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Sample records for axxent electronic brachytherapy

  1. SU-E-T-171: Characterization of the New Xoft Axxent Electronic Brachytherapy Source Using PRESAGE Dosimeters

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    Steinmann, A; Followill, D; Ibbott, G [UT MD Anderson Cancer Center, Houston, TX (United States); Adamovics, J [John Adamovics, Skillman, NJ (United States)

    2015-06-15

    Purpose: To characterize the Xoft Axxent electronic brachytherapy source using PRESAGE™ dosimeters to obtain independent confirmation of TG-43U1 dosimetry values from previous studies and ascertain its reproducibility in HDR brachytherapy. Methods: PRESAGE™ dosimeters are solid, polyurethane-based dosimeters doped with radiochromic leucodyes that produce a linear optical-density response when exposed to radiation. Eight 1-kg dosimeters were scanned prior to irradiation on an optical-CT scanner to eliminate background signal and any optical imperfections from each dosimeter. To quantify potential imaging artifacts due to oversaturated responses in the immediate range of the source, half of the eight dosimeters were cast with a smaller channel diameter of 5.4 mm, and the other half were cast with a larger channel diameter of 15mm. During irradiation, the catheters were placed in the center of each channel. Catheters fit the 5.4mm diameters channels whereas polyurethane plugs were inserted into the larger channels to create a sturdy, immobile catheter which allowed uniform dose distributions. Two dosimeters of each 5.4mm and 15mm were irradiated at either 1517.3 cGy or 2017.5 cGy. Post-irradiation scans were performed within 48 hours of irradiation. A 3D reconstruction based on subtraction of these two images and the relative dose measurements were made using in-house software. Results: Comparing measured radial dose rates with previous results revealed smaller percent errors when PRESAGE™ irradiations were at lower maximum dose. The dosimeters showed small deviations in radial dose function, g{sub p} (r), from previous studies. Among the dosimeters irradiated at 1517.3 cGy, the g{sub p}(r) compared to previous studies fluctuated from 0.0043 to 0.3922. This suggests small fluctuations can drastically change radial dose calculations. Conclusion: The subtraction of pre-irradiation and post-irradiation scans of PRESAGE™ dosimeters using an optical-CT scanner

  2. SU-F-BRA-09: New Efficient Method for Xoft Axxent Electronic Brachytherapy Source Calibration by Pre-Characterizing Surface Applicators

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    Pai, S [iCAD Inc., Los Gatos, CA (United States)

    2015-06-15

    Purpose: The objective is to improve the efficiency and efficacy of Xoft™ Axxent™ electronic brachytherapy (EBT) calibration of the source & surface applicator using AAPM TG-61 formalism. Methods: Current method of Xoft EBT source calibration involves determination of absolute dose rate of the source in each of the four conical surface applicators using in-air chamber measurements & TG61 formalism. We propose a simplified TG-61 calibration methodology involving initial characterization of surface cone applicators. This is accomplished by calibrating dose rates for all 4 surface applicator sets (for 10 sources) which establishes the “applicator output ratios” with respect to the selected reference applicator (20 mm applicator). After the initial time, Xoft™ Axxent™ source TG61 Calibration is carried out only in the reference applicator. Using the established applicator output ratios, dose rates for other applicators will be calculated. Results: 200 sources & 8 surface applicator sets were calibrated cumulatively using a Standard Imaging A20 ion-chamber in accordance with manufacturer-recommended protocols. Dose rates of 10, 20, 35 & 50mm applicators were normalized to the reference (20mm) applicator. The data in Figure 1 indicates that the normalized dose rate variation for each applicator for all 200 sources is better than ±3%. The average output ratios are 1.11, 1.02 and 0.49 for the 10 mm,35 mm and 50 mm applicators, respectively, which are in good agreement with the manufacturer’s published output ratios of 1.13, 1.02 and 0.49. Conclusion: Our measurements successfully demonstrate the accuracy of a new calibration method using a single surface applicator for Xoft EBT sources and deriving the dose rates of other applicators. The accuracy of the calibration is improved as this method minimizes the source position variation inside the applicator during individual source calibrations. The new method significantly reduces the calibration time to less

  3. Electronic brachytherapy management of atypical fibroxanthoma: report of 8 lesions

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    Stephen Doggett

    2017-01-01

    Full Text Available Purpose : To evaluate the suitability of treating atypical fibroxanthoma (AFX, an uncommon skin malignancy, with electronic brachytherapy. Material and methods : From Feb 2013 to Sep 2014, we were referred a total of 8 cases of AFX in 7 patients, all involving the scalp. All of them were treated with electronic brachytherapy 50 Kev radiations (Xoft Axxent®, Fremont, California. All lesions received 40 Gy in two fractions per week with 5mm margins. Results : At a median follow-up of 23.7 months, the local recurrence rate is 12.5%. The single lesion that failed was not debulked surgically prior to electronic brachytherapy. Conclusions : To our knowledge, this is the first report in the literature on the use of radiation therapy as curative primary treatment for AFX. No contraindication to the use of radiations is found in the literature, with surgery being the sole treatment for AFX noted. Our recurrence rate is 0% for debulked lesions. Risk of recurrence is mitigated with surgical debulking prior to brachytherapy. Electronic brachytherapy appears to be a safe and effective treatment for debulked AFX. Multiple excisions, skin grafting, and wound care can be avoided in elderly patients by the use of electronic brachytherapy.

  4. A comparison of the relative biological effectiveness of low energy electronic brachytherapy sources in breast tissue: a Monte Carlo study

    Science.gov (United States)

    White, Shane A.; Reniers, Brigitte; de Jong, Evelyn E. C.; Rusch, Thomas; Verhaegen, Frank

    2016-01-01

    Electronic brachytherapy sources use low energy photons to treat the tumor bed during or after breast-conserving surgery. The relative biological effectiveness of two electronic brachytherapy sources was explored to determine if spectral differences due to source design influenced radiation quality and if radiation quality decreased with distance in the breast. The RBE was calculated through the number of DNA double strand breaks (RBEDSB) using the Monte Carlo damage simulator (MCDS) in combination with other Monte Carlo electron/photon spectrum calculations. 50kVp photons from the Intrabeam (Carl Zeiss Surgical) and Axxent (Xoft) through 40-mm spherical applicators were simulated to account for applicator and tissue attenuation in a variety of breast tissue compositions. 40kVp Axxent photons were also simulated. Secondary electrons (known to be responsible for most DNA damage) spectra at different distance were inputted into MCDS to calculate the RBEDSB. All RBEDSB used a cobalt-60 reference. RBEDSB data was combined with corresponding average photon spectrum energy for the Axxent and applied to model-based average photon energy distributions to produce an RBEDSB map of an accelerated partial breast irradiation (APBI) patient. Both Axxent and Intrabeam 50kVp spectra were shown to have a comparable RBEDSB of between 1.4 and 1.6 at all distances in spite of progressive beam hardening. The Axxent 40kVp also demonstrated a similar RBEDSB at distances. Most RBEDSB variability was dependent on the tissue type as was seen in rib (RBEDSB  ≈  1.4), gland (≈1.55), adipose (≈1.59), skin (≈1.52) and lung (≈1.50). RBEDSB variability between both sources was within 2%. A correlation was shown between RBEDSB and average photon energy and used to produce an RBEDSB map of a dose distribution in an APBI patient dataset. Radiation quality is very similar between electronic brachytherapy sources studied. No significant reductions in RBEDSB were observed with

  5. American Society for Therapeutic Radiology and Oncology (ASTRO) Emerging Technology Committee report on electronic brachytherapy.

    Science.gov (United States)

    Park, Catherine C; Yom, Sue S; Podgorsak, Matthew B; Harris, Eleanor; Price, Robert A; Bevan, Alison; Pouliot, Jean; Konski, Andre A; Wallner, Paul E

    2010-03-15

    The development of novel technologies for the safe and effective delivery of radiation is critical to advancing the field of radiation oncology. The Emerging Technology Committee of the American Society for Therapeutic Radiology and Oncology appointed a Task Group within its Evaluation Subcommittee to evaluate new electronic brachytherapy methods that are being developed for, or are already in, clinical use. The Task Group evaluated two devices, the Axxent Electronic Brachytherapy System by Xoft, Inc. (Fremont, CA), and the Intrabeam Photon Radiosurgery Device by Carl Zeiss Surgical (Oberkochen, Germany). These devices are designed to deliver electronically generated radiation, and because of their relatively low energy output, they do not fall under existing regulatory scrutiny of radioactive sources that are used for conventional radioisotope brachytherapy. This report provides a descriptive overview of the technologies, current and future projected applications, comparison of competing technologies, potential impact, and potential safety issues. The full Emerging Technology Committee report is available on the American Society for Therapeutic Radiology and Oncology Web site.

  6. Prospective multi-center trial utilizing electronic brachytherapy for the treatment of endometrial cancer

    Directory of Open Access Journals (Sweden)

    Thropay John P

    2010-07-01

    Full Text Available Abstract Background A modified form of high dose rate (HDR brachytherapy has been developed called Axxent Electronic Brachytherapy (EBT. EBT uses a kilovolt X-ray source and does not require treatment in a shielded vault or a HDR afterloader unit. A multi-center clinical study was carried out to evaluate the success of treatment delivery, safety and toxicity of EBT in patients with endometrial cancer. Methods A total of 15 patients with stage I or II endometrial cancer were enrolled at 5 sites. Patients were treated with vaginal EBT alone or in combination with external beam radiation. Results The prescribed doses of EBT were successfully delivered in all 15 patients. From the first fraction through 3 months follow-up, there were 4 CTC Grade 1 adverse events and 2 CTC Grade II adverse events reported that were EBT related. The mild events reported were dysuria, vaginal dryness, mucosal atrophy, and rectal bleeding. The moderate treatment related adverse events included dysuria, and vaginal pain. No Grade III or IV adverse events were reported. The EBT system performed well and was associated with limited acute toxicities. Conclusions EBT shows acute results similar to HDR brachytherapy. Additional research is needed to further assess the clinical efficacy and safety of EBT in the treatment of endometrial cancer.

  7. Design and dosimetric characteristics of a new endocavitary contact radiotherapy system using an electronic brachytherapy source

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    Richardson, Susan; Garcia-Ramirez, Jose; Lu Wei; Myerson, Robert J.; Parikh, Parag [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States); Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland 21201 (United States); Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States)

    2012-11-15

    Purpose: To present design aspects and acceptance tests performed for clinical implementation of electronic brachytherapy treatment of early stage rectal adenocarcinoma. A dosimetric comparison is made between the historically used Philips RT-50 unit and the newly developed Axxent{sup Registered-Sign} Model S700 electronic brachytherapy source manufactured by Xoft (iCad, Inc.). Methods: Two proctoscope cones were manufactured by ElectroSurgical Instruments (ESI). Two custom surface applicators were manufactured by Xoft and were designed to fit and interlock with the proctoscope cones from ESI. Dose rates, half value layers (HVL), and percentage depth dose (PDD) measurements were made with the Xoft system and compared to historical RT-50 data. A description of the patient treatment approach and exposure rates during the procedure is also provided. Results: The electronic brachytherapy system has a lower surface dose rate than the RT-50. The dose rate to water on the surface from the Xoft system is approximately 2.1 Gy/min while the RT-50 is 10-12 Gy/min. However, treatment times with Xoft are still reasonable. The HVLs and PDDs between the two systems were comparable resulting in similar doses to the target and to regions beyond the target. The exposure rate levels around a patient treatment were acceptable. The standard uncertainty in the dose rate to water on the surface is approximately {+-}5.2%. Conclusions: The Philips RT-50 unit is an out-of-date radiotherapy machine that is no longer manufactured with limited replacement parts. The use of a custom-designed proctoscope and Xoft surface applicators allows delivery of a well-established treatment with the ease of a modern radiotherapy device. While the dose rate is lower with the use of Xoft, the treatment times are still reasonable. Additionally, personnel may stand farther away from the Xoft radiation source, thus potentially reducing radiation exposure to the operator and other personnel.

  8. MO-D-BRD-00: Electronic Brachytherapy

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    NONE

    2015-06-15

    Electronic brachytherapy (eBT) has seen an insurgence of manufacturers entering the US market for use in radiation therapy. In addition to the established interstitial, intraluminary, and intracavitary applications of eBT, many centers are now using eBT to treat skin lesions. It is important for medical physicists working with electronic brachytherapy sources to understand the basic physics principles of the sources themselves as well as the variety of applications for which they are being used. The calibration of the sources is different from vendor to vendor and the traceability of calibrations has evolved as new sources came to market. In 2014, a new air-kerma based standard was introduced by the National Institute of Standards and Technology (NIST) to measure the output of an eBT source. Eventually commercial treatment planning systems should accommodate this new standard and provide NIST traceability to the end user. The calibration and commissioning of an eBT system is unique to its application and typically entails a list of procedural recommendations by the manufacturer. Commissioning measurements are performed using a variety of methods, some of which are modifications of existing AAPM Task Group protocols. A medical physicist should be familiar with the different AAPM Task Group recommendations for applicability to eBT and how to properly adapt them to their needs. In addition to the physical characteristics of an eBT source, the photon energy is substantially lower than from HDR Ir-192 sources. Consequently, tissue-specific dosimetry and radiobiological considerations are necessary when comparing these brachytherapy modalities and when making clinical decisions as a radiation therapy team. In this session, the physical characteristics and calibration methodologies of eBt sources will be presented as well as radiobiology considerations and other important clinical considerations. Learning Objectives: To understand the basic principles of electronic

  9. Applications of tissue heterogeneity corrections and biologically effective dose volume histograms in assessing the doses for accelerated partial breast irradiation using an electronic brachytherapy source

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    Shi Chengyu; Guo Bingqi; Eng, Tony; Papanikolaou, Nikos [Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, TX 78229 (United States); Cheng, Chih-Yao, E-mail: shic@uthscsa.ed [Radiation Oncology Department, Oklahoma University Health Science Center, Oklahoma, OK 73104 (United States)

    2010-09-21

    A low-energy electronic brachytherapy source (EBS), the model S700 Axxent(TM) x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V{sub 100} reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as

  10. Comparison of TG-43 and TG-186 in breast irradiation using a low energy electronic brachytherapy source

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    White, Shane A.; Landry, Guillaume; Reniers, Brigitte, E-mail: brigitte.reniers@maastro.nl [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN (Netherlands); Fonseca, Gabriel Paiva [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN, The Netherlands and Instituto de Pesquisas Energéticas e Nucleares – IPEN-CNEN/SP, São Paulo CP 11049, 05422-970 (Brazil); Holt, Randy; Rusch, Thomas [Xoft, A Subsidiary of iCAD, Sunnyvale, California 94085-4115 (United States); Beaulieu, Luc [Centre Hospitalier Universitaire de Québec Université Laval, Radio-Oncologie et Centre de Recherche en Cancérologie de l’Université Laval, Québec, Québec G1R 2J6 Canada (Canada); Verhaegen, Frank [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN, The Netherlands and Department of Oncology, McGill University, Montreal, Quebec H3G 1A4 (Canada)

    2014-06-15

    Purpose: The recently updated guidelines for dosimetry in brachytherapy in TG-186 have recommended the use of model-based dosimetry calculations as a replacement for TG-43. TG-186 highlights shortcomings in the water-based approach in TG-43, particularly for low energy brachytherapy sources. The Xoft Axxent is a low energy (<50 kV) brachytherapy system used in accelerated partial breast irradiation (APBI). Breast tissue is a heterogeneous tissue in terms of density and composition. Dosimetric calculations of seven APBI patients treated with Axxent were made using a model-based Monte Carlo platform for a number of tissue models and dose reporting methods and compared to TG-43 based plans. Methods: A model of the Axxent source, the S700, was created and validated against experimental data. CT scans of the patients were used to create realistic multi-tissue/heterogeneous models with breast tissue segmented using a published technique. Alternative water models were used to isolate the influence of tissue heterogeneity and backscatter on the dose distribution. Dose calculations were performed using Geant4 according to the original treatment parameters. The effect of the Axxent balloon applicator used in APBI which could not be modeled in the CT-based model, was modeled using a novel technique that utilizes CAD-based geometries. These techniques were validated experimentally. Results were calculated using two dose reporting methods, dose to water (D{sub w,m}) and dose to medium (D{sub m,m}), for the heterogeneous simulations. All results were compared against TG-43-based dose distributions and evaluated using dose ratio maps and DVH metrics. Changes in skin and PTV dose were highlighted. Results: All simulated heterogeneous models showed a reduced dose to the DVH metrics that is dependent on the method of dose reporting and patient geometry. Based on a prescription dose of 34 Gy, the average D{sub 90} to PTV was reduced by between ∼4% and ∼40%, depending on the

  11. Patient-specific Monte Carlo-based dose-kernel approach for inverse planning in afterloading brachytherapy.

    Science.gov (United States)

    D'Amours, Michel; Pouliot, Jean; Dagnault, Anne; Verhaegen, Frank; Beaulieu, Luc

    2011-12-01

    Brachytherapy planning software relies on the Task Group report 43 dosimetry formalism. This formalism, based on a water approximation, neglects various heterogeneous materials present during treatment. Various studies have suggested that these heterogeneities should be taken into account to improve the treatment quality. The present study sought to demonstrate the feasibility of incorporating Monte Carlo (MC) dosimetry within an inverse planning algorithm to improve the dose conformity and increase the treatment quality. The method was based on precalculated dose kernels in full patient geometries, representing the dose distribution of a brachytherapy source at a single dwell position using MC simulations and the Geant4 toolkit. These dose kernels are used by the inverse planning by simulated annealing tool to produce a fast MC-based plan. A test was performed for an interstitial brachytherapy breast treatment using two different high-dose-rate brachytherapy sources: the microSelectron iridium-192 source and the electronic brachytherapy source Axxent operating at 50 kVp. A research version of the inverse planning by simulated annealing algorithm was combined with MC to provide a method to fully account for the heterogeneities in dose optimization, using the MC method. The effect of the water approximation was found to depend on photon energy, with greater dose attenuation for the lower energies of the Axxent source compared with iridium-192. For the latter, an underdosage of 5.1% for the dose received by 90% of the clinical target volume was found. A new method to optimize afterloading brachytherapy plans that uses MC dosimetric information was developed. Including computed tomography-based information in MC dosimetry in the inverse planning process was shown to take into account the full range of scatter and heterogeneity conditions. This led to significant dose differences compared with the Task Group report 43 approach for the Axxent source. Copyright © 2011

  12. Patient-Specific Monte Carlo-Based Dose-Kernel Approach for Inverse Planning in Afterloading Brachytherapy

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    D' Amours, Michel [Departement de Radio-Oncologie et Centre de Recherche en Cancerologie de l' Universite Laval, Hotel-Dieu de Quebec, Quebec, QC (Canada); Department of Physics, Physics Engineering, and Optics, Universite Laval, Quebec, QC (Canada); Pouliot, Jean [Department of Radiation Oncology, University of California, San Francisco, School of Medicine, San Francisco, CA (United States); Dagnault, Anne [Departement de Radio-Oncologie et Centre de Recherche en Cancerologie de l' Universite Laval, Hotel-Dieu de Quebec, Quebec, QC (Canada); Verhaegen, Frank [Department of Radiation Oncology, Maastro Clinic, GROW Research Institute, Maastricht University Medical Centre, Maastricht (Netherlands); Department of Oncology, McGill University, Montreal, QC (Canada); Beaulieu, Luc, E-mail: beaulieu@phy.ulaval.ca [Departement de Radio-Oncologie et Centre de Recherche en Cancerologie de l' Universite Laval, Hotel-Dieu de Quebec, Quebec, QC (Canada); Department of Physics, Physics Engineering, and Optics, Universite Laval, Quebec, QC (Canada)

    2011-12-01

    Purpose: Brachytherapy planning software relies on the Task Group report 43 dosimetry formalism. This formalism, based on a water approximation, neglects various heterogeneous materials present during treatment. Various studies have suggested that these heterogeneities should be taken into account to improve the treatment quality. The present study sought to demonstrate the feasibility of incorporating Monte Carlo (MC) dosimetry within an inverse planning algorithm to improve the dose conformity and increase the treatment quality. Methods and Materials: The method was based on precalculated dose kernels in full patient geometries, representing the dose distribution of a brachytherapy source at a single dwell position using MC simulations and the Geant4 toolkit. These dose kernels are used by the inverse planning by simulated annealing tool to produce a fast MC-based plan. A test was performed for an interstitial brachytherapy breast treatment using two different high-dose-rate brachytherapy sources: the microSelectron iridium-192 source and the electronic brachytherapy source Axxent operating at 50 kVp. Results: A research version of the inverse planning by simulated annealing algorithm was combined with MC to provide a method to fully account for the heterogeneities in dose optimization, using the MC method. The effect of the water approximation was found to depend on photon energy, with greater dose attenuation for the lower energies of the Axxent source compared with iridium-192. For the latter, an underdosage of 5.1% for the dose received by 90% of the clinical target volume was found. Conclusion: A new method to optimize afterloading brachytherapy plans that uses MC dosimetric information was developed. Including computed tomography-based information in MC dosimetry in the inverse planning process was shown to take into account the full range of scatter and heterogeneity conditions. This led to significant dose differences compared with the Task Group report

  13. Brachytherapy

    Science.gov (United States)

    ... days. A patient receiving LDR brachytherapy will stay overnight at the hospital. This is so the delivery device can remain in place throughout the treatment period. Pulsed dose-rate (PDR) brachytherapy is delivered in a similar way, ...

  14. Brachytherapy in breast cancer: an effective alternative

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    Janusz Skowronek

    2014-03-01

    Full Text Available Breast conserving surgery (BCS with following external beam radiation therapy (EBRT of the conserved breast has become widely accepted in the last decades for the treatment of early invasive breast cancer. The standard technique of EBRT after BCS is to treat the whole breast up to a total dose of 42.5 to 50 Gy. An additional dose is given to treated volume as a boost to a portion of the breast. In the early stage of breast cancer, research has shown that the area requiring radiation treatment to prevent the cancer from local recurrence is the breast tissue that surrounds the area where the initial cancer was removed. Accelerated partial breast irradiation (APBI is an approach that treats only the lumpectomy bed plus a 1-2 cm margin rather than the whole breast and as a result allows accelerated delivery of the radiation dose in four to five days. There has been a growing interest for APBI and various approaches have been developed under phase I-III clinical studies; these include multicatheter interstitial brachytherapy, balloon catheter brachytherapy, conformal external beam radiation therapy (3D-EBRT and intra-operative radiation therapy (IORT. Balloon-based brachytherapy approaches include MammoSite, Axxent electronic brachytherapy, Contura, hybrid brachytherapy devices. Another indication for breast brachytherapy is reirradiation of local recurrence after mastectomy. Published results of brachytherapy are very promising. We discuss the current status, indications, and technical aspects of breast cancer brachytherapy.

  15. Simulation evaluation of NIST air-kerma rate calibration standard for electronic brachytherapy.

    Science.gov (United States)

    Hiatt, Jessica R; Rivard, Mark J; Hughes, H Grady

    2016-03-01

    Dosimetry for the model S700 50 kV electronic brachytherapy (eBT) source (Xoft, Inc., a subsidiary of iCAD, San Jose, CA) was simulated using Monte Carlo (MC) methods by Rivard et al. ["Calculated and measured brachytherapy dosimetry parameters in water for the Xoft Axxent x-ray source: An electronic brachytherapy source," Med. Phys. 33, 4020-4032 (2006)] and recently by Hiatt et al. ["A revised dosimetric characterization of the model S700 electronic brachytherapy source containing an anode-centering plastic insert and other components not included in the 2006 model," Med. Phys. 42, 2764-2776 (2015)] with improved geometric characterization. While these studies examined the dose distribution in water, there have not previously been reports of the eBT source calibration methods beyond that recently reported by Seltzer et al. ["New national air-kerma standard for low-energy electronic brachytherapy sources," J. Res. Natl. Inst. Stand. Technol. 119, 554-574 (2014)]. Therefore, the motivation for the current study was to provide an independent determination of air-kerma rate at 50 cm in air K̇air(d=50 cm) using MC methods for the model S700 eBT source. Using CAD information provided by the vendor and disassembled sources, an MC model was created for the S700 eBT source. Simulations were run using the mcnp6 radiation transport code for the NIST Lamperti air ionization chamber according to specifications by Boutillon et al. ["Comparison of exposure standards in the 10-50 kV x-ray region," Metrologia 5, 1-11 (1969)], in air without the Lamperti chamber, and in vacuum without the Lamperti chamber. K̇air(d=50 cm) was determined using the *F4 tally with NIST values for the mass energy-absorption coefficients for air. Photon spectra were evaluated over 2 π azimuthal sampling for polar angles of 0° ≤ θ ≤ 180° every 1°. Volume averaging was averted through tight radial binning. Photon energy spectra were determined over all polar angles in both air and vacuum using

  16. SU-E-T-421: Failure Mode and Effects Analysis (FMEA) of Xoft Electronic Brachytherapy for the Treatment of Superficial Skin Cancers

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    Hoisak, J; Manger, R; Dragojevic, I [University of California San Diego, La Jolla, CA (United States)

    2015-06-15

    Purpose: To perform a failure mode and effects analysis (FMEA) of the process for treating superficial skin cancers with the Xoft Axxent electronic brachytherapy (eBx) system, given the recent introduction of expanded quality control (QC) initiatives at our institution. Methods: A process map was developed listing all steps in superficial treatments with Xoft eBx, from the initial patient consult to the completion of the treatment course. The process map guided the FMEA to identify the failure modes for each step in the treatment workflow and assign Risk Priority Numbers (RPN), calculated as the product of the failure mode’s probability of occurrence (O), severity (S) and lack of detectability (D). FMEA was done with and without the inclusion of recent QC initiatives such as increased staffing, physics oversight, standardized source calibration, treatment planning and documentation. The failure modes with the highest RPNs were identified and contrasted before and after introduction of the QC initiatives. Results: Based on the FMEA, the failure modes with the highest RPN were related to source calibration, treatment planning, and patient setup/treatment delivery (Fig. 1). The introduction of additional physics oversight, standardized planning and safety initiatives such as checklists and time-outs reduced the RPNs of these failure modes. High-risk failure modes that could be mitigated with improved hardware and software interlocks were identified. Conclusion: The FMEA analysis identified the steps in the treatment process presenting the highest risk. The introduction of enhanced QC initiatives mitigated the risk of some of these failure modes by decreasing their probability of occurrence and increasing their detectability. This analysis demonstrates the importance of well-designed QC policies, procedures and oversight in a Xoft eBx programme for treatment of superficial skin cancers. Unresolved high risk failure modes highlight the need for non-procedural quality

  17. Novel treatment options for nonmelanoma skin cancer: focus on electronic brachytherapy

    Directory of Open Access Journals (Sweden)

    Kasper ME

    2015-11-01

    Full Text Available Michael E Kasper,1,2 Ahmed A Chaudhary3 1Department of Radiation Oncology, Lynn Cancer Institute at Boca Raton Regional Hospital, Boca Raton, 2Charles E. Schmidt College of Medicine, Florida Atlantic University, FL, 3North Main Radiation Oncology, Warren Alpert School of Medicine, Brown University, RI, USA Abstract: Nonmelanoma skin cancer (NMSC is an increasing health care issue in the United States, significantly affecting quality of life and impacting health care costs. Radiotherapy has a long history in the treatment of NMSC. Shortly after the discovery of X-rays and 226Radium, physicians cured patients with NMSC using these new treatments. Both X-ray therapy and brachytherapy have evolved over the years, ultimately delivering higher cure rates and lower toxicity. Electronic brachytherapy for NMSC is based on the technical and clinical data obtained from radionuclide skin surface brachytherapy and the small skin surface applicators developed over the past 25 years. The purpose of this review is to introduce electronic brachytherapy in the context of the history, data, and utilization of traditional radiotherapy and brachytherapy. Keywords: electronic brachytherapy, superficial radiotherapy, skin surface brachytherapy, electron beam therapy, nonmelanoma skin cancer, basal cell carcinoma, squamous cell carcinoma

  18. Two years results of electronic brachytherapy for basal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Rosa Ballester-Sánchez

    2017-06-01

    Full Text Available Purpose: The use of radiation therapy (RT for non-melanoma skin cancer (NMSC has been changing throughout the last century. Over the last decades, the use of radiotherapy has surged with the development of new techniques, applicators, and devices. In recent years, electronic brachytherapy (eBT devices that use small x-ray sources have been introduced as alternative to radionuclide dependence. Nowadays, several devices have been incorporated, with a few series reported, and with a short follow-up, due to the recent introduction of these systems. The purpose of this work is to describe the clinical results of our series after two years follow-up with a specific eBT system. Material and methods: This is a prospective single-center, non-randomized pilot study, to assess clinical results of electronic brachytherapy in basal cell carcinoma using the Esteya® system. In 2014, 40 patients with 60 lesions were treated. Patient follow-up on a regular basis was performed for a period of two years. Results: Twenty-six patients with 44 lesions achieved two years follow-up. A complete response was documented in 95.5% of cases. Toxicity was mild (G1 or G2 in all cases, caused by erythema, erosion, or alopecia. Cosmesis was excellent in 88.6% of cases, and good in the rest. Change in pigmentation was the most frequent cosmetic alteration. Conclusions : This work is special, since the equipment’s treatment voltage was 69.5 kV, and this is the first prospective study with long term follow-up with Esteya®. These preliminary report show excellent results with less toxicity and excellent cosmesis. While surgery has been the treatment of choice, certain patients might benefit from eBT treatment. These are elderly patients with comorbidities or undergoing anticoagulant treatment as well as those who simply refuse surgery or might have other contraindications.

  19. Characteristics of miniature electronic brachytherapy x-ray sources based on TG-43U1 formalism using Monte Carlo simulation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Safigholi, Habib; Faghihi, Reza; Jashni, Somaye Karimi; Meigooni, Ali S. [Faculty of Engineering, Science and Research Branch, Islamic Azad University, Fars, 73481-13111, Persepolis (Iran, Islamic Republic of); Department of Nuclear Engineering and Radiation Research Center, Shiraz University, 71936-16548, Shiraz (Iran, Islamic Republic of); Shiraz University of Medical Sciences, 71348-14336, Shiraz (Iran, Islamic Republic of); Department of Radiation therapy, Comprehensive Cancer Center of Nevada, 3730 South Eastern Avenue, Las Vegas, Nevada 89169 (United States)

    2012-04-15

    Purpose: The goal of this study is to determine a method for Monte Carlo (MC) characterization of the miniature electronic brachytherapy x-ray sources (MEBXS) and to set dosimetric parameters according to TG-43U1 formalism. TG-43U1 parameters were used to get optimal designs of MEBXS. Parameters that affect the dose distribution such as anode shapes, target thickness, target angles, and electron beam source characteristics were evaluated. Optimized MEBXS designs were obtained and used to determine radial dose functions and 2D anisotropy functions in the electron energy range of 25-80 keV. Methods: Tungsten anode material was considered in two different geometries, hemispherical and conical-hemisphere. These configurations were analyzed by the 4C MC code with several different optimization techniques. The first optimization compared target thickness layers versus electron energy. These optimized thicknesses were compared with published results by Ihsan et al.[Nucl. Instrum. Methods Phys. Res. B 264, 371-377 (2007)]. The second optimization evaluated electron source characteristics by changing the cathode shapes and electron energies. Electron sources studied included; (1) point sources, (2) uniform cylinders, and (3) nonuniform cylindrical shell geometries. The third optimization was used to assess the apex angle of the conical-hemisphere target. The goal of these optimizations was to produce 2D-dose anisotropy functions closer to unity. An overall optimized MEBXS was developed from this analysis. The results obtained from this model were compared to known characteristics of HDR {sup 125}I, LDR {sup 103}Pd, and Xoft Axxent electronic brachytherapy source (XAEBS) [Med. Phys. 33, 4020-4032 (2006)]. Results: The optimized anode thicknesses as a function of electron energy is fitted by the linear equation Y ({mu}m) = 0.0459X (keV)-0.7342. The optimized electron source geometry is obtained for a disk-shaped parallel beam (uniform cylinder) with 0.9 mm radius. The TG-43

  20. MO-D-BRD-04: NIST Air-Kerma Standard for Electronic Brachytherapy Calibrations

    Energy Technology Data Exchange (ETDEWEB)

    Mitch, M. [Nat’l Institute of Standards & Technology (United States)

    2015-06-15

    Electronic brachytherapy (eBT) has seen an insurgence of manufacturers entering the US market for use in radiation therapy. In addition to the established interstitial, intraluminary, and intracavitary applications of eBT, many centers are now using eBT to treat skin lesions. It is important for medical physicists working with electronic brachytherapy sources to understand the basic physics principles of the sources themselves as well as the variety of applications for which they are being used. The calibration of the sources is different from vendor to vendor and the traceability of calibrations has evolved as new sources came to market. In 2014, a new air-kerma based standard was introduced by the National Institute of Standards and Technology (NIST) to measure the output of an eBT source. Eventually commercial treatment planning systems should accommodate this new standard and provide NIST traceability to the end user. The calibration and commissioning of an eBT system is unique to its application and typically entails a list of procedural recommendations by the manufacturer. Commissioning measurements are performed using a variety of methods, some of which are modifications of existing AAPM Task Group protocols. A medical physicist should be familiar with the different AAPM Task Group recommendations for applicability to eBT and how to properly adapt them to their needs. In addition to the physical characteristics of an eBT source, the photon energy is substantially lower than from HDR Ir-192 sources. Consequently, tissue-specific dosimetry and radiobiological considerations are necessary when comparing these brachytherapy modalities and when making clinical decisions as a radiation therapy team. In this session, the physical characteristics and calibration methodologies of eBt sources will be presented as well as radiobiology considerations and other important clinical considerations. Learning Objectives: To understand the basic principles of electronic

  1. MO-D-BRD-03: Radiobiology and Commissioning of Electronic Brachytherapy for IORT

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J. [Oregon Health & Science Univ (United States)

    2015-06-15

    Electronic brachytherapy (eBT) has seen an insurgence of manufacturers entering the US market for use in radiation therapy. In addition to the established interstitial, intraluminary, and intracavitary applications of eBT, many centers are now using eBT to treat skin lesions. It is important for medical physicists working with electronic brachytherapy sources to understand the basic physics principles of the sources themselves as well as the variety of applications for which they are being used. The calibration of the sources is different from vendor to vendor and the traceability of calibrations has evolved as new sources came to market. In 2014, a new air-kerma based standard was introduced by the National Institute of Standards and Technology (NIST) to measure the output of an eBT source. Eventually commercial treatment planning systems should accommodate this new standard and provide NIST traceability to the end user. The calibration and commissioning of an eBT system is unique to its application and typically entails a list of procedural recommendations by the manufacturer. Commissioning measurements are performed using a variety of methods, some of which are modifications of existing AAPM Task Group protocols. A medical physicist should be familiar with the different AAPM Task Group recommendations for applicability to eBT and how to properly adapt them to their needs. In addition to the physical characteristics of an eBT source, the photon energy is substantially lower than from HDR Ir-192 sources. Consequently, tissue-specific dosimetry and radiobiological considerations are necessary when comparing these brachytherapy modalities and when making clinical decisions as a radiation therapy team. In this session, the physical characteristics and calibration methodologies of eBt sources will be presented as well as radiobiology considerations and other important clinical considerations. Learning Objectives: To understand the basic principles of electronic

  2. MO-D-BRD-02: Radiological Physics and Surface Lesion Treatments with Electronic Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Fulkerson, R.

    2015-06-15

    Electronic brachytherapy (eBT) has seen an insurgence of manufacturers entering the US market for use in radiation therapy. In addition to the established interstitial, intraluminary, and intracavitary applications of eBT, many centers are now using eBT to treat skin lesions. It is important for medical physicists working with electronic brachytherapy sources to understand the basic physics principles of the sources themselves as well as the variety of applications for which they are being used. The calibration of the sources is different from vendor to vendor and the traceability of calibrations has evolved as new sources came to market. In 2014, a new air-kerma based standard was introduced by the National Institute of Standards and Technology (NIST) to measure the output of an eBT source. Eventually commercial treatment planning systems should accommodate this new standard and provide NIST traceability to the end user. The calibration and commissioning of an eBT system is unique to its application and typically entails a list of procedural recommendations by the manufacturer. Commissioning measurements are performed using a variety of methods, some of which are modifications of existing AAPM Task Group protocols. A medical physicist should be familiar with the different AAPM Task Group recommendations for applicability to eBT and how to properly adapt them to their needs. In addition to the physical characteristics of an eBT source, the photon energy is substantially lower than from HDR Ir-192 sources. Consequently, tissue-specific dosimetry and radiobiological considerations are necessary when comparing these brachytherapy modalities and when making clinical decisions as a radiation therapy team. In this session, the physical characteristics and calibration methodologies of eBt sources will be presented as well as radiobiology considerations and other important clinical considerations. Learning Objectives: To understand the basic principles of electronic

  3. MO-D-BRD-01: Clinical Implementation of An Electronic Brachytherapy Program for the Skin

    Energy Technology Data Exchange (ETDEWEB)

    Ouhib, Z. [Lynn Regional Cancer Center (United States)

    2015-06-15

    Electronic brachytherapy (eBT) has seen an insurgence of manufacturers entering the US market for use in radiation therapy. In addition to the established interstitial, intraluminary, and intracavitary applications of eBT, many centers are now using eBT to treat skin lesions. It is important for medical physicists working with electronic brachytherapy sources to understand the basic physics principles of the sources themselves as well as the variety of applications for which they are being used. The calibration of the sources is different from vendor to vendor and the traceability of calibrations has evolved as new sources came to market. In 2014, a new air-kerma based standard was introduced by the National Institute of Standards and Technology (NIST) to measure the output of an eBT source. Eventually commercial treatment planning systems should accommodate this new standard and provide NIST traceability to the end user. The calibration and commissioning of an eBT system is unique to its application and typically entails a list of procedural recommendations by the manufacturer. Commissioning measurements are performed using a variety of methods, some of which are modifications of existing AAPM Task Group protocols. A medical physicist should be familiar with the different AAPM Task Group recommendations for applicability to eBT and how to properly adapt them to their needs. In addition to the physical characteristics of an eBT source, the photon energy is substantially lower than from HDR Ir-192 sources. Consequently, tissue-specific dosimetry and radiobiological considerations are necessary when comparing these brachytherapy modalities and when making clinical decisions as a radiation therapy team. In this session, the physical characteristics and calibration methodologies of eBt sources will be presented as well as radiobiology considerations and other important clinical considerations. Learning Objectives: To understand the basic principles of electronic

  4. Evaluation of high-energy brachytherapy source electronic disequilibrium and dose from emitted electrons

    Energy Technology Data Exchange (ETDEWEB)

    Ballester, Facundo; Granero, Domingo; Perez-Calatayud, Jose; Melhus, Christopher S.; Rivard, Mark J. [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, C/Dr. Moliner 50, E-46100 Burjassot (Spain) and IFIC, CSIC-University of Valencia, C/Dr. Moliner 50, E-46100 Burjassot (Spain); Department of Radiation Physics, ERESA, Hospital General Universitario, Avenida Tres Cruces, 2, E-46014 Valencia (Spain); Department of Radiation Oncology, La Fe University Hospital, Avenida Campanar 21, E-46009 Valencia (Spain); Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States)

    2009-09-15

    Purpose: The region of electronic disequilibrium near photon-emitting brachytherapy sources of high-energy radionuclides ({sup 60}Co, {sup 137}Cs, {sup 192}Ir, and {sup 169}Yb) and contributions to total dose from emitted electrons were studied using the GEANT4 and PENELOPE Monte Carlo codes. Methods: Hypothetical sources with active and capsule materials mimicking those of actual sources but with spherical shape were examined. Dose contributions due to source photons, x rays, and bremsstrahlung; source {beta}{sup -}, Auger electrons, and internal conversion electrons; and water collisional kerma were scored. To determine if conclusions obtained for electronic equilibrium conditions and electron dose contribution to total dose for the representative spherical sources could be applied to actual sources, the {sup 192}Ir mHDR-v2 source model (Nucletron B.V., Veenendaal, The Netherlands) was simulated for comparison to spherical source results and to published data. Results: Electronic equilibrium within 1% is reached for {sup 60}Co, {sup 137}Cs, {sup 192}Ir, and {sup 169}Yb at distances greater than 7, 3.5, 2, and 1 mm from the source center, respectively, in agreement with other published studies. At 1 mm from the source center, the electron contributions to total dose are 1.9% and 9.4% for {sup 60}Co and {sup 192}Ir, respectively. Electron emissions become important (i.e., >0.5%) within 3.3 mm of {sup 60}Co and 1.7 mm of {sup 192}Ir sources, yet are negligible over all distances for {sup 137}Cs and {sup 169}Yb. Electronic equilibrium conditions along the transversal source axis for the mHDR-v2 source are comparable to those of the spherical sources while electron dose to total dose contribution are quite different. Conclusions: Electronic equilibrium conditions obtained for spherical sources could be generalized to actual sources while electron contribution to total dose depends strongly on source dimensions, material composition, and electron spectra.

  5. A revised dosimetric characterization of the model S700 electronic brachytherapy source containing an anode-centering plastic insert and other components not included in the 2006 model

    Energy Technology Data Exchange (ETDEWEB)

    Hiatt, Jessica R. [Department of Radiation Oncology, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, Rhode Island 02903 (United States); Davis, Stephen D. [Department of Medical Physics, McGill University Health Centre, Montreal, Quebec H3G 1A4 (Canada); Rivard, Mark J., E-mail: mark.j.rivard@gmail.com [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States)

    2015-06-15

    Purpose: The model S700 Axxent electronic brachytherapy source by Xoft, Inc., was characterized by Rivard et al. in 2006. Since then, the source design was modified to include a new insert at the source tip. Current study objectives were to establish an accurate source model for simulation purposes, dosimetrically characterize the new source and obtain its TG-43 brachytherapy dosimetry parameters, and determine dose differences between the original simulation model and the current model S700 source design. Methods: Design information from measurements of dissected model S700 sources and from vendor-supplied CAD drawings was used to aid establishment of an updated Monte Carlo source model, which included the complex-shaped plastic source-centering insert intended to promote water flow for cooling the source anode. These data were used to create a model for subsequent radiation transport simulations in a water phantom. Compared to the 2006 simulation geometry, the influence of volume averaging close to the source was substantially reduced. A track-length estimator was used to evaluate collision kerma as a function of radial distance and polar angle for determination of TG-43 dosimetry parameters. Results for the 50 kV source were determined every 0.1 cm from 0.3 to 15 cm and every 1° from 0° to 180°. Photon spectra in water with 0.1 keV resolution were also obtained from 0.5 to 15 cm and polar angles from 0° to 165°. Simulations were run for 10{sup 10} histories, resulting in statistical uncertainties on the transverse plane of 0.04% at r = 1 cm and 0.06% at r = 5 cm. Results: The dose-rate distribution ratio for the model S700 source as compared to the 2006 model exceeded unity by more than 5% for roughly one quarter of the solid angle surrounding the source, i.e., θ ≥ 120°. The radial dose function diminished in a similar manner as for an {sup 125}I seed, with values of 1.434, 0.636, 0.283, and 0.0975 at 0.5, 2, 5, and 10 cm, respectively. The radial dose

  6. Incorporation of Electronic Brachytherapy for Skin Cancer into a Community Dermatology Practice

    OpenAIRE

    Doggett, Stephen; Willoughby, Mark; Willoughby, Cole; Mafong, Erick; Han, Amy

    2015-01-01

    Objective: The introduction of an electronic brachytherapy delivery system into an existing general dermatology practice is described. Radiobiologic rational for the dose fractionation schedule is detailed. Design: A miniaturized 50keV x-ray tube and delivery system are United States Food and Drug Administration cleared for nonmelanoma skin cancer. The device is introduced into an existing multi-physician dermatology practice in a standard unshielded treatment room. Setting: A multi-site, mul...

  7. SU-E-T-447: Electronic Brachytherapy (EBT) Treatment of Cervical Cancer - First Clinical Experience

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D; Johnson, M; Thompson, J; Ahmad, S [University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma (United States); Chan, L; Hausen, H [Xoft Inc., San Jose, CA (United States)

    2014-06-01

    Purpose: To study the first trial patient in which an electronic brachytherapy (EBT) x-ray source is utilized for treatment of cervical cancer. Methods: During patient treatment, a miniaturized x-ray source was used in combination with a customized titanium tandem and ovoid applicator set. The semi-specialized source was modeled with formalisms outlined by AAMP Task Group 43. Multiple models were used to compensate for variable attenuation conditions as a function of source positions. Varian Brachyvision treatment planning software was utilized on CT data sets for dose calculations prior to treatment delivery. The dose was prescribed to “point A” as defined by American Brachytherapy society. Additional treatments plans were created from those clinically utilized in patient care and were recalculated for an existing Ir-192 source model. Dose volume histograms (DVH) and point dose calculations were compared between the modalities for the clinical condition present in patients treated with EBT. Results: Clinical treatment times, though longer than those typically experienced by Ir-192 users, were manageable. Instantaneous dose rates at personal positions within the treatment vault were lower than those measured during intra operative radiation therapy and breast EBT treatments. Due to lower average photon energy in EBT, dose gradients within the treatment plans were as expected steeper than those observed in Ir-192 based brachytherapy. DVH comparisons between Ir-192 and EBT treatments showed an expected decrease in the integral dose to normal tissues of interest for EBT. In comparing plans created for EBT delivery with those calculated for Ir-192, average dose values for EBT were more than 4%, 11%, and 9% lower at predefined bladder, rectum and “point B” positions, respectively. Conclusion: For the first time, we have demonstrated that the utilizing electronic brachytherapy system for tandem and ovoid based treatment of cancer of the cervix is feasible, and

  8. SU-E-P-05: Electronic Brachytherapy: A Physics Perspective On Field Implementation

    Energy Technology Data Exchange (ETDEWEB)

    Pai, S; Ayyalasomayajula, S; Lee, S [iCAD Inc., Los Gatos, CA (United States)

    2015-06-15

    Purpose: We want to summarize our experience implementing a successful program of electronic brachytherapy at several dermatology clinics with the help of a cloud based software to help us define the key program parameters and capture physics QA aspects. Optimally developed software helps the physicist in peer review and qualify the physical parameters. Methods: Using the XOFT™ Axxent™ electronic brachytherapy system in conjunction with a cloud-based software, a process was setup to capture and record treatments. It was implemented initially at about 10 sites in California. For dosimetric purposes, the software facilitated storage of the physics parameters of surface applicators used in treatment and other source calibration parameters. In addition, the patient prescription, pathology and other setup considerations were input by radiation oncologist and the therapist. This facilitated physics planning of the treatment parameters and also independent check of the dwell time. From 2013–2014, nearly1500 such calculation were completed by a group of physicists. A total of 800 patients with multiple lesions have been treated successfully during this period. The treatment log files have been uploaded and documented in the software which facilitated physics peer review of treatments per the standards in place by AAPM and ACR. Results: The program model was implemented successfully at multiple sites. The cloud based software allowed for proper peer review and compliance of the program at 10 clinical sites. Dosimtery was done on 800 patients and executed in a timely fashion to suit the clinical needs. Accumulated physics data in the software from the clinics allows for robust analysis and future development. Conclusion: Electronic brachytherapy implementation experience from a quality assurance perspective was greatly enhanced by using a cloud based software. The comprehensive database will pave the way for future developments to yield superior physics outcomes.

  9. SU-E-T-547: Rotating Shield Brachytherapy (RSBT) for Cervical Cancer.

    Science.gov (United States)

    Yang, W; Kim, Y; Liu, Y; Wu, X; Flynn, R

    2012-06-01

    To assess rotating shield brachytherapy (RSBT) delivered with the electronic brachytherapy (eBT) source comparing to intracavitary (IC) and intracavitary plus supplemental interstitial brachytherapy (IC+IS BT) delivered with conventional isotope radiation source. IC, IC+IS and RSBT plan was simulated for 5 patients with advanced cervical cancer (>40cc). One BT plan for each patient (fraction 1) guided by magnetic resonance imaging (MRI) was used in our treatment planning system (TPS). A bio- and MRI-compatible polycarbonate (Makrolon Rx3158) intrauterine applicator was simulated for IC and RSBT, and the vienna applicator was simulated for IC+IS BT. 192Ir was used as the radiation source of IC and IC+IS BT; Xoft AxxentTM eBT source was used for RSBT. A 0.5 mm thick tungsten shield was used for RS-BT with different azimuthal and zenith angles. The total dose for each plan was escalated as the external beam radiation therapy (EBRT) plus BT times fraction number (5 in our case). RSBT and IC+IS BT had higher dose conformity in terms of D90 than IC BT for all the patients. The advantage of RSBT over IC+IS BT was dependent on the shield emission angle, tumor shape and tandem applicator location. The delivery time of RSBT was increased as finer emission angle was selected. RSBT is a less-invasive potential alternative to conventional IC and IC+IS BT for treating bulky (>40cc) cervical cancer. RSBT can provide better treatment outcome with clinically acceptable increased delivery time if proper emission angle is selected based on the tumor shape and tandem applicator location. supported in part by NSF grants CCF-0830402 and CCF-0844765; and the NIH grant K25-CA123112, and American Cancer Society seed grant (IRG-77-004-31). © 2012 American Association of Physicists in Medicine.

  10. The initial experience of electronic brachytherapy for the treatment of non-melanoma skin cancer

    Directory of Open Access Journals (Sweden)

    Bhatnagar Ajay

    2010-09-01

    Full Text Available Abstract Background Millions of people are diagnosed with non-melanoma skin cancers (NMSC worldwide each year. While surgical approaches are the standard treatment, some patients are appropriate candidates for radiation therapy for NMSC. High dose rate (HDR brachytherapy using surface applicators has shown efficacy in the treatment of NMSC and shortens the radiation treatment schedule by using a condensed hypofractionated approach. An electronic brachytherapy (EBT system permits treatment of NMSC without the use of a radioactive isotope. Methods Data were collected retrospectively from patients treated from July 2009 through March 2010. Pre-treatment biopsy was performed to confirm a malignant cutaneous diagnosis. A CT scan was performed to assess lesion depth for treatment planning, and an appropriate size of surface applicator was selected to provide an acceptable margin. An HDR EBT system delivered a dose of 40.0 Gy in eight fractions twice weekly with 48 hours between fractions, prescribed to a depth of 3-7 mm. Treatment feasibility, acute safety, efficacy outcomes, and cosmetic results were assessed. Results Thirty-seven patients (mean age 72.5 years with 44 cutaneous malignancies were treated. Of 44 lesions treated, 39 (89% were T1, 1 (2% Tis, 1 (2% T2, and 3 (7% lesions were recurrent. Lesion locations included the nose for 16 lesions (36.4%, ear 5 (11%, scalp 5 (11%, face 14 (32%, and an extremity for 4 (9%. Median follow-up was 4.1 months. No severe toxicities occurred. Cosmesis ratings were good to excellent for 100% of the lesions at follow-up. Conclusions The early outcomes of EBT for the treatment of NMSC appear to show acceptable acute safety and favorable cosmetic outcomes. Using a hypofractionated approach, EBT provides a convenient treatment schedule.

  11. Rapid emission angle selection for rotating-shield brachytherapy

    Science.gov (United States)

    Liu, Yunlong; Flynn, Ryan T.; Yang, Wenjun; Kim, Yusung; Bhatia, Sudershan K.; Sun, Wenqing; Wu, Xiaodong

    2013-01-01

    Purpose: The authors present a rapid emission angle selection (REAS) method that enables the efficient selection of the azimuthal shield angle for rotating shield brachytherapy (RSBT). The REAS method produces a Pareto curve from which a potential RSBT user can select a treatment plan that balances the tradeoff between delivery time and tumor dose conformity. Methods: Two cervical cancer patients were considered as test cases for the REAS method. The RSBT source considered was a Xoft AxxentTM electronic brachytherapy source, partially shielded with 0.5 mm of tungsten, which traveled inside a tandem intrauterine applicator. Three anchor RSBT plans were generated for each case using dose-volume optimization, with azimuthal shield emission angles of 90°, 180°, and 270°. The REAS method converts the anchor plans to treatment plans for all possible emission angles by combining neighboring beamlets to form beamlets for larger emission angles. Treatment plans based on exhaustive dose-volume optimization (ERVO) and exhaustive surface optimization (ERSO) were also generated for both cases. Uniform dwell-time scaling was applied to all plans such that that high-risk clinical target volume D90 was maximized without violating the D2cc tolerances of the rectum, bladder, and sigmoid colon. Results: By choosing three azimuthal emission angles out of 32 potential angles, the REAS method performs about 10 times faster than the ERVO method. By setting D90 to 85–100 Gy10, the delivery times used by REAS generated plans are 21.0% and 19.5% less than exhaustive surface optimized plans used by the two clinical cases. By setting the delivery time budget to 5–25 and 10–30 min/fx, respectively, for two the cases, the D90 contributions for REAS are improved by 5.8% and 5.1% compared to the ERSO plans. The ranges used in this comparison were selected in order to keep both D90 and the delivery time within acceptable limits. Conclusions: The REAS method enables efficient RSBT

  12. Use of electronic brachytherapy to deliver postsurgical adjuvant radiation therapy for endometrial cancer: a retrospective multicenter study

    Directory of Open Access Journals (Sweden)

    William C Dooley

    2010-09-01

    Full Text Available William C Dooley1, John P Thropay2, Gary J Schreiber3, Mohamed Y Puthawala4, Steven C Lane5, James C Wurzer6, Charles E Stewart7, Gordon L Grado8, Harish G Ahuja9, Gary M Proulx101University of Oklahoma Health Sciences Center, Oklahoma City, OK; 2Beverly Oncology and Imaging Center, Montebello, CA; 3Swedish Covenant Medical Center, Chicago, IL; 4Rhode Island Hospital, Providence, RI; 5Signature Healthcare Brockton Hospital, Brockton, MA; 6AtlantiCare Regional Medical Center, Egg Harbor Township, NJ; 7St Francis Medical Center, Tulsa, OK; 8Southwest Oncology Centers, Scottsdale, AZ; 9Aspirus Regional Medical Center, Wausau, WI; 10Exeter Hospital, Exeter, NH, USABackground: This retrospective, multicenter study evaluated the feasibility and safety of high-dose rate electronic brachytherapy (EBT as a postsurgical adjuvant radiation therapy for endometrial cancer.Methods: Medical records were reviewed from 41 patients (age 40–89 years with endometrial cancer (Federation of International Gynecology and Obstetrics stages IA–IIIC treated at nine centers between April 2008 and October 2009. Treatment included intracavitary vaginal EBT alone (n = l6 at doses of 18.0–24.0 Gy in 3–4 fractions and EBT in combination with external beam radiation therapy (EBRT, n = 25 at a total radiation dose range of 40.0–80.4 Gy. Doses were prescribed to a depth of 5 mm from the applicator surface and to the upper third (n = 15 and the upper half (n = 26 of the vagina.Results: Median follow-up was 3.8 (range 0.5–12.0 months. All 41 patients received the intended dose of radiation as prescribed. Adverse events occurred in 13 of 41 patients and were mild to moderate (Grade 1–2, consisting primarily of vaginal mucositis, rectal mucosal irritation and discomfort, and temporary dysuria and diarrhea. There were no Grade 3 adverse events in the EBT-only treatment group. One patient, who was being treated with the combination of EBT and EBRT for recurrent endometrial

  13. Influences of spherical phantom heterogeneities on dosimetric charactristics of miniature electronic brachytherapy X-ray sources: Monte Carlo study.

    Science.gov (United States)

    Karimi Jashni, Hojatollah; Safigholi, Habib; Meigooni, Ali S

    2014-10-23

    Dose calculations in current brachytherapy treatment planning systems (TPS) are commonly based on TG-43U1 formalism. These TPS are obtained by superposition principle of single-source dosimetric parameters in liquid water, neglecting the effects of tissue heterogeneity. In this work, the sensitivity of the TG-43U1 based radial dose function (g(r)) of Miniature Electronic Brachytherapy X-ray Sources (MEBXS) to bone-heterogeneity was examined. To quantify the heterogeneity effects for g(r), a series of Monte Carlo (MC) based radiation transport simulations at the center of homogeneous and heterogeneous spherical phantoms were performed using the MCNP5 code. The ratio of the g(r) in the heterogeneius phantom to the uniform soft tisuue phantom as a function of the bone thickness was determined. These results indicated that for 40keV beam, the maximum ratios for thicknesses of 1cm and 2cm were 3.36 and 3.27, respectively. These values changed to 4.28 and 4.06, for 60keV beam, respectively. Introduction of 0.5cm or 1cm red marrow, into the interior of the cortical bone changed the maximum variations to, 3.54, and 3.57 for 40keV, and 4.28, and 4.25, for 60keV, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Sci-Sat AM(2): Brachy-04: Spectral and dosimetric study of the Xoft electronic brachytherapy system.

    Science.gov (United States)

    Liu, D; Reniers, B; Poon, E; Bazalova, M; Rusch, T; Verhaegen, F

    2008-07-01

    The Axxent developed by Xoft Inc. is a miniature x-ray tube capable of generating a 50 kVp x-ray spectrum with dose-rates suitable for HDR applications. Results of spectral measurements compared with Geant4 Monte Carlo simulations have been published. This study is a continuation of previous work with shifting emphasis towards dosimetric characterization of the miniature x-ray tube. Dose distributions using EBT Gafchromic films agree to within 10 % of Geant4 results. In addition, TG-43 parameters can be calculated. However, consideration should be given to the biological effectiveness of the spectrum at different depths. Spectral measurements show significant beam hardening with 1(st) HVL increasing from 0.55 to 1.20 mm Al after 11.50 mm of water filtration. This effect may be attributed to the significant loss of low energy characteristic photons. Furthermore, the degree of beam hardening is dependent of the material, with 1(st) HVLs of 1.20 and 1.03 mm Al after 11.50 mm of water and Lucite respectively. The biological effect is quantified by calculating the number of single and double strand breaks. The number of strand breaks for the 50 kVp x-ray spectrum is similar to that of I-125 radiation. © 2008 American Association of Physicists in Medicine.

  15. Electronic brachytherapy for superficial and nodular basal cell carcinoma: a report of two prospective pilot trials using different doses

    Directory of Open Access Journals (Sweden)

    Rosa Ballester-Sánchez

    2016-01-01

    Full Text Available Purpose : Basal cell carcinoma (BCC is a very common cancer in the Caucasian population. Treatment aims to eradicate the tumor with the lowest possible functional and aesthetic impact. Electronic brachytherapy (EBT is a treatment technique currently emerging. This study aims to show the outcomes of two consecutive prospective pilot clinical trials using different radiation doses of EBT with Esteya® EB system for the treatment of superficial and nodular basal cell carcinoma. Material and methods : Two prospective, single-center, non-randomized, pilot studies were conducted. Twenty patients were treated in each study with different doses. The first group (1 was treated with 36.6 Gy in 6 fractions of 6.1 Gy, and the second group (2 with 42 Gy in 6 fractions of 7 Gy. Cure rate, acute toxicity, and late toxicity related to cosmesis were analyzed in the two treatment groups. Results: In group 1, a complete response in 90% of cases was observed at the first year of follow-up, whereas in group 2, the complete response was 95%. The differences with reference to acute toxicity and the cosmetic results between the two treatment groups were not statistically significant. Conclusions : Our initial experience with Esteya® EB system to treat superficial and nodular BCC shows that a dose of 36.6 Gy and 42 Gy delivered in 6 fraction of 7 Gy achieves a 90% and 95% clinical cure rate at 1 year, respectively. Both groups had a tolerable toxicity and a very good cosmesis. The role of EBT in the treatment of BCC is still to be defined. It will probably become an established option for selected patients in the near future.

  16. Intravascular brachytherapy for peripheral vascular disease

    Directory of Open Access Journals (Sweden)

    Hagen, Anja

    2008-09-01

    Full Text Available Scientific background: Percutaneous transluminal angioplasties (PTA through balloon dilatation with or without stenting, i.e. vessel expansion through balloons with or without of implantation of small tubes, called stents, are used in the treatment of peripheral artery occlusive disease (PAOD. The intravascular vessel irradiation, called intravascular brachytherapy, promises a reduction in the rate of repeated stenosis (rate of restenosis after PTA. Research questions: The evaluation addresses questions on medical efficacy, cost-effectiveness as well as ethic, social and legal implications in the use of brachytherapy in PAOD patients. Methods: A systematic literature search was conducted in August 2007 in the most important medical electronic databases for publications beginning from 2002. The medical evaluation included randomized controlled trials (RCT. The information synthesis was performed using meta-analysis. Health economic modeling was performed with clinical assumptions derived from the meta-analysis and economical assumptions derived from the German Diagnosis Related Groups (G-DRG-2007. Results: Medical evaluation: Twelve publications about seven RCT on brachytherapy vs. no brachytherapy were included in the medical evaluation. Two RCT showed a significant reduction in the rate of restenosis at six and/or twelve months for brachytherapy vs. no brachytherapy after successful balloon dilatation, the relative risk in the meta-analysis was 0.62 (95% CI: 0.46 to 0.84. At five years, time to recurrence of restenosis was significantly delayed after brachytherapy. One RCT showed a significant reduction in the rate of restenosis at six months for brachytherapy vs. no brachytherapy after PTA with optional stenting, the relative risk in the meta-analysis was 0.76 (95% CI: 0.61 to 0.95. One RCT observed a significantly higher rate of late thrombotic occlusions after brachytherapy in the subgroup of stented patients. A single RCT for brachytherapy

  17. Brachytherapy applications and techniques

    CERN Document Server

    Devlin, Phillip M

    2015-01-01

    Written by the foremost experts in the field, this volume is a comprehensive text and practical reference on contemporary brachytherapy. The book provides detailed, site-specific information on applications and techniques of brachytherapy in the head and neck, central nervous system, breast, thorax, gastrointestinal tract, and genitourinary tract, as well as on gynecologic brachytherapy, low dose rate and high dose rate sarcoma brachytherapy, vascular brachytherapy, and pediatric applications. The book thoroughly describes and compares the four major techniques used in brachytherapy-intraca

  18. Three dimensional intensity modulated brachytherapy (IMBT): Dosimetry algorithm and inverse treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Shi Chengyu; Guo Bingqi; Cheng, Chih-Yao; Esquivel, Carlos; Eng, Tony; Papanikolaou, Niko [Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229 (United States); Department of Radiation Oncology, Oklahoma University Health Science Center, Oklahoma City, Oklahoma 73104 (United States); Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229 (United States)

    2010-07-15

    Purpose: The feasibility of intensity modulated brachytherapy (IMBT) to improve dose conformity for irregularly shaped targets has been previously investigated by researchers by means of using partially shielded sources. However, partial shielding does not fully explore the potential of IMBT. The goal of this study is to introduce the concept of three dimensional (3D) intensity modulated brachytherapy and solve two fundamental issues regarding the application of 3D IMBT treatment planning: The dose calculation algorithm and the inverse treatment planning method. Methods: A 3D IMBT treatment planning system prototype was developed using the MATLAB platform. This system consists of three major components: (1) A comprehensive IMBT source calibration method with dosimetric inputs from Monte Carlo (EGSnrc) simulations; (2) a ''modified TG-43'' (mTG-43) dose calculation formalism for IMBT dosimetry; and (3) a physical constraint based inverse IMBT treatment planning platform utilizing a simulated annealing optimization algorithm. The model S700 Axxent electronic brachytherapy source developed by Xoft, Inc. (Fremont, CA), was simulated in this application. Ten intracavitary accelerated partial breast irradiation (APBI) cases were studied. For each case, an ''isotropic plan'' with only optimized source dwell time and a fully optimized IMBT plan were generated and compared to the original plan in various dosimetric aspects, such as the plan quality, planning, and delivery time. The issue of the mechanical complexity of the IMBT applicator is not addressed in this study. Results: IMBT approaches showed superior plan quality compared to the original plans and the isotropic plans to different extents in all studied cases. An extremely difficult case with a small breast and a small distance to the ribs and skin, the IMBT plan minimized the high dose volume V{sub 200} by 16.1% and 4.8%, respectively, compared to the original and the

  19. SU-E-T-606: Optimal Emission Angle Selection in Rotating Shield Brachytherapy.

    Science.gov (United States)

    Liu, Y; Flynn, R; Yang, W; Kim, Y; Wu, X

    2012-06-01

    In this work a general method is presented that enables clinicians to rapidly select Rotating shield brachytherapy (RSBT) emission angles based on the patient-specific tradeoff between delivery time and tumor dose conformity. Cervical cancer cases are used as examples. Anchor plans with high dose conformity but infeasible delivery times are generated with a fine emission angle, with simulated annealing. The RSBT emission angle selector determines the optimal emission angle for each case by efficiently solving a globally-optimal quadratic programming problem that closely reproduces the angular distribution of beam intensities from the anchor plan. Pareto plots of the dosimetric plan quality metrics, such as D90 versus the delivery time, are generated for clinicians. In this work two cervical cancer cases were considered for verification. The RSBT system was assumed to be a Xoft AxxentTM electronic BT(eBT) source with a 0.2mm tungsten shield. The intent for each treatment plans was to maximize tumor D90 while respective the GEC-ESTRO recommended constraints on the D2cc values to OARs. Generating anchor plans with simulated annealing takes 10-20min while emission angle selection can finish within seconds. The shield sequencing algorithm also ensures the balance between D90 and delivery time. One case shows that the D90 can achieve 98.3Gy10 with emission angle 202.5 degree with 8.64min delivery, while the conventional intracavitary plan has D90 65Gy10 with 2.86min delivery. Another case shows RSBT with emission angle 67.5 degree can produce D90 108.7Gy10 with 44min, and the conventional plan uses 2.2min for D90 48.9Gy10. The RSBT emission angle selection algorithm enables the users to rapidly determine the best emission angle for a given cervical cancer case by selecting the most appropriate D90 and delivery time. RSBT may be a less invasive alternative to intracavitary and supplementary interstitial BT for the treatment of cervical cancer tumors, supported in part by

  20. Advancements in brachytherapy

    DEFF Research Database (Denmark)

    Tanderup, Kari; Ménard, Cynthia; Polgar, Csaba

    2017-01-01

    Brachytherapy is a radiotherapy modality associated with a highly focal dose distribution. Brachytherapy treats the cancer tissue from the inside, and the radiation does not travel through healthy tissue to reach the target as with external beam radiotherapy techniques. The nature of brachytherap...... in terms of controlling dose and demonstrating excellent clinical outcome. Interests in focal, hypofractionated and adaptive treatments are increasing, and brachytherapy has significant potential to develop further in these directions with current and new treatment indications....

  1. Dynamic rotating-shield brachytherapy.

    Science.gov (United States)

    Liu, Yunlong; Flynn, Ryan T; Kim, Yusung; Yang, Wenjun; Wu, Xiaodong

    2013-12-01

    To present dynamic rotating shield brachytherapy (D-RSBT), a novel form of high-dose-rate brachytherapy (HDR-BT) with electronic brachytherapy source, where the radiation shield is capable of changing emission angles during the radiation delivery process. A D-RSBT system uses two layers of independently rotating tungsten alloy shields, each with a 180° azimuthal emission angle. The D-RSBT planning is separated into two stages: anchor plan optimization and optimal sequencing. In the anchor plan optimization, anchor plans are generated by maximizing the D90 for the high-risk clinical-tumor-volume (HR-CTV) assuming a fixed azimuthal emission angle of 11.25°. In the optimal sequencing, treatment plans that most closely approximate the anchor plans under the delivery-time constraint will be efficiently computed. Treatment plans for five cervical cancer patients were generated for D-RSBT, single-shield RSBT (S-RSBT), and (192)Ir-based intracavitary brachytherapy with supplementary interstitial brachytherapy (IS + ICBT) assuming five treatment fractions. External beam radiotherapy doses of 45 Gy in 25 fractions of 1.8 Gy each were accounted for. The high-risk clinical target volume (HR-CTV) doses were escalated such that the D2cc of the rectum, sigmoid colon, or bladder reached its tolerance equivalent dose in 2 Gy fractions (EQD2 with α∕β = 3 Gy) of 75 Gy, 75 Gy, or 90 Gy, respectively. For the patients considered, IS + ICBT had an average total dwell time of 5.7 minutes∕fraction (min∕fx) assuming a 10 Ci(192)Ir source, and the average HR-CTV D90 was 78.9 Gy. In order to match the HR-CTV D90 of IS + ICBT, D-RSBT required an average of 10.1 min∕fx more delivery time, and S-RSBT required 6.7 min∕fx more. If an additional 20 min∕fx of delivery time is allowed beyond that of the IS + ICBT case, D-RSBT and S-RSBT increased the HR-CTV D90 above IS + ICBT by an average of 16.3 Gy and 9.1 Gy, respectively. For cervical cancer patients, D-RSBT can boost HR-CTV D90

  2. SU-D-210-07: The Dependence On Acoustic Velocity of Medium On the Needle Template and Electronic Grid Alignment in Ultrasound QA for Prostate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kapoor, P; Kapoor, R; Curran, B [Virginia Commonwealth University, Richmond, VA (United States); HH McGuire VA Hospital, Richmond, VA (United States)

    2015-06-15

    Purpose: To analyze the impact on acoustic velocity (AV) of two different media (water and milk) using the needle template/electronic grid alignment test. Water, easily available, makes a good material to test the alignment of the template and grid although water’s AV (1498 m/s at 25°C) is significantly different from tissue (1540 m/s). Milk, with an AV much closer (1548 m/s) to prostate tissue, may be a good substitute for water in ultrasound quality assurance testing. Methods: Tests were performed using a Hitachi ultrasound unit with a mechanical arrangement designed to position needles parallel to the transducer. In this work, two materials – distilled water and homogenized whole milk (AVs of 1498 and 1548 m/s at 25°C) were used in a phantom to test ultrasound needle/grid alignment. The images were obtained with both materials and analyzed for their placement accuracy. Results: The needle template/electronic grid alignment tests showed displacement errors between measured and calculated values. The measurements showed displacements of 2.3mm (water) and 0.4mm (milk), and 1.6mm (water) and 0.3mm (milk) at depths of 7cm and 5cm respectively from true needle positions. The calculated results showed a displacement of 2.36 mm (water); 0.435mm (milk), and 1.66mm (water) and 0.31mm (milk) at a depth of 7cm and 5cm respectively. The displacements in the X and Y directions were also calculated. At depths of 7cm and 5cm, the (ΔX,ΔY) displacements in water were (0.829mm, 2.21mm) and (0.273mm, 1.634mm) and for milk were (0.15mm, 0.44mm) and (0.05mm, 0.302mm) respectively. Conclusion: The measured and calculated values were in good agreement for all tests. They show that milk provides superior results when performing needle template and electronic grid alignment tests for ultrasound units used in prostate brachytherapy.

  3. Physics and basic parameters of brachytherapy.

    Science.gov (United States)

    Lee, E J; Weinhous, M S

    1997-06-01

    Brachytherapy (short-distance therapy) is the therapeutic process whereby radioactive sources are placed into very close proximity to target tissue. Radioactive materials were so used beginning shortly after the discovery of radium by Marie and Pierre Curie in 1898. For the purposes of brachytherapy, radioactive materials are those that emit "rays" that can cause ionization (and hence DNA damage and the destruction of target cells). The potentially useful rays include beta, gamma, and other possibilities such as neutrons. Beta rays, properly beta particles, are simply high energy electrons. Gamma rays are high energy photons (part of the electromagnetic spectrum like visible light, but with much higher energy). These particles are produced during the radioactive decay of certain isotopes. The physics of those events and the parameters that apply to the therapeutic use of the isotopes are the primary topics of this report.

  4. Rotating-shield brachytherapy for cervical cancer

    Science.gov (United States)

    Yang, Wenjun; Kim, Yusung; Wu, Xiaodong; Song, Qi; Liu, Yunlong; Bhatia, Sudershan K.; Sun, Wenqing; Flynn, Ryan T.

    2013-06-01

    In this treatment planning study, the potential benefits of a rotating shield brachytherapy (RSBT) technique based on a partially-shielded electronic brachytherapy source were assessed for treating cervical cancer. Conventional intracavitary brachytherapy (ICBT), intracavitary plus supplementary interstitial (IS+ICBT), and RSBT treatment plans for azimuthal emission angles of 180° (RSBT-180) and 45° (RSBT-45) were generated for five patients. For each patient, high-risk clinical target volume (HR-CTV) equivalent dose in 2 Gy fractions (EQD2) (α/β = 10 Gy) was escalated until bladder, rectum, or sigmoid colon tolerance EQD2 values were reached. External beam radiotherapy dose (1.8 Gy × 25) was accounted for, and brachytherapy was assumed to have been delivered in 5 fractions. IS+ICBT provided a greater HR-CTV D90 (minimum EQD2 to the hottest 90%) than ICBT. D90 was greater for RSBT-45 than IS+ICBT for all five patients, and greater for RSBT-180 than IS+ICBT for two patients. When the RSBT-45/180 plan with the lowest HR-CTV D90 that was greater than the D90 the ICBT or IS+ICBT plan was selected, the average (range) of D90 increases for RSBT over ICBT and IS+ICBT were 16.2 (6.3-27.2)and 8.5 (0.03-20.16) Gy, respectively. The average (range) treatment time increase per fraction of RSBT was 34.56 (3.68-70.41) min over ICBT and 34.59 (3.57-70.13) min over IS+ICBT. RSBT can increase D90 over ICBT and IS+ICBT without compromising organ-at-risk sparing. The D90 and treatment time improvements from RSBT depend on the patient and shield emission angle.

  5. MO-E-BRD-03: Intra-Operative Breast Brachytherapy: Is One Stop Shopping Best? [Non-invasive Image-Guided Breast Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Libby, B. [University of Virginia (United States)

    2015-06-15

    Is Non-invasive Image-Guided Breast Brachytherapy Good? – Jess Hiatt, MS Non-invasive Image-Guided Breast Brachytherapy (NIBB) is an emerging therapy for breast boost treatments as well as Accelerated Partial Breast Irradiation (APBI) using HDR surface breast brachytherapy. NIBB allows for smaller treatment volumes while maintaining optimal target coverage. Considering the real-time image-guidance and immobilization provided by the NIBB modality, minimal margins around the target tissue are necessary. Accelerated Partial Breast Irradiation in brachytherapy: is shorter better? - Dorin Todor, PhD VCU A review of balloon and strut devices will be provided together with the origins of APBI: the interstitial multi-catheter implant. A dosimetric and radiobiological perspective will help point out the evolution in breast brachytherapy, both in terms of devices and the protocols/clinical trials under which these devices are used. Improvements in imaging, delivery modalities and convenience are among the factors driving the ultrashort fractionation schedules but our understanding of both local control and toxicities associated with various treatments is lagging. A comparison between various schedules, from a radiobiological perspective, will be given together with a critical analysis of the issues. to review and understand the evolution and development of APBI using brachytherapy methods to understand the basis and limitations of radio-biological ‘equivalence’ between fractionation schedules to review commonly used and proposed fractionation schedules Intra-operative breast brachytherapy: Is one stop shopping best?- Bruce Libby, PhD. University of Virginia A review of intraoperative breast brachytherapy will be presented, including the Targit-A and other trials that have used electronic brachytherapy. More modern approaches, in which the lumpectomy procedure is integrated into an APBI workflow, will also be discussed. Learning Objectives: To review past and current

  6. Pulsed-Dose Rate Brachytherapy for the Treatment of Endometrial Cancer.

    Science.gov (United States)

    De Felice, Francesca; Caiazzo, Rossella; Benevento, Ilaria; Musio, Daniela; Rubini, Filippo; Tombolini, Vincenzo

    2017-01-01

    Endometrial cancer (EC) is the most frequent gynecologic malignancy. The aim of this review is to outline clinical practice recommendations, to suggest a technical solution, and to advise doses selection for pulsed-dose rate (PDR) brachytherapy in EC. Electronic bibliographic databases, including PubMed, clinicaltrials.gov, and the American Society of Clinical Oncology (ASCO) Meeting Library, were searched for articles in English. Clinical guidelines and systematic reviews were also considered. The appropriate therapeutic approach should consider risk factors for tumor relapse and PDR brachytherapy and have a convincing role in this multidisciplinary scenario. Performing PDR brachytherapy in EC requires robust training and experience. © 2017 S. Karger AG, Basel.

  7. A Customized Finger Brachytherapy Carrier

    OpenAIRE

    Wadhwa, Supneet Singh; Duggal, Nidhi

    2013-01-01

    In recent years, radiation therapy has been used with increasing frequency in the management of neoplasms of the head and neck region. Brachytherapy is a method of radiation treatment in which sealed radioactive sources are used to deliver the dose a short distance by interstitial (direct insertion into tissue), intracavitary (placement within a cavity) or surface application (molds). Mold brachytherapy is radiation delivered via a custom-fabricated carriers, designed to provide a more consta...

  8. MO-E-BRD-00: Breast Brachytherapy: The Phoenix of Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-06-15

    Is Non-invasive Image-Guided Breast Brachytherapy Good? – Jess Hiatt, MS Non-invasive Image-Guided Breast Brachytherapy (NIBB) is an emerging therapy for breast boost treatments as well as Accelerated Partial Breast Irradiation (APBI) using HDR surface breast brachytherapy. NIBB allows for smaller treatment volumes while maintaining optimal target coverage. Considering the real-time image-guidance and immobilization provided by the NIBB modality, minimal margins around the target tissue are necessary. Accelerated Partial Breast Irradiation in brachytherapy: is shorter better? - Dorin Todor, PhD VCU A review of balloon and strut devices will be provided together with the origins of APBI: the interstitial multi-catheter implant. A dosimetric and radiobiological perspective will help point out the evolution in breast brachytherapy, both in terms of devices and the protocols/clinical trials under which these devices are used. Improvements in imaging, delivery modalities and convenience are among the factors driving the ultrashort fractionation schedules but our understanding of both local control and toxicities associated with various treatments is lagging. A comparison between various schedules, from a radiobiological perspective, will be given together with a critical analysis of the issues. to review and understand the evolution and development of APBI using brachytherapy methods to understand the basis and limitations of radio-biological ‘equivalence’ between fractionation schedules to review commonly used and proposed fractionation schedules Intra-operative breast brachytherapy: Is one stop shopping best?- Bruce Libby, PhD. University of Virginia A review of intraoperative breast brachytherapy will be presented, including the Targit-A and other trials that have used electronic brachytherapy. More modern approaches, in which the lumpectomy procedure is integrated into an APBI workflow, will also be discussed. Learning Objectives: To review past and current

  9. MO-E-BRD-01: Is Non-Invasive Image-Guided Breast Brachytherapy Good?

    Energy Technology Data Exchange (ETDEWEB)

    Hiatt, J. [Rhode Island Hospital (United States)

    2015-06-15

    Is Non-invasive Image-Guided Breast Brachytherapy Good? – Jess Hiatt, MS Non-invasive Image-Guided Breast Brachytherapy (NIBB) is an emerging therapy for breast boost treatments as well as Accelerated Partial Breast Irradiation (APBI) using HDR surface breast brachytherapy. NIBB allows for smaller treatment volumes while maintaining optimal target coverage. Considering the real-time image-guidance and immobilization provided by the NIBB modality, minimal margins around the target tissue are necessary. Accelerated Partial Breast Irradiation in brachytherapy: is shorter better? - Dorin Todor, PhD VCU A review of balloon and strut devices will be provided together with the origins of APBI: the interstitial multi-catheter implant. A dosimetric and radiobiological perspective will help point out the evolution in breast brachytherapy, both in terms of devices and the protocols/clinical trials under which these devices are used. Improvements in imaging, delivery modalities and convenience are among the factors driving the ultrashort fractionation schedules but our understanding of both local control and toxicities associated with various treatments is lagging. A comparison between various schedules, from a radiobiological perspective, will be given together with a critical analysis of the issues. to review and understand the evolution and development of APBI using brachytherapy methods to understand the basis and limitations of radio-biological ‘equivalence’ between fractionation schedules to review commonly used and proposed fractionation schedules Intra-operative breast brachytherapy: Is one stop shopping best?- Bruce Libby, PhD. University of Virginia A review of intraoperative breast brachytherapy will be presented, including the Targit-A and other trials that have used electronic brachytherapy. More modern approaches, in which the lumpectomy procedure is integrated into an APBI workflow, will also be discussed. Learning Objectives: To review past and current

  10. MO-E-BRD-02: Accelerated Partial Breast Irradiation in Brachytherapy: Is Shorter Better?

    Energy Technology Data Exchange (ETDEWEB)

    Todor, D. [Virginia Commonwealth University (United States)

    2015-06-15

    Is Non-invasive Image-Guided Breast Brachytherapy Good? – Jess Hiatt, MS Non-invasive Image-Guided Breast Brachytherapy (NIBB) is an emerging therapy for breast boost treatments as well as Accelerated Partial Breast Irradiation (APBI) using HDR surface breast brachytherapy. NIBB allows for smaller treatment volumes while maintaining optimal target coverage. Considering the real-time image-guidance and immobilization provided by the NIBB modality, minimal margins around the target tissue are necessary. Accelerated Partial Breast Irradiation in brachytherapy: is shorter better? - Dorin Todor, PhD VCU A review of balloon and strut devices will be provided together with the origins of APBI: the interstitial multi-catheter implant. A dosimetric and radiobiological perspective will help point out the evolution in breast brachytherapy, both in terms of devices and the protocols/clinical trials under which these devices are used. Improvements in imaging, delivery modalities and convenience are among the factors driving the ultrashort fractionation schedules but our understanding of both local control and toxicities associated with various treatments is lagging. A comparison between various schedules, from a radiobiological perspective, will be given together with a critical analysis of the issues. to review and understand the evolution and development of APBI using brachytherapy methods to understand the basis and limitations of radio-biological ‘equivalence’ between fractionation schedules to review commonly used and proposed fractionation schedules Intra-operative breast brachytherapy: Is one stop shopping best?- Bruce Libby, PhD. University of Virginia A review of intraoperative breast brachytherapy will be presented, including the Targit-A and other trials that have used electronic brachytherapy. More modern approaches, in which the lumpectomy procedure is integrated into an APBI workflow, will also be discussed. Learning Objectives: To review past and current

  11. Multihelix rotating shield brachytherapy for cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Dadkhah, Hossein [Department of Biomedical Engineering, University of Iowa, 1402 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa 52242 (United States); Kim, Yusung; Flynn, Ryan T., E-mail: ryan-flynn@uiowa.edu [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Wu, Xiaodong [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 and Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa 52242 (United States)

    2015-11-15

    Purpose: To present a novel brachytherapy technique, called multihelix rotating shield brachytherapy (H-RSBT), for the precise angular and linear positioning of a partial shield in a curved applicator. H-RSBT mechanically enables the dose delivery using only linear translational motion of the radiation source/shield combination. The previously proposed approach of serial rotating shield brachytherapy (S-RSBT), in which the partial shield is rotated to several angular positions at each source dwell position [W. Yang et al., “Rotating-shield brachytherapy for cervical cancer,” Phys. Med. Biol. 58, 3931–3941 (2013)], is mechanically challenging to implement in a curved applicator, and H-RSBT is proposed as a feasible solution. Methods: A Henschke-type applicator, designed for an electronic brachytherapy source (Xoft Axxent™) and a 0.5 mm thick tungsten partial shield with 180° or 45° azimuthal emission angles and 116° asymmetric zenith angle, is proposed. The interior wall of the applicator contains six evenly spaced helical keyways that rigidly define the emission direction of the partial radiation shield as a function of depth in the applicator. The shield contains three uniformly distributed protruding keys on its exterior wall and is attached to the source such that it rotates freely, thus longitudinal translational motion of the source is transferred to rotational motion of the shield. S-RSBT and H-RSBT treatment plans with 180° and 45° azimuthal emission angles were generated for five cervical cancer patients with a diverse range of high-risk target volume (HR-CTV) shapes and applicator positions. For each patient, the total number of emission angles was held nearly constant for S-RSBT and H-RSBT by using dwell positions separated by 5 and 1.7 mm, respectively, and emission directions separated by 22.5° and 60°, respectively. Treatment delivery time and tumor coverage (D{sub 90} of HR-CTV) were the two metrics used as the basis for evaluation and

  12. Assessment of effective dose to staff in brachytherapy.

    Science.gov (United States)

    Faulkner, K; James, H V; Chapple, C L; Rawlings, D J

    1996-11-01

    The aim of this paper is to investigate the problem of monitoring effective dose to hospital staff who are involved in the treatment of tumors using sealed sources placed inside the body (brachytherapy). In addition, the use of an unsealed source to treat the thyroid was also considered. Radiation distributions produced by both sealed sources commonly used in brachytherapy (192I, 137Cs, 226Ra) and an unsealed source used in the treatment of the thyroid (131I) were used to irradiate a Rando phantom. The brachytherapy treatments of esophageal and gynecological carcinoma were simulated. The Rando phantom was loaded with lithium fluoride thermoluminescent dosimeters at positions corresponding to a number of radiosensitive organs. Film badges and electronic personal dosimeters were attached to the Rando phantom at various anatomical sites. The Rando phantom was positioned adjacent to the patient at an angle of 90 degrees to the longitudinal axis of the patient. Irradiations were performed with and without a portable lead screen used on the radiotherapy wards. Effective dose was estimated for each simulated radiotherapy treatment and compared with the personal monitor readings. The data were used as a basis for the provision of advice on the wearing of the film badge dosimeters and the design of portable lead screens. The data also permitted a comparison between the two types of dosimeter when used for personal monitoring in brachytherapy.

  13. Evaluation of resins for use in brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Luiz Claudio F.M. Garcia; Ferraz, Wilmar Barbosa; Chrcanovic, Bruno Ramos; Santos, Ana Maria M., E-mail: ferrazw@cdtn.b, E-mail: amms@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Brachytherapy is an advanced cancer treatment where radioactive seeds or sources are placed near or directly into the tumor thus reducing the radiation exposure in the surrounding healthy tissues. Prostate cancer can be treated with interstitial brachytherapy in initial stage of the disease in which tiny radioactive seeds with cylindrical geometry are used. Several kinds of seeds have been developed in order to obtain a better dose distribution around them and with a lower cost manufacturing. These seeds consist of an encapsulation, a radionuclide carrier, and X-ray marker. Among the materials that have potential for innovation in the construction of seeds, biocompatible resins appear as an important option. In this paper, we present some characterization results with Fourier transform infrared spectroscopic (FTIR) and ultraviolet-visible spectroscopy (UV-vis) performed on two types of resins in which curing temperatures for each one were varied as also the results of coatings with these resins under titanium substrates. Interactions of these resins in contact with the simulated body fluid were evaluated by atomic force microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. (author)

  14. Brachytherapy volume visualization

    Science.gov (United States)

    Persons, Timothy M.; Webber, Richard L.; Hemler, Paul F.; Bettermann, Wolfram; Bourland, J. Daniel

    2000-04-01

    Conventional localization schemes for brachytherapy seed implants using biplane or stereoscopic projection radio- graphs can suffer form scaling distortions and poor visibility of implanted seeds, resulting in compromised source tracking and dosimetric inaccuracies. This paper proposes an alternative method for improving the visualization and thus, localization, of radiotherapy implants by synthesizing, form as few as two radiographic projections, a 3D image free of divergence artifacts. The result produces more accurate seed localization leading to improved dosimetric accuracy. Two alternative approaches are compared. The first uses orthogonal merging. The second employs the technique of tuned-aperture computed tomography (TACT), whereby 3D reconstruction is performed by shifting and adding of well-sampled projections relative to a fiducial reference system. Phantom results using nonlinear visualization methods demonstrate the applicability of localizing individual seeds for both approaches. Geometric errors are eliminated by a calibration scheme derived from the fiducial pattern that is imaged concurrently with the subject. Both merging and TACT approaches enhance seed localization by improving visualization of the seed distribution over biplanar radiographs. Unlike current methods, both alternatives demonstrate continuos one-to-one source tracking in 3D, although elimination of scaling artifacts requires more than two projections when using the merging method.

  15. Brachytherapy in Gynecologic Cancers: Why Is It Underused?

    Science.gov (United States)

    Han, Kathy; Viswanathan, Akila N

    2016-04-01

    Despite its established efficacy, brachytherapy is underused in the management of cervical and vaginal cancers in some parts of the world. Possible reasons for the underutilization of brachytherapy include the adoption of less invasive techniques, such as intensity-modulated radiotherapy; reimbursement policies favoring these techniques over brachytherapy; poor physician or patient access to brachytherapy; inadequate maintenance of brachytherapy skills among practicing radiation oncologists; transitioning to high-dose-rate (HDR) brachytherapy with increased time requirements; and insufficient training of radiation oncology residents.

  16. In vivo dosimetry in brachytherapy

    DEFF Research Database (Denmark)

    Tanderup, Kari; Beddar, Sam; Andersen, Claus Erik;

    2013-01-01

    In vivo dosimetry (IVD) has been used in brachytherapy (BT) for decades with a number of different detectors and measurement technologies. However, IVD in BT has been subject to certain difficulties and complexities, in particular due to challenges of the high-gradient BT dose distribution and th...

  17. Epoxy resins used to seal brachytherapy seed

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Natalia Carolina Camargos; Ferraz, Wilmar Barbosa; Reis, Sergio Carneiro dos; Santos, Ana Maria Matildes dos, E-mail: nccf@cdtn.br, E-mail: ferrazw@cdtn.br, E-mail: reissc@cdtn.br, E-mail: amms@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, BH (Brazil)

    2013-07-01

    Prostate cancer treatment with brachytherapy is recommended for patients with cancer at an early stage. In this treatment, small radioactive seeds are implanted directly in the prostate gland. These seeds are composed at least of one radionuclide carrier and an X-ray marker enclosed within a metallic tube usually sealed by laser process. This process is expensive and, furthermore, it can provoke a partial volatilization of the radionuclide and change the isotropy in dose distribution around the seed. In this paper, we present a new sealing process using epoxy resin. Three kinds of resins were utilized and characterized by scanning electron microscopy (SEM), energy dispersive X ray (EDS) and by differential scanning calorimetry (DSC) after immersion in simulated body fluid (SBF) and in sodium iodine solution (NaI). The sealing process showed excellent potential to replace the sealing laser usually employed. (author)

  18. SU-E-T-552: Monte Carlo Calculation of Correction Factors for a Free-Air Ionization Chamber in Support of a National Air-Kerma Standard for Electronic Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mille, M; Bergstrom, P [National Institute of Standards and Technology, Gaithersburg, MD (United States)

    2015-06-15

    Purpose: To use Monte Carlo radiation transport methods to calculate correction factors for a free-air ionization chamber in support of a national air-kerma standard for low-energy, miniature x-ray sources used for electronic brachytherapy (eBx). Methods: The NIST is establishing a calibration service for well-type ionization chambers used to characterize the strength of eBx sources prior to clinical use. The calibration approach involves establishing the well-chamber’s response to an eBx source whose air-kerma rate at a 50 cm distance is determined through a primary measurement performed using the Lamperti free-air ionization chamber. However, the free-air chamber measurements of charge or current can only be related to the reference air-kerma standard after applying several corrections, some of which are best determined via Monte Carlo simulation. To this end, a detailed geometric model of the Lamperti chamber was developed in the EGSnrc code based on the engineering drawings of the instrument. The egs-fac user code in EGSnrc was then used to calculate energy-dependent correction factors which account for missing or undesired ionization arising from effects such as: (1) attenuation and scatter of the x-rays in air; (2) primary electrons escaping the charge collection region; (3) lack of charged particle equilibrium; (4) atomic fluorescence and bremsstrahlung radiation. Results: Energy-dependent correction factors were calculated assuming a monoenergetic point source with the photon energy ranging from 2 keV to 60 keV in 2 keV increments. Sufficient photon histories were simulated so that the Monte Carlo statistical uncertainty of the correction factors was less than 0.01%. The correction factors for a specific eBx source will be determined by integrating these tabulated results over its measured x-ray spectrum. Conclusion: The correction factors calculated in this work are important for establishing a national standard for eBx which will help ensure that dose

  19. Brachytherapy in the Management of Uveal Melanomas

    Directory of Open Access Journals (Sweden)

    Samuray Tuncer

    2014-09-01

    Full Text Available Uveal melanoma is the most common intraocular tumor in adults. Clinical studies have shown similar patient survival rates after treatment of medium-sized melanomas when comparing plaque brachytherapy with radioactive iodine-125 versus enucleation. This finding further emphasizes the importance of this globe-sparing treatment. Brachytherapy is a special local radiotherapy technique that aims to deliver high-dose radiation directly to the tumor by sparing the periocular structures. Brachytherapy is still the most widely used treatment for uveal melanoma. Iodine-125 and ruthenium-106 are the most common radioisotopes used in brachytherapy. After brachytherapy, sight-threatening complications occur unavoidably in many patients. Brachytherapy is mostly associated with long-term complications. Radiation retinopathy and cataract formation are the most common treatment-related complications. Brachytherapy provides local tumor control (ocular salvage in about 90% of patients. Adjunctive transpupillary thermotherapy (sandwich therapy improves the control rate of local tumors to 97%. About 10% of patients treated with brachytherapy subsequently require enucleation because of local tumor recurrence or neovascular glaucoma at 5 years of follow-up. Metastatic disease occurs in 10% of patients with medium-sized melanoma at 5-year follow-up. This rate increases to 55% at 10-year follow-up in patients with large melanomas (thickness >8 mm. Thus, it is very important to inform the patients under the light of these data prior to brachytherapy. (Turk J Ophthalmol 2014; 44: Supplement 43-8

  20. Afterloading: The Technique That Rescued Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Aronowitz, Jesse N., E-mail: jesse.aronowitz@umassmemorial.org

    2015-07-01

    Although brachytherapy had been established as a highly effective modality for the treatment of cancer, its application was threatened by mid-20th century due to appreciation of the radiation hazard to health care workers. This review examines how the introduction of afterloading eliminated exposure and ushered in a brachytherapy renaissance.

  1. Intraoperative HDR Brachytherapy: Present and Future

    NARCIS (Netherlands)

    I.-K.K. Kolkman-Deurloo (Inger-Karina)

    2007-01-01

    textabstractRadiotherapy is one of the most effective modalities in cancer treatment, and can be applied either by external beam radiotherapy or by brachytherapy. Brachytherapy is a treatment modality in which tumors are irradiated by positioning radioactive sources very close to or in the tumor

  2. Intraoperative HDR Brachytherapy: Present and Future

    NARCIS (Netherlands)

    I.-K.K. Kolkman-Deurloo (Inger-Karina)

    2007-01-01

    textabstractRadiotherapy is one of the most effective modalities in cancer treatment, and can be applied either by external beam radiotherapy or by brachytherapy. Brachytherapy is a treatment modality in which tumors are irradiated by positioning radioactive sources very close to or in the tumor vol

  3. Paddle-based rotating-shield brachytherapy

    Science.gov (United States)

    Liu, Yunlong; Flynn, Ryan T.; Kim, Yusung; Dadkhah, Hossein; Bhatia, Sudershan K.; Buatti, John M.; Xu, Weiyu; Wu, Xiaodong

    2015-01-01

    Purpose: The authors present a novel paddle-based rotating-shield brachytherapy (P-RSBT) method, whose radiation-attenuating shields are formed with a multileaf collimator (MLC), consisting of retractable paddles, to achieve intensity modulation in high-dose-rate brachytherapy. Methods: Five cervical cancer patients using an intrauterine tandem applicator were considered to assess the potential benefit of the P-RSBT method. The P-RSBT source used was a 50 kV electronic brachytherapy source (Xoft Axxent™). The paddles can be retracted independently to form multiple emission windows around the source for radiation delivery. The MLC was assumed to be rotatable. P-RSBT treatment plans were generated using the asymmetric dose–volume optimization with smoothness control method [Liu et al., Med. Phys. 41(11), 111709 (11pp.) (2014)] with a delivery time constraint, different paddle sizes, and different rotation strides. The number of treatment fractions (fx) was assumed to be five. As brachytherapy is delivered as a boost for cervical cancer, the dose distribution for each case includes the dose from external beam radiotherapy as well, which is 45 Gy in 25 fx. The high-risk clinical target volume (HR-CTV) doses were escalated until the minimum dose to the hottest 2 cm3 (D2cm3) of either the rectum, sigmoid colon, or bladder reached their tolerance doses of 75, 75, and 90 Gy3, respectively, expressed as equivalent doses in 2 Gy fractions (EQD2 with α/β = 3 Gy). Results: P-RSBT outperformed the two other RSBT delivery techniques, single-shield RSBT (S-RSBT) and dynamic-shield RSBT (D-RSBT), with a properly selected paddle size. If the paddle size was angled at 60°, the average D90 increases for the delivery plans by P-RSBT on the five cases, compared to S-RSBT, were 2.2, 8.3, 12.6, 11.9, and 9.1 Gy10, respectively, with delivery times of 10, 15, 20, 25, and 30 min/fx. The increases in HR-CTV D90, compared to D-RSBT, were 16.6, 12.9, 7.2, 3.7, and 1.7 Gy10

  4. Paddle-based rotating-shield brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yunlong; Xu, Weiyu [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 (United States); Flynn, Ryan T.; Kim, Yusung; Bhatia, Sudershan K.; Buatti, John M. [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Dadkhah, Hossein [Department of Biomedical Engineering, University of Iowa, 1402 Seamans Center, Iowa City, Iowa 52242 (United States); Wu, Xiaodong, E-mail: xiaodong-wu@uiowa.edu [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 and Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States)

    2015-10-15

    Purpose: The authors present a novel paddle-based rotating-shield brachytherapy (P-RSBT) method, whose radiation-attenuating shields are formed with a multileaf collimator (MLC), consisting of retractable paddles, to achieve intensity modulation in high-dose-rate brachytherapy. Methods: Five cervical cancer patients using an intrauterine tandem applicator were considered to assess the potential benefit of the P-RSBT method. The P-RSBT source used was a 50 kV electronic brachytherapy source (Xoft Axxent™). The paddles can be retracted independently to form multiple emission windows around the source for radiation delivery. The MLC was assumed to be rotatable. P-RSBT treatment plans were generated using the asymmetric dose–volume optimization with smoothness control method [Liu et al., Med. Phys. 41(11), 111709 (11pp.) (2014)] with a delivery time constraint, different paddle sizes, and different rotation strides. The number of treatment fractions (fx) was assumed to be five. As brachytherapy is delivered as a boost for cervical cancer, the dose distribution for each case includes the dose from external beam radiotherapy as well, which is 45 Gy in 25 fx. The high-risk clinical target volume (HR-CTV) doses were escalated until the minimum dose to the hottest 2 cm{sup 3} (D{sub 2cm{sup 3}}) of either the rectum, sigmoid colon, or bladder reached their tolerance doses of 75, 75, and 90 Gy{sub 3}, respectively, expressed as equivalent doses in 2 Gy fractions (EQD2 with α/β = 3 Gy). Results: P-RSBT outperformed the two other RSBT delivery techniques, single-shield RSBT (S-RSBT) and dynamic-shield RSBT (D-RSBT), with a properly selected paddle size. If the paddle size was angled at 60°, the average D{sub 90} increases for the delivery plans by P-RSBT on the five cases, compared to S-RSBT, were 2.2, 8.3, 12.6, 11.9, and 9.1 Gy{sub 10}, respectively, with delivery times of 10, 15, 20, 25, and 30 min/fx. The increases in HR-CTV D{sub 90}, compared to D-RSBT, were 16

  5. Dosimetry for the brachytherapy; Dosimetrie fuer die Brachytherapie

    Energy Technology Data Exchange (ETDEWEB)

    Ankerhold, Ulrike [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany). Fachbereich ' Dosimetrie fuer Strahlentherapie und Roentgendiagnostik' ; Schneider, Thorsten [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany). Arbeitsgruppe ' Brachytherapie'

    2013-06-15

    The authors describe the calibration of high-dose-rate {sup 192}Ir sources for the use in brachytherapy by means of the air-kerma power, which is determined in the PTB by means of an ionization chamber. For this a primary normal for the representation of the water energy dose was constructed. Furthermore the representation of the reference air-kerma rate for low-dose-rate sources in the PTB by means of a large-volume parallel-plate extrapolation chamber is described. (HSI)

  6. Comprehensive brachytherapy physical and clinical aspects

    CERN Document Server

    Baltas, Dimos; Meigooni, Ali S; Hoskin, Peter J

    2013-01-01

    Modern brachytherapy is one of the most important oncological treatment modalities requiring an integrated approach that utilizes new technologies, advanced clinical imaging facilities, and a thorough understanding of the radiobiological effects on different tissues, the principles of physics, dosimetry techniques and protocols, and clinical expertise. A complete overview of the field, Comprehensive Brachytherapy: Physical and Clinical Aspects is a landmark publication, presenting a detailed account of the underlying physics, design, and implementation of the techniques, along with practical guidance for practitioners. Bridging the gap between research and application, this single source brings together the technological basis, radiation dosimetry, quality assurance, and fundamentals of brachytherapy. In addition, it presents discussion of the most recent clinical practice in brachytherapy including prostate, gynecology, breast, and other clinical treatment sites. Along with exploring new clinical protocols, ...

  7. Survival of patients with advanced pancreatic cancer after iodine125 seeds implantation brachytherapy

    Science.gov (United States)

    Han, Quanli; Deng, Muhong; Lv, Yao; Dai, Guanghai

    2017-01-01

    Abstract Background: Brachytherapy with iodine125-labeled seeds (125I-seeds) implantation is increasingly being used to treat tumors because of its positional precision, minimal invasion, least damage to noncancerous tissue due to slow and continuous release of radioactivity and facilitation with modern medical imaging technologies. This study evaluates the survival and pain relief outcomes of the 125I-seeds implantation brachytherapy in advanced pancreatic cancer patients. Methods: Literature search was carried out in multiple electronic databases (Google Scholar, Embase, Medline/PubMed, and Ovid SP) and studies reporting I125 seeds implantation brachytherapy in pancreatic cancer patients with unresectable tumor were selected by following predetermined eligibility criteria. Random effects meta-analysis was performed to achieve inverse variance weighted effect size of the overall survival rate after the intervention. Sensitivity and subgroups analyses were also carried out. Results: Twenty-three studies (824 patients’ data) were included in the meta-analysis. 125I-seeds implantation brachytherapy alone was associated with 8.98 [95% confidence interval (CI): 6.94, 11.03] months (P < 0.00001) overall survival with 1-year survival of 25.7 ± 9.3% (mean ± standard deviation; SD) and 2-year survival was 17.9 ± 8.6% (mean ± SD). In stage IV pancreatic cancer patients, overall survival was 7.13 [95% CI: 4.75, 9.51] months (P < 0.00001). In patients treated with 125I-seeds implantation along with 1 or more therapies, overall survival was 11.75 [95% CI: 9.84, 13.65] months (P < 0.00001) with 1-year survival of 47.4 ± 22.75% (mean ± SD) and 2-year survival was 16.97 ± 3.1% (mean ± SD). 125I-seeds brachytherapy was associated with relief of pain in 79.7 ± 9.9% (mean ± SD) of the patients. Conclusions: Survival of pancreatic cancer patients after 125I-seeds implantation brachytherapy is found to be 9 months

  8. 10 CFR 35.2406 - Records of brachytherapy source accountability.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Records of brachytherapy source accountability. 35.2406... Records of brachytherapy source accountability. (a) A licensee shall maintain a record of brachytherapy source accountability required by § 35.406 for 3 years. (b) For temporary implants, the record...

  9. 10 CFR 35.406 - Brachytherapy sources accountability.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Brachytherapy sources accountability. 35.406 Section 35....406 Brachytherapy sources accountability. (a) A licensee shall maintain accountability at all times... area. (c) A licensee shall maintain a record of the brachytherapy source accountability in...

  10. Interstitial hyperthermia in combination with brachytherapy.

    Science.gov (United States)

    Coughlin, C T; Douple, E B; Strohbehn, J W; Eaton, W L; Trembly, B S; Wong, T Z

    1983-07-01

    Flexible coaxial cables were modified to serve as microwave antennas operating at a frequency of 915 MHz. These antennas were inserted into nylon afterloading tubes that had been implanted in tumors using conventional interstitial implantation techniques for iridium-192 seed brachytherapy. The tumor volume was heated to 42-45 degrees C within 15 minutes and heating was continued for a total of 1 hour per treatment. Immediately following a conventional brachytherapy dose and removal of the iridium seeds the tumors were heated again in a second treatment. This interstitial technique for delivering local hyperthermia should be compatible with most brachytherapy methods. The technique has proved so far to be practical and without complications. Temperature distributions obtained in tissue phantoms and a patient are described.

  11. Study of encapsulated {sup 170}Tm sources for their potential use in brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Ballester, Facundo; Granero, Domingo; Perez-Calatayud, Jose; Venselaar, Jack L. M.; Rivard, Mark J. [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, E-46100 Burjassot (Spain) and IFIC, CSIC, University of Valencia, E-46100 Burjassot (Spain); Department of Radiation Oncology, ERESA, Hospital General Universitario, E-46014 Valencia (Spain); Department of Radiation Oncology, La Fe University Hospital, E-46009 Valencia (Spain); Department of Medical Physics, Instituut Verbeeten, Tilburg 5000LA (Netherlands); Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States)

    2010-04-15

    Purpose: High dose-rate (HDR) brachytherapy is currently performed with {sup 192}Ir sources, and {sup 60}Co has returned recently into clinical use as a source for this kind of cancer treatment. Both radionuclides have mean photon energies high enough to require specific shielded treatment rooms. In recent years, {sup 169}Yb has been explored as an alternative for HDR-brachytherapy implants. Although it has mean photon energy lower than {sup 192}Ir, it still requires extensive shielding to deliver treatment. An alternative radionuclide for brachytherapy is {sup 170}Tm (Z=69) because it has three physical properties adequate for clinical practice: (a) 128.6 day half-life, (b) high specific activity, and (c) mean photon energy of 66.39 keV. The main drawback of this radionuclide is the low photon yield (six photons per 100 electrons emitted). The purpose of this work is to study the dosimetric characteristics of this radionuclide for potential use in HDR-brachytherapy. Methods: The authors have assumed a theoretical {sup 170}Tm cylindrical source encapsulated with stainless steel and typical dimensions taken from the currently available HDR {sup 192}Ir brachytherapy sources. The dose-rate distribution was calculated for this source using the GEANT4 Monte Carlo (MC) code considering both photon and electron {sup 170}Tm spectra. The AAPM TG-43 U1 brachytherapy dosimetry parameters were derived. To study general properties of {sup 170}Tm encapsulated sources, spherical sources encapsulated with stainless steel and platinum were also studied. Moreover, the influence of small variations in the active core and capsule dimensions on the dosimetric characteristics was assessed. Treatment times required for a {sup 170}Tm source were compared to those for {sup 192}Ir and {sup 169}Yb for the same contained activity. Results: Due to the energetic beta spectrum and the large electron yield, the bremsstrahlung contribution to the dose was of the same order of magnitude as from the

  12. Dose optimisation in single plane interstitial brachytherapy

    DEFF Research Database (Denmark)

    Tanderup, Kari; Hellebust, Taran Paulsen; Honoré, Henriette Benedicte;

    2006-01-01

    BACKGROUND AND PURPOSE: Brachytherapy dose distributions can be optimised       by modulation of source dwell times. In this study dose optimisation in       single planar interstitial implants was evaluated in order to quantify the       potential benefit in patients. MATERIAL AND METHODS: In 14...

  13. CT-based interstitial HDR brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kolotas, C.; Baltas, D.; Zamboglou, N. [Staedtische Kliniken Offenbach (Germany). Strahlenklinik

    1999-09-01

    Purpose: Development, application and evaluation of a CT-guided implantation technique and a fully CT-based treatment planning procedure for brachytherapy. Methods and Materials: A brachytherapy procedure based on CT-guided implantation technique and CT-based treatment planning has been developed and clinical evaluated. For this purpose a software system (PROMETHEUS) for the 3D reconstruction of brachytherapy catheters and patient anatomy using only CT scans has been developed. An interface for the Nucletron PLATO BPS treatment planning system for optimization and calculation of dose distribution has been devised. The planning target volume(s) are defined as sets of points using contouring tools and are used for optimization of the 3D dose distribution. Dose-volume histogram based analysis of the dose distribution (COIN analysis) enables a clinically realistic evaluation of the brachytherapy application to be made. The CT-guided implantation of catheters and the CT-based treatment planning procedure has been performed for interstitial brachytherapy and for different tumor sites in 197 patients between 1996 and 1997. Results: The accuracy of the CT reconstruction was tested using first a quality assurance phantom and second, a simulated interstitial implant of 12 needles. These were compared with the results of reconstruction using radiographs. Both methods gave comparable results with regard to accuracy, but the CT based reconstruction was faster. Clinical feasibility was proved in pre-irradiated recurrences of brain tumors, in pretreated recurrences or metastatic disease, and in breast carcinomas. The tumor volumes treated were in the range 5.1 to 2,741 cm{sup 3}. Analysis of implant quality showed a slightly significant lower COIN value for the bone implants, but no differences with respect to the planning target volume. Conclusions: The Offenbach system, incorporating the PROMETHEUS software for interstitial HDR brachytherapy has proved to be extremely valuable

  14. Automated intraoperative calibration for prostate cancer brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kuiran Chen, Thomas; Heffter, Tamas; Lasso, Andras; Pinter, Csaba; Abolmaesumi, Purang; Burdette, E. Clif; Fichtinger, Gabor [Queen' s University, Kingston, Ontario K7L 3N6 (Canada); University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada); Acoustic MedSystems, Inc., Champaign, Illinois 61820-3979 (United States); Queen' s University, Kingston, Ontario K7L 3N6 (Canada) and Johns Hopkins University, Baltimore, Maryland 21218-2682 (United States)

    2011-11-15

    Purpose: Prostate cancer brachytherapy relies on an accurate spatial registration between the implant needles and the TRUS image, called ''calibration''. The authors propose a new device and a fast, automatic method to calibrate the brachytherapy system in the operating room, with instant error feedback. Methods: A device was CAD-designed and precision-engineered, which mechanically couples a calibration phantom with an exact replica of the standard brachytherapy template. From real-time TRUS images acquired from the calibration device and processed by the calibration system, the coordinate transformation between the brachytherapy template and the TRUS images was computed automatically. The system instantly generated a report of the target reconstruction accuracy based on the current calibration outcome. Results: Four types of validation tests were conducted. First, 50 independent, real-time calibration trials yielded an average of 0.57 {+-} 0.13 mm line reconstruction error (LRE) relative to ground truth. Second, the averaged LRE was 0.37 {+-} 0.25 mm relative to ground truth in tests with six different commercial TRUS scanners operating at similar imaging settings. Furthermore, testing with five different commercial stepper systems yielded an average of 0.29 {+-} 0.16 mm LRE relative to ground truth. Finally, the system achieved an average of 0.56 {+-} 0.27 mm target registration error (TRE) relative to ground truth in needle insertion tests through the template in a water tank. Conclusions: The proposed automatic, intraoperative calibration system for prostate cancer brachytherapy has achieved high accuracy, precision, and robustness.

  15. Prostate cancer brachytherapy; Braquiterapia de cancer de prostata

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Carlos Eduardo Vita; Silva, Joao L. F. [Hospital Sirio Libanes, Sao Paulo, SP (Brazil). Centro de Oncologia. Dep. de Radioterapia; Srougi, Miguel; Nesrallah, Adriano [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Escola Paulista de Medicina (EPM). Disciplina de Urologia]. E-mail: cevitabr@mandic.com.br

    1999-07-01

    The transperineal brachytherapy with {sup 125}I/Pd{sup 103} seed implantation guided by transurethral ultrasound must be presented as therapeutical option of low urinary morbidity in patients with localized prostate cancer. The combined clinical staging - including Gleason and initial PSA - must be encouraged, for definition of a group of low risk and indication of exclusive brachytherapy. Random prospective studies are necessary in order to define the best role of brachytherapy, surgery and external beam radiation therapy.

  16. Clinical implementation of MR‐guided vaginal cylinder brachytherapy

    National Research Council Canada - National Science Library

    Owrangi, Amir M; Jolly, Shruti; Balter, James M; Cao, Yue; Maturen, Katherine E; Young, Lisa; Zhu, Tong; Prisciandaro, Joann I

    2015-01-01

    ...)‐guided vaginal brachytherapy using commercially available solid applicator models. To test the fidelity of solid applicator models to digitize vaginal cylinder applicators, three datasets were evaluated...

  17. State-of-the-art: prostate LDR brachytherapy.

    Science.gov (United States)

    Voulgaris, S; Nobes, J P; Laing, R W; Langley, S E M

    2008-01-01

    This article on low dose rate (LDR) prostate brachytherapy reviews long-term results, patient selection and quality of life issues. Mature results from the United States and United Kingdom are reported and issues regarding definitions of biochemical failure are discussed. Latest data comparing brachytherapy with radical prostatectomy or no definitive treatment and also the risk of secondary malignancies after prostate brachytherapy are presented. Urological parameters of patient selection and quality of life issues concerning urinary, sexual and bowel function are reviewed. The position of prostate brachytherapy next to surgery as a first-line treatment modality is demonstrated.

  18. Dosimetric study of surface applicators of HDR brachytherapy GammaMed Plus equipment

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Rivera, E., E-mail: eric-1985@fisica.ugto.mx, E-mail: modesto@fisica.ugto.mx, E-mail: uvaldoreyes@fisica.ugto.mx; Sosa, M., E-mail: eric-1985@fisica.ugto.mx, E-mail: modesto@fisica.ugto.mx, E-mail: uvaldoreyes@fisica.ugto.mx; Reyes, U., E-mail: eric-1985@fisica.ugto.mx, E-mail: modesto@fisica.ugto.mx, E-mail: uvaldoreyes@fisica.ugto.mx; Jesús Bernal-Alvarado, José de, E-mail: bernal@fisica.ugto.mx, E-mail: theo@fisica.ugto.mx, E-mail: gil@fisica.ugto.mx; Córdova, T., E-mail: bernal@fisica.ugto.mx, E-mail: theo@fisica.ugto.mx, E-mail: gil@fisica.ugto.mx; Gil-Villegas, A., E-mail: bernal@fisica.ugto.mx, E-mail: theo@fisica.ugto.mx, E-mail: gil@fisica.ugto.mx [División de Ciencias e Ingenierías, Universidad de Guanajuato, 37150 León, Gto. (Mexico); Monzón, E., E-mail: emonzon@imss.gob.mx [Unidad de Alta Especialidad No.1, Instituto Mexicano del Seguro Social, Léon, Gto. (Mexico)

    2014-11-07

    The cone type surface applicators used in HDR brachytherapy for treatment of small skin lesions are an alternative to be used with both electron beams and orthovoltage X-ray equipment. For a good treatment planning is necessary to know the dose distribution of these applicators, which can be obtained by experimental measurement and Monte Carlo simulation as well. In this study the dose distribution of surface applicators of 3 and 3.5 cm diameter, respectively of HDR brachytherapy GammaMed Plus equipment has been estimated using the Monte Carlo method, MCNP code. The applicators simulated were placed on the surface of a water phantom of 20 × 20 × 20 cm and the dose was calculated at depths from 0 to 3 cm with increments of 0.25 mm. The dose profiles obtained at depth show the expected gradients for surface therapy.

  19. Design and optimization of a brachytherapy robot

    Science.gov (United States)

    Meltsner, Michael A.

    Trans-rectal ultrasound guided (TRUS) low dose rate (LDR) interstitial brachytherapy has become a popular procedure for the treatment of prostate cancer, the most common type of non-skin cancer among men. The current TRUS technique of LDR implantation may result in less than ideal coverage of the tumor with increased risk of negative response such as rectal toxicity and urinary retention. This technique is limited by the skill of the physician performing the implant, the accuracy of needle localization, and the inherent weaknesses of the procedure itself. The treatment may require 100 or more sources and 25 needles, compounding the inaccuracy of the needle localization procedure. A robot designed for prostate brachytherapy may increase the accuracy of needle placement while minimizing the effect of physician technique in the TRUS procedure. Furthermore, a robot may improve associated toxicities by utilizing angled insertions and freeing implantations from constraints applied by the 0.5 cm-spaced template used in the TRUS method. Within our group, Lin et al. have designed a new type of LDR source. The "directional" source is a seed designed to be partially shielded. Thus, a directional, or anisotropic, source does not emit radiation in all directions. The source can be oriented to irradiate cancerous tissues while sparing normal ones. This type of source necessitates a new, highly accurate method for localization in 6 degrees of freedom. A robot is the best way to accomplish this task accurately. The following presentation of work describes the invention and optimization of a new prostate brachytherapy robot that fulfills these goals. Furthermore, some research has been dedicated to the use of the robot to perform needle insertion tasks (brachytherapy, biopsy, RF ablation, etc.) in nearly any other soft tissue in the body. This can be accomplished with the robot combined with automatic, magnetic tracking.

  20. A fibre optic dosimeter customised for brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Suchowerska, N. [Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, NSW 2050 (Australia); School of Physics, University of Sydney, NSW 2006 (Australia)], E-mail: Natalka@email.cs.nsw.gov.au; Lambert, J.; Nakano, T. [Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, NSW 2050 (Australia); School of Physics, University of Sydney, NSW 2006 (Australia); Law, S. [School of Physics, University of Sydney, NSW 2006 (Australia); Optical Fibre Technology Centre, University of Sydney, 206 National Innovation Centre, Australian Technology Park, Eveleigh, NSW 1430 (Australia); Elsey, J. [Bandwidth Foundry Pty Ltd, Australian Technology Park, NSW, 1430 (Australia); McKenzie, D.R. [School of Physics, University of Sydney, NSW 2006 (Australia)

    2007-04-15

    In-vivo dosimetry for brachytherapy cancer treatment requires a small dosimeter with a real time readout capability that can be inserted into the patient to determine the dose to critical organs. Fibre optic scintillation dosimeters, consisting of a plastic scintillator coupled to an optical fibre, are a promising dosimeter for this application. We have implemented specific design features to optimise the performance of the dosimeter for specific in-vivo dosimetry during brachytherapy. Two sizes of the BrachyFOD{sup TM} scintillation dosimeter have been developed, with external diameters of approximately 2 and 1 mm. We have determined their important dosimetric characteristics (depth dose relation, angular dependence, energy dependence). We have shown that the background signal created by Cerenkov and fibre fluorescence does not significantly affect the performance in most clinical geometries. The dosimeter design enables readout at less than 0.5 s intervals. The clinical demands of real time in-vivo brachytherapy dosimetry can uniquely be satisfied by the BrachyFOD{sup TM}.

  1. Brachytherapy for the treatment of prostate cancer.

    Science.gov (United States)

    Cesaretti, Jamie A; Stone, Nelson N; Skouteris, Vassilios M; Park, Janelle L; Stock, Richard G

    2007-01-01

    Low-dose rate brachytherapy has become a mainstream treatment option for men diagnosed with prostate cancer because of excellent long-term treatment outcomes in low-, intermediate-, and high-risk patients. Largely due to patient lead advocacy for minimally invasive treatment options, high-quality prostate implants have become widely available in the US, Europe, and Japan. The reason that brachytherapy results are reproducible in several different practice settings is because numerous implant quality factors have been defined over the last 20 years, which can be applied objectively to judge the success of the intervention both during and after the procedure. In addition, recent long-term follow-up studies have clarified that the secondary cancer incidence of brachytherapy is not clinically meaningful. In terms of future directions, the study of radiation repair genetics may allow for the counseling physician to better estimate any given patients risk for side effects, thereby substantially reducing the therapeutic uncertainties faced by patients choosing a prostate cancer intervention.

  2. A robotic device for MRI-guided prostate brachytherapy

    NARCIS (Netherlands)

    Lagerburg, V.

    2008-01-01

    One of the treatment options for prostate cancer is brachytherapy with iodine-125 sources. In prostate brachytherapy a high radiation dose is delivered to the prostate with a steep dose fall off to critical surrounding organs. The implantation of the iodine sources is currently performed under

  3. A robotic device for MRI-guided prostate brachytherapy

    NARCIS (Netherlands)

    Lagerburg, V.

    2008-01-01

    One of the treatment options for prostate cancer is brachytherapy with iodine-125 sources. In prostate brachytherapy a high radiation dose is delivered to the prostate with a steep dose fall off to critical surrounding organs. The implantation of the iodine sources is currently performed under ultra

  4. Monte Carlo study of the impact of a magnetic field on the dose distribution in MRI-guided HDR brachytherapy using Ir-192

    NARCIS (Netherlands)

    Beld, E; Seevinck, P R; Lagendijk, J J W; Viergever, M A; Moerland, M A

    2016-01-01

    In the process of developing a robotic MRI-guided high-dose-rate (HDR) prostate brachytherapy treatment, the influence of the MRI scanner's magnetic field on the dose distribution needs to be investigated. A magnetic field causes a deflection of electrons in the plane perpendicular to the magnetic f

  5. [Perioperative interstitial brachytherapy for recurrent keloid scars].

    Science.gov (United States)

    Rio, E; Bardet, E; Peuvrel, P; Martinet, L; Perrot, P; Baraer, F; Loirat, Y; Sartre, J-Y; Malard, O; Ferron, C; Dreno, B

    2010-01-01

    Evaluation of the results of perioperative interstitial brachytherapy with low dose-rate (LDR) Ir-192 in the treatment of keloid scars. We performed a retrospective analysis of 73 histologically confirmed keloids (from 58 patients) resistant to medicosurgical treated by surgical excision plus early perioperative brachytherapy. All lesions were initially symptomatic. Local control was evaluated by clinical evaluation. Functional and cosmetic results were assessed in terms of patient responses to a self-administered questionnaire. Median age was 28 years (range 13-71 years). Scars were located as follows: 37% on the face, 32% on the trunk or abdomen, 16% on the neck, and 15% on the arms or legs. The mean delay before loading was four hours (range, 1-6h). The median dose was 20Gy (range, 15-40Gy). Sixty-four scars (from 53 patients) were evaluated. Local control was 86% (follow-up, 44.5 months; range, 14-150 months). All relapses occurred early - within 2 years posttreatment. At 20 months, survival without recurrence was significantly lower when treated lengths were more than 6cm long. The rate was 100% for treated scars below 4.5cm in length, 95% (95% CI: 55-96) for those 4.5-6cm long, and 75% (95% CI: 56-88) beyond 6cm (p=0.038). Of the 35 scars (28 patients) whose results were reassessed, six remained symptomatic and the esthetic results were considered to be good in 51% (18/35) and average in 37% (13/35) (median follow-up, 70 months; range, 16-181 months). Early perioperative LDR brachytherapy delivering 20Gy at 5mm reduced the rate of recurrent keloids resistant to other treatments and gave good functional results. 2009 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  6. The application of Geant4 simulation code for brachytherapy treatment

    CERN Document Server

    Agostinelli, S; Garelli, S; Paoli, G; Nieminen, P; Pia, M G

    2000-01-01

    Brachytherapy is a radiotherapeutic modality that makes use of radionuclides to deliver a high radiation dose to a well-defined volume while sparing surrounding healthy structures. At the National Institute for Cancer Research of Genova a High Dose Rate remote afterloading system provides Ir(192) endocavitary brachytherapy treatments. We studied the possibility to use the Geant4 Monte Carlo simulation toolkit in brachytherapy for calculation of complex physical parameters, not directly available by experiment al measurements, used in treatment planning dose deposition models.

  7. SU-E-T-564: Multi-Helix Rotating Shield Brachytherapy for Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Dadkhah, H; Wu, X [University of Iowa, Iowa City, IA (United States); Flynn, R; Kim, Y [University of Iowa Hospitals and Clinics, Iowa City, IA (United States)

    2015-06-15

    Purpose: To present a novel and practical brachytherapy technique, called multi-helix rotating shield brachytherapy (H-RSBT), for the precise positioning of a partial shield in a curved applicator. H-RSBT enables RSBT delivery using only translational motion of the radiation source/shield combination. H-RSBT overcomes the challenges associated with previously proposed RSBT approaches based on a serial (S-RSBT) step-and-shoot delivery technique, which required independent translational and rotational motion. Methods: A Fletcher-type applicator, compatible with the combination of a Xoft Axxent™ electronic brachytherapy source and a 0.5 mm thick tungsten shield, is proposed. The wall of the applicator contains six evenly-spaced helical keyways that rigidly define the emission direction of the shield as a function of depth. The shield contains three protruding keys and is attached to the source such that it rotates freely. S-RSBT and H-RSBT treatment plans with 180° and 45° azimuthal emission angles were generated for five cervical cancer patients representative of a wide range of high-risk clinical target volume (HR-CTV) shapes and applicator positions. The number of beamlets used in the treatment planning process was nearly constant for S-RSBT and H-RSBT by using dwell positions separated by 5 and 1.7 mm, respectively, and emission directions separated by 22.5° and 60°, respectively. For all the treatment plans the EQD2 of the HR-CTV was escalated until the EQD{sub 2cc} tolerance of either the bladder, rectum, or sigmoid colon was reached. Results: Treatment times for H-RSBT tended to be shorter than for S-RSBT, with changes of −38.47% to 1.12% with an average of −8.34%. The HR-CTV D{sub 90} changed by −8.81% to 2.08% with an average of −2.46%. Conclusion: H-RSBT is a mechanically feasible technique in the curved applicators needed for cervical cancer brachytherapy. S-RSBT and H-RSBT dose distributions were clinically equivalent for all patients

  8. Brachytherapy source characterization for improved dose calculations using primary and scatter dose separation.

    Science.gov (United States)

    Russell, Kellie R; Tedgren, Asa K Carlsson; Ahnesjö, Anders

    2005-09-01

    In brachytherapy, tissue heterogeneities, source shielding, and finite patient/phantom extensions affect both the primary and scatter dose distributions. The primary dose is, due to the short range of secondary electrons, dependent only on the distribution of material located on the ray line between the source and dose deposition site. The scatter dose depends on both the direct irradiation pattern and the distribution of material in a large volume surrounding the point of interest, i.e., a much larger volume must be included in calculations to integrate many small dose contributions. It is therefore of interest to consider different methods for the primary and the scatter dose calculation to improve calculation accuracy with limited computer resources. The algorithms in present clinical use ignore these effects causing systematic dose errors in brachytherapy treatment planning. In this work we review a primary and scatter dose separation formalism (PSS) for brachytherapy source characterization to support separate calculation of the primary and scatter dose contributions. We show how the resulting source characterization data can be used to drive more accurate dose calculations using collapsed cone superposition for scatter dose calculations. Two types of source characterization data paths are used: a direct Monte Carlo simulation in water phantoms with subsequent parameterization of the results, and an alternative data path built on processing of AAPM TG43 formatted data to provide similar parameter sets. The latter path is motivated of the large amounts of data already existing in the TG43 format. We demonstrate the PSS methods using both data paths for a clinical 192Ir source. Results are shown for two geometries: a finite but homogeneous water phantom, and a half-slab consisting of water and air. The dose distributions are compared to results from full Monte Carlo simulations and we show significant improvement in scatter dose calculations when the collapsed

  9. Image-guided high-dose-rate brachytherapy in inoperable endometrial cancer

    Science.gov (United States)

    Petsuksiri, J; Chansilpa, Y; Hoskin, P J

    2014-01-01

    Inoperable endometrial cancer may be treated with curative aim using radical radiotherapy alone. The radiation techniques are external beam radiotherapy (EBRT) alone, EBRT plus brachytherapy and brachytherapy alone. Recently, high-dose-rate brachytherapy has been used instead of low-dose-rate brachytherapy. Image-guided brachytherapy enables sufficient coverage of tumour and reduction of dose to the organs at risk, thus increasing the therapeutic ratio of treatment. Local control rates with three-dimensional brachytherapy appear better than with conventional techniques (about 90–100% and 70–90%, respectively). PMID:24807067

  10. Applying gold nanoparticles as tumor-vascular disrupting agents during brachytherapy: estimation of endothelial dose enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Ngwa, Wilfred; Makrigiorgos, G Mike; Berbeco, Ross I, E-mail: mmakrigiorgos@lroc.harvard.ed [Department of Radiation Oncology, Division of Medical Physics and Biophysics, Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02115 (United States)

    2010-11-07

    Tumor vascular disrupting agents (VDAs) represent a promising approach to the treatment of cancer, in view of the tumor vasculature's pivotal role in tumor survival, growth and metastasis. VDAs targeting the tumor's dysmorphic endothelial cells can cause selective and rapid occlusion of the tumor vasculature, leading to tumor cell death from ischemia and extensive hemorrhagic necrosis. In this study, the potential for applying gold nanoparticles (AuNPs) as VDAs, during brachytherapy, is examined. Analytic calculations based on the electron energy loss formula of Cole were carried out to estimate the endothelial dose enhancement caused by radiation-induced photo/Auger electrons originating from AuNPs targeting the tumor endothelium. The endothelial dose enhancement factor (EDEF), representing the ratio of the dose to the endothelium with and without gold nanoparticles was calculated for different AuNP local concentrations, and endothelial cell thicknesses. Four brachytherapy sources were investigated, I-125, Pd-103, Yb-169, as well as 50 kVp x-rays. The results reveal that, even at relatively low intra-vascular AuNP concentrations, ablative dose enhancement to tumor endothelial cells due to photo/Auger electrons from the AuNPs can be achieved. Pd-103 registered the highest EDEF values of 7.4-271.5 for local AuNP concentrations ranging from 7 to 350 mg g{sup -1}, respectively. Over the same concentration range, I-125, 50 kVp and Yb-169 yielded values of 6.4-219.9, 6.3-214.5 and 4.0-99.7, respectively. Calculations of the EDEF as a function of endothelial cell thickness showed that lower energy sources like Pd-103 reach the maximum EDEF at smaller thicknesses. The results also reveal that the highest contribution to the EDEF comes from Auger electrons, apparently due to their shorter range. Overall, the data suggest that ablative dose enhancement to tumor endothelial cells can be achieved by applying tumor vasculature-targeted AuNPs as adjuvants to

  11. A study of brachytherapy for intraocular tumor

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Yung Hoon; Lee, Dong Han; Ko, Kyung Hwan; Lee, Tae Won; Lee, Sung Koo; Choi, Moon Sik [Korea Cancer Center Hospital of Korea Atomic Energy Research Institute, Seoul (Korea, Republic of)

    1994-12-01

    Our purpose of this study is to perform brachytherapy for intraocular tumor. The result were as followed. 1. Eye model was determined as a 25 mm diameter sphere. Ir-192 was considered the most appropriate as radioisotope for brachytherapy, because of the size, half, energy and availability. 2. Considering the biological response with human tissue and protection of exposed dose, we made the plaques with gold, of which size were 15 mm, 17 mm and 20 mm in diameter, and 1.5 mm in thickness. 3. Transmission factor of plaques are all 0.71 with TLD and film dosimetry at the surface of plaques and 0.45, 0.49 at 1.5 mm distance of surface, respectively. 4. As compared the measured data for the plaque with Ir-192 seeds to results of computer dose calculation model by Gary Luxton et al. and CAP-PLAN (Radiation Treatment Planning System), absorbed doses are within {+-}10% and distance deviations are within 0.4 mm. Maximum error is -11.3% and 0.8 mm, respectively. 7 figs, 2 tabs, 28 refs. (Author).

  12. Improving photoacoustic imaging contrast of brachytherapy seeds

    Science.gov (United States)

    Pan, Leo; Baghani, Ali; Rohling, Robert; Abolmaesumi, Purang; Salcudean, Septimiu; Tang, Shuo

    2013-03-01

    Prostate brachytherapy is a form of radiotherapy for treating prostate cancer where the radiation sources are seeds inserted into the prostate. Accurate localization of seeds during prostate brachytherapy is essential to the success of intraoperative treatment planning. The current standard modality used in intraoperative seeds localization is transrectal ultrasound. Transrectal ultrasound, however, suffers in image quality due to several factors such speckle, shadowing, and off-axis seed orientation. Photoacoustic imaging, based on the photoacoustic phenomenon, is an emerging imaging modality. The contrast generating mechanism in photoacoustic imaging is optical absorption that is fundamentally different from conventional B-mode ultrasound which depicts changes in acoustic impedance. A photoacoustic imaging system is developed using a commercial ultrasound system. To improve imaging contrast and depth penetration, absorption enhancing coating is applied to the seeds. In comparison to bare seeds, approximately 18.5 dB increase in signal-to-noise ratio as well as a doubling of imaging depth are achieved. Our results demonstrate that the coating of the seeds can further improve the discernibility of the seeds.

  13. Image-Based Brachytherapy for the Treatment of Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Harkenrider, Matthew M., E-mail: mharkenrider@lumc.edu; Alite, Fiori; Silva, Scott R.; Small, William

    2015-07-15

    Cervical cancer is a disease that requires considerable multidisciplinary coordination of care and labor in order to maximize tumor control and survival while minimizing treatment-related toxicity. As with external beam radiation therapy, the use of advanced imaging and 3-dimensional treatment planning has generated a paradigm shift in the delivery of brachytherapy for the treatment of cervical cancer. The use of image-based brachytherapy, most commonly with magnetic resonance imaging (MRI), requires additional attention and effort by the treating physician to prescribe dose to the proper volume and account for adjacent organs at risk. This represents a dramatic change from the classic Manchester approach of orthogonal radiographic images and prescribing dose to point A. We reviewed the history and currently evolving data and recommendations for the clinical use of image-based brachytherapy with an emphasis on MRI-based brachytherapy.

  14. Patient release criteria for low dose rate brachytherapy implants.

    Science.gov (United States)

    Boyce, Dale E; Sheetz, Michael A

    2013-04-01

    A lack of consensus regarding a model governing the release of patients following sealed source brachytherapy has led to a set of patient release policies that vary from institution to institution. The U.S. Nuclear Regulatory Commission has issued regulatory guidance on patient release in NUREG 1556, Volume 9, Rev. 2, Appendix U, which allows calculation of release limits following implant brachytherapy. While the formalism presented in NUREG is meaningful for the calculation of release limits in the context of relatively high energy gamma emitters, it does not estimate accurately the effective dose equivalent for the common low dose rate brachytherapy sources Cs, I, and Pd. NUREG 1556 states that patient release may be based on patient-specific calculations as long as the calculation is documented. This work is intended to provide a format for patient-specific calculations to be used for the consideration of patients' release following the implantation of certain low dose rate brachytherapy isotopes.

  15. Brachytherapy on urethral carcinoma; Braquiterapia no carcinoma da uretra

    Energy Technology Data Exchange (ETDEWEB)

    Novaes, Paulo Eduardo R.S. [Fundacao Antonio Prudente, Sao Paulo, SP (Brazil). Hospital A.C. Camargo. Dept. de Radioterapia

    1996-04-01

    From 1954 to 1992 21 patients with primary urethral carcinoma were attended at A.C.Camargo Hospital - Fundacao Antonio Prudente - Sao Paulo. There were 17 female and 4 male with a median age of 58 years old. Eight patients received surgery, 8 radiation therapy and 5 were treated with palliative intention or were not treated. Patients treated by radiotherapy received 60 Gy to 80 Gy. Three patients were submitted to exclusive brachytherapy, 4 to the association of external beam and brachytherapy and 1 to external radiotherapy. Interstitial techniques were employed in 5 patients and intraluminal brachytherapy with special applicator in 2. Seven of 8 patients (87.5%) had local control and disease free survival with a minimum follow-up 4 years. Late effects were not observed. Primary urethral carcinoma is a curable disease by radiotherapy and the association of external irradiation and brachytherapy is the ideal approach. (author) 11 refs.

  16. Brachytherapy in thetreatment of the oral and oropharyngeal cancer

    Directory of Open Access Journals (Sweden)

    A. M. Zhumankulov

    2015-01-01

    Full Text Available Background. One of the methods of radiotherapy of malignant tumors of oral cavity and oropharyngeal region today is interstitial radiation therapy – brachytherapy, allowing you to create the optimum dose of irradiation to the tumor, necessary for its destruction, without severe radiation reactions in the surrounding tissues unchanged. Brachytherapy has the following advantages: high precision – the ability of the local summarization of high single doses in a limited volume of tissue; good tolerability; a short time of treatment. At this time, brachytherapy is the method of choice used as palliative therapy and as a component of radical treatment.Objective: The purpose of this article is a literature review about the latest achievements of interstitial brachytherapy in malignant tumors of the oral cavity and oropharynx.

  17. Radiotherapy and Brachytherapy : Proceedings of the NATO Advanced Study Institute on Physics of Modern Radiotherapy & Brachytherapy

    CERN Document Server

    Lemoigne, Yves

    2009-01-01

    This volume collects a series of lectures presented at the tenth ESI School held at Archamps (FR) in November 2007 and dedicated to radiotherapy and brachytherapy. The lectures focus on the multiple facets of radiotherapy in general, including external radiotherapy (often called teletherapy) as well as internal radiotherapy (called brachytherapy). Radiotherapy strategy and dose management as well as the decisive role of digital imaging in the associated clinical practice are developed in several articles. Grouped under the discipline of Conformal Radiotherapy (CRT), numerous modern techniques, from Multi-Leaf Collimators (MLC) to Intensity Modulated RadioTherapy (IMRT), are explained in detail. The importance of treatment planning based upon patient data from digital imaging (Computed Tomography) is also underlined. Finally, despite the quasi- totality of patients being presently treated with gamma and X-rays, novel powerful tools are emerging using proton and light ions (like carbon ions) beams, bound to bec...

  18. Electromagnetic tracking for treatment verification in interstitial brachytherapy

    Science.gov (United States)

    Kellermeier, Markus; Tanderup, Kari

    2016-01-01

    Electromagnetic tracking (EMT) is used in several medical fields to determine the position and orientation of dedicated sensors, e.g., attached to surgical tools. Recently, EMT has been introduced to brachytherapy for implant reconstruction and error detection. The manuscript briefly summarizes the main issues of EMT and error detection in brachytherapy. The potential and complementarity of EMT as treatment verification technology will be discussed in relation to in vivo dosimetry and imaging. PMID:27895688

  19. [Edge effect and late thrombosis -- inevitable complications of vascular brachytherapy?].

    Science.gov (United States)

    Schiele, T M; Staber, L; Kantlehner, R; Pöllinger, B; Dühmke, E; Theisen, K; Klauss, V

    2002-11-01

    Restenosis is the limiting entity after percutaneous coronary angioplasty. Vascular brachytherapy for the treatment of in-stent restenosis has been shown to reduce the repeat restenosis rate and the incidence of major adverse events in several randomized trials. Besides the beneficial effects, brachytherapy yielded some unwanted side effects. The development of new stenoses at the edges of the target lesion treated with radiation is termed edge effect. It occurs after afterloading brachytherapy as well as after implantation of radioactive stents. It is characterized by extensive intimal hyperplasia and negative remodeling. As contributing factors the axial dose fall-off, inherent to all radioactive sources, and the application of vessel wall trauma by angioplasty have been identified. The combination of both factors, by insufficient overlap of the radiation length over the injured vessel segment, has been referred to as geographic miss. It has been shown to be associated with a very high incidence of the edge effect. Avoidance of geographic miss is strongly recommended in vascular brachytherapy procedures. Late thrombosis after vascular brachytherapy is of multifactorial origin. It comprises platelet recruitment, fibrin deposition, disturbed vasomotion, non-healing dissection and stent malapposition predisposing to turbulent blood flow. The strongest predictors for late thrombosis are premature discontinuation of antiplatelet therapy and implantation of new stents during the brachytherapy procedure. With a consequent and prolonged antiplatelet therapy, the incidence of late thrombosis has been reduced to placebo levels. Edge effect and late thrombosis represent unwanted side effects of vascular brachytherapy. By means of a thorough treatment planning and prolonged antiplatelet therapy their incidences can be largely reduced. With regard to the very favorable net effect, they do not constitute relevant limitations of vascular brachytherapy.

  20. Review of advanced catheter technologies in radiation oncology brachytherapy procedures

    OpenAIRE

    Zhou J.; Zamdborg L; Sebastian E

    2015-01-01

    Jun Zhou,1,2 Leonid Zamdborg,1 Evelyn Sebastian1 1Department of Radiation Oncology, Beaumont Health System, 2Oakland University William Beaumont School of Medicine, Royal Oak, MI, USA Abstract: The development of new catheter and applicator technologies in recent years has significantly improved treatment accuracy, efficiency, and outcomes in brachytherapy. In this paper, we review these advances, focusing on the performance of catheter imaging and reconstruction techniques in brachytherapy ...

  1. Intraluminal brachytherapy in the treatment of bile duct carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Leung, J.T. [Adelaide Radiotherapy Centre, Adelaide, SA (Australia); Kuan, R. [Sir Charles Gairdner Hospital, Nedlands, Perth, WA (Australia)

    1997-05-01

    Patients with carcinoma of the biliary tract have a poor prognosis because the disease is often unresectable at diagnosis. Intraluminal brachytherapy has been reported as an effective treatment for localized cholangiocarcinoma of the biliary tract. The purpose of our study was to analyse the survival of patients treated with brachytherapy and make some recommendations regarding its use. Fifteen patients underwent brachytherapy via a trans-hepatic approach at the Royal Prince Alfred Hospital from 1983 to 1993. Eleven patients had low-dose rate brachytherapy and four patients had high-dose rate treatment. There were nine males and six females. The median age was 64 years. Other treatment included bypass procedures in two patients, endoscopic stents in 14 patients and external beam irradiation in one patient. The median survival was 12.5 months and 47% of the patients survived 1 year. The only complication reported was cholangitis which was seen in one patient. There did not seem to be any difference in survival or complications between low- and high-dose rate brachytherapy. It is concluded that the addition of intraluminal brachytherapy after biliary drainage prolongs survival and is a safe and effective treatment, but patients still have a high rate of local failure, and further studies will be needed to address this problem. (authors). 28 refs., 3 figs.

  2. 78 FR 41125 - Interim Enforcement Policy for Permanent Implant Brachytherapy Medical Event Reporting

    Science.gov (United States)

    2013-07-09

    ... COMMISSION Interim Enforcement Policy for Permanent Implant Brachytherapy Medical Event Reporting AGENCY... Commission (NRC) is issuing an interim Enforcement Policy that allows the staff to exercise enforcement...'s permanent implant brachytherapy program. This interim policy affects NRC licensees that...

  3. A review of the clinical experience in pulsed dose rate brachytherapy.

    Science.gov (United States)

    Balgobind, Brian V; Koedooder, Kees; Ordoñez Zúñiga, Diego; Dávila Fajardo, Raquel; Rasch, Coen R N; Pieters, Bradley R

    2015-01-01

    Pulsed dose rate (PDR) brachytherapy is a treatment modality that combines physical advantages of high dose rate (HDR) brachytherapy with the radiobiological advantages of low dose rate brachytherapy. The aim of this review was to describe the effective clinical use of PDR brachytherapy worldwide in different tumour locations. We found 66 articles reporting on clinical PDR brachytherapy including the treatment procedure and outcome. Moreover, PDR brachytherapy has been applied in almost all tumour sites for which brachytherapy is indicated and with good local control and low toxicity. The main advantage of PDR is, because of the small pulse sizes used, the ability to spare normal tissue. In certain cases, HDR resembles PDR brachytherapy by the use of multifractionated low-fraction dose.

  4. Interstitial brachytherapy in carcinoma of the penis

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhary, A.J.; Ghosh, S.; Bhalavat, R.L. [Tata Memorial Hospital, Mumbai (India). Dept. of Radiation Oncology; Kulkarni, J.N. [Tata Memorial Hospital, Mumbai (India). Dept. of Surgery; Sequeira, B.V.E. [Tata Memorial Hospital, Mumbai (India). Dept. of Medical Physics

    1999-01-01

    Aim: Keeping in line with the increasing emphasis on organ preservation, we at the Tata Memorial Hospital have evaluated the role of Ir-192 interstitial implant as regards local control, functional and cosmetic outcome in early as well as locally recurrent carcinoma of the distal penis. Patients and Methods: From October 1988 to December 1996, 23 patients with histopathologically proven cancer of the penis were treated with radical radiation therapy using Ir-192 temporary interstitial implant. Our patients were in the age group of 20 to 60 years. The primary lesions were T1 and 7, T2 in 7 and recurrent in 9 patients. Only 7 patients had palpable groin nodes at presentation, all of which were pathologically negative. The median dose of implant was 50 Gy (range 40 to 60 Gy), using the LDR afterloading system and the Paris system of implant rules for dosimetry. Follow-up ranged from 4 to 117 months (median 24 months). Results: At last follow-up 18 of the 23 patients remained locally controlled with implant alone. Three patients failed only locally, 2 locoregionally and 1 only at the groin. Of the 5 patients who failed locally, 4 were successfully salvaged with partial penectomy and remained controlled when last seen. Local control with implant alone at 8 years was 70% by life table analysis. The patients had excellent functional and cosmetic outcome. We did not record any case of skin or softtissue necrosis. Only 2 patients developed meatal stenosis, both of which were treated endoscopically. Conclusion: Our results lead us to interpret that interstitial brachytherapy with Ir-192 offers excellent local control rates with preservation of organ and function. Penectomy can be reserved as a means for effective salvage. (orig.) [Deutsch] Ziel: Das Prinzip des Organerhalts gewinnt in der Onkologie zunehmend an Bedeutung. Ziel dieser Untersuchung war es, die Rolle der interstitiellen Brachytherapie mit Ir-192 zur Behandlung des fruehen und rezidivierten Peniskarzinoms zu

  5. Methods for prostate stabilization during transperineal LDR brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Podder, Tarun; Yu Yan [Department of Radiation Oncology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Sherman, Jason [Department of Medical Physics, University of Buffalo, Buffalo, NY 14260 (United States); Rubens, Deborah; Strang, John [Departments of Imaging Science and Surgery, University of Rochester, Rochester, NY 14642 (United States); Messing, Edward [Departments of Urology and Surgery, University of Rochester, Rochester, NY 14642 (United States); Ng, Wan-Sing [School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2008-03-21

    In traditional prostate brachytherapy procedures for a low-dose-rate (LDR) radiation seed implant, stabilizing needles are first inserted to provide some rigidity and support to the prostate. Ideally this will provide better seed placement and an overall improved treatment. However, there is much speculation regarding the effectiveness of using regular brachytherapy needles as stabilizers. In this study, we explored the efficacy of two types of needle geometries (regular brachytherapy needle and hooked needle) and several clinically feasible configurations of the stabilization needles. To understand and assess the prostate movement during seed implantation, we collected in vivo data from patients during actual brachytherapy procedures. In vitro experimentation with tissue-equivalent phantoms allowed us to further understand the mechanics behind prostate stabilization. We observed superior stabilization with the hooked needles compared to the regular brachytherapy needles (more than 40% in bilateral parallel needle configuration). Prostate movement was also reduced significantly when regular brachytherapy needles were in an angulated configuration as compared to the parallel configuration (more than 60%). When the hooked needles were angulated for stabilization, further reduction in prostate displacement was observed. In general, for convenience of dosimetric planning and to avoid needle collision, all needles are desired to be in a parallel configuration. In this configuration, hooked needles provide improved stabilization of the prostate. On the other hand, both regular and hooked needles appear to be equally effective in reducing prostate movement when they are in angulated configurations, which will be useful in seed implantation using a robotic system. We have developed nonlinear spring-damper model for the prostate movement which can be used for adapting dosimetric planning during brachytherapy as well as for developing more realistic haptic devices and

  6. The role of brachytherapy in radiation and isotopes centre of Khartoum (RICK)

    CERN Document Server

    Ali, A M

    2000-01-01

    As there are many efforts devoted in order to manage the cancer, here the researcher handle one of these efforts that play a major part in treating the cancer internationally, it is a brachytherapy system. Brachytherapy was carried out mostly with radium sources, but recently some artificial sources are incorporated in this mode of treatment such as Cs-137, Ir-192, Au-198, P-32, Sr-90 and I-125. The research cover history of brachytherapy and radioactive sources used in, techniques of implementation, radiation protection and methods of brachytherapy dose calculation, as well as brachytherapy in radiation and isotopes centre in Khartoum.

  7. Utilization and Outcomes of Breast Brachytherapy in Younger Women

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Grace L. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Huo, Jinhai [Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Giordano, Sharon H. [Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hunt, Kelly K. [Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Buchholz, Thomas A. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Smith, Benjamin D., E-mail: bsmith3@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2015-09-01

    Purpose: To directly compare (1) radiation treatment utilization patterns; (2) risks of subsequent mastectomy; and (3) costs of radiation treatment in patients treated with brachytherapy versus whole-breast irradiation (WBI), in a national, contemporary cohort of women with incident breast cancer, aged 64 years and younger. Methods and Materials: Using MarketScan health care claims data, we identified 45,884 invasive breast cancer patients (aged 18-64 years), treated from 2003 to 2010 with lumpectomy, followed by brachytherapy (n=3134) or whole-breast irradiation (n=42,750). We stratified patients into risk groups according to age (Age<50 vs Age≥50) and endocrine therapy status (Endocrine− vs Endocrine+). “Endocrine+” patients filled an endocrine therapy prescription within 1 year after lumpectomy. Pathologic hormone receptor status was not available in this dataset. In brachytherapy versus WBI patients, utilization trends and 5-year subsequent mastectomy risks were compared. Stratified, adjusted subsequent mastectomy risks were calculated using proportional hazards regression. Results: Brachytherapy utilization increased from 2003 to 2010: in patients Age<50, from 0.6% to 4.9%; patients Age≥50 from 2.2% to 11.3%; Endocrine− patients, 1.3% to 9.4%; Endocrine+ patients, 1.9% to 9.7%. Age influenced treatment selection more than endocrine status: 17% of brachytherapy patients were Age<50 versus 32% of WBI patients (P<.001); whereas 41% of brachytherapy patients were Endocrine–versus 44% of WBI patients (P=.003). Highest absolute 5-year subsequent mastectomy risks occurred in Endocrine−/Age<50 patients (24.4% after brachytherapy vs 9.0% after WBI (hazard ratio [HR] 2.18, 95% confidence interval [CI] 1.37-3.47); intermediate risks in Endocrine−/Age≥50 patients (8.6% vs 4.9%; HR 1.76, 95% CI 1.26-2.46); and lowest risks in Endocrine+ patients of any age: Endocrine+/Age<50 (5.5% vs 4.5%; HR 1.18, 95% CI 0.61-2.31); Endocrine+/Age≥50 (4.2% vs 2

  8. Film based verification of calculation algorithms used for brachytherapy planning-getting ready for upcoming challenges of MBDCA.

    Science.gov (United States)

    Zwierzchowski, Grzegorz; Bielęda, Grzegorz; Skowronek, Janusz; Mazur, Magdalena

    2016-08-01

    Well-known defect of TG-43 based algorithms used in brachytherapy is a lack of information about interaction cross-sections, which are determined not only by electron density but also by atomic number. TG-186 recommendations with using of MBDCA (model-based dose calculation algorithm), accurate tissues segmentation, and the structure's elemental composition continue to create difficulties in brachytherapy dosimetry. For the clinical use of new algorithms, it is necessary to introduce reliable and repeatable methods of treatment planning systems (TPS) verification. The aim of this study is the verification of calculation algorithm used in TPS for shielded vaginal applicators as well as developing verification procedures for current and further use, based on the film dosimetry method. Calibration data was collected by separately irradiating 14 sheets of Gafchromic(®) EBT films with the doses from 0.25 Gy to 8.0 Gy using HDR (192)Ir source. Standard vaginal cylinders of three diameters were used in the water phantom. Measurements were performed without any shields and with three shields combination. Gamma analyses were performed using the VeriSoft(®) package. Calibration curve was determined as third-degree polynomial type. For all used diameters of unshielded cylinder and for all shields combinations, Gamma analysis were performed and showed that over 90% of analyzed points meets Gamma criteria (3%, 3 mm). Gamma analysis showed good agreement between dose distributions calculated using TPS and measured by Gafchromic films, thus showing the viability of using film dosimetry in brachytherapy.

  9. Biomaterial characteristics and application of silicone rubber and PVA hydrogels mimicked in organ groups for prostate brachytherapy.

    Science.gov (United States)

    Li, Pan; Jiang, Shan; Yu, Yan; Yang, Jun; Yang, Zhiyong

    2015-09-01

    It is definite that transparent material with similar structural characteristics and mechanical properties to human tissue is favorable for experimental study of prostate brachytherapy. In this paper, a kind of transparent polyvinyl alcohol (PVA) hydrogel and silicone rubber are developed as suitable substitutions for human soft tissue. Segmentation and 3D reconstruction of medical image are performed to manufacture the mould of organ groups through rapid prototyping technology. Micro-structure observation, force test and CCD deformation test have been conducted to investigate the structure and mechanical properties of PVA hydrogel used in organ group mockup. Scanning electron microscope (SEM) image comparison results show that PVA hydrogel consisting of 3 g PVA, 17 g de-ionized water, 80 g dimethyl-sulfoxide (DMSO), 4 g NaCl, 1.5 g NaOH, 3 g epichlorohydrin (ECH) and 7 freeze/thaw cycles reveals similar micro-structure to human prostate tissue. Through the insertion force comparison between organ group mockup and clinical prostate brachytherapy, PVA hydrogel and silicone rubber are found to have the same mechanical properties as prostate tissue and muscle. CCD deformation test results show that insertion force suffers a sharp decrease and a relaxation of tissue deformation appears when needle punctures the capsule of prostate model. The results exhibit that organ group mockup consisting of PVA hydrogel, silicone rubber, membrane and agarose satisfies the needs of prostate brachytherapy simulation in general and can be used to mimic the soft tissues in pelvic structure.

  10. Vaginal brachytherapy for postoperative endometrial cancer: 2014 Survey of the American Brachytherapy Society.

    Science.gov (United States)

    Harkenrider, Matthew M; Grover, Surbhi; Erickson, Beth A; Viswanathan, Akila N; Small, Christina; Kliethermes, Stephanie; Small, William

    2016-01-01

    Report current practice patterns for postoperative endometrial cancer emphasizing vaginal brachytherapy (VBT). A 38-item survey was e-mailed to 1,598 American Brachytherapy Society (ABS) members and 4,329 US radiation oncologists in 2014 totaling 5,710 recipients. Responses of practitioners who had delivered VBT in the previous 12 months were included in the analysis. Responses were tabulated to determine relative frequency distributions. χ(2) analysis was used to compare current results with those from the 2003 ABS survey. A total of 331 respondents initiated the VBT survey, of whom 289 (87.3%) administered VBT in the prior 12 months. Lymph node dissection and number of nodes removed influenced treatment decisions for 90.5% and 69.8%, respectively. High-dose-rate was used by 96.2%. The most common vaginal length treated was 4 cm (31.0%). Three-dimensional planning was used by 83.2% with 73.4% of those for the first fraction only. Doses to normal tissues were reported by 79.8%. About half optimized to the location of dose specification and/or normal tissues. As monotherapy, the most common prescriptions were 7 Gy for three fractions to 0.5-cm depth and 6 Gy for five fractions to the surface. As a boost, the most common prescriptions were 5 Gy for three fractions to 0.5-cm depth and 6 Gy for three fractions to the vaginal surface. Optimization points were placed at the apex and lateral vagina by 73.1%. Secondary quality assurance checks were performed by 98.9%. VBT is a common adjuvant therapy for endometrial cancer patients, most commonly with HDR. Fractionation and planning processes are variable but generally align with ABS recommendations. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  11. Irradiation and dosimetry of Nitinol stent for renal artery brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Arbabi, Azim [Science and Research Campus, Islamic Azad University, P.O. Box 14515-775, Tehran (Iran, Islamic Republic of); Shahid Beheshti Medical University, P.O. Box 14335-1419, Tehran (Iran, Islamic Republic of); Sadeghi, Mahdi [Science and Research Campus, Islamic Azad University, P.O. Box 14515-775, Tehran (Iran, Islamic Republic of); Nuclear Medicine Research Group, Agricultural, Medical and Industrial Research School, P.O. Box 31485-498, Karaj (Iran, Islamic Republic of)], E-mail: msadeghi@nrcam.org; Joharifard, Mahdi [Science and Research Campus, Islamic Azad University, P.O. Box 14515-775, Tehran (Iran, Islamic Republic of)

    2009-01-15

    This study was conducted to assess the suitability of {sup 48}V radioactive stent for use in renal artery brachytherapy. A nickel-titanium alloy Nitinol stent was irradiated over the proton energy range of up to 8.5 MeV, to obtain {sup 48}V. The depth dose distribution analysis of the activated stent was done with TLD-700GR in a Perspex phantom. We investigated a unique mixed gamma/beta brachytherapy source of {sup 48}V. For a 10 mm outer-diameter {sup 48}V stent, the average measured dose rate to vessel was 37 mGy/h. The dosimetry results of the {sup 48}V stent suggest that the stent is suitable for use in renal artery brachytherapy.

  12. Fast dose optimization for rotating shield brachytherapy.

    Science.gov (United States)

    Cho, Myung; Wu, Xiaodong; Dadkhah, Hossein; Yi, Jirong; Flynn, Ryan T; Kim, Yusung; Xu, Weiyu

    2017-07-26

    To provide a fast computational method, based on the proximal graph solver (POGS) - a convex optimization solver using the alternating direction method of multipliers (ADMM), for calculating an optimal treatment plan in rotating shield brachytherapy (RSBT). RSBT treatment planning has more degrees of freedom than conventional high-dose-rate brachytherapy due to the addition of emission direction, and this necessitates a fast optimization technique to enable clinical usage. The multi-helix RSBT (H-RSBT) delivery technique(1) was investigated for five representative cervical cancer patients. Treatment plans were generated for all patients using the POGS method and the commercially available solver IBM ILOG CPLEX(2) . The rectum, bladder, sigmoid colon, high-risk clinical target volume (HRCTV), and HR-CTV boundary were the structures included in our optimization, which applied an asymmetric dose-volume optimization with smoothness control. Dose calculation resolution was 1X1X3 mm(3) for all cases. The H-RSBT applicator had 6 helices, with 33:3 mm of translation along the applicator per helical rotation and 1:7 mm spacing between dwell positions, yielding 17.5° emission angle spacing per 5 mm along the applicator. For each patient, HR-CTV D90, HR-CTV D100, rectum D2cc, sigmoid D2cc, and bladder D2cc matched within 1% for CPLEX and POGS methods. Also, similar EQD2 values between CPLEX and POGS methods were obtained. POGS was around 18 times faster than CPLEX. Over all patients, total optimization times were 32.1-65.4 seconds for CPLEX and 2.1-3.9 seconds for POGS. POGS reduced treatment plan optimization time approximately 18 times for RSBT with similar HR-CTV D90, organ at risk (OAR) D2cc values, and EQD2 values compared to CPLEX, which is significant progress toward clinical translation of RSBT. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Interstitial rotating shield brachytherapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Quentin E., E-mail: quentin-adams@uiowa.edu; Xu, Jinghzu; Breitbach, Elizabeth K.; Li, Xing; Rockey, William R.; Kim, Yusung; Wu, Xiaodong; Flynn, Ryan T. [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Enger, Shirin A. [Medical Physics Unit, McGill University, 1650 Cedar Ave, Montreal, Quebec H3G 1A4 (Canada)

    2014-05-15

    Purpose: To present a novel needle, catheter, and radiation source system for interstitial rotating shield brachytherapy (I-RSBT) of the prostate. I-RSBT is a promising technique for reducing urethra, rectum, and bladder dose relative to conventional interstitial high-dose-rate brachytherapy (HDR-BT). Methods: A wire-mounted 62 GBq{sup 153}Gd source is proposed with an encapsulated diameter of 0.59 mm, active diameter of 0.44 mm, and active length of 10 mm. A concept model I-RSBT needle/catheter pair was constructed using concentric 50 and 75 μm thick nickel-titanium alloy (nitinol) tubes. The needle is 16-gauge (1.651 mm) in outer diameter and the catheter contains a 535 μm thick platinum shield. I-RSBT and conventional HDR-BT treatment plans for a prostate cancer patient were generated based on Monte Carlo dose calculations. In order to minimize urethral dose, urethral dose gradient volumes within 0–5 mm of the urethra surface were allowed to receive doses less than the prescribed dose of 100%. Results: The platinum shield reduced the dose rate on the shielded side of the source at 1 cm off-axis to 6.4% of the dose rate on the unshielded side. For the case considered, for the same minimum dose to the hottest 98% of the clinical target volume (D{sub 98%}), I-RSBT reduced urethral D{sub 0.1cc} below that of conventional HDR-BT by 29%, 33%, 38%, and 44% for urethral dose gradient volumes within 0, 1, 3, and 5 mm of the urethra surface, respectively. Percentages are expressed relative to the prescription dose of 100%. For the case considered, for the same urethral dose gradient volumes, rectum D{sub 1cc} was reduced by 7%, 6%, 6%, and 6%, respectively, and bladder D{sub 1cc} was reduced by 4%, 5%, 5%, and 6%, respectively. Treatment time to deliver 20 Gy with I-RSBT was 154 min with ten 62 GBq {sup 153}Gd sources. Conclusions: For the case considered, the proposed{sup 153}Gd-based I-RSBT system has the potential to lower the urethral dose relative to HDR-BT by 29

  14. A Scintillating Fiber Dosimeter for Radiology and Brachytherapy with photodiode readout

    CERN Document Server

    Rêgo, Florbela; Abreu, Maria da Conceição

    2011-01-01

    Purpose: For more than a decade that plastic optical fiber based dosimeters have been developed for medical applications. The feasibility of dosimeters using optical fibers that are almost Cherenkov light free has been demonstrated in some prototypes, particularly suitable for photon high-energy beams. In the energy range up to a few hundred keV, where the production of Cherenkov light by secondary electrons is negligible or small, the largest source of background are the fluorescence mechanisms. Methods: In recent years our group has developed an optical fiber dosimeter with photodiode readout named DosFib, which has small energy dependence in the range below 100 keV relevant for radiology. Photodiodes are robust photodetectors, presenting good stability over time and enough sensitivity to allow the use of an electrometer as a measuring device without extra electronics. Results: In-vitro tests using a High Dose Rate 192Ir source have demonstrated its suitability for brachytherapy applications using this impo...

  15. Radioactive seed migration following parotid gland interstitial brachytherapy.

    Science.gov (United States)

    Fan, Yi; Huang, Ming-Wei; Zhao, Yi-Jiao; Gao, Hong; Zhang, Jian-Guo

    2017-09-15

    To evaluate the incidence and associated factors of pulmonary seed migration after parotid brachytherapy using a novel migrated seed detection technique. Patients diagnosed with parotid cancer who underwent permanent parotid brachytherapy from January 2006 to December 2011 were reviewed retrospectively. Head and neck CT scans and chest X-rays were evaluated during routine follow-up. Mimics software and Geomagic Studio software were used for seed reconstruction and migrated seed detection from the original implanted region, respectively. Postimplant dosimetry analysis was performed after seeds migration if the seeds were still in their emitting count. Adverse clinical sequelae from seed embolization to the lung were documented. The radioactive seed implants were identified on chest X-rays in 6 patients. The incidence rate of seed migration in 321 parotid brachytherapy patients was 1.87% (6/321) and that of individual seed migration was 0.04% (6/15218 seeds). All migrated seeds were originally from the retromandibular region. No adverse dosimetric consequences were found in the target region. Pulmonary symptoms were not reported by any patient in this study. In our patient set, migration of radioactive seeds with an initial radioactivity of 0.6-0.7 mCi to the chest following parotid brachytherapy was rare. Late migration of a single seed from the central target region did not affect the dosimetry significantly, and patients did not have severe short-term complications. This study proposed a novel technique to localize the anatomical origin of the migrated seeds during brachytherapy. Our evidence suggested that placement of seeds adjacent to blood vessels was associated with an increased likelihood of seed migration to the lungs. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  16. Developing a Verification and Training Phantom for Gynecological Brachytherapy System

    Directory of Open Access Journals (Sweden)

    Mahbobeh Nazarnejad

    2012-03-01

    Full Text Available Introduction Dosimetric accuracy is a major issue in the quality assurance (QA program for treatment planning systems (TPS. An important contribution to this process has been a proper dosimetry method to guarantee the accuracy of delivered dose to the tumor. In brachytherapy (BT of gynecological (Gyn cancer it is usual to insert a combination of tandem and ovoid applicators with a complicated geometry which makes their dosimetry verification difficult and important. Therefore, evaluation and verification of dose distribution is necessary for accurate dose delivery to the patients. Materials and Methods The solid phantom was made from Perspex slabs as a tool for intracavitary brachytherapy dosimetric QA. Film dosimetry (EDR2 was done for a combination of ovoid and tandem applicators introduced by Flexitron brachytherapy system. Treatment planning was also done with Flexiplan 3D-TPS to irradiate films sandwiched between phantom slabs. Isodose curves obtained from treatment planning system and the films were compared with each other in 2D and 3D manners. Results The brachytherapy solid phantom was constructed with slabs. It was possible to insert tandems and ovoids loaded with radioactive source of Ir-192 subsequently. Relative error was 3-8.6% and average relative error was 5.08% in comparison with the films and TPS isodose curves. Conclusion Our results showed that the difference between TPS and the measurements is well within the acceptable boundaries and below the action level according to AAPM TG.45. Our findings showed that this phantom after minor corrections can be used as a method of choice for inter-comparison analysis of TPS and to fill the existing gap for accurate QA program in intracavitary brachytherapy. The constructed phantom also showed that it can be a valuable tool for verification of accurate dose delivery to the patients as well as training for brachytherapy residents and physics students.

  17. TU-F-201-03: Applications in Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Trichter, S. [New York Weill Cornell Medical Ctr (United States)

    2015-06-15

    Since the introduction of radiochromic films (RCF) for radiation dosimetry, the scope of RCF dosimetry has expanded steadily to include many medical applications, such as radiation therapy and diagnostic radiology. The AAPM Task Group (TG) 55 published a report on the recommendations for RCF dosimetry in 1998. As the technology is advancing rapidly, and its routine clinical use is expanding, TG 235 has been formed to provide an update to TG-55 on radiochromic film dosimetry. RCF dosimetry applications in clinical radiotherapy have become even more widespread, expanding from primarily brachytherapy and radiosurgery applications, and gravitating towards (but not limited to) external beam therapy (photon, electron and protons), such as quality assurance for IMRT, VMAT, Tomotherapy, SRS/SRT, and SBRT. In addition, RCF applications now extend to measurements of radiation dose in particle beams and patients undergoing medical exams, especially fluoroscopically guided interventional procedures and CT. The densitometers/scanners used for RCF dosimetry have also evolved from the He-Ne laser scanner to CCD-based scanners, including roller-based scanner, light box-based digital camera, and flatbed color scanner. More recently, multichannel RCF dosimetry introduced a new paradigm for external beam dose QA for its high accuracy and efficiency. This course covers in detail the recent advancements in RCF dosimetry. Learning Objectives: Introduce the paradigm shift on multichannel film dosimetry Outline the procedures to achieve accurate dosimetry with a RCF dosimetry system Provide comprehensive guidelines on RCF dosimetry for various clinical applications One of the speakers has a research agreement from Ashland Inc., the manufacturer of Gafchromic film.

  18. Dosimetry in intravascular brachytherapy; Calculos dosimetricos em braquiterapia intravascular

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Laelia Pumilla Botelho

    2000-03-01

    Among the cardiovascular diseases responsible for deaths in the adult population in almost all countries of the world, the most common is acute myocardial infarction, which generally occurs because of the occlusion of one or more coronary arteries. Several diagnostic techniques and therapies are being tested for the treatment of coronary artery disease. Balloon angioplasty has been a popular treatment which is less invasive than traditional surgeries involving revascularization of the myocardium, thus promising a better quality of life for patients. Unfortunately, the rate of restenosis (re-closing of the vessel) after balloon angioplasty is high (approximately 30-50% within the first year after treatment).Recently, the idea of delivering high radiation doses to coronary arteries to avoid or delay restenosis has been suggested. Known as intravascular brachytherapy, the technique has been used with several radiation sources, and researchers have obtained success in decreasing the rate of restenosis in some patient populations. In order to study the radiation dosimetry in the patient and radiological protection for the attending staff for this therapy, radiation dose distributions for monoenergetic electrons and photons (at nine discrete energies) were calculated for blood vessels of diameter 0.15, o,30 and 0.45 cm with balloon and wire sources using the radiation transport code MCNP4B. Specific calculations were carried out for several candidate radionuclides as well. Two s tent sources (metallic prosthesis that put inside of patient's artery through angioplasty) employing {sup 32} P are also simulated. Advantages and disadvantages of the various radionuclides and source geometries are discussed. The dosimetry developed here will aid in the realization of the benefits obtained in patients for this promising new technology. (author)

  19. Validation of GPUMCD for low-energy brachytherapy seed dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Hissoiny, Sami; Ozell, Benoit; Despres, Philippe; Carrier, Jean-Francois [Ecole polytechnique de Montreal, Departement de genie informatique et genie logiciel, 2500 chemin de Polytechnique, Montreal, QC, H3T 1J4 (Canada); Departement de radio-oncologie, Centre hospitalier universitaire de Quebec (CHUQ), 11 Cote du Palais, Quebec, QC, G1R 2J6 (Canada); Departement de physique, Universite de Montreal, Montreal, QC (Canada) and Departement de radio-oncologie and Centre de recherche du CHUM, Centre hospitalier de l' Universite de Montreal (CHUM), Montreal, QC, H2L 4M1 (Canada)

    2011-07-15

    Purpose: To validate GPUMCD, a new package for fast Monte Carlo dose calculations based on the GPU (graphics processing unit), as a tool for low-energy single seed brachytherapy dosimetry for specific seed models. As the currently accepted method of dose calculation in low-energy brachytherapy computations relies on severe approximations, a Monte Carlo based approach would result in more accurate dose calculations, taking in to consideration the patient anatomy as well as interseed attenuation. The first step is to evaluate the capability of GPUMCD to reproduce low-energy, single source, brachytherapy calculations which could ultimately result in fast and accurate, Monte Carlo based, brachytherapy dose calculations for routine planning. Methods: A mixed geometry engine was integrated to GPUMCD capable of handling parametric as well as voxelized geometries. In order to evaluate GPUMCD for brachytherapy calculations, several dosimetry parameters were computed and compared to values found in the literature. These parameters, defined by the AAPM Task-Group No. 43, are the radial dose function, the 2D anisotropy function, and the dose rate constant. These three parameters were computed for two different brachytherapy sources: the Amersham OncoSeed 6711 and the Imagyn IsoStar IS-12501. Results: GPUMCD was shown to yield dosimetric parameters similar to those found in the literature. It reproduces radial dose functions to within 1.25% for both sources in the 0.5< r <10 cm range. The 2D anisotropy function was found to be within 3% at r = 5 cm and within 4% at r = 1 cm. The dose rate constants obtained were within the range of other values reported in the literature.Conclusion: GPUMCD was shown to be able to reproduce various TG-43 parameters for two different low-energy brachytherapy sources found in the literature. The next step is to test GPUMCD as a fast clinical Monte Carlo brachytherapy dose calculations with multiple seeds and patient geometry, potentially providing

  20. Imaging method for monitoring delivery of high dose rate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Weisenberger, Andrew G; Majewski, Stanislaw

    2012-10-23

    A method for in-situ monitoring both the balloon/cavity and the radioactive source in brachytherapy treatment utilizing using at least one pair of miniature gamma cameras to acquire separate images of: 1) the radioactive source as it is moved in the tumor volume during brachytherapy; and 2) a relatively low intensity radiation source produced by either an injected radiopharmaceutical rendering cancerous tissue visible or from a radioactive solution filling a balloon surgically implanted into the cavity formed by the surgical resection of a tumor.

  1. Current state of the art brachytherapy treatment planning dosimetry algorithms.

    Science.gov (United States)

    Papagiannis, P; Pantelis, E; Karaiskos, P

    2014-09-01

    Following literature contributions delineating the deficiencies introduced by the approximations of conventional brachytherapy dosimetry, different model-based dosimetry algorithms have been incorporated into commercial systems for (192)Ir brachytherapy treatment planning. The calculation settings of these algorithms are pre-configured according to criteria established by their developers for optimizing computation speed vs accuracy. Their clinical use is hence straightforward. A basic understanding of these algorithms and their limitations is essential, however, for commissioning; detecting differences from conventional algorithms; explaining their origin; assessing their impact; and maintaining global uniformity of clinical practice.

  2. Uncertainty analysis in MCNP5 calculations for brachytherapy treatment

    Energy Technology Data Exchange (ETDEWEB)

    Gerardy, I., E-mail: gerardy@isib.be [Institut Superieur Industriel de Bruxelles, 150, Rue Royale, B-1000 Brussels (Belgium); Rodenas, J.; Gallardo, S. [Departamento de Ingenieria Quimica y Nuclear, Universidad Politecnica de Valencia (Spain)

    2011-08-15

    The Monte Carlo (MC) method can be applied to simulate brachytherapy treatment planning. The MCNP5 code gives, together with results, a statistical uncertainty associated with them. However, the latter is not the only existing uncertainty related to the simulation and other uncertainties must be taken into account. A complete analysis of all sources of uncertainty having some influence on results of the simulation of brachytherapy treatment is presented in this paper. This analysis has been based on the recommendations of the American Association for Physicist in Medicine (AAPM) and of the International Standard Organisation (ISO).

  3. Epimacular brachytherapy for wet AMD: current perspectives.

    Science.gov (United States)

    Casaroli-Marano, Ricardo P; Alforja, Socorro; Giralt, Joan; Farah, Michel E

    2014-01-01

    Age-related macular degeneration (AMD) is considered the most common cause of blindness in the over-60 age group in developed countries. There are basically two forms of presentation: geographic (dry or atrophic) and wet (neovascular or exudative). Geographic atrophy accounts for approximately 85%-90% of ophthalmic frames and leads to a progressive degeneration of the retinal pigment epithelium and the photoreceptors. Wet AMD causes the highest percentage of central vision loss secondary to disease. This neovascular form involves an angiogenic process in which newly formed choroidal vessels invade the macular area. Today, intravitreal anti-angiogenic drugs attempt to block the angiogenic events and represent a major advance in the treatment of wet AMD. Currently, combination therapy for wet AMD includes different forms of radiation delivery. Epimacular brachytherapy (EMBT) seems to be a useful approach to be associated with current anti-vascular endothelial growth factor agents, presenting an acceptable efficacy and safety profile. However, at the present stage of research, the results of the clinical trials carried out to date are insufficient to justify extending routine use of EMBT for the treatment of wet AMD.

  4. An approach to using conventional brachytherapy software for clinical treatment planning of complex, Monte Carlo-based brachytherapy dose distributions

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, Mark J.; Melhus, Christopher S.; Granero, Domingo; Perez-Calatayud, Jose; Ballester, Facundo [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Radiation Oncology Department, Physics Section, ' ' La Fe' ' University Hospital, Avenida Campanar 21, E-46009 Valencia (Spain); Department of Atomic, Molecular, and Nuclear Physics, University of Valencia, C/Dr. Moliner 50, E-46100 Burjassot, Spain and IFIC (University of Valencia-CSIC), C/Dr. Moliner 50, E-46100 Burjassot (Spain)

    2009-06-15

    Certain brachytherapy dose distributions, such as those for LDR prostate implants, are readily modeled by treatment planning systems (TPS) that use the superposition principle of individual seed dose distributions to calculate the total dose distribution. However, dose distributions for brachytherapy treatments using high-Z shields or having significant material heterogeneities are not currently well modeled using conventional TPS. The purpose of this study is to establish a new treatment planning technique (Tufts technique) that could be applied in some clinical situations where the conventional approach is not acceptable and dose distributions present cylindrical symmetry. Dose distributions from complex brachytherapy source configurations determined with Monte Carlo methods were used as input data. These source distributions included the 2 and 3 cm diameter Valencia skin applicators from Nucletron, 4-8 cm diameter AccuBoost peripheral breast brachytherapy applicators from Advanced Radiation Therapy, and a 16 mm COMS-based eye plaque using {sup 103}Pd, {sup 125}I, and {sup 131}Cs seeds. Radial dose functions and 2D anisotropy functions were obtained by positioning the coordinate system origin along the dose distribution cylindrical axis of symmetry. Origin:tissue distance and active length were chosen to minimize TPS interpolation errors. Dosimetry parameters were entered into the PINNACLE TPS, and dose distributions were subsequently calculated and compared to the original Monte Carlo-derived dose distributions. The new planning technique was able to reproduce brachytherapy dose distributions for all three applicator types, producing dosimetric agreement typically within 2% when compared with Monte Carlo-derived dose distributions. Agreement between Monte Carlo-derived and planned dose distributions improved as the spatial resolution of the fitted dosimetry parameters improved. For agreement within 5% throughout the clinical volume, spatial resolution of

  5. In vivo dosimetry: trends and prospects for brachytherapy

    DEFF Research Database (Denmark)

    Kertzscher, Gustavo; Rosenfeld, A.; Beddar, S.

    2014-01-01

    The error types during brachytherapy (BT) treatments and their occurrence rates are not well known. The limited knowledge is partly attributed to the lack of independent verification systems of the treatment progression in the clinical workflow routine. Within the field of in vivo dosimetry (IVD)...

  6. Electromagnetic tracking for treatment verification in interstitial brachytherapy

    DEFF Research Database (Denmark)

    Bert, Christoph; Kellermeier, Markus; Tanderup, Kari

    2016-01-01

    Electromagnetic tracking (EMT) is used in several medical fields to determine the position and orientation of dedicated sensors, e.g., attached to surgical tools. Recently, EMT has been introduced to brachytherapy for implant reconstruction and error detection. The manuscript briefly summarizes...

  7. Pulsed dose rate brachytherapy – is it the right way?

    Directory of Open Access Journals (Sweden)

    Janusz Skowronek

    2010-10-01

    Full Text Available Pulsed dose rate (PDR-BT treatment is a brachytherapy modality that combines physical advantages of high-doserate (HDR-BT technology (isodose optimization, radiation safety with the radiobiological advantages of low-dose-rate (LDR-BT brachytherapy. Pulsed brachytherapy consists of using stronger radiation source than for LDR-BT and producing series of short exposures of 10 to 30 minutes in every hour to approximately the same total dose in the sameoverall time as with the LDR-BT. Modern afterloading equipment offers certain advantages over interstitial or intracavitaryinsertion of separate needles, tubes, seeds or wires. Isodose volumes in tissues can be created flexibly by a combinationof careful placement of the catheter and the adjustment of the dwell times of the computerized stepping source.Automatic removal of the radiation sources into a shielded safe eliminates radiation exposures to staff and visitors.Radiation exposure is also eliminated to the staff who formerly loaded and unloaded multiplicity of radioactive sources into the catheters, ovoids, tubes etc. This review based on summarized clinical investigations, analyses the feasibility and the background to introduce this brachytherapy technique and chosen clinical applications of PDR-BT.

  8. Electromagnetic tracking for treatment verification in interstitial brachytherapy

    DEFF Research Database (Denmark)

    Bert, Christoph; Kellermeier, Markus; Tanderup, Kari

    2016-01-01

    Electromagnetic tracking (EMT) is used in several medical fields to determine the position and orientation of dedicated sensors, e.g., attached to surgical tools. Recently, EMT has been introduced to brachytherapy for implant reconstruction and error detection. The manuscript briefly summarizes...

  9. Brachytherapy optimal planning with application to intravascular radiation therapy

    DEFF Research Database (Denmark)

    Sadegh, Payman; Mourtada, Firas A.; Taylor, Russell H.;

    1999-01-01

    . Dose rate calculations are based on the sosimetry formulation of the American Association of Physicists in Medicine, Task Group 43. We apply the technique to optimal planning for intravascular brachytherapy of intimal hyperplasia using ultrasound data and 192Ir seeds. The planning includes...

  10. Remote Afterloading High Dose Rate Brachytherapy AMC EXPERIANCES

    Energy Technology Data Exchange (ETDEWEB)

    Park, Su Gyong; Chang, Hye Sook; Choi, Eun Kyong; Yi, Byong Yong [Ulsan University College of Medicine, Seoul (Korea, Republic of)

    1992-12-15

    Remote afterloading high dose rate brachytherapy(HDRB) is a new technology and needs new biological principle for time and dose schedule. Here, authors attempt to evaluate the technique and clinical outcome in 116 patients, 590 procedures performed at Asan Medical Center for 3 years. From Sep. 1985 to Aug 1992, 471 procedures of intracavitary radiation in 55 patients of cervical cancer and 26 of nasopharyngeal cancer, 79 intraluminal radiation in 12 of esophageal cancer, 11 of endobronchial cancer and 1 Klatskin tumor and 40 interstitial brachytherapy in 4 of breast cancer, 1 sarcoma and 1 urethral cancer were performed. Median follow-up was 7 months with range 1-31 months. All procedures except interstitial were performed under the local anesthesia and they were all well tolerated and completed the planned therapy except 6 patients. 53/58 patients with cervical cancer and 22/26 patients with nasopharynx cancer achieved CR. Among 15 patients with palliative therapy, 80% achieves palliation. We will describe the details of the technique and results in the text. To evaluate biologic effects of HDRB and optimal time/dose/fractionation schedule, we need longer follow-up. But authors feel that HDRB with proper fractionation schedule may yield superior results compared to the low dose rate brachytherapy considering the advantages of HDRB in safety factor for operator, better control of radiation dose and volume and patients comfort over the low dose brachytherapy.

  11. Factors influencing outcome of I-125 prostate cancer brachytherapy

    NARCIS (Netherlands)

    Hinnen, K.A.

    2011-01-01

    Brachytherapy is becoming an increasingly popular prostate cancer treatment, probably due to the specific advantages of the procedure, such as the minimal invasiveness and the lower chance of impotence and incontinence. Nonetheless, because of the long follow-up that is required to obtain prostate

  12. Photoacoustic imaging of prostate brachytherapy seeds in ex vivo prostate

    Science.gov (United States)

    Kuo, Nathanael; Kang, Hyun Jae; DeJournett, Travis; Spicer, James; Boctor, Emad

    2011-03-01

    The localization of brachytherapy seeds in relation to the prostate is a key step in intraoperative treatment planning (ITP) for improving outcomes in prostate cancer patients treated with low dose rate prostate brachytherapy. Transrectal ultrasound (TRUS) has traditionally been the modality of choice to guide the prostate brachytherapy procedure due to its relatively low cost and apparent ease of use. However, TRUS is unable to visualize seeds well, precluding ITP and producing suboptimal results. While other modalities such as X-ray and magnetic resonance imaging have been investigated to localize seeds in relation to the prostate, photoacoustic imaging has become an emerging and promising modality to solve this challenge. Moreover, photoacoustic imaging may be more practical in the clinical setting compared to other methods since it adds little additional equipment to the ultrasound system already adopted in procedure today, reducing cost and simplifying engineering steps. In this paper, we demonstrate the latest efforts of localizing prostate brachytherapy seeds using photoacoustic imaging, including visualization of multiple seeds in actual prostate tissue. Although there are still several challenges to be met before photoacoustic imaging can be used in the operating room, we are pleased to present the current progress in this effort.

  13. Verification of Oncentra brachytherapy planning using independent calculation

    Science.gov (United States)

    Safian, N. A. M.; Abdullah, N. H.; Abdullah, R.; Chiang, C. S.

    2016-03-01

    This study was done to investigate the verification technique of treatment plan quality assurance for brachytherapy. It is aimed to verify the point doses in 192Ir high dose rate (HDR) brachytherapy between Oncentra Masterplan brachytherapy treatment planning system and independent calculation software at a region of rectum, bladder and prescription points for both pair ovoids and full catheter set ups. The Oncentra TPS output text files were automatically loaded into the verification programme that has been developed based on spreadsheets. The output consists of source coordinates, desired calculation point coordinates and the dwell time of a patient plan. The source strength and reference dates were entered into the programme and then dose point calculations were independently performed. The programme shows its results in a comparison of its calculated point doses with the corresponding Oncentra TPS outcome. From the total of 40 clinical cases that consisted of two fractions for 20 patients, the results that were given in term of percentage difference, it shows an agreement between TPS and independent calculation are in the range of 2%. This programme only takes a few minutes to be used is preferably recommended to be implemented as the verification technique in clinical brachytherapy dosimetry.

  14. Initial application of digital tomosynthesis to improve brachytherapy treatment planning

    Science.gov (United States)

    Baydush, Alan H.; Mirzaei McKee, Mahta; King, June; Godfrey, Devon J.

    2007-03-01

    We present preliminary investigations that examine the feasibility of incorporating volumetric images generated using digital tomosynthesis into brachytherapy treatment planning. The Integrated Brachytherapy Unit (IBU) at our facility consists of an L-arm, C-arm isocentric motion system with an x-ray tube and fluoroscopic imager attached. Clinically, this unit is used to generate oblique, anterior-posterior, and lateral images for simple treatment planning and dose prescriptions. Oncologists would strongly prefer to have volumetric data to better determine three dimensional dose distributions (dose-volume histograms) to the target area and organs at risk. Moving the patient back and forth to CT causes undo stress on the patient, allows extensive motion of organs and treatment applicators, and adds additional time to patient treatment. We propose to use the IBU imaging system with digital tomosynthesis to generate volumetric patient data, which can be used for improving treatment planning and overall reducing treatment time. Initial image data sets will be acquired over a limited arc of a human-like phantom composed of real bones and tissue equivalent material. A brachytherapy applicator will be incorporated into one of the phantoms for visualization purposes. Digital tomosynthesis will be used to generate a volumetric image of this phantom setup. This volumetric image set will be visually inspected to determine the feasibility of future incorporation of these types of images into brachytherapy treatment planning. We conclude that initial images using the tomosynthesis reconstruction technique show much promise and bode well for future work.

  15. Stepping source prostate brachytherapy: From target definition to dose delivery

    NARCIS (Netherlands)

    Dinkla, A.M.

    2015-01-01

    Brachytherapy is an effective way to treat tumours locally and conformally, and is widely used in the treatment of prostate cancer. Prior to the treatment, a CT or MRI scan is acquired. The use of MRI led to a mean increase of 3% in dose coverage of the target volume (chapter 2). Although this seems

  16. Brachytherapy treatment planning algorithm applied to prostate cancer

    Science.gov (United States)

    Herrera-Rodríguez, M. R.; Martínez-Dávalos, A.

    2000-10-01

    An application of Genetic Algorithms (GAs) for treatment planning optimization in prostate brachytherapy is presented. The importance of multi-objective selection criteria based on the contour of the volume of interest and radiosensitive structures such as the rectum and urethra is discussed. First results are obtained for a simple test case which presents radial symmetry.

  17. Radiological response of lanthanum guiding seeds in brachytherapy implants; Resposta radiologica de sementes guia de lantanio em implantes braquiterapicos

    Energy Technology Data Exchange (ETDEWEB)

    Silva, L.S.R.; Machado, E.D.P., E-mail: lais26@globo.com [Centro Federal de Educacao Tecnologica de Minas Gerais, Belo Horizonte, MG (Brazil). Departamento de Engenharia de Materiais; Campos, T.P.R. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Roberto, W.S. [Centro Federal de Educacao Tecnologica de Minas Gerais, Belo Horizonte, MG (Brazil). Departamento de Fisica e Matematica

    2013-08-15

    Ceramic seeds with La-139 incorporated were synthesized to be used as radiological guides in brachytherapy implants. The synthesis was performed based on the sol-gel method. The seeds were subjected to characterization by Scanning Electron Microscopy, X-ray diffraction and Energy-Dispersive X-ray Spectroscopy. Furthermore, the contrast from a radiographic film was evaluated to lanthanum, samarium and holmium seeds. Radiological response on a phantom at different depths with lanthanum seeds and metal seeds was also investigated. Based on the values of contrast, the synthesized lanthanum seeds can be considered efficient as radiological guides when implanted together with pure Ho-165 and Sm-152 seeds. (author)

  18. Comparative dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Samia de Freitas, E-mail: samiabrandao@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Campos, Tarcisio Passos Ribeiro de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2013-06-15

    Objective: comparative analysis of dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for treatment of brain tumors. Materials and methods: simulations of intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT were performed with the MCNP5 code, modeling the treatment of a brain tumor on a voxel computational phantom representing a human head. Absorbed dose rates were converted into biologically weighted dose rates. Results: intracavitary balloon catheter brachytherapy with I-125 produced biologically weighted mean dose rates of 3.2E-11, 1.3E-10, 1.9E-11 and 6.9E-13 RBE.Gy.h{sup -1}.p{sup -1}.s, respectively, on the healthy tissue, on the balloon periphery and on the /{sub 1} and /{sub 2} tumor infiltration zones. On the other hand, Cf-252 brachytherapy combined with BNCT produced a biologically weighted mean dose rate of 5.2E-09, 2.3E-07, 8.7E-09 and 2.4E-09 RBE.Gy.h{sup -1}.p{sup -1}.s, respectively on the healthy tissue, on the target tumor and on the /{sub 1} and /{sub 2} infiltration zones. Conclusion: Cf-252 brachytherapy combined with BNCT delivered a selective irradiation to the target tumor and to infiltration zones, while intracavitary balloon catheter brachytherapy with I-125 delivered negligible doses on the tumor infiltration zones. (author)

  19. Patient effective dose from endovascular brachytherapy with 192Ir sources.

    Science.gov (United States)

    Perma, L; Bianchi, C; Nicolini, G; Novario, R; Tanzi, F; Conte, L

    2002-01-01

    The growing use of endovascular brachytherapy has been accompanied by the publication of a large number of studies in several fields, but few studies on patient dose have been found in the literature. Moreover, these studies were carried out on the basis of Monte Carlo simulation. The aim of the present study was to estimate the effective dose to the patient undergoing endovascular brachytherapy treatment with 112Ir sources, by means of experimental measurements. Two standard treatments were taken into account: an endovascular brachytherapy of the coronary artery corresponding to the activity x time product of 184 GBq.min and an endovascular brachytherapy of the renal artery (898 GBq.min). Experimental assessment was accomplished by thermoluminescence dosemeters positioned in more than 300 measurement points in a properly adapted Rqndo phantom. A method has been developed to estimate the mean organ doses for all tissues and organs concerned in order to calculate the effective dose associated with intravascular brachytherapy. The normalised organ doses resulting from cronary treatment were 2.4 x 10(-2) mSv.GBq(-1).min(-1) for lung, 0.9 x 10(-2) mSv.GBSq(-1).min(-1) for oesophagus and 0.48 x 10(-2) mS.GBq(-1).min(-1) for bone marrow. During brachytherapy of the renal artery, the corresponding normalised doses were 4.2 x 10(-2) mS.GBq(-1).min(-1) for colon, 7.8 x 10(-2) mSv.GBq(-1).min(-1) for stomach and 1.7 x 10(-2) mSv.GBq(-1).min(-1) for liver. Coronary treatment iJnvlled an efl'fective dose of (0.046 mSv.GBq(-1).min(-1), whereas the treatment of the renal artery resulted in an effective dose of 0.15 mSv.GBq(-1).min(-1); there were many similarities with data from former studies. Based on these results it can be concluded that the dose level of patients exposed during brachytherapy treatment is low.

  20. Epimacular brachytherapy for wet AMD: current perspectives

    Directory of Open Access Journals (Sweden)

    Casaroli-Marano RP

    2014-08-01

    Full Text Available Ricardo P Casaroli-Marano,1,2 Socorro Alforja,1 Joan Giralt,1 Michel E Farah2 1Instituto Clínic de Oftalmología (Hospital Clínic de Barcelona, University of Barcelona, Barcelona, Spain; 2Department of Ophthalmology and Visual Sciences, Universidade Federal de Sao Paulo, Escola Paulista de Medicina, Sao Paulo, Brazil Abstract: Age-related macular degeneration (AMD is considered the most common cause of blindness in the over-60 age group in developed countries. There are basically two forms of presentation: geographic (dry or atrophic and wet (neovascular or exudative. Geographic atrophy accounts for approximately 85%–90% of ophthalmic frames and leads to a progressive degeneration of the retinal pigment epithelium and the photoreceptors. Wet AMD causes the highest percentage of central vision loss secondary to disease. This neovascular form involves an angiogenic process in which newly formed choroidal vessels invade the macular area. Today, intravitreal anti-angiogenic drugs attempt to block the angiogenic events and represent a major advance in the treatment of wet AMD. Currently, combination therapy for wet AMD includes different forms of radiation delivery. Epimacular brachytherapy (EMBT seems to be a useful approach to be associated with current anti-vascular endothelial growth factor agents, presenting an acceptable efficacy and safety profile. However, at the present stage of research, the results of the clinical trials carried out to date are insufficient to justify extending routine use of EMBT for the treatment of wet AMD. Keywords: macular degeneration, radiation, vascular endothelial growth factor, combined therapy, intravitreal therapy, vitrectomy

  1. Brachytherapy dose measurements in heterogeneous tissues

    Energy Technology Data Exchange (ETDEWEB)

    Paiva F, G.; Luvizotto, J.; Salles C, T.; Guimaraes A, P. C.; Dalledone S, P. de T.; Yoriyaz, H. [Instituto de Pesquisas Energeticas e Nucleares / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil); Rubo, R., E-mail: gabrielpaivafonseca@gmail.com [Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, 05403-900 Sao Paulo (Brazil)

    2014-08-15

    Recently, Beau lieu et al. published an article providing guidance for Model-Based Dose Calculation Algorithms (MBDCAs), where tissue heterogeneity considerations are addressed. It is well-known that T G-43 formalism which considers only water medium is limited and significant dose differences have been found comparing both methodologies. The aim of the present work is to experimentally quantify dose values in heterogeneous medium using different dose measurement methods and techniques and compare them with those obtained with Monte Carlo simulations. Experiments have been performed using a Nucletron micro Selectron-Hdr Ir-192 brachytherapy source and a heterogeneous phantom composed by PMMA and different tissue equivalent cylinders like bone, lungs and muscle. Several dose measurements were obtained using tissue equivalent materials with height 1.8 cm and 4.3 cm positioned between the radiation source and the detectors. Radiochromic films, TLDs and MOSFET S have been used for the dose measurements. Film dosimetry has been performed using two methodologies: a) linearization for dose-response curve based on calibration curves to create a functional form that linearize s the dose response and b) 177 multichannel analysis dosimetry where the multiple color channels are analyzed allowing to address not only disturbances in the measurements caused by thickness variation in the film layer, but also, separate other external influences in the film response. All experiments have been simulated using the MCNP5 Monte Carlo radiation transport code. Comparison of experimental results are in good agreement with calculated dose values with differences less than 6% for almost all cases. (Author)

  2. Radiation pneumonitis caused by a migrated brachytherapy seed lodged in the lung.

    Science.gov (United States)

    Miura, Noriyoshi; Kusuhara, Yoshito; Numata, Kousaku; Shirato, Akitomi; Hashine, Katsuyoshi; Sumiyoshi, Yoshiteru; Kataoka, Masaaki; Takechi, Shinsuke

    2008-09-01

    We report a case of radiation pneumonitis caused by a migrated seed lodged in the lung after prostate brachytherapy. A 71-year-old man underwent transperineal interstitial permanent prostate brachytherapy for localized prostate cancer. On the day after brachytherapy, a routine postimplant chest X-ray revealed migration of one seed to the lower lobe of the left lung. After 1 month, pulmonary opacities were observed in the left lower lobe but not near the seed. He was diagnosed with bacterial pneumonia, and antibiotic therapy was commenced. Two months after brachytherapy, the patient's symptoms, laboratory data and pulmonary opacities improved; however, an abnormal shadow (consolidation) developed around the migrated seed. Lung consolidation disappeared almost completely 12 months after brachytherapy without any medical treatment. The abnormal shadow probably represented radiation pneumonitis. To the best of our knowledge, this is the first report of radiation pneumonitis caused by a migrated brachytherapy seed in the lung.

  3. Three-dimensional ultrasound system for guided breast brachytherapy.

    Science.gov (United States)

    De Jean, Paul; Beaulieu, Luc; Fenster, Aaron

    2009-11-01

    Breast-conserving surgery combined with subsequent radiation therapy is a standard procedure in breast cancer treatment. The disadvantage of whole-breast beam irradiation is that it requires 20-25 treatment days, which is inconvenient for patients with limited mobility or who reside far from the treatment center. However, interstitial high-dose-rate (HDR) brachytherapy is an irradiation method requiring only 5 treatment days and that delivers a lower radiation dose to the surrounding healthy tissue. It involves delivering radiation through 192Ir seeds placed inside the catheters, which are inserted into the breast. The catheters are attached to a HDR afterloader, which controls the seed placement within the catheters and irradiation times to deliver the proper radiation dose. One disadvantage of using HDR brachytherapy is that it requires performing at least one CT scan during treatment planning. The procedure at our institution involves the use of two CT scans. Performing CT scans requires moving the patient from the brachytherapy suite with catheters inserted in their breasts. One alternative is using three-dimensional ultrasound (3DUS) to image the patient. In this study, the authors developed a 3DUS translation scanning system for use in breast brachytherapy. The new system was validated using CT, the current clinical standard, to image catheters in a breast phantom. Once the CT and 3DUS images were registered, the catheter trajectories were then compared. The results showed that the average angular separation between catheter trajectories was 2.4 degrees, the average maximum trajectory separation was 1.0 mm, and the average mean trajectory separation was found to be 0.7 mm. In this article, the authors present the 3DUS translation scanning system's capabilities as well as its potential to be used as the primary treatment planning imaging modality in breast brachytherapy.

  4. Gold nanoparticle-aided brachytherapy with vascular dose painting: estimation of dose enhancement to the tumor endothelial cell nucleus.

    Science.gov (United States)

    Ngwa, Wilfred; Makrigiorgos, G Mike; Berbeco, Ross I

    2012-01-01

    Theoretical microdosimetry at the subcellular level is employed in this study to estimate the dose enhancement to tumor endothelial cell nuclei, caused by radiation-induced photo/Auger electrons originating from gold nanoparticles (AuNPs) targeting the tumor endothelium, during brachytherapy. A tumor vascular endothelial cell (EC) is modeled as a slab of 2 μm (thickness) × 10 μm (length) × 10 μm (width). The EC contains a nucleus of 5 μm diameter and thickness of 0.5-1 μm, corresponding to nucleus size 5%-10% of cellular volume, respectively. Analytic calculations based on the electron energy loss formula of Cole were carried out to estimate the dose enhancement to the nucleus caused by photo/Auger electrons from AuNPs attached to the exterior surface of the EC. The nucleus dose enhancement factor (nDEF), representing the ratio of the dose to the nucleus with and without the presence of gold nanoparticles was calculated for different AuNP local concentrations. The investigated concentration range considers the potential for significantly higher local concentration near the EC due to preferential accumulation of AuNP in the tumor vasculature. Four brachytherapy sources: I-125, Pd-103, Yb-169, and 50 kVp x-rays were investigated. For nucleus size of 10% of the cellular volume and AuNP concentrations ranging from 7 to 140 mg/g, brachytherapy sources Pd-103, I-125, 50 kVp, and Yb-169 yielded nDEF values of 5.6-73, 4.8-58.3, 4.7-56.6, and 3.2-25.8, respectively. Meanwhile, for nucleus size 5% of the cellular volume in the same concentration range, Pd-103, I-125, 50 kVp, and Yb-169 yielded nDEF values of 6.9-79.2, 5.1-63.2, 5.0-61.5, and 3.3-28.3, respectively. The results predict that a substantial dose boost to the nucleus of endothelial cells can be achieved by applying tumor vasculature-targeted AuNPs in combination with brachytherapy. Such vascular dose boosts could induce tumor vascular shutdown, prompting extensive tumor cell death.

  5. Experimental dosimetry of a {sup 32}P catheter-based endovascular brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Piermattei, A [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Fidanzio, A [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Perrone, F [Azienda Ospedaliera Pisana, UO Fisica Sanitaria, Pisa (Italy); Azario, L [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Grimaldi, L [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Viola, P [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Capote, R [Dpto Fisiologia Medica y Biofisica, Facultad de Medicina, Universidad de Sevilla, Avda Sanchez Pizjuan 4, E41009 Sevilla (Spain)

    2003-08-07

    The experimental dosimetry in a water phantom of a {sup 32}P linear source, 20 mm in length, used for the brachytherapy of coronary vessels is reported. The source content activity, A, was determined by means of a calibrated well ion-chamber and the value was compared with the contained activity reported in the manufacturer's certification. In this field of brachytherapy dosimetry, radiochromic film supplies a high enough spatial resolution. A highly sensitive radiochromic film, that presents only one active layer, was used in this work for the source dosimetry in a water phantom. The radiochromic film was characterized by electron beams produced by a clinical linac. A Monte Carlo calculation of beta spectra in water at different distances along the source transverse bisector axis allowed to take into account the low dependence of film response from the electron beam energy. The adopted experimental set-up, with the source in its catheter positioned on the film plane inside the water phantom, supplies accurate dosimetric information. The measured dose rate to water per unit of source activity at reference distance, D-dot (r{sub 0}, {theta}{sub 0})/A, in units of cGy s{sup -1} GBq{sup -1}, was in agreement with the value reported in the manufacturer's certification within the experimental uncertainty. The radial dose function, g(r), is in good agreement with the literature data. The anisotropy function F(r, {theta}) is also reported. The analysis of the dose profile obtained at 2 mm from the source longitudinal axis shows that the uniformity is within 10% along 75% of the 20 mm treatment length. The adopted experimental set-up seems to be adequate for the quality control procedure of the dose homogeneity distribution in the water medium.

  6. Image guided, adaptive, accelerated, high dose brachytherapy as model for advanced small volume radiotherapy.

    Science.gov (United States)

    Haie-Meder, Christine; Siebert, Frank-André; Pötter, Richard

    2011-09-01

    Brachytherapy has consistently provided a very conformal radiation therapy modality. Over the last two decades this has been associated with significant improvements in imaging for brachytherapy applications (prostate, gynecology), resulting in many positive advances in treatment planning, application techniques and clinical outcome. This is emphasized by the increased use of brachytherapy in Europe with gynecology as continuous basis and prostate and breast as more recently growing fields. Image guidance enables exact knowledge of the applicator together with improved visualization of tumor and target volumes as well as of organs at risk providing the basis for very individualized 3D and 4D treatment planning. In this commentary the most important recent developments in prostate, gynecological and breast brachytherapy are reviewed, with a focus on European recent and current research aiming at the definition of areas for important future research. Moreover the positive impact of GEC-ESTRO recommendations and the highlights of brachytherapy physics are discussed what altogether presents a full overview of modern image guided brachytherapy. An overview is finally provided on past and current international brachytherapy publications focusing on "Radiotherapy and Oncology". These data show tremendous increase in almost all research areas over the last three decades strongly influenced recently by translational research in regard to imaging and technology. In order to provide high level clinical evidence for future brachytherapy practice the strong need for comprehensive prospective clinical research addressing brachytherapy issues is high-lighted. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. dose in cervical cancer intracavitary brachytherapy

    Directory of Open Access Journals (Sweden)

    Zahra Siavashpour

    2016-04-01

    Full Text Available Purpose: To analyze the optimum organ filling point for organs at risk (OARs dose in cervical cancer high-dose-rate (HDR brachytherapy. Material and methods : In a retrospective study, 32 locally advanced cervical cancer patients (97 insertions who were treated with 3D conformal external beam radiation therapy (EBRT and concurrent chemotherapy during 2010-2013 were included. Rotterdam HDR tandem-ovoid applicators were used and computed tomography (CT scanning was performed after each insertion. The OARs delineation and GEC-ESTRO-based clinical target volumes (CTVs contouring was followed by 3D forward planning. Then, dose volume histogram (DVH parameters of organs were recorded and patients were classified based on their OARs volumes, as well as their inserted tandem length. Results : The absorbed dose to point A ranged between 6.5-7.5 Gy. D 0.1cm ³ and D 2cm ³ of the bladder significantly increased with the bladder volume enlargement (p value < 0.05. By increasing the bladder volume up to about 140 cm3, the rectum dose was also increased. For the cases with bladder volumes higher than 140 cm3, the rectum dose decreased. For bladder volumes lower than 75 cm3, the sigmoid dose decreased; however, for bladder volumes higher than 75 cm3, the sigmoid dose increased. The D 2cm ³ of the bladder and rectum were higher for longer tandems than for shorter ones, respectively. The divergence of the obtained results for different tandem lengths became wider by the extension of the bladder volume. The rectum and sigmoid volume had a direct impact on increasing their D 0.1cm ³ and D 2cm ³, as well as decreasing their D 10 , D 30 , and D 50 . Conclusions : There is a relationship between the volumes of OARs and their received doses. Selecting a bladder with a volume of about 70 cm3 or less proved to be better with regards to the dose to the bladder, rectum, and sigmoid.

  8. Source localisation and dose verification for a novel brachytherapy unit

    Science.gov (United States)

    Metaxas, Marinos G.

    A recent development in the field of radiotherapy has been the introduction of the PRS Intrabeam system (Carl Zeiss Surgical GmbH, Oberkochen, Germany). This is essentially a portable, miniaturised, electron-driven photon generator that allows high intensity, soft-energy x-rays (50 kVp) to be delivered directly to the tumour site in a single fraction. The system has been used for the interstitial radiation treatment of both brain and breast tumours. At present, a standardised in-vivo dose verification technique is not available for the PRS treatments. The isotropical distribution of photons about the tip of the PRS probe inserted in the tissue can effectively be viewed as a point source of radiation buried in the body. This work has looked into ways of localising the PRS source utilising its own radiation field. Moreover, the response of monoenergetic sources, mimicking realistic brachytherapy sources, has also been investigated. The purpose of this project was to attempt to localise the source as well as derive important dosimetric information from the resulting image. A detection system comprised of a well-collimated Germanium detector (HPGe) has been devised in a rotate-translate Emission Computed Tomography (ECT) modality. The superior energy resolving ability of the detection system allowed for energy selective reconstruction to be carried out in the case of the monoenergetic source (241Am). Results showed that the monoenergetic source can be localised to within 1 mm and the continuous PRS x-ray source to within 3mm. For the PRS dose map derivation, Monte Carlo studies have been employed in order to extract information on the dosimetric aspect of the resulting image. The final goal of this work was therefore to formulate a direct mathematical relation (Transform Map) between the image created by the escaping photons and the dose map as predicted by the theoretical model. The formation therefore of the in-vivo PRS image could allow for a real-time monitoring

  9. Nanoparticle-Based Brachytherapy Spacers for Delivery of Localized Combined Chemoradiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rajiv, E-mail: r.kumar@neu.edu [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Department of Radiation Oncology, Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts (United States); Belz, Jodi [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Markovic, Stacey [Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts (United States); Jadhav, Tej; Fowle, William [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Niedre, Mark [Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts (United States); Cormack, Robert; Makrigiorgos, Mike G. [Department of Radiation Oncology, Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts (United States); Sridhar, Srinivas [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Department of Radiation Oncology, Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts (United States)

    2015-02-01

    Purpose: In radiation therapy (RT), brachytherapy-inert source spacers are commonly used in clinical practice to achieve high spatial accuracy. These implanted devices are critical technical components of precise radiation delivery but provide no direct therapeutic benefits. Methods and Materials: Here we have fabricated implantable nanoplatforms or chemoradiation therapy (INCeRT) spacers loaded with silica nanoparticles (SNPs) conjugated containing a drug, to act as a slow-release drug depot for simultaneous localized chemoradiation therapy. The spacers are made of poly(lactic-co-glycolic) acid (PLGA) as matrix and are physically identical in size to the commercially available brachytherapy spacers (5 mm × 0.8 mm). The silica nanoparticles, 250 nm in diameter, were conjugated with near infrared fluorophore Cy7.5 as a model drug, and the INCeRT spacers were characterized in terms of size, morphology, and composition using different instrumentation techniques. The spacers were further doped with an anticancer drug, docetaxel. We evaluated the in vivo stability, biocompatibility, and biodegradation of these spacers in live mouse tissues. Results: The electron microscopy studies showed that nanoparticles were distributed throughout the spacers. These INCeRT spacers remained stable and can be tracked by the use of optical fluorescence. In vivo optical imaging studies showed a slow diffusion of nanoparticles from the spacer to the adjacent tissue in contrast to the control Cy7.5-PLGA spacer, which showed rapid disintegration in a few days with a burst release of Cy7.5. The docetaxel spacers showed suppression of tumor growth in contrast to control mice over 16 days. Conclusions: The imaging with the Cy7.5 spacer and therapeutic efficacy with docetaxel spacers supports the hypothesis that INCeRT spacers can be used for delivering the drugs in a slow, sustained manner in conjunction with brachytherapy, in contrast to the rapid clearance of the drugs when

  10. Air core detectors for Cerenkov-free scintillation dosimetry of brachytherapy β-sources.

    Science.gov (United States)

    Eichmann, Marion; Thomann, Benedikt

    2017-09-01

    Plastic scintillation detectors are used for dosimetry in small radiation fields with high dose gradients, e.g., provided by β-emitting sources like (106) Ru/(106) Rh eye plaques. A drawback is a background signal caused by Cerenkov radiation generated by electrons passing the optical fibers (light guides) of this dosimetry system. Common approaches to correct for the Cerenkov signal are influenced by uncertainties resulting from detector positioning and calibration procedures. A different approach to avoid any correction procedure is to suppress the Cerenkov signal by replacing the solid core optical fiber with an air core light guide, previously shown for external beam therapy. In this study, the air core concept is modified and applied to the requirements of dosimetry in brachytherapy, proving its usability for measuring water energy doses in small radiation fields. Three air core detectors with different air core lengths are constructed and their performance in dosimetry for brachytherapy β-sources is compared with a standard two-fiber system, which uses a second fiber for Cerenkov correction. The detector systems are calibrated with a (90) Sr/(90) Y secondary standard and tested for their angular dependence as well as their performance in depth dose measurements of (106) Ru/(106) Rh sources. The signal loss relative to the standard detector increases with increasing air core length to a maximum value of 58.3%. At the same time, however, the percentage amount of Cerenkov light in the total signal is reduced from at least 12.1% to a value below 1.1%. There is a linear correlation between induced dose and measured signal current. The air core detectors determine the dose rates for (106) Ru/(106) Rh sources without any form of correction for the Cerenkov signal. The air core detectors show advantages over the standard two-fiber system especially when measuring in radiation fields with high dose gradients. They can be used as simple one-fiber systems and allow

  11. Dosimetric analysis and comparison of IMRT and HDR brachytherapy in treatment of localized prostate cancer.

    Science.gov (United States)

    Murali, V; Kurup, P G G; Mahadev, P; Mahalakshmi, S

    2010-04-01

    Radical radiotherapy is one of the options for the management of prostate cancer. In external beam therapy, 3D conformal radiotherapy (3DCRT) and intensity modulated radiotherapy (IMRT) are the options for delivery of increased radiation dose, as vital organs are very close to the prostate and a higher dose to these structures leads to an increased toxicity. In brachytherapy, low dose rate brachytherapy with permanent implant of radioactive seeds and high dose rate brachytherapy (HDR) with remote after loaders are available. A dosimetric analysis has been made on IMRT and HDR brachytherapy plans. Ten cases from each IMRT and HDR brachytherapy have been taken for the study. The analysis includes comparison of conformity and homogeneity indices, D100, D95, D90, D80, D50, D10 and D5 of the target. For the organs at risk (OAR), namely rectum and bladder, V100, V90 and V50 are compared. In HDR brachytherapy, the doses to 1 cc and 0.1 cc of urethra have also been studied. Since a very high dose surrounds the source, the 300% dose volumes in the target and within the catheters are also studied in two plans, to estimate the actual volume of target receiving dose over 300%. This study shows that the prescribed dose covers 93 and 92% of the target volume in IMRT and HDR brachytherapy respectively. HDR brachytherapy delivers a much lesser dose to OAR, compared to the IMRT. For rectum, the V50 in IMRT is 34.0cc whilst it is 7.5cc in HDR brachytherapy. With the graphic optimization tool in HDR brachytherapy planning, the dose to urethra could be kept within 120% of the target dose. Hence it is concluded that HDR brachytherapy may be the choice of treatment for cancer of prostate in the early stage.

  12. Dosimetric analysis and comparison of IMRT and HDR brachytherapy in treatment of localized prostate cancer

    Directory of Open Access Journals (Sweden)

    Murali V

    2010-01-01

    Full Text Available Radical radiotherapy is one of the options for the management of prostate cancer. In external beam therapy, 3D conformal radiotherapy (3DCRT and intensity modulated radiotherapy (IMRT are the options for delivery of increased radiation dose, as vital organs are very close to the prostate and a higher dose to these structures leads to an increased toxicity. In brachytherapy, low dose rate brachytherapy with permanent implant of radioactive seeds and high dose rate brachytherapy (HDR with remote after loaders are available. A dosimetric analysis has been made on IMRT and HDR brachytherapy plans. Ten cases from each IMRT and HDR brachytherapy have been taken for the study. The analysis includes comparison of conformity and homogeneity indices, D100, D95, D90, D80, D50, D10 and D5 of the target. For the organs at risk (OAR, namely rectum and bladder, V100, V90 and V50 are compared. In HDR brachytherapy, the doses to 1 cc and 0.1 cc of urethra have also been studied. Since a very high dose surrounds the source, the 300% dose volumes in the target and within the catheters are also studied in two plans, to estimate the actual volume of target receiving dose over 300%. This study shows that the prescribed dose covers 93 and 92% of the target volume in IMRT and HDR brachytherapy respectively. HDR brachytherapy delivers a much lesser dose to OAR, compared to the IMRT. For rectum, the V50 in IMRT is 34.0cc whilst it is 7.5cc in HDR brachytherapy. With the graphic optimization tool in HDR brachytherapy planning, the dose to urethra could be kept within 120% of the target dose. Hence it is concluded that HDR brachytherapy may be the choice of treatment for cancer of prostate in the early stage.

  13. Brachytherapy for prostate cancer: Comparative characteristics of procedures

    Directory of Open Access Journals (Sweden)

    S. V. Kanaev

    2015-01-01

    Full Text Available The introduction of interstitial radiation sources is the «youngest» of the radical method of treatment of patients with prostate cancer (PC. The high level of efficiency comparable to prostatectomy at a significantly lower rate of complications causes rapid growth of clinical use of brachytherapy (BT. Depending on the radiation source and the mode of administration into the prostate gland are two types BT – high-dose rate (temporary (HDR-BT and low-dose rate (permanent (LDR-BT brachytherapy. At the heart of these two methods are based on a single principle of direct effect of the quantum gamma radiation on the area of interest. However, the differences between the characteristics of isotopes used and technical aspects of the techniques cause the difference in performance and complication rates for expression HDR-BT and LDR-BT.

  14. Cataract extraction after brachytherapy for malignant melanoma of the choroid

    Energy Technology Data Exchange (ETDEWEB)

    Fish, G.E.; Jost, B.F.; Snyder, W.I.; Fuller, D.G.; Birch, D.G. (Texas Retina Associates, Dallas (USA))

    1991-05-01

    Thirteen eyes of 55 consecutive patients treated with brachytherapy for malignant melanoma of the choroid developed postirradiation cataracts. Cataract development was more common in older patients and in patients with larger and more anterior tumors. Eleven eyes had extracapsular cataract extraction and intraocular lens implantation. Initial visual improvement occurred in 91% of eyes, with an average improvement of 5.5 lines. Visual acuity was maintained at 20/60 or better in 55% of the eyes over an average period of follow-up of 24 months (range, 6 to 40 months). These data suggest that, visually, cataract extraction can be helpful in selected patients who develop a cataract after brachytherapy for malignant melanoma of the choroid.

  15. Brachytherapy seed localization using geometric and linear programming techniques.

    Science.gov (United States)

    Singh, Vikas; Mukherjee, Lopamudra; Xu, Jinhui; Hoffmann, Kenneth R; Dinu, Petru M; Podgorsak, Matthew

    2007-09-01

    We propose an optimization algorithm to solve the brachytherapy seed localization problem in prostate brachytherapy. Our algorithm is based on novel geometric approaches to exploit the special structure of the problem and relies on a number of key observations which help us formulate the optimization problem as a minimization integer program (IP). Our IP model precisely defines the feasibility polyhedron for this problem using a polynomial number of half-spaces; the solution to its corresponding linear program is rounded to yield an integral solution to our task of determining correspondences between seeds in multiple projection images. The algorithm is efficient in theory as well as in practice and performs well on simulation data (approximately 98% accuracy) and real X-ray images (approximately 95% accuracy). We present in detail the underlying ideas and an extensive set of performance evaluations based on our implementation.

  16. Compound dual radiation action theory for 252Cf brachytherapy.

    Science.gov (United States)

    Wang, C K; Zhang, X

    2004-01-01

    The existing dosimetry protocol that uses the concept of RBE for 252Cf brachytherapy contains large uncertainties. A new formula has been developed to correlate the biological effect (i.e. cell survival fraction) resulting from a mixed n + gamma radiation field with two physical quantities and two biological quantities. The formula is based on a pathway model evolved from that of the compound-dual-radiation-action (CDRA) theory, previously proposed by Rossi and Zaider. The new model employs the recently published data on radiation-induced DNA lesions. The new formula is capable of predicting quantitatively the synergistic effect caused by the interactions between neutron events and gamma ray events, and it is intended to be included into a new dosimetry protocol for future 252Cf brachytherapy.

  17. Dose volume analysis in brachytherapy and stereotactic radiosurgery

    CERN Document Server

    Tozer-Loft, S M

    2000-01-01

    compared with a range of figures of merit which express different aspects of the quality of each dose distributions. The results are analysed in an attempt to answer the question: What are the important features of the dose distribution (conformality, uniformity, etc) which show a definite relationship with the outcome of the treatment? Initial results show positively that, when Gamma Knife radiosurgery is used to treat acoustic neuroma, some measures of conformality seem to have a surprising, but significant association with outcome. A brief introduction to three branches of radiotherapy is given: interstitial brachytherapy, external beam megavoltage radiotherapy, and stereotactic radiosurgery. The current interest in issues around conformity, uniformity and optimisation is explained in the light of technical developments in these fields. A novel method of displaying dose-volume information, which mathematically suppresses the inverse-square law, as first suggested by L.L. Anderson for use in brachytherapy i...

  18. Review of advanced catheter technologies in radiation oncology brachytherapy procedures.

    Science.gov (United States)

    Zhou, Jun; Zamdborg, Leonid; Sebastian, Evelyn

    2015-01-01

    The development of new catheter and applicator technologies in recent years has significantly improved treatment accuracy, efficiency, and outcomes in brachytherapy. In this paper, we review these advances, focusing on the performance of catheter imaging and reconstruction techniques in brachytherapy procedures using magnetic resonance images and electromagnetic tracking. The accuracy of catheter reconstruction, imaging artifacts, and other notable properties of plastic and titanium applicators in gynecologic treatments are reviewed. The accuracy, noise performance, and limitations of electromagnetic tracking for catheter reconstruction are discussed. Several newly developed applicators for accelerated partial breast irradiation and gynecologic treatments are also reviewed. New hypofractionated high dose rate treatment schemes in prostate cancer and accelerated partial breast irradiation are presented.

  19. Distortions induced by radioactive seeds into interstitial brachytherapy dose distributions.

    Science.gov (United States)

    Zhou, Chuanyu; Inanc, Feyzi; Modrick, Joseph M

    2004-12-01

    In a previous article, we presented development and verification of an integral transport equation-based deterministic algorithm for computing three-dimensional brachytherapy dose distributions. Recently, we have included fluorescence radiation physics and parallel computation to the standing algorithms so that we can compute dose distributions for a large set of seeds without resorting to the superposition methods. The introduction of parallel computing capability provided a means to compute the dose distribution for multiple seeds in a simultaneous manner. This provided a way to study strong heterogeneity and shadow effects induced by the presence of multiple seeds in an interstitial brachytherapy implant. This article presents the algorithm for computing fluorescence radiation, algorithm for parallel computing, and display results for an 81-seed implant that has a perfect and imperfect lattice. The dosimetry data for a single model 6711 seeds is presented for verification and heterogeneity factor computations using simultaneous and superposition techniques are presented.

  20. IMAGE-GUIDED RADIOTHERAPY AND -BRACHYTHERAPY FOR CERVICAL CANCER

    Directory of Open Access Journals (Sweden)

    Suresh eDutta

    2015-03-01

    Full Text Available Conventional radiotherapy for cervical cancer relies on clinical examination, 3-dimensional conformal radiotherapy (3D-CRT, and 2-dimensional intracavitary brachytherapy.Excellent local control and survival have been obtained for small early stage cervical cancer with definitive radiotherapy. For bulky and locally advanced disease, the addition of chemotherapy has improved the prognosis but toxicity remains significant. New imaging technology such as positron emission tomography (PET and magnetic resonance imaging (MRI has improved tumor delineation for radiotherapy planning. Image-guided radiotherapy (IGRT may decrease treatment toxicity of whole pelvic radiation because of its potential for bone marrow, bowel, and bladder sparring. Tumor shrinkage during whole pelvic IGRT may optimize image-guided brachytherapy (IGBT, allowing for better local control and reduced toxicity for patients with cervical cancer. IGRT and IGBT should be integrated in future prospective studies for cervical cancer.

  1. 3T MR-Guided Brachytherapy for Gynecologic Malignancies

    CERN Document Server

    Kapur, Tina; Damato, Antonio; Schmidt, Ehud J; Viswanathan, Akila N; 10.1016/j.mri.2012.06.003

    2013-01-01

    Gynecologic malignancies are a leading cause of death in women worldwide. Standard treatment for many primary and recurrent gynecologic cancer cases includes a combination of external beam radiation, followed by brachytherapy. Magnetic Resonance Imaging (MRI) is benefitial in diagnostic evaluation, in mapping the tumor location to tailor radiation dose, and in monitoring the tumor response to treatment. Initial studies of MR-guidance in gynecologic brachtherapy demonstrate the ability to optimize tumor coverage and reduce radiation dose to normal tissues, resulting in improved outcomes for patients. In this article we describe a methodology to aid applicator placement and treatment planning for 3 Tesla (3T) MR-guided brachytherapy that was developed specifically for gynecologic cancers. This has been used in 18 cases to date in the Advanced Multimodality Image Guided Operating suite at Brigham and Women's Hospital. It is comprised of state of the art methods for MR imaging, image analysis, and treatment plann...

  2. Film based verification of calculation algorithms used for brachytherapy planning-getting ready for upcoming challenges of MBDCA

    Directory of Open Access Journals (Sweden)

    Grzegorz Zwierzchowski

    2016-08-01

    Full Text Available Purpose: Well-known defect of TG-43 based algorithms used in brachytherapy is a lack of information about interaction cross-sections, which are determined not only by electron density but also by atomic number. TG-186 recommendations with using of MBDCA (model-based dose calculation algorithm, accurate tissues segmentation, and the structure’s elemental composition continue to create difficulties in brachytherapy dosimetry. For the clinical use of new algorithms, it is necessary to introduce reliable and repeatable methods of treatment planning systems (TPS verification. The aim of this study is the verification of calculation algorithm used in TPS for shielded vaginal applicators as well as developing verification procedures for current and further use, based on the film dosimetry method. Material and methods : Calibration data was collected by separately irradiating 14 sheets of Gafchromic® EBT films with the doses from 0.25 Gy to 8.0 Gy using HDR 192Ir source. Standard vaginal cylinders of three diameters were used in the water phantom. Measurements were performed without any shields and with three shields combination. Gamma analyses were performed using the VeriSoft® package. Results : Calibration curve was determined as third-degree polynomial type. For all used diameters of unshielded cylinder and for all shields combinations, Gamma analysis were performed and showed that over 90% of analyzed points meets Gamma criteria (3%, 3 mm. Conclusions : Gamma analysis showed good agreement between dose distributions calculated using TPS and measured by Gafchromic films, thus showing the viability of using film dosimetry in brachytherapy.

  3. egs_brachy: a versatile and fast Monte Carlo code for brachytherapy

    Science.gov (United States)

    Chamberland, Marc J. P.; Taylor, Randle E. P.; Rogers, D. W. O.; Thomson, Rowan M.

    2016-12-01

    egs_brachy is a versatile and fast Monte Carlo (MC) code for brachytherapy applications. It is based on the EGSnrc code system, enabling simulation of photons and electrons. Complex geometries are modelled using the EGSnrc C++ class library and egs_brachy includes a library of geometry models for many brachytherapy sources, in addition to eye plaques and applicators. Several simulation efficiency enhancing features are implemented in the code. egs_brachy is benchmarked by comparing TG-43 source parameters of three source models to previously published values. 3D dose distributions calculated with egs_brachy are also compared to ones obtained with the BrachyDose code. Well-defined simulations are used to characterize the effectiveness of many efficiency improving techniques, both as an indication of the usefulness of each technique and to find optimal strategies. Efficiencies and calculation times are characterized through single source simulations and simulations of idealized and typical treatments using various efficiency improving techniques. In general, egs_brachy shows agreement within uncertainties with previously published TG-43 source parameter values. 3D dose distributions from egs_brachy and BrachyDose agree at the sub-percent level. Efficiencies vary with radionuclide and source type, number of sources, phantom media, and voxel size. The combined effects of efficiency-improving techniques in egs_brachy lead to short calculation times: simulations approximating prostate and breast permanent implant (both with (2 mm)3 voxels) and eye plaque (with (1 mm)3 voxels) treatments take between 13 and 39 s, on a single 2.5 GHz Intel Xeon E5-2680 v3 processor core, to achieve 2% average statistical uncertainty on doses within the PTV. egs_brachy will be released as free and open source software to the research community.

  4. History of dose specification in Brachytherapy: From Threshold Erythema Dose to Computational Dosimetry

    Science.gov (United States)

    Williamson, Jeffrey F.

    2006-09-01

    This paper briefly reviews the evolution of brachytherapy dosimetry from 1900 to the present. Dosimetric practices in brachytherapy fall into three distinct eras: During the era of biological dosimetry (1900-1938), radium pioneers could only specify Ra-226 and Rn-222 implants in terms of the mass of radium encapsulated within the implanted sources. Due to the high energy of its emitted gamma rays and the long range of its secondary electrons in air, free-air chambers could not be used to quantify the output of Ra-226 sources in terms of exposure. Biological dosimetry, most prominently the threshold erythema dose, gained currency as a means of intercomparing radium treatments with exposure-calibrated orthovoltage x-ray units. The classical dosimetry era (1940-1980) began with successful exposure standardization of Ra-226 sources by Bragg-Gray cavity chambers. Classical dose-computation algorithms, based upon 1-D buildup factor measurements and point-source superposition computational algorithms, were able to accommodate artificial radionuclides such as Co-60, Ir-192, and Cs-137. The quantitative dosimetry era (1980- ) arose in response to the increasing utilization of low energy K-capture radionuclides such as I-125 and Pd-103 for which classical approaches could not be expected to estimate accurate correct doses. This led to intensive development of both experimental (largely TLD-100 dosimetry) and Monte Carlo dosimetry techniques along with more accurate air-kerma strength standards. As a result of extensive benchmarking and intercomparison of these different methods, single-seed low-energy radionuclide dose distributions are now known with a total uncertainty of 3%-5%.

  5. Brachytherapy in Lip Carcinoma: Long-Term Results

    Energy Technology Data Exchange (ETDEWEB)

    Guibert, Mireille, E-mail: mireilleguib@voila.fr [Department of Head and Neck Surgery, Larrey Hospital, Toulouse (France); David, Isabelle [Department of Radiation Oncology, Claudius Regaud Institut, Toulouse (France); Vergez, Sebastien [Department of Head and Neck Surgery, Larrey Hospital, Toulouse (France); Rives, Michel [Department of Radiation Oncology, Claudius Regaud Institut, Toulouse (France); Filleron, Thomas [Department of Epidemiology, Claudius Regaud Institut, Toulouse (France); Bonnet, Jacques; Delannes, Martine [Department of Radiation Oncology, Claudius Regaud Institut, Toulouse (France)

    2011-12-01

    Purpose: The aim of this study was to evaluate the effectiveness of low-dose-rate brachytherapy for local control and relapse-free survival in squamous cell and basal cell carcinomas of the lips. We compared two groups: one with tumors on the skin and the other with tumors on the lip. Patients and methods: All patients had been treated at Claudius Regaud Cancer Centre from 1990 to 2008 for squamous cell or basal cell carcinoma. Low-dose-rate brachytherapy was performed with iridium 192 wires according to the Paris system rules. On average, the dose delivered was 65 Gy. Results: 172 consecutive patients were included in our study; 69 had skin carcinoma (squamous cell or basal cell), and 92 had squamous cell mucosal carcinoma. The average follow-up time was 5.4 years. In the skin cancer group, there were five local recurrences and one lymph node recurrence. In the mucosal cancer group, there were ten local recurrences and five lymph node recurrences. The 8-year relapse-free survival for the entire population was 80%. The 8-year relapse-free survival was 85% for skin carcinoma 75% for mucosal carcinoma, with no significant difference between groups. The functional results were satisfactory for 99% of patients, and the cosmetic results were satisfactory for 92%. Maximal toxicity observed was Grade 2. Conclusions: Low-dose-rate brachytherapy can be used to treat lip carcinomas at Stages T1 and T2 as the only treatment with excellent results for local control and relapse-free survival. The benefits of brachytherapy are also cosmetic and functional, with 91% of patients having no side effects.

  6. Study of two different radioactive sources for prostate brachytherapy treatment

    Energy Technology Data Exchange (ETDEWEB)

    Pereira Neves, Lucio; Perini, Ana Paula [Instituto de Fisica, Universidade Federal de Uberlandia, Caixa Postal 593, 38400-902, Uberlandia, MG (Brazil); Souza Santos, William de; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares, Comissao Nacional de Energia Nuclear, IPENCNEN/SP, Av. Prof. Lineu Prestes, 2242, Cidade Universitaria, 05508-000 Sao Paulo, SP (Brazil); Belinato, Walmir [Departamento de Ensino, Instituto Federal de Educacao, Ciencia e Tecnologia da Bahia, Campus Vitoria da Conquista, Zabele, Av. Amazonas 3150, 45030-220 Vitoria da Conquista, BA (Brazil)

    2015-07-01

    In this study we evaluated two radioactive sources for brachytherapy treatments. Our main goal was to quantify the absorbed doses on organs and tissues of an adult male patient, submitted to a brachytherapy treatment with two radioactive sources. We evaluated a {sup 192}Ir and a {sup 125}I radioactive sources. The {sup 192}Ir radioactive source is a cylinder with 0.09 cm in diameter and 0.415 cm long. The {sup 125}I radioactive source is also a cylinder, with 0.08 cm in diameter and 0.45 cm long. To evaluate the absorbed dose distribution on the prostate, and other organs and tissues of an adult man, a male virtual anthropomorphic phantom MASH, coupled in the radiation transport code MCNPX 2.7.0, was employed.We simulated 75, 90 and 102 radioactive sources of {sup 125}I and one of {sup 192}Ir, inside the prostate, as normally used in these treatments, and each treatment was simulated separately. As this phantom was developed in a supine position, the displacement of the internal organs of the chest, compression of the lungs and reduction of the sagittal diameter were all taken into account. For the {sup 192}Ir, the higher doses values were obtained for the prostate and surrounding organs, as the colon, gonads and bladder. Considering the {sup 125}I sources, with photons with lower energies, the doses to organs that are far from the prostate were lower. All values for the dose rates are in agreement with those recommended for brachytherapy treatments. Besides that, the new seeds evaluated in this work present usefulness as a new tool in prostate brachytherapy treatments, and the methodology employed in this work may be applied for other radiation sources, or treatments. (authors)

  7. Surgical management of strabismus following choroidal melanoma plaque brachytherapy.

    Science.gov (United States)

    Alfreihi, Shatha H; Pineles, Stacy L; McCannel, Tara A; Prada, Angelica M; Velez, Federico G

    2017-08-01

    To characterize intraoperative findings, surgical approach, and postoperative outcomes in patients undergoing strabismus surgery following plaque brachytherapy for ocular melanoma. The records of all patients who underwent plaque brachytherapy for choroidal melanoma between May 2007 and June 2016 were reviewed retrospectively to identify those who subsequently required strabismus surgery. Of the 461 patients who underwent plaque brachytherapy during the study period, 13 (2.8%) met inclusion criteria. Visual acuity of the affected eye was 20/40 or better in 9 patients (69%). Preoperative horizontal deviation ranged from 0(Δ) to 52(Δ); vertical deviation, from 2(Δ) to 25(Δ). At final follow-up mean horizontal deviation ranged from 0 to 4(Δ); vertical deviation, from 0(Δ) to 12(Δ). Intraoperatively, all muscles directly adjacent to the treated area appeared macroscopically thicker than normal despite being functionally underacting. Magnetic resonance imaging showed enlarged muscles adjacent to the plaque radiotherapy. Microscopic examination of muscles in 2 patients showed reactive enlargement of the muscle fibers, granulation tissue, and inflammation. Persistent strabismus after plaque brachytherapy is rare. Typical findings include enlarged, underacting rectus muscles adjacent to the area of the plaque, restrictive connective tissue, and incomitant strabismus. Previously disinserted muscles may be found in abnormal locations. In this patient cohort scar tissue removal in conjunction with tightening procedures on the muscle adjacent to the plaque combined with recession of the antagonist muscle frequently resulted in good anatomical outcome. Copyright © 2017 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  8. Ruby-based inorganic scintillation detectors for 192Ir brachytherapy

    Science.gov (United States)

    Kertzscher, Gustavo; Beddar, Sam

    2016-11-01

    We tested the potential of ruby inorganic scintillation detectors (ISDs) for use in brachytherapy and investigated various unwanted luminescence properties that may compromise their accuracy. The ISDs were composed of a ruby crystal coupled to a poly(methyl methacrylate) fiber-optic cable and a charge-coupled device camera. The ISD also included a long-pass filter that was sandwiched between the ruby crystal and the fiber-optic cable. The long-pass filter prevented the Cerenkov and fluorescence background light (stem signal) induced in the fiber-optic cable from striking the ruby crystal, which generates unwanted photoluminescence rather than the desired radioluminescence. The relative contributions of the radioluminescence signal and the stem signal were quantified by exposing the ruby detectors to a high-dose-rate brachytherapy source. The photoluminescence signal was quantified by irradiating the fiber-optic cable with the detector volume shielded. Other experiments addressed time-dependent luminescence properties and compared the ISDs to commonly used organic scintillator detectors (BCF-12, BCF-60). When the brachytherapy source dwelled 0.5 cm away from the fiber-optic cable, the unwanted photoluminescence was reduced from  >5% to  5% within 10 s from the onset of irradiation and after the source had retracted. The ruby-based ISDs generated signals of up to 20 times that of BCF-12-based detectors. The study presents solutions to unwanted luminescence properties of ruby-based ISDs for high-dose-rate brachytherapy. An optic filter should be sandwiched between the ruby crystal and the fiber-optic cable to suppress the photoluminescence. Furthermore, we recommend avoiding ruby crystals that exhibit significant time-dependent luminescence.

  9. Scintillating fiber optic dosimeters for breast and prostate brachytherapy

    Science.gov (United States)

    Moutinho, L. M.; Castro, I. F.; Freitas, H.; Melo, J.; Silva, P.; Gonçalves, A.; Peralta, L.; Rachinhas, P. J.; Simões, P. C. P. S.; Pinto, S.; Pereira, A.; Santos, J. A. M.; Costa, M.; Veloso, J. F. C. A.

    2017-02-01

    Brachytherapy is a radiotherapy modality where the radioactive material is placed close to the tumor, being a common treatment for skin, breast, gynecological and prostate cancers. These treatments can be of low-dose-rate, using isotopes with mean energy of 30 keV, or high-dose-rate, using isotopes such as 192Ir with a mean energy of 380 keV. Currently these treatments are performed in most cases without in-vivo dosimetry for quality control and quality assurance. We developed a dosimeter using small diameter probes that can be inserted into the patient's body using standard brachytherapy needles. By performing real-time dosimetry in breast and prostate brachytherapy it will be possible to perform real-time dose correction when deviations from the treatment plan are observed. The dosimeter presented in this work was evaluated in-vitro. The studies consisted in the characterization of the dosimeter with 500 μm diameter sensitive probes (with a BCF-12 scintillating optical fiber) using an inhouse made gelatin breast phantom with a volume of 566 cm3. A breast brachytherapy treatment was simulated considering a tumor volume of 27 cm3 and a prescribed absolute dose of 5 Gy. The dose distribution was determined by the Inverse Planning Simulated Annealing (IPSA) optimization algorithm (ELEKTA). The dwell times estimated from the experimental measurements are in agreement with the prescribed dwell times, with relative error below 3%. The measured signal-to-noise ratio (SNR) including the stem-effect contribution is below 3%.

  10. Stereolithographic modelling as an aid to orbital brachytherapy.

    Science.gov (United States)

    Poulsen, M; Lindsay, C; Sullivan, T; D'Urso, P

    1999-06-01

    This paper describes the technique of stereolithographic biomodelling and its application to a patient who was treated using orbital brachytherapy. The process uses a moving laser beam, directed by a computer, to draw cross-sections of the model onto the surface of photo-curable liquid plastic. Using a stereolithographic apparatus (SLA), solid or surface data is sliced by software into very thin cross-sections. A helium cadmium (HeCd) laser then generates a small intense spot of ultraviolet (UV) light that is moved across the top of a vat of liquid photo monomer by a computerised optical scanning system. The laser polymerises the liquid into a solid where it touches, precisely printing each cross-section. A vertical elevator lowers the newly formed layer, and a recoating and levelling system establishes the next layer's thickness. Successive cross-sections (0.25 mm thick), each one adhering to the one below, are built one on top of the other, to form the part from the bottom up. The biomodel allowed the implant to be planned in detail prior to the surgery. The accurate placement of brachytherapy catheters was assured, and the dosimetry could be determined and optimised prior to the definitive procedure. Stereolithography is a useful technique in the area of orbital brachytherapy. It allows the implant to to be carried out with greater accuracy and confidence. For the patient, it minimises the risk to the eye and provides them with a greater understanding of the procedure.

  11. Image-guided high dose rate endorectal brachytherapy.

    Science.gov (United States)

    Devic, Slobodan; Vuong, Té; Moftah, Belal; Evans, Michael; Podgorsak, Ervin B; Poon, Emily; Verhaegen, Frank

    2007-11-01

    Fractionated high dose rate endorectal brachytherapy (HDR-EBT) using CT-based treatment planning is an alternative method for preoperative down-sizing and down-staging of advanced rectal adeno-carcinomas. The authors present an image guidance procedure that was developed to ensure daily dose reproducibility for the four brachytherapy treatment fractions. Since the applicator might not be placed before each treatment fraction inside the rectal lumen in the same manner as it was placed during the 3D CT volume acquisition used for treatment planning, there is a shift along the catheter axis that may have to be performed. The required shift is determined by comparison of a daily radiograph with the treatment planning digitally-reconstructed radiograph (DRR). A procedure is developed for DRR reconstruction from the 3D data set used for the treatment planning, and two possible daily longitudinal shifts are illustrated: above and below the planning dose distribution. The authors also describe the procedure for rotational alignment illustrated on a clinical case. Reproduction of the treatment planned dose distribution on a daily basis is crucial for the success of fractionated 3D based brachytherapy treatments. Due to the cylindrical symmetry of the applicator used for preoperative HDR-EBT, two types of adjustments are necessary: applicator rotation and dwell position shift along the applicator's longitudinal axis. The impact of the longitudinal applicator shift prior to treatment delivery for 62 patients treated in our institution is also assessed.

  12. Fabrication of cesium-137 brachytherapy sources using vitrification technology.

    Science.gov (United States)

    Dash, Ashutosh; Varma, R N; Ram, Ramu; Saxena, S K; Mathakar, A R; Avhad, B G; Sastry, K V S; Sangurdekar, P R; Venkatesh, Meera

    2009-08-01

    137Cs source in solid matrix encapsulated in stainless-steel at MBq (mCi) levels are widely used as brachytherapy sources for the treatment of carcinoma of cervix uteri. This article describes the large-scale preparation of such sources. The process of fabrication includes vitrification of 137Cs-sodium borosilicate glass, its transformation into spheres of 5-6 mm diameter, casting of glass spheres into a cylinder of 1.5 mm (varphi) x 80 mm (l) in a platinum mould, cutting of the moulds into 5-mm-long pieces, silver coating on the sources, and finally, encapsulation in stainless steel capsules. Development of safety precautions used to trap 137Cs escaping during borosilicate glass preparation is also described. The leach rates of the radioactive sources prepared by the above technology were within permissible limits, and the sources could be used for encapsulation in stainless steel capsules and supplied for brachytherapy applications. This development was aimed at promoting the potential utility of 137Cs-brachytherapy sources in the country and reducing the user's reliance on imported sources. Since its development, more than 1000 such sources have been made by using 4.66 TBq(126 Ci) of 137Cs.

  13. A compilation of current regulations, standards and guidelines in remote afterloading brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Tortorelli, J.P.; Simion, G.P.; Kozlowski, S.D. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1994-10-01

    Over a dozen government and professional organizations in the United States and Europe have issued regulations and guidance concerning quality management in the practice of remote afterloading brachytherapy. Information from the publications of these organizations was collected and collated for this report. This report provides the brachytherapy licensee access to a broad field of quality management information in a single, topically organized document.

  14. Salvage high-dose-rate brachytherapy for isolated vaginal recurrence of endometrial cancer.

    Science.gov (United States)

    Baek, Sungjae; Isohashi, Fumiaki; Yamaguchi, Hiroko; Mabuchi, Seiji; Yoshida, Ken; Kotsuma, Tadayuki; Yamazaki, Hideya; Tanaka, Eiichi; Sumida, Iori; Tamari, Keisuke; Otani, Keisuke; Seo, Yuji; Suzuki, Osamu; Yoshioka, Yasuo; Kimura, Tadashi; Ogawa, Kazuhiko

    We have retrospectively analyzed the outcomes of high-dose-rate (HDR) brachytherapy as a salvage therapy for vaginal recurrence of endometrial cancer. From 1997 to 2012, salvage HDR brachytherapy was performed in 43 patients. The median age was 64 years (range, 41-88 years). HDR brachytherapy was performed by interstitial brachytherapy in 34 patients (79%) and by intracavity brachytherapy in nine patients (21%). Seventeen (40%) of the 43 patients were treated with external beam radiotherapy. The median followup period was 58 months (range, 6-179 months). The 5-year overall survival (OS), progression-free survival (PFS), and local control rates (LC) were 84%, 52%, and 78%, respectively. Patients who received brachytherapy with external beam radiotherapy experienced no nodal recurrence (0 of 17 patients), whereas 23% of the patients (6 of 26 patients) who received brachytherapy alone experienced nodal recurrence (p = 0.047). The pathologic grade at the time of initial surgery (G1-2 vs. G3) was found to be a significant prognostic factor for both OS and PFS. The respective 5-year OS was 96% vs. 40% (p endometrial cancer. Pathologic grade, age, and modality were significant prognostic factors. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  15. ALGEBRA: ALgorithm for the heterogeneous dosimetry based on GEANT4 for BRAchytherapy.

    Science.gov (United States)

    Afsharpour, H; Landry, G; D'Amours, M; Enger, S; Reniers, B; Poon, E; Carrier, J-F; Verhaegen, F; Beaulieu, L

    2012-06-07

    Task group 43 (TG43)-based dosimetry algorithms are efficient for brachytherapy dose calculation in water. However, human tissues have chemical compositions and densities different than water. Moreover, the mutual shielding effect of seeds on each other (interseed attenuation) is neglected in the TG43-based dosimetry platforms. The scientific community has expressed the need for an accurate dosimetry platform in brachytherapy. The purpose of this paper is to present ALGEBRA, a Monte Carlo platform for dosimetry in brachytherapy which is sufficiently fast and accurate for clinical and research purposes. ALGEBRA is based on the GEANT4 Monte Carlo code and is capable of handling the DICOM RT standard to recreate a virtual model of the treated site. Here, the performance of ALGEBRA is presented for the special case of LDR brachytherapy in permanent prostate and breast seed implants. However, the algorithm is also capable of handling other treatments such as HDR brachytherapy.

  16. Dosimetry Modeling for Focal Low-Dose-Rate Prostate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Al-Qaisieh, Bashar [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Mason, Josh, E-mail: joshua.mason@nhs.net [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Bownes, Peter; Henry, Ann [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Dickinson, Louise [Division of Surgery and Interventional Science, University College London, London (United Kingdom); Department of Radiology, Northwick Park Hospital, London North West NHS Trust, London (United Kingdom); Ahmed, Hashim U. [Division of Surgery and Interventional Science, University College London, London (United Kingdom); University College London Hospital, London (United Kingdom); Emberton, Mark [University College London Hospital, London (United Kingdom); Langley, Stephen [St Luke' s Cancer Centre, Guildford (United Kingdom)

    2015-07-15

    Purpose: Focal brachytherapy targeted to an individual lesion(s) within the prostate may reduce side effects experienced with whole-gland brachytherapy. The outcomes of a consensus meeting on focal prostate brachytherapy were used to investigate optimal dosimetry of focal low-dose-rate (LDR) prostate brachytherapy targeted using multiparametric magnetic resonance imaging (mp-MRI) and transperineal template prostate mapping (TPM) biopsy, including the effects of random and systematic seed displacements and interseed attenuation (ISA). Methods and Materials: Nine patients were selected according to clinical characteristics and concordance of TPM and mp-MRI. Retrospectively, 3 treatment plans were analyzed for each case: whole-gland (WG), hemi-gland (hemi), and ultra-focal (UF) plans, with 145-Gy prescription dose and identical dose constraints for each plan. Plan robustness to seed displacement and ISA were assessed using Monte Carlo simulations. Results: WG plans used a mean 28 needles and 81 seeds, hemi plans used 17 needles and 56 seeds, and UF plans used 12 needles and 25 seeds. Mean D90 (minimum dose received by 90% of the target) and V100 (percentage of the target that receives 100% dose) values were 181.3 Gy and 99.8% for the prostate in WG plans, 195.7 Gy and 97.8% for the hemi-prostate in hemi plans, and 218.3 Gy and 99.8% for the focal target in UF plans. Mean urethra D10 was 205.9 Gy, 191.4 Gy, and 92.4 Gy in WG, hemi, and UF plans, respectively. Mean rectum D2 cm{sup 3} was 107.5 Gy, 77.0 Gy, and 42.7 Gy in WG, hemi, and UF plans, respectively. Focal plans were more sensitive to seed displacement errors: random shifts with a standard deviation of 4 mm reduced mean target D90 by 14.0%, 20.5%, and 32.0% for WG, hemi, and UF plans, respectively. ISA has a similar impact on dose-volume histogram parameters for all plan types. Conclusions: Treatment planning for focal LDR brachytherapy is feasible. Dose constraints are easily met with a notable

  17. Third-party brachytherapy source calibrations and physicist responsibilities: report of the AAPM Low Energy Brachytherapy Source Calibration Working Group.

    Science.gov (United States)

    Butler, Wayne M; Bice, William S; DeWerd, Larry A; Hevezi, James M; Huq, M Saiful; Ibbott, Geoffrey S; Palta, Jatinder R; Rivard, Mark J; Seuntjens, Jan P; Thomadsen, Bruce R

    2008-09-01

    The AAPM Low Energy Brachytherapy Source Calibration Working Group was formed to investigate and recommend quality control and quality assurance procedures for brachytherapy sources prior to clinical use. Compiling and clarifying recommendations established by previous AAPM Task Groups 40, 56, and 64 were among the working group's charges, which also included the role of third-party handlers to perform loading and assay of sources. This document presents the findings of the working group on the responsibilities of the institutional medical physicist and a clarification of the existing AAPM recommendations in the assay of brachytherapy sources. Responsibility for the performance and attestation of source assays rests with the institutional medical physicist, who must use calibration equipment appropriate for each source type used at the institution. Such equipment and calibration procedures shall ensure secondary traceability to a national standard. For each multi-source implant, 10% of the sources or ten sources, whichever is greater, are to be assayed. Procedures for presterilized source packaging are outlined. The mean source strength of the assayed sources must agree with the manufacturer's stated strength to within 3%, or action must be taken to resolve the difference. Third party assays do not absolve the institutional physicist from the responsibility to perform the institutional measurement and attest to the strength of the implanted sources. The AAPM leaves it to the discretion of the institutional medical physicist whether the manufacturer's or institutional physicist's measured value should be used in performing dosimetry calculations.

  18. Ocular Response of Choroidal Melanoma With Monosomy 3 Versus Disomy 3 After Iodine-125 Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Marathe, Omkar S. [David Geffen School of Medicine, University of Los Angeles, Los Angeles, CA (United States); Wu, Jeffrey; Lee, Steve P. [Department of Radiation Oncology, University of Los Angeles, Los Angeles, CA (United States); Yu Fei; Burgess, Barry L. [Department of Ophthalmology, The Jules Stein Eye Institute, University of Los Angeles, Los Angeles, CA (United States); Leu Min [Department of Radiation Oncology, University of Los Angeles, Los Angeles, CA (United States); Straatsma, Bradley R. [Department of Ophthalmology, The Jules Stein Eye Institute, University of Los Angeles, Los Angeles, CA (United States); McCannel, Tara A., E-mail: TMcCannel@jsei.ucla.edu [Department of Ophthalmology, Jules Stein Eye Institute, University of Los Angeles, Los Angeles, CA (United States); Jonsson Comprehensive Cancer Center, University of Los Angeles, Los Angeles, CA (United States)

    2011-11-15

    Purpose: To report the ocular response of choroidal melanoma with monosomy 3 vs. disomy 3 after {sup 125}I brachytherapy. Methods and Materials: We evaluated patients with ciliochoroidal melanoma managed with fine needle aspiration biopsy immediately before plaque application for {sup 125}I brachytherapy between January 1, 2005 and December 31, 2008. Patients with (1) cytopathologic diagnosis of melanoma, (2) melanoma chromosome 3 status identified by fluorescence in situ hybridization, and (3) 6 or more months of follow-up after brachytherapy were sorted by monosomy 3 vs. disomy 3 and compared by Kruskal-Wallis test. Results: Among 40 ciliochoroidal melanomas (40 patients), 15 had monosomy 3 and 25 had disomy 3. Monosomy 3 melanomas had a median greatest basal diameter of 12.00 mm and a median tumor thickness of 6.69 mm before brachytherapy; at a median of 1.75 years after brachytherapy, median thickness was 3.10 mm. Median percentage decrease in tumor thickness was 48.3%. Disomy 3 melanomas had a median greatest basal diameter of 10.00 mm and median tumor thickness of 3.19 mm before brachytherapy; at a median of 2.00 years after brachytherapy, median tumor thickness was 2.37 mm. The median percentage decrease in tumor thickness was 22.7%. Monosomy 3 melanomas were statistically greater in size than disomy 3 melanomas (p < 0.001) and showed a greater decrease in tumor thickness after brachytherapy (p = 0.006). Conclusion: In this study, ciliochoroidal melanomas with monosomy 3 were significantly greater in size than disomy 3 melanoma and showed a significantly greater decrease in thickness at a median of 1.75 years after brachytherapy. The greater decrease in monosomy 3 melanoma thickness after brachytherapy is consistent with other malignancies in which more aggressive pathology has been shown to be associated with a greater initial response to radiotherapy.

  19. Accelerated Partial Breast Irradiation (APBI: A review of available techniques

    Directory of Open Access Journals (Sweden)

    Saunders Mark W

    2010-10-01

    Full Text Available Abstract Breast conservation therapy (BCT is the procedure of choice for the management of the early stage breast cancer. However, its utilization has not been maximized because of logistics issues associated with the protracted treatment involved with the radiation treatment. Accelerated Partial Breast Irradiation (APBI is an approach that treats only the lumpectomy bed plus a 1-2 cm margin, rather than the whole breast. Hence because of the small volume of irradiation a higher dose can be delivered in a shorter period of time. There has been growing interest for APBI and various approaches have been developed under phase I-III clinical studies; these include multicatheter interstitial brachytherapy, balloon catheter brachytherapy, conformal external beam radiation therapy and intra-operative radiation therapy (IORT. Balloon-based brachytherapy approaches include Mammosite, Axxent electronic brachytherapy and Contura, Hybrid brachytherapy devices include SAVI and ClearPath. This paper reviews the different techniques, identifying the weaknesses and strength of each approach and proposes a direction for future research and development. It is evident that APBI will play a role in the management of a selected group of early breast cancer. However, the relative role of the different techniques is yet to be clearly identified.

  20. Investigation of Dosimetric Parameters of $^{192}$Ir MicroSelectron v2 HDR Brachytherapy Source Using EGSnrc Monte Carlo Code

    CERN Document Server

    Naeem, Hamza; Zheng, Huaqing; Cao, Ruifen; Pei, Xi; Hu, Liqin; Wu, Yican

    2016-01-01

    The $^{192}$Ir sources are widely used for high dose rate (HDR) brachytherapy treatments. The aim of this study is to simulate $^{192}$Ir MicroSelectron v2 HDR brachytherapy source and calculate the air kerma strength, dose rate constant, radial dose function and anisotropy function established in the updated AAPM Task Group 43 protocol. The EGSnrc Monte Carlo (MC) code package is used to calculate these dosimetric parameters, including dose contribution from secondary electron source and also contribution of bremsstrahlung photons to air kerma strength. The Air kerma strength, dose rate constant and radial dose function while anisotropy functions for the distance greater than 0.5 cm away from the source center are in good agreement with previous published studies. Obtained value from MC simulation for air kerma strength is $9.762\\times 10^{-8} \\textrm{UBq}^{-1}$and dose rate constant is $1.108\\pm 0.13\\%\\textrm{cGyh}^{-1} \\textrm{U}^{-1}$.

  1. Electromagnetically navigated brachytherapy as a new treatment option for peripheral pulmonary tumors.

    Science.gov (United States)

    Harms, Wolfgang; Krempien, Robert; Grehn, Christian; Hensley, Frank; Debus, Jürgen; Becker, Heinrich D

    2006-02-01

    This technical note describes the principles of navigated brachytherapy for treatment of peripheral non-small cell lung cancer (NSCLC). In a prospective feasibility trial a first patient with medically inoperable NSCLC in the right upper lobe was treated with external-beam radiotherapy (50 Gy) and navigated endoluminal brachytherapy (15 Gy). Navigated bronchoscopy was performed with an electromagnetic navigation system for localization of a microsensor mounted on the tip of a dedicated catheter placed within the working channel of a bronchoscope. The probe can be actively guided by a steering mechanism to targeted lesions in the periphery of the lung. After successful localization of the NSCLC, endobronchial ultrasound (EBUS) was performed to confirm the exact position in the center of the lesion. A 6-F brachytherapy catheter was placed within the tumor. Primary 3-D-planned brachytherapy was performed on chest CTs acquired with the inserted catheter. High-dose-rate brachytherapy (370 GBq iridium-192) was applied as a boost three times a week (single dose 5 Gy) and provided highly conformal irradiations of the NSCLC including the draining bronchovascular bundle. The brachytherapy catheter was tolerated well during treatment (5 days) and alimentation was possible without any problems. Repeated CTs showed stable positioning of the catheter. During follow-up (12 months), endoluminal ultrasound and CT demonstrated a partial remission while histology showed a complete remission of the tumor. Navigated brachytherapy for peripheral pulmonary tumors not amenable to conventional bronchoscopy is feasible.

  2. Electromagnetically navigated brachytherapy as a new treatment option for peripheral pulmonary tumors

    Energy Technology Data Exchange (ETDEWEB)

    Harms, W.; Krempien, R.; Grehn, C.; Hensley, F.; Debus, J. [Dept. of Radio-Oncology, Univ. of Heidelberg (Germany); Becker, H.D. [Dept. of Interdisciplinary Bronchoscopy, Thorax Clinic at Heidelberg Univ. Medical School, Heidelberg (Germany)

    2006-02-01

    Purpose: this technical note describes the principles of navigated brachytherapy for treatment of peripheral non-small cell lung cancer (NSCLC). Material and methods: in a prospective feasibility trial a first patient with medically inoperable NSCLC in the right upper lobe was treated with external-beam radiotherapy (50 Gy) and navigated endoluminal brachytherapy (15 Gy). Navigated bronchoscopy was performed with an electromagnetic navigation system for localization of a microsensor mounted on the tip of a dedicated catheter placed within the working channel of a bronchoscope. The probe can be actively guided by a steering mechanism to targeted lesions in the periphery of the lung. After successful localization of the NSCLC, endobronchial ultrasound (EBUS) was performed to confirm the exact position in the center of the lesion. A 6-F brachytherapy catheter was placed within the tumor. Primary 3-D-planned brachytherapy was performed on chest CTs acquired with the inserted catheter. High-dose-rate brachytherapy (370 GBq iridium-192) was applied as a boost three times a week (single dose 5 Gy) and provided highly conformal irradiations of the NSCLC including the draining bronchovascular bundle. Results: the brachytherapy catheter was tolerated well during treatment (5 days) and alimentation was possible without any problems. Repeated CTs showed stable positioning of the catheter. During follow-up (12 months), endoluminal ultrasound and CT demonstrated a partial remission while histology showed a complete remission of the tumor. Conclusion: navigated brachytherapy for peripheral pulmonary tumors not amenable to conventional bronchoscopy is feasible. (orig.)

  3. Interstitial brachytherapy for eyelid carcinoma. Outcome analysis in 60 patients

    Energy Technology Data Exchange (ETDEWEB)

    Krengli, M.; Deantonio, L. [University Hospital ' ' Maggiore della Carita' ' , Division of Radiotherapy, Novara (Italy); University of ' ' Piemonte Orientale' ' , Department of Translational Medicine, Novara (Italy); Masini, L.; Filomeno, A.; Gambaro, G. [University Hospital ' ' Maggiore della Carita' ' , Division of Radiotherapy, Novara (Italy); Comoli, A.M. [University Hospital Maggiore della Carita, Ophthalmology, Novara (Italy); Negri, E. [University Hospital Maggiore della Carita, Medical Physics, Novara (Italy)

    2014-03-15

    Eyelid cancer is a therapeutic challenge due to the cosmetic and functional implications of this anatomical region and the objectives of therapy are tumor control, functional and cosmetic outcome. The present study was performed to analyze local control, toxicity, functional and cosmetic results in patients with eyelid carcinoma treated by interstitial brachytherapy. In this study 60 patients with eyelid carcinoma were treated by interstitial brachytherapy using iridium ({sup 192}Ir) wires with a linear activity of 1.2-1.7 mCi/cm. The prescription dose was 51-70 Gy (mean 65 Gy, median 66 Gy). Of the 60 patients 51 (85.0 %) had received no prior treatment, 4 (6.7 %) had received previous surgery with positive or close margins and 5 (8.3 %) had suffered local recurrence after surgery. Of the tumors 52 (86.7 %) were basal cell carcinoma, 7 (11.7 %) squamous cell carcinoma and 1 (1.7 %) Merkel cell carcinoma. Clinical stage of the 51 previously untreated tumors was 38 T1N0, 12 T2N0 and 1 T3N0. Mean follow-up was 92 months (range 6-253 months). Local control was maintained in 96.7 % of patients. Late effects higher than grade 2 were observed in 3.0 % of cases. Functional and cosmetic outcomes were optimal in 68.4 % of patients. Interstitial brachytherapy for carcinoma of the eyelid can achieve local control, cosmetic and functional results comparable to those of surgery. (orig.) [German] Das Karzinom des Augenlids stellt aufgrund der funktionellen und kosmetischen Beeintraechtigungen dieser anatomischen Region eine therapeutische Herausforderung dar. Ziele der Therapie sind sowohl die Tumorkontrolle als auch ein gutes funktionelles und kosmetisches Ergebnis. Lokale Kontrolle, Toxizitaet sowie funktionelle und kosmetische Ergebnisse bei Patienten mit Karzinom des Augenlids, die mit interstitieller Brachytherapie behandelt wurden, sollten analysiert werden. Sechzig Patienten mit Karzinom des Augenlids wurden mit interstitieller Brachytherapie mit Iridium-192-Draehten

  4. High brachytherapy doses can counteract hypoxia in cervical cancer—a modelling study

    Science.gov (United States)

    Lindblom, Emely; Dasu, Alexandru; Beskow, Catharina; Toma-Dasu, Iuliana

    2017-01-01

    Tumour hypoxia is a well-known adverse factor for the outcome of radiotherapy. For cervical tumours in particular, several studies indicate large variability in tumour oxygenation. However, clinical evidence shows that the management of cervical cancer including brachytherapy leads to high rate of success. It was the purpose of this study to investigate whether the success of brachytherapy for cervical cancer, seemingly regardless of oxygenation status, could be explained by the characteristics of the brachytherapy dose distributions. To this end, a previously used in silico model of tumour oxygenation and radiation response was further developed to simulate the treatment of cervical cancer employing a combination of external beam radiotherapy and intracavitary brachytherapy. Using a clinically-derived brachytherapy dose distribution and assuming a homogeneous dose delivered by external radiotherapy, cell survival was assessed on voxel level by taking into account the variation of sensitivity with oxygenation as well as the effects of repair, repopulation and reoxygenation during treatment. Various scenarios were considered for the conformity of the brachytherapy dose distribution to the hypoxic region in the target. By using the clinically-prescribed brachytherapy dose distribution and varying the total dose delivered with external beam radiotherapy in 25 fractions, the resulting values of the dose for 50% tumour control, D 50, were in agreement with clinically-observed values for high cure rates if fast reoxygenation was assumed. The D 50 was furthermore similar for the different degrees of conformity of the brachytherapy dose distribution to the tumour, regardless of whether the hypoxic fraction was 10%, 25%, or 40%. To achieve 50% control with external RT only, a total dose of more than 70 Gy in 25 fractions would be required for all cases considered. It can thus be concluded that the high doses delivered in brachytherapy can counteract the increased

  5. [Permanent implant prostate cancer brachytherapy: 2013 state-of-the art].

    Science.gov (United States)

    Cosset, J-M; Hannoun-Lévi, J-M; Peiffert, D; Delannes, M; Pommier, P; Pierrat, N; Nickers, P; Thomas, L; Chauveinc, L

    2013-04-01

    With an experience of more than 25 years for the pioneers (and more than 14 years in France), permanent implant brachytherapy using iodine 125 seeds (essentially) is now recognized as a valuable alternative therapy for localized low-risk prostate cancer patients. The possible extension of the indications of exclusive brachytherapy towards selected patients in the intermediate-risk group has now been confirmed by several studies. Moreover, for the other patients in the intermediate-risk group and for the patients in the high-risk group, brachytherapy, as an addition to external radiotherapy, could represent one of the best ways to escalate the dose. Different permanent implant brachytherapy techniques have been proposed; preplanning or real-time procedure, loose or stranded seeds (or both), manual or automatic injection of the seeds. The main point here is the ability to perfectly master the procedure and to comply with the dosimetric constraints, which have been recently redefined by the international societies, such as the GEC-ESTRO group. Mid- and long-term results, which are now available in the literature, indicate relapse-free survival rates of about 90% at 5-10 years, the best results being obtained with satisfactory dosimetric data. Comparative data have shown that the incontinence and impotence rates after brachytherapy seemed to be significantly inferior to what is currently observed after surgery. However, a risk of about 3 to 5% of urinary retention is usually reported after brachytherapy, as well as an irritative urinary syndrome, which may significantly alter the quality of life of the patients, and last several months. In spite of those drawbacks, with excellent long-term results, low rates of incontinence and impotence, and emerging new indications (focal brachytherapy, salvage brachytherapy after localized failure of an external irradiation), permanent implant prostate brachytherapy can be expected to be proposed to an increasing number of patients

  6. Study of dose calculation on breast brachytherapy using prism TPS

    Energy Technology Data Exchange (ETDEWEB)

    Fendriani, Yoza; Haryanto, Freddy [Nuclear Physics and Biophysics Research Division, FMIPA Institut Teknologi Bandung, Physics Buildings, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2015-09-30

    PRISM is one of non-commercial Treatment Planning System (TPS) and is developed at the University of Washington. In Indonesia, many cancer hospitals use expensive commercial TPS. This study aims to investigate Prism TPS which been applied to the dose distribution of brachytherapy by taking into account the effect of source position and inhomogeneities. The results will be applicable for clinical Treatment Planning System. Dose calculation has been implemented for water phantom and CT scan images of breast cancer using point source and line source. This study used point source and line source and divided into two cases. On the first case, Ir-192 seed source is located at the center of treatment volume. On the second case, the source position is gradually changed. The dose calculation of every case performed on a homogeneous and inhomogeneous phantom with dimension 20 × 20 × 20 cm{sup 3}. The inhomogeneous phantom has inhomogeneities volume 2 × 2 × 2 cm{sup 3}. The results of dose calculations using PRISM TPS were compared to literature data. From the calculation of PRISM TPS, dose rates show good agreement with Plato TPS and other study as published by Ramdhani. No deviations greater than ±4% for all case. Dose calculation in inhomogeneous and homogenous cases show similar result. This results indicate that Prism TPS is good in dose calculation of brachytherapy but not sensitive for inhomogeneities. Thus, the dose calculation parameters developed in this study were found to be applicable for clinical treatment planning of brachytherapy.

  7. Dose volume analysis in brachytherapy and stereotactic radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Tozer-Loft, S.M

    2000-12-01

    A brief introduction to three branches of radiotherapy is given: interstitial brachytherapy, external beam megavoltage radiotherapy, and stereotactic radiosurgery. The current interest in issues around conformity, uniformity and optimisation is explained in the light of technical developments in these fields. A novel method of displaying dose-volume information, which mathematically suppresses the inverse-square law, as first suggested by L.L. Anderson for use in brachytherapy is explained in detail, and some improvements proposed. These 'natural' histograms are extended to show the effects of real point sources which do not exactly follow the inverse-square law, and to demonstrate the in-target dose-volume distribution, previously unpublished. The histograms are used as a way of mathematically analysing the properties of theoretical mono-energetic radionuclides, and for demonstrating the dosimetric properties of a potential new brachytherapy source (Ytterbium-169). A new modification of the Anderson formalism is then described for producing Anderson Inverse-Square Shifted (AISS) histograms for the Gamma Knife, which are shown to be useful for demonstrating the quality of stereotactic radiosurgery dose distributions. A study is performed analysing the results of Gamma Knife treatments on 44 patients suffering from a benign brain tumour (acoustic neuroma). Follow-up data is used to estimate the volume shrinkage or growth of each tumour, and this measure of outcome is compared with a range of figures of merit which express different aspects of the quality of each dose distributions. The results are analysed in an attempt to answer the question: What are the important features of the dose distribution (conformality, uniformity, etc) which show a definite relationship with the outcome of the treatment? Initial results show positively that, when Gamma Knife radiosurgery is used to treat acoustic neuroma, some measures of conformality seem to have a surprising

  8. [Endobronchial brachytherapy: state of the art in 2013].

    Science.gov (United States)

    Derhem, N; Sabila, H; Mornex, F

    2013-04-01

    Endobronchial brachytherapy is an invasive technique, which allows localizing radioactive sources at the tumour contact. Therefore, high doses are administered to tumour while healthy tissues can be spared. Initially dedicated to a palliative setting, improvements helped reaching 60 to 88% symptoms alleviation and 30 to 100% of endoscopic macroscopic response. New diagnostic techniques and early diagnosis extended the indications to a curative intent: endoluminal primitive tumour, post radiation endobronchial recurrence, inoperable patients. CT-based dosimetry is a keypoint to optimize treatment quality and to minimize potential side effects, making this treatment a safe and efficient technique for specific indications.

  9. Survival following interstitial brachytherapy for recurrent malignant glioma.

    Science.gov (United States)

    Kitchen, N D; Hughes, S W; Taub, N A; Sofat, A; Beaney, R P; Thomas, D G

    1994-01-01

    The treatment of recurrent malignant glioma is difficult and at present largely disappointing. Furthermore the results of any treatment modality need to be interpreted with knowledge regarding patient selection and timing of treatment. The results of interstitial brachytherapy using iodine-125 in 23 patients are presented. There were no operative complications. Median survival time from tumour recurrence and implantation was 36 and 25 weeks respectively. Karnofsky Performance Status (KPS) was significantly associated with survival, though patient age, original tumour histology, prior chemotherapy, and time to recurrence were not. Treatment does confer modest survival benefit as compared to controls, but our results are not as impressive as others. Reasons for this finding are discussed.

  10. Prosper: image and robot-guided prostate brachytherapy

    CERN Document Server

    Baumann, Michael; Daanen, Vincent; Descotes, Jean-Luc; Giraud, Jean-Yves; Hungr, Nikolai; Leroy, Antoine; Long, Jean-Alexandre; Martin, Sébastien; Troccaz, Jocelyne

    2011-01-01

    Brachytherapy for localized prostate cancer consists in destroying cancer by introducing iodine radioactive seeds into the gland through hollow needles. The planning of the position of the seeds and their introduction into the prostate is based on intra-operative ultrasound (US) imaging. We propose to optimize the global quality of the procedure by: i) using 3D US; ii) enhancing US data with MRI registration; iii) using a specially designed needle-insertion robot, connected to the imaging data. The imaging methods have been successfully tested on patient data while the robot accuracy has been evaluated on a realistic deformable phantom.

  11. Salvage robot-assisted radical prostatectomy after brachytherapy: our experience

    Directory of Open Access Journals (Sweden)

    A. V. Govorov

    2014-01-01

    Full Text Available In case of recurrence of prostate cancer after radiation therapy patient may be offered salvage radical prostatectomy (both open and laparoscopic/robotic, hormone therapy, and a number of alternative techniques such as salvage cryoablation, HIFU-therapy and brachytherapy. Results of monitoring of patients for 10 years after salvage treatment of prostate cancer are known only after salvage prostatectomy. Technically radical prostatectomy after radiation therapy is associated with a large number of complications if compared with primary radical prostatectomy. The most frequent complications after salvage prostatectomy include incontinence, stricture formation of urethrovesical anastomosis, rectal injury, acute urinary retention and infectious complications.

  12. Growth delay effect of combined interstitial hyperthermia and brachytherapy in a rat solid tumor model.

    Science.gov (United States)

    Papadopoulos, D; Kimler, B F; Estes, N C; Durham, F J

    1989-01-01

    The rat mammary AC33 solid tumor model was used to investigate the efficacy of interstitial hyperthermia and/or brachytherapy. Subcutaneous flank tumors were heated with an interstitial microwave (915 MHz) antenna to a temperature of 43 +/- 0.5 degrees C for 45 min for two treatments, three days apart, and/or implanted with Ir-192 seeds for three days (-25 Gy tumor dose). Following treatments, tumors were measured 2 to 3 times per week. Hyperthermia alone produced a modest delay in tumor volume regrowth, while brachytherapy was substantially more effective. The combination produced a improvement in tumor regrowth delay compared to brachytherapy alone.

  13. High dose brachytherapy in pediatric oncology; Braquiterapia com alta taxa de dose em oncologia pediatrica

    Energy Technology Data Exchange (ETDEWEB)

    Ferrigno, Robson; Codjaian, Osanna Esther; Novaes, Paulo Eduardo R.S.; Trippe, Nivaldo [Fundacao Antonio Prudente, Sao Paulo, SP (Brazil). Hospital A.C. Camargo. Dept. de Radioterapia

    1995-05-01

    Brachytherapy is a kind of radiotherapy that has been used in the multidisciplinary approach of some pediatric tumors, such as soft tissue sarcomas of the extremities, head and neck and urogenital tract. Recent technological advances in this area lead to development of computerized high dose rate remote afterloading brachytherapy. This type of treatment has some advantages compared to low dose rate brachytherapy traditionally used. This article describes not only the characteristics and advantages of this kind of treatment, but also the preliminary results of the first seven children treated with high dose rate at the Hospital A.C.Camargo. (author) 10 refs., 8 figs.

  14. A case of percutaneous high dose rate brachytherapy for superior pulmonary sulcus tumor

    Energy Technology Data Exchange (ETDEWEB)

    Asakura, Tamaki; Imamura, Masahiro; Murata, Takashi [Kansai Medical Univ., Moriguchi, Osaka (Japan)] [and others

    1996-07-01

    A 64-year-old man with advanced superior pulmonary sulcus tumor suffered severe unrelieved pain even after chemotherapy, external irradiation and hyperthermia. So we planned to introduce a percutaneous high dose rate brachytherapy using the microselectron HDR {sup 192}Ir. With the estimation using the Pain Score, satisfying pain relief was attainable with a combination of the percutaneous high dose rate brachytherapy and conventional treatment. So the percutaneous high dose rate brachytherapy had the possibility to contribute to the alleviation of the pain. (author)

  15. Study of factors influencing dose distribution of brachytherapy in cervical cancer

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective To study the factors which influence the dose distribution of brachytherapy in cervical cancer.Methods Ninety-five patients with cervical cancer Ⅱ-Ⅲb received fundamental radiation therapy including brachytherapy in our department from Aug.2004 to Nov.2005.The deviation of isodose curve of brachytherapy was based on A-B reference system,and the deviation of dose was defined by measuring in a practical standard body model.Results The factors influencing isodose offset significantly were parametrial...

  16. LOW-DOSE RATE BRACHYTHERAPY FOR PROSTATE CANCER: DIFFERENT INDICATIONS – DIFFERENT RESULTS

    Directory of Open Access Journals (Sweden)

    V. A. Biryukov

    2014-07-01

    Full Text Available In Russia, there is presently a growing interest in low-dose intratissue radiotherapy (brachytherapy for locally advanced prostate cancer (PC. Since its inception, current brachytherapy has undergone a number of significant changes in terms of improved visualization and better treatment planning and monitoring, which is sure to have affected the higher quality of their performance and better long-term results. The main purpose of the given paper is to generalize the data of foreign investigators who have the greatest experience with brachytherapy for its further use in the treatment of patients with locally advanced PC under the conditions of Russian clinics.

  17. Use of Monte Carlo Methods in brachytherapy; Uso del metodo de Monte Carlo en braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Granero Cabanero, D.

    2015-07-01

    The Monte Carlo method has become a fundamental tool for brachytherapy dosimetry mainly because no difficulties associated with experimental dosimetry. In brachytherapy the main handicap of experimental dosimetry is the high dose gradient near the present sources making small uncertainties in the positioning of the detectors lead to large uncertainties in the dose. This presentation will review mainly the procedure for calculating dose distributions around a fountain using the Monte Carlo method showing the difficulties inherent in these calculations. In addition we will briefly review other applications of the method of Monte Carlo in brachytherapy dosimetry, as its use in advanced calculation algorithms, calculating barriers or obtaining dose applicators around. (Author)

  18. The role of brachytherapy in the definitive management of prostate cancer; Place de la curietherapie dans le traitement du cancer prostatique localise

    Energy Technology Data Exchange (ETDEWEB)

    Crook, J. [British Columbia Cancer Agency, Center for the Southern Interior, 399, Royal Avenue, Kelowna, British Columbia, V1Y 5L33 (Canada)

    2011-06-15

    Over the past two decades, brachytherapy has played an ever expanding role in the definitive radiotherapy of prostate cancer. Brachytherapy surpasses external beam radiotherapy in its ability to deliver intense intra-prostatic dose escalation. Although initially low dose rate permanent seed brachytherapy was favored for favorable risk prostate cancers, and high dose rate temporary brachytherapy for intermediate and advanced disease, both types of brachytherapy now have a place across all the risk groups of localized prostate cancer. This article will review indications and patient selection, planning and technical aspects, toxicity and efficacy for both low and high dose rate prostate brachytherapy. (author)

  19. American Brachytherapy Task Group Report: Adjuvant vaginal brachytherapy for early-stage endometrial cancer: A comprehensive review.

    Science.gov (United States)

    Harkenrider, Matthew M; Block, Alec M; Alektiar, Kaled M; Gaffney, David K; Jones, Ellen; Klopp, Ann; Viswanathan, Akila N; Small, William

    This article aims to review the risk stratification of endometrial cancer, treatment rationale, outcomes, treatment planning, and treatment recommendations of vaginal brachytherapy (VBT) in the postoperative management of endometrial cancer patients. The authors performed a thorough review of the literature and reference pertinent articles pertaining to the aims of this review. Adjuvant VBT for early-stage endometrial cancer patients results in very low rates of vaginal recurrence (0-3.1%) with low rates of late toxicity which are primarily vaginal in nature. Post-Operative Radiation Therapy in Endometrial Cancer 2 (PORTEC-2) supports that VBT results in noninferior rates of vaginal recurrence compared to external beam radiotherapy for the treatment of high-intermediate risk patients. VBT as a boost after external beam radiotherapy, in combination with chemotherapy, and for high-risk histologies have shown excellent results as well though randomized data do not exist supporting VBT boost. There are many different applicators, dose-fractionation schedules, and treatment planning techniques which all result in favorable clinical outcomes and low rates of toxicity. Recommendations have been published by the American Brachytherapy Society and the American Society of Radiation Oncology to help guide practitioners in the use of VBT. Data support that patients and physicians prefer joint decision making regarding the use of VBT, and patients often desire additional treatment for a marginal benefit in risk of recurrence. Discussions regarding adjuvant therapy for endometrial cancer are best performed in a multidisciplinary setting, and patients should be counseled properly regarding the risks and benefits of adjuvant therapy. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  20. Monte Carlo Dosimetry of the 60Co BEBIG High Dose Rate for Brachytherapy.

    Directory of Open Access Journals (Sweden)

    Luciana Tourinho Campos

    Full Text Available The use of high-dose-rate brachytherapy is currently a widespread practice worldwide. The most common isotope source is 192Ir, but 60Co is also becoming available for HDR. One of main advantages of 60Co compared to 192Ir is the economic and practical benefit because of its longer half-live, which is 5.27 years. Recently, Eckert & Ziegler BEBIG, Germany, introduced a new afterloading brachytherapy machine (MultiSource®; it has the option to use either the 60Co or 192Ir HDR source. The source for the Monte Carlo calculations is the new 60Co source (model Co0.A86, which is referred to as the new BEBIG 60Co HDR source and is a modified version of the 60Co source (model GK60M21, which is also from BEBIG.The purpose of this work is to obtain the dosimetry parameters in accordance with the AAPM TG-43U1 formalism with Monte Carlo calculations regarding the BEBIG 60Co high-dose-rate brachytherapy to investigate the required treatment-planning parameters. The geometric design and material details of the source was provided by the manufacturer and was used to define the Monte Carlo geometry. To validate the source geometry, a few dosimetry parameters had to be calculated according to the AAPM TG-43U1 formalism. The dosimetry studies included the calculation of the air kerma strength Sk, collision kerma in water along the transverse axis with an unbounded phantom, dose rate constant and radial dose function. The Monte Carlo code system that was used was EGSnrc with a new cavity code, which is a part of EGS++ that allows calculating the radial dose function around the source. The spectrum to simulate 60Co was composed of two photon energies, 1.17 and 1.33 MeV. Only the gamma part of the spectrum was used; the contribution of the electrons to the dose is negligible because of the full absorption by the stainless-steel wall around the metallic 60Co. The XCOM photon cross-section library was used in subsequent simulations, and the photoelectric effect, pair

  1. Monte Carlo Dosimetry of the 60Co BEBIG High Dose Rate for Brachytherapy

    Science.gov (United States)

    Campos, Luciana Tourinho; de Almeida, Carlos Eduardo Veloso

    2015-01-01

    Introduction The use of high-dose-rate brachytherapy is currently a widespread practice worldwide. The most common isotope source is 192Ir, but 60Co is also becoming available for HDR. One of main advantages of 60Co compared to 192Ir is the economic and practical benefit because of its longer half-live, which is 5.27 years. Recently, Eckert & Ziegler BEBIG, Germany, introduced a new afterloading brachytherapy machine (MultiSource®); it has the option to use either the 60Co or 192Ir HDR source. The source for the Monte Carlo calculations is the new 60Co source (model Co0.A86), which is referred to as the new BEBIG 60Co HDR source and is a modified version of the 60Co source (model GK60M21), which is also from BEBIG. Objective and Methods The purpose of this work is to obtain the dosimetry parameters in accordance with the AAPM TG-43U1 formalism with Monte Carlo calculations regarding the BEBIG 60Co high-dose-rate brachytherapy to investigate the required treatment-planning parameters. The geometric design and material details of the source was provided by the manufacturer and was used to define the Monte Carlo geometry. To validate the source geometry, a few dosimetry parameters had to be calculated according to the AAPM TG-43U1 formalism. The dosimetry studies included the calculation of the air kerma strength Sk, collision kerma in water along the transverse axis with an unbounded phantom, dose rate constant and radial dose function. The Monte Carlo code system that was used was EGSnrc with a new cavity code, which is a part of EGS++ that allows calculating the radial dose function around the source. The spectrum to simulate 60Co was composed of two photon energies, 1.17 and 1.33 MeV. Only the gamma part of the spectrum was used; the contribution of the electrons to the dose is negligible because of the full absorption by the stainless-steel wall around the metallic 60Co. The XCOM photon cross-section library was used in subsequent simulations, and the

  2. Observations on rotating needle insertions using a brachytherapy robot

    Energy Technology Data Exchange (ETDEWEB)

    Meltsner, M A [Department of Medical Physics, University of Wisconsin, Madison, WI 53706 (United States); Ferrier, N J [Department of Mechanical Engineering, University of Wisconsin, Madison, WI 53706 (United States); Thomadsen, B R [Department of Medical Physics, University of Wisconsin, Madison, WI 53706 (United States)

    2007-09-21

    A robot designed for prostate brachytherapy implantations has the potential to greatly improve treatment success. Much of the research in robotic surgery focuses on measuring accuracy. However, there exist many factors that must be optimized before an analysis of needle placement accuracy can be determined. Some of these parameters include choice of the needle type, insertion velocity, usefulness of the rotating needle and rotation speed. These parameters may affect the force at which the needle interacts with the tissue. A reduction in force has been shown to decrease the compression of the prostate and potentially increase the accuracy of seed position. Rotating the needle as it is inserted may reduce frictional forces while increasing accuracy. However, needle rotations are considered to increase tissue damage due to the drilling nature of the insertion. We explore many of the factors involved in optimizing a brachytherapy robot, and the potential effects each parameter may have on the procedure. We also investigate the interaction of rotating needles in gel and suggest the rotate-cannula-only method of conical needle insertion to minimize any tissue damage while still maintaining the benefits of reduced force and increased accuracy.

  3. Intraoperative fluoroscopic dose assessment in prostate brachytherapy patients.

    Science.gov (United States)

    Reed, Daniel R; Wallner, Kent E; Narayanan, Sreeram; Sutlief, Steve G; Ford, Eric C; Cho, Paul S

    2005-09-01

    To evaluate a fluoroscopy-based intraoperative dosimetry system to guide placement of additional sources to underdosed areas, and perform computed tomography (CT) verification. Twenty-six patients with prostate carcinoma treated with either I-125 or Pd-103 brachytherapy at the Puget Sound VA using intraoperative postimplant dosimetry were analyzed. Implants were performed by standard techniques. After completion of the initial planned brachytherapy procedure, the initial fluoroscopic intraoperative dose reconstruction analysis (I-FL) was performed with three fluoroscopic images acquired at 0 (AP), +15, and -15 degrees. Automatic seed identification was performed and the three-dimensional (3D) seed coordinates were computed and imported into VariSeed for dose visualization. Based on a 3D assessment of the isodose patterns additional seeds were implanted, and the final fluoroscopic intraoperative dose reconstruction was performed (FL). A postimplant computed tomography (CT) scan was obtained after the procedure and dosimetric parameters and isodose patterns were analyzed and compared. An average of 4.7 additional seeds were implanted after intraoperative analysis of the dose coverage (I-FL), and a median of 5 seeds. After implantation of additional seeds the mean V100 increased from 89% (I-FL) to 92% (FL) (p sources to supplement inadequately dosed areas within the prostate gland. Additionally, guided implantation of additional source, can significantly improve V100s and D90s, without significantly increasing rectal doses.

  4. Dosimetric study of I-125 seeds used in prostate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Maira R.; Rosa, Luiz A.R. da, E-mail: mairasantos@ird.gov.br, E-mail: lrosa@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Facure, Alessandro, E-mail: facure@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Cardoso, Simone C., E-mail: simone@if.ufrj.br [Laboratorio de Fisica da Radiacao Gama e X, Instituto de Fisica (IF/UFRJ), Universidade Federal do Rio de Janeiro, RJ (Brazil); Pereira, Pedro P. [Dosimetrika, Rio de Janeiro, RJ (Brazil); Instituto Nacional de Cancer, E-mail: ppereira@dosimetrika.com.br [INCA-MS, Rio de Janeiro, RJ (Brazil); Silva, Ademir X. da, E-mail: ademir@con.ufrj.br [PEN/COPPE/UFRJ, Universidade Federal do Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Among the possibilities for treatment of prostate cancer, radiotherapy is one of the most commonly used procedures. One of the radiation therapy modalities is brachytherapy, where radioactive sources are placed near or in contact with the tumor mass. Prostate Brachytherapy with iodine seed permanent implantation has become increasingly widespread because it is less invasive and offers the possibility of lower doses to organs at risk and therefore less side effects to patients. The planning for this type of treatment includes the acquisition of images and the delineation of the contours of organs at risk. Generally, important factors for dose administration as, for example, the actual composition of tissues and geometry particularities of the seeds used in the treatment are disregarded. In order to assess the impact of such approaches on the outcome of prostate permanent implant treatment, experimental results, performed with TLD detectors in a prostate phantom of solid water (RW3), and the formalism of the protocol compiled by the Task Group No.43 of the American Association of Physicists in Medicine, were compared for two different irradiation geometries. The present results indicate a good agreement between them. These dataset offers the possibility to determine correction factors that may be applied in actual treatment planning. (author)

  5. Methodology of quality control for brachytherapy {sup 125}I seeds

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Eduardo S.; Zeituni, Carlos A.; Manzoli, Jose E.; Rostelato, Maria Elisa C.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: esmoura@ipen.br

    2007-07-01

    This paper presents the methodology of quality control of {sup 125}I seeds used for brachytherapy. The {sup 125}I seeds are millimeter titanium capsules widely used in permanent implants of prostate cancer, allowing a high dose within the tumour and a low dose on the surrounding tissues, with very low harm to the other tissues. Besides, with this procedure, the patients have a low impotence rate and a small incidence of urinary incontinence. To meet the medical standards, an efficient quality control is necessary, showing values with the minimum uncertainness possible, concerning the seeds dimensions and their respective activities. The medical needles are used to insert the seeds inside the prostate. The needles used in brachytherapy have an internal diameter of 1.0 mm, so it is necessary {sup 125}I seeds with an external maximum diameter of 0.85 mm. For the seeds and the spacer positioning on the planning sheet, the seeds must have a length between 4.5 and 5.0 mm. The activities must not vary more than 5% in each batch of {sup 125}I seeds. For this methodology, we used two ionization chamber detectors and one caliper. In this paper, the methodology using one control batch with 75 seeds manufactured by GE Health care Ltd is presented. (author)

  6. Review of advanced catheter technologies in radiation oncology brachytherapy procedures

    Directory of Open Access Journals (Sweden)

    Zhou J

    2015-07-01

    Full Text Available Jun Zhou,1,2 Leonid Zamdborg,1 Evelyn Sebastian1 1Department of Radiation Oncology, Beaumont Health System, 2Oakland University William Beaumont School of Medicine, Royal Oak, MI, USA Abstract: The development of new catheter and applicator technologies in recent years has significantly improved treatment accuracy, efficiency, and outcomes in brachytherapy. In this paper, we review these advances, focusing on the performance of catheter imaging and reconstruction techniques in brachytherapy procedures using magnetic resonance images and electromagnetic tracking. The accuracy of catheter reconstruction, imaging artifacts, and other notable properties of plastic and titanium applicators in gynecologic treatments are reviewed. The accuracy, noise performance, and limitations of electromagnetic tracking for catheter reconstruction are discussed. Several newly developed applicators for accelerated partial breast irradiation and gynecologic treatments are also reviewed. New hypofractionated high dose rate treatment schemes in prostate cancer and accelerated partial breast irradiation are presented. Keywords: catheter technologies, catheter reconstruction, electromagnetic tracking, hypofractionated high dose rate treatment, accelerated partial breast irradiation

  7. Iodine-125 orbital brachytherapy with a prosthetic implant in situ

    Energy Technology Data Exchange (ETDEWEB)

    Stannard, Clare [Groote Schuur Hospital and Cape Town Univ. (South Africa). Dept. of Radiation Oncology; Maree, Gert; Munro, Roger [Groote Schuur Hospital and Cape Town Univ. (South Africa). Dept. of Medical Physics; Lecuona, Karin [Groote Schuur Hospital and Cape Town Univ. (South Africa). Dept. of Ophthalmology; Sauerwein, Wolfgang [Universitaetsklinikum Essen (Germany). Strahlenklinik, NCTeam

    2011-05-15

    Purpose: Brachytherapy is one method of irradiating the orbit after enucleation of an eye with a malignant tumor that has a potential to recur. It consists of 6 trains of I-125 seeds placed around the periphery of the orbit, a shorter central train, and a metal disc, loaded with seeds, placed beneath the eyelids. The presence of a prosthetic orbital implant requires omission of the central train and adjustment of the activity of the seeds in the anterior orbit around the prosthesis. Patients and Methods: This is a retrospective review of the technical modifications and outcome of 12 patients treated in this manner: 6 with retinoblastoma, 5 with malignant melanoma, and 1 with an intraocular rhabdomyosarcoma. The median dose was 35.5 Gy in 73 hours for retinoblastoma and 56 Gy in 141 hours for malignant melanoma. Patients with retinoblastoma and rhabdomyosarcoma also received chemotherapy. Results: The tubes can be placed satisfactorily around the prosthesis. The increased activity in the anterior half of the tubes produced comparable dose distributions. There have been no orbital recurrences, no extrusion of the prosthesis, and cosmesis is good. Conclusion: Insertion of a prosthetic implant at the time of enucleation greatly enhances the subsequent cosmetic appearance. This should be encouraged unless there is frank tumor in the orbit. Orbital brachytherapy without the central train continues to give excellent local control. The short treatment time and good cosmesis are added advantages. The patient is spared the expense and inconvenience of removing and replacing the prosthetic implant. (orig.)

  8. Radiation Protection in Brachytherapy. Report of the SEFM Task Group on Brachytherapy; Proteccion radiologica en Braquiterapia. Informe del grupo de trabajo de Braquiterapia de la SEFM

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Calatayud, J.; Corredoira Silva, E.; Crispin Contreras, V.; Eudaldo Puell, T.; Frutos Baraja, J. de; Pino Sorroche, F.; Pujades Claumarchirant, M. C.; Richart Sancho, J.

    2015-07-01

    This document presents the report of the Brachytherapy Task Group of the Spanish Society of Medical Physics. It is dedicated to the radiation protection aspects involved in brachytherapy. The aim of this work is to include the more relevant aspects related to radiation protection issues that appear in clinical practice, and for the current equipment in Spain. Basically this report focuses on the typical contents associated with high dose rate brachytherapy with {sup 1}92Ir and {sup 6}0Co sources, and permanent seed implants with {sup 1}25I, {sup 1}03Pd and {sup 1}31Cs, which are the most current and widespread modalities. Ophthalmic brachytherapy (COMS with {sup 1}25I, {sup 1}06Ru, {sup 9}0Sr) is also included due to its availability in a significant number of spanish hospitals. The purpose of this report is to assist to the medical physicist community in establishing a radiation protection program for brachytherapy procedures, trying to solve some ambiguities in the application of legal requirements and recommendations in clinical practice. (Author)

  9. Gafchromic film dosimetry of a new HDR  192Ir brachytherapy source

    National Research Council Canada - National Science Library

    Ayoobian, Navid; Asl, Akbar Sarabi; Poorbaygi, Hosein; Javanshir, Mohammad Reza

    2016-01-01

    High‐dose‐rate (HDR) brachytherapy is a popular modality for treating cancers of the prostate, cervix, endometrium, breast, skin, bronchus, esophagus, and head and neck as well as soft‐tissue sarcomas...

  10. Penile cancer brachytherapy HDR mould technique used at the Holycross Cancer Center

    OpenAIRE

    Matys, Robert; Kubicka-Mendak, Iwona; Łyczek, Jarosław; Pawłowski, Piotr; Stawiarska, Iwona; Miedzinska, Joanna; Banatkiewicz, Paweł; Łaskawska-Wiatr, Aldona; Wittych, Justyna

    2011-01-01

    The aim of this pictorial essay is to present the mould based HDR brachytherapy technique used at the Holycross Cancer Center for penile cancer patients. We use images to describe this method step by step.

  11. Penile cancer brachytherapy HDR mould technique used at the Holycross Cancer Center.

    Science.gov (United States)

    Matys, Robert; Kubicka-Mendak, Iwona; Lyczek, Jarosław; Pawłowski, Piotr; Stawiarska, Iwona; Miedzinska, Joanna; Banatkiewicz, Paweł; Laskawska-Wiatr, Aldona; Wittych, Justyna

    2011-12-01

    The aim of this pictorial essay is to present the mould based HDR brachytherapy technique used at the Holycross Cancer Center for penile cancer patients. We use images to describe this method step by step.

  12. Study of factors influencing dose distribution of brachytherapy in cervical cancer

    Institute of Scientific and Technical Information of China (English)

    Liu Zi; Gao Ying; Luo Wei; Wang Guoqing; Wang Ruihua; Zheng Wei; Liu Rui

    2008-01-01

    Objective To study the factors which influence the dose distribution of brachytherapy in cervical cancer. Methods Ninety-five patients with cervical cancer Ⅱ - Ⅲ b received fundamental radiation therapy including brachytherapy in our department from Aug. 2004 to Nov. 2005. The deviation of isodose curve of brachytherapy was based on A-B reference system, and the deviation of dose was defined by measuring in a practical standard body model. Results The factors influencing isodose offset significantly were parametrial infiltrating degree, and anatomy factor of cervical cancer and operating skill. The degree of isodose offset could not be lowered with the increased frequency of brachytherapy. Conclusion Making simulation in cervical brachythecapy is necessary not only for the identification of the deviation of isodose curve but also for adjusting the dose distribution and revising the plan of radiotherapy.

  13. Brachytherapy, A viable option of globe salvage in treatment of large ciliary body melanocytoma

    Directory of Open Access Journals (Sweden)

    Mahesh P Shanmugam

    2014-01-01

    Full Text Available We report a case of large histopathologically proven melanocytoma of the ciliary body in a 15-year-old male, presented with rapid extraocular growth following incisional biopsy with scleral patch graft. We chose brachytherapy with Ruthenium 106 plaque over enucleation as the later was refused by the parents. The initial apical height of the tumor was 14.2 mm on ultrasonography. Two weeks after brachytherapy, the mass regressed to a size of 8.1 mm and 1 year later to 6.7 mm. This is the first case report showing the response of brachytherapy to ciliary body melanocytoma, which results in ocular and visual acuity salvation with considerable decreased in size of the tumor. The authors conclude that brachytherapy is an option in the management of non-resectable melanocytoma of the ciliary body.

  14. Dosimetry parameters calculation of two commercial iodine brachytherapy sources using SMARTEPANTS with EPDL97 library

    Directory of Open Access Journals (Sweden)

    Navid Ayoobian

    2012-01-01

    Conclusion: The good agreement between the results of this study and previous reports and high computational speed suggest that SMARTEPANTS could be extended to a real-time treatment planning system for 125 I brachytherapy treatments.

  15. Preparation of (103)Pd brachytherapy seeds by electroless plating of (103)Pd onto carbon bars.

    Science.gov (United States)

    Li, Zhong-Yong; Gao, Hui-Bo; Deng, Xue-Song; Zhou, Leng; Zhang, Wen-Hui; Han, Lian-Ge; Jin, Xiao-Hai; Cui, Hai-Ping

    2015-09-01

    A method for preparing (103)Pd brachytherapy seeds is reported. The key of the method was to deposit (103)Pd onto carbon bars by electroless plating so as to prepare source cores. After each carbon bar with (103)Pd was sealed in a titanium capsule, the (103)Pd seeds were fabricated. This paper provides valuable experiences and data for the preparation of (103)Pd brachytherapy seeds.

  16. 6th Annual Conference of Indian Brachytherapy Society 2016 (IBSCON 2016) Proceedings

    OpenAIRE

    Srinivasan, Venkatesan; Kuppusamy, Thayalan; Bhalavat, Rajendra L.; ,; Prahlad H Yathiraj; Kumar, Uday P.; Sharan, Krishna; Singh, Anshul; Reddy, Anusha; Fernandes, Donald; Vidyasagar, M.S.; Kumar, Rishabh; Kala, Prachi; Mandal, Sanjeet; Vibhay, Pareek

    2016-01-01

    Purpose To report the incidence, severity, and time of onset of late toxicities in patients of endometrial adenocarcinoma (EA) treated with external beam radiotherapy (EBRT) + brachytherapy (BT), or vaginal brachytherapy (VBT) alone. Material and methods Archives of a single institution from 2008-2015 were studied. The indications for EBRT and VBT were based on standard recommendations. EBRT was planned to 50 Gy/25 fractions/5 weeks/3DCRT with 4-field ‘box’ technique on a dual energy linear a...

  17. Highly efficient method for production of radioactive silver seed cores for brachytherapy.

    Science.gov (United States)

    Cardoso, Roberta Mansini; de Souza, Carla Daruich; Rostelato, Maria Elisa Chuery Martins; Araki, Koiti

    2017-02-01

    A simple and highly efficient (shorter reaction time and almost no rework) method for production of iodine based radioactive silver seed cores for brachytherapy is described. The method allows almost quantitative deposition of iodine-131 on dozens of silver substrates at once, with even distribution of activity per core and insignificant amounts of liquid and solid radioactive wastes, allowing the fabrication of cheaper radioactive iodine seeds for brachytherapy.

  18. HDR Brachytherapy Dose Distribution is Influenced by the Metal Material of the Applicator

    OpenAIRE

    Chin-Hui Wu; Yi-Jen Liao; An-Cheng Shiau; Hsin-Yu Lin; Yen-Wan Hsueh Liu; Shih-Ming Hsu

    2015-01-01

    Applicators containing metal have been widely used in recent years when applying brachytherapy to patients with cervical cancer. However, the high dose rate (HDR) treatment-planning system (TPS) that is currently used in brachytherapy still assumes that the treatment environment constitutes a homogeneous water medium and does not include a dose correction for the metal material of the applicator. The primary purpose of this study was to evaluate the HDR 192Ir dose distribution in cervical can...

  19. Effect of brachytherapy technique and patient characteristics on cervical cancer implant dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Anker, Christopher J., E-mail: chris.anker@hci.utah.edu [Department of Radiation Oncology, Huntsman Cancer Hospital, University of Utah, Salt Lake City, UT (United States); O' Donnell, Kristen [Department of Radiation Oncology, The University of Arizona, Tucson, AZ (United States); Boucher, Kenneth M. [Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT (United States); Gaffney, David K. [Department of Radiation Oncology, Huntsman Cancer Hospital, University of Utah, Salt Lake City, UT (United States)

    2013-01-01

    Our purpose was to evaluate the relationship between brachytherapy technique and patient characteristics on dose to organs-at-risk (OARs) in patients undergoing high dose rate (HDR) brachytherapy for cervical cancer. From 1998 to 2008, 31 patients with cervical cancer with full dosimetric data were identified who received definitive external-beam radiation and HDR brachytherapy with tandem and ovoid applicators. Doses were recorded at point A, the International Commission on Radiation Units and Measurements (ICRU)-38 rectal point, the ICRU-38 bladder point, the vaginal surface, and the pelvic sidewall. Generalized estimating equations were used to determine the significance of changes in OAR to point A dose ratios with differences in brachytherapy technique or patient characteristics. Patients underwent a median of 5 brachytherapy procedures (range, 3 to 5), with a total of 179 procedures for 31 patients. For all brachytherapy treatments, the average ratios between the doses for the rectal, bladder, vaginal surface, and pelvic sidewall reference points to those at point A were 0.49, 0.59, 1.15, and 0.17, respectively. In general, decreased OAR dose was associated with a lower stage, younger age, increased ovoid size, increased tandem length, and earlier implant number. Increased tandem curvature significantly increased bladder dose and decreased rectal dose. Intravenous anesthesia usage was not correlated with improved dosimetry. This study allowed identification of patient and procedure characteristics influencing OAR dosing. Although the advent of 3-dimensional (3D) image-guided brachytherapy will bring new advances in treatment optimization, the actual technique involved at the time of the brachytherapy implant procedure will remain important.

  20. WE-E-BRD-01: HDR Brachytherapy I: Overview of Clinical Application and QA

    Energy Technology Data Exchange (ETDEWEB)

    Libby, B [University of Virginia, Charlottesville, VA (United States); Showalter, T

    2014-06-15

    With the increased usage of high dose rate (HDR) brachytherapy and the introduction of dedicated image guided brachytherapy suites, it is necessary to review the processes and procedures associated with safely delivering these treatments in the expedited time scales that dedicated treatment suites afford. The speakers will present the clinical aspects of switching from LDR to HDR treatments, including guidelines for patient selection, and the clinical outcomes comparing LDR to HDR. The speakers will also discuss the HDR treatment process itself, because the shortened clinical timeline involved with a streamlined scan/plan/treat workflow can introduce other issues. Safety and QA aspects involved with the streamlined process, including increased personnel required for parallel tasks, and possible interfering tasks causing delays in patient treatments will also be discussed. Learning Objectives: To understand the clinical aspects of HDR Brachytherapy, including common clinical indications, patient selection, and the evolving evidence in support of this therapeutic modality To review the current prominent clinical trials for HDR brachytherapy To interpret the established guidelines for HDR brachytherapy quality assurance for implementation into practical clinical settings. To introduce the basic requirements for image guided brachytherapy.

  1. Brachytherapy in childhood rhabdomyosarcoma treatment; Braquiterapia no tratamento do rabdomiossarcoma da infancia

    Energy Technology Data Exchange (ETDEWEB)

    Novaes, Paulo Eduardo Ribeiro dos Santos

    1995-07-01

    A retrospective study of 21 children with rhabdomyosarcoma treated by brachytherapy to the primary site of the tumor at the Radiotherapy Department of the A.C.Camargo Hospital between january/1980 to june/1993 was undertaken. The main objectives were to comprove the utility of brachytherapy in childhood rhabdomyosarcoma, to evaluate the local control and survival, in association with chemotherapy, to analyze the late effects of the treatment and to determinate the preferential technique to each clinical situation. All patients received brachytherapy to the tumor site. The radioactive isotopes employed were Gold{sup 198}, Cesium{sup 137} and Iridium{sup 192}. The brachytherapy techniques depended on the tumor site, period of treatment, availability of the radioactive material and stage of the disease. Patients treated exclusively by brachytherapy received 40 Gy to 60 Gy. When brachytherapy was associated with external radiotherapy the dose ranged from 20 Gy to 40 Gy. Local control was achieved in 18 of 20 patients (90%). The global survival and local control survival rates were 61.9% (13/21 patients) and 72,2% (13/18 patients) respectively. (author)

  2. Prospective evaluation of patient satisfaction after the use of brachytherapy specific educational materials for cervical cancer.

    Science.gov (United States)

    Rash, Dominique; Hess, Clayton; Lentz, Susan; Tait, Lauren; Michaud, Anthony; Mayadev, Jyoti

    2016-01-01

    Cervical cancer patients are faced with an enormous amount of medical information in a complex oncology field with sophisticated treatments including brachytherapy. We investigated the use of enhanced vs. standard brachytherapy-specific educational materials on patient-reported satisfaction during the informed consent process for intracavitary high-dose-rate brachytherapy. A single-institution, prospective, randomized trial was performed to study patient-reported satisfaction with novel educational materials for high-dose-rate brachytherapy in women undergoing definitive radiation for cervical cancer. Fourteen women receiving informed consent with a customized educational booklet were randomized between no further intervention and take-home educational materials. The weighted average for 10 of 11 survey questions was higher in the intervention arm but ranged between 4 (agree) and 5 (strongly agree) for all questions in both arms. The mean weighted patient satisfaction scores ± standard deviations in the control arm and the intervention arms were 54.3 ± 6.4 and 57.5 ± 2.7, respectively (p = 0.26). Knowledge acquisition is presumed to be part of the coping process for women facing increased stress during a cancer diagnosis. A brachytherapy-specific, visual, patient-educational booklet and take-home materials used to supplement the informed consent process for high-dose-rate brachytherapy resulted in high levels of patient-reported satisfaction among women treated with cervical cancer. Published by Elsevier Inc.

  3. Helmet mold-based surface brachytherapy for homogeneous scalp treatment: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Liebmann, A.; Pohlmann, S.; Heinicke, F.; Hildebrandt, G. [Univ. Hospital Leipzig AoeR (Germany). Dept. of Radiotherapy and Radiooncology

    2007-04-15

    Background/Case Report: External-beam radiotherapy of complex-shaped areas is sometimes difficult to realize. In a patient with chronic lymphatic leukemia (CLL) infiltrates of the skin of the whole scalp, conventional external-beam radiotherapy with electrons or photons was not able to treat the target sufficiently. Thus, the authors developed a brachytherapy moulage technique using a customized helmet (polyethylene) with flexible interstitial plastic applicators and irradiated the target very homogeneously with a microselectron {sup 192}Ir HDR (high-dose-rate) source (2.0 Gy daily fractionated; 36.0 Gy total dose related to the reference points in 3 mm focus depth). Technical difficulties, CT-supported three-dimensional conformal treatment planning, and verification with TLD probe measurements are described. The treatment was well tolerated and resulted in complete local remission of the CLL infiltrates within a follow-up of 30 months. Conclusion: The presented treatment of lymphoma infiltrates at the scalp by HDR moulage techniques is exceptional but safe and practicable to achieve local tumor control.

  4. Synthesis and characterization of hydroxyapatite porous matrixes for application as radiation sources in brachytherapy; Sintese e caracterizacao de matrizes porosas de hidroxiapatita para aplicacao como fontes radioativas em braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, Kassio Andre; Lameiras, Fernando Soares; Silva, Viviane Viana [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mail: kassiolacerda@yahoo.com.br

    2006-04-15

    Porous ceramic materials based on calcium phosphate compounds (CPC) have been studied aiming at different biomedical applications such as implants, drug delivery systems and radioactive sources for brachytherapy. Two kinds of hydroxyapatite (HAp) powders and their ceramic bodies were characterized by a combination of different techniques (X-rays diffraction and fluorescence, infrared spectrophotometry, BET method, thermal analysis, and scanning electron microscopy) to evaluate their physico-chemical and microstructural characteristics in terms of chemical composition, segregated phases, microstructure, porosity, and chemical and thermal stability. The results revealed that these systems presented potential for use as porous biodegradable radioactive sources able to be loaded with a wide range of radionuclides for cancer treatment by the brachytherapy technique. (author)

  5. Dosimetry revisited for the HDR {sup 192}Ir brachytherapy source model mHDR-v2

    Energy Technology Data Exchange (ETDEWEB)

    Granero, Domingo; Vijande, Javier; Ballester, Facundo; Rivard, Mark J. [Radiation Physics Department, ERESA, Hospital General Universitario, E-46014 Valencia (Spain); Department of Atomic, Molecular, and Nuclear Physics, University of Valencia, E-46100 Burjassot (Spain) and IFIC, CSIC-University of Valencia, E-46100 Burjassot (Spain); Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States)

    2011-01-15

    Purpose: Recently, the manufacturer of the HDR {sup 192}Ir mHDR-v2 brachytherapy source reported small design changes (referred to herein as mHDR-v2r) that are within the manufacturing tolerances but may alter the existing dosimetric data for this source. This study aimed to (1) check whether these changes affect the existing dosimetric data published for this source; (2) obtain new dosimetric data in close proximity to the source, including the contributions from {sup 192}Ir electrons and considering the absence of electronic equilibrium; and (3) obtain scatter dose components for collapsed cone treatment planning system implementation. Methods: Three different Monte Carlo (MC) radiation transport codes were used: MCNP5, PENELOPE2008, and GEANT4. The source was centrally positioned in a 40 cm radius water phantom. Absorbed dose and collision kerma were obtained using 0.1 mm (0.5 mm) thick voxels to provide high-resolution dosimetry near (far from) the source. Dose-rate distributions obtained with the three MC codes were compared. Results: Simulations of mHDR-v2 and mHDR-v2r designs performed with three radiation transport codes showed agreement typically within 0.2% for r{>=}0.25 cm. Dosimetric contributions from source electrons were significant for r<0.25 cm. The dose-rate constant and radial dose function were similar to those from previous MC studies of the mHDR-v2 design. The 2D anisotropy function also coincided with that of the mHDR-v2 design for r{>=}0.25 cm. Detailed results of dose distributions and scatter components are presented for the modified source design. Conclusions: Comparison of these results to prior MC studies showed agreement typically within 0.5% for r{>=}0.25 cm. If dosimetric data for r<0.25 cm are not needed, dosimetric results from the prior MC studies will be adequate.

  6. Tissue modeling schemes in low energy breast brachytherapy.

    Science.gov (United States)

    Afsharpour, Hossein; Landry, Guillaume; Reniers, Brigitte; Pignol, Jean-Philippe; Beaulieu, Luc; Verhaegen, Frank

    2011-11-21

    Breast tissue is heterogeneous and is mainly composed of glandular (G) and adipose (A) tissues. The proportion of G versus A varies considerably among the population. The absorbed dose distributions in accelerated partial breast irradiation therapy with low energy photon brachytherapy sources are very sensitive to tissue heterogeneities. Current clinical algorithms use the recommendations of the AAPM TG43 report which approximates the human tissues by unit density water. The aim of this study is to investigate various breast tissue modeling schemes for low energy brachytherapy. A special case of breast permanent seed implant is considered here. Six modeling schemes are considered. Uniform and non-uniform water breast (UWB and NUWB) consider the density but neglect the effect of the composition of tissues. The uniform and the non-uniform G/A breast (UGAB and NUGAB) as well the age-dependent breast (ADB) models consider the effect of the composition. The segmented breast tissue (SBT) method uses a density threshold to distinguish between G and A tissues. The PTV D(90) metric is used for the analysis and is based on the dose to water (D(90(w,m))). D(90(m,m)) is also reported for comparison to D(90(w,m)). The two-month post-implant D(90(w,m)) averaged over 38 patients is smaller in NUWB than in UWB by about 4.6% on average (ranging from 5% to 13%). Large average differences of G/A breast models with TG43 (17% and 26% in UGAB and NUGAB, respectively) show that the effect of the chemical composition dominates the effect of the density on dose distributions. D(90(w,m)) is 12% larger in SBT than in TG43 when averaged. These differences can be as low as 4% or as high as 20% when the individual patients are considered. The high sensitivity of dosimetry on the modeling scheme argues in favor of an agreement on a standard tissue modeling approach to be used in low energy breast brachytherapy. SBT appears to generate the most geometrically reliable breast tissue models in this

  7. Dosimetric equivalence of nonstandard HDR brachytherapy catheter patterns

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, J. A. M.; Hsu, I-C.; Pouliot, J. [University of California, San Francisco, California 94115 (United States)

    2009-01-15

    Purpose: To determine whether alternative high dose rate prostate brachytherapy catheter patterns can result in similar or improved dose distributions while providing better access and reducing trauma. Materials and Methods: Standard prostate cancer high dose rate brachytherapy uses a regular grid of parallel needle positions to guide the catheter insertion. This geometry does not easily allow the physician to avoid piercing the critical structures near the penile bulb nor does it provide position flexibility in the case of pubic arch interference. This study used CT datasets with 3 mm slice spacing from ten previously treated patients and digitized new catheters following three hypothetical catheter patterns: conical, bi-conical, and fireworks. The conical patterns were used to accommodate a robotic delivery using a single entry point. The bi-conical and fireworks patterns were specifically designed to avoid the critical structures near the penile bulb. For each catheter distribution, a plan was optimized with the inverse planning algorithm, IPSA, and compared with the plan used for treatment. Irrelevant of catheter geometry, a plan must fulfill the RTOG-0321 dose criteria for target dose coverage (V{sub 100}{sup Prostate}>90%) and organ-at-risk dose sparing (V{sub 75}{sup Bladder}<1 cc, V{sub 75}{sup Rectum}<1 cc, V{sub 125}{sup Urethra}<<1 cc). Results: The three nonstandard catheter patterns used 16 nonparallel, straight divergent catheters, with entry points in the perineum. Thirty plans from ten patients with prostate sizes ranging from 26 to 89 cc were optimized. All nonstandard patterns fulfilled the RTOG criteria when the clinical plan did. In some cases, the dose distribution was improved by better sparing the organs-at-risk. Conclusion: Alternative catheter patterns can provide the physician with additional ways to treat patients previously considered unsuited for brachytherapy treatment (pubic arch interference) and facilitate robotic guidance of

  8. Highly conformal CT based surface mould brachytherapy for non-melanoma skin cancers of earlobe and nose

    Science.gov (United States)

    Kozłowski, Sławomir; Pietraszek, Andrzej; Pietrzykowska-Kuncman, Malwina; Danielska, Justyna; Sobotkowski, Janusz; Łuniewska-Bury, Jolanta; Fijuth, Jacek

    2016-01-01

    Purpose Brachytherapy (BT), due to rapid dose fall off and minor set-up errors, should be superior to external beam radiotherapy (EBRT) for treatment of lesions in difficult locations like nose and earlobe. Evidences in this field are scarce. We describe computed tomography (CT) based surface mould BT for non-melanoma skin cancers (NMSC), and compare its conformity, dose coverage, and tissue sparing ability to EBRT. Material and methods We describe procedure of preparation of surface mould applicator and dosimetry parameters of BT plans, which were implemented in 10 individuals with NMSC of nose and earlobe. We evaluated dose coverage by minimal dose to 90% of planning target volume (PTV) (D90), volumes of PTV receiving 90-150% of prescribed dose (PD) (VPTV90-150), conformal index for 90 and 100% of PD (COIN90, COIN100), dose homogeneity index (DHI), dose nonuniformity ratio (DNR), exposure of organs. Prospectively, we created CT-based photons and electrons plans. We compared conformity (COIN90, COIN100), dose coverage of PTV (D90, VPTV90, VPTV100), volumes of body receiving 10-90% of PD (V10-V90) of EBRT and BT plans. Results We obtained mean BT-DHI = 0.76, BT-DNR = 0.23, EBRT-DHI = 1.26. We observed no significant differences in VPTV90 and D90 between BT and EBRT. Mean BT-VPTV100 (89.4%) was higher than EBRT-VPTV100 (71.2%). Both COIN90 (BT-COIN90 = 0.46 vs. EBRT-COIN90 = 0.21) and COIN100 (BT-COIN100 = 0.52 vs. EBRT-COIN100 = 0.26) were superior for BT plans. We observed more exposure of normal tissues for small doses in BT plans (V10, V20), for high doses in EBRT plans (V70, V90). Conclusions Computed tmography-based surface mould brachytherapy for superficial lesions on irregular surfaces is a highly conformal method with good homogeneity. Brachytherapy is superior to EBRT in those locations in terms of conformity and normal tissue sparing ability in high doses. PMID:27504128

  9. Radiological response of ceramic and polymeric devices for breast brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Batista Nogueira, Luciana, E-mail: lucibn19@yahoo.com.br [Departamento de Propedeutica Complementar, Faculdade de Medicina, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Pampulha 31270901, BH/MG (Brazil); Passos Ribeiro de Campos, Tarcisio, E-mail: campos@nuclear.ufmg.br [Departamento de Engenharia Nuclear, Programa de Pos Graduacao em Ciencias e Tecnicas Nucleares, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Pampulha 31270901, BH/MG (Brazil)

    2012-04-15

    In the present study, the radiological visibility of ceramic and polymeric devices implanted in breast phantom was investigated for future applications in brachytherapy. The main goal was to determine the radiological viability of ceramic and polymeric devices in vitro by performing simple radiological diagnostic methods such as conventional X-ray analysis and mammography due to its easy access to the population. The radiological response of ceramic and polymeric devices implanted in breast phantom was determined using conventional X-ray, mammography and CT analysis. - Highlights: Black-Right-Pointing-Pointer Radiological visibility of ceramic and polymeric devices implanted in breast phantom. Black-Right-Pointing-Pointer The barium incorporation in the seed improves the radiological contrast. Black-Right-Pointing-Pointer Radiological monitoring shows the position, orientation and degradation of devices. Black-Right-Pointing-Pointer Simple radiological methods such as X-ray and mammography were used for radiological monitoring.

  10. Refining prostate seed brachytherapy: Comparing high-, intermediate-, and low-activity seeds for I-125 permanent seed prostate brachytherapy.

    Science.gov (United States)

    Delouya, Guila; Bahary, Pascal; Carrier, Jean-François; Larouche, Renée-Xavière; Hervieux, Yannick; Béliveau-Nadeau, Dominic; Donath, David; Taussky, Daniel

    2015-01-01

    To analyze the difference in prostate coverage and dose to the rectum in men with prostate carcinoma treated with permanent seed brachytherapy with different seed activities. Forty-nine patients treated with iodine-125 permanent seed prostate brachytherapy with low-activity seeds of 0.30-0.37 mCi were identified. For each of these patients, 2 patients with similar prostate volume (±2 cc) were paired: one treated with intermediate seed activity (0.44-0.46 mCi) and one with high seed activity (0.60-0.66 mCi). The doses to prostate and rectum were compared using CT on Day 30. A total of 147 patients divided into the three seed activity groups were analyzed. Mean prostate volume was 35.7 cc (standard deviation [SD], 11.70). Compared with low-activity seeds, implants with high-activity seeds consisted of an average of 22 seeds and 4.7 needles less. The dose to the prostate (prostate volume receiving 100% of the prescribed dose [V100], prostate volume receiving 150% of the prescribed dose, and minimal dose covering 90% of the prostate volume expressed in Gy) was not higher on Day 30 (p = 0.58-0.97). The mean volume (in cubic centimeters) of rectal wall receiving 100% of the prescribed dose (V100) increased with activity: low activity, 0.34 cc (SD, 0.49), intermediate activity, 0.47 cc (SD, 0.48), and high activity, 0.72 cc (SD, 0.79) (p = 0.009). There was a trend (p = 0.073) toward a higher frequency of clinically unfavorable rectal dosimetry (V100 > 1.3 cc) in patients with high-activity seeds (16.7%) compared with low-activity (6.3%) or intermediate-activity (4.2%) seeds. High-activity seeds do not result in a higher dose to the prostate but in a higher dose to the rectum. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  11. A Monte Carlo investigation of lung brachytherapy treatment planning

    Science.gov (United States)

    Sutherland, J. G. H.; Furutani, K. M.; Thomson, R. M.

    2013-07-01

    Iodine-125 (125I) and Caesium-131 (131Cs) brachytherapy have been used in conjunction with sublobar resection to reduce the local recurrence of stage I non-small cell lung cancer compared with resection alone. Treatment planning for this procedure is typically performed using only a seed activity nomogram or look-up table to determine seed strand spacing for the implanted mesh. Since the post-implant seed geometry is difficult to predict, the nomogram is calculated using the TG-43 formalism for seeds in a planar geometry. In this work, the EGSnrc user-code BrachyDose is used to recalculate nomograms using a variety of tissue models for 125I and 131Cs seeds. Calculated prescription doses are compared to those calculated using TG-43. Additionally, patient CT and contour data are used to generate virtual implants to study the effects that post-implant deformation and patient-specific tissue heterogeneity have on perturbing nomogram-derived dose distributions. Differences of up to 25% in calculated prescription dose are found between TG-43 and Monte Carlo calculations with the TG-43 formalism underestimating prescription doses in general. Differences between the TG-43 formalism and Monte Carlo calculated prescription doses are greater for 125I than for 131Cs seeds. Dose distributions are found to change significantly based on implant deformation and tissues surrounding implants for patient-specific virtual implants. Results suggest that accounting for seed grid deformation and the effects of non-water media, at least approximately, are likely required to reliably predict dose distributions in lung brachytherapy patients.

  12. Development of prostate voxel models for brachytherapy treatment

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Adriano M.; Reis, Lucas P.; Grynberg, Suely E., E-mail: amsantos@cdtn.b [Center for Development of Nuclear Technology (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The tools developed recently in the areas of computer graphics and animation movies to computer games allow the creation of new voxel anthropomorphic phantoms with better resolution and thus, more anatomical details. These phantoms can be used in nuclear applications, especially in radiation protection for estimating doses in cases of occupational or accidental radioactive incidents, and in medical and biological applications. For dose estimates, the phantoms are coupled to a Monte Carlo code, which will be responsible for the transport of radiation in this environment. This study aimed to develop a computational tool to estimate the isodose curves in the prostate after brachytherapy seed implants. For this, we have created a model called FANTPROST in the shape of a 48 mm side cube, with a standard prostate inserted in the center of this cube with different distributions of brachytherapy seeds in this volume. The prostate, according to this model, was obtained from the phantom voxels MASH2 developed by Numerical Dosimetry Group, Department of Nuclear Energy - Federal University of Pernambuco. The modeling of the seeds, added to FANTPROST, was done through the use of geometric information of Iodine-125 Amersham 6711 commercial seed. The simulations were performed by the code MCNP5 for spatial distributions containing different amounts of seeds within the FANTPROST. The obtained curves allowed an estimation of the behavior of the maximum dose that decreases with distance, showing that this tool can be used for a more accurate analysis of the effects produced by the presence of such seeds in the prostate and its vicinity. (author)

  13. ACR appropriateness criteria: Permanent source brachytherapy for prostate cancer.

    Science.gov (United States)

    Davis, Brian J; Taira, Al V; Nguyen, Paul L; Assimos, Dean G; D'Amico, Anthony V; Gottschalk, Alexander R; Gustafson, Gary S; Keole, Sameer R; Liauw, Stanley L; Lloyd, Shane; McLaughlin, Patrick W; Movsas, Benjamin; Prestidge, Bradley R; Showalter, Timothy N; Vapiwala, Neha

    To provide updated American College of Radiology (ACR) appropriateness criteria for transrectal ultrasound-guided transperineal interstitial permanent source brachytherapy. The ACR appropriateness criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. Permanent prostate brachytherapy (PPB) is a treatment option for appropriately selected patients with localized prostate cancer with low to very high risk disease. PPB monotherapy remains an appropriate and effective curative treatment for low-risk prostate cancer patients demonstrating excellent long-term cancer control and acceptable morbidity. PPB monotherapy can be considered for select intermediate-risk patients with multiparametric MRI useful in evaluation of such patients. High-risk patients treated with PPB should receive supplemental external beam radiotherapy (EBRT) along with androgen deprivation. Similarly, patients with involved pelvic lymph nodes may also be considered for such combined treatment but reported long-term outcomes are limited. Computed tomography-based postimplant dosimetry completed within 60 days of PPB is essential for quality assurance. PPB may be considered for treatment of local recurrence after EBRT but is associated with an increased risk of toxicity. Updated appropriateness criteria for patient evaluation, selection, treatment, and postimplant dosimetry are given. These criteria are intended to be advisory only with the final responsibility for patient care residing with the treating

  14. Iodine-125 interstitial brachytherapy for experimental liver cancer

    Institute of Scientific and Technical Information of China (English)

    ZHOU Fei-guo; YAN Jian-jun; HUANG Liang; LIU Cai-feng; ZHANG Xiang-hua; ZHOU Wei-ping; YAN Yi-qun

    2007-01-01

    Objective:To study the effect of iodine-125 interstitial brachytherapy on liver cancer.Methods:Animal model of human liver cancer was established by injecting SMMC-7721 cells cultivated in vitro subcutaneously into the flank of BALB/c nude mice.Nude mice with tumor of 5 mm in diameter were randomly divided into 2 groups(n=10).One iodine-125 seed of apparent activity 0.8 mCi was implanted into the center of tumor in treatment group,whereas an inactive seed was implanted in control group.The other 20 nude mice with tumor reaching 10 mm in diameter were also treated as above.The size of tumor was determined weekly after implantation,and pathological examination and blood routine were taken on the 28th day.Results:Tumor growth was obviously inhibited in treatment group of tumor of 5 mm in diameter,and there was statistically significant difference in tumor volume between treatment and control groups(P<0.01).Around iodine-125 seed,apparent necrosis of tumor was shown in treatment group,accompanied by karyopyknosis and reduced plasma in residual tumor cells microscopically.Tumor growth was not inhibited in either treatment or control group of tumor of 10 mm in diameter.There was no obvious adverse effect except for decreased white blood cells in treatment groups.Conclusion:There is certain effect of iodine-125 interstitial brachytherapy on liver cancer,which is associated with the size of tumor.

  15. The calorimetric measurement of low energy brachytherapy sources

    Science.gov (United States)

    Aus, Robert John

    Historically, the dose rate to tissue from 125I and 103Pd sources was based on a source's apparent activity in free space. The American Association of Physicists in Medicine Task Group 43 (TG43) established a protocol that clarified this formalism for the dose rate determination that was universally accepted in the Medical Physics community. The TG43 protocol is based on air kerma strength and a different set of conversion factors for determining the dose rate. However, there are still many uncertainties associated with this methodology. These uncertainties are predominantly the result of the unknown effects of variations in the source encapsulation and internal source structure on the dose distribution surrounding a source. Currently, there is no method of nondestructively determining the contained radioactivity of brachytherapy sources. Without the knowledge of the contained activity, the effects of source construction variations cannot be evaluated accurately. The goal of this work was to develop a calorimeter that measures the total power generated by a source. This information could then be used to nondestructively determine the contained radioactivity activity of a source. The power generated by three different, well characterized source designs of 125I brachytherapy seeds was measured with the calorimeter. A theoretical model of the calorimeter was also developed to demonstrate that the calorimeter operated as expected. The measured and theoretical temperature results for the three different source models were consistent within the uncertainty of the measurements. The consistency between the calorimetric measurements and the theoretical expected results demonstrates proof of principle of the calorimeter. The information determined from the model can also be useful for future calorimetric research by identifying required calorimeter design features, potential design improvements and potential difficulties.

  16. The role of vaginal cuff brachytherapy in endometrial cancer.

    Science.gov (United States)

    Harkenrider, Matthew M; Block, Alec M; Siddiqui, Zaid A; Small, William

    2015-02-01

    The purpose of this article is to review the data, rationale, and recommendations of vaginal brachytherapy (VBT) in the post-operative treatment of endometrial cancer patients. The authors performed a thorough review of the medical literature regarding the use of adjuvant VBT in the treatment of endometrial cancer. Relevant data are presented in this review. Additionally, personal and institutional practices from the authors are incorporated where relevant. VBT for the adjuvant treatment of early stage endometrial cancer patients results in a low rate of recurrence (0-3.1%) with very low rates of toxicity. PORTEC-2 supports the use of adjuvant VBT versus external beam radiotherapy specifically for high-intermediate risk endometrial cancer patients. VBT has low rates of acute and chronic gastrointestinal and genitourinary toxicity and very low rates of second primary malignancy. The primary toxicity of VBT is vaginal atrophy and stenosis with controversy regarding the use of vaginal dilators for prevention. Data support that patients prefer to be involved in the decision making process for their adjuvant therapy, and patients have a lower minimal desired benefit of adjuvant VBT than do physicians. Guidelines exist from the American Brachytherapy Society and American Society of Radiation Oncology with support from the Society for Gynecologic Oncologists regarding the use of adjuvant VBT. VBT decreases the risk of recurrence with minimal toxicity in the adjuvant treatment of endometrial cancer. Adjuvant therapy should be discussed in a multi-disciplinary setting with detailed counseling of the risks and benefits with the patient so that she ultimately makes an informed decision regarding her adjuvant therapy. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Perioperative brachytherapy for pretreated chest wall recurrence of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, A.; Naszaly, A.; Patyanik, M. [Municipal Center of Oncoradiology, Budapest (Hungary)

    2002-11-01

    Purpose: To demonstrate the technical aspects of high-dose-rate afterloading (HDR-AL) brachytherapy for isolated local chest wall recurrence of breast cancer pretreated with mastectomy and axillary node dissection plus postoperative radiotherapy. Case Report: A 63-year-old female patient with left ductal breast cancer, pT2pN1biMO, was reoperated for an isolated local chest wall recurrence 13 years after primary treatment (mastectomy, axillary dissection, and 50 Gy postoperative irradiation). Radical surgery would have involved extreme multilation. Reoperative surgical margins of 3 mm width were involved, and four parallel afterloading catheters were placed intraoperatively in this histologically positive margin site. Perioperative HDR-AL (Ir-192 stepping source, 370 GBq activity, dose rate: reference air kerma rate at 1 m 40.84 mGy/h kg) was performed. Dose per fraction: 6 Gy to the reference line, two fractions per week, total dose 30 Gy. Follow-up after secondary treatment: 5 years. Results: Firm local control and 5-year disease-free survival were obtained with perioperative HDR-AL therapy; staging procedures (clinical exam, MRI, abdominal ultrasound, and bone scan) showed no evidence of disease. The development of radiodermatitis did not exceed grade 2 level and healed spontaneously within 6 weeks. Conclusions: Isolated local chest all relapse can be effectively controlled by wide surgical excision and perioperative reirradiation with HDR-AL. This technique may represent a treatment alternative to ultraradical surgery, with equal healing probability and a better quality of life. Small-volume irradiation of the postoperative scar can be performed with HDR-AL brachytherapy, and long-term local control can be achieved with a total dose of 30 Gy. (orig.)

  18. Monte Carlo study of the impact of a magnetic field on the dose distribution in MRI-guided HDR brachytherapy using Ir-192

    Science.gov (United States)

    Beld, E.; Seevinck, P. R.; Lagendijk, J. J. W.; Viergever, M. A.; Moerland, M. A.

    2016-09-01

    In the process of developing a robotic MRI-guided high-dose-rate (HDR) prostate brachytherapy treatment, the influence of the MRI scanner’s magnetic field on the dose distribution needs to be investigated. A magnetic field causes a deflection of electrons in the plane perpendicular to the magnetic field, and it leads to less lateral scattering along the direction parallel with the magnetic field. Monte Carlo simulations were carried out to determine the influence of the magnetic field on the electron behavior and on the total dose distribution around an Ir-192 source. Furthermore, the influence of air pockets being present near the source was studied. The Monte Carlo package Geant4 was utilized for the simulations. The simulated geometries consisted of a simplified point source inside a water phantom. Magnetic field strengths of 0 T, 1.5 T, 3 T, and 7 T were considered. The simulation results demonstrated that the dose distribution was nearly unaffected by the magnetic field for all investigated magnetic field strengths. Evidence was found that, from a dose perspective, the HDR prostate brachytherapy treatment using Ir-192 can be performed safely inside the MRI scanner. No need was found to account for the magnetic field during treatment planning. Nevertheless, the presence of air pockets in close vicinity to the source, particularly along the direction parallel with the magnetic field, appeared to be an important point for consideration.

  19. Brachytherapy of endometrial cancers; Curietherapie des cancers de l'endometre

    Energy Technology Data Exchange (ETDEWEB)

    Peiffert, D.; Hoffstetter, S.; Charra-Brunaud, C. [Centre Alexis-Vautrin, Unite de Curietherapie, 54 - Vandoeuvre-les-Nancy (France)

    2003-04-01

    Endometrial adenocarcinomas rank third as tumoral sites en France. The tumors are confined to the uterus in 80% of the cases. Brachytherapy has a large place in the therapeutic strategy. The gold standard treatment remains extra-fascial hysterectomy with bilateral annexiectomy and bilateral internal iliac lymph node dissection. However, after surgery alone, the rate of locoregional relapses reaches 4-20%, which is reduced to 0-5% after postoperative brachytherapy of the vaginal cuff. This postoperative brachytherapy is delivered as outpatients treatment, by 3 or 4 fractions, at high dose rate. The utero-vaginal preoperative brachytherapy remains well adapted to the tumors which involve the uterine cervix. Patients presenting a localized tumor but not operable for general reasons (< 10%) can be treated with success by exclusive irradiation, which associates a pelvic irradiation followed by an utero-vaginal brachytherapy. A high local control of about 80-90% is obtained, a little lower than surgery, with a higher risk of late complications. Last but not least, local relapses in the vaginal cuff, or in the perimeatic area, can be treated by interstitial salvage brachytherapy, associated if possible with external beam irradiation. The local control is reached in half of the patients, but metastatic dissemination is frequent. We conclude that brachytherapy has a major role in the treatment of endometrial adenocarcinomas, in combination with surgery, or with external beam irradiation for not operable patients or in case of local relapses. It should use new technologies now available including computerized after-loaders and 3D dose calculation. (authors)

  20. A fibre optic scintillator dosemeter for absorbed dose measurements of low-energy X-ray-emitting brachytherapy sources.

    Science.gov (United States)

    Sliski, Alan; Soares, Christopher; Mitch, Michael G

    2006-01-01

    A newly developed dosemeter using a 0.5 mm diameter x 0.5 mm thick cylindrical plastic scintillator coupled to the end of a fibre optic cable is capable of measuring the absorbed dose rate in water around low-activity, low-energy X-ray emitters typically used in prostate brachytherapy. Recent tests of this dosemeter showed that it is possible to measure the dose rate as a function of distance in water from 2 to 30 mm of a (103)Pd source of air-kerma strength 3.4 U (1 U = 1 microGy m(2) h(-1)), or 97 MBq (2.6 mCi) apparent activity, with good signal-to-noise ratio. The signal-to-noise ratio is only dependent on the integration time and background subtraction. The detector volume is enclosed in optically opaque, nearly water-equivalent materials so that there is no polar response other than that due to the shape of the scintillator volume chosen, in this case cylindrical. The absorbed dose rate very close to commercial brachytherapy sources can be mapped in an automated water phantom, providing a 3-D dose distribution with sub-millimeter spatial resolution. The sensitive volume of the detector is 0.5 mm from the end of the optically opaque waterproof housing, enabling measurements at very close distances to sources. The sensitive detector electronics allow the measurement of very low dose rates, as exist at centimeter distances from these sources. The detector is also applicable to mapping dose distributions from more complex source geometries such as eye applicators for treating macular degeneration.

  1. Automation system for quality control in manufacture of iodine-125 sealed sources used in brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Somessari, Samir L.; Feher, Anselmo; Sprenger, Francisco E.; Rostellato, Maria E.C.M.; Moura, Joao A.; Costa, Osvaldo L.; Calvo, Wilson A.P., E-mail: somessar@ipen.b, E-mail: afeher@ipen.b, E-mail: sprenger@ipen.b, E-mail: elisaros@ipen.b, E-mail: olcosta@ipen.b, E-mail: wapcalvo@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The objective of this work is to develop an automation system for Quality Control in the production of Iodine-125 sealed sources, after undergoing the process of laser beam welding. These sources, also known as Iodine-125 seeds are used, successfully, in the treatment of cancer by brachytherapy, with low-dose rates. Each small seed is composed of a welded titanium capsule with 0.8 mm diameter and 4.5 mm in length, containing Iodine-125 adsorbed on an internal silver wire. The seeds are implanted in the human prostate to irradiate the tumor and treat the cancerous cells. The technology to automate the quality control system in the manufacture of Iodine-125 seeds consists in developing and associate mechanical parts, electronic components and pneumatic circuits to control machines and processes. The automation technology for Iodine-125 seed production developed in this work employs programmable logic controller, step motors, drivers of control, electrical-electronic interfaces, photoelectric sensors, interfaces of communication and software development. Industrial automation plays an important role in the production of Iodine-125 seeds, with higher productivity and high standard of quality, facilitating the implementation and operation of processes with good manufacturing practices. Nowadays, the Radiation Technology Center at IPEN-CNEN/SP imports and distributes 36,000 Iodine-125 seeds per year for clinics and hospitals in the whole country. However, the Brazilian potential market is of 8,000 Iodine-125 seeds per month. Therefore, the local production of these radioactive seeds has become a priority for the Institute, aiming to reduce the price and increase the supply to the population in Brazil. (author)

  2. Size Effects of Gold and Iron Nanoparticles on Radiation Dose Enhancement in Brachytherapy and Teletherapy: A Monte Carlo Study

    Directory of Open Access Journals (Sweden)

    Ahad Ollah Ezzati

    2014-08-01

    Full Text Available Introduction In this study, we aimed to calculate dose enhancement factor (DEF for gold (Au and iron (Fe nanoparticles (NPs in brachytherapy and teletherapy, using Monte Carlo (MC method. Materials and Methods In this study, a new algorithm was introduced to calculate dose enhancement by AuNPs and FeNPs for Iridium-192 (Ir-192 brachytherapy and Cobalt-60 (Co-60 teletherapy sources, using the MC method. In this algorithm, the semi-random distribution of NPs was used instead of the regular distribution. Diameters were assumed to be 15, 30, and 100 nm in brachytherapy and 15 and 30 nm in teletherapy. Monte Carlo MCNP4C code was used for simulations, and NP density values were 0.107 mg/ml and 0.112 mg/ml in brachytherapy and teletherapy, respectively. Results AuNPs significantly enhanced the radiation dose in brachytherapy (approximately 60%, and 100 nm diameter NPs showed the most uniform dose distribution. AuNPs had an insignificant effect on teletherapy radiation field, with a dose enhancement ratio of 3% (about the calculation uncertainty or less. In addition, FeNPs had an insignificant effect on both brachytherapy and teletherapy radiation fields. FeNPs dose enhancement was 3% in brachytherapy and 6% (about the calculation uncertainty or less in teletherapy. Conclusion It can be concluded that AuNPs can significantly increase the absorbed dose in brachytherapy; however, FeNPs do not have a noticeable effect on the absorbed dose

  3. High-dose-rate interstitial brachytherapy for the treatment of penile carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Petera, J.; Odrazka, K.; Zouhar, M.; Bedrosova, J.; Dolezel, M. [Dept. of Oncology and Radiotherapy, Charles Univ. Medical School and Teaching Hospital, Hradec Kralove (Czech Republic)

    2004-02-01

    Background: interstitial low-dose-rate (LDR) brachytherapy allows conservative treatment of T1-T2 penile carcinoma. High-dose-rate (HDR) is often considered to be dangerous for interstitial implants because of a higher risk of complications, but numerous reports suggest that results may be comparable to LDR. Nevertheless, there are no data in the literature available regarding HDR interstitial brachytherapy for carcinoma of the penis. Case report: a 64-year-old man with T1 NO MO epidermoid carcinoma of the glans is reported. Interstitial HDR brachytherapy was performed using the stainless hollow needle technique and a breast template for fixation and good geometry. The dose delivered was 18 x 3 Gy twice daily. Results: after 232 days from brachytherapy, the patient was without any evidence of the tumor, experienced no serious radiation-induced complications, and had a fully functional organ. Conclusion: HDR interstitial brachytherapy is feasible in selected case of penis carcinoma, when careful planning and small single fractions are used. (orig.)

  4. Tolerance of the carotid-sheath contents to brachytherapy: an experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Werber, J.L.; Sood, B.; Alfieri, A.; McCormick, S.A.; Vikram, B. (Department of Otolaryngology--Head and Neck Surgery, New York Medical College, Beth Israel (USA))

    1991-06-01

    Tumor invasion of the carotid artery is a potential indication for brachytherapy, which delivers a high dose of irradiation to residual tumor while limiting the dose to adjacent healthy tissues. The tolerance of carotid-sheath contents to varying doses of brachytherapy, however, has not been clearly established. In order to evaluate brachytherapy effects on carotid-sheath contents, after-loading catheters were implanted bilaterally in 3 groups of 6 rabbits each (18 rabbits). Iridium 192 brachytherapy doses of either 5000 cGy (rad), 9000 cGy, or 13,000 cGy were delivered unilaterally, with the contralateral neck serving as a nonirradiated control in each animal. There were no carotid ruptures and wound healing was normal. Two animals from each group were killed at 6, 20, and 48 weeks. Even at the highest dose (13,000 cGy), nerve conduction studies performed on the vagus nerve prior to sacrifice revealed no increased latency, histologic changes were minimal, and carotid arteries were patent. These observations suggest that the carotid-sheath contents in healthy rabbits could tolerate high doses (up to 13,000 cGy) of low-dose-rate interstitial brachytherapy without complications.

  5. Dosimetric characterization of the M-15 high-dose-rate Iridium-192 brachytherapy source using the AAPM and ESTRO formalism.

    Science.gov (United States)

    Ho Than, Minh-Tri; Munro Iii, John J; Medich, David C

    2015-05-08

    The Source Production & Equipment Co. (SPEC) model M-15 is a new Iridium-192 brachytherapy source model intended for use as a temporary high-dose-rate (HDR) brachytherapy source for the Nucletron microSelectron Classic afterloading system. The purpose of this study is to characterize this HDR source for clinical application by obtaining a complete set of Monte Carlo calculated dosimetric parameters for the M-15, as recommended by AAPM and ESTRO, for isotopes with average energies greater than 50 keV. This was accomplished by using the MCNP6 Monte Carlo code to simulate the resulting source dosimetry at various points within a pseudoinfinite water phantom. These dosimetric values next were converted into the AAPM and ESTRO dosimetry parameters and the respective statistical uncertainty in each parameter also calculated and presented. The M-15 source was modeled in an MCNP6 Monte Carlo environment using the physical source specifications provided by the manufacturer. Iridium-192 photons were uniformly generated inside the iridium core of the model M-15 with photon and secondary electron transport replicated using photoatomic cross-sectional tables supplied with MCNP6. Simulations were performed for both water and air/vacuum computer models with a total of 4 × 109 sources photon history for each simulation and the in-air photon spectrum filtered to remove low-energy photons belowδ = 10 keV. Dosimetric data, including D·(r,θ), gL(r), F(r,θ), φan(r), and φ-an, and their statistical uncertainty were calculated from the output of an MCNP model consisting of an M-15 source placed at the center of a spherical water phantom of 100 cm diameter. The air kerma strength in free space, SK, and dose rate constant, Λ, also was computed from a MCNP model with M-15 Iridium-192 source, was centered at the origin of an evacuated phantom in which a critical volume containing air at STP was added 100 cm from the source center. The reference dose rate, D·(r0,θ0) ≡ D· (1cm

  6. Braquiterapia guiada por imagen Image-guided brachytherapy

    Directory of Open Access Journals (Sweden)

    E. Villafranca

    2009-01-01

    Full Text Available La braquiterapia consiste en la administración de radiación en contacto íntimo con el tumor, con una baja exposición de los tejidos sanos circundantes. Empezó a utilizarse a comienzos del siglo XX y desde entonces ha ido desarrollándose: diferentes radioisótopos, sistemas de tratamiento a distancia, programas informáticos que permiten un cálculo individualizado de la dosis. Los cambios en los últimos años dentro de la braquiterapia han afectado a dos aspectos. En primer lugar, la incorporación de las técnicas de imagen como la ecografía, la tomografía computarizada (TC y la resonancia magnética (RM, imprescindibles para el diagnóstico y la estadificación tumoral. Su utilización mientras se realiza el implante ayuda a guiarlo y realizarlo con mayor precisión. En segundo lugar, la utilización de TC, RM y ecografía permiten mejorar la cobertura del tumor o reducir la dosis a los órganos sanos. Se utilizan dentro de sistemas de planificación inversa, que realizan el cálculo de dosis a partir de las recomendaciones de las dosis a administrar al tumor y a los órganos sanos. En estos programas de planificación es posible hacer los cálculos con mucha rapidez, teniendo en cuenta la colocación en cada momento de la fuente. Esta técnica, llamada planificación en tiempo real, empieza a mostrar ventajas en el tratamiento de los cánceres de próstata. La incorporación de las técnicas de imagen y las mejoras en los sistemas de cálculo han hecho que en la actualidad la braquiterapia juegue un papel importante en el tratamiento del cáncer de próstata, cérvix, mama, tumores de cabeza y cuello, bronquio o esófago.Brachytherapy consists in the administration of radiation in intimate contact with the tumour, with a low exposure of neighbouring healthy tissues. Its use began in the early XX century and it has developed since then: different radioisotopes, systems of remote treatment, computer programs making individual dose

  7. Radiation protection after interstitial permanent prostate brachytherapy implants

    Energy Technology Data Exchange (ETDEWEB)

    Pirraco, R.; Pereira, A.; Cavaco, A. [Instituto Portugues de Oncologia Francisco Gentil - Centro R egional de Oncologia do Porto, SA, Porto (Portugal)

    2006-07-01

    Full text of publication follows: In this study we measure patients radiation exposure dose after interstitial {sup 125}I permanent prostate Brachytherapy implants, and correlate it with dose limits for public, total activity implanted, patient preoperative weight(1), distance between prostate walls and anterior skin surface. Methods and Material: We analyse 20 patients who were implanted with {sup 125}I seeds. The instrument used to measure radiation is a calibrated Berthold Umo LB 123 aco-plated to a LB 1236-H10 detector. Three measurements were taken: at the perineal and anterior pelvic zones on contact with the skin and at 1 m from the patient. The maximum value was taken for all measurements. The dose at a distance of one meter is obtained at anterior pelvic zone, perpendicular to the skin, according to the recommendations of A.A.P.M.(1). The distance between prostate walls was determined using post -operative CT images. Results: The doses at the perineal zone have determined an average of 186 {mu}Sv/h (range: 110 340 {mu}Sv/h) and at surface pelvic zone of 41 {mu}Sv/h (range: 15 103 {mu}Sv/h). The dose at a distance of 1 meter has an average value of 0.4 {mu}Sv/h (range: 0.2 1.0 {mu}Sv/h). The average total activity implanted was 25 mCi (range: 17 38 mCi). The distance between prostate walls and skin pelvic surface of the patients has an average value of 8.9 cm (range: 6.6 -11.5 cm). At a distance of 1 meter from the pelvic zone the dose measured is very low and below dose limits imposed by the European Directive EURATOM 2 and the Portuguese law. For general public to reach annual dose limit (EURATOM - 1 mSv/year) when contacting the pelvic zone, we extrapolate that 4 days (range: 1.6 11.1 days) would be needed, assuming a daily contact period of 6 hours. Conclusion: We established a correlation between the distance of prostate walls to the skin perineal surface and the total dose, but we find no correlation between measured doses, total activity implanted

  8. Toxicity associated with bowel or bladder puncture during gynecologic interstitial brachytherapy.

    Science.gov (United States)

    Shah, Anand P; Strauss, Jonathan B; Gielda, Benjamin T; Zusag, Thomas W

    2010-05-01

    Interstitial brachytherapy for gynecologic malignancies is associated with significant toxicity. Some reports have correlated this toxicity with needle puncture of the visceral organs. This study examined our experience with interstitial brachytherapy and investigated the relationship between the visceral puncture and toxicity. The outcomes of 36 patients treated with interstitial brachytherapy for gynecologic malignancies at a single institution between 2002 and 2007 were reviewed. Computed tomography was used to guide needle placement based solely on tumor coverage. No attempts were made to avoid visceral puncture; however, the source dwell times were minimized in these areas. At a median follow-up of 21 months, the crude locoregional control rate was 78%. Bowel puncture was noted in 26 patients and bladder puncture in 19. The mean operating time was 50 min, and 86% of patients were discharged in source loading carries a low risk of morbidity.

  9. Magnetic resonance imaging for planning intracavitary brachytherapy for the treatment of locally advanced cervical cancer.

    Science.gov (United States)

    Oñate Miranda, M; Pinho, D F; Wardak, Z; Albuquerque, K; Pedrosa, I

    2016-01-01

    Cervical cancer is the third most common gynecological cancer. Its treatment depends on tumor staging at the time of diagnosis, and a combination of chemotherapy and radiotherapy is the treatment of choice in locally advanced cervical cancers. The combined use of external beam radiotherapy and brachytherapy increases survival in these patients. Brachytherapy enables a larger dose of radiation to be delivered to the tumor with less toxicity for neighboring tissues with less toxicity for neighboring tissues compared to the use of external beam radiotherapy alone. For years, brachytherapy was planned exclusively using computed tomography (CT). The recent incorporation of magnetic resonance imaging (MRI) provides essential information about the tumor and neighboring structures making possible to better define the target volumes. Nevertheless, MRI has limitations, some of which can be compensated for by fusing CT and MRI. Fusing the images from the two techniques ensures optimal planning by combining the advantages of each technique.

  10. Simulation of dose distribution for iridium-192 brachytherapy source type-H01 using MCNPX

    Energy Technology Data Exchange (ETDEWEB)

    Purwaningsih, Anik [Center for development of nuclear informatics, National Nuclear Energy Agency, PUSPIPTEK, Serpong, Banten 15310 (Indonesia)

    2014-09-30

    Dosimetric data for a brachytherapy source should be known before it used for clinical treatment. Iridium-192 source type H01 was manufactured by PRR-BATAN aimed to brachytherapy is not yet known its dosimetric data. Radial dose function and anisotropic dose distribution are some primary keys in brachytherapy source. Dose distribution for Iridium-192 source type H01 was obtained from the dose calculation formalism recommended in the AAPM TG-43U1 report using MCNPX 2.6.0 Monte Carlo simulation code. To know the effect of cavity on Iridium-192 type H01 caused by manufacturing process, also calculated on Iridium-192 type H01 if without cavity. The result of calculation of radial dose function and anisotropic dose distribution for Iridium-192 source type H01 were compared with another model of Iridium-192 source.

  11. Simulation of dose distribution for iridium-192 brachytherapy source type-H01 using MCNPX

    Science.gov (United States)

    Purwaningsih, Anik

    2014-09-01

    Dosimetric data for a brachytherapy source should be known before it used for clinical treatment. Iridium-192 source type H01 was manufactured by PRR-BATAN aimed to brachytherapy is not yet known its dosimetric data. Radial dose function and anisotropic dose distribution are some primary keys in brachytherapy source. Dose distribution for Iridium-192 source type H01 was obtained from the dose calculation formalism recommended in the AAPM TG-43U1 report using MCNPX 2.6.0 Monte Carlo simulation code. To know the effect of cavity on Iridium-192 type H01 caused by manufacturing process, also calculated on Iridium-192 type H01 if without cavity. The result of calculation of radial dose function and anisotropic dose distribution for Iridium-192 source type H01 were compared with another model of Iridium-192 source.

  12. Update on prostate brachytherapy: long-term outcomes and treatment-related morbidity.

    Science.gov (United States)

    Kao, Johnny; Cesaretti, Jamie A; Stone, Nelson N; Stock, Richard G

    2011-06-01

    Current research in prostate brachytherapy focuses on five key concepts covered in this review. Transrectal ultrasound-guided prostate brachytherapy assisted by intraoperative treatment planning is the most advanced form of image-guided radiation delivery. Prostate brachytherapy alone for low-risk prostate cancer achieves lower prostate-specific antigen (PSA) nadirs than intensity-modulated radiotherapy (IMRT) or protons while maintaining durable biochemical control in about 90% of patients without late failures seen in surgically treated patients. As an organ-conserving treatment option, seed implant results in a lower rate of erectile dysfunction and urinary incontinence than surgery that has been validated in several recent prospective studies. Combined IMRT and seed implant has emerged as a rational and highly effective approach to radiation-dose escalation for intermediate- and high-risk prostate cancer. Preliminary results suggest that seed implantation may play a role in improving outcomes for historically poor-prognosis locally advanced and recurrent prostate cancers.

  13. Prostate brachytherapy seed migration to the heart seen on cardiovascular computed tomographic angiography

    Directory of Open Access Journals (Sweden)

    Shilpa Sachdeva, MD

    2017-03-01

    Full Text Available Brachytherapy consists of placing radioactive sources into or adjacent to tumors, to deliver conformal radiation treatment. The technique is used for treatment of primary malignancies and for salvage in recurrent disease. Permanent prostate brachytherapy seeds are small metal implants containing radioactive sources of I-125, Pd-103, or Cs-131 encased in a titanium shell. They can embolize through the venous system to the lungs or heart and subsequently be detected by cardiovascular computed tomography. Cardiovascular imagers should be aware of the appearance of migrated seeds, as their presence in the chest is generally benign, so that unnecessary worry and testing are avoided. We report a case of a patient who underwent brachytherapy for prostate cancer and developed a therapeutic seeds embolus to the right ventricle.

  14. Water equivalent phantom materials for 192Ir brachytherapy

    Science.gov (United States)

    Schoenfeld, Andreas A.; Harder, Dietrich; Poppe, Björn; Chofor, Ndimofor

    2015-12-01

    Several solid phantom materials have been tested regarding their suitability as water substitutes for dosimetric measurements in brachytherapy with 192Ir as a typical high energy photon emitter. The radial variations of the spectral photon fluence, of the total, primary and scattered photon fluence and of the absorbed dose to water in the transversal plane of the tested cylindrical phantoms surrounding a centric and coaxially arranged Varian GammaMed afterloading 192Ir brachytherapy source were Monte-Carlo simulated in EGSnrc. The degree of water equivalence of a phantom material was evaluated by comparing the radial dose-to-water profile in the phantom material with that in water. The phantom size was varied over a large range since it influences the dose contribution by scattered photons with energies diminished by single and multiple Compton scattering. Phantom axis distances up to 10 cm were considered as clinically relevant. Scattered photons with energies reaching down into the 25 keV region dominate the photon fluence at source distances exceeding 3.5 cm. The tested phantom materials showed significant differences in the degree of water equivalence. In phantoms with radii up to 10 cm, RW1, RW3, Solid Water, HE Solid Water, Virtual Water, Plastic Water DT, and Plastic Water LR phantoms show excellent water equivalence with dose deviations from a water phantom not exceeding 0.8%, while Original Plastic Water (as of 2015), Plastic Water (1995), Blue Water, polyethylene, and polystyrene show deviations up to 2.6%. For larger phantom radii up to 30 cm, the deviations for RW1, RW3, Solid Water, HE Solid Water, Virtual Water, Plastic Water DT, and Plastic Water LR remain below 1.4%, while Original Plastic Water (as of 2015), Plastic Water (1995), Blue Water, polyethylene, and polystyrene produce deviations up to 8.1%. PMMA plays a separate role, with deviations up to 4.3% for radii not exceeding 10 cm, but below 1% for radii up to 30 cm. As suggested by

  15. The Preliminary Prototype of Medium Dose Rate Brachytherapy Equipment

    Directory of Open Access Journals (Sweden)

    A. Satmoko

    2013-08-01

    Full Text Available A preliminary prototype of a brachytherapy equipment has been constructed. The work started by developing conceptual design, followed by basic design and detailed design. In the conceptual design, design requirements are stated. In the basic design, technical specifications for main components are determined. In detailed design, general drawings are discussed. The prototype consists of three main systems: a mechanical system, an instrumentation system, and a safety system. The mechanical system assures the movement mechanism of the isotope source position beginning from the standby position until the applicators. It consists of three main modules: a position handling module, a container module, and a channel distribution module. The position handling module serves to move the isotope source position. As shielding, the second module is to store the source when the equipment is in standby position. The prototype provides 12 output channels. The channel selection is performed by the third module. The instrumentation system controls the movement of source position by handling motor operations. It consists of several modules. A microcontroller module serves as a control center whose task includes both controlling motors and communicating with computer. A motor module serves to handle motors. 10 sensors, including their signal conditionings, are introduced to read the environment conditions of the equipment. LEDs are used to display these conditions. In order to facilitate the operators’ duty, communication via RS232 is provided. The brachytherapy equipment can therefore be operated by using computer. Interface software is developed using C# language. To complete both mechanical and instrumentation systems performance, a safety system is developed to make sure that the safety for operator and patients from receiving excessive radiation. An interlock system is introduced to guard against abnormal conditions. In the worst case, a manual intervention

  16. Evaluation of 101Rh as a brachytherapy source

    Science.gov (United States)

    Ghorbani, Mahdi; Meigooni, Ali Soleimani

    2015-01-01

    Purpose Recently a number of hypothetical sources have been proposed and evaluated for use in brachytherapy. In the present study, a hypothetical 101Rh source with mean photon energy of 121.5 keV and half-life of 3.3 years, has been evaluated as an alternative to the existing high-dose-rate (HDR) sources. Dosimetric characteristics of this source model have been determined following the recommendation of the Task Group 43 (TG-43) of the American Association of the Physicist in Medicine (AAPM), and the results are compared with the published data for 57Co source and Flexisource 192Ir sources with similar geometries. Material and methods MCNPX Monte Carlo code was used for simulation of the 101Rh hypothetical HDR source design. Geometric design of this hypothetical source was considered to be similar to that of Flexisource 192Ir source. Task group No. 43 dosimetric parameters, including air kerma strength per mCi, dose rate constant, radial dose function, and two dimensional (2D) anisotropy functions were calculated for the 101Rh source through simulations. Results Air kerma strength per activity and dose rate constant for the hypothetical 101Rh source were 1.09 ± 0.01 U/mCi and 1.18 ± 0.08 cGy/(h.U), respectively. At distances beyond 1.0 cm in phantom, radial dose function for the hypothetical 101Rh source is higher than that of 192Ir. It has also similar 2D anisotropy functions to the Flexisource 192Ir source. Conclusions 101Rh is proposed as an alternative to the existing HDR sources for use in brachytherapy. This source provides medium energy photons, relatively long half-life, higher dose rate constant and radial dose function, and similar 2D anisotropy function to the Flexisource 192Ir HDR source design. The longer half-life of the source reduces the frequency of the source exchange for the clinical environment. PMID:26034499

  17. [Prostate brachytherapy: oncological and functional results after 400 cases].

    Science.gov (United States)

    Gastaldi, Emilio; Chiono, Luciano; Gallo, Fabrizio; Giberti, Claudio

    2014-01-01

    Brachytherapy (BT) with real-time technique for the treatment of low and medium risk prostate cancer (CaP) has been a well known practice for over 25 years in the USA and for over 
15 years in Italy. However, it is an uncommon procedure, because of problems related to the organization and cooperation among urologists, radiotherapists and physics, to the competition of alternative therapies, to dogmatic and educational beliefs, and to the poor knowledge of this technique.
 Between May1999 and July 2013, 400 patients with low and medium risk CaP underwent I 125 BT using a "real-time" approach. The seeds implantation was performed using a Mick applicator in the first 190 patients and the "QuickLink" technique in the last 210 cases. Oncologic results were reported for the first 250 cases with a mean follow-up of 10 years, while functional outcomes and complications were assessed in 350 patients with a minimum follow-up of 1 year.
 A good quality implantation was assessed in 90% of the patients (D90>145 Gy). A biochemical failure was assessed, based on Phoenix criteria, in 12 patients (4.8%). Out of these patients, 
10 underwent prostate biopsy (the other 2 patients showed a systemic disease). The biopsy showed a CaP in 6/10 patients who underwent retropubic radical prostatectomy (4 patients) and external radiotherapy (2 patients) respectively. The remaining 4/10 patients with negative biopsy were treated with total androgen blockade (3 patients) and watchful waiting (1 patient) respectively. Functional results showed an incidence of postoperative irritative disorders in 70% of the patients during the first six months and a good recovery of erectile function in 78.8% and 68.2% of the patients after one and five years from BT respectively.
 Brachytherapy is a good alternative to radical prostatectomy in the low and medium risk prostatic cancers with excellent oncologic and functional results.

  18. Plaque Brachytherapy for Uveal Melanoma: A Vision Prognostication Model

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Niloufer [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States); Khan, Mohammad K. [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, Georgia (United States); Bena, James [Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio (United States); Macklis, Roger [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States); Singh, Arun D., E-mail: singha@ccf.org [Department of Ophthalmic Oncology, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (United States)

    2012-11-01

    Purpose: To generate a vision prognostication model after plaque brachytherapy for uveal melanoma. Methods and Materials: All patients with primary single ciliary body or choroidal melanoma treated with iodine-125 or ruthenium-106 plaque brachytherapy between January 1, 2005, and June 30, 2010, were included. The primary endpoint was loss of visual acuity. Only patients with initial visual acuity better than or equal to 20/50 were used to evaluate visual acuity worse than 20/50 at the end of the study, and only patients with initial visual acuity better than or equal to 20/200 were used to evaluate visual acuity worse than 20/200 at the end of the study. Factors analyzed were sex, age, cataracts, diabetes, tumor size (basal dimension and apical height), tumor location, and radiation dose to the tumor apex, fovea, and optic disc. Univariate and multivariable Cox proportional hazards were used to determine the influence of baseline patient factors on vision loss. Kaplan-Meier curves (log rank analysis) were used to estimate freedom from vision loss. Results: Of 189 patients, 92% (174) were alive as of February 1, 2011. At presentation, visual acuity was better than or equal to 20/50 and better than or equal to 20/200 in 108 and 173 patients, respectively. Of these patients, 44.4% (48) had post-treatment visual acuity of worse than 20/50 and 25.4% (44) had post-treatment visual acuity worse than 20/200. By multivariable analysis, increased age (hazard ratio [HR] of 1.01 [1.00-1.03], P=.05), increase in tumor height (HR of 1.35 [1.22-1.48], P<.001), and a greater total dose to the fovea (HR of 1.01 [1.00-1.01], P<.001) were predictive of vision loss. This information was used to develop a nomogram predictive of vision loss. Conclusions: By providing a means to predict vision loss at 3 years after treatment, our vision prognostication model can be an important tool for patient selection and treatment counseling.

  19. Occupational exposure of professionals during interstitial permanent prostate brachytherapy implants

    Energy Technology Data Exchange (ETDEWEB)

    Pirraco, R.; Pereira, A.; Viterbo, T.; Cavaco, A. [Instituto Portugues de Oncologia Francisco Gentil, Centro R egional de Oncologia do Porto, SA, Porto (Portugal)

    2006-07-01

    Full text of publication follows: Introduction: In this study we present dose measurements for professionals exposed during interstitial 125 I permanent prostate brachytherapy implants. Methods and Materials: The implant technique used was intra operative real time using strand and loose seeds. The professionals inside the operating room are an oncologist, a radiologist, a physicist, a nurse and an anesthesiologist. The oncologist and the physicist contact directly the loaded needle with radioactive seeds and two types of measurements were taken: total body and extremities (finger) dose. The rest of the team operates at long distances, but measurements were made. To measure total body equivalent dose we use a Berthold Umo LB 123 coupled with a LB 1236-H10 detector, and we recorded dose, time and distance from implant location. Finger dosemeters are thermo -luminescent dosimeter (TLD) rings that were controlled over one month. Results: 50 cases (average number of applications per year) were analysed for extremities measurements and 9 cases for total body measurements (in this case, the results were extrapolated for 50 cases), with an average of 26.1 mCi total activity per implant (in a range of 17.4 - 40.3 mCi). The finger dose was 1.8 mSv for the oncologist and 1.9 mSv for the physicist. The interpolation of total body equivalent dose for the oncologist was 24 mSv, for the radiologist 6 mSv and 9 mSv for the physicist. The rest of the team did not receive anything but background radiation. The annual national limit dose for workers is 20 mSv for total body irradiation, and 500 mSv for extremities. Conclusion: In conclusion we may say that during interstitial permanent prostate brachytherapy implants, total doses received for all groups are not significant when compared to annual limits for Portuguese laws 1. Even so, our main goal is always to get the less possible dose (ALARA principle). References: 1. Decreto Lei n. 180/2002 de 8 de Agosto. (authors)

  20. SU-F-BRA-04: Prostate HDR Brachytherapy with Multichannel Robotic System

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, F Maria; Podder, T [University Hospitals Case Medical Center, Cleveland, OH (United States); Yu, Y [Thomas Jefferson University, Philadelphia, PA (United States)

    2015-06-15

    Purpose: High-dose-rate (HDR) brachytherapy is gradually becoming popular in treating patients with prostate cancers. However, placement of the HDR needles at desired locations into the patient is challenging. Application of robotic system may improve the accuracy of the clinical procedure. This experimental study is to evaluate the feasibility of using a multichannel robotic system for prostate HDR brachytherapy. Methods: In this experimental study, the robotic system employed was a 6-DOF Multichannel Image-guided Robotic Assistant for Brachytherapy (MIRAB), which was designed and fabricated for prostate seed implantation. The MIRAB has the provision of rotating 16 needles while inserting them. Ten prostate HDR brachytherapy needles were simultaneously inserted using MIRAB into a commercially available prostate phantom. After inserting the needles into the prostate phantom at desired locations, 2mm thick CT slices were obtained for dosimetric planning. HDR plan was generated using Oncetra planning system with a total prescription dose of 34Gy in 4 fractions. Plan quality was evaluated considering dose coverage to prostate and planning target volume (PTV), with 3mm margin around prostate, as well as the dose limit to the organs at risk (OARs) following the American Brachytherapy Society (ABS) guidelines. Results: From the CT scan, it is observed that the needles were inserted straight into the desired locations and they were adequately spaced and distributed for a clinically acceptable HDR plan. Coverage to PTV and prostate were about 91% (V100= 91%) and 96% (V100=96%), respectively. Dose to 1cc of urethra, rectum, and bladder were within the ABS specified limits. Conclusion: The MIRAB was able to insert multiple needles simultaneously into the prostate precisely. By controlling the MIRAB to insert all the ten utilized needles into the prostate phantom, we could achieve the robotic HDR brachytherapy successfully. Further study for assessing the system

  1. MO-FG-210-00: US Guided Systems for Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-06-15

    Ultrasound (US) is one of the most widely used imaging modalities in medical practice. Since US imaging offers real-time imaging capability, it has becomes an excellent option to provide image guidance for brachytherapy (IGBT). (1) The physics and the fundamental principles of US imaging are presented, and the typical steps required to commission an US system for IGBT is provided for illustration. (2) Application of US for prostate HDR brachytherapy, including partial prostate treatments using MR-ultrasound co-registration to enable a focused treatment on the disease within the prostate is also presented. Prostate HDR with US image guidance planning can benefit from real time visualization of the needles, and fusion of the ultrasound images with T2 weighted MR allows the focusing of the treatment to the specific areas of disease within the prostate, so that the entire gland need not be treated. Finally, (3) ultrasound guidance for an eye plaque program is presented. US can be a key component of placement and QA for episcleral plaque brachytherapy for ocular cancer, and the UCLA eye plaque program with US for image guidance is presented to demonstrate the utility of US verification of plaque placement in improving the methods and QA in episcleral plaque brachytherapy. Learning Objectives: To understand the physics of an US system and the necessary aspects of commissioning US for image guided brachytherapy (IGBT). To understand real time planning of prostate HDR using ultrasound, and its application in partial prostate treatments using MR-ultrasound fusion to focus treatment on disease within the prostate. To understand the methods and QA in applying US for localizing the target and the implant during a episcleral plaque brachytherapy procedures.

  2. Brachytherapy for early oral tongue cancer. Low dose rate to high dose rate

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Hideya [Toyonaka Municipal Hospital, Osaka (Japan); Inoue, Takehiro; Yoshida, Ken; Yoshioka, Yasuo; Shimizutani, Kimishige; Inoue, Toshihiko [Osaka Univ., Suita (Japan). Graduate School of Medicine; Furukawa, Souhei; Kakimoto, Naoya [Osaka Univ., Suita (Japan). Graduate School of Dentistry

    2003-03-01

    To examine the compatibility of low dose rate (LDR) with high dose rate (HDR) brachytherapy, we reviewed 399 patients with early oral tongue cancer (T1-2N0M0) treated solely by brachytherapy at Osaka University Hospital between 1967 and 1999. For patients in the LDR group (n=341), the treatment sources consisted of Ir-192 pin for 227 patients (1973-1996; irradiated dose, 61-85 Gy; median, 70 Gy), Ra-226 needle for 113 patients (1967-1986; 55-93 Gy; median, 70 Gy). Ra-226 and Ir-192 were combined for one patient. Ir-192 HDR (microSelectron-HDR) was used for 58 patients in the HDR group (1991-present; 48-60 Gy; median, 60 Gy). LDR implantations were performed via oral and HDR via a submental/submandibular approach. The dose rates at the reference point for the LDR group were 0.30 to 0.8 Gy/h, and for the HDR group 1.0 to 3.4 Gy/min. The patients in the HDR group received a total dose of 48-60 Gy (8-10 fractions) during one week. Two fractions were administered per day (at least a 6-h interval). The 3- and 5-year local control rates for patients in the LDR group were 85% and 80%, respectively, and those in the HDR group were both 84%. HDR brachytherapy showed the same lymph-node control rate as did LDR brachytherapy (67% at 5 years). HDR brachytherapy achieved the same locoregional result as did LDR brachytherapy. A converting factor of 0.86 is applicable for HDR in the treatment of early oral tongue cancer. (author)

  3. The Royal College of Radiologists' audit of prostate brachytherapy in the year 2012.

    Science.gov (United States)

    Stewart, A J; Drinkwater, K J; Laing, R W; Nobes, J P; Locke, I

    2015-06-01

    This audit provides a comprehensive overview of UK prostate brachytherapy practice in the year 2012, measured against existing standards, immediately before the introduction of new Royal College of Radiologists (RCR) guidelines. This audit allows comparison with European and North American brachytherapy practice and for the impact of the RCR 2012 guidelines to be assessed in the future. A web-based data collection tool was developed by the RCR Clinical Audit Committee and sent to audit leads at all cancer centres in the UK. Standards were developed based on available guidelines in use at the start of 2012 covering case mix and dosimetry. Further questions were included to reflect areas of anticipated change with the implementation of the 2012 guidelines. Audit findings were compared with similar audits of practice in Europe, the USA and Latin America. Forty-nine of 59 cancer centres submitted data. Twenty-nine centres reported carrying out prostate brachytherapy; of these, 25 (86%) provided data regarding the number of implants, staffing, dosimetry, medication and anaesthesia and follow-up. Audit standards achieved excellent compliance in most areas, although were low in post-implant dosimetry and in post-implant scanning at 30 days. This audit provides a comprehensive picture of prostate brachytherapy in the UK in 2012. Patterns of care of prostate brachytherapy are similar to practice in the USA and Europe. The number of prostate brachytherapy implants carried out in the UK has grown significantly since a previous RCR audit in 2005 and it is important that centres maintain minimum numbers of cases to ensure that experience can be maintained and compliance to guidelines achieved. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  4. Brachytherapy for early oral tongue cancer: low dose rate to high dose rate.

    Science.gov (United States)

    Yamazaki, Hideya; Inoue, Takehiro; Yoshida, Ken; Yoshioka, Yasuo; Furukawa, Souhei; Kakimoto, Naoya; Shimizutani, Kimishige; Inoue, Toshihiko

    2003-03-01

    To examine the compatibility of low dose rate (LDR) with high dose rate (HDR) brachytherapy, we reviewed 399 patients with early oral tongue cancer (T1-2N0M0) treated solely by brachytherapy at Osaka University Hospital between 1967 and 1999. For patients in the LDR group (n = 341), the treatment sources consisted of Ir-192 pin for 227 patients (1973-1996; irradiated dose, 61-85 Gy; median, 70 Gy), Ra-226 needle for 113 patients (1967-1986; 55-93 Gy; median, 70 Gy). Ra-226 and Ir-192 were combined for one patient. Ir-192 HDR (microSelectron-HDR) was used for 58 patients in the HDR group (1991-present; 48-60 Gy; median, 60 Gy). LDR implantations were performed via oral and HDR via a submental/submandibular approach. The dose rates at the reference point for the LDR group were 0.30 to 0.8 Gy/h, and for the HDR group 1.0 to 3.4 Gy/min. The patients in the HDR group received a total dose of 48-60 Gy (8-10 fractions) during one week. Two fractions were administered per day (at least a 6-h interval). The 3- and 5-year local control rates for patients in the LDR group were 85% and 80%, respectively, and those in the HDR group were both 84%. HDR brachytherapy showed the same lymph-node control rate as did LDR brachytherapy (67% at 5 years). HDR brachytherapy achieved the same locoregional result as did LDR brachytherapy. A converting factor of 0.86 is applicable for HDR in the treatment of early oral tongue cancer.

  5. Microspheres with an ultra high holmium content for brachytherapy of malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Lira, Raphael A.; Myamoto, Douglas M.; Souza, Jaime R.; Nascimento, Nanci; Azevedo, Mariangela de Burgos M. de [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Biotecnologia; Osso Junior, Joao A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Radiofarmacia; Martinelli, Jose R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencias e Tecnologia de Materiais

    2011-07-01

    The overall objective of this work is to develop biodegradable microspheres intended for internal radiation therapy which provides an improved treatment for hepatic carcinomas. The most studied brachytherapy system employing microspheres made of holmium-biopolymer system is composed by poly(L-lactic acid) (PLLA) and holmium acetylacetonate (HoAcAc). The importance of the holmium high content in the microspheres can be interpreted as follow from a therapeutic standpoint, to achieve an effective use of microspheres loaded with HoAcAc, a high content of holmium is required to yield enough radioactivity with a relatively low amount of microspheres.The usual amounts of holmium that are incorporated in the microspheres composed by poly(L-lactic acid) and HoAcAc are 17.0 {+-} 0.5% (w/w) of holmium, which corresponds to a loading of about 50% of HoAcAc. Different approaches have been investigated to increase that value. One updated approach towards this direction is the production of microspheres with ultrahigh holmium as matrix using HoAcAc crystals as the sole starting material without the use of biopolymer. Likewise, in the search of microspheres with increased holmium content , it has been demonstrated that by changing the HoAcAc crystal structure by its recrystallization from crystal phase to the amorphous there is lost of acetylacetonate and water molecules causing the increasing of the holmium content. Microspheres were prepared by solvent evaporation, using holmium acetylacetonate (HoAcAc) crystals as the sole ingredient. Microspheres were characterized by using light and scanning electron microscopy, infrared and Raman spectroscopy, differential scanning calorimetry, X-rays diffraction, and confocal laser scanning microscopy. (author)

  6. Film dosimetry calibration method for pulsed-dose-rate brachytherapy with an 192Ir source.

    Science.gov (United States)

    Schwob, Nathan; Orion, Itzhak

    2007-05-01

    192Ir sources have been widely used in clinical brachytherapy. An important challenge is to perform dosimetric measurements close to the source despite the steep dose gradient. The common, inexpensive silver halide film is a classic two-dimensional integrator dosimeter and would be an attractive solution for these dose measurements. The main disadvantage of film dosimetry is the film response to the low-energy photon. Since the photon energy spectrum is known to vary with depth, the sensitometric curves are expected to be dependent on depth. The purpose of this study is to suggest a correction method for silver halide film dosimetry that overcomes the response changes at different depths. Sensitometric curves have been obtained at different depths with verification film near a 1 Ci 192Ir pulsed-dose-rate source. The depth dependence of the film response was observed and a correction function was established. The suitability of the method was tested through measurement of the radial dose profile and radial dose function. The results were compared to Monte Carlo-simulated values according to the TG43 formalism. Monte Carlo simulations were performed separately for the beta and gamma source emissions, using the EGS4 code system, including the low-energy photon and electron transport optimization procedures. The beta source emission simulation showed that the beta dose contribution could be neglected and therefore the film-depth dependence could not be attributed to this part of the source radioactivity. The gamma source emission simulations included photon-spectra collection at several depths. The results showed a depth-dependent softening of the photon spectrum that can explain the film-energy dependence.

  7. In vivo dosimetry thermoluminescence dosimeters during brachytherapy with a 370 GBq {sup 192}Ir source

    Energy Technology Data Exchange (ETDEWEB)

    Cuepers, S.; Piessens, M.; Verbeke, L.; Roelstraete, A. [Onze-Lieve-Vrouw Hospitaal, Aalst (Belgium). Dept. of Radiotherapy and Oncology

    1995-12-01

    When using LiF thermoluminescence dosimeters in brachytherapy, we have to take into account the properties of a high dose rate {sup 192}Ir source (energy spectrum ranging form 9 to 885 keV, steep dose gradient in the vicinity of the source) and these of the dosimeters themselves (supralinearity, reproducibility, size). All these characteristics combine into a set of correction factors which have been determined during in phantom measurements. These results have then been used to measure the dose delivered to organs at risk (e.g. rectum, bladder, etc.) during high dose rate brachytherapy with a 370 GBq {sup 192}Ir source for patients with gynaecological tumors.

  8. High dose-rate brachytherapy source position quality assurance using radiochromic film.

    Science.gov (United States)

    Evans, M D C; Devic, S; Podgorsak, E B

    2007-01-01

    Traditionally, radiographic film has been used to verify high-dose-rate brachytherapy source position accuracy by co-registering autoradiographic and diagnostic images of the associated applicator. Filmless PACS-based clinics that do not have access to radiographic film and wet developers may have trouble performing this quality assurance test in a simple and practical manner. We describe an alternative method for quality assurance using radiochromic-type film. In addition to being easy and practical to use, radiochromic film has some advantages in comparison with traditional radiographic film when used for HDR brachytherapy quality assurance.

  9. Endovascular brachytherapy to prevent restenosis after angioplasty; Endovaskulaere Brachytherapie in der Restenoseprophylaxe nach Angioplastie und Stentimplantation: Eine Uebersicht

    Energy Technology Data Exchange (ETDEWEB)

    Wohlgemuth, W.A.; Bohndorf, K. [Klinikum Augsburg (Germany). Klinik fuer Diagnostische Radiologie und Neuroradiologie

    2003-02-01

    Endovascular radiotherapy is the first effective prophylaxis of restenosis after percutaneous transluminal angioplasty (PTA) and stenting. The FDA recently approved two devices for the delivery of intracoronary radiation following coronary artery stenting. Published multicenter, double-blind, randomized trials of intracoronary radiation therapy report good results for preventing in-stent restenosis, while the data for the peripheral circulation are still inconclusive. Beta-emitters are easier applicable and probably also safer, whereas gamma-emitters have been more extensively evaluated clinically so far. Primary indication for endovascular brachytherapy are patients at high risk for restenosis, such as previous restenoses, in-stent hyperplasia, long stented segment, long PTA lesion, narrow residual vascular lumen and diabetes. Data from coronary circulation suggest a safety margin of at least 4 to 10 mm at both ends of the angioplastic segment to avoid edge restenosis. To prevent late thrombosis of the treated coronary segment, antiplatelet therapy with clopidogrel and aspirin are recommended for at least 6 months after PTA and for 12 months after a newly implanted stent. An established medication regimen after radiotherapy of peripheral arteries is still lacking. (orig.) [German] Die endovaskulaere Radiotherapie stellt das erste erfolgreiche Therapiekonzept in der Restenoseprophylaxe nach PTA und Stentimplantation dar. Am 3.11.2000 hat die amerikanische Food and Drug Administration erstmalig zwei Brachytherapiegeraete zur Restenoseprophylaxe nach Koronararterien-Stenting zugelassen. Grosse multizentrische, kontrollierte Studien wurden fuer das koronare Stromgebiet mit positiven Ergebnissen publiziert, die Datenlage im peripheren Stromgebiet ist noch ungenuegend. Beta-Strahler bieten Vorteile in der Anwendung, moeglicherweise auch in der Sicherheit, Gamma-Strahler dagegen sind besser klinisch evaluiert. Die primaere Indikation zur endovaskulaeren Brachytherapie

  10. Transradial coronary brachytherapy with the Novoste Beta-Rail system.

    Science.gov (United States)

    Bertrand, Olivier F; De Larochellière, Robert; Gleeton, Onil; Plante, Sylvain; Tessier, Michel; Guimond, Jean

    2002-03-01

    We report our initial experience in 10 consecutive patients who underwent transradial coronary brachytherapy for in-stent restenosis using a 90Sr/Y source and the Novoste Beta-Rail system. In all patients, procedures were successfully completed using a right transradial approach. We performed the procedures with the Beta-Rail catheter using 7 Fr (Zuma II, Medtronic, MN; n = 5) or 8 Fr (Cordis, Miami, FL; n = 5) guiding catheters. All lesions were successfully dilated and no additional stent was inserted. We used a 40 mm source (n = 3) or a 60 mm source (n = 7) with manual stepping in four cases. In three cases, we did one stepping, and in one case, we did three steppings. The mean dwell time was 195 plus minus 44 sec. The mean delivered dose was 23 +/- 3 Gy at 2 mm distance from the source. No radiation treatment was interrupted. Mean fluoroscopy time was 26 +/- 13 min. Procedural success was achieved in all patients. Three patients had mild CK elevations (< 3 times upper normal limit). All patients were pretreated with clopidogrel (300 mg) and combined treatment with aspirin + clopidogrel is to be continued for at least 1 year. Clinical follow-up up to 3 months has not yielded any complication and all patients have remained free from angina.

  11. Pedicle versus free flap reconstruction in patients receiving intraoperative brachytherapy.

    Science.gov (United States)

    Geiger, Erik J; Basques, Bryce A; Chang, Christopher C; Son, Yung; Sasaki, Clarence T; McGregor, Andrew; Ariyan, Stephan; Narayan, Deepak

    2016-08-01

    Introduction This study compared complication rates between pedicle flaps and free flaps used for resurfacing of intraoperative brachytherapy (IOBT) implants placed following head and neck tumour extirpation to help clarify the ideal reconstructive procedure for this scenario. Patients and methods A retrospective review of reconstructions with IOBT at our institution was conducted. Patient and treatment details were recorded, as were the number and type of flap complications, including re-operations. Logistic regressions compared complications between flap groups. Results Fifty free flaps and 55 pedicle flaps were included. On multivariate analysis, free flap reconstruction with IOBT was significantly associated with both an increased risk of having any flap complication (OR = 2.9, p = 0.037) and with need for operative revision (OR = 3.5, p = 0.048) compared to pedicle flap reconstruction. Conclusions In the setting of IOBT, free flaps are associated with an increased risk of having complications and requiring operative revisions.

  12. Application of spherical micro diodes for brachytherapy dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Broisman, Andrey, E-mail: andreybr@ariel.ac.i [Medical Physics, Ariel University Center, Ariel 40700 (Israel); Shani, Gad [Biomedical Engineering, Ben Gurion University, P.O. Box 653, Beer Sheva 84105 (Israel)

    2011-03-15

    The research presented in this paper demonstrates the feasibility and the advantages of using spherical micro diodes for radiation dosimetry. The spherical symmetry of the diode response is demonstrated, compared to that of planar diodes. The application of the spherical diode described here is for radiotherapy dosimetry, particularly brachytherapy. Measurements were done in PMMA phantoms. The advantage of the spherical diode is that it can be used for radiation measurement in a 4{pi} geometry, it was demonstrated by measurements in both axial and azimuthal planes. The diodes were found to respond equally to radiation coming from all directions, directly from the source or due to scattered radiation within the medium. In the present work 1.8 mm diameter silicone diodes were used. The small size of these spherical diodes provides local dose measurement and can be used for in situ dosimetry while treatment takes place. Treatment planning correction can be made accordingly. Commercially available seeds of the isotopes I{sup 125} and Pd{sup 103} were used as radiation sources. The spherical diodes response was compared with that of planar diodes XRB generally used for UV and X-ray dosimetry, and with TLD measurements. We have also compared the measured results with Monte Carlo simulation, applying the MCNP code and with calculations shown in the TG-43 report.

  13. MRI/TRUS data fusion for prostate brachytherapy. Preliminary results

    CERN Document Server

    Reynier, Christophe; Fourneret, Philippe; Dusserre, André; Gay-Jeune, Cécile; Descotes, Jean-Luc; Bolla, Michel; Giraud, Jean-Yves

    2008-01-01

    Prostate brachytherapy involves implanting radioactive seeds (I125 for instance) permanently in the gland for the treatment of localized prostate cancers, e.g., cT1c-T2a N0 M0 with good prognostic factors. Treatment planning and seed implanting are most often based on the intensive use of transrectal ultrasound (TRUS) imaging. This is not easy because prostate visualization is difficult in this imaging modality particularly as regards the apex of the gland and from an intra- and interobserver variability standpoint. Radioactive seeds are implanted inside open interventional MR machines in some centers. Since MRI was shown to be sensitive and specific for prostate imaging whilst open MR is prohibitive for most centers and makes surgical procedures very complex, this work suggests bringing the MR virtually in the operating room with MRI/TRUS data fusion. This involves providing the physician with bi-modality images (TRUS plus MRI) intended to improve treatment planning from the data registration stage. The pape...

  14. Development of irradiation support devices for production of brachytherapy seeds

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Fabio R.; Rostelato, Maria Elisa C.M.; Zeituni, Carlos A.; Souza, Carla D.; Moura, Joao A.; Peleias Junior, Fernando S.; Karan Junior, Dib; Feher, Anselmo; Oliveira, Tiago B.; Benega, Marcos A.G., E-mail: tiagooliveira298@gmail.com, E-mail: mattos.fr@gmail.com, E-mail: elisaros@ipen.br, E-mail: czeituni@ipen.br, E-mail: carladdsouza@yahoo.com.br, E-mail: jamoura@ipen.br, E-mail: ernandopeleias@gmail.com, E-mail: s, E-mail: dib.karan@usp.br, E-mail: afeher@ipen.br, E-mail: marcosagbenega@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Ophthalmic tumors treatment with brachytherapy sources has been widely used as a primary or secondary therapy for non-malignant or malignant tumors, for example, choroid melanoma, and retinoblastoma. Ruthenium-106, Iodine-125, Palladium -103, Gold-198 and Iridium-192, are some radionuclides that can be applied for treatment of ocular tumors. These sources are in small sizes (a few millimeters) and different shapes (rods, wires, disks). To ensure high accuracy during treatment, they are positioned in eye applicators, specially designed to fit on the surface of tumor. The Nuclear and Energy Research Institute (IPEN/CNEN) in a partnership with Paulista Medicine School (UNIFESP) created a project that aims to develop a prototype of Iridium-192 seeds for treatment of eye cancer. This seed consists in a core of Ir -Pt alloy (20%-80%) with a length of 3 mm, to be activated in IPEN's IEA-R1 Reactor, and a titanium capsule sealing the core. It was imperative to develop a sustainer device for irradiation. This piece is used to avoid overlapping of one cores and, therefore, avoiding the 'shadow effect' that does not allow full activation of each core due to the high density. (author)

  15. Monte Carlo evaluation of kerma in an HDR brachytherapy bunker

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Calatayud, J [Department of Atomic, Molecular and Nuclear Physics, and IFIC, CSIC-University of Valencia, Burjassot (Spain); Granero, D [Department of Atomic, Molecular and Nuclear Physics, and IFIC, CSIC-University of Valencia, Burjassot (Spain); Ballester, F [Department of Atomic, Molecular and Nuclear Physics, and IFIC, CSIC-University of Valencia, Burjassot (Spain); Casal, E [Department of Atomic, Molecular and Nuclear Physics, and IFIC, CSIC-University of Valencia, Burjassot (Spain); Crispin, V [FIVO, Fundacion Instituto Valenciano De OncologIa, Valencia (Spain); Puchades, V [Grupo IMO-SFA, Madrid (Spain); Leon, A [Department of Chemistry and Nuclear Engineering, Polytechnic University of Valencia, Valencia (Spain); Verdu, G [Department of Chemistry and Nuclear Engineering, Polytechnic University of Valencia, Valencia (Spain)

    2004-12-21

    In recent years, the use of high dose rate (HDR) after-loader machines has greatly increased due to the shift from traditional Cs-137/Ir-192 low dose rate (LDR) to HDR brachytherapy. The method used to calculate the required concrete and, where appropriate, lead shielding in the door is based on analytical methods provided by documents published by the ICRP, the IAEA and the NCRP. The purpose of this study is to perform a more realistic kerma evaluation at the entrance maze door of an HDR bunker using the Monte Carlo code GEANT4. The Monte Carlo results were validated experimentally. The spectrum at the maze entrance door, obtained with Monte Carlo, has an average energy of about 110 keV, maintaining a similar value along the length of the maze. The comparison of results from the aforementioned values with the Monte Carlo ones shows that results obtained using the albedo coefficient from the ICRP document more closely match those given by the Monte Carlo method, although the maximum value given by MC calculations is 30% greater. (note)

  16. How one institution overcame the challenges to start an MRI-based brachytherapy program for cervical cancer

    Directory of Open Access Journals (Sweden)

    Matthew M. Harkenrider

    2017-03-01

    Full Text Available Purpose : Adaptive magnetic resonance imaging (MRI-based brachytherapy results in improved local control and decreased high-grade toxicities compared to historical controls. Incorporating MRI into the workflow of a department can be a major challenge when initiating an MRI-based brachytherapy program. This project aims to describe the goals, challenges, and solutions when initiating an MRI-based cervical cancer brachytherapy program at our institution. Material and methods : We describe the 6-month multi-disciplinary planning phase to initiate an MRI-based brachytherapy program. We describe the specific challenges that were encountered prior to treating our first patient. Results : We describe the solutions that were realized and executed to solve the challenges that we faced to establish our MRI-based brachytherapy program. We emphasize detailed coordination of care, planning, and communication to make the workflow feasible. We detail the imaging and radiation physics solutions to safely deliver MRI-based brachytherapy. The focus of these efforts is always on the delivery of optimal, state of the art patient care and treatment delivery within the context of our available institutional resources. Conclusions : Previous publications have supported a transition to MRI-based brachytherapy, and this can be safely and efficiently accomplished as described in this manuscript.

  17. Simultaneous radiochemotherapy and endoluminal HDR brachytherapy in esophageal cancer; Simultane Radiochemotherapie mit intraluminaler HDR-Brachytherapie des Oesophaguskarzinoms

    Energy Technology Data Exchange (ETDEWEB)

    Patonay, P.; Naszaly, A.; Mayer, A. [Hauptstaedtisches Zentrum fuer Radioonkologie und Strahlentherapie, Budapest (Hungary)

    2007-02-15

    Purpose: to study efficacy and toxicity of radiochemotherapy in esophageal cancer including initial endoluminal high-dose-rate brachytherapy (HDR-BT). Patients and methods: between 01/1995 and 06/2005, 61 patients with esophageal cancer were treated preoperatively with definitive and palliative intent. Treatment started with intraluminal HDR-BT for recanalization of the esophagus (single fraction size of 8 Gy in 0.5 cm depth, three times, q7d) followed by external-beam radiation therapy (50 Gy total dose, 5 x 2 Gy/week, 25 fractions in 5 weeks). Chemotherapy was started simultaneously with external irradiation (three courses of cisplatin and 5-fluorouracil, q21d). Results: swallowing function improved in 55/61 patients (dysphagia classification according to the RTOG), and worsened in 6/61 patients, respectively. Median duration of symptomatic improvement was 11 months, median follow-up 12 months (range 3-68 months). Following simultaneous radiochemotherapy, tumor resectability was achieved in 7/25 patients of the neoadjuvant group, and the histological specimen showed complete remission in 6/7 patients. Conclusion: these results indicate a favorable effect of simultaneous radiochemotherapy starting with endoluminal HDR-after-loading-(AL-)BT in esophageal cancer. (orig.)

  18. Asymmetric dose-volume optimization with smoothness control for rotating-shield brachytherapy.

    Science.gov (United States)

    Liu, Yunlong; Flynn, Ryan T; Kim, Yusung; Wu, Xiaodong

    2014-11-01

    It is important to reduce fluence map complexity in rotating-shield brachytherapy (RSBT) inverse planning to improve delivery efficiency while maintaining plan quality. This study proposes an efficient and effective RSBT dose optimization method which enables to produce smooth fluence maps. Five cervical cancer patients each with a high-risk clinical-target-volume (HR-CTV) larger than 40 cm(3) were considered as the test cases. The RSBT source was a partially shielded electronic brachytherapy source (Xoft Axxent™). The anchor RSBT plans generated by the asymmetric dose-volume optimization with smoothness control (ADOS) method were compared against those produced by the dose-surface optimization (DSO) method and inverse-planning with simulated annealing (IPSA). Either L1-norm or L2-norm was used to measure the smoothness of a fluence map in the proposed ADOS method as one weighted term of the objective function. Uniform dwell-time scaling was applied to all plans such that HR-CTV D90 was maximized without violating the D2cc tolerances of the rectum, bladder, and sigmoid colon. The quality of the anchor plans was measured with HR-CTV D90 of the anchor plans. Single-shielded RSBT [(S-RSBT), RSBT with single, fix sized delivery window] and dynamic-sheilded RSBT [(D-RSBT), RSBT with dynamically varying sized delivery window] delivery plans generated based on the anchor plans were also measured, with delivery time constraints of 10, 20, and 30 min/fraction (fx). The average HR-CTV D90 values of the anchor plans achieved by the ADOS, DSO, and IPSA methods were 111.5, 94.2, and 107.4 Gy, respectively, where the weighting parameter β used in ADOS with L2-norm was set to be 100. By using S-RSBT sequencing and 20 min/fx delivery time, the corresponding D90 values were 88.8, 81.9, and 83.4 Gy; while using D-RSBT sequencing with 20 min/fx delivery time, the corresponding D90 values were 91.4, 88.3, and 78.9 Gy, respectively. The average optimization times for ADOS, DSO, and

  19. Asymmetric dose–volume optimization with smoothness control for rotating-shield brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yunlong [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 (United States); Flynn, Ryan T.; Kim, Yusung [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Wu, Xiaodong, E-mail: xiaodong-wu@uiowa.edu [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 and Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States)

    2014-11-01

    Purpose: It is important to reduce fluence map complexity in rotating-shield brachytherapy (RSBT) inverse planning to improve delivery efficiency while maintaining plan quality. This study proposes an efficient and effective RSBT dose optimization method which enables to produce smooth fluence maps. Methods: Five cervical cancer patients each with a high-risk clinical-target-volume (HR-CTV) larger than 40 cm{sup 3} were considered as the test cases. The RSBT source was a partially shielded electronic brachytherapy source (Xoft Axxent™). The anchor RSBT plans generated by the asymmetric dose–volume optimization with smoothness control (ADOS) method were compared against those produced by the dose–surface optimization (DSO) method and inverse-planning with simulated annealing (IPSA). Either L{sub 1}-norm or L{sub 2}-norm was used to measure the smoothness of a fluence map in the proposed ADOS method as one weighted term of the objective function. Uniform dwell-time scaling was applied to all plans such that HR-CTV D{sub 90} was maximized without violating the D{sub 2cc} tolerances of the rectum, bladder, and sigmoid colon. The quality of the anchor plans was measured with HR-CTV D{sub 90} of the anchor plans. Single-shielded RSBT [(S-RSBT), RSBT with single, fix sized delivery window] and dynamic-sheilded RSBT [(D-RSBT), RSBT with dynamically varying sized delivery window] delivery plans generated based on the anchor plans were also measured, with delivery time constraints of 10, 20, and 30 min/fraction (fx). Results: The average HR-CTV D{sub 90} values of the anchor plans achieved by the ADOS, DSO, and IPSA methods were 111.5, 94.2, and 107.4 Gy, respectively, where the weighting parameter β used in ADOS with L{sub 2}-norm was set to be 100. By using S-RSBT sequencing and 20 min/fx delivery time, the corresponding D{sub 90} values were 88.8, 81.9, and 83.4 Gy; while using D-RSBT sequencing with 20 min/fx delivery time, the corresponding D{sub 90} values were

  20. CT-guided brachytherapy. A novel percutaneous technique for interstitial ablation of liver malignancies; CT-gesteuerte Brachytherapie. Eine neue perkutane Technik zur interstitiellen Ablation von Lebermetastasen

    Energy Technology Data Exchange (ETDEWEB)

    Ricke, J.; Wust, P.; Stohlmann, A.; Beck, A.; Cho, C.H.; Pech, M.; Wieners, G.; Spors, B.; Werk, M.; Rosner, C.; Haenninen, E.L.; Felix, R. [Klinik fuer Strahlenheilkunde, Charite Virchow-Klinikum, Humboldt-Univ. zu Berlin (Germany)

    2004-05-01

    Purpose: to assess safety and efficacy of CT-guided brachytherapy of liver malignancies. Patients and methods: 21 patients with 21 liver malignancies (19 metastases, two primary liver tumors) were treated with interstitial CT-guided brachytherapy applying a {sup 192}Ir source. In all patients, the use of image-guided thermal tumor ablation such as by radiofrequency or laser-induced thermotherapy (LITT) was impeded either by tumor size {>=} 5 cm in seven, adjacent portal or hepatic vein in ten, or adjacent bile duct bifurcation in four patients. Dosimetry was performed using three-dimensional CT data sets acquired after CT-guided positioning of the brachytherapy catheters. Results: the mean tumor diameter was 4.6 cm (2.5-11 cm). The mean minimal tumor dose inside the tumor margin amounted to 17 Gy (12-20 Gy). The proportion of the liver parenchyma exposed to > 5 gy was 18% (5-39%) of total liver parenchyma minus tumor volume. Nausea and vomiting were observed in six patients after brachytherapy (28%). One patient demonstrated obstructive jaundice due to tumor edema after irradiation of a metastasis adjacent to the bile duct bifurcation. We commonly encountered asymptomatic increases of liver enzymes. Local control rates after 6 and 12 months were 87% and 70%, respectively. Conclusion: CT-guided brachytherapy is safe and effective. This technique displays broader indications compared to image-guided thermal ablation by radiofrequency or LITT with respect to tumor size or localization. (orig.) [German] Ziel: Analyse der Sicherheit und Effektivitaet CT-gesteuerter Brachytherapie zur Ablation von Lebermalignomen. Patienten und Methodik: 21 Patienten mit 21 Lebermalignomen (19 Metastasen, zwei primaere Lebermalignome) wurden mit perkutaner, CT-gesteuerter interstitieller Brachytherapie mit {sup 192}Ir behandelt. Alle Patienten wiesen Umstaende auf, die eine bildgefuehrte thermische Ablation mit Radiofrequenz oder laserinduzierter Thermotherapie (LITT) einschraenkten

  1. CT computer-optimized high-dose-rate brachytherapy with surface applicator technique for scar boost radiation after breast reconstruction surgery.

    Science.gov (United States)

    Stewart, Alexandra J; O'Farrell, Desmond A; Bellon, Jennifer R; Hansen, Jorgen L; Duggan, Catherine; Czerminska, Maria A; Cormack, Robert A; Devlin, Phillip M

    2005-01-01

    Immediate breast reconstruction has become increasingly prevalent after mastectomy for breast cancer. Postoperative scar boost radiation for the reconstructed breast presents many planning challenges due to the shape, size, and curvature of the scar. High-dose-rate (HDR) surface applicator brachytherapy is a novel and effective method of delivering scar boost radiation. Two cases, one with a saline implant and one with a transverse rectus abdominis musculocutaneous flap reconstruction, illustrate the method and advantages of HDR optimization of surface applicators. For 2 patients a mold of the breast was made with Aquaplast sheets. A reproducible system was used for arm positioning. Skin fiducials, including tattoos from external beam planning, were matched to fiducials on the mold. HDR catheters were sited on the mold at 1cm intervals, with the central catheter situated along the scar. Topographically, both scars demonstrated extreme curvature in both craniocaudal and mediolateral directions. A CT computer-optimized HDR plan was developed, with the reference dose prescribed at the skin surface. The dosimetry was compared to single-field and matched-field electron plans. This surface applicator technique provided a uniform skin dose of 100% to the entire clinical target volume (CTV) without hot spots in both patients. The patient position and surface applicator setup were consistently reproducible. The patients tolerated the treatment well with minimal skin erythema. In the single-field electron plan, skin dose was decreased to 50% at the periphery of the scar. Matching fields addressed this depth dose decrement, but resulted in large localized hot spots of more than 200% centrally in each field. CT computer-optimized HDR surface applicator brachytherapy provided a reproducible homogeneous method of treating highly curved scars on the reconstructed breast. Electron beam treatment would result in longer and more complex treatments yet still provide a less

  2. The use of trans-applicator intracavitary ultrasonography in brachytherapy for cervical cancer: phantom study of a novel approach to 3D image-guided brachytherapy.

    Science.gov (United States)

    Tamaki, Tomoaki; Miyaura, Kazunori; Murakami, Toshihiro; Kumazaki, Yu; Suzuki, Yoshiyuki; Nakano, Takashi; Kato, Shingo

    2017-04-01

    To assess the feasibility of applying trans-applicator intracavitary ultrasonography to image-guided brachytherapy for cervical cancer. For this experiment, a phantom was created and included a polyethylene tube, intended to simulate a tandem applicator, which was inserted into chicken meat and embedded in agar, along with magnetic resonance imaging (MRI)-compatible ovoid applicators. Three-dimensional images of the phantom were obtained using computed tomography (CT), MRI (T2-weighted), and intracavitary ultrasonography sectional images acquired at 1 mm slice intervals. Intracavitary ultrasonography images were acquired from within the simulated tandem applicator using a radial transducer. Magnetic resonance imaging and intracavitary ultrasonography images were manually registered onto CT images. The chicken meat was contoured as the target volume independently on the CT, MRI, and intracavitary ultrasonography images, and the Dice similarity coefficient was used to compare the target volumes. The dose distributions of a sample brachytherapy plan were also evaluated. Computed tomography, MRI, and intracavitary ultrasonography all visualized the three-dimensional phantom volumes. Intracavitary ultrasonography images depicted the meat with high echoic signals and a border clearly distinguishable from the surrounding agar. The Dice similarity coefficient values for the target volumes on CT vs. MRI, CT vs. intracavitary ultrasonography, and MRI vs. intracavitary ultrasonography were 0.966, 0.965, and 0.971, respectively, indicating similar contouring with the three modalities. Among the modalities, the differences in D50, D90, D98, and D100 values were 1.8%, 2.9%, 3.7%, and 2.9%, respectively. Three-dimensional reconstructed trans-applicator intracavitary ultrasonographic images clearly depicted meat tissue within the phantom, and could thus be used for brachytherapy planning. This study proves the concept of trans-applicator intracavitary ultrasonography for

  3. Interactive multiobjective optimization for anatomy-based three-dimensional HDR brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Ruotsalainen, Henri [Department of Physics and Mathematics, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio (Finland); Miettinen, Kaisa [Department of Mathematical Information Technology, PO Box 35 (Agora), FI-40014 University of Jyvaeskylae (Finland); Palmgren, Jan-Erik; Lahtinen, Tapani, E-mail: henrimatias.ruotsalainen@gmail.co [Department of Oncology, Kuopio University Hospital, PO Box 1777, FI-70211 Kuopio (Finland)

    2010-08-21

    In this paper, we present an anatomy-based three-dimensional dose optimization approach for HDR brachytherapy using interactive multiobjective optimization (IMOO). In brachytherapy, the goals are to irradiate a tumor without causing damage to healthy tissue. These goals are often conflicting, i.e. when one target is optimized the other will suffer, and the solution is a compromise between them. IMOO is capable of handling multiple and strongly conflicting objectives in a convenient way. With the IMOO approach, a treatment planner's knowledge is used to direct the optimization process. Thus, the weaknesses of widely used optimization techniques (e.g. defining weights, computational burden and trial-and-error planning) can be avoided, planning times can be shortened and the number of solutions to be calculated is small. Further, plan quality can be improved by finding advantageous trade-offs between the solutions. In addition, our approach offers an easy way to navigate among the obtained Pareto optimal solutions (i.e. different treatment plans). When considering a simulation model of clinical 3D HDR brachytherapy, the number of variables is significantly smaller compared to IMRT, for example. Thus, when solving the model, the CPU time is relatively short. This makes it possible to exploit IMOO to solve a 3D HDR brachytherapy optimization problem. To demonstrate the advantages of IMOO, two clinical examples of optimizing a gynecologic cervix cancer treatment plan are presented.

  4. Current situation of high-dose-rate brachytherapy for cervical cancer in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Rogerio Matias Vidal da; Souza, Divanizia do Nascimento, E-mail: rmv.fisica@gmail.com [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil); Pinezi, Juliana Castro Dourado [Pontificia Universidade Catolica de Goias (PUC-Goias), Goiania, GO (Brazil); Macedo, Luiz Eduardo Andrade [Hospital Chama, Arapiraca, AL (Brazil)

    2014-05-15

    To assess the current situation of high-dose-rate (HDR) brachytherapy for cancer of the cervix in Brazil, regarding apparatuses, planning methods, prescription, fractionation schedule and evaluation of dose in organs at risk. Materials and methods: in the period between March/2012 and May/2013, a multiple choice questionnaire was developed and sent to 89 Brazilian hospitals which perform HDR brachytherapy. Results: sixty-one services answered the questionnaire. All regions of the country experienced a sharp increase in the number of HDR brachytherapy services in the period from 2001 to 2013. As regards planning, although a three-dimensional planning software was available in 91% of the centers, conventional radiography was mentioned by 92% of the respondents as their routine imaging method for such a purpose. Approximately 35% of respondents said that brachytherapy sessions are performed after teletherapy. The scheme of four 7 Gy intracavitary insertions was mentioned as the most frequently practiced. Conclusion: the authors observed that professionals have difficulty accessing adjuvant three-dimensional planning tools such as computed tomography and magnetic resonance imaging. (author)

  5. ``In Vivo'' Dosimetry in High Dose Rate Brachytherapy for Cervical Cancer Treatments

    Science.gov (United States)

    González-Azcorra, S. A.; Mota-García, A.; Poitevín-Chacón, M. A.; Santamaría-Torruco, B. J.; Rodríguez-Ponce, M.; Herrera-Martínez, F. P.; Gamboa de Buen, I.; Ruíz-Trejo, C.; Buenfil, A. E.

    2008-08-01

    In this prospective study, rectal dose was measured "in vivo" using TLD-100 crystals (3×3×1 mm3), and it has been compared to the prescribed dose. Measurements were performed in patients with cervical cancer classified in FIGO stages IB-IIIB and treated with high dose rate brachytherapy (HDR BT) at the Instituto Nacional de Cancerología (INCan).

  6. Determination of the tissue inhomogeneity correction in high dose rate Brachytherapy for Iridium-192 source

    Directory of Open Access Journals (Sweden)

    Barlanka Ravikumar

    2012-01-01

    Full Text Available In Brachytherapy treatment planning, the effects of tissue heterogeneities are commonly neglected due to lack of accurate, general and fast three-dimensional (3D dose-computational algorithms. In performing dose calculations, it is assumed that the tumor and surrounding tissues constitute a uniform, homogeneous medium equivalent to water. In the recent past, three-dimensional computed tomography (3D-CT based treatment planning for Brachytherapy applications has been popularly adopted. However, most of the current commercially available planning systems do not provide the heterogeneity corrections for Brachytherapy dosimetry. In the present study, we have measured and quantified the impact of inhomogeneity caused by different tissues with a 0.015 cc ion chamber. Measurements were carried out in wax phantom which was employed to measure the heterogeneity. Iridium-192 (192 Ir source from high dose rate (HDR Brachytherapy machine was used as the radiation source. The reduction of dose due to tissue inhomogeneity was measured as the ratio of dose measured with different types of inhomogeneity (bone, spleen, liver, muscle and lung to dose measured with homogeneous medium for different distances. It was observed that different tissues attenuate differently, with bone tissue showing maximum attenuation value and lung tissue resulting minimum value and rest of the tissues giving values lying in between those of bone and lung. It was also found that inhomogeneity at short distance is considerably more than that at larger distances.

  7. Clinical outcomes following 3D image-guided brachytherapy for vaginal recurrence of endometrial cancer.

    Science.gov (United States)

    Lee, Larissa J; Damato, Antonio L; Viswanathan, Akila N

    2013-12-01

    To evaluate clinical outcomes for women with recurrent endometrial cancer treated with 3D image-guided brachytherapy 44 women, of whom 13 had received prior RT, received salvage RT for vaginal recurrence from 9/03 to 8/11. HDR or LDR interstitial brachytherapy was performed under MR or CT guidance in 35 patients (80%); 9 (20%) had CT-guided HDR cylinder brachytherapy. The median cumulative dose in EQD2 was 75.5 Gy. Actuarial estimates of local failure (LF), disease-free (DFS) and overall survival (OS) were calculated by Kaplan-Meier. Histologic subtypes were endometrioid (EAC, 33), papillary serous/clear cell (UPSC/CC, 5) and carcinosarcoma (CS, 6). The 2-year DFS/OS rates were 75%/89% for EAC and 11%/24% for UPSC/CC/CS (both pradiotherapy. 3D image-guided brachytherapy results in excellent local control for women with recurrent endometrial cancer, particularly with cumulative EQD2 doses greater than 70 Gy. Successful salvage of vaginal recurrence is related to tumor grade and histologic subtype. © 2013.

  8. Perioperative Interstitial High-Dose-Rate Brachytherapy for the Treatment of Recurrent Keloids

    DEFF Research Database (Denmark)

    Jiang, Ping; Baumann, René; Dunst, Juergen;

    2016-01-01

    PURPOSE: To prospectively evaluate high-dose-rate brachytherapy in the treatment of therapy-resistant keloids and report first results, with emphasis on feasibility and early treatment outcome. METHODS AND MATERIALS: From 2009 to 2014, 24 patients with 32 recurrent keloids were treated with immed...

  9. Individualised 3D printed vaginal template for MRI guided brachytherapy in locally advanced cervical cancer

    DEFF Research Database (Denmark)

    Lindegaard, Jacob Christian; Lænsø Madsen, Mads; Hansen, Anders Traberg

    2016-01-01

    Intracavitary–interstitial applicators for MRI guided brachytherapy are becoming increasingly important in locally advanced cervical cancer. The 3D printing technology enables a versatile method for obtaining a high degree of individualisation of the implant. Our clinical workflow is presented...

  10. Comparison of 60Co and 192Ir sources in HDR brachytherapy

    Directory of Open Access Journals (Sweden)

    Grzegorz Zwierzchowski

    2011-12-01

    Full Text Available This paper compares the isotopes 60Co and 192Ir as radiation sources for high-dose-rate (HDR afterloadingbrachytherapy. The smaller size of 192Ir sources made it the preferred radionuclide for temporary brachytherapy treatments.Recently also 60Co sources have been made available with identical geometrical dimensions. This paper comparesthe characteristics of both nuclides in different fields of brachytherapy based on scientific literature. In an additionalpart of this paper reports from medical physicists of several radiation therapy institutes are discussed. The purposeof this work is to investigate the advantages or disadvantages of both radionuclides for HDR brachytherapy due to theirphysical differences. The motivation is to provide useful information to support decision-making procedures in theselection of equipment for brachytherapy treatment rooms. The results of this work show that no advantages or disadvantagesexist for 60Co sources compared to 192Ir sources with regard to clinical aspects. Nevertheless, there are potentiallogistical advantages of 60Co sources due to its longer half-life (5.3 years vs. 74 days, making it an interesting alternativeespecially in developing countries.

  11. Perineal recurrence of prostate cancer six years after trans-perineal brachytherapy

    NARCIS (Netherlands)

    Eppinga, Wietse; Vijverberg, Peter; Moerland, Rien; Brand, Eric; van der Voort van Zyp, Jochem; Noteboom, Juus; van Vulpen, Marco

    2015-01-01

    We report a case of perineal recurrence of prostate cancer 6 years after low-dose-rate (LDR) brachytherapy for localized prostate cancer. The most common approach to treat such perineal masses, including those occurring after prior biopsy or surgery, is local excision. We report the use of stereotac

  12. Incidence and prediction of seed migration to the chest after iodine-125 brachytherapy for hepatocellular carcinoma.

    Science.gov (United States)

    Lin, Junqing; Yang, Weizhu; Jiang, Na; Zheng, Qubin; Huang, Jingyao; Huang, Ning; Li, Ang; Jiang, Han

    2017-08-08

    The aims were to determine the incidence of seed migration to the chest and to analyze the predictive factors after iodine-125 brachytherapy for hepatocellular carcinoma. Three hundred ninety-nine patients with hepatocellular carcinoma underwent iodine-125 seed brachytherapy. After seed implantation, chest X-ray radiograph or computerized tomography were undertaken to assess the occurrence and location of seed migration at 3 months after brachytherapy. The incidence of seed migration to the lung and heart was calculated. A statistical analysis of the influences of seed loss to the chest was performed between patients with and without seed migration. A total of 13,977 seeds were implanted in 399 patients. One hundred fifty of the 13,977 (1.07%) seeds migrated to the chest in 81 of the 399 (20.30%) patients. Of all the migrated seeds, 112 (74.67%) migrated to the lungs in 59 (67.82%) patients, and 38 (25.33%) seeds migrated to the heart in 28 (47.46%) patients. No case exhibited clinical symptoms related to the migrated seeds. The number of seeds implanted and the number of seed implantations were significantly associated with seed migration. The occurrence of seed migration to the lungs and heart was evaluated. Furthermore, the number of seeds implanted and the number of seed implantation procedures are significant predictors of seed migration. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  13. Surface membrane based bladder registration for evaluation of accumulated dose during brachytherapy in cervical cancer

    DEFF Research Database (Denmark)

    Noe, Karsten Østergaard; Tanderup, Kari; Sørensen, Thomas Sangild

    2011-01-01

    of the fixed surface. Optional landmark based matches can be included in the suggested iterative solver. The technique is demonstrated for bladder registration in brachytherapy treatment evaluation of cervical cancer. It holds promise to better estimate the accumulated but unintentional dose delivered...

  14. Monte Carlo Simulation of Dosimetric Parameters for HYBRID PdI Source in Brachytherapy

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A novel brachytherapy source model, ADVANTAGE HYBRID PdI, has been designed by CIAE For treatment of cancer. In this project, the purpose of this study is to obtain the dosimetric parameters of HYBRID PdI source. The Monte Carlo simulation

  15. Impact of delineation uncertainties on dose to organs at risk in CT-guided intracavitary brachytherapy.

    LENUS (Irish Health Repository)

    Duane, Frances K

    2014-08-07

    This study quantifies the inter- and intraobserver variations in contouring the organs at risk (OARs) in CT-guided brachytherapy (BT) for the treatment of cervical carcinoma. The dosimetric consequences are reported in accordance with the current Gynecological Groupe Européen de Curiethérapie\\/European Society for Therapeutic Radiology and Oncology guidelines.

  16. Individualised 3D printed vaginal template for MRI guided brachytherapy in locally advanced cervical cancer.

    Science.gov (United States)

    Lindegaard, Jacob Christian; Madsen, Mikkel Lænsø; Traberg, Anders; Meisner, Bjarne; Nielsen, Søren Kynde; Tanderup, Kari; Spejlborg, Harald; Fokdal, Lars Ulrik; Nørrevang, Ole

    2016-01-01

    Intracavitary-interstitial applicators for MRI guided brachytherapy are becoming increasingly important in locally advanced cervical cancer. The 3D printing technology enables a versatile method for obtaining a high degree of individualisation of the implant. Our clinical workflow is presented and exemplified by a stage IVA cervical cancer with superior dose distribution.

  17. A gEUD-based inverse planning technique for HDR prostate brachytherapy: Feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Giantsoudi, D. [Department of Radiological Sciences, University of Texas Health Sciences Center, San Antonio, Texas 78229 (United States); Department of Radiation Oncology, Francis H. Burr Proton Therapy Center, Boston, Massachusetts 02114 (United States); Baltas, D. [Department of Medical Physics and Engineering, Strahlenklinik, Klinikum Offenbach GmbH, 63069 Offenbach (Germany); Nuclear and Particle Physics Section, Physics Department, University of Athens, 15701 Athens (Greece); Karabis, A. [Pi-Medical Ltd., Athens 10676 (Greece); Mavroidis, P. [Department of Radiological Sciences, University of Texas Health Sciences Center, San Antonio, Texas 78299 and Department of Medical Radiation Physics, Karolinska Institutet and Stockholm University, 17176 (Sweden); Zamboglou, N.; Tselis, N. [Strahlenklinik, Klinikum Offenbach GmbH, 63069 Offenbach (Germany); Shi, C. [St. Vincent' s Medical Center, 2800 Main Street, Bridgeport, Connecticut 06606 (United States); Papanikolaou, N. [Department of Radiological Sciences, University of Texas Health Sciences Center, San Antonio, Texas 78299 (United States)

    2013-04-15

    Purpose: The purpose of this work was to study the feasibility of a new inverse planning technique based on the generalized equivalent uniform dose for image-guided high dose rate (HDR) prostate cancer brachytherapy in comparison to conventional dose-volume based optimization. Methods: The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO (Hybrid Inverse Planning Optimization) is compared with alternative plans, which were produced through inverse planning using the generalized equivalent uniform dose (gEUD). All the common dose-volume indices for the prostate and the organs at risk were considered together with radiobiological measures. The clinical effectiveness of the different dose distributions was investigated by comparing dose volume histogram and gEUD evaluators. Results: Our results demonstrate the feasibility of gEUD-based inverse planning in HDR brachytherapy implants for prostate. A statistically significant decrease in D{sub 10} or/and final gEUD values for the organs at risk (urethra, bladder, and rectum) was found while improving dose homogeneity or dose conformity of the target volume. Conclusions: Following the promising results of gEUD-based optimization in intensity modulated radiation therapy treatment optimization, as reported in the literature, the implementation of a similar model in HDR brachytherapy treatment plan optimization is suggested by this study. The potential of improved sparing of organs at risk was shown for various gEUD-based optimization parameter protocols, which indicates the ability of this method to adapt to the user's preferences.

  18. A Monte Carlo dosimetry study using Henschke applicator for cervical brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Pei-Chieh [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, 101 Sec. 2, Kung Fu Road, Hsinchu 30013, Taiwan (China); Department of Radiation Oncology, Cathay General Hospital, 280 Renai Rd. Sec.4, Taipei 106, Taiwan (China); Chao, Tsi-Chian [Department of Medical Imaging and Radiological Science, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan (China); Lee, Chung-Chi [Department of Medical Imaging and Radiological Science, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, 5 Fu-Hsin Street, Kwei-Shan, Tao-Yuan 333, Taiwan (China); Wu, Ching-Jung [Department of Radiation Oncology, Cathay General Hospital, 280 Renai Rd. Sec.4, Taipei 106, Taiwan (China); Tung, Chuan-Jong, E-mail: cjtung@mail.cgu.edu.t [Department of Medical Imaging and Radiological Science, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan (China)

    2010-07-21

    In recent years the Henschke applicator has been widely used for gynecologic patients treated by brachytherapy in Taiwan. However, the commercial brachytherapy planning system did not properly evaluate the dose perturbation caused by the Henschke applicator. Since the European Society for Therapeutic Radiology and Oncology advised that the effect of source shielding should be incorporated into the brachytherapy planning system, it required calculation and comparison of the dose distribution around the applicator. This study used the Monte Carlo MCNP code to simulate the dose distribution in a water phantom that contained the Henschke applicator with one tandem and two ovoids. Three dwell positions of a high dose rate {sup 192}Ir source were simulated by including and excluding the applicator. The mesh tally option of the MCNP was applied to facilitate the calculation of a large number of tallies in the phantom. The voxel size effect and the charge particle equilibrium were studied by comparing the results calculated with different tally options. The calculated results showed that the brachytherapy planning system overestimated the rectal dose and that the shielding material in the applicator contributed more than 40% to the rectal dose.

  19. A single session of intraluminal brachytherapy in palliation of oesophageal cancer

    NARCIS (Netherlands)

    Jager, J; Langendijk, H; Pannebakker, M; Rijken, J; deJong, J

    1995-01-01

    Between September 1987 and September 1993, 88 patients with oesophageal cancer were treated by a single session of intraluminal brachytherapy of 15 Gy prescribed at 1 cm distance from the central axis, using MDR Cs-137 (n = 51) during the first part of the study and HDR Ir-192 (n = 37) during the se

  20. Dwell time modulation restrictions do not necessarily improve treatment plan quality for prostate HDR brachytherapy

    NARCIS (Netherlands)

    Balvert, M.; Gorissen, B.L.; den Hertog, D.; Hoffmann, A.L.

    2015-01-01

    Inverse planning algorithms for dwell time optimisation in interstitial high-dose-rate (HDR) brachytherapy may produce solutions with large dwell time variations within catheters, which may result in undesirable selective high-dose subvolumes. Extending the dwell time optimisation model with a dwell

  1. HDR Brachytherapy Dose Distribution is Influenced by the Metal Material of the Applicator.

    Science.gov (United States)

    Wu, Chin-Hui; Liao, Yi-Jen; Shiau, An-Cheng; Lin, Hsin-Yu; Hsueh Liu, Yen-Wan; Hsu, Shih-Ming

    2015-12-11

    Applicators containing metal have been widely used in recent years when applying brachytherapy to patients with cervical cancer. However, the high dose rate (HDR) treatment-planning system (TPS) that is currently used in brachytherapy still assumes that the treatment environment constitutes a homogeneous water medium and does not include a dose correction for the metal material of the applicator. The primary purpose of this study was to evaluate the HDR (192)Ir dose distribution in cervical cancer patients when performing brachytherapy using a metal-containing applicator. Thermoluminescent dosimeter (TLD) measurements and Monte Carlo N-Particle eXtended (MCNPX) code were used to explore the doses to the rectum and bladder when using a Henschke applicator containing metal during brachytherapy. When the applicator was assumed to be present, the absolute dose difference between the TLD measurement and MCNPX simulation values was within approximately 5%. A comparison of the MCNPX simulation and TPS calculation values revealed that the TPS overestimated the International Commission of Radiation Units and Measurement (ICRU) rectum and bladder reference doses by 57.78% and 49.59%, respectively. We therefore suggest that the TPS should be modified to account for the shielding effects of the applicator to ensure the accuracy of the delivered doses.

  2. Methodology for commissioning a brachytherapy treatment planning system in the era of 3D planning.

    Science.gov (United States)

    Dempsey, Claire

    2010-12-01

    To describe the steps undertaken to commission a 3D high dose rate (HDR) brachytherapy treatment planning system (TPS). Emphasis was placed on validating previously published recommendations, in addition to checking 3D parameters such as treatment optimization and dose volume histogram (DVH) analysis. Commissioning was performed of the brachytherapy module of the Nucletron Oncentra MasterPlan treatment planning system (version 3.2). Commissioning test results were compared to an independent external beam TPS (Varian Eclipse v 8.6) and the previously commissioned Nucletron Plato (v 14.3.7) brachytherapy treatment planning system, with point doses also independently verified using the brachytherapy module in RadCalc (v 6.0) independent point dose calculation software. Tests were divided into eight categories: (i) Image import accuracy, (ii) Reconstruction accuracy, (iii) Source configuration data check, (iv) Dose calculation accuracy, (v) Treatment optimization validation, (vi) DVH reproducibility, (vii) Treatment export check and (viii) Printout consistency. Point dose agreement between Oncentra, Plato and RadCalc was better than 5% with source data and dose calculation protocols following the American Association of Physicists in Medicine (AAPM) guidelines. Testing of image accuracy (import and reconstruction), along with validation of automated treatment optimization and DVH analysis generated a more comprehensive set of testing procedures than previously listed in published recommendations.

  3. The role of interstitial brachytherapy in the management of primary radiation therapy for uterine cervical cancer

    Directory of Open Access Journals (Sweden)

    Naoya Murakami

    2016-10-01

    Full Text Available Purpose : The aim of this study was to report the clinical results of uterine cervical cancer patients treated by primary radiation therapy including brachytherapy, and investigate the role of interstitial brachytherapy (ISBT. Material and methods: All consecutive uterine cervical cancer patients who were treated by primary radiation therapy were reviewed, and those who were treated by ISBT were further investigated for clinical outcomes and related toxicities. Results : From December 2008 to October 2014, 209 consecutive uterine cervical cancer patients were treated with primary radiation therapy. Among them, 142 and 42 patients were treated by intracavitary and hybrid brachytherapy, respectively. Twenty-five patients (12% were treated by high-dose-rate (HDR-ISBT. Five patients with distant metastasis other than para-aortic lymph node were excluded, and 20 patients consisted of the analysis. Three-year overall survival (OS, progression-free survival (PFS, and local control (LC rate were 44.4%, 38.9%, and 87.8%, respectively. Distant metastasis was the most frequent site of first relapse after HDR-ISBT. One and four patients experienced grade 3 and 2 rectal bleeding, one grade 2 cystitis, and two grade 2 vaginal ulcer. Conclusions : Feasibility and favorable local control of interstitial brachytherapy for locally advanced cervical cancer was demonstrated through a single institutional experience with a small number of patients.

  4. Salvage/Adjuvant Brachytherapy After Ophthalmic Artery Chemosurgery for Intraocular Retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Francis, Jasmine H., E-mail: francij1@mskcc.org [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Barker, Christopher A.; Wolden, Suzanne L.; McCormick, Beryl; Segal, Kira; Cohen, Gil [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Gobin, Y. Pierre; Marr, Brian P. [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Weill-Cornell Medical College, New York-Presbyterian Hospital, New York, New York (United States); Brodie, Scott E. [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Mount Sinai School of Medicine, New York, New York (United States); Dunkel, Ira J.; Abramson, David H. [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Weill-Cornell Medical College, New York-Presbyterian Hospital, New York, New York (United States)

    2013-11-01

    Purpose: To evaluate the efficacy and toxicity of brachytherapy after ophthalmic artery chemosurgery (OAC) for retinoblastoma. Methods and Materials: This was a single-arm, retrospective study of 15 eyes in 15 patients treated with OAC followed by brachytherapy at (blinded institution) between May 1, 2006, and December 31, 2012, with a median 19 months' follow-up from plaque insertion. Outcome measurements included patient and ocular survival, visual function, and retinal toxicity measured by electroretinogram (ERG). Results: Brachytherapy was used as adjuvant treatment in 2 eyes and as salvage therapy in 13 eyes of which 12 had localized vitreous seeding. No patients developed metastasis or died of retinoblastoma. The Kaplan-Meier estimate of ocular survival was 79.4% (95% confidence interval 48.7%-92.8%) at 18 months. Three eyes were enucleated, and an additional 6 eyes developed out-of-target volume recurrences, which were controlled with additional treatments. Patients with an ocular complication had a mean interval between last OAC and plaque of 2.5 months (SD 2.3 months), which was statistically less (P=.045) than patients without ocular complication who had a mean interval between last OAC and plaque of 6.5 months (SD 4.4 months). ERG responses from pre- versus postplaque were unchanged or improved in more than half the eyes. Conclusions: Brachytherapy following OAC is effective, even in the presence of vitreous seeding; the majority of eyes maintained stable or improved retinal function following treatment, as assessed by ERG.

  5. Long-term outcomes of eye-conserving treatment with Ruthenium(106) brachytherapy for choroidal melanoma.

    NARCIS (Netherlands)

    Verschueren, K.M.; Creutzberg, C.L.; Schalij-Delfos, N.E.; Ketelaars, M.; Klijsen, F.L.; Haeseker, B.I.; Ligtenberg, S.M.; Keunen, J.E.E.; Marijnen, C.A.

    2010-01-01

    PURPOSE: To evaluate long-term outcomes of eye-conserving treatment using Ruthenium-106 plaque brachytherapy with or without transpupillary thermotherapy (TTT) for small to intermediate size choroidal melanomas. METHODS: Outcomes of 425 consecutive patients were analysed. The median basal tumour

  6. Dosimetric comparison of MRI-based HDR brachytherapy and stereotactic radiotherapy in patients with advanced cervical cancer: A virtual brachytherapy study

    Science.gov (United States)

    Otahal, Bretislav; Dolezel, Martin; Cvek, Jakub; Simetka, Ondrej; Klat, Jaroslav; Knybel, Lukas; Molenda, Lukas; Skacelikova, Eva; Hlavka, Ales; Feltl, David

    2014-01-01

    Aim To evaluate the treatment plans of 3D image-guided brachytherapy (BT) and stereotactic robotic radiotherapy with online image guidance – CyberKnife (CK) in patients with locally advanced cervix cancer. Methods and materials Ten pairs of plans for patients with locally advanced inoperable cervical cancer were created using MR based 3D brachytherapy and stereotaxis CK. The dose that covers 98% of the target volume (HR CTV D98) was taken as a reference and other parameters were compared. Results Of the ten studied cases, the dose from D100 GTV was comparable for both devices, on average, the BT GTV D90 was 10–20% higher than for CK. The HR CTV D90 was higher for CK with an average difference of 10–20%, but only fifteen percent of HR CTV (the peripheral part) received a higher dose from CK, while 85% of the target volume received higher doses from BT. We found a significant organ-sparing effect of CK compared to brachytherapy (20–30% lower doses in 0.1 cm3, 1 cm3, and 2 cm3). Conclusion BT remains to be the best method for dose escalation. Due to the significant organ-sparing effect of CK, patients that are not candidates for BT could benefit from stereotaxis more than from classical external beam radiotherapy. PMID:25337413

  7. Brachytherapy on restenosis. {sup 32}P radioisotope in animal model

    Energy Technology Data Exchange (ETDEWEB)

    Bergoc, R.; Rivera, E.; Cocca, C.; Martin, G.; Cricco, G. [Buenos Aires Univ. (Argentina). School of Pharmacy and Biochemistry; Croci, M.; Guzman, L.

    2000-05-01

    Despite a notorious decline in age-adjusted death rates for cardiovascular pathologies, coronary artery disease still remains as the main cause of mortality above the age of 40 in men and 60 in women. More than 25% of death in persons over the age of 35 are due to coronary disease. In about 50% of men and 30% of women, the first manifestation of the disease is an acute myocardial infarction and 10% a sudden cardiac death. In Argentina it is estimated that in 1998 about 100.000-115.000 people suffered as first manifestation of coronary illness a myocardial acute infarct. Angioplasty has an important and well established site in the treatment of the coronary illness and restenosis represents the principal complication of this method for myocardial re-vascularization. About a 35-40% of treated arteries present restenosis within the first six month the intervention with the concomitant need of re-interventions, re-hospitalizations, by-pass surgery, work discontinuity and the high cost for the health system. A number of drugs were tested as anti-restenosis: anticoagulants, aspirin, antispasmodics and lipid-lowering agents but none was clearly efficient; also, experimental studies in which intravascular irradiation with different source types and energies, radiation doses and doses rate to prevent restenosis was utilized; however, there is no consensus in many aspects of this intravascular brachytherapy. The first step in this work was to induce the experimental model in rabbits. Afterwards, by means of the balloon methodology and stent implantation, brachytherapy experiments were carried out to evaluate the biological effect on different layers of arteries, with different Doses using a beta particle emitting radioisotope ({sup 32}P). The arteriosclerotic lesions were induced in New Zealand rabbits through the administration of a diet with high cholesterol content. Angioplastic interventions on femoral arteries were done with balloon methodology and controlled by

  8. Stereotactic interstitial brachytherapy for the treatment of oligodendroglial brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    El Majdoub, Faycal; Neudorfer, Clemens; Maarouf, Mohammad [University Hospital of Cologne, Department of Stereotaxy and Functional Neurosurgery, Cologne (Germany); University of Witten/Herdecke, Department of Stereotaxy and Functional Neurosurgery, Center of Neurosurgery, Cologne-Merheim Medical Center (CMMC), Cologne (Germany); Blau, Tobias; Deckert, Martina [University Hospital of Cologne, Department of Neuropathology, Cologne (Germany); Hellmich, Martin [University Hospital of Cologne, Institute of Statistics, Informatics and Epidemiology, Cologne (Germany); Buehrle, Christian [University Hospital of Cologne, Department of Stereotaxy and Functional Neurosurgery, Cologne (Germany); Sturm, Volker [University Hospital of Cologne, Department of Stereotaxy and Functional Neurosurgery, Cologne (Germany); University Hospital of Wurzburg, Department of Neurosurgery, Wuerzburg (Germany)

    2015-12-15

    We evaluated the treatment of oligodendroglial brain tumors with interstitial brachytherapy (IBT) using {sup 125}iodine seeds ({sup 125}I) and analyzed prognostic factors. Between January 1991 and December 2010, 63 patients (median age 43.3 years, range 20.8-63.4 years) suffering from oligodendroglial brain tumors were treated with {sup 125}I IBT either as primary, adjuvantly after incomplete resection, or as salvage therapy after tumor recurrence. Possible prognostic factors influencing disease progression and survival were retrospectively investigated. The actuarial 2-, 5-, and 10-year overall and progression-free survival rates after IBT for WHO II tumors were 96.9, 96.9, 89.8 % and 96.9, 93.8, 47.3 %; for WHO III tumors 90.3, 77, 54.9 % and 80.6, 58.4, 45.9 %, respectively. Magnetic resonance imaging demonstrated complete remission in 2 patients, partial remission in 13 patients, stable disease in 17 patients and tumor progression in 31 patients. Median time to progression for WHO II tumors was 87.6 months and for WHO III tumors 27.8 months. Neurological status improved in 10 patients and remained stable in 20 patients, while 9 patients deteriorated. There was no treatment-related mortality. Treatment-related morbidity was transient in 11 patients. WHO II, KPS ≥ 90 %, frontal location, and tumor surface dose > 50 Gy were associated with increased overall survival (p ≤ 0.05). Oligodendroglioma and frontal location were associated with a prolonged progression-free survival (p ≤ 0.05). Our study indicates that IBT achieves local control rates comparable to surgery and radio-/chemotherapy treatment, is minimally invasive, and safe. Due to the low rate of side effects, IBT may represent an attractive option as part of a multimodal treatment schedule, being supplementary to microsurgery or as a salvage therapy after chemotherapy and conventional irradiation. (orig.) [German] Die Behandlung oligodendroglialer Hirntumoren durch die interstitielle Brachytherapie

  9. Brachytherapy Application With In Situ Dose Painting Administered by Gold Nanoparticle Eluters

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Neeharika [Department of Sciences, Wentworth Institute of Technology, Boston, Massachusetts (United States); Cifter, Gizem [Department of Physics and Applied Physics, University of Massachusetts, Lowell, Massachusetts (United States); Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts (United States); Sajo, Erno [Department of Physics and Applied Physics, University of Massachusetts, Lowell, Massachusetts (United States); Kumar, Rajiv; Sridhar, Srinivas [Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts (United States); Electronic Materials Research Institute and Department of Physics, Northeastern University, Boston, Massachusetts (United States); Nguyen, Paul L.; Cormack, Robert A.; Makrigiorgos, G. Mike [Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts (United States); Ngwa, Wilfred, E-mail: wngwa@lroc.harvard.edu [Department of Physics and Applied Physics, University of Massachusetts, Lowell, Massachusetts (United States); Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts (United States)

    2015-02-01

    Purpose: Recent studies show promise that administering gold nanoparticles (GNP) to tumor cells during brachytherapy could significantly enhance radiation damage to the tumor. A new strategy proposed for sustained administration of the GNP in prostate tumors is to load them into routinely used brachytherapy spacers for customizable in situ release after implantation. This in silico study investigated the intratumor biodistribution and corresponding dose enhancement over time due to GNP released from such GNP-loaded brachytherapy spacers (GBS). Method and Materials: An experimentally determined intratumoral diffusion coefficient (D) for 10-nm nanoparticles was used to estimate D for other sizes by using the Stokes-Einstein equation. GNP concentration profiles, obtained using D, were then used to calculate the corresponding dose enhancement factor (DEF) for each tumor voxel, using dose painting-by-numbers approach, for times relevant to the considered brachytherapy sources' lifetimes. The investigation was carried out as a function of GNP size for the clinically applicable low-dose-rate brachytherapy sources iodine-125 (I-125), palladium-103 (Pd-103), and cesium-131 (Cs-131). Results: Results showed that dose enhancement to tumor voxels and subvolumes during brachytherapy can be customized by varying the size of GNP released or eluted from the GBS. For example, using a concentration of 7 mg/g GNP, significant DEF (>20%) could be achieved 5 mm from a GBS after 5, 12, 25, 46, 72, 120, and 195 days, respectively, for GNP sizes of 2, 5, 10, 20, 30, and 50 nm and for 80 nm when treating with I-125. Conclusions: Analyses showed that using Cs-131 provides the highest dose enhancement to tumor voxels. However, given its relatively longer half-life, I-125 presents the most flexibility for customizing the dose enhancement as a function of GNP size. These findings provide a useful reference for further work toward development of potential new brachytherapy application

  10. Localization of brachytherapy seeds in ultrasound by registration to fluoroscopy

    Science.gov (United States)

    Fallavollita, P.; KarimAghaloo, Z.; Burdette, E. C.; Song, D. Y.; Abolmaesumi, P.; Fichtinger, G.

    2010-02-01

    Motivation: In prostate brachytherapy, transrectal ultrasound (TRUS) is used to visualize the anatomy, while implanted seeds can be seen in C-arm fluoroscopy or CT. Intra-operative dosimetry optimization requires localization of the implants in TRUS relative to the anatomy. This could be achieved by registration of TRUS images and the implants reconstructed from fluoroscopy or CT. Methods: TRUS images are filtered, compounded, and registered on the reconstructed implants by using an intensity-based metric based on a 3D point-to-volume registration scheme. A phantom was implanted with 48 seeds, imaged with TRUS and CT/X-ray. Ground-truth registration was established between the two. Seeds were reconstructed from CT/X-ray. Seven TRUS filtering techniques and two image similarity metrics were analyzed as well. Results: For point-to-volume registration, noise reduction combined with beam profile filter and mean squares metrics yielded the best result: an average of 0.38 +/- 0.19 mm seed localization error relative to the ground-truth. In human patient data C-arm fluoroscopy images showed 81 radioactive seeds implanted inside the prostate. A qualitative analysis showed clinically correct agreement between the seeds visible in TRUS and reconstructed from intra-operative fluoroscopy imaging. The measured registration error compared to the manually selected seed locations by the clinician was 2.86 +/- 1.26 mm. Conclusion: Fully automated seed localization in TRUS performed excellently on ground-truth phantom, adequate in clinical data and was time efficient having an average runtime of 90 seconds.

  11. Techniques and results of brachytherapy for carcinoma of the tongue

    Energy Technology Data Exchange (ETDEWEB)

    Jingu, Kenichi; Akita, Yuzou [Fukuoka Univ. (Japan). School of Medicine; Shimamura, Yasushi; Kunitake, Naonobu; Nakamura, Kazumasa; Oomagari, Junichi; Wada, Susumu; Uehara, Satoru; Masuda, Kouji

    1997-11-01

    Three hundred and twelve patients with 1987 UICC T1, 2 carcinoma of the tongue, who underwent definitive brachytherapy from November, 1978 to March, 1991 in the Department of Radiology, Kyushu University Hospital, and from January, 1985 to December, 1994 in the Department of Radiotherapy, Kyushu Cancer Center, were reviewed retrospectively. All patients were admitted 15-30 mg Pentazocine and O.25 mg Atropine sulfate as the premedication. Thirty to 60 minutes after, the tip of tongue and the lesion were put under local infiltration anesthesia with 10-20 ml of 1-2% Lidocaine or 1% Procaine HCL. The tongue was pulled out by the thread of the tip. Partial resection or wide excisional biopsy of the tumor was performed to reduce the tumor volume and the radiation volume and also to estimate Jacobson-Yamamoto`s grading histologically in the bottom of the tumor. Radium needles or Iridium hair pins were implanted in the lesion following Paterson`s method, and left for 3-10 days to the minimum tumor dose of 70 Gy calculated by computer. The secondary neck lymph node metastases rates of the patients with T1 carcinoma of the tongue were 27% and 53% in the Jacobson-Yamamoto grading 1-3 group and 4 group. The rates of the patients with T2 were 28% and 82% in 1-3 group and 4 group. Two year`s local control rates of the patients with T1 and T2 carcinoma were 95% and 82%. Two year`s late reaction (mandibular bone exposure or refractory ulcer of soft tissue) rates of the patients with T1 and T2 carcinoma were 7% and 12%. (author)

  12. Minimal percentage of dose received by 90% of the urethra (%UD90 is the most significant predictor of PSA bounce in patients who underwent low-dose-rate brachytherapy (LDR-brachytherapy for prostate cancer

    Directory of Open Access Journals (Sweden)

    Tanaka Nobumichi

    2012-09-01

    Full Text Available Abstract Background To clarify the significant clinicopathological and postdosimetric parameters to predict PSA bounce in patients who underwent low-dose-rate brachytherapy (LDR-brachytherapy for prostate cancer. Methods We studied 200 consecutive patients who received LDR-brachytherapy between July 2004 and November 2008. Of them, 137 patients did not receive neoadjuvant or adjuvant androgen deprivation therapy. One hundred and forty-two patients were treated with LDR-brachytherapy alone, and 58 were treated with LDR-brachytherapy in combination with external beam radiation therapy. The cut-off value of PSA bounce was 0.1 ng/mL. The incidence, time, height, and duration of PSA bounce were investigated. Clinicopathological and postdosimetric parameters were evaluated to elucidate independent factors to predict PSA bounce in hormone-naïve patients who underwent LDR-brachytherapy alone. Results Fifty patients (25% showed PSA bounce and 10 patients (5% showed PSA failure. The median time, height, and duration of PSA bounce were 17 months, 0.29 ng/mL, and 7.0 months, respectively. In 103 hormone-naïve patients treated with LDR-brachytherapy alone, and univariate Cox proportional regression hazard model indicated that age and minimal percentage of the dose received by 30% and 90% of the urethra were independent predictors of PSA bounce. With a multivariate Cox proportional regression hazard model, minimal percentage of the dose received by 90% of the urethra was the most significant parameter of PSA bounce. Conclusions Minimal percentage of the dose received by 90% of the urethra was the most significant predictor of PSA bounce in hormone-naïve patients treated with LDR-brachytherapy alone.

  13. EM-navigated catheter placement for gynecologic brachytherapy: an accuracy study

    Science.gov (United States)

    Mehrtash, Alireza; Damato, Antonio; Pernelle, Guillaume; Barber, Lauren; Farhat, Nabgha; Viswanathan, Akila; Cormack, Robert; Kapur, Tina

    2014-03-01

    Gynecologic malignancies, including cervical, endometrial, ovarian, vaginal and vulvar cancers, cause significant mortality in women worldwide. The standard care for many primary and recurrent gynecologic cancers consists of chemoradiation followed by brachytherapy. In high dose rate (HDR) brachytherapy, intracavitary applicators and /or interstitial needles are placed directly inside the cancerous tissue so as to provide catheters to deliver high doses of radiation. Although technology for the navigation of catheters and needles is well developed for procedures such as prostate biopsy, brain biopsy, and cardiac ablation, it is notably lacking for gynecologic HDR brachytherapy. Using a benchtop study that closely mimics the clinical interstitial gynecologic brachytherapy procedure, we developed a method for evaluating the accuracy of image-guided catheter placement. Future bedside translation of this technology offers the potential benefit of maximizing tumor coverage during catheter placement while avoiding damage to the adjacent organs, for example bladder, rectum and bowel. In the study, two independent experiments were performed on a phantom model to evaluate the targeting accuracy of an electromagnetic (EM) tracking system. The procedure was carried out using a laptop computer (2.1GHz Intel Core i7 computer, 8GB RAM, Windows 7 64-bit), an EM Aurora tracking system with a 1.3mm diameter 6 DOF sensor, and 6F (2 mm) brachytherapy catheters inserted through a Syed-Neblett applicator. The 3D Slicer and PLUS open source software were used to develop the system. The mean of the targeting error was less than 2.9mm, which is comparable to the targeting errors in commercial clinical navigation systems.

  14. High dose rate interstitial brachytherapy in soft tissue sarcomas: technical aspect

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Mi Son; Kang, Seung Hee; Kim, Byoung Suck; Oh, Young Taek [College of Medicine, Ajou Univ., Suwon (Korea, Republic of)

    1999-03-01

    To discuss the technical aspect of interstitial brachytherapy including method of implant, insertion time of radioactive source, total radiation dose, and complication, we reviewed patients who had diagnoses of soft tissue sarcoma and were treated by conservative surgery, interstitial implant and external beam radiation therapy. Between May 1995 and Dec. 1997, the patients with primary or recurrent soft tissue sarcoma underwent surgical resection (wide margin excision) and received radiotherapy including interstitial brachytherapy. Catheters were placed with regular intervals of 1-1.5 cm immediately after tumor removal and covering the critical structures, such as neurovascular bundle or bone, with gelform, muscle, or tissue expander in the cases where the tumors were close to those structures. Brachytherapy consisted of source axis with 2-2.5 Gy/fraction, twice a day, starting on 6th day after the surgery. Within one month after the surgery, total dose of 50-55 Gy was delivered to the tumor bed with wide margin by the external beam radiotherapy. All patients completed planned interstitial brachytherapy without acute side effects directly related with catheter implantation such as infection or bleeding. With median follow up duration of 25 months (range 12-41 months), no local recurrences were observed. And there was no severe form of chromic complication (RTOG/EORTC grade 3 or 4). The high dose rate interstitial brachytherapy is easy and safe way to minimize the radiation dose delivered to the adjacent normal tissue and to decrease radiation induced chronic morbidity such as fibrosis by reducing the total dose of external radiotherapy in the management of soft tissue sarcoma with conservative surgery.

  15. On the Development of a Miniature Neutron Generator for the Brachytherapy Treatment of Cancer

    Science.gov (United States)

    Forman, L.

    2009-03-01

    Brachytherapy refers to application of an irradiation source within a tumor. 252Cf needles used in brachytherapy have been successfully applied to treatment of some of the most virulent cancers but it is doubtful that it will be widely used because of difficulty in dealing with unwanted dose (source cannot be turned off) and in adhering to stringent NRC regulations that have been exacerbated in our post 911 environment. We have been working on the development of a miniature neutron generator with the reaction target placed at the end of a needle (tube) for brachytherapy applications. Orifice geometries are most amenable, e.g. rectum and cervix, but interstitial use is possible with microsurgery. This paper dicusses the results of a 30 watt DD neutron generator SBU project that demonstrates that sufficient hydrogen isotope current can be delivered down a small diameter needle required for a DT neutron treatment device, and, will summarize the progress of building a commercial device pursued by the All Russian Institute for Automatics (VNIIA) supported by the DOE's Industrial Proliferation Prevention Program (IPP). It is known that most of the fast neutron (FN) beam cancer treatment facilities have been closed down. It appears that the major limitation in the use of FN beams has been damage to healthy tissue, which is relatively insensitive to photons, but this problem is alleviated by brachytherapy. Moreover, recent clinical results indicate that fast neutrons in the boost mode are most highly effective in treating large, hypoxic, and rapidly repopulating diseases. It appears that early boost application of FN may halt angiogenesis (development and repair of tumor vascular system) and shrink the tumor resulting in lower hypoxia. The boost brachytherapy application of a small, low cost neutron generator holds promise of significant contribution to the treatment of cancer.

  16. High dose rate endobronchial brachytherapy. Results and complications in 189 patients

    Energy Technology Data Exchange (ETDEWEB)

    Taulelle, M.; Chauvet, B.; Vincent, P.; Felix-Faure, C.; Buciarelli, B.; Garcia, R.; Brewer, Y.; Reboul, F. [Clinique Sainte Catherine, Dept. of Radiation Therapy, Avignon (France)

    1998-02-01

    The purpose of this study was to determine the benefit of high dose rate endobronchial brachytherapy in the treatment of obstructive lung cancer. Between September 1990 and March 1995, 189 patients with bronchogenic carcinoma were treated with high dose rate endobronchial brachytherapy. Most patients (63.3%) had received prior treatment and presented with symptomatic bronchial obstruction due to either recurrent or residual endobronchial disease. A small group (12%) was medically unfit for either surgical resection or thoracic radiotherapy and benefited from endobronchial brachytherapy alone for small endobronchial tumours. The remainder of the patients had not been treated previously and endobronchial brachytherapy was performed for life-threatening symptoms requiring emergency obstruction relief before other therapy. Treatment was performed weekly and consisted of three to four 8 to 10 Gy fractions at a radius of 10 mm from the centre of the source. Major symptomatic relief was obtained for haemoptysis (74%), dyspnoea (54%), and cough (54%). Complete endoscopic response was observed in 54% of cases. Median survival was 7 months for the entire group. For small, strictly endobronchial tumours, complete response rate was 96%, median survival 17 months, and 30 month survival 46%, with a plateau starting at 18 months. Grade 3 to 4 toxicities occurred at a rate of 17% and included massive haemoptysis (n=13), bronchial stenosis (n=12), soft tissue necrosis (n=8), and bronchial fistula (n=3). By univariate analysis, no factor was found to be predictive of late pulmonary toxicity. The present study confirms the usefulness of endobronchial brachytherapy in alleviating symptoms caused by endobronchial recurrence of bronchogenic carcinoma. In addition, this therapy can be tried with curative intent in patients who present with small endobronchial tumours and are not candidates for other forms of therapy. (au). 23 refs.

  17. Evaluation of EGS4/PRESTA multiple-scattering algorithms for 90Sr/90Y intravascular brachytherapy dosimetry.

    Science.gov (United States)

    Wang, R; Li, X A; Yu, C X

    2000-08-01

    The purpose of this work is to evaluate the EGS4/PRESTA electron multiple-scattering (MS) algorithms for dose calculation in intravascular brachytherapy (IVBT) using a 90Sr/90Y source. The small source size and the small volume of interest in IVBT require very fine spatial resolution, which may break down the constraints of Molière's MS theory as implemented in EGS4. The theory is accurate only when the electron step sizes are large enough to allow the number of collisions omega0 to be much greater than e = 2.7183. When step sizes are too small to allow at least 2.7183 collisions, as may be necessitated by the fine geometry, the algorithm may switch off MS, producing dosimetric artefacts. This study showed that switching off MS could produce a dose deviation of up to 6% when the half-thickness (d/2) of the dose scoring region is comparable with the Moliere minimum step size (t(min) = 2.7183). The effect of switching off MS is negligible if d/2 > t(min) For the case of omega0 > e, if the electron step sizes are chosen to allow five to 40 collisions, with increasing step size, the doses surrounding the source increase and the error decreases. On the other hand, when larger step sizes are chosen, the dose calculation voxel size must also be increased in order for the calculations to converge. A good compromise between accuracy and applicability for IVBT simulation can be made, if the thickness of the scoring region is 0.1 mm and the electron step sizes are in the range allowing 10 to 30 collisions.

  18. Treatment planning for multicatheter interstitial brachytherapy of breast cancer - from Paris system to anatomy-based inverse planning

    National Research Council Canada - National Science Library

    Tibor Major; Csaba Polgár

    2017-01-01

    .... The catheter reconstruction is also easier and faster on CT images compared to X-ray films. In high dose rate brachytherapy, using a stepping source, a number of forward dose optimization methods...

  19. Development of an open source software module for enhanced visualization during MR-guided interstitial gynecologic brachytherapy.

    Science.gov (United States)

    Chen, Xiaojun; Egger, Jan

    2014-01-01

    In 2010, gynecologic malignancies were the 4th leading cause of death in U.S. women and for patients with extensive primary or recurrent disease, treatment with interstitial brachytherapy may be an option. However, brachytherapy requires precise insertion of hollow catheters with introducers into the tumor in order to eradicate the cancer. In this study, a software solution to assist interstitial gynecologic brachytherapy has been investigated and the software has been realized as an own module under (3D) Slicer, which is a free open source software platform for (translational) biomedical research. The developed research module allows on-time processing of intra-operative magnetic resonance imaging (iMRI) data over a direct DICOM connection to a MR scanner. Afterwards follows a multi-stage registration of CAD models of the medical brachytherapy devices (template, obturator) to the patient's MR images, enabling the virtual placement of interstitial needles to assist the physician during the intervention.

  20. Brachytherapy for Patients With Prostate Cancer: American Society of Clinical Oncology/Cancer Care Ontario Joint Guideline Update.

    Science.gov (United States)

    Chin, Joseph; Rumble, R Bryan; Kollmeier, Marisa; Heath, Elisabeth; Efstathiou, Jason; Dorff, Tanya; Berman, Barry; Feifer, Andrew; Jacques, Arthur; Loblaw, D Andrew

    2017-03-27

    Purpose To jointly update the Cancer Care Ontario guideline on brachytherapy for patients with prostate cancer to account for new evidence. Methods An Update Panel conducted a targeted systematic literature review and identified more recent randomized controlled trials comparing dose-escalated external beam radiation therapy (EBRT) with brachytherapy in men with prostate cancer. Results Five randomized controlled trials provided the evidence for this update. Recommendations For patients with low-risk prostate cancer who require or choose active treatment, low-dose rate brachytherapy (LDR) alone, EBRT alone, and/or radical prostatectomy (RP) should be offered to eligible patients. For patients with intermediate-risk prostate cancer choosing EBRT with or without androgen-deprivation therapy, brachytherapy boost (LDR or high-dose rate [HDR]) should be offered to eligible patients. For low-intermediate risk prostate cancer (Gleason 7, prostate-specific antigen < 10 ng/mL or Gleason 6, prostate-specific antigen, 10 to 20 ng/mL), LDR brachytherapy alone may be offered as monotherapy. For patients with high-risk prostate cancer receiving EBRT and androgen-deprivation therapy, brachytherapy boost (LDR or HDR) should be offered to eligible patients. Iodine-125 and palladium-103 are each reasonable isotope options for patients receiving LDR brachytherapy; no recommendation can be made for or against using cesium-131 or HDR monotherapy. Patients should be encouraged to participate in clinical trials to test novel or targeted approaches to this disease. Additional information is available at www.asco.org/Brachytherapy-guideline and www.asco.org/guidelineswiki .

  1. High Intensity Focused Ultrasound versus Brachytherapy for the Treatment of Localized Prostate Cancer: A Matched-Pair Analysis

    Directory of Open Access Journals (Sweden)

    Fouad Aoun

    2015-01-01

    Full Text Available Purpose. To evaluate postoperative morbidity and long term oncologic and functional outcomes of high intensity focused ultrasound (HIFU compared to brachytherapy for the treatment of localized prostate cancer. Material and Methods. Patients treated by brachytherapy were matched 1 : 1 with patients who underwent HIFU. Differences in postoperative complications across the two groups were assessed using Wilcoxon’s rank-sum or χ2 test. Kaplan-Meier curves, log-rank tests, and Cox regression models were constructed to assess differences in survival rates between the two groups. Results. Brachytherapy was significantly associated with lower voiding LUTS and less frequent acute urinary retention (p<0.05. Median oncologic follow-up was 83 months (13–123 months in the HIFU cohort and 44 months (13–89 months in the brachytherapy cohort. Median time to achieve PSA nadir was statistically shorter in the HIFU. Biochemical recurrence-free survival rate was significantly higher in the brachytherapy cohort compared to HIFU cohort (68.5% versus 53%, p<0.05. No statistically significant difference in metastasis-free, cancer specific, and overall survivals was observed between the two groups. Conclusion. HIFU and brachytherapy are safe with no significant difference in cancer specific survival on long term oncologic follow-up. Nonetheless, a randomized controlled trial is needed to confirm these results.

  2. Technical Note: Contrast solution density and cross section errors in inhomogeneity-corrected dose calculation for breast balloon brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Leonard H.; Zhang Miao; Howell, Roger W.; Yue, Ning J.; Khan, Atif J. [Department of Radiation Oncology, University of Medicine and Dentistry of New Jersey: Robert Wood Johnson Medical School and Cancer Institute of New Jersey, New Brunswick, New Jersey 08903 (United States); Department of Radiology, University of Medicine and Dentistry of New Jersey: New Jersey Medical School, Newark, New Jersey 07103 (United States); Department of Radiation Oncology, University of Medicine and Dentistry of New Jersey: Robert Wood Johnson Medical School and Cancer Institute of New Jersey, New Brunswick, New Jersey 08903 (United States)

    2013-01-15

    Purpose: Recent recommendations by the American Association of Physicists in Medicine Task Group 186 emphasize the importance of understanding material properties and their effect on inhomogeneity-corrected dose calculation for brachytherapy. Radiographic contrast is normally injected into breast brachytherapy balloons. In this study, the authors independently estimate properties of contrast solution that were expected to be incorrectly specified in a commercial brachytherapy dose calculation algorithm. Methods: The mass density and atomic weight fractions of a clinical formulation of radiographic contrast solution were determined using manufacturers' data. The mass density was verified through measurement and compared with the density obtained by the treatment planning system's CT calibration. The atomic weight fractions were used to determine the photon interaction cross section of the contrast solution for a commercial high-dose-rate (HDR) brachytherapy source and compared with that of muscle. Results: The density of contrast solution was 10% less than that obtained from the CT calibration. The cross section of the contrast solution for the HDR source was 1.2% greater than that of muscle. Both errors could be addressed by overriding the density of the contrast solution in the treatment planning system. Conclusions: The authors estimate the error in mass density and cross section parameters used by a commercial brachytherapy dose calculation algorithm for radiographic contrast used in a clinical breast brachytherapy practice. This approach is adaptable to other clinics seeking to evaluate dose calculation errors and determine appropriate density override values if desired.

  3. Comparison and uncertainty evaluation of different calibration protocols and ionization chambers for low-energy surface brachytherapy dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Candela-Juan, C., E-mail: ccanjuan@gmail.com [Radiation Oncology Department, La Fe University and Polytechnic Hospital, Valencia 46026 (Spain); Vijande, J. [Department of Atomic, Molecular, and Nuclear Physics, University of Valencia, Burjassot 46100, Spain and Instituto de Física Corpuscular (UV-CSIC), Paterna 46980 (Spain); García-Martínez, T. [Radiation Oncology Department, Hospital La Ribera, Alzira 46600 (Spain); Niatsetski, Y.; Nauta, G.; Schuurman, J. [Elekta Brachytherapy, Veenendaal 3905 TH (Netherlands); Ouhib, Z. [Radiation Oncology Department, Lynn Regional Cancer Center, Boca Raton Community Hospital, Boca Raton, Florida 33486 (United States); Ballester, F. [Department of Atomic, Molecular, and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Perez-Calatayud, J. [Radiation Oncology Department, La Fe University and Polytechnic Hospital, Valencia 46026, Spain and Department of Radiotherapy, Clínica Benidorm, Benidorm 03501 (Spain)

    2015-08-15

    Purpose: A surface electronic brachytherapy (EBT) device is in fact an x-ray source collimated with specific applicators. Low-energy (<100 kVp) x-ray beam dosimetry faces several challenges that need to be addressed. A number of calibration protocols have been published for x-ray beam dosimetry. The media in which measurements are performed are the fundamental difference between them. The aim of this study was to evaluate the surface dose rate of a low-energy x-ray source with small field applicators using different calibration standards and different small-volume ionization chambers, comparing the values and uncertainties of each methodology. Methods: The surface dose rate of the EBT unit Esteya (Elekta Brachytherapy, The Netherlands), a 69.5 kVp x-ray source with applicators of 10, 15, 20, 25, and 30 mm diameter, was evaluated using the AAPM TG-61 (based on air kerma) and International Atomic Energy Agency (IAEA) TRS-398 (based on absorbed dose to water) dosimetry protocols for low-energy photon beams. A plane parallel T34013 ionization chamber (PTW Freiburg, Germany) calibrated in terms of both absorbed dose to water and air kerma was used to compare the two dosimetry protocols. Another PTW chamber of the same model was used to evaluate the reproducibility between these chambers. Measurements were also performed with two different Exradin A20 (Standard Imaging, Inc., Middleton, WI) chambers calibrated in terms of air kerma. Results: Differences between surface dose rates measured in air and in water using the T34013 chamber range from 1.6% to 3.3%. No field size dependence has been observed. Differences are below 3.7% when measurements with the A20 and the T34013 chambers calibrated in air are compared. Estimated uncertainty (with coverage factor k = 1) for the T34013 chamber calibrated in water is 2.2%–2.4%, whereas it increases to 2.5% and 2.7% for the A20 and T34013 chambers calibrated in air, respectively. The output factors, measured with the PTW chambers

  4. Obtention of brachytherapy seeds by sealing process using polymer; Obtencao de sementes de braquiterapia pelo processo de selagem com polimero

    Energy Technology Data Exchange (ETDEWEB)

    Lana, Diogo Alberto P.D.; Ferraz, Wilmar B.; Santos, Ana Maria M., E-mail: amms@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Carvalho, Luiz Claudio F.M. Garcia [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2012-08-15

    Brachytherapy is an advanced cancer treatment where radioactive seeds or sources are placed near or directly into the tumor thus reducing the radiation exposure in the surrounding healthy tissues. Several kinds of seeds have been developed in order to obtain a better dose distribution around them and with a lower cost manufacturing. These seeds consist of an encapsulation (titanium or stainless steel tube), a radionuclide carrier, and X-ray marker. The usual sealing process of the seeds is done with laser welding, but this process can promote radionuclide volatilization. In this paper, we present a new sealing process using epoxy resin and characterizations of two epoxy resins. These resins were characterized by Fourier transform infrared spectroscopic (FTIR), ultraviolet-visible spectroscopy (UV-vis) and differential scanning calorimetry (DSC). Interactions of the resins and of the sealed seeds in a simulated body fluid (SBF) were evaluated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and by a counting gamma-rays. (author)

  5. Retrospective analysis of role of interstitial brachytherapy using template (MUPIT in locally advanced gynecological malignancies

    Directory of Open Access Journals (Sweden)

    Nandwani Pooja

    2007-01-01

    Full Text Available Aim : The aim of this retrospective study was to assess treatment outcomes for patients with locally advanced gynecological malignancies being treated with interstitial brachytherapy using Martinez universal perineal interstitial template (MUPIT and to study the acute and late sequelae and survival after treatment by this technique. Materials and Methods : Ninety seven patients untreated with histopathological confirmation of carcinoma of cervix (37 vault (40 and vagina (20 were treated by combination of external beam RT (EBRT using megavoltage irradiation to pelvis to dose of 4000-5000 cGy followed by interstitial brachytherapy using MUPIT between September 2001 to March 2005. Median age was 46 years. Only those patients who were found unsuitable for conventional brachytherapy or in whom intracavitatory radiotherapy was found to be unlikely to encompass a proper dose distribution were treated by interstitial template brachytherapy using MUPIT application and were enrolled in this study. The dose of MUPIT was 1600-2400 cGy in 4-6# with 400 cGy /# and two fractions a day with minimum gap of six hours in between two fractions on micro-HDR. Criteria for inclusion of patients were as follows: Hb minimum 10 gm/dl, performance status - 70% or more (Karnofsy scale, histopathological confirmation FIGO stage IIB-IIIB (excluding frozen pelvis. Results : Among the 97 patients studied, 12 patients lost to follow-up and hence they were excluded from the study. Follow-up of rest of the patients was then done up to September 2006. The duration of follow-up was in the range of 20-60 months. Parameters studied were local control rate, complication rate, mortality rate and number of patients developing systemic metastasis. Local control was achieved in 56/85 (64.7% and complication rate was 15/85 (17.6%. Local control was better for nonbulky tumors compared bulky tumors irrespective of stage of disease. Local control was better in patients with good regression of

  6. Benefit of Adjuvant Brachytherapy Versus External Beam Radiation for Early Breast Cancer: Impact of Patient Stratification on Breast Preservation

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Grace L. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Jiang, Jing [Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Buchholz, Thomas A. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Xu, Ying [Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hoffman, Karen E. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Giordano, Sharon H. [Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hunt, Kelly K. [Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Smith, Benjamin D., E-mail: bsmith3@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2014-02-01

    Purpose: Brachytherapy after lumpectomy is an increasingly popular breast cancer treatment, but data concerning its effectiveness are conflicting. Recently proposed “suitability” criteria guiding patient selection for brachytherapy have never been empirically validated. Methods: Using the Surveillance, Epidemiology, and End Results–Medicare linked database, we compared women aged 66 years or older with invasive breast cancer (n=28,718) or ductal carcinoma in situ (n=7229) diagnosed from 2002 to 2007, treated with lumpectomy alone, brachytherapy, or external beam radiation therapy (EBRT). The likelihood of breast preservation, measured by subsequent mastectomy risk, was compared by use of multivariate proportional hazards, further stratified by American Society for Radiation Oncology (ASTRO) brachytherapy suitability groups. We compared 1-year postoperative complications using the χ{sup 2} test and 5-year local toxicities using the log-rank test. Results: For patients with invasive cancer, the 5-year subsequent mastectomy risk was 4.7% after lumpectomy alone (95% confidence interval [CI], 4.1%-5.4%), 2.8% after brachytherapy (95% CI, 1.8%-4.3%), and 1.3% after EBRT (95% CI, 1.1%-1.5%) (P<.001). Compared with lumpectomy alone, brachytherapy achieved a more modest reduction in adjusted risk (hazard ratio [HR], 0.61; 95% CI, 0.40-0.94) than achieved with EBRT (HR, 0.22; 95% CI, 0.18-0.28). Relative risks did not differ when stratified by ASTRO suitability group (P=.84 for interaction), although ASTRO “suitable” patients did show a low absolute subsequent mastectomy risk, with a minimal absolute difference in risk after brachytherapy (1.6%; 95% CI, 0.7%-3.5%) versus EBRT (0.8%; 95% CI, 0.6%-1.1%). For patients with ductal carcinoma in situ, EBRT maintained a reduced risk of subsequent mastectomy (HR, 0.40; 95% CI, 0.28-0.55; P<.001), whereas the small number of patients treated with brachytherapy (n=179) precluded definitive comparison with lumpectomy alone

  7. Simulation study on potential accuracy gains from dual energy CT tissue segmentation for low-energy brachytherapy Monte Carlo dose calculations

    Science.gov (United States)

    Landry, Guillaume; Granton, Patrick V.; Reniers, Brigitte; Öllers, Michel C.; Beaulieu, Luc; Wildberger, Joachim E.; Verhaegen, Frank

    2011-10-01

    This work compares Monte Carlo (MC) dose calculations for 125I and 103Pd low-dose rate (LDR) brachytherapy sources performed in virtual phantoms containing a series of human soft tissues of interest for brachytherapy. The geometries are segmented (tissue type and density assignment) based on simulated single energy computed tomography (SECT) and dual energy (DECT) images, as well as the all-water TG-43 approach. Accuracy is evaluated by comparison to a reference MC dose calculation performed in the same phantoms, where each voxel's material properties are assigned with exactly known values. The objective is to assess potential dose calculation accuracy gains from DECT. A CT imaging simulation package, ImaSim, is used to generate CT images of calibration and dose calculation phantoms at 80, 120, and 140 kVp. From the high and low energy images electron density ρe and atomic number Z are obtained using a DECT algorithm. Following a correction derived from scans of the calibration phantom, accuracy on Z and ρe of ±1% is obtained for all soft tissues with atomic number Z in [6,8] except lung. GEANT4 MC dose calculations based on DECT segmentation agreed with the reference within ±4% for 103Pd, the most sensitive source to tissue misassignments. SECT segmentation with three tissue bins as well as the TG-43 approach showed inferior accuracy with errors of up to 20%. Using seven tissue bins in our SECT segmentation brought errors within ±10% for 103Pd. In general 125I dose calculations showed higher accuracy than 103Pd. Simulated image noise was found to decrease DECT accuracy by 3-4%. Our findings suggest that DECT-based segmentation yields improved accuracy when compared to SECT segmentation with seven tissue bins in LDR brachytherapy dose calculation for the specific case of our non-anthropomorphic phantom. The validity of our conclusions for clinical geometry as well as the importance of image noise in the tissue segmentation procedure deserves further

  8. SU-F-BRA-11: An Experimental Commissioning Test of Brachytherapy MBDCA Dosimetry, Based On a Commercial Radiochromic Gel/optical CT System

    Energy Technology Data Exchange (ETDEWEB)

    Pappas, E; Karaiskos, P; Zourari, K; Peppa, V; Papagiannis, P [Medical Physics Laboratory, Medical School, University of Athens (Greece)

    2015-06-15

    Purpose: To implement a 3D dose verification procedure of Model-Based Dose Calculation Algorithms (MBDCAs) for {sup 192}Ir HDR brachytherapy, based on a novel Ferrous Xylenol-orange gel (FXG) and optical CT read-out. Methods: The TruView gel was employed for absolute dosimetry in conjunction with cone-beam optical CT read-out with the VISTA scanner (both from Modus Medical Inc, London, ON, Canada). A multi-catheter skin flap was attached to a cylindrical PETE jar (d=9.6cm, h=16cm) filled with FXG, which served as both the dosimeter and the water equivalent phantom of bounded dimensions. X- ray CT image series of the jar with flap attached was imported to Oncentra Brachy v.4.5. A treatment plan consisting of 8 catheters and 56 dwell positions was generated, and Oncentra-ACE MBDCA as well as TG43 dose results were exported for further evaluation. The irradiation was carried out with a microSelecton v2 source. The FXG dose-response, measured via an electron irradiation of a second dosimeter from the same batch, was linear (R2>0.999) at least up to 12Gy. A MCNP6 input file was prepared from the DICOM-RT plan data using BrachyGuide to facilitate Monte Carlo (MC) simulation dosimetry in the actual experimental geometry. Agreement between experimental (reference) and calculated dose distributions was evaluated using the 3D gamma index (GI) method with criteria (5%-2mm applied locally) determined from uncertainty analysis. Results: The TG-43 GI failed, as expected, in the majority of voxels away from the flap (pass rate 59% for D>0.8Gy, corresponding to 10% of prescribed dose). ACE performed significantly better (corresponding pass rate 92%). The GI evaluation for the MC data (corresponding pass rate 97%) failed mainly at low dose points of increased uncertainty. Conclusion: FXG gel/optical CT is an efficient method for level-2 commissioning of brachytherapy MBDCAs. Target dosimetry is not affected from uncertainty introduced by TG43 assumptions in 192Ir skin brachytherapy

  9. Simulation study on potential accuracy gains from dual energy CT tissue segmentation for low-energy brachytherapy Monte Carlo dose calculations

    Energy Technology Data Exchange (ETDEWEB)

    Landry, Guillaume; Granton, Patrick V; Reniers, Brigitte; Oellers, Michel C; Verhaegen, Frank [Department of Radiation Oncology, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Beaulieu, Luc [Departement de Radio-Oncologie et Centre de Recherche en Cancerologie, Universite Laval, CHUQ Pavillon L' Hotel-Dieu de Quebec, Quebec G1R 2J6 (Canada); Wildberger, Joachim E [Department of Radiology, Maastricht University Medical Center, P. Debijelaan 25, 6229 HX Maastricht (Netherlands)

    2011-10-07

    This work compares Monte Carlo (MC) dose calculations for {sup 125}I and {sup 103}Pd low-dose rate (LDR) brachytherapy sources performed in virtual phantoms containing a series of human soft tissues of interest for brachytherapy. The geometries are segmented (tissue type and density assignment) based on simulated single energy computed tomography (SECT) and dual energy (DECT) images, as well as the all-water TG-43 approach. Accuracy is evaluated by comparison to a reference MC dose calculation performed in the same phantoms, where each voxel's material properties are assigned with exactly known values. The objective is to assess potential dose calculation accuracy gains from DECT. A CT imaging simulation package, ImaSim, is used to generate CT images of calibration and dose calculation phantoms at 80, 120, and 140 kVp. From the high and low energy images electron density {rho}{sub e} and atomic number Z are obtained using a DECT algorithm. Following a correction derived from scans of the calibration phantom, accuracy on Z and {rho}{sub e} of {+-}1% is obtained for all soft tissues with atomic number Z in [6,8] except lung. GEANT4 MC dose calculations based on DECT segmentation agreed with the reference within {+-}4% for {sup 103}Pd, the most sensitive source to tissue misassignments. SECT segmentation with three tissue bins as well as the TG-43 approach showed inferior accuracy with errors of up to 20%. Using seven tissue bins in our SECT segmentation brought errors within {+-}10% for {sup 103}Pd. In general {sup 125}I dose calculations showed higher accuracy than {sup 103}Pd. Simulated image noise was found to decrease DECT accuracy by 3-4%. Our findings suggest that DECT-based segmentation yields improved accuracy when compared to SECT segmentation with seven tissue bins in LDR brachytherapy dose calculation for the specific case of our non-anthropomorphic phantom. The validity of our conclusions for clinical geometry as well as the importance of image noise

  10. Simulation study on potential accuracy gains from dual energy CT tissue segmentation for low-energy brachytherapy Monte Carlo dose calculations.

    Science.gov (United States)

    Landry, Guillaume; Granton, Patrick V; Reniers, Brigitte; Ollers, Michel C; Beaulieu, Luc; Wildberger, Joachim E; Verhaegen, Frank

    2011-10-07

    This work compares Monte Carlo (MC) dose calculations for (125)I and (103)Pd low-dose rate (LDR) brachytherapy sources performed in virtual phantoms containing a series of human soft tissues of interest for brachytherapy. The geometries are segmented (tissue type and density assignment) based on simulated single energy computed tomography (SECT) and dual energy (DECT) images, as well as the all-water TG-43 approach. Accuracy is evaluated by comparison to a reference MC dose calculation performed in the same phantoms, where each voxel's material properties are assigned with exactly known values. The objective is to assess potential dose calculation accuracy gains from DECT. A CT imaging simulation package, ImaSim, is used to generate CT images of calibration and dose calculation phantoms at 80, 120, and 140 kVp. From the high and low energy images electron density ρ(e) and atomic number Z are obtained using a DECT algorithm. Following a correction derived from scans of the calibration phantom, accuracy on Z and ρ(e) of ±1% is obtained for all soft tissues with atomic number Z ∊ [6,8] except lung. GEANT4 MC dose calculations based on DECT segmentation agreed with the reference within ±4% for (103)Pd, the most sensitive source to tissue misassignments. SECT segmentation with three tissue bins as well as the TG-43 approach showed inferior accuracy with errors of up to 20%. Using seven tissue bins in our SECT segmentation brought errors within ±10% for (103)Pd. In general (125)I dose calculations showed higher accuracy than (103)Pd. Simulated image noise was found to decrease DECT accuracy by 3-4%. Our findings suggest that DECT-based segmentation yields improved accuracy when compared to SECT segmentation with seven tissue bins in LDR brachytherapy dose calculation for the specific case of our non-anthropomorphic phantom. The validity of our conclusions for clinical geometry as well as the importance of image noise in the tissue segmentation procedure deserves

  11. Recommendations from gynaecological (GYN) GEC ESTRO working group (II): concepts and terms in 3D image-based treatment planning in cervix cancer brachytherapy-3D dose volume parameters and aspects of 3D image-based anatomy, radiation physics, radiobiology.

    Science.gov (United States)

    Pötter, Richard; Haie-Meder, Christine; Van Limbergen, Erik; Barillot, Isabelle; De Brabandere, Marisol; Dimopoulos, Johannes; Dumas, Isabelle; Erickson, Beth; Lang, Stefan; Nulens, An; Petrow, Peter; Rownd, Jason; Kirisits, Christian

    2006-01-01

    The second part of the GYN GEC ESTRO working group recommendations is focused on 3D dose-volume parameters for brachytherapy of cervical carcinoma. Methods and parameters have been developed and validated from dosimetric, imaging and clinical experience from different institutions (University of Vienna, IGR Paris, University of Leuven). Cumulative dose volume histograms (DVH) are recommended for evaluation of the complex dose heterogeneity. DVH parameters for GTV, HR CTV and IR CTV are the minimum dose delivered to 90 and 100% of the respective volume: D90, D100. The volume, which is enclosed by 150 or 200% of the prescribed dose (V150, V200), is recommended for overall assessment of high dose volumes. V100 is recommended for quality assessment only within a given treatment schedule. For Organs at Risk (OAR) the minimum dose in the most irradiated tissue volume is recommended for reporting: 0.1, 1, and 2 cm3; optional 5 and 10 cm3. Underlying assumptions are: full dose of external beam therapy in the volume of interest, identical location during fractionated brachytherapy, contiguous volumes and contouring of organ walls for >2 cm3. Dose values are reported as absorbed dose and also taking into account different dose rates. The linear-quadratic radiobiological model-equivalent dose (EQD2)-is applied for brachytherapy and is also used for calculating dose from external beam therapy. This formalism allows systematic assessment within one patient, one centre and comparison between different centres with analysis of dose volume relations for GTV, CTV, and OAR. Recommendations for the transition period from traditional to 3D image-based cervix cancer brachytherapy are formulated. Supplementary data (available in the electronic version of this paper) deals with aspects of 3D imaging, radiation physics, radiation biology, dose at reference points and dimensions and volumes for the GTV and CTV (adding to [Haie-Meder C, Pötter R, Van Limbergen E et al. Recommendations from

  12. Interstitial brachytherapy for liver metastases and assessment of response by positron emission tomography: a case report

    Directory of Open Access Journals (Sweden)

    Goura Kishor Rath

    2010-10-01

    Full Text Available For liver metastases (LM, image guided percutaneous ablative procedures such as radiofrequency ablation (RFA, laser induced thermal therapy (LITT and trans-arterial chemo-embolisation (TACE are increasingly being used because they are relatively safer, less invasive and equally effective. CT scan guided interstitial brachytherapy (IBT with a single large dose of radiation by high dose rate (HDR brachytherapy is a novel technique of treating LM and has shown good results. Positron emission tomography (PET scan may provide better information for assessing the response toIBT procedures. We hereby report a case of LM that was treated by HDR IBT and PET scan was done in addition to CT scan for assessing the response.

  13. Dosimetry in HDR brachytherapy with Fricke-gel layers and Fricke-gel catheters

    Energy Technology Data Exchange (ETDEWEB)

    Gambarini, G; Carrara, M; Negri, A; Invernizzi, M; Tenconi, C; Scotti, A; Pirola, L; Borroni, M; Tomatis, S; Fallai, C, E-mail: grazia.gambarini@mi.infn.i

    2010-11-01

    Fricke-gel layer dosimeters (FGLD) and Fricke gel dosimetric catheters (FGDC) have been designed and tested with the aim of enquiring their suitability for HDR {sup 192}Ir brachytherapy source control and for in-vivo dose verification during treatment. Anisotropy function measurements have been carried out with FGLDs in which a thin plastic tube has been placed in for the {sup 192}Ir source insertion. FGDCs are constituted by plastic tubes (3 mm of external diameter and 13 cm of length) filled with the dosimeter-gel. Absorbed dose images and profiles were attained by means of optical analysis. Dedicated software has been developed both for achieving anisotropy function values and for obtaining reliable results in visible light absorbance measurements across the thin cylindrical dosimeters. Preparation and analysis procedures have been optimised. The results confirm that the proposed methods are very promising for HDR brachytherapy dosimetry.

  14. Dosimetric equivalence of non-standard high dose rate (HDR) brachytherapy catheter patterns

    CERN Document Server

    Cunha, J Adam M; Pouliot, Jean

    2009-01-01

    Purpose: To determine whether alternative HDR prostate brachytherapy catheter patterns can result in improved dose distributions while providing better access and reducing trauma. Methods: Prostate HDR brachytherapy uses a grid of parallel needle positions to guide the catheter insertion. This geometry does not easily allow the physician to avoid piercing the critical structures near the penile bulb nor does it provide position flexibility in the case of pubic arch interference. On CT data from ten previously-treated patients new catheters were digitized following three catheter patterns: conical, bi-conical, and fireworks. The conical patterns were used to accommodate a robotic delivery using a single entry point. The bi-conical and fireworks patterns were specifically designed to avoid the critical structures near the penile bulb. For each catheter distribution, a plan was optimized with the inverse planning algorithm, IPSA, and compared with the plan used for treatment. Irrelevant of catheter geometry, a p...

  15. Isodose curve determination of prostate for the treatment of brachytherapy using MCNPX code

    Energy Technology Data Exchange (ETDEWEB)

    Reis Junior, J.P.; Menezes, A.F.; Medeiros, J.A.C.C., E-mail: jjunior@con.ufrj.br, E-mail: ademir@con.ufrj.br, E-mail: amenezes@con.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ/COPPE/PEN), RJ (Brazil). Coord. dos Programas de Pos-Graduacao em Engenharia. Programa de Engenharia Nuclear; Salmom, H.A., E-mail: heliosalmom@coinet.com.br [MD.X Barra Medical Center, Barra da Tijuca, Rio de Janeiro, RJ (Brazil); Facure, A.N.S.S., E-mail: facure@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Silva, A.X. [Universidade Federal do Rio de Janeiro (UFRJ/DEN), Rio de Janeiro, RJ (Brazil). Escola Politecnica. Dept. de Engenharia Nuclear

    2011-07-01

    Using voxel phantom MAX 06 coupled to the code MCNPX it possible to plot the isodose curves for the main levels involved in the treatment of prostate brachytherapy, V100 and V150 which are, respectively corresponding curves 144 and 216 Gy to curves are indicative of the quality of the existing implant of prostate brachytherapy. The number of 79 seeds {sup 125}I, were placed in the voxels simulator MAX 06, in the slices x = 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0 with the calculation model used in MCNPX in all voxels present in a matrix, it was possible to trace the isodose curves for MATLAB. For comparison and using own routines MCNPX it was possible to trace the same curves using mesh tallies. The results showed agreement with predicted values in the planning system prowess 3D. (author)

  16. Plastic optical fibre sensor for in-vivo radiation monitoring during brachytherapy

    Science.gov (United States)

    Woulfe, P.; Sullivan, F. J.; Lewis, E.; O'Keeffe, S.

    2015-09-01

    An optical fibre sensor is presented for applications in real-time in-vivo monitoring of the radiation dose a cancer patient receives during seed implantation in Brachytherapy. The sensor is based on radioluminescence whereby radiation sensitive scintillation material is embedded in the core of a 1mm plastic optical fibre. Three scintillation materials are investigated: thallium-doped caesium iodide (CsI:Tl), terbium-doped gadolinium oxysulphide (Gd2O2S:Tb) and europium-doped lanthanum oxysulphide (La2O2S:Eu). Terbium-doped gadolinium oxysulphide was identified as being the most suitable scintillator and further testing demonstrates its measureable response to different activities of Iodine-125, the radio-active source commonly used in Brachytherapy for treating prostate cancer.

  17. Quality control for cervical cancer treatments on Hdr brachytherapy with Ir-192

    Energy Technology Data Exchange (ETDEWEB)

    Alvarino B, G.; Cogollo P, R.; Paez M, M., E-mail: lvarinog@hotmail.com [Universidad de Cordoba, Physics and Electronics Department, Carrera 6 No. 76-103, Monteria, Cordoba (Colombia)

    2013-10-01

    This work, developed at the National Cancer Institute in partnership with Universidad Nacional de Colombia located in Bogota, Colombia, presents the results of simulations of cervical cancer treatments, on Hdr brachytherapy with Ir-192, using as a physical simulator a natural female pelvis bone with soft tissue elaborated with the experimental material JJT. The doses were measured experimentally, prior to dosimetric characterization, with crystal thermoluminescence 100 LiF: Mg, Ti, located in the organs at risk: rectum and bladder. On the other hand, these treatments were planned and calculated theoretically by the system Micro-Selectron Hdr, with Plato brachytherapy software V 14.1 from the Netherlands Nucletron, and doses obtained in the same organs were compared with experimental results using dosimeters. The comparison of these results shows the correlation degree between the planning of dosimetric treatments and the experimental results, making the process in a form of quality control in vivo, of this type of procedure. (Author)

  18. Intracoronary brachytherapy in the treatment of in-stent restenosis. Initial experience in Brazil

    Directory of Open Access Journals (Sweden)

    Fábio Sândoli de Brito Jr

    2001-09-01

    Full Text Available Intracoronary brachytherapy using beta or gamma radiation is currently the most efficient type of therapy for preventing the recurrence of coronary in-stent restenosis. Its implementation depends on the interaction among interventionists, radiotherapists, and physicists to assure the safety and quality of the method. The authors report the pioneering experience in Brazil of the treatment of 2 patients with coronary in-stent restenosis, in whom beta radiation was used as part of the international multicenter randomized PREVENT study (Proliferation REduction with Vascular ENergy Trial. The procedures were performed rapidly and did not require significant modifications in the traditional techniques used for conventional angioplasty. Alteration in the radiological protection devices of the hemodynamic laboratory were also not required, showing that intracoronary brachytherapy using beta radiation can be incorporated into the interventional tools of cardiology in our environment.

  19. European research projects for metrology in Brachytherapy and External Beam Cancer Therapy

    Science.gov (United States)

    Ankerhold, Ulrike; Toni, Maria Pia

    2012-10-01

    In 2008, within the framework of the European Metrology Research Programme (EMRP), two projects were launched with the central objective of providing reliable measuring techniques for the methods of modern cancer therapy using ionizing radiation—such as brachytherapy, intensity modulated radiation therapy and hadron therapy—and using high intensity therapeutic ultrasound. The two three-year projects are ‘Increasing cancer treatment efficacy using 3D brachytherapy’ (Brachytherapy) and ‘External Beam Cancer Therapy’ (EBCT). For these modern treatment methods there is an urgent requirement for establishing a sound metrological basis with regard to the radiation dose delivered and its spatial distribution. This paper gives a brief overview about the two projects' work, their goals and findings. The details of the projects' work and their outcomes are presented within these conference proceedings or in the cited publications.

  20. Anatomy-based three-dimensional dose optimization in brachytherapy using multiobjective genetic algorithms.

    Science.gov (United States)

    Lahanas, M; Baltas, D; Zamboglou, N

    1999-09-01

    In conventional dose optimization algorithms, in brachytherapy, multiple objectives are expressed in terms of an aggregating function which combines individual objective values into a single utility value, making the problem single objective, prior to optimization. A multiobjective genetic algorithm (MOGA) was developed for dose optimization based on an a posteriori approach, leaving the decision-making process to a planner and offering a representative trade-off surface of the various objectives. The MOGA provides a flexible search engine which provides the maximum of information for a decision maker. Tests performed with various treatment plans in brachytherapy have shown that MOGA gives solutions which are superior to those of traditional dose optimization algorithms. Objectives were proposed in terms of the COIN distribution and differential volume histograms, taking into account patient anatomy in the optimization process.

  1. An orthodontic device for retaining implanted radioactive sources during brachytherapy for cancer of the oral cavity

    Energy Technology Data Exchange (ETDEWEB)

    Masuko, Noriko; Katsura, Kouji [Niigata Univ. (Japan). School of Dentistry; Sugita, Tadashi; Sakai, Kunio; Sato, Katsurou; Kawana, Masahiro; Nonomura, Naobumi

    2000-03-01

    An orthodontic retainer was devised to keeping implanted radioactive sources in position and improve the quality of life during brachytherapy for cancer of the oral cavity. The retainer was used in 3 patients with oral cancer, one with cancer of the hard palate, one with cancer of the soft palate, and one with cancer of the floor of mouth, during brachytherapy using {sup 198}Au grains and {sup 137}Cs needles. These patients could speak freely. One with cancer of the hard palate could drink water and ingest semi-liquid food during treatment instead of nasal tube feeding. The plaster dental model obtained while making the retainer proved to be useful for training radiation oncologists. (author)

  2. Reduction in radiation exposure to nursing personnel with the use of remote afterloading brachytherapy devices

    Energy Technology Data Exchange (ETDEWEB)

    Grigsby, P.W.; Perez, C.A.; Eichling, J.; Purdy, J.; Slessinger, E. (Mallinckrodt Institute of Radiology, St. Louis, MO (USA))

    1991-03-01

    The radiation exposure to nursing personnel from patients with brachytherapy implants on a large brachytherapy service were reviewed. Exposure to nurses, as determined by TLD monitors, indicates a 7-fold reduction in exposure after the implementation of the use of remote afterloading devices. Quarterly TLD monitor data for six quarters prior to the use of remote afterloading devices demonstrate an average projected annual dose equivalent to the nurses of 152 and 154 mrem (1.5 mSv). After the implementation of the remote afterloading devices, the quarterly TLD monitor data indicate an average dose equivalent per nurse of 23 and 19 mrem (0.2 mSv). This is an 87% reduction in exposure to nurses with the use of these devices (p less than 0.01).

  3. SU-E-T-786: Utility of Gold Wires to Optimize Intensity Modulation Capacity of a Novel Directional Modulated Brachytherapy Tandem Applicator for Image Guided Cervical Cancer Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Han, D [University of California, San Diego, La Jolla, CA (United States); Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Safigholi, H; Soliman, A; Song, W [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Scanderbeg, D [University of California, San Diego, La Jolla, CA (United States); UCSD Medical Center, La Jolla, CA (United States); Liu, Z [University of California, San Diego, La Jolla, CA (United States)

    2015-06-15

    Purpose: To evaluate the impact of using gold wires to differentially fill various channels on plan quality compared with conventional T&R applicator, inside a novel directional modulated brachytherapy (DMBT) tandem applicator for cervical cancer brachytherapy. Materials and Methods: The novel DMBT tandem applicator has a 5.4-mm diameter MR-compatible tungsten alloy enclosed in a 0.3-mm thick plastic tubing that wraps around the tandem. To modulate the radiation intensity, 6 symmetric peripheral holes of 1.3-mm diameter are grooved along the tungsten alloy rod. These grooved holes are differentially filled with gold wires to generate various degrees of directional beams. For example, three different fill patterns of 1) all void, 2) all filled except the hole containing the 192-Ir source, and 3) two adjacent holes to the 192-Ir source filled were Monte Carlo simulated. The resulting 3D dose distributions were imported into an in-house-coded inverse optimization planning system to generate HDR brachytherapy clinical plans for 19 patient cases. All plans generated were normalized to the same D90 as the clinical plans and D2cc doses of OARs were evaluated. Prescription ranged between 15 and 17.5Gy. Results: In general, the plans in case 1) resulted in the highest D2cc doses for the OARs with 11.65±2.30Gy, 7.47±3.05Gy, and 9.84±2.48Gy for bladder, rectum, and sigmoid, respectively, although the differences were small. For the case 2), D2cc doses were 11.61±2.29Gy, 7.41±3.07Gy, and 9.75±2.45Gy, respectively. And, for the case 3), D2cc doses were 11.60±2.28Gy, 7.41±3.05Gy, and 9.74±2.45Gy, respectively. Difference between 1) and 2) cases were small with the average D2cc difference of <0.64%. Difference between 1) and 3) cases were even smaller with the average D2cc difference of <0.1%. Conclusions: There is a minimal clinical benefit by differentially filling grooved holes in the novel DMBT tandem applicator for image guided cervical cancer brachytherapy.

  4. ENT COBRA (Consortium for Brachytherapy Data Analysis): interdisciplinary standardized data collection system for head and neck patients treated with interventional radiotherapy (brachytherapy)

    OpenAIRE

    2016-01-01

    Purpose Aim of the COBRA (Consortium for Brachytherapy Data Analysis) project is to create a multicenter group (consortium) and a web-based system for standardized data collection. Material and methods GEC-ESTRO (Groupe Européen de Curiethérapie – European Society for Radiotherapy & Oncology) Head and Neck (H&N) Working Group participated in the project and in the implementation of the consortium agreement, the ontology (data-set) and the necessary COBRA software services as well as the peer ...

  5. Endoscope-guided interstitial intensity-modulated brachytherapy and intracavitary brachytherapy as boost radiation for primary early T stage nasopharyngeal carcinoma.

    Directory of Open Access Journals (Sweden)

    Xiang-Bo Wan

    Full Text Available BACKGROUND: Intracavitary brachytherapy (ICBT is usually applied as boost radiotherapy for superficial residual of nasopharyngeal carcinoma (NPC after primary extern-beam radiptherapy (ERT. Here, we evaluated the outcome of endoscope-guided interstitial intensity-modulated brachytherapy (IMBT boost radiation for deep-seated residual NPC. METHODOLOGY/PRINCIPAL FINDINGS: Two hundred and thirteen patients with residual NPC who were salvaged with brachytherapy boost radiation during 2005-2009 were analyzed retrospectively. Among these patients, 171 patients had superficial residual NPC (≤1 cm below the nasopharyngeal epithelium were treated with ICBT boost radiation, and interstitial IMBT boost radiation was delivered to 42 patients with deep-seated residual NPC (>1 cm below the nasopharyngeal epithelium. We found that IMBT boost subgroup had a higher ratio of T2b (81.0% VS 34.5%, P<0.001 and stage II (90.5% VS 61.4%, P = 0.001 than that of ICBT boost subgroup. The dosage of external-beam radiotherapy in the nasopharyngeal (63.0±3.8 VS 62.6±4.3 Gray (Gy, P = 0.67 and regional lymph nodes (55.8±5.0 VS 57.5±5.7 Gy, P = 0.11 was comparable in both groups. For brachytherapy, IMBT subgroup had a lower boost radiation dosage than ICBT subgroup (11.0±2.9 VS 14.8±3.2 Gy, P<0.01. Though the IMBT group had deeper residual tumors and received lower boost radiation dosages, both subgroups had the similar 5-year actuarial overall survival rate (IMBT VS ICBT group: 96.8% VS 93.6%, P = 0.87, progression-free survival rate (92.4% VS 86.5%, P = 0.41 and distant metastasis-free survival rate (94.9% VS 92.7%, P = 0.64. Moreover, IMBT boost radiation subgroup had a similar local (97.4% VS 94.4%, P = 0.57 and regional (95.0% VS 97.2%, P = 0.34 control to ICBT subgroup. The acute and late toxicities rates were comparable between the both subgroups. CONCLUSIONS/SIGNIFICANCE: IMBT boost radiation may be a promising therapeutic

  6. The dosimetric feasibility of gold nanoparticle-aided radiation therapy (GNRT) via brachytherapy using low-energy gamma-/x-ray sources.

    Science.gov (United States)

    Cho, Sang Hyun; Jones, Bernard L; Krishnan, Sunil

    2009-08-21

    The preferential accumulation of gold nanoparticles within tumors and the increased photoelectric absorption due to the high atomic number of gold cooperatively account for the possibility of significant tumor dose enhancement during gold nanoparticle-aided radiation therapy (GNRT). Among the many conceivable ways to implement GNRT clinically, a brachytherapy approach using low-energy gamma-/x-ray sources (i.e. E(avg) 40%) could be achievable using (125)I, 50 kVp and (169)Yb sources and gold nanoparticles. When calculated at 1.0 cm from the center of the source within a tumor loaded with 18 mg Au g(-1), macroscopic dose enhancement was 116, 92 and 108% for (125)I, 50 kVp and (169)Yb, respectively. For a tumor loaded with 7 mg Au g(-1), it was 68, 57 and 44% at 1 cm from the center of the source for (125)I, 50 kVp and (169)Yb, respectively. The estimated MDEF values for (169)Yb were remarkably larger than those for (192)Ir, on average by up to about 70 and 30%, for 18 mg Au and 7 mg Au cases, respectively. The current MC study also shows a remarkable change in the photoelectron fluence and spectrum (e.g. more than two orders of magnitude) and a significant production (e.g. comparable to the number of photoelectrons) of the Auger electrons within the tumor region due to the presence of gold nanoparticles during low-energy gamma-/x-ray irradiation. The radiation sources considered in this study are currently available and tumor gold concentration levels considered in this investigation are deemed achievable. Therefore, the current results strongly suggest that GNRT can be successfully implemented via brachytherapy with low energy gamma-/x-ray sources, especially with a high dose rate (169)Yb source.

  7. Metal artifact reduction in MRI-based cervical cancer intracavitary brachytherapy

    Science.gov (United States)

    Rao, Yuan James; Zoberi, Jacqueline E.; Kadbi, Mo; Grigsby, Perry W.; Cammin, Jochen; Mackey, Stacie L.; Garcia-Ramirez, Jose; Goddu, S. Murty; Schwarz, Julie K.; Gach, H. Michael

    2017-04-01

    Magnetic resonance imaging (MRI) plays an increasingly important role in brachytherapy planning for cervical cancer. Yet, metal tandem, ovoid intracavitary applicators, and fiducial markers used in brachytherapy cause magnetic susceptibility artifacts in standard MRI. These artifacts may impact the accuracy of brachytherapy treatment and the evaluation of tumor response by misrepresenting the size and location of the metal implant, and distorting the surrounding anatomy and tissue. Metal artifact reduction sequences (MARS) with high bandwidth RF selective excitations and turbo spin-echo readouts were developed for MRI of orthopedic implants. In this study, metal artifact reduction was applied to brachytherapy of cervical cancer using the orthopedic metal artifact reduction (O-MAR) sequence. O-MAR combined MARS features with view angle tilting and slice encoding for metal artifact correction (SEMAC) to minimize in-plane and through-plane susceptibility artifacts. O-MAR improved visualization of the tandem tip on T2 and proton density weighted (PDW) imaging in phantoms and accurately represented the diameter of the tandem. In a pilot group of cervical cancer patients (N  =  7), O-MAR significantly minimized the blooming artifact at the tip of the tandem in PDW MRI. There was no significant difference observed in artifact reduction between the weak (5 kHz, 7 z-phase encodes) and medium (10 kHz, 13 z-phase encodes) SEMAC settings. However, the weak setting allowed a significantly shorter acquisition time than the medium setting. O-MAR also reduced susceptibility artifacts associated with metal fiducial markers so that they appeared on MRI at their true dimensions.

  8. Evaluation of PC-ISO for customized, 3D printed, gynecologic 192Ir HDR brachytherapy applicators.

    Science.gov (United States)

    Cunha, J Adam M; Mellis, Katherine; Sethi, Rajni; Siauw, Timmy; Sudhyadhom, Atchar; Garg, Animesh; Goldberg, Ken; Hsu, I-Chow; Pouliot, Jean

    2015-01-01

    The purpose of this study was to evaluate the radiation attenuation properties of PC-ISO, a commercially available, biocompatible, sterilizable 3D printing material, and its suitability for customized, single-use gynecologic (GYN) brachytherapy applicators that have the potential for accurate guiding of seeds through linear and curved internal channels. A custom radiochromic film dosimetry apparatus was 3D-printed in PC-ISO with a single catheter channel and a slit to hold a film segment. The apparatus was designed specifically to test geometry pertinent for use of this material in a clinical setting. A brachytherapy dose plan was computed to deliver a cylindrical dose distribution to the film. The dose plan used an 192Ir source and was normalized to 1500 cGy at 1 cm from the channel. The material was evaluated by comparing the film exposure to an identical test done in water. The Hounsfield unit (HU) distributions were computed from a CT scan of the apparatus and compared to the HU distribution of water and the HU distribution of a commercial GYN cylinder applicator. The dose depth curve of PC-ISO as measured by the radiochromic film was within 1% of water between 1 cm and 6 cm from the channel. The mean HU was -10 for PC-ISO and -1 for water. As expected, the honeycombed structure of the PC-ISO 3D printing process created a moderate spread of HU values, but the mean was comparable to water. PC-ISO is sufficiently water-equivalent to be compatible with our HDR brachytherapy planning system and clinical workflow and, therefore, it is suitable for creating custom GYN brachytherapy applicators. Our current clinical practice includes the use of custom GYN applicators made of commercially available PC-ISO when doing so can improve the patient's treatment. PACS number: none.

  9. Evaluation of PC-ISO for customized, 3D Printed, gynecologic 192-Ir HDR brachytherapy applicators.

    Science.gov (United States)

    Cunha, J Adam M; Mellis, Katherine; Sethi, Rajni; Siauw, Timmy; Sudhyadhom, Atchar; Garg, Animesh; Goldberg, Ken; Hsu, I-Chow; Pouliot, Jean

    2015-01-08

    The purpose of this study was to evaluate the radiation attenuation properties of PC-ISO, a commercially available, biocompatible, sterilizable 3D printing material, and its suitability for customized, single-use gynecologic (GYN) brachytherapy applicators that have the potential for accurate guiding of seeds through linear and curved internal channels. A custom radiochromic film dosimetry apparatus was 3D-printed in PC-ISO with a single catheter channel and a slit to hold a film segment. The apparatus was designed specifically to test geometry pertinent for use of this material in a clinical setting. A brachytherapy dose plan was computed to deliver a cylindrical dose distribution to the film. The dose plan used an 192Ir source and was normalized to 1500 cGy at 1 cm from the channel. The material was evaluated by comparing the film exposure to an identical test done in water. The Hounsfield unit (HU) distributions were computed from a CT scan of the apparatus and compared to the HU distribution of water and the HU distribution of a commercial GYN cylinder applicator. The dose depth curve of PC-ISO as measured by the radiochromic film was within 1% of water between 1 cm and 6 cm from the channel. The mean HU was -10 for PC-ISO and -1 for water. As expected, the honeycombed structure of the PC-ISO 3D printing process created a moderate spread of HU values, but the mean was comparable to water. PC-ISO is sufficiently water-equivalent to be compatible with our HDR brachytherapy planning system and clinical workflow and, therefore, it is suitable for creating custom GYN brachytherapy applicators. Our current clinical practice includes the use of custom GYN applicators made of commercially available PC-ISO when doing so can improve the patient's treatment. 

  10. High-dose rate brachytherapy in the treatment of cancer of the cervix uteri

    Directory of Open Access Journals (Sweden)

    D. A. Aliyev

    2011-01-01

    Full Text Available Analysis of the results of examining and treating 246 patients with Stages IIA-IIIB cancer of the cervix uteri (CCU, receiving specific chemoradiotherapy (CRT at the Department of Radiotherapy, National Oncology Center (Baku, has ascertained that CRT using two high-dose (9 Gy rate brachytherapy fractions and competitive cisplatin chemotherapy is an effective, reasonably safe, and economically sound treatment method for locally advanced CCU. The method shows acceptable toxicity and may be used in routine clinical practice.

  11. SU-E-T-366: Clinical Implementation of MR-Guided Vaginal Cylinder Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Owrangi, A; Jolly, S; Balter, J; Cao, Y; Young, L; Zhu, T; Prisciandaro, J [University of Michigan, Ann Arbor, MI (United States)

    2014-06-01

    Purpose: To evaluate the accuracy of MR-based vaginal brachytherapy source localization using an in-house MR-visible marker versus the alignment of an applicator model to MR images. Methods: Three consecutive patients undergoing vaginal HDR brachytherapy with a plastic cylinder were scanned with both CT and MRI (including T1- and T2- weighted images). An MR-visible source localization marker, consisting of a sealed thin catheter filled with either water (for T2 contrast) or Gd-doped water (for T1 contrast), was assembled shortly before scanning. Clinically, the applicator channel was digitized on CT with an x-ray marker. To evaluate the efficacy of MR-based applicator reconstruction, each MR image volume was aligned locally to the CT images based on the region containing the cylinder. Applicator digitization was performed on the MR images using (1) the MR visible marker and (2) alignment of an applicator surface model from Varian's Brachytherapy Planning software to the MRI images. Resulting source positions were compared with the original CT digitization. Results: Although the source path was visualized by the MR marker, the applicator tip proved difficult to identify due to challenges in achieving a watertight seal. This resulted in observed displacements of the catheter tip, at times >1cm. Deviations between the central source positions identified via aligning the applicator surface model to MR and using the xray marker on CT ranged from 0.07 – 0.19 cm and 0.07 – 0.20 cm on T1- weighted and T2-weighted images, respectively. Conclusion: Based on the current study, aligning the applicator model to MRI provides a practical, current approach to perform MR-based brachytherapy planning. Further study is needed to produce catheters with reliably and reproducibly identifiable tips. Attempts are being made to improve catheter seals, as well as to increase the viscosity of the contrast material to decrease fluid mobility inside the catheter.

  12. Computed tomography-ultrasound fusion brachytherapy: description and evolution of the technique.

    Science.gov (United States)

    Fuller, Donald B; Jin, Haoran

    2007-01-01

    In this manuscript, we describe our computed tomography (CT)-ultrasound (US) fusion prostate brachytherapy method and report the updated dosimetry result and trend. This cohort of 132 consecutive patients received CT-US fusion prostate brachytherapy from the first author (DBF) from December 2002 to August 2006. The technique consists of a hybrid preplanned and intraoperative dynamic dosimetry method, which initially delivers a standard preplanned source distribution, and then uses interval CT-based source identification dosimetry, fused to an identically spaced intraoperative US volume study series, to direct remedial sources that correct initial dosimetry deficiencies. The median and minimum prostate Day 0 prostate volume of interest receiving 100% of prescribed dose (V(100)) results in this patient cohort measured 98.26% and 92.61%, respectively, with all Day 0 prostate dose received by 90% of the volume of interest (D(90)) results exceeding 100% of the prescribed dose, and the maximum Day 0 prostate D(90) value measuring 128% of the prescribed dose. During the period of this analysis, a trend to the decreased quantity of dynamic remedial millicuries per case was identified, with the total sources decreasing from 116% to 106% of the preplanned level, resulting in minimal V(100) and D(90) decreases, while continuing to exceed the minimum Day 0 dosimetry requirements. CT-US fusion dynamic prostate brachytherapy represents a consistent prostate brachytherapy dosimetry delivery mechanism, creating a tight lower and upper bound to the final Day 0 prostate V(100) and D(90) parameters. The practice and pitfalls of this technique are discussed in detail.

  13. CT-Based Brachytherapy Treatment Planning using Monte Carlo Simulation Aided by an Interface Software

    Directory of Open Access Journals (Sweden)

    Vahid Moslemi

    2011-03-01

    Full Text Available Introduction: In brachytherapy, radioactive sources are placed close to the tumor, therefore, small changes in their positions can cause large changes in the dose distribution. This emphasizes the need for computerized treatment planning. The usual method for treatment planning of cervix brachytherapy uses conventional radiographs in the Manchester system. Nowadays, because of their advantages in locating the source positions and the surrounding tissues, CT and MRI images are replacing conventional radiographs. In this study, we used CT images in Monte Carlo based dose calculation for brachytherapy treatment planning, using an interface software to create the geometry file required in the MCNP code. The aim of using the interface software is to facilitate and speed up the geometry set-up for simulations based on the patient’s anatomy. This paper examines the feasibility of this method in cervix brachytherapy and assesses its accuracy and speed. Material and Methods: For dosimetric measurements regarding the treatment plan, a pelvic phantom was made from polyethylene in which the treatment applicators could be placed. For simulations using CT images, the phantom was scanned at 120 kVp. Using an interface software written in MATLAB, the CT images were converted into MCNP input file and the simulation was then performed. Results: Using the interface software, preparation time for the simulations of the applicator and surrounding structures was approximately 3 minutes; the corresponding time needed in the conventional MCNP geometry entry being approximately 1 hour. The discrepancy in the simulated and measured doses to point A was 1.7% of the prescribed dose.  The corresponding dose differences between the two methods in rectum and bladder were 3.0% and 3.7% of the prescribed dose, respectively. Comparing the results of simulation using the interface software with those of simulation using the standard MCNP geometry entry showed a less than 1

  14. Adjuvant radiotherapy in Stage II endometrial carcinoma: Is brachytherapy alone sufficient for local control?

    Science.gov (United States)

    Paydar, Ima; DeWees, Todd; Powell, Matthew; Mutch, David G; Grigsby, Perry W; Schwarz, Julie K

    2015-01-01

    To evaluate recurrence patterns and overall survival in patients treated with adjuvant radiation after surgical staging for Stage II endometrial carcinoma. Secondary goals include identification of prognostic factors for recurrence and toxicity assessment. The medical records of 41 patients treated with adjuvant radiotherapy at Washington University School of Medicine after surgical staging for endometrial cancer (total abdominal hysterectomy and bilateral salpingo-oophorectomy, peritoneal cytology, lymph node dissection) were reviewed. Nineteen were treated with a combination of external beam radiotherapy and vaginal brachytherapy (VB), and 22 patients were treated with postoperative VB alone. Median followup for all patients was 41 months. Median patient age was 59 years (range, 42-87 years). All tumors were of endometrioid histology. There were 20 Grade 1 tumors, 13 Grade 2 tumors, and 8 Grade 3 tumors. For all patients, the 5-year overall survival was 69.8%, and the 5-year recurrence-free survival was 89.0%. There was no statistically significant difference in overall survival (p = 0.510) or freedom from vaginal (p = 0.840), distant (p = 0.133), or any recurrence (p = 0.275) with respect to modality of treatment (external beam radiotherapy and VB vs. VB alone). There were no pelvic lymph node recurrences. In the univariate analysis, there were no risk factors influencing overall survival or recurrences. One patient experienced a toxicity requiring hospital admission. She was treated with pelvic external beam radiation plus brachytherapy. VB alone results in excellent local control for patients with Stage II endometrial cancer after surgical staging. Long-term toxicities are rare and more common in the group of patients who were treated with pelvic external beam plus brachytherapy. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  15. Impact of comorbidity in elderly prostate cancer patients treated with brachytherapy

    Institute of Scientific and Technical Information of China (English)

    Costanza Chiumento; Alba Fiorentino; Mariella Cozzolino; Rocchina Caivano; Stefania Clemente; Piernicola Pedicini; Vincenzo Fusco

    2013-01-01

    Objective:To analyze the correlations among comorbidity and overall survival (OS),biochemical progression-free survival (b-PFS) and toxicity in elderly patents with localized prostate cancer treated with 125I brachytherapy.Methods:Elderly men,aged ≥65 years,with low-intermediate risk prostate cancer,were treated with permanent 125I brachytherapy as monotherapy.Comorbidity data were obtained from medical reports using age-adjusted Charlson comorbidity index (a-CCI).The patients were categorized into two age groups (<75and ≥75 years old),and two comorbidity score groups (a-CCI ≤3 and >3).Toxicity was scored with Radiation Therapy Oncology Group (RTOG) scale.Results:From June 2003 to October 2009,a total of 92 elderly patients underwent prostate brachytherapy,including 57 men (62%) with low-risk prostate cancer,and 35 men (38%) with intermediate-risk prostate cancer.The median age of patients was 75 years (range,65-87 years).Forty-seven patients (51%) had a-CCI ≤3 and 45 patients (49%) a-CCI >3.With a median follow-up period of 56 months (range,24-103 months),the 5-year actuarial OS and b-PFS were 91.3% and 92.4% respectively,without statistical significance between two Charlson score groups.Toxicity was mild.None of the patients experienced gastrointestinal (GI) toxicity,and only 4 patiens (4%) experienced late genitourinary (GU) grade-3 (G3) toxicity.No correlation between acute GU and GI toxicity and comorbidity was showed (P=0.50 and P=0.70,respectively).Conclusions:Our data suggest that elderly men with low-intermediate risk prostate cancer and comorbidity can be considered for a radical treatment as 125I low-dose rate brachytherapy.

  16. A comparison of inverse optimization algorithms for HDR/PDR prostate brachytherapy treatment planning.

    Science.gov (United States)

    Dinkla, Anna M; van der Laarse, Rob; Kaljouw, Emmie; Pieters, Bradley R; Koedooder, Kees; van Wieringen, Niek; Bel, Arjan

    2015-01-01

    Graphical optimization (GrO) is a common method for high-dose-rate/pulsed-dose-rate (PDR) prostate brachytherapy treatment planning. New methods performing inverse optimization of the dose distribution have been developed over the past years. The purpose is to compare GrO and two established inverse methods, inverse planning simulated annealing (IPSA) and hybrid inverse treatment planning and optimization (HIPO), and one new method, enhanced geometric optimization-interactive inverse planning (EGO-IIP), in terms of speed and dose-volume histogram (DVH) parameters. For 26 prostate cancer patients treated with a PDR brachytherapy boost, an experienced treatment planner optimized the dose distributions using four different methods: GrO, IPSA, HIPO, and EGO-IIP. Relevant DVH parameters (prostate-V100%, D90%, V150%; urethra-D(0.1cm3) and D(1.0cm3); rectum-D(0.1cm3) and D(2.0cm3); bladder-D(2.0cm3)) were evaluated and their compliance to the constraints. Treatment planning time was also recorded. All inverse methods resulted in shorter planning time (mean, 4-6.7 min), as compared with GrO (mean, 7.6 min). In terms of DVH parameters, none of the inverse methods outperformed the others. However, all inverse methods improved on compliance to the planning constraints as compared with GrO. On average, EGO-IIP and GrO resulted in highest D90%, and the IPSA plans resulted in lowest bladder D2.0cm3 and urethra D(1.0cm3). Inverse planning methods decrease planning time as compared with GrO for PDR/high-dose-rate prostate brachytherapy. DVH parameters are comparable for all methods. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  17. Single versus multichannel applicator in high-dose-rate vaginal brachytherapy optimized by inverse treatment planning.

    Science.gov (United States)

    Bahadur, Yasir A; Constantinescu, Camelia; Hassouna, Ashraf H; Eltaher, Maha M; Ghassal, Noor M; Awad, Nesreen A

    2015-01-01

    To retrospectively compare the potential dosimetric advantages of a multichannel vaginal applicator vs. a single channel one in intracavitary vaginal high-dose-rate (HDR) brachytherapy after hysterectomy, and evaluate the dosimetric advantage of fractional re-planning. We randomly selected 12 patients with endometrial carcinoma, who received adjuvant vaginal cuff HDR brachytherapy using a multichannel applicator. For each brachytherapy fraction, two inverse treatment plans (for central channel and multichannel loadings) were performed and compared. The advantage of fractional re-planning was also investigated. Dose-volume-histogram (DVH) analysis showed limited, but statistically significant difference (p = 0.007) regarding clinical-target-volume dose coverage between single and multichannel approaches. For the organs-at-risk rectum and bladder, the use of multichannel applicator demonstrated a noticeable dose reduction, when compared to single channel, but statistically significant for rectum only (p = 0.0001). For D2cc of rectum, an average fractional dose of 6.1 ± 0.7 Gy resulted for single channel vs. 5.1 ± 0.6 Gy for multichannel. For D2cc of bladder, an average fractional dose of 5 ± 0.9 Gy occurred for single channel vs. 4.9 ± 0.8 Gy for multichannel. The dosimetric benefit of fractional re-planning was demonstrated: DVH analysis showed large, but not statistically significant differences between first fraction plan and fractional re-planning, due to large inter-fraction variations for rectum and bladder positioning and filling. Vaginal HDR brachytherapy using a multichannel vaginal applicator and inverse planning provides dosimetric advantages over single channel cylinder, by reducing the dose to organs at risk without compromising the target volume coverage, but at the expense of an increased vaginal mucosa dose. Due to large inter-fraction dose variations, we recommend individual fraction treatment plan optimization.

  18. Recovery of hormone sensitivity after salvage brachytherapy for hormone refractory localized prostate cancer

    OpenAIRE

    Dan Smith; P. Nick Plowman

    2010-01-01

    PURPOSE: Recent work has demonstrated the return of hormone sensitivity after palliative chemotherapy in androgen independent prostate cancer. We wished to establish whether a similar phenomenon existed in patients with no exposure to chemotherapy. MATERIALS AND METHODS: A review of “hormone resistant” patients who had received salvage brachytherapy for localized prostate cancer after previous external beam radiotherapy was undertaken. Three patients with subsequent biochemical re...

  19. Salvage high-dose-rate interstitial brachytherapy for locally recurrent rectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pellizzon, Antonio Cassio Assis, E-mail: acapellizzon@hcancer.org.br [A.C. Camargo Cancer Center, Sao Paulo, SP (Brazil). Departamento de Radioterapia

    2016-05-15

    For tumors of the lower third of the rectum, the only safe surgical procedure is abdominal-perineal resection. High-dose-rate interstitial brachytherapy is a promising treatment for local recurrence of previously irradiated lower rectal cancer, due to the extremely high concentrated dose delivered to the tumor and the sparing of normal tissue, when compared with a course of external beam radiation therapy. (author)

  20. Long-term survival after intraluminal brachytherapy for inoperable hilar cholangiocarcinoma: A case report

    Institute of Scientific and Technical Information of China (English)

    Siu-Yin Chan; Ronnie T. Poon; Kelvin K. Ng; Chi-Leung Liu; Raymond T. Chan; Sheung-Tat Fan

    2005-01-01

    Surgical resection with a tumor-free margin is the onlycurative treatment for hilar cholangiocarcinoma (Klatskin tumor). However, over half of the patients present late with unresectable tumors. Radiotherapy using external beamirradiation or intraluminal brachytherapy (ILBT) has been used to treat unresectable hilar cholangiocarcinoma with satisfactory outcome. We reported a patient with unresectable hilar cholangiocarcinoma surviving more than 6 years after combined external beam irradiation and ILBT.

  1. A fully actuated robotic assistant for MRI-guided prostate biopsy and brachytherapy

    Science.gov (United States)

    Li, Gang; Su, Hao; Shang, Weijian; Tokuda, Junichi; Hata, Nobuhiko; Tempany, Clare M.; Fischer, Gregory S.

    2013-03-01

    Intra-operative medical imaging enables incorporation of human experience and intelligence in a controlled, closed-loop fashion. Magnetic resonance imaging (MRI) is an ideal modality for surgical guidance of diagnostic and therapeutic procedures, with its ability to perform high resolution, real-time, high soft tissue contrast imaging without ionizing radiation. However, for most current image-guided approaches only static pre-operative images are accessible for guidance, which are unable to provide updated information during a surgical procedure. The high magnetic field, electrical interference, and limited access of closed-bore MRI render great challenges to developing robotic systems that can perform inside a diagnostic high-field MRI while obtaining interactively updated MR images. To overcome these limitations, we are developing a piezoelectrically actuated robotic assistant for actuated percutaneous prostate interventions under real-time MRI guidance. Utilizing a modular design, the system enables coherent and straight forward workflow for various percutaneous interventions, including prostate biopsy sampling and brachytherapy seed placement, using various needle driver configurations. The unified workflow compromises: 1) system hardware and software initialization, 2) fiducial frame registration, 3) target selection and motion planning, 4) moving to the target and performing the intervention (e.g. taking a biopsy sample) under live imaging, and 5) visualization and verification. Phantom experiments of prostate biopsy and brachytherapy were executed under MRI-guidance to evaluate the feasibility of the workflow. The robot successfully performed fully actuated biopsy sampling and delivery of simulated brachytherapy seeds under live MR imaging, as well as precise delivery of a prostate brachytherapy seed distribution with an RMS accuracy of 0.98mm.

  2. Simulation of 3D Needle-Tissue Interaction with Application to Image Guided Prostate Brachytherapy

    Institute of Scientific and Technical Information of China (English)

    姜杉; HATA; Nobuhiko; 肖渤瀚; 安蔚瑾

    2010-01-01

    To improve global control of disease and reduce global toxicity, a complex seed distribution pattern should be achieved with great accuracy during brachytherapy.However, the interaction between the needle and prostate will cause large deformation of soft tissue.As a result, seeds will be misplaced, sharp demarcation between irradiated volume and healthy structures is unavailable and this will cause side effects such as impotence and urinary incontinence.In this paper, a 3D nonlinear dynamic finite element s...

  3. Portfolio of prospective clinical trials including brachytherapy: an analysis of the ClinicalTrials.gov database

    OpenAIRE

    Cihoric, Nikola; Tsikkinis, Alexandros; Miguelez, Cristina Gutierrez; Strnad, Vratislav; Soldatovic, Ivan; Ghadjar, Pirus; Jeremic, Branislav; Dal Pra, Alan; Aebersold, Daniel M; Lössl, Kristina

    2016-01-01

    Background To evaluate the current status of prospective interventional clinical trials that includes brachytherapy (BT) procedures. Methods The records of 175,538 (100 %) clinical trials registered at ClinicalTrials.gov were downloaded on September 2014 and a database was established. Trials using BT as an intervention were identified for further analyses. The selected trials were manually categorized according to indication(s), BT source, applied dose rate, primary sponsor type, location, p...

  4. Portfolio of prospective clinical trials including brachytherapy: an analysis of the ClinicalTrials.gov database

    OpenAIRE

    Cihoric, Nikola; Tsikkinis, Alexandros; Gutierrez Miguelez, Cristina; Strnad, Vratislav; Soldatovic, Ivan; Ghadjar, Pirus; Jeremic, Branislav; Dal Pra, Alan; Aebersold, Daniel M; Lössl, Kristina

    2016-01-01

    Background To evaluate the current status of prospective interventional clinical trials that includes brachytherapy (BT) procedures. Methods The records of 175,538 (100 %) clinical trials registered at ClinicalTrials.gov were downloaded on September 2014 and a database was established. Trials using BT as an intervention were identified for further analyses. The selected trials were manually categorized according to indication(s), BT source, applied dose rate, primary sponsor type,...

  5. The Effects of Metallic Implants on Electroporation Therapies: Feasibility of Irreversible Electroporation for Brachytherapy Salvage

    Energy Technology Data Exchange (ETDEWEB)

    Neal, Robert E., E-mail: robert.neal@alfred.org.au [The Alfred Hospital, Radiology Research Unit, Department of Radiology (Australia); Smith, Ryan L., E-mail: ryan.smith@wbrc.org.au [The Alfred Hospital, William Buckland Radiotherapy Centre (Australia); Kavnoudias, Helen, E-mail: H.Kavnoudias@alfred.org.au [The Alfred Hospital, Radiology Research Unit, Department of Radiology (Australia); Rosenfeldt, Franklin, E-mail: F.Rosenfeldt@alfred.org.au; Ou, Ruchong, E-mail: Ruchong.Ou@bakeridi.edu.au [Monash University, Department of Surgery (Australia); Mclean, Catriona A., E-mail: C.Mclean@alfred.org.au [The Alfred Hospital, Department of Anatomical Pathology (Australia); Davalos, Rafael V., E-mail: davalos@vt.edu [Virginia Tech, School of Biomedical Engineering and Sciences (United States); Thomson, Kenneth R., E-mail: K.Thomson@alfred.org.au [The Alfred Hospital, Radiology Research Unit, Department of Radiology (Australia)

    2013-12-15

    Purpose: Electroporation-based therapies deliver brief electric pulses into a targeted volume to destabilize cellular membranes. Nonthermal irreversible electroporation (IRE) provides focal ablation with effects dependent on the electric field distribution, which changes in heterogeneous environments. It should be determined if highly conductive metallic implants in targeted regions, such as radiotherapy brachytherapy seeds in prostate tissue, will alter treatment outcomes. Theoretical and experimental models determine the impact of prostate brachytherapy seeds on IRE treatments. Materials and Methods: This study delivered IRE pulses in nonanimal, as well as in ex vivo and in vivo tissue, with and in the absence of expired radiotherapy seeds. Electrical current was measured and lesion dimensions were examined macroscopically and with magnetic resonance imaging. Finite-element treatment simulations predicted the effects of brachytherapy seeds in the targeted region on electrical current, electric field, and temperature distributions. Results: There was no significant difference in electrical behavior in tissue containing a grid of expired radiotherapy seeds relative to those without seeds for nonanimal, ex vivo, and in vivo experiments (all p > 0.1). Numerical simulations predict no significant alteration of electric field or thermal effects (all p > 0.1). Histology showed cellular necrosis in the region near the electrodes and seeds within the ablation region; however, there were no seeds beyond the ablation margins. Conclusion: This study suggests that electroporation therapies can be implemented in regions containing small metallic implants without significant changes to electrical and thermal effects relative to use in tissue without the implants. This supports the ability to use IRE as a salvage therapy option for brachytherapy.

  6. Salvage high-dose-rate interstitial brachytherapy for locally recurrent rectal cancer*

    Science.gov (United States)

    Pellizzon, Antônio Cássio Assis

    2016-01-01

    For tumors of the lower third of the rectum, the only safe surgical procedure is abdominal-perineal resection. High-dose-rate interstitial brachytherapy is a promising treatment for local recurrence of previously irradiated lower rectal cancer, due to the extremely high concentrated dose delivered to the tumor and the sparing of normal tissue, when compared with a course of external beam radiation therapy. PMID:27403021

  7. A real-time applicator position monitoring system for gynecologic intracavitary brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Junyi, E-mail: junyi-xia@uiowa.edu; Waldron, Timothy; Kim, Yusung [Department of Radiation Oncology, University of Iowa, Iowa City, Iowa 52242 (United States)

    2014-01-15

    Purpose: To develop a real-time applicator position monitoring system (RAPS) for intracavitary brachytherapy using an infrared camera and reflective markers. Methods: 3D image-guided brachytherapy requires high accuracy of applicator localization; however, applicator displacement can happen during patient transfer for imaging and treatment delivery. No continuous applicator position monitoring system is currently available. The RAPS system was developed for real-time applicator position monitoring without additional radiation dose to patients. It includes an infrared camera, reflective markers, an infrared illuminator, and image processing software. After reflective markers are firmly attached to the applicator and the patient body, applicator displacement can be measured by computing the relative change in distance between the markers. The reflective markers are magnetic resonance imaging (MRI) compatible, which is suitable for MRI-guided HDR brachytherapy paradigm. In our prototype, a Microsoft Kinect sensor with a resolution of 640 by 480 pixels is used as an infrared camera. A phantom study was carried out to compare RAPS' measurements with known displacements ranging from −15 to +15 mm. A reproducibility test was also conducted. Results: The RAPS can achieve 4 frames/s using a laptop with Intel{sup ®} Core™2 Duo processor. When the pixel size is 0.95 mm, the difference between RAPS' measurements and known shift values varied from 0 to 0.8 mm with the mean value of 0.1 mm and a standard deviation of 0.44 mm. The system reproducibility was within 0.6 mm after ten reposition trials. Conclusions: This work demonstrates the feasibility of a real-time infrared camera based gynecologic intracavitary brachytherapy applicator monitoring system. Less than 1 mm accuracy is achieved when using an off-the-shelf infrared camera.

  8. Effect of tissue composition on dose distribution in brachytherapy with various photon emitting sources

    Science.gov (United States)

    Ghorbani, Mahdi; Salahshour, Fateme; Haghparast, Abbas; Knaup, Courtney

    2014-01-01

    Purpose The aim of this study is to compare the dose in various soft tissues in brachytherapy with photon emitting sources. Material and methods 103Pd, 125I, 169Yb, 192Ir brachytherapy sources were simulated with MCNPX Monte Carlo code, and their dose rate constant and radial dose function were compared with the published data. A spherical phantom with 50 cm radius was simulated and the dose at various radial distances in adipose tissue, breast tissue, 4-component soft tissue, brain (grey/white matter), muscle (skeletal), lung tissue, blood (whole), 9-component soft tissue, and water were calculated. The absolute dose and relative dose difference with respect to 9-component soft tissue was obtained for various materials, sources, and distances. Results There was good agreement between the dosimetric parameters of the sources and the published data. Adipose tissue, breast tissue, 4-component soft tissue, and water showed the greatest difference in dose relative to the dose to the 9-component soft tissue. The other soft tissues showed lower dose differences. The dose difference was also higher for 103Pd source than for 125I, 169Yb, and 192Ir sources. Furthermore, greater distances from the source had higher relative dose differences and the effect can be justified due to the change in photon spectrum (softening or hardening) as photons traverse the phantom material. Conclusions The ignorance of soft tissue characteristics (density, composition, etc.) by treatment planning systems incorporates a significant error in dose delivery to the patient in brachytherapy with photon sources. The error depends on the type of soft tissue, brachytherapy source, as well as the distance from the source. PMID:24790623

  9. Current topics in the treatment of prostate cancer with low-dose-rate brachytherapy.

    Science.gov (United States)

    Stock, Richard G; Stone, Nelson N

    2010-02-01

    The treatment of prostate cancer with low dose rate prostate brachytherapy has grown rapidly in the last 20 years. Outcome analyses performed in this period have enriched understanding of this modality. This article focuses on the development of a real-time ultrasound-guided implant technique, the importance of radiation dose, trimodality treatment of high-risk disease, long-term treatment outcomes, and treatment-associated morbidity.

  10. Adjuvant brachytherapy for endometrial cancer: advantages of the vaginal mold technique.

    Science.gov (United States)

    El Khoury, Clement; Dumas, Isabelle; Tailleur, Anne; Morice, Philippe; Haie-Meder, Christine

    2015-01-01

    Treatment of endometrial carcinoma in the adjuvant setting includes in most cases vaginal brachytherapy. In our institution, we use the customized vaginal mold technique. Herein, we report the advantages of this personalized applicator in terms of target coverage, normal tissue preservation, the incidence of air pockets, and its potential impact on dosimetry. A total of 15 patients receiving postoperative vaginal cuff high-dose-rate brachytherapy with the mold applicator technique were enrolled in this prospective data collection study. Patients were treated with either two or four fractions of 5 Gy prescribed to the clinical target volume, which consisted of an irradiation of the vaginal cuff and the upper third of the vagina. Target coverage; dose to organs at risk, in addition to the volume; and the dosimetric impact of air pockets surrounding the mold were evaluated. In 15 patients, a total of 27 air pockets were identified. The average number of air pockets per patient was 1.8 (range, 0-4), with the average total air pocket volume being 0.1 cc (range, 0.01-0.54). The average dose reduction at 5mm from the air pocket was 26% (range, 6-45%). The minimal clinical target volume coverage reported was 95% and the maximal dose received by 2 cc of the bladder, rectum, and sigmoid never exceeded 110% of the prescribed dose. Vaginal cuff high-dose-rate brachytherapy using the molded applicator provides personalized tailored treatment in terms of anatomical conformity. This translates into a dosimetrical advantage with smaller and fewer air pockets than reported in the literature with the use of cylinders. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  11. Pudendal nerve block in HDR-brachytherapy patients: do we really need general or regional anesthesia?

    Science.gov (United States)

    Schenck, Marcus; Schenck, Catarina; Rübben, Herbert; Stuschke, Martin; Schneider, Tim; Eisenhardt, Andreas; Rossi, Roberto

    2013-04-01

    In male patients, the pudendal block was applied only in rare cases as a therapy of neuralgia of the pudendal nerve. We compared pudendal nerve block (NPB) and combined spinal-epidural anesthesia (CSE) in order to perform a pain-free high-dose-rate (HDR) brachytherapy in a former pilot study in 2010. Regarding this background, in the present study, we only performed the bilateral perineal infiltration of the pudendal nerve. In 25 patients (71.8 ± 4.18 years) suffering from a high-risk prostate carcinoma, we performed the HDR-brachytherapy with the NPB. The perioperative compatibility, the subjective feeling (German school marks principle 1-6), subjective pain (VAS 1-10) and the early postoperative course (mobility, complications) were examined. All patients preferred the NPB. There was no change of anesthesia form necessary. The expense time of NPB was 10.68 ± 2.34 min. The hollow needles (mean 24, range 13-27) for the HDR-brachytherapy remained on average 79.92 ± 12.41 min. During and postoperative, pain feeling was between 1.4 ± 1.08 and 1.08 ± 1.00. A transurethral 22 French Foley catheter was left in place for 6 h. All patients felt the bladder catheter as annoying, but they considered postoperative mobility as more important as complete lack of pain. The subjective feeling was described as 2.28 ± 0.74. Any side effects or complications did not appear. Bilateral NPB is a safe and effective analgesic option in HDR-brachytherapy and can replace CSE. It offers the advantage of almost no impaired mobility of the patient and can be performed by the urologist himself. Using transrectal ultrasound guidance, the method can be learned quickly.

  12. Perioperative high-dose-rate brachytherapy in the treatment of recurrent malignant gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Fabrini, Maria Grazia; Pasqualetti, Francesco; Grespi, Silvia [Div. of Radiation Oncology, ' ' S. Chiara' ' Pisa Hospital (Italy); Perrone, Franco [Div. of Health Physics, ' ' S. Chiara' ' Pisa Hospital (Italy); De Franco, Lucia; Vannozzi, Riccardo [Div. of Neurosurgery, ' ' S. Chiara' ' Pisa Hospital (Italy); Cionini, Luca [Div. of Radiation Oncology, ' ' S. Chiara' ' Pisa Hospital (Italy); Pisa Univ. (Italy)

    2009-08-15

    Purpose: To assess the feasibility and effectiveness of perioperative high-dose-rate brachytherapy for recurrent malignant gliomas. Patients and Methods: Between 2005 and 2008, 21 patients (14 males and seven females) with relapsed malignant glioma underwent a second surgery followed by a brachytherapy implant in the surgical cavity. Median age was 60 years, and median Karnofsky performance status 80. A single fraction of 18 Gy specified at 5 mm depth was administered perioperatively. Then, the applicator was removed nonsurgically. Mean postoperative hospitalization time was 3 days. Results: At the time of analysis, 15 patients (71%) had died and six (29%) were alive. Median follow-up was 32.3 months. Median overall survival from diagnosis amounted to 21.7 months. Median survival after recurrence was 8.0 months, and 6-month progression-free survival 42%. Patients were stratified into classes according to the prognostic recursive partitioning analysis. Conclusion: Perioperative brachytherapy has proven to be safe and well tolerated in patients with recurrent malignant glioma. No severe toxicity was reported, and the treatment has proven to be effective in symptomatic recurrences of malignant gliomas. (orig.)

  13. Radiation therapy for localized prostate cancer. For high-dose rate conformal brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kinugawa, Keigo; Jo, Yoshimasa; Morioka, Masaaki; Tanaka, Hiroyoshi; Hiratsuka, Junichi; Imajo, Yoshinari [Kawasaki Medical School, Kurashiki, Okayama (Japan)

    1999-05-01

    Sixteen patients with localized prostate cancer were referred to our clinic for radiation therapy in combination with HDR brachytherapy using Ir-192 pellets between October 1997 and August 1998. The patients were given external beam radiation of 45 Gy to the whole pelvis in combination with an interstitial HDR brachytherapy implant of 3 fractions each delivering 5.5 Gy during two days. Using an implanting device especially designed for HDR, 10-18 applicator needles (17 gauge) were implanted into the prostate using transrectal ultrasound (TRUS) with perineal template guidance under spinal anesthesia. Pathological evaluation was performed at 6 months after treatment. This technique of external beam radiation combined with HDR brachytherapy was well tolerated. Serum prostatic antigen (PSA) levels became normalized in 87.5% of the patients (14 out of 16) within 1-14 months (median 2 months) after the irradiation. No significant intraoperative or perioperative complications occurred, however one patient (6.25%) experienced Grade 3 hematuria. Most of the early complications were otherwise Grade 1 or 2. From prospectively planned prostatic rebiopsies performed at 6 months, we can observe the radiation effects in the pathological findings such as fibrosis, basal cell hyperplasia, bizarre cells and intraductal calcifications. (K.H.)

  14. Clinical outcome of high-dose-rate interstitial brachytherapy in patients with oral cavity cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Uk; Cho, Kwan Ho; Moon, Sung Ho; Choi, Sung Weon; Park, Joo Yong; Yun, Tak; Lee, Sang Hyun; Lim, Young Kyung; Jeong, Chi Young [National Cancer Center, Goyang (Korea, Republic of)

    2014-12-15

    To evaluate the clinical outcome of high-dose-rate (HDR) interstitial brachytherapy (IBT) in patients with oral cavity cancer. Sixteen patients with oral cavity cancer treated with HDR remote-control afterloading brachytherapy using 192Ir between 2001 and 2013 were analyzed retrospectively. Brachytherapy was administered in 11 patients as the primary treatment and in five patients as salvage treatment for recurrence after the initial surgery. In 12 patients, external beam radiotherapy (50-55 Gy/25 fractions) was combined with IBT of 21 Gy/7 fractions. In addition, IBT was administered as the sole treatment in three patients with a total dose of 50 Gy/10 fractions and as postoperative adjuvant treatment in one patient with a total of 35 Gy/7 fractions. The 5-year overall survival of the entire group was 70%. The actuarial local control rate after 3 years was 84%. All five recurrent cases after initial surgery were successfully salvaged using IBT +/- external beam radiotherapy. Two patients developed local recurrence at 3 and 5 months, respectively, after IBT. The acute complications were acceptable (< or =grade 2). Three patients developed major late complications, such as radio-osteonecrosis, in which one patient was treated by conservative therapy and two required surgical intervention. HDR IBT for oral cavity cancer was effective and acceptable in diverse clinical settings, such as in the cases of primary or salvage treatment.

  15. Head and neck (192)Ir HDR-brachytherapy dosimetry using a grid-based Boltzmann solver.

    Science.gov (United States)

    Siebert, Frank-André; Wolf, Sabine; Kóvacs, George

    2013-12-01

    To compare dosimetry for head and neck cancer patients, calculated with TG-43 formalism and a commercially available grid-based Boltzmann solver. This study included 3D-dosimetry of 49 consecutive brachytherapy head and neck cancer patients, computed by a grid-based Boltzmann solver that takes into account tissue inhomogeneities as well as TG-43 formalism. 3D-treatment planning was carried out by using computed tomography. Dosimetric indices D90 and V100 for target volume were about 3% lower (median value) for the grid-based Boltzmann solver relative to TG-43-based computation (p Boltzmann solver to TG-43 (p Boltzmann solver and TG-43 formalism for high-dose-rate head and neck brachytherapy patients to the target volume were found. Distinctions in D90 of CTV were low (2.63 Gy for grid-based Boltzmann solver vs. 2.71 Gy TG-43 in mean). In our clinical practice, prescription doses remain unchanged for high-dose-rate head and neck brachytherapy for the time being.

  16. Evaluation of sexual functions and sexual behaviors after penile brachytherapy in men treated for penile carcinoma.

    Science.gov (United States)

    Soh, Patrice Njomnang; Delaunay, Boris; Nasr, Elie Bou; Delannes, Martine; Soulie, Michel; Huyghe, Eric

    2014-01-01

    To assess sexual functions and behaviors of men treated by penile brachytherapy for a cancer of the penis. Thirty eight men (19 patients treated by penile brachytherapy for a cancer of the penis and 19 age paired-matched controls) participated in a survey about sexuality. The mean age of patients and controls were 73.2 +/- 11.7 and 70.0 +/- 10.5 years, respectively (NS). Controls were men without penile pathology, without history of cancer and no evidence of cognitive impairment. All agreed to participate in the survey about sexuality using 2 questionnaires : the IIEF questionnaire, which explores 4 domains of sexual functions, namely erection, satisfaction, orgasm and desire, and a questionnaire created using the BASIC IDEA grid, which addresses nine domains: behavior, affect, sensation, self-image, cognition, interpersonal, drugs, expectation and attitude. Patients had better scores than controls in 3 domains of the IIEF: erection, desire and satisfaction. These results contrasted with the frequency of intercourse and the quality of erection (evaluated through the BASIC IDEA questionnaire) that were not significantly different between the two populations. Patients also had significantly higher frequency of masturbation (p sexual performance and higher expected satisfaction for future life (p: 0.021) than controls. Penile brachytherapy is a treatment of cancer of the penis that seems to have a moderated impact on sexual functions since most of sexual scores are not inferior in these patients than in age pair-matched controls.

  17. Comparison Analysis of MR Images Before and After External Beam Radiotherapy in Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eun Hye; Baek, Chung Seok; Lee, Sung Yong; Byun, Young Sik [Dept. of Radiation Oncology, Cheil General Hospital, Seoul (Korea, Republic of)

    2011-03-15

    To analyze availability of MR images before and after external beam radiotherapy in brachytherapy, we will acquire MR images before and after external beam radiotherapy and compare the change of direction of uterine cavity and analyze the accuracy of applicator insertion. From January 2009 to December 2010, we compared MR images before and after external beam radiotherapy for uterine cervical cancer only with radical purpose treatment. MR images which was acquired after external beam radiotherapy has done with inserted status of CT/MR applicator. As a consequence, the tumor was markedly reduced after external beam radiotherapy. The change of anteflexion of uterus turned into retroflexion of the uterine cavity was 17.1%. The case of wrong insertion of tandem include direction or length was 14.3%. According to MR images taken after external beam radiotherapy, we recognized not only reduced the tumor volume but the marked change of exact direction or length of the uterine cavity. So the confirmation of accurate insertion based on MR images before brachytherapy could be very helpful for optimal brachytherapy treatment planning with reduced applicator insertion errors.

  18. Quality control of the breast cancer treatments on Hdr brachytherapy with TLD-100

    Energy Technology Data Exchange (ETDEWEB)

    Torres H, F. [Universidad de Cordoba, Materials and Applied Physics Group, 230002 Monteria, Cordoba (Colombia); De la Espriella V, N. [Universidad de Cordoba, Grupo Avanzado de Materiales y Sistemas Complejos, 230002 Monteria, Cordoba (Colombia); Sanchez C, A., E-mail: franciscotorreshoyos@yahoo.com [Universidad de Cordoba, Departamento de Enfermeria, 230002 Monteria, Cordoba (Colombia)

    2014-07-01

    An anthropomorphic Phantom, a female trunk, was built with a natural bone structure and experimental material coated, glycerin and water-based material called JJT to build soft tissue equivalent to the muscle of human tissue, and a polymer (styrofoam) to build the lung as critical organ to simulate the treatment of breast cancer, with high dose rate brachytherapy (Hdr) and sources of Ir-192. The treatments were planned and calculated for the critical organ: Lung, and injury of 2 cm in diameter in breast with Micro Selectron Hdr system and the software Plato Brachytherapy V 14.1 of the Nucletron (Netherlands) which uses the standard protocol of radiotherapy for brachytherapy treatments. The dose experimentally measured with dosimeters TLD-100 LiF: Mg; Ti, which were previously calibrated, were placed in the same positions and bodies mentioned above, with less than 5% uncertainty. The reading dosimeters was carried out in a Harshaw TLD 4500. The results obtained for calculated treatments, using the standard simulator, and the experimental with TLD-100, show a high concordance, as they are on average a ± 1.1% making process becomes in a quality control of this type of treatments. (Author)

  19. Optical fibre luminescence sensor for real-time LDR brachytherapy dosimetry

    Science.gov (United States)

    Woulfe, P.; Sullivan, F. J.; O'Keeffe, S.

    2016-05-01

    An optical fibre sensor for monitoring low dose radiation is presented. The sensor is based on a scintillation material embedded within the optical fibre core, which emits visible light when exposed to low level ionising radiation. The incident level of ionising radiation can be determined by analysing the optical emission. An optical fibre sensor is presented, based on radioluminescence whereby radiation sensitive scintillation material, terbium doped gadolinium oxysulphide (Gd2O2S:Tb), is embedded in a cavity of 250μm of a 500μm plastic optical fibre. The sensor is designed for in-vivo monitoring of the radiation dose during radio-active seed implantation for brachytherapy, in prostate cancer treatment, providing oncologists with real-time information of the radiation dose to the target area and/or nearby critical structures. The radiation from the brachytherapy seeds causes emission of visible light from the scintillation material through the process of radioluminescence, which penetrates the fibre, propagating along the optical fibre for remote detection using a multi-pixel photon counter. The sensor demonstrates a high sensitivity to Iodine-125, the radioactive source most commonly used in brachytherapy for treating prostate cancer.

  20. Pulsed dose rate brachytherapy (PDR): an analysis of the technique at 2 years

    Energy Technology Data Exchange (ETDEWEB)

    Thienpont, M. [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde; Van Eijkeren, M.; Van Hecke, H.; Boterberg, T.; De Neve, W.

    1995-12-01

    A total of 154 applications was analysed using a pulsed dose brachytherapy technique for 138 patients over a 2 year period with emphasis on technical aspects influencing the overall treatment time. Vaginal ovoids were used in 59 cases, plastic tubes in 52, a Fletcher-type in 18, vaginal cylinders in 14 and a perineal template in 11 cases. Pulses were given at hourly intervals with a median dose rate of 0.6 Gy per pulse (range 0.4 to 3 Gy). The number of pulses per application varied from 3 to 134 (median 32). The number of dwell positions varied from 1 to 542 over 1 to 18 catheters. Patient related problems were few. The room was entered almost every 77 minutes. We noted 561 status codes in 147 applications. Of the 25 different codes, the most frequent one was due to the door left open when a pulse had to be given (35%) or due to constriction of the plastic catheters at the transfer tube junction (26%). However, the median total treatment time was increased by only 5 minutes. With pulsed dose rate brachytherapy at hourly pulses we can treat our patients within the planned time despite frequent room entrance and occurrence of an appreciable number of status codes. This technique seems to fulfill its promise to replace low dose rate brachytherapy.

  1. Variability of marker-based rectal dose evaluation in HDR cervical brachytherapy.

    Science.gov (United States)

    Wang, Zhou; Jaggernauth, Wainwright; Malhotra, Harish K; Podgorsak, Matthew B

    2010-01-01

    In film-based intracavitary brachytherapy for cervical cancer, position of the rectal markers may not accurately represent the anterior rectal wall. This study was aimed at analyzing the variability of rectal dose estimation as a result of interfractional variation of marker placement. A cohort of five patients treated with multiple-fraction tandem and ovoid high-dose-rate (HDR) brachytherapy was studied. The cervical os point and the orientation of the applicators were matched among all fractional plans for each patient. Rectal points obtained from all fractions were then input into each clinical treated plan. New fractional rectal doses were obtained and a new cumulative rectal dose for each patient was calculated. The maximum interfractional variation of distances between rectal dose points and the closest source positions was 1.1 cm. The corresponding maximum variability of fractional rectal dose was 65.5%. The percentage difference in cumulative rectal dose estimation for each patient was 5.4%, 19.6%, 34.6%, 23.4%, and 13.9%, respectively. In conclusion, care should be taken when using rectal markers as reference points for estimating rectal dose in HDR cervical brachytherapy. The best estimate of true rectal dose for each fraction should be determined by the most anterior point among all fractions.

  2. Recovery of hormone sensitivity after salvage brachytherapy for hormone refractory localized prostate cancer

    Directory of Open Access Journals (Sweden)

    Dan Smith

    2010-06-01

    Full Text Available PURPOSE: Recent work has demonstrated the return of hormone sensitivity after palliative chemotherapy in androgen independent prostate cancer. We wished to establish whether a similar phenomenon existed in patients with no exposure to chemotherapy. MATERIALS AND METHODS: A review of “hormone resistant” patients who had received salvage brachytherapy for localized prostate cancer after previous external beam radiotherapy was undertaken. Three patients with subsequent biochemical relapse responded to the rechallenge with hormonal treatment. RESULTS: The series of patients presented here demonstrates this phenomenon occurs after salvage brachytherapy with no exposure to chemotherapy. Recovery of sensitivity is demonstrated both to androgen deprivation and to androgen receptor antagonism. The recovery of hormone sensitivity was surprisingly durable, ranging from eight months to over twenty-one months. CONCLUSIONS: Hormone sensitivity may be recovered after salvage brachytherapy. Potential mechanisms underlying these observations are discussed and the likely central role of the activity of the androgen receptor highlighted. The relevance of these findings to the management of advanced prostate cancer is considered including thoughts on the practice of intermittent anti-androgen therapy.

  3. 3D-printed applicators for high dose rate brachytherapy: Dosimetric assessment at different infill percentage.

    Science.gov (United States)

    Ricotti, Rosalinda; Vavassori, Andrea; Bazani, Alessia; Ciardo, Delia; Pansini, Floriana; Spoto, Ruggero; Sammarco, Vittorio; Cattani, Federica; Baroni, Guido; Orecchia, Roberto; Jereczek-Fossa, Barbara Alicja

    2016-12-01

    Dosimetric assessment of high dose rate (HDR) brachytherapy applicators, printed in 3D with acrylonitrile butadiene styrene (ABS) at different infill percentage. A low-cost, desktop, 3D printer (Hamlet 3DX100, Hamlet, Dublin, IE) was used for manufacturing simple HDR applicators, reproducing typical geometries in brachytherapy: cylindrical (common in vaginal treatment) and flat configurations (generally used to treat superficial lesions). Printer accuracy was investigated through physical measurements. The dosimetric consequences of varying the applicator's density by tuning the printing infill percentage were analysed experimentally by measuring depth dose profiles and superficial dose distribution with Gafchromic EBT3 films (International Specialty Products, Wayne, NJ). Dose distributions were compared to those obtained with a commercial superficial applicator. Measured printing accuracy was within 0.5mm. Dose attenuation was not sensitive to the density of the material. Surface dose distribution comparison of the 3D printed flat applicators with respect to the commercial superficial applicator showed an overall passing rate greater than 94% for gamma analysis with 3% dose difference criteria, 3mm distance-to-agreement criteria and 10% dose threshold. Low-cost 3D printers are a promising solution for the customization of the HDR brachytherapy applicators. However, further assessment of 3D printing techniques and regulatory materials approval are required for clinical application. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  4. Deformable anatomical templates for brachytherapy treatment planning in radiotherapy of cervical cancer

    Science.gov (United States)

    Christensen, Gary E.; Williamson, Jeffrey F.; Chao, K. S. C.; Miller, Michael I.; So, F. B.; Vannier, Michael W.

    1997-10-01

    This paper describes a new method to register serial, volumetric x-ray computed tomography (CT) data sets for tracking soft-tissue deformation caused by insertion of intracavity brachytherapy applicators to treat cervical cancer. 3D CT scans collected from the same patient with and without a brachytherapy applicator are registered to aid in computation of the radiation dose to tumor and normal tissue. The 3D CT image volume of pelvic anatomy with the applicator. Initial registration is accomplished by rigid alignment of the pelvic bones and non-rigid alignment of gray scale CT data and hand segmentations of the vagina, cervix, bladder, and rectum. A viscous fluid transformation model is used for non-rigid registration to allow for local, non-linear registration of the vagina, cervix, bladder, and rectum without disturbing the rigid registration of the bony pelvis and adjacent structures. Results are presented in which two 3D CT data sets of the same patient - imaged with and without a brachytherapy applicator - are registered.

  5. [Risk factors of late complications after interstitial 192Ir brachytherapy in cancers of the oral cavity].

    Science.gov (United States)

    Peiffert, D

    1997-01-01

    Brachytherapy has confirmed its prevailing role in conservative treatment of oral cavity carcinomas. To describe late toxicity in long-term surviving patients, comparisons with other series are necessary. Study of series of patients implanted for floor of the mouth or mobile tongue shows the need for more detailed data. Dental prophylaxy and lead protection of the mandibule, good indications and techniques of brachytherapy are necessary to avoid late complications. Some treatment factors have proved to be of good prognosis for late complications through multivariate analysis of large series treated with lr 192 wires, using the Paris system, eg, dose rate lower than 0.5 or 0.7 Gy/h, intersource spacing smaller than 1.2 or 1.5 cm, treated surface less than 12 cm2, lineic activity less than 1.5 mCi/cm, less than 1 cm diameter hyperdose, and use of mandibular lead protections. Tumor volume and location to the floor of mouth lead to higher risk of complications. Knowledge of treatment-related factors is important, with the development of new afterloading projectors allowing to control the dose rate and correct small inhomogeneities. High-dose rate exclusive brachytherapy is not recommended. More precise and reproducible classification should be used to report complications in series leading to publications in the future, thus allowing to compare results, reduce complication rates and improve the quality of life.

  6. Differential dose contributions on total dose distribution of (125)I brachytherapy source.

    Science.gov (United States)

    Camgöz, B; Yeğin, G; Kumru, M N

    2010-01-01

    This work provides an improvement of the approach using Monte Carlo simulation for the Amersham Model 6711 (125)I brachytherapy seed source, which is well known by many theoretical and experimental studies. The source which has simple geometry was researched with respect to criteria of AAPM Tg-43 Report. The approach offered by this study involves determination of differential dose contributions that come from virtual partitions of a massive radioactive element of the studied source to a total dose at analytical calculation point. Some brachytherapy seeds contain multi-radioactive elements so the dose at any point is a total of separate doses from each element. It is momentous to know well the angular and radial dose distributions around the source that is located in cancerous tissue for clinical treatments. Interior geometry of a source is effective on dose characteristics of a distribution. Dose information of inner geometrical structure of a brachytherapy source cannot be acquired by experimental methods because of limits of physical material and geometry in the healthy tissue, so Monte Carlo simulation is a required approach of the study. EGSnrc Monte Carlo simulation software was used. In the design of a simulation, the radioactive source was divided into 10 rings, partitioned but not separate from each other. All differential sources were simulated for dose calculation, and the shape of dose distribution was determined comparatively distribution of a single-complete source. In this work anisotropy function was examined also mathematically.

  7. EVALUATION OF BRACHYTHERAPY FACILITY SHIELDING STATUS IN KOREA OBTAINED FROM RADIATION SAFETY REPORTS

    Directory of Open Access Journals (Sweden)

    MI HYUN KEUM

    2013-10-01

    Full Text Available Thirty-eight radiation safety reports for brachytherapy equipment were evaluated to determine the current status of brachytherapy units in Korea and to assess how radiation oncology departments in Korea complete radiation safety reports. The following data was collected: radiation safety report publication year, brachytherapy unit manufacturer, type and activity of the source that was used, affiliation of the drafter, exposure rate constant, the treatment time used to calculate workload and the HVL values used to calculate shielding design goal values. A significant number of the reports (47.4% included the personal information of the drafter. The treatment time estimates varied widely from 12 to 2,400 min/week. There was acceptable variation in the exposure rate constant values (ranging between 0.469 and 0.592 (R-m2/Ci·hr, as well as in the HVLs of concrete, steel and lead for Iridium-192 sources that were used to calculate shielding design goal values. There is a need for standard guidelines for completing radiation safety reports that realistically reflect the current clinical situation of radiation oncology departments in Korea. The present study may be useful for formulating these guidelines.

  8. Accelerated partial breast irradiation with brachytherapy: patient selection and technique considerations

    Directory of Open Access Journals (Sweden)

    Trifiletti DM

    2015-07-01

    Full Text Available Daniel M Trifiletti,1 Kara D Romano,1 Shayna L Showalter,2 Kelli A Reardon,1 Bruce Libby,1 Timothy N Showalter11Department of Radiation Oncology, 2Division of Surgical Oncology, Department of Surgery, University of Virginia School of Medicine, Charlottesville, VA, USAAbstract: Accelerated partial breast irradiation (APBI through breast brachytherapy is a relatively recent development in breast radiotherapy that has gained international favor because of its reduction in treatment duration and normal tissue irradiation while maintaining favorable cancer-specific and cosmetic outcomes. Despite the fact that several large national trials have not reported final results yet, many providers are currently offering APBI to select patients and APBI is listed as a treatment option for selecting patients in the National Comprehensive Cancer Network guidelines. Multiple consensus guidelines exist in selecting patients for APBI, some with conflicting recommendations. In this review, the existing patient selection guidelines are reported, compared, and critiqued, grouping them in helpful subcategories. Unique patient and technical selection factors for APBI with brachytherapy are explored.Keywords: breast cancer, APBI, breast brachytherapy

  9. Accuracy of needle implantation in brachytherapy using a medical AR system: a phantom study

    Science.gov (United States)

    Wesarg, Stefan; Firle, Evelyn A.; Schwald, Bernd; Seibert, Helmut; Zogal, Pawel; Roeddiger, Sandra

    2004-05-01

    Brachytherapy is the treatment method of choice for patients with a tumor relapse after a radiation therapy with external beams or tumors in regions with sensitive surrounding organs-at-risk, e. g. prostate tumors. The standard needle implantation procedure in brachytherapy uses pre-operatively acquired image data displayed as slices on a monitor beneath the operation table. Since this information allows only a rough orientation for the surgeon, the position of the needles has to be verified repeatedly during the intervention. Within the project Medarpa a transparent display being the core component of a medical Augmented Reality (AR) system has been developed. There, pre-operatively acquired image data is displayed together with the position of the tracked instrument allowing a navigated implantation of the brachytherapy needles. The surgeon is enabled to see the anatomical information as well as the virtual instrument in front of the operation area. Thus, the Medarpa system serves as "window into the patient". This paper deals with the results of first clinical trials of the system. Phantoms have been used for evaluating the achieved accuracy of the needle implantation. This has been done by comparing the output of the system (instrument positions relative to the phantom) with the real positions of the needles measured by means of a verification CT scan.

  10. Reirradiation for recurrent head and neck cancer with salvage interstitial pulsed-dose-rate brachytherapy. Long-term results

    Energy Technology Data Exchange (ETDEWEB)

    Strnad, Vratislav; Lotter, Michael; Kreppner, Stephan; Fietkau, Rainer [University Hospital Erlangen, Dept. of Radiation Oncology, Erlangen (Germany)

    2015-01-10

    To assess the long-term results of protocol-based interstitial pulsed-dose-rate (PDR) brachytherapy as reirradiation combined with simultaneous chemotherapy and interstitial hyperthermia in selected patients with recurrent head and neck tumors. A total of 104 patients with biopsy-proven recurrent head and neck cancer were treated with interstitial PDR brachytherapy. Salvage surgery had also been undergone by 53/104 (51 %) patients (R1 or R2 resection in > 80 % of patients). Salvage brachytherapy alone was administered in 81 patients (78 %), with a median total dose of 56.7 Gy. Salvage brachytherapy in combination with external beam radiotherapy (EBRT) was performed in 23/104 patients (32 %), using a median total dose of D{sub REF} = 24 Gy. Simultaneously to PDR brachytherapy, concomitant chemotherapy was administered in 58/104 (55.8 %) patients. A single session of interstitial hyperthermia was also used to treat 33/104 (31.7 %) patients. The analysis was performed after a median follow-up of 60 months. Calculated according to Kaplan-Meier, local tumor control rates after 2, 5, and 10 years were 92.5, 82.4, and 58.9 %, respectively. Comparing results of salvage PDR brachytherapy with or without simultaneous chemotherapy, the 10-year local control rates were 76 vs. 39 % (p= 0014), respectively. No other patient- or treatment-related parameters had a significant influence on treatment results. Soft tissue necrosis or bone necrosis developed in 18/104 (17.3 %) and 11/104 (9.6 %) patients, respectively, but only 3 % of patients required surgical treatment. PDR interstitial brachytherapy with simultaneous chemotherapy is a very effective and, in experienced hands, also a safe treatment modality in selected patients with head and neck cancer in previously irradiated areas. (orig.) [German] Es erfolgte die Analyse der Langzeitergebnisse einer protokollbasierten interstitiellen Brachytherapie (Re-Bestrahlung) mit simultaner Chemotherapie und interstitieller Hyperthermie

  11. American Society for Radiation Oncology (ASTRO) and American College of Radiology (ACR) practice guideline for the transperineal permanent brachytherapy of prostate cancer.

    Science.gov (United States)

    Rosenthal, Seth A; Bittner, Nathan H J; Beyer, David C; Demanes, D Jeffrey; Goldsmith, Brian J; Horwitz, Eric M; Ibbott, Geoffrey S; Lee, W Robert; Nag, Subir; Suh, W Warren; Potters, Louis

    2011-02-01

    Transperineal permanent prostate brachytherapy is a safe and efficacious treatment option for patients with organ-confined prostate cancer. Careful adherence to established brachytherapy standards has been shown to improve the likelihood of procedural success and reduce the incidence of treatment-related morbidity. A collaborative effort of the American College of Radiology (ACR) and American Society for Therapeutic Radiation Oncology (ASTRO) has produced a practice guideline for permanent prostate brachytherapy. The guideline defines the qualifications and responsibilities of all the involved personnel, including the radiation oncologist, physicist and dosimetrist. Factors with respect to patient selection and appropriate use of supplemental treatment modalities such as external beam radiation and androgen suppression therapy are discussed. Logistics with respect to the brachytherapy implant procedure, the importance of dosimetric parameters, and attention to radiation safety procedures and documentation are presented. Adherence to these practice guidelines can be part of ensuring quality and safety in a successful prostate brachytherapy program.

  12. American Society for Radiation Oncology (ASTRO) and American College of Radiology (ACR) practice guideline for the performance of high-dose-rate brachytherapy.

    Science.gov (United States)

    Erickson, Beth A; Demanes, D Jeffrey; Ibbott, Geoffrey S; Hayes, John K; Hsu, I-Chow J; Morris, David E; Rabinovitch, Rachel A; Tward, Jonathan D; Rosenthal, Seth A

    2011-03-01

    High-Dose-Rate (HDR) brachytherapy is a safe and efficacious treatment option for patients with a variety of different malignancies. Careful adherence to established standards has been shown to improve the likelihood of procedural success and reduce the incidence of treatment-related morbidity. A collaborative effort of the American College of Radiology (ACR) and American Society for Therapeutic Radiation Oncology (ASTRO) has produced a practice guideline for HDR brachytherapy. The guideline defines the qualifications and responsibilities of all the involved personnel, including the radiation oncologist, physicist and dosimetrists. Review of the leading indications for HDR brachytherapy in the management of gynecologic, thoracic, gastrointestinal, breast, urologic, head and neck, and soft tissue tumors is presented. Logistics with respect to the brachytherapy implant procedures and attention to radiation safety procedures and documentation are presented. Adherence to these practice guidelines can be part of ensuring quality and safety in a successful HDR brachytherapy program.

  13. Relationship between two year PSA nadir and biochemical recurrence in prostate cancer patients treated with iodine-125 brachytherapy

    Directory of Open Access Journals (Sweden)

    Carlos Antônio da Silva Franca

    2014-04-01

    Full Text Available Objective To evaluate the relationship between two year PSA nadir (PSAn after brachytherapy and biochemical recurrence rates in prostate cancer patients. Materials and Methods In the period from January 1998 to August 2007, 120 patients were treated with iodine-125 brachytherapy alone. The results analysis was based on the definition of biochemical recurrence according to the Phoenix Consensus. Results Biochemical control was observed in 86 patients (71.7%, and biochemical recurrence, in 34 (28.3%. Mean PSAn was 0.53 ng/ml. The mean follow-up was 98 months. The patients were divided into two groups: group 1, with two year PSAn < 0.5 ng/ml after brachytherapy (74 patients; 61.7%, and group 2, with two year PSAn ≥ 0.5 ng/ml after brachytherapy (46 patients; 38.3%. Group 1 presented biochemical recurrence in 15 patients (20.3%, and group 2, in 19 patients (43.2% (p < 0.02. The analysis of biochemical disease-free survival at seven years, stratified by the two groups, showed values of 80% and 64% (p < 0.02, respectively. Conclusion Levels of two year PSAn ≥ 0.5 ng/ml after brachytherapy are strongly correlated with a poor prognosis. This fact may help to identify patients at risk for disease recurrence.

  14. High dose rate versus low dose rate brachytherapy for oral cancer--a meta-analysis of clinical trials.

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    Zhenxing Liu

    Full Text Available OBJECTIVE: To compare the efficacy and safety of high dose rate (HDR and low dose rate (LDR brachytherapy in treating early-stage oral cancer. DATA SOURCES: A systematic search of MEDLINE, EMBASE and Cochrane Library databases, restricted to English language up to June 1, 2012, was performed to identify potentially relevant studies. STUDY SELECTION: Only randomized controlled trials (RCT and controlled trials that compared HDR to LDR brachytherapy in treatment of early-stage oral cancer (stages I, II and III were of interest. DATA EXTRACTION AND SYNTHESIS: Two investigators independently extracted data from retrieved studies and controversies were solved by discussion. Meta-analysis was performed using RevMan 5.1. One RCT and five controlled trials (607 patients: 447 for LDR and 160 for HDR met the inclusion criteria. The odds ratio showed no statistically significant difference between LDR group and HDR group in terms of local recurrence (OR = 1.12, CI 95% 0.62-2.01, overall mortality (OR = 1.01, CI 95% 0.61-1.66 and Grade 3/4 complications (OR = 0.86, CI 95% 0.52-1.42. CONCLUSIONS: This meta-analysis indicated that HDR brachytherapy was a comparable alternative to LDR brachytherapy in treatment of oral cancer. HDR brachytherapy might become a routine choice for early-stage oral cancer in the future.

  15. BRACHYTHERAPY ALONE OR WITH NEOADJUVANT PHOTODYNAMIC THERAPY FOR AMELANOTIC CHOROIDAL MELANOMA: Functional Outcomes and Local Tumor Control.

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    Blasi, Maria A; Laguardia, Michela; Tagliaferri, Luca; Scupola, Andrea; Villano, Antonio; Caputo, Carmela G; Pagliara, Monica M

    2016-11-01

    To compare visual outcomes and local tumor control between two groups of patients with amelanotic choroidal melanoma treated with brachytherapy alone, or neoadjuvant photodynamic therapy before brachytherapy. Patients diagnosed with amelanotic choroidal melanoma were recruited for the study and divided into two groups: brachytherapy alone (Group A) and photodynamic therapy preceding brachytherapy (Group B). Patients of both groups were selected to be comparable. Twenty-six patients with amelanotic choroidal melanoma were enrolled in the study. Within Group B, 1 month after photodynamic therapy, ultrasonography showed reduction of tumor height in 11 patients (73.4%). The mean doses of irradiation to macula and optic nerve, at baseline were 74.37 and 52.07 Gy, whereas after photodynamic therapy there was a decrease of 17.26% (P = 0.008) and 21.22% (P = 0.025), respectively. In terms of visual acuity, a mean decrease of 14 ETDRS letters and 5 ETDRS letters was observed at 24 months follow-up, in Groups A and B, respectively (P = 0.001). Photodynamic therapy as neoadjuvant therapy before brachytherapy reduces tumor thickness in 73.4% of cases. As a result, a decrease of radiation toxic effects on visual function could be obtained, without compromising disease control.

  16. High-dose-rate intraluminal brachytherapy prior to external radiochemotherapy in locally advanced esophageal cancer: preliminary results.

    Science.gov (United States)

    Safaei, Afsaneh Maddah; Ghalehtaki, Reza; Khanjani, Nezhat; Farazmand, Borna; Babaei, Mohammad; Esmati, Ebrahim

    2017-02-01

    Dysphagia is a common initial presentation in locally advanced esophageal cancer and negatively impacts patient quality of life and treatment compliance. To induce fast relief of dysphagia in patients with potentially operable esophageal cancer high-dose-rate (HDR) brachytherapy was applied prior to definitive radiochemotherapy. In this single arm phase II clinical trial between 2013 to 2014 twenty patients with locally advanced esophageal cancer (17 squamous cell and 3 adenocarcinoma) were treated with upfront 10 Gy HDR brachytherapy, followed by 50.4 Gy external beam radiotherapy (EBRT) and concurrent chemotherapy with cisplatin/5-fluorouracil. Tumor response, as measured by endoscopy and/or computed tomography scan, revealed complete remission in 16 and partial response in 4 patients (overall response rate 100%). Improvement of dysphagia was induced by brachytherapy within a few days and maintained up to the end of treatment in 80% of patients. No differences in either response rate or dysphagia resolution were found between squamous cell and adenocarcinoma histology. The grade 2 and 3 acute pancytopenia or bicytopenia reported in 4 patients, while sub-acute adverse effects with painful ulceration was seen in five patients, occurring after a median of 2 months. A perforation developed in one patient during the procedure of brachytherapy that resolved successfully with immediate surgery. Brachytherapy before EBRT was a safe and effective procedure to induce rapid and durable relief from dysphagia, especially when combined with EBRT.

  17. Endovascular brachytherapy from Re-188-filled balloon catheter to prevent restenosis following angioplasty; Endovaskulaere Brachytherapie mit einem Re-188-gefuellten Ballonkatheter zur Praevention der Restenose nach Angioplastie

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    Kotzerke, J. [Ulm Univ. (Germany). Abt. Nuklearmedizin; Kropp, J. [Technische Univ. Dresden (Germany). Klinik und Poliklinik fuer Nuklearmedizin

    2001-12-01

    Stent implantation and endovascular brachytherapy are the single effective methods to reduce restenosis after angioplasty. Gamma- and beta-emitter can be applied. The use of a liquid beta-emitter filled balloon catheter allows nuclear medicine to participate in this new concept of therapy due to the unsealed source. From various beta-emitters Re-188-perrhenate seems to be the most attractive one regarding logistic, radiation protection and costs. Feasibility of the method was demonstrated by several groups. Interim analysis of ECRIS-2 demonstrate an effectiveness comparable to the best of other irradiation data. (orig.) [German] Die endovaskulaere Brachytherapie ist neben der Stentimplantation bisher die einzige Methode, mit der die Restenoserate nach Angioplastie (PTCA) deutlich reduziert werden kann. Sowohl Gamma- wie auch Betastrahler sind einsetzbar. Die Anwendung eines fluessigen Betastrahlers in einem Ballonkatheter erlaubt dem Nuklearmediziner, an diesem Therapiekonzept zu partizipieren, da es sich um die Anwendung eines offenen radioaktiven Isotops handelt. Von den diversen moeglichen Betastrahlern erscheint Re-188-Perrhenat am geeignetsten zu sein im Hinblick auf die Logistik, den Strahlenschutz und die Kosten. Die Praktikabilitaet dieser Methode wurde von mehreren Zentren bestaetigt. Eine Zwischenauswertung der ECRIS-2-Studie aus Ulm ergibt Daten, die grossen amerikanischen Studien keineswegs nachstehen. (orig.)

  18. Liver malignancies: CT-guided interstitial brachytherapy in patients with unfavorable lesions for thermal ablation.

    Science.gov (United States)

    Ricke, Jens; Wust, Peter; Wieners, Gero; Beck, Alexander; Cho, Chie Hee; Seidensticker, Max; Pech, Maciej; Werk, Michael; Rosner, Christian; Hänninen, Enrique Lopez; Freund, Torsten; Felix, Roland

    2004-11-01

    To evaluate computed tomography (CT)-guided brachytherapy in patients with very large liver malignancies or with liver tumors located adjacent to the liver hilum. In this prospective nonrandomized phase II trial, we treated 20 patients (19 liver metastases and one cholangiocarcinoma) with CT-guided high-dose-rate (HDR) brachytherapy using a (192) Iridium source. All patients demonstrated no functional liver degradation prior to irradiation. Entry criteria were liver tumors > 5 cm (group A, n = 11, no upper limit) or liver tumors brachytherapy was performed with three dimensional (3D) CT data acquired after percutaneous applicator positioning. Magnetic resonance (MR) imaging follow-up was performed 6 weeks and every 3 months post intervention. Primary endpoints were complications, local tumor control (absence of tumor growth after treatment followed by shrinkage of the lesion starting at 6 months) and progression-free survival. The mean tumor diameter was 7.7 cm (range, 5.5-10.8 cm) in group A, 3.6 cm (range, 2.2-4.9 cm) in group B. On average, a minimal dose of 17 Gy in the target volume was applied (range, 12-25 Gy). Severe side effects were recorded in two patients (10%). One patient demonstrated an obstructive jaundice caused by tumor edema after irradiation of a metastasis adjacent to the bile duct bifurcation. One patient developed intra-abdominal hemorrhage that was treated by a single blood transfusion and has ceased. We frequently encountered moderate increases of liver enzymes (70% of patients) and bilirubin (50% of patients) without clinical symptoms and thus considered to be insignificant. The median follow-up was 13 months. In group A (tumors > 5 cm), primary local tumor control after 6 and 12 months was 74% and 40%, respectively; in group B, it was 100% and 71%, respectively. All but one local recurrence (in a patient with diffuse tumor progression) were successfully treated during another CT-guided brachytherapy leading to a primary assisted local

  19. Distant Metastases Following Permanent Interstitial Brachytherapy for Patients With Clinically Localized Prostate Cancer

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    Taira, Al V. [Western Radiation Oncology, Mountain View, California (United States); Merrick, Gregory S., E-mail: gmerrick@urologicresearchinstitute.org [Schiffler Cancer Center, Wheeling Jesuit University, Wheeling, West Virginia (United States); Galbreath, Robert W.; Butler, Wayne M.; Lief, Jonathan [Schiffler Cancer Center, Wheeling Jesuit University, Wheeling, West Virginia (United States); Adamovich, Edward [Department of Pathology, Wheeling Hospital, Wheeling, West Virginia (United States); Wallner, Kent E. [Puget Sound Healthcare Corporation, Group Health Cooperative, University of Washington, Seattle, Washington (United States)

    2012-02-01

    Purpose: Recent publications have suggested high-risk patients undergoing radical prostatectomy have a lower risk of distant metastases and improved cause-specific survival (CSS) than patients receiving definitive external beam radiation therapy (XRT). To date, none of these studies has compared distant metastases and CSS in brachytherapy patients. In this study, we evaluate such parameters in a consecutive cohort of brachytherapy patients. Methods and Materials: From April 1995 to June 2007, 1,840 consecutive patients with clinically localized prostate cancer were treated with brachytherapy. Risk groups were stratified according to National Comprehensive Cancer Network ( (www.nccn.org)) guidelines. Subgroups of 658, 893, and 289 patients were assigned to low, intermediate, and high-risk categories. Median follow-up was 7.2 years. Along with brachytherapy implantation, 901 (49.0%) patients received supplemental XRT, and 670 (36.4%) patients received androgen deprivation therapy (median duration, 4 months). The mode of failure (biochemical, local, or distant) was determined for each patient for whom therapy failed. Cause of death was determined for each deceased patient. Multiple parameters were evaluated for impact on outcome. Results: For the entire cohort, metastases-free survival (MFS) and CSS at 12 years were 98.1% and 98.2%, respectively. When rates were stratified by low, intermediate, and high-risk groups, the 12-year MFS was 99.8%, 98.1%, and 93.8% (p < 0.001), respectively. CSS rates were 99.8%, 98.0%, and 95.3% (p < 0.001) for low, intermediate, and high-risk groups, respectively. Biochemical progression-free survival was 98.7%, 95.9% and 90.4% for low, intermediate, and high-risk patients, respectively (p < 0.001). In multivariate Cox-regression analysis, MFS was mostly closely related to Gleason score and year of treatment, whereas CSS was most closely associated with Gleason score. Conclusions: Excellent CSS and MFS rates are achievable with high

  20. LOW POWER BRACHYTHERAPY IN COMBINED TREATMENT IN PATIENTS WITH INTERMEDIATE RISK OF LOCALIZED PROST ATE CANCER

    Directory of Open Access Journals (Sweden)

    V. A. Biryukov

    2014-01-01

    Full Text Available Objective. Estimation of the effectiveness of low power brachytherapy sources I-125 in the combined treatment in group of patients of intermediate risk of localized prostate cancer.Material and methods. The study included 126 patients with prostate cancer of intermediate risk. 104 patients (83,9% were conducted low power brachytherapy I‑125 in combination with hormone therapy by analogues of LHWG. 22 patients (16.1% received external beam irradiation in combination with brachytherapy I‑125 and hormonal treatment. Relapse-free survival of patients was evaluated in accordance with the criteria Phoenix (Nadir PSA + ng/ml. Evaluation of side effects of radiation treatment were carried out according to the RTOG criteria.Results. PSA relapse-free survival in the group of brachytherapy and hormone treatment at the time of observation 5 years amounted to 97.1%. In the group of combined radiation therapy with brachytherapy, and hormonal treatment PSA relapse-free survival rate was 95.5%.In both groups, relapse-free survival was noted in 96,8% of cases. Tumor-specific and overall survival in bothgroups was 100%. The major complications of treatment in both groups were radiation urethritis 1 to 2 degrees in 9.5% of cases (12 patients, urethral stricture in 5 patients (3.9% of cases, acute urinary retention in 1 patient (0.8% of cases and late radiation rectitis of 2 degree in 1.58% of cases (2 patients.Conclusions. It is possible to draw tentative conclusions about the high rate of survival without progression in both treatment groups on the background of the relatively low frequency of adverse reactions. It is necessary further follow-up for patients with estimating of survival for a longer period.

  1. Suitability of point kernel dose calculation techniques in brachytherapy treatment planning

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    Lakshminarayanan Thilagam

    2010-01-01

    Full Text Available Brachytherapy treatment planning system (TPS is necessary to estimate the dose to target volume and organ at risk (OAR. TPS is always recommended to account for the effect of tissue, applicator and shielding material heterogeneities exist in applicators. However, most brachytherapy TPS software packages estimate the absorbed dose at a point, taking care of only the contributions of individual sources and the source distribution, neglecting the dose perturbations arising from the applicator design and construction. There are some degrees of uncertainties in dose rate estimations under realistic clinical conditions. In this regard, an attempt is made to explore the suitability of point kernels for brachytherapy dose rate calculations and develop new interactive brachytherapy package, named as BrachyTPS, to suit the clinical conditions. BrachyTPS is an interactive point kernel code package developed to perform independent dose rate calculations by taking into account the effect of these heterogeneities, using two regions build up factors, proposed by Kalos. The primary aim of this study is to validate the developed point kernel code package integrated with treatment planning computational systems against the Monte Carlo (MC results. In the present work, three brachytherapy applicators commonly used in the treatment of uterine cervical carcinoma, namely (i Board of Radiation Isotope and Technology (BRIT low dose rate (LDR applicator and (ii Fletcher Green type LDR applicator (iii Fletcher Williamson high dose rate (HDR applicator, are studied to test the accuracy of the software. Dose rates computed using the developed code are compared with the relevant results of the MC simulations. Further, attempts are also made to study the dose rate distribution around the commercially available shielded vaginal applicator set (Nucletron. The percentage deviations of BrachyTPS computed dose rate values from the MC results are observed to be within plus/minus 5

  2. Neodadjuvante und adjuvante Kurzzeit-Hormontherapie in Kombination mit konformaler HDR-Brachytherapie beim Prostatakarzinom

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    Martin T

    2004-01-01

    Full Text Available Zielsetzung: Auswertung der Behandlungsergebnisse der neoadjuvanten und adjuvanten Kurzzeit-Hormontherapie kombiniert mit konformaler HDR-Brachytherapie und externer Radiotherapie beim Prostatakarzinom. Patienten und Methoden: Von 01/97 bis 09/99 behandelten wir 102 Patienten mit Prostatakarzinomen im Stadium T1–3 N0 M0. Im Stadium T1–2 befanden sich 71, im Stadium T3 31 Patienten. Der mediane prätherapeutische PSA-Wert betrug 15,3 ng/ml. Nach ultraschallgesteuerter transrektaler Implantation von vier Afterloadingnadeln erfolgte die CT-gestützte 3D-Brachytherapie- Planung. Alle Patienten erhielten vier HDR-Implantate mit einer Referenzdosis von 5 Gy oder 7 Gy pro Implantat. Die Zeit zwischen jedem Implantat betrug jeweils 14 Tage. Nach der Brachytherapie folgte die externe Radiotherapie bis 39,6 Gy oder 45,0 Gy. Alle Patienten erhielten eine neoadjuvante und adjuvante Kurzzeit-Hormontherapie, die 2–19 Monate vor der Brachytherapie eingeleitet und 3 Monate nach Abschluß der externen Radiotherapie abgesetzt wurde (mediane Dauer: 9 Monate. Ergebnisse: Die mediane Nachbeobachtungszeit war 2,6 Jahre (range: 2,0–4,1 Jahre. Die biochemische Kontrollrate betrug 82 % nach 3 Jahren. Bei 14/102 Patienten registrierten wir ein biochemisches Rezidiv, bei 5/102 Patienten ein klinisches Rezidiv. Das Gesamtüberleben betrug 90 %, das krankheitsspezifische Überleben 98,0 % nach 3 Jahren. Ein Patient entwickelte eine prostato-urethro-rektale Fistel als späte Grad 4-Toxizität. Akute Grad-3 Toxizitäten traten bei 4 %, späte Grad-3 Toxizitäten bei 5 % der Patienten auf. Schlußfolgerung: Die neoadjuvante und adjuvante Kurzzeit-Hormontherapie kombiniert mit konformaler HDR-Brachytherapie und externer Radiotherapie erweist sich als sichere und wirksame Behandlungsmodalität beim Prostatakarzinom mit minimalen behandlungsbedingten Toxizitäten und einer vielversprechenden biochemischen Kontrollrate nach medianer Nachbeobachtungszeit von 2,6 Jahren.

  3. Intensity Modulated Proton Beam Radiation for Brachytherapy in Patients With Cervical Carcinoma

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    Clivio, Alessandro [Oncology Institute of Southern Switzerland, Bellinzona (Switzerland); Kluge, Anne [Department of Radiation Oncology, Charité University Hospital, Berlin (Germany); Cozzi, Luca, E-mail: lucozzi@iosi.ch [Oncology Institute of Southern Switzerland, Bellinzona (Switzerland); Köhler, Christhardt [Department of Gynecology, Charité University Hospital, Berlin (Germany); Neumann, Oliver [Department of Radiation Oncology, Charité University Hospital, Berlin (Germany); Vanetti, Eugenio [Oncology Institute of Southern Switzerland, Bellinzona (Switzerland); Wlodarczyk, Waldemar; Marnitz, Simone [Department of Radiation Oncology, Charité University Hospital, Berlin (Germany)

    2013-12-01

    Purpose: To evaluate intensity modulated proton therapy (IMPT) in patients with cervical cancer in terms of coverage, conformity, and dose–volume histogram (DVH) parameters correlated with recommendations from magnetic resonance imaging (MRI)-guided brachytherapy. Methods and Materials: Eleven patients with histologically proven cervical cancer underwent primary chemoradiation for the pelvic lymph nodes, the uterus, the cervix, and the parametric region, with a symmetric margin of 1 cm. The prescription was for 50.4 Gy, with 1.8 Gy per fraction. The prescribed dose to the parametria was 2.12 Gy up to 59.36 Gy in 28 fractions as a simultaneous boost. For several reasons, the patients were unable to undergo brachytherapy. As an alternative, IMPT was planned with 5 fractions of 6 Gy to the cervix, including the macroscopic tumor with an MRI-guided target definition, with an isotropic margin of 5 mm for planning target volume (PTV) definition. Groupe-Europeen de Curietherapie and European society for Radiotherapy and Oncology (GEC-ESTRO) criteria were used for DVH evaluation. Reference comparison plans were optimized for volumetric modulated rapid arc (VMAT) therapy with the RapidArc (RA). Results: The dose to the high-risk volume was calculated with α/β = 10 with 89.6 Gy. For IMPT, the clinical target volume showed a mean dose of 38.2 ± 5.0 Gy (35.0 ±1.8 Gy for RA). The D{sub 98%} was 31.9 ± 2.6 Gy (RA: 30.8 ± 1.0 Gy). With regard to the organs at risk, the 2Gy Equivalent Dose (EQD2) (α/β = 3) to 2 cm{sup 3} of the rectal wall, sigmoid wall, and bladder wall was 62.2 ± 6.4 Gy, 57.8 ± 6.1 Gy, and 80.6 ± 8.7 Gy (for RA: 75.3 ± 6.1 Gy, 66.9 ± 6.9 Gy, and 89.0 ± 7.2 Gy, respectively). For the IMPT boost plans in combination with external beam radiation therapy, all DVH parameters correlated with <5% risk for grades 2 to 4 late gastrointestinal and genitourinary toxicity. Conclusion: In patients who are not eligible for brachytherapy, IMPT as a boost

  4. Intravitreal bevacizumab combined with plaque brachytherapy reduces melanoma tumor volume and enhances resolution of exudative detachment

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    Houston SK

    2013-01-01

    Full Text Available Samuel K Houston,1 Nisha V Shah,1 Christina Decatur,1 Marcela Lonngi,1 William Feuer,1 Arnold M Markoe,2 Timothy G Murray1–31Department of Ophthalmology, 2Department of Radiation Oncology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, 3Murray Ocular Oncology and Retina, Miami, FL, USABackground: The purpose of this study was to evaluate intravitreal bevacizumab as an adjuvant treatment to plaque brachytherapy in the treatment of choroidal melanoma.Methods: This was a retrospective, consecutive study of 124 patients treated from 2007 to 2009 for choroidal melanoma with plaque brachytherapy. Patients were treated with I-125 plaque brachytherapy with 2 mm margins and 85 Gy to the tumor apex. Consecutive patients were injected intravitreally with 2.5 mg/0.1 mL bevacizumab at a site away from the primary tumor and immediately following plaque removal. Choroidal melanomas were observed using indirect ophthalmoscopy, wide-angle photography, and ultrasound. The main outcome measures were tumor volume, resolution of exudative retinal detachment, and visual acuity.Results: One hundred and twenty-four patients met our inclusion criteria and were included in the analysis. The mean patient age was 65.7 years, and the mean apical tumor height was 4.0 ± 2.7 mm and basal diameter was 12.7 ± 3.0 mm. Mean follow-up was 24 months. Prior to treatment, 100% of tumors had exudative retinal detachment, and pretreatment visual acuity was 20/55 (median 20/40. Tumor control was 100%, metastasis was 0% at last follow-up, and 89.8% had complete resolution of exudative retinal detachment, with a mean time to resolution of 3.36 months. At one month, 43% had complete resolution of exudative retinal detachment, which increased to 73% at 4 months. Visual acuity was 20/62 (median 20/40 at 4 months, with stabilization to 20/57 (median 20/40 at 8 months, 20/56 (median 20/30 at 12 months, and 20/68 (median 20/50 at 24 months. Tumor

  5. SU-E-T-397: Include Organ Deformation Into Dose Calculation of Prostate Brachytherapy

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    Shao, Y; Shen, D; Chen, R; Wang, A; Lian, J [University of North Carolina, Chapel Hill, NC (United States)

    2014-06-01

    Purpose: Prostate brachytherapy is an important curative treatment for patients with localized prostate cancer. In brachytherapy, rectal balloon is generally needed to adjust for unfavorable prostate position for seed placement. However, rectal balloon causes prostate deformation, which is not accounted for in dosimetric planning. Therefore, it is possible that brachytherapy dosimetry deviates significantly from initial plan when prostate returns to its non-deformed state (after procedure). The goal of this study is to develop a method to include prostate deformation into the treatment planning of brachytherapy dosimetry. Methods: We prospectively collected ultrasound images of prostate pre- and post- rectal balloon inflation from thirty five consecutive patients undergoing I-125 brachytherapy. Based on the cylinder coordinate systems, we learned the initial coordinate transformation parameters between the manual segmentations of both deformed and non-deformed prostates of each patient in training set. With the nearest-neighbor interpolation, we searched the best transformation between two coordinate systems to maximum the mutual information of deformed and non-deformed images. We then mapped the implanted seeds of five selected patients from the deformed prostate into non-deformed prostate. The seed position is marked on original pre-inflation US image and it is imported into VariSeed software for dose calculation. Results: The accuracy of image registration is 87.5% as quantified by Dice Index. The prostate coverage V100% dropped from 96.5±0.5% of prostate deformed plan to 91.9±2.6% (p<0.05) of non-deformed plan. The rectum V100% decreased from 0.44±0.26 cc to 0.10±0.18 cc (p<0.05). The dosimetry of the urethra showed mild change but not significant: V150% changed from 0.05±0.10 cc to 0.14±0.15 cc (p>0.05) and D1% changed from 212.9±37.3 Gy to 248.4±42.8 Gy (p>0.05). Conclusion: We have developed a deformable image registration method that allows

  6. Using LiF:Mg,Cu,P TLDs to estimate the absorbed dose to water in liquid water around an {sup 192}Ir brachytherapy source

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    Lucas, P. Avilés, E-mail: paz.aviles@ciemat.es; Aubineau-Lanièce, I.; Lourenço, V.; Vermesse, D.; Cutarella, D. [CEA, LIST, Laboratoire National Henri Becquerel, 91191 Gif-sur-Yvette (France)

    2014-01-15

    Purpose: The absorbed dose to water is the fundamental reference quantity for brachytherapy treatment planning systems and thermoluminescence dosimeters (TLDs) have been recognized as the most validated detectors for measurement of such a dosimetric descriptor. The detector response in a wide energy spectrum as that of an{sup 192}Ir brachytherapy source as well as the specific measurement medium which surrounds the TLD need to be accounted for when estimating the absorbed dose. This paper develops a methodology based on highly sensitive LiF:Mg,Cu,P TLDs to directly estimate the absorbed dose to water in liquid water around a high dose rate {sup 192}Ir brachytherapy source. Methods: Different experimental designs in liquid water and air were constructed to study the response of LiF:Mg,Cu,P TLDs when irradiated in several standard photon beams of the LNE-LNHB (French national metrology laboratory for ionizing radiation). Measurement strategies and Monte Carlo techniques were developed to calibrate the LiF:Mg,Cu,P detectors in the energy interval characteristic of that found when TLDs are immersed in water around an{sup 192}Ir source. Finally, an experimental system was designed to irradiate TLDs at different angles between 1 and 11 cm away from an {sup 192}Ir source in liquid water. Monte Carlo simulations were performed to correct measured results to provide estimates of the absorbed dose to water in water around the {sup 192}Ir source. Results: The dose response dependence of LiF:Mg,Cu,P TLDs with the linear energy transfer of secondary electrons followed the same variations as those of published results. The calibration strategy which used TLDs in air exposed to a standard N-250 ISO x-ray beam and TLDs in water irradiated with a standard{sup 137}Cs beam provided an estimated mean uncertainty of 2.8% (k = 1) in the TLD calibration coefficient for irradiations by the {sup 192}Ir source in water. The 3D TLD measurements performed in liquid water were obtained with a

  7. Magnetic resonance image-guided brachytherapy for cervical cancer. Prognostic factors for survival

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon-Joo; Kim, Joo-Young [National Cancer Center, Proton Therapy Center, Goyang (Korea, Republic of); National Cancer Center, Center for Uterine Cancer, Goyang (Korea, Republic of); Kim, Youngkyong; Lim, Young Kyung; Jeong, Jonghwi [National Cancer Center, Proton Therapy Center, Goyang (Korea, Republic of); Jeong, Chiyoung [National Cancer Center, Proton Therapy Center, Goyang (Korea, Republic of); University of Ulsan College of Medicine, Department of Radiation Oncology, Asan Medical Center, Seoul (Korea, Republic of); Kim, Meyoung [National Cancer Center, Proton Therapy Center, Goyang (Korea, Republic of); Dongnam Inst. of Radiology and Medical Sciences, Research center, Busan (Korea, Republic of); Lim, Myong Cheol; Seo, Sang-Soo; Park, Sang-Yoon [National Cancer Center, Center for Uterine Cancer, Goyang (Korea, Republic of)

    2016-12-15

    The purpose of this work was to identify prognostic factors for survival after magnetic resonance image (MRI)-guided brachytherapy combined with external beam radiotherapy for cervical cancer. External beam radiotherapy of 45-50.4 Gy was delivered by either three-dimensional conformal radiotherapy or helical tomotherapy. Patients also received high-dose-rate MRI-guided brachytherapy of 5 Gy in 6 fractions. We analyzed 128 patients with International Federation of Gynecology and Obstetrics stage IB-IVB cervical cancer who underwent MRI-guided brachytherapy. Most patients (96 %) received concurrent chemotherapy. Pelvic lymph node metastases and para-aortic lymphadenopathies were found in 62 % and 14 % of patients, respectively. The median follow-up time was 44 months. Complete remission was achieved in 119 of 128 patients (93 %). The 5-year local recurrence-free, cancer-specific, and overall survival rates were 94, 89, and 85 %, respectively. Negative pelvic lymphadenopathy, gross tumor volume (GTV) dose covering 90 % of the target (GTV D90) of >110 Gy, and treatment duration ≤56 days were associated with better overall survival in univariate analyses. Multivariable analysis showed that GTV D90 of >110 Gy and treatment duration ≤56 days were possibly associated with overall survival with near-significant P-values of 0.062 and 0.073, respectively. The outcome of MRI-guided brachytherapy combined with external beam radiotherapy in patients with cervical cancer was excellent. GTV D90 of >110 Gy and treatment duration ≤56 days were potentially associated with overall survival. (orig.) [German] Ziel der Arbeit war es, prognostische Faktoren nach magnetresonanztomographisch (MRT-)gesteuerter Brachytherapie in Verbindung mit externer Strahlentherapie fuer Gebaermutterhalskrebs zu identifizieren. Externe Strahlentherapie von 45-50,4 Gy erfolgte entweder mittels dreidimensionaler konformaler Strahlentherapie oder helikaler Tomotherapie. Die Patientinnen erhielten auch

  8. Macular epiretinal brachytherapy in treated age-related macular degeneration: MERITAGE study: twelve-month safety and efficacy results.

    Science.gov (United States)

    Dugel, Pravin U; Petrarca, Robert; Bennett, Michael; Barak, Adiel; Weinberger, Dov; Nau, Jeffrey; Jackson, Timothy L

    2012-07-01

    To evaluate the safety and efficacy of epimacular brachytherapy (EMB) for the treatment of chronic, active, neovascular age-related macular degeneration (AMD). Prospective, multicenter, interventional, noncontrolled clinical trial. Fifty-three eyes of 53 participants with neovascular AMD requiring frequent anti-vascular endothelial growth factor (VEGF) retreatment. Participants underwent pars plana vitrectomy with a single 24-Gy dose of EMB delivered using an intraocular, handheld cannula containing a strontium 90/yttrium 90 source positioned over the active lesion. Participants were retreated with ranibizumab administered monthly as needed, using predefined retreatment criteria. Optical coherence tomography (OCT) was undertaken monthly, with images assessed by an independent reading center. Coprimary outcomes at 12 months were proportion of participants with stable vision (losing brachytherapy produces stable visual acuity in most participants with previously treated, active disease. Epimacular brachytherapy may reduce the need for frequent anti-VEGF retreatment. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  9. Real-time inverse high-dose-rate brachytherapy planning with catheter optimization by compressed sensing-inspired optimization strategies.

    Science.gov (United States)

    Guthier, C V; Aschenbrenner, K P; Müller, R; Polster, L; Cormack, R A; Hesser, J W

    2016-08-21

    This paper demonstrates that optimization strategies derived from the field of compressed sensing (CS) improve computational performance in inverse treatment planning (ITP) for high-dose-rate (HDR) brachytherapy. Following an approach applied to low-dose-rate brachytherapy, we developed a reformulation of the ITP problem with the same mathematical structure as standard CS problems. Two greedy methods, derived from hard thresholding and subspace pursuit are presented and their performance is compared to state-of-the-art ITP solvers. Applied to clinical prostate brachytherapy plans speed-up by a factor of 56-350 compared to state-of-the-art methods. Based on a Wilcoxon signed rank-test the novel method statistically significantly decreases the final objective function value (p  plans are either clinically equivalent or show a better performance with respect to dosimetric measures.

  10. Applicator Attenuation Effect on Dose Calculations of Esophageal High-Dose Rate Brachytherapy Using EDR2 Film

    Directory of Open Access Journals (Sweden)

    Seyed Mohsen Hosseini Daghigh

    2012-03-01

    Full Text Available Introduction Interaluminal brachytherapy is one of the important methods of esophageal cancer treatment. The effect of applicator attenuation is not considered in dose calculation method released by AAPM-TG43. In this study, the effect of High-Dose Rate (HDR brachytherapy esophageal applicator on dose distribution was surveyed in HDR brachytherapy. Materials and Methods A cylindrical PMMA phantom was built in order to be inserted by various sizes of esophageal applicators. EDR2 films were placed at 33 mm from Ir-192 source and irradiated with 1.5 Gy after planning using treatment planning system for all applicators. Results The results of film dosimetry in reference point for 6, 8, 10, and 20 mm applicators were 1.54, 1.53, 1.48, and 1.50 Gy, respectively. The difference between practical and treatment planning system results was 0.023 Gy (

  11. A new modification of combining vacuum therapy and brachytherapy in large subfascial soft-tissue sarcomas of the extremities

    Energy Technology Data Exchange (ETDEWEB)

    Rudert, Maximilian; Holzapfel, Boris Michael [Dept. of Orthopedics, Univ. of Wuerzburg (Germany); Dept. of Orthopedics and Traumatology, Klinikum Muenchen rechts der Isar, Technical Univ. of Munich (Germany); Winkler, Cornelia; Kneschaurek, Peter; Molls, Michael; Roeper, Barbara [Dept. of Radiation Oncology, Technical Univ. of Munich (Germany); Rechl, Hans; Gradinger, Reiner [Dept. of Orthopedics and Traumatology, Klinikum Muenchen rechts der Isar, Technical Univ. of Munich (Germany)

    2010-04-15

    Purpose: To present a modification of a technique combining the advantages of brachytherapy for local radiation treatment and vacuum therapy for wound conditioning after resection of subfascial soft-tissue sarcomas (STS) of the extremities. Patients and methods: Between January and May 2008, four patients with large (> 10 cm) subfascial STS of the thigh underwent marginal tumor excision followed by early postoperative HDR (high-dose-rate) brachytherapy (iridium-192) and vacuum therapy as part of their interdisciplinary treatment. The sponge of the vacuum system was used to stabilize brachytherapy applicators in parallel positions and to allow for a maximal wound contraction in the early postoperative phase, thus preventing seroma and deterioration of local dose distribution as optimized in computed tomography-(CT-)based three-dimensional conformal treatment planning. In three patients this was followed by external-beam radiotherapy. Acute wound complications and late effects according to LENT-SOMA after 4-8 months of follow-up were recorded. Results: the combination of vacuum and brachytherapy was applicable in all patients. CT scans from the 1st postoperative day showed the shrinkage of the sponge located in the tumor bed with the brachytherapy applicators in the intended position and easily visible. 15-18 Gy in fractions of 3 Gy bid prescribed to 5 mm tissue depth were applied over the next days with removal of the sponge and applicators on days 5-8. No early or late toxicity exceeding grade 2 was observed. The mean Enneking Score for functional outcome was 63% (perfect function = 100%). Conclusion: The combination of vacuum and brachytherapy is applicable and safe in the treatment of large subfascial STS. (orig.)

  12. MO-FG-210-01: Commissioning An US System for Brachytherapy: An Overview of Physics, Instrumentation, and Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Z. [Duke University Medical Center (United States)

    2015-06-15

    Ultrasound (US) is one of the most widely used imaging modalities in medical practice. Since US imaging offers real-time imaging capability, it has becomes an excellent option to provide image guidance for brachytherapy (IGBT). (1) The physics and the fundamental principles of US imaging are presented, and the typical steps required to commission an US system for IGBT is provided for illustration. (2) Application of US for prostate HDR brachytherapy, including partial prostate treatments using MR-ultrasound co-registration to enable a focused treatment on the disease within the prostate is also presented. Prostate HDR with US image guidance planning can benefit from real time visualization of the needles, and fusion of the ultrasound images with T2 weighted MR allows the focusing of the treatment to the specific areas of disease within the prostate, so that the entire gland need not be treated. Finally, (3) ultrasound guidance for an eye plaque program is presented. US can be a key component of placement and QA for episcleral plaque brachytherapy for ocular cancer, and the UCLA eye plaque program with US for image guidance is presented to demonstrate the utility of US verification of plaque placement in improving the methods and QA in episcleral plaque brachytherapy. Learning Objectives: To understand the physics of an US system and the necessary aspects of commissioning US for image guided brachytherapy (IGBT). To understand real time planning of prostate HDR using ultrasound, and its application in partial prostate treatments using MR-ultrasound fusion to focus treatment on disease within the prostate. To understand the methods and QA in applying US for localizing the target and the implant during a episcleral plaque brachytherapy procedures.

  13. MO-FG-210-02: Implementation of Image-Guided Prostate HDR Brachytherapy Using MR-Ultrasound Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Libby, B. [University of Virginia (United States)

    2015-06-15

    Ultrasound (US) is one of the most widely used imaging modalities in medical practice. Since US imaging offers real-time imaging capability, it has becomes an excellent option to provide image guidance for brachytherapy (IGBT). (1) The physics and the fundamental principles of US imaging are presented, and the typical steps required to commission an US system for IGBT is provided for illustration. (2) Application of US for prostate HDR brachytherapy, including partial prostate treatments using MR-ultrasound co-registration to enable a focused treatment on the disease within the prostate is also presented. Prostate HDR with US image guidance planning can benefit from real time visualization of the needles, and fusion of the ultrasound images with T2 weighted MR allows the focusing of the treatment to the specific areas of disease within the prostate, so that the entire gland need not be treated. Finally, (3) ultrasound guidance for an eye plaque program is presented. US can be a key component of placement and QA for episcleral plaque brachytherapy for ocular cancer, and the UCLA eye plaque program with US for image guidance is presented to demonstrate the utility of US verification of plaque placement in improving the methods and QA in episcleral plaque brachytherapy. Learning Objectives: To understand the physics of an US system and the necessary aspects of commissioning US for image guided brachytherapy (IGBT). To understand real time planning of prostate HDR using ultrasound, and its application in partial prostate treatments using MR-ultrasound fusion to focus treatment on disease within the prostate. To understand the methods and QA in applying US for localizing the target and the implant during a episcleral plaque brachytherapy procedures.

  14. MO-FG-210-03: Intraoperative Ultrasonography-Guided Positioning of Plaque Brachytherapy in the Treatment of Choroidal Melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Lamb, J. [University of California, Los Angeles (United States)

    2015-06-15

    Ultrasound (US) is one of the most widely used imaging modalities in medical practice. Since US imaging offers real-time imaging capability, it has becomes an excellent option to provide image guidance for brachytherapy (IGBT). (1) The physics and the fundamental principles of US imaging are presented, and the typical steps required to commission an US system for IGBT is provided for illustration. (2) Application of US for prostate HDR brachytherapy, including partial prostate treatments using MR-ultrasound co-registration to enable a focused treatment on the disease within the prostate is also presented. Prostate HDR with US image guidance planning can benefit from real time visualization of the needles, and fusion of the ultrasound images with T2 weighted MR allows the focusing of the treatment to the specific areas of disease within the prostate, so that the entire gland need not be treated. Finally, (3) ultrasound guidance for an eye plaque program is presented. US can be a key component of placement and QA for episcleral plaque brachytherapy for ocular cancer, and the UCLA eye plaque program with US for image guidance is presented to demonstrate the utility of US verification of plaque placement in improving the methods and QA in episcleral plaque brachytherapy. Learning Objectives: To understand the physics of an US system and the necessary aspects of commissioning US for image guided brachytherapy (IGBT). To understand real time planning of prostate HDR using ultrasound, and its application in partial prostate treatments using MR-ultrasound fusion to focus treatment on disease within the prostate. To understand the methods and QA in applying US for localizing the target and the implant during a episcleral plaque brachytherapy procedures.

  15. Inter-application displacement of brachytherapy dose received by the bladder and rectum of the patients with inoperable cervical cancer

    Science.gov (United States)

    Marosevic, Goran; Ljuca, Dzenita; Osmic, Hasan; Fazlic, Semir; Arsovski, Oliver; Mileusnic, Dusan

    2014-01-01

    Background The aim of the study was to examine on the CT basis the inter-application displacement of the positions D0.1cc, D1cc and D2cc of the brachytherapy dose applied to the bladder and rectum of the patients with inoperable cervical cancer. Patients and methods This prospective study included 30 patients with cervical cancer who were treated by concomitant chemo-radiotherapy. HDR intracavitary brachytherapy was made by the applicators type Fletcher tandem and ovoids. For each brachytherapy application the position D0.1cc was determined of the bladder and rectum that receive a brachytherapty dose. Then, based on the X, Y, and Z axis displacement, inter-application mean X, Y, and Z axis displacements were calculated as well as their displacement vectors (R). It has been analyzed whether there is statistically significant difference in inter-application displacement of the position of the brachytherapy dose D0.1cc, D1cc and D2cc of the bladder and rectum. The ANOVA test and post-hoc analysis by Tukey method were used for testing statistical importance of differences among the groups analyzed. The difference among the groups analyzed was considered significant if p < 0.05. Results There are significant inter-application displacements of the position of the brachytherapy dose D0,1cc, D1cc and D2cc of the bladder and rectum. Conclusions When we calculate the cumulative brachytherapy dose by summing up D0,1cc, D1cc and D2cc of the organs at risk for all the applications, we must bear in mind their inter-application displacement, and the fact that it is less likely that the worst scenario would indeed happen. PMID:24991211

  16. Determination of surface dose rate of indigenous (32)P patch brachytherapy source by experimental and Monte Carlo methods.

    Science.gov (United States)

    Kumar, Sudhir; Srinivasan, P; Sharma, S D; Saxena, Sanjay Kumar; Bakshi, A K; Dash, Ashutosh; Babu, D A R; Sharma, D N

    2015-09-01

    Isotope production and Application Division of Bhabha Atomic Research Center developed (32)P patch sources for treatment of superficial tumors. Surface dose rate of a newly developed (32)P patch source of nominal diameter 25 mm was measured experimentally using standard extrapolation ionization chamber and Gafchromic EBT film. Monte Carlo model of the (32)P patch source along with the extrapolation chamber was also developed to estimate the surface dose rates from these sources. The surface dose rates to tissue (cGy/min) measured using extrapolation chamber and radiochromic films are 82.03±4.18 (k=2) and 79.13±2.53 (k=2) respectively. The two values of the surface dose rates measured using the two independent experimental methods are in good agreement to each other within a variation of 3.5%. The surface dose rate to tissue (cGy/min) estimated using the MCNP Monte Carlo code works out to be 77.78±1.16 (k=2). The maximum deviation between the surface dose rates to tissue obtained by Monte Carlo and the extrapolation chamber method is 5.2% whereas the difference between the surface dose rates obtained by radiochromic film measurement and the Monte Carlo simulation is 1.7%. The three values of the surface dose rates of the (32)P patch source obtained by three independent methods are in good agreement to one another within the uncertainties associated with their measurements and calculation. This work has demonstrated that MCNP based electron transport simulations are accurate enough for determining the dosimetry parameters of the indigenously developed (32)P patch sources for contact brachytherapy applications.

  17. Specification of absorbed dose to water using model-based dose calculation algorithms for treatment planning in brachytherapy.

    Science.gov (United States)

    Tedgren, Åsa Carlsson; Carlsson, Gudrun Alm

    2013-04-21

    Model-based dose calculation algorithms (MBDCAs), recently introduced in treatment planning systems (TPS) for brachytherapy, calculate tissue absorbed doses. In the TPS framework, doses have hereto been reported as dose to water and water may still be preferred as a dose specification medium. Dose to tissue medium Dmed then needs to be converted into dose to water in tissue Dw,med. Methods to calculate absorbed dose to differently sized water compartments/cavities inside tissue, infinitesimal (used for definition of absorbed dose), small, large or intermediate, are reviewed. Burlin theory is applied to estimate photon energies at which cavity sizes in the range 1 nm-10 mm can be considered small or large. Photon and electron energy spectra are calculated at 1 cm distance from the central axis in cylindrical phantoms of bone, muscle and adipose tissue for 20, 50, 300 keV photons and photons from (125)I, (169)Yb and (192)Ir sources; ratios of mass-collision-stopping powers and mass energy absorption coefficients are calculated as applicable to convert Dmed into Dw,med for small and large cavities. Results show that 1-10 nm sized cavities are small at all investigated photon energies; 100 µm cavities are large only at photon energies <20 keV. A choice of an appropriate conversion coefficient Dw, med/Dmed is discussed in terms of the cavity size in relation to the size of important cellular targets. Free radicals from DNA bound water of nanometre dimensions contribute to DNA damage and cell killing and may be the most important water compartment in cells implying use of ratios of mass-collision-stopping powers for converting Dmed into Dw,med.

  18. Low dose rate caesium-137 implant time of intracavitary brachytherapy source of a selected oncology center in Ghana

    OpenAIRE

    John Owusu Banahene; Emmanuel Ofori Darko; Baffour Awuah

    2015-01-01

    Background: The treatment time taken for a radioactive source is found to be very important in intracavitary brachytherapy treatment. The duration of the treatment time depends on the prescribed dose requested to a reference point and the calculated dose rate to the same point. The duration of the treatment time of source is found to depend on the tumour stage. In this work, the treatment time of implant has been calculated for a Caesium-137 low dose rate brachytherapy source at an oncology f...

  19. Stereotactic body radiation therapy via helical tomotherapy to replace brachytherapy for brachytherapy-unsuitable cervical cancer patients – a preliminary result

    Directory of Open Access Journals (Sweden)

    Hsieh CH

    2013-02-01

    Full Text Available Chen-Hsi Hsieh,1–3 Hui-Ju Tien,1 Sheng-Mou Hsiao,4 Ming-Chow Wei,4 Wen-Yih Wu,4 Hsu-Dong Sun,4 Li-Ying Wang,5 Yen-Ping Hsieh,6 Yu-Jen Chen,3,7–9 Pei-Wei Shueng1,101Department of Radiation Oncology, Far Eastern Memorial Hospital, Taipei, Taiwan; 2Department of Medicine, 3Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; 4Department of Obstetrics and Gynecology, Far Eastern Memorial Hospital, Taipei, Taiwan; 5School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan; 6Department of Senior Citizen Service Management, National Taichung University of Science and Technology, Taichung, Taiwan; 7Department of Radiation Oncology, 8Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan; 9Graduate Institute of Sport Coaching Science, Chinese Culture University, Taipei, Taiwan; 10Department of Radiation Oncology, National Defense Medical Center, Taipei, TaiwanAim: To review the experience and to evaluate the results of stereotactic body radiation therapy (SBRT via helical tomotherapy (HT, for the treatment of brachytherapy-unsuitable cervical cancer.Methods: Between September 1, 2008 to January 31, 2012, nine cervical cancer patients unsuitable for brachytherapy were enrolled. All of the patients received definitive whole pelvic radiotherapy with or without chemotherapy, followed by SBRT via HT.Results: The actuarial locoregional control rate at 3 years was 78%. The mean biological equivalent dose in 2-Gy fractions of the tumor, rectum, bladder, and intestines was 76.0 ± 7.3, 73.8 ± 13.2, 70.5 ± 10.0, and 43.1 ± 7.1, respectively. Only two had residual tumors after treatment, and the others were tumor-free. Two patients experienced grade 3 acute toxicity: one had diarrhea; and another experienced thrombocytopenia. There were no grade 3 or 4 subacute toxicities. Three patients suffered from manageable rectal bleeding in

  20. Salvage brachytherapy in combination with interstitial hyperthermia for locally recurrent prostate carcinoma following external beam radiation therapy: a prospective phase II study.

    Science.gov (United States)

    Kukiełka, Andrzej M; Strnad, Vratislav; Stauffer, Paul; Dąbrowski, Tomasz; Hetnał, Marcin; Nahajowski, Damian; Walasek, Tomasz; Brandys, Piotr; Matys, Robert

    2015-06-01

    Optimal treatment for patients with only local prostate cancer recurrence after external beam radiation therapy (EBRT) failure remains unclear. Possible curative treatments are radical prostatectomy, cryosurgery, and brachytherapy. Several single institution series proved that high-dose-rate brachytherapy (HDRBT) and pulsed-dose-rate brachytherapy (PDRBT) are reasonable options for this group of patients with acceptable levels of genitourinary and gastrointestinal toxicity. A standard dose prescription and scheme have not been established yet, and the literature presents a wide range of fractionation protocols. Furthermore, hyperthermia has shown the potential to enhance the efficacy of re-irradiation. Consequently, a prospective trial is urgently needed to attain clear structured prospective data regarding the efficacy of salvage brachytherapy with adjuvant hyperthermia for locally recurrent prostate cancer. The purpose of this report is to introduce a new prospective phase II trial that would meet this need. The primary aim of this prospective phase II study combining Iridium-192 brachytherapy with interstitial hyperthermia (IHT) is to analyze toxicity of the combined treatment; a secondary aim is to define the efficacy (bNED, DFS, OS) of salvage brachytherapy. The dose prescribed to PTV will be 30 Gy in 3 fractions for HDRBT, and 60 Gy in 2 fractions for PDRBT. During IHT, the prostate will be heated to the range of 40-47°C for 60 minutes prior to brachytherapy dose delivery. The protocol plans for treatment of 77 patients.

  1. Substantial advantage of CT-planned HDR brachytherapy for cervical cancer patients compared to a historical series with regard to local control and toxicity?; Substantieller Vorteil durch CT-geplante HDR-Brachytherapie bei Zervixkarzinompatientinnen im Vergleich zu historischen Serien bezueglich lokaler Kontrolle und Toxizitaet

    Energy Technology Data Exchange (ETDEWEB)

    Marnitz, Simone [Klinik fuer Strahlentherapie der Uniklinik Koeln, Medizinische Fakultaet der Universitaet zu Koeln, CyberKnife Centrum, Koeln (Germany)

    2017-03-15

    The primary radiochemotherapy is the standard treatment for patients with nodal positive and/or locally advanced cervical carcinoma. The therapy consists of percutaneous radiotherapy, simultaneous chemotherapy with cisplatin and an intracervical brachytherapy. The application of highly standardized brachytherapy based on NMR imaging allowed an improved local contol and a considerable reduction of toxicity.

  2. Stereotactic intracavitary brachytherapy with P-32 for cystic craniopharyngiomas in children

    Energy Technology Data Exchange (ETDEWEB)

    Maarouf, Mohammad; El Majdoub, Faycal [University Hospital of Cologne, Department of Stereotaxy and Functional Neurosurgery, Cologne (Germany); University of Witten/Herdecke, Department of Stereotaxy and Functional Neurosurgery, Center of Neurosurgery, Cologne-Merheim Medical Center (CMMC), Cologne (Germany); Fuetsch, Manuel [University Hospital of Munich, Department of Neurosurgery, Munich (Germany); Hoevels, Mauritius [University Hospital of Cologne, Department of Stereotaxy and Functional Neurosurgery, Cologne (Germany); Lehrke, Ralph [St. Barbara-Klinik Hamm-Heessen, Department of Stereotaxy and Functional Neurosurgery, Hamm (Germany); Berthold, Frank [University Hospital of Cologne, Department Pediatric Oncology, Cologne (Germany); Voges, Juergen [University Hospital of Magdeburg, Department of Stereotaxy and Functional Neurosurgery, Magdeburg (Germany); Sturm, Volker [University Hospital of Cologne, Department of Stereotaxy and Functional Neurosurgery, Cologne (Germany); University Hospital of Wurzburg, Department of Neurosurgery, Wuerzburg (Germany)

    2016-03-15

    Although microsurgery remains the first-line treatment, gross total resection of cystic craniopharyngeomas (CP) is associated with significant morbidity and mortality and the addition of external irradiation to subtotal resection proves to achieve similar tumor control. However, concern regarding long-term morbidity associated with external irradiation in children still remains. With this retrospective analysis, the authors emphasize intracavitary brachytherapy using phosphorus-32 (P-32) as a treatment option for children with cystic CP. Between 1992 and 2009, 17 children (median age 15.4 years; range 7-18 years) with cystic CP underwent intracavitary brachytherapy using P-32. Eleven patients were treated for recurrent tumor cysts; 6 patients were treated primarily. MR imaging revealed solitary cysts in 7 patients; 10 patients had mixed solid-cystic lesions (median tumor volume 11.1 ml; range 0.5-78.9 ml). The median follow-up time was 61.9 months (range 16.9-196.6 months). Local cyst control could be achieved in 14 patients (82 %). Three patients showed progression of the treated cystic formation (in-field progression) after a median time of 8.3 months (range 5.3-10.3 months), which led to subsequent interventions. The development of new, defined cysts and progression of solid tumor parts (out-of-field progression) occurred in 5 patients and led to additional interventions in 4 cases. There was neither surgery-related permanent morbidity nor mortality in this study. The overall progression-free survival was 75, 63, and 52 % after 1, 3, and 5 years, respectively. Intracavitary brachytherapy using P-32 represents a safe and effective treatment option for children harboring cystic CP, even as primary treatment. However, P-32 does not clearly affect growth of solid tumor parts or the development of new cystic formations. (orig.) [German] Obwohl die Mikrochirurgie die Methode der Wahl darstellt, ist die komplette Resektion zystischer Kraniopharyngeome haeufig mit einer

  3. Human factors evaluation of remote afterloading brachytherapy: Human error and critical tasks in remote afterloading brachytherapy and approaches for improved system performance. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Callan, J.R.; Kelly, R.T.; Quinn, M.L. [Pacific Science and Engineering Group, San Diego, CA (United States)] [and others

    1995-05-01

    Remote Afterloading Brachytherapy (RAB) is a medical process used in the treatment of cancer. RAB uses a computer-controlled device to remotely insert and remove radioactive sources close to a target (or tumor) in the body. Some RAB problems affecting the radiation dose to the patient have been reported and attributed to human error. To determine the root cause of human error in the RAB system, a human factors team visited 23 RAB treatment sites in the US The team observed RAB treatment planning and delivery, interviewed RAB personnel, and performed walk-throughs, during which staff demonstrated the procedures and practices used in performing RAB tasks. Factors leading to human error in the RAB system were identified. The impact of those factors on the performance of RAB was then evaluated and prioritized in terms of safety significance. Finally, the project identified and evaluated alternative approaches for resolving the safety significant problems related to human error.

  4. Dosimetry audit on the accuracy of 192Ir brachytherapy source strength determinations in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson Tedgren, Aasa

    2007-11-15

    The absorbed dose delivered to the patient in brachytherapy is directly proportional to the source strength in terms of the reference air-kerma rate (RAKR). Verification of this quantity by the hospitals is widely recognized as an important part of a quality assurance program. An external audit was performed on behalf of the Secondary Standard Dosimetry Laboratory at the Swedish Radiation Protection Authority (SSI). The aim was to investigate how accurately the source-strength in 192Ir brachytherapy is determined at Swedish hospitals. The SSI reference well-type ion chamber and calibrated equipment were used to measure the RAKR of an 192Ir source in each of the 14 Swedish afterloading units. Comparisons with values determined by vendors and hospitals were made. Agreement in values of RAKR as determined by SSI, hospitals and vendors were in all cases within the +-3% uncertainty (at a coverage factor of k=2), typically guaranteed by the vendors. The good agreement reflects the robustness and easy handling of well-type chambers designed for brachytherapy in use by all Swedish hospitals. The 192Ir calibration service planned at SSI will solve the hospitals current problem with recalibration of equipment. SSI can also advise hospitals to follow the IAEA recommendations for measurement techniques and maintenance of equipment. It is worthwhile for the hospitals to establish their own ratio (or deviation) with the vendor and follow it as function of time. Such a mean-ratio embeds systematic differences of various origins and have a lower uncertainty than has the RAKR alone, making it useful for early detection of problems with equipment or routines. SSI could also define requirements for the agreement between source strengths as determined by hospitals and vendors and couple this to an action plan, dependent on level of disagreement, and some kind of reporting to SSI

  5. Recognition of Radiological Protection of Ward Staff after Brachytherapy for Malignant Tumor with Radioiodine Seeds

    Directory of Open Access Journals (Sweden)

    HU Shu

    2016-02-01

    Full Text Available Through radiation measurement of the patients after brachytherapy with radioiodine seeds for malignant tumor at different distances and shielding condition, the importance, optimization and individualization of the radiological protection are well recognized. The 35 patients were randomly selected in the minimally invasive interventional ward of Peking University Shenzhen Hospital who underwent brachytherapy for malignant tumor with radioiodine seeds. Within 2 hours after the brachytherapy, the radiation of the patients without shielding, with 0.25 mmPb and 0.5 mmPb shielding were detected by an x-γ ray detector at different distances (equivalent dose rate. The results were analysed by SPSS19.0 t test. Annual equivalent dose was calculated by the average close contact time (two hours everyone per day. The average annual equivalent dose of the 35 patients without shielding was below 20 mSv at 0.5 meter, close to the public limit 1 mSv at 2 meters and equivalent to the background at 4 meters. Under 0.25 mmPb shielding, 6 patients’ radiation was still above the pubic limit, although the average radiation of the 35 patients was below the pubic limit; under 0.5 mmPb shielding, all patients’ radiation was nearly equivalent to the background at 0 meter. The results showed that among the time, distance and shielded protection, the individual radiological protection was especially important. The 0.25 mmPb lead cushion was the most commonly used shield. The 0.5 mmPb lead cushion also should be used in case of the large number of radioiodine seeds implantation and/or more superficial implant site, so as to ensure the individualization and optimization in radiological protection.

  6. CT-guided brachytherapy of prostate cancer: reduction of effective dose from X-ray examination

    Science.gov (United States)

    Sanin, Dmitriy B.; Biryukov, Vitaliy A.; Rusetskiy, Sergey S.; Sviridov, Pavel V.; Volodina, Tatiana V.

    2014-03-01

    Computed tomography (CT) is one of the most effective and informative diagnostic method. Though the number of CT scans among all radiographic procedures in the USA and European countries is 11% and 4% respectively, CT makes the highest contribution to the collective effective dose from all radiographic procedures, it is 67% in the USA and 40% in European countries [1-5]. Therefore it is necessary to understand the significance of dose value from CT imaging to a patient . Though CT dose from multiple scans and potential risk is of great concern in pediatric patients, this applies to adults as well. In this connection it is very important to develop optimal approaches to dose reduction and optimization of CT examination. International Commission on Radiological Protection (ICRP) in its publications recommends radiologists to be aware that often CT image quality is higher than it is necessary for diagnostic confidence[6], and there is a potential to reduce the dose which patient gets from CT examination [7]. In recent years many procedures, such as minimally invasive surgery, biopsy, brachytherapy and different types of ablation are carried out under guidance of computed tomography [6;7], and during a procedures multiple CT scans focusing on a specific anatomic region are performed. At the Clinics of MRRC different types of treatment for patients with prostate cancer are used, incuding conformal CT-guided brachytherapy, implantation of microsources of I into the gland under guidance of spiral CT [8]. So, the purpose of the study is to choose optimal method to reduce radiation dose from CT during CT-guided prostate brachytherapy and to obtain the image of desired quality.

  7. Accuracy Evaluation of Oncentra™ TPS in HDR Brachytherapy of Nasopharynx Cancer Using EGSnrc Monte Carlo Code

    Directory of Open Access Journals (Sweden)

    Hadad K

    2015-03-01

    Full Text Available Background: HDR brachytherapy is one of the commonest methods of nasopharyngeal cancer treatment. In this method, depending on how advanced one tumor is, 2 to 6 Gy dose as intracavitary brachytherapy is prescribed. Due to high dose rate and tumor location, accuracy evaluation of treatment planning system (TPS is particularly important. Common methods used in TPS dosimetry are based on computations in a homogeneous phantom. Heterogeneous phantoms, especially patient-specific voxel phantoms can increase dosimetric accuracy. Materials and Methods: In this study, using CT images taken from a patient and ctcreate-which is a part of the DOSXYZnrc computational code, patient-specific phantom was made. Dose distribution was plotted by DOSXYZnrc and compared with TPS one. Also, by extracting the voxels absorbed dose in treatment volume, dosevolume histograms (DVH was plotted and compared with Oncentra™ TPS DVHs. Results: The results from calculations were compared with data from Oncentra™ treatment planning system and it was observed that TPS calculation predicts lower dose in areas near the source, and higher dose in areas far from the source relative to MC code. Absorbed dose values in the voxels also showed that TPS reports D90 value is 40% higher than the Monte Carlo method. Conclusion: Today, most treatment planning systems use TG-43 protocol. This protocol may results in errors such as neglecting tissue heterogeneity, scattered radiation as well as applicator attenuation. Due to these errors, AAPM emphasized departing from TG-43 protocol and approaching new brachytherapy protocol TG-186 in which patient-specific phantom is used and heterogeneities are affected in dosimetry

  8. Oxygenation status of cervical carcinomas before and during spinal anesthesia for application of brachytherapy

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    Weitmann, H.D.; Knocke, T.H.; Poetter, R. [Dept. of Radiotherapy and Radiobiology, Univ. of Vienna, General Hospital of Vienna (Austria); Gustorff, B. [Dept. of Anesthesia and General Intensive Care B, Univ. of Vienna, General Hospital of Vienna (Austria); Vaupel, P. [Inst. of Physiology and Pathophysiology, Univ. of Mainz (Germany)

    2003-09-01

    Background and Purpose: To date, no information is available concerning the impact of spinal anesthesia on the oxygenation status of carcinomas of the uterine cervix. The aim of this study was therefore to determine the influence of spinal anesthesia on the oxygenation status of cervical carcinomas. Patients and Methods: In ten patients with cervical carcinoma who received spinal anesthesia for a first application of brachytherapy, intratumoral pO{sub 2} measurements (pO{sub 2} histography system, Eppendorf-Netheler-Hinz, Hamburg, Germany) were performed. Systemic parameters were documented prior to and during spinal anesthesia. Patients breathed room air spontaneously. For further evaluation, all intratumoral pO{sub 2} values were pooled, and overall median pO{sub 2} values and fractions of hypoxic pO{sub 2} values {<=} 5 mm Hg were calculated. Overall median pO{sub 2} values in the subcutis were also calculated. Results: There were no significant changes of systemic parameters, median subcutaneous pO{sub 2} values, median intratumoral pO{sub 2} values, and the fractions of hypoxic pO{sub 2} values {<=} 5 mm Hg in the tumor upon administration of spinal anesthesia. The variability of measured pO{sub 2} values increased during spinal anesthesia, although substantial changes in the oxygenation status were only seen in individual cases (n = 2). Conclusion: This study shows for the first time that the oxygenation status of cervical carcinomas, in general, is not influenced by spinal anesthesia prior to application of brachytherapy. To conclude, the data presented suggest that reliable pO{sub 2} measurements can be performed under spinal anesthesia. At the same time, since no substantial changes in tumor oxygenation were observed, spinal anesthesia should not affect the O{sub 2}-related efficacy of high-dose-rate brachytherapy. (orig.)

  9. Quality Assurance of Multifractionated Pelvic Interstitial Brachytherapy for Postoperative Recurrences of Cervical Cancers: A Prospective Study

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    Shukla, Pragya [Department of Radiation Oncology and Medical Physics, Tata Memorial Hospital, Tata Memorial Centre, Mumbai, Maharashtra (India); Chopra, Supriya, E-mail: schopra@actrec.gov.in [Department of Radiation Oncology, Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre, Mumbai, Maharashtra (India); Engineer, Reena; Mahantshetty, Umesh [Department of Radiation Oncology and Medical Physics, Tata Memorial Hospital, Tata Memorial Centre, Mumbai, Maharashtra (India); Paul, Siji Nojin; Phurailatpam, Reena [Department of Radiation Oncology, Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre, Mumbai, Maharashtra (India); SV, Jamema; Shrivastava, Shyam K. [Department of Radiation Oncology and Medical Physics, Tata Memorial Hospital, Tata Memorial Centre, Mumbai, Maharashtra (India)

    2012-03-15

    Purpose: To evaluate three-dimensional needle displacements during multifractionated interstitial brachytherapy (BT) for cervical cancers. Methods and Materials: Patients scheduled to undergo pelvic interstitial BT for postoperative and or postradiation vault recurrences were included from November 2009 to December 2010. All procedures were performed under spinal anesthesia. Postprocedure BT planning CT scans were obtained with patients in supine position with arms on the chest (interslice thickness of 3 mm). Thereafter, verification CT was repeated at every alternate fraction. Needle displacements were measured in reference to a relocatable bony point. The mean cranial, caudal, anteroposterior, and mediolateral displacements were recorded. Statistical significance of mean interfraction displacements was evaluated with Wilcoxon Test. Results: Twenty patients were included. Seventeen received boost BT (20 Gy/5 fractions/3 days) after external radiation, three received radical BT alone (36 Gy/9 fractions/5-8 days). An average of three scans (range, 2-3) were available per patient, and 357 needle displacements were analyzed. For the entire study cohort, the average of mean needle displacement was 2.5 mm (range, 0-7.4), 17.4 mm (range, 0-27.9), 1.7 mm (range, 0-6.7), 2.1 mm (range, 0-9.5), 1.7 mm (range, 0-9.3), and 0.6 mm (range, 0-7.8) in cranial, caudal, anterior, posterior, right, and left directions, respectively. The mean displacement in the caudal direction was higher between Days 1 and 2 than that between Days 2 and 3 (13.4 mm vs. 3.8 mm; p = 0.01). The average caudal displacements were no different between reirradiation and boost cohort (15.2 vs. 17.8 mm). Conclusions: Clinically significant caudal displacements occur during multifractionated pelvic brachytherapy. Optimal margins need to be incorporated while preplanning brachytherapy to account for interfraction displacements.

  10. Understanding the Relationship between Interactive Optimisation and Visual Analytics in the Context of Prostate Brachytherapy.

    Science.gov (United States)

    Liu, Jie; Dwyer, Tim; Marriott, Kim; Millar, Jeremy; Haworth, Annette

    2017-08-29

    The fields of operations research and computer science have long sought to find automatic solver techniques that can find high-quality solutions to difficult real-world optimisation problems. The traditional workflow is to exactly model the problem and then enter this model into a general-purpose "black-box" solver. In practice, however, many problems cannot be solved completely automatically, but require a "human-in-the-loop" to iteratively refine the model and give hints to the solver. In this paper, we explore the parallels between this interactive optimisation workflow and the visual analytics sense-making loop. We assert that interactive optimisation is essentially a visual analytics task and propose a problem-solving loop analogous to the sense-making loop. We explore these ideas through an in-depth analysis of a use-case in prostate brachytherapy, an application where interactive optimisation may be able to provide significant assistance to practitioners in creating prostate cancer treatment plans customised to each patient's tumour characteristics. However, current brachytherapy treatment planning is usually a careful, mostly manual process involving multiple professionals. We developed a prototype interactive optimisation tool for brachytherapy that goes beyond current practice in supporting focal therapy - targeting tumour cells directly rather than simply seeking coverage of the whole prostate gland. We conducted semi-structured interviews, in two stages, with seven radiation oncology professionals in order to establish whether they would prefer to use interactive optimisation for treatment planning and whether such a tool could improve their trust in the novel focal therapy approach and in machine generated solutions to the problem.

  11. Prognostic Importance of Small Prostate Size in Men Receiving Definitive Prostate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Taira, Al V. [Western Radiation Oncology, Mountain View, California (United States); Merrick, Gregory S., E-mail: gmerrick@urologicresearchinstitute.org [Schiffler Cancer Center, Wheeling Jesuit University, Wheeling, West Virginia (United States); Galbreath, Robert W.; Butler, Wayne M. [Schiffler Cancer Center, Wheeling Jesuit University, Wheeling, West Virginia (United States); Adamovich, Edward [Department of Pathology, Wheeling Hospital, Wheeling, West Virginia (United States); Wallner, Kent E. [Puget Sound Healthcare Corporation, Group Health Cooperative, University of Washington, Seattle, Washington (United States)

    2012-10-01

    Purpose: To assess whether small prostate size is an adverse prognostic factor in men undergoing brachytherapy in the same manner in which it seems to be for men undergoing radical prostatectomy. Methods and Materials: From April 1995 to June 2008, 2024 patients underwent brachytherapy by a single brachytherapist. Median follow-up was 7.4 years. The role of small prostate size ({<=}20 cm{sup 3}) as a prognostic factor for biochemical progression-free survival, cause-specific survival, and all-cause mortality was investigated. The differences in survival between men with small and larger prostates were compared using Kaplan-Meier curves and log-rank tests. Results: Median prostate size for the entire cohort was 32.7 cm{sup 3}. For the 167 men with small prostates, median prostate size was 17.4 cm{sup 3}. There was no difference in biochemical progression-free survival (95.2% vs 96.2%, P=.603), cause-specific survival (97.7% vs 98.3%, P=.546), or all-cause mortality (78.0% vs 77.2%, P=.838) at 10 years for men with small prostates compared with men with larger prostates. On univariate and multivariate analysis, small prostate size was not associated with any of the primary outcome measures. Conclusion: Men with small prostates treated with brachytherapy have excellent outcomes and are at no higher risk of treatment failure than men with larger glands. High-quality implants with adequate margins seem sufficient to address the increased adverse risk factors associated with small prostate size.

  12. Predictive Factors and Management of Rectal Bleeding Side Effects Following Prostate Cancer Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Price, Jeremy G. [Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, New York (United States); Stone, Nelson N. [Department of Urology, Icahn School of Medicine at Mount Sinai, New York, New York (United States); Stock, Richard G., E-mail: Richard.Stock@mountsinai.org [Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, New York (United States)

    2013-08-01

    Purpose: To report on the incidence, nature, and management of rectal toxicities following individual or combination brachytherapy following treatment for prostate cancer over a 17-year period. We also report the patient and treatment factors predisposing to acute ≥grade 2 proctitis. Methods and Materials: A total of 2752 patients were treated for prostate cancer between October 1990 and April 2007 with either low-dose-rate brachytherapy alone or in combination with androgen depletion therapy (ADT) or external beam radiation therapy (EBRT) and were followed for a median of 5.86 years (minimum 1.0 years; maximum 19.19 years). We investigated the 10-year incidence, nature, and treatment of acute and chronic rectal toxicities following BT. Using univariate, and multivariate analyses, we determined the treatment and comorbidity factors predisposing to rectal toxicities. We also outline the most common and effective management for these toxicities. Results: Actuarial risk of ≥grade 2 rectal bleeding was 6.4%, though notably only 0.9% of all patients required medical intervention to manage this toxicity. The majority of rectal bleeding episodes (72%) occurred within the first 3 years following placement of BT seeds. Of the 27 patients requiring management for their rectal bleeding, 18 underwent formalin treatment and nine underwent cauterization. Post-hoc univariate statistical analysis revealed that coronary artery disease (CAD), biologically effective dose, rectal volume receiving 100% of the prescription dose (RV100), and treatment modality predict the likelihood of grade ≥2 rectal bleeding. Only CAD, treatment type, and RV100 fit a Cox regression multivariate model. Conclusions: Low-dose-rate prostate brachytherapy is very well tolerated and rectal bleeding toxicities are either self-resolving or effectively managed by medical intervention. Treatment planning incorporating adjuvant ADT while minimizing RV100 has yielded the best toxicity-free survival following

  13. Gamma knife radiosurgery for uveal melanoma ineligible for brachytherapy by the Collaborative Ocular Melanoma Study criteria

    Directory of Open Access Journals (Sweden)

    Nicola G Ghazi

    2008-09-01

    Full Text Available Nicola G Ghazi1, Christopher S Ketcherside1, Jason Sheehan2, Brian P Conway11Department of Ophthalmology and 2Neurosurgery, University of Virginia Health System, Charlottesville, VA, USAPurpose: To report outcomes of Gamma Knife radiosurgery (GKRS in treating uveal melanoma lesions ineligible for standard brachytherapy.Methods: A retrospective interventional case series of uveal melanoma patients treated with GKRS between 1996 and 2004 was performed. The main outcome measures were local tumor control, metastasis, and death.Results: Four patients with uveal melanoma treated with GKS were identified. Three tumors involved the ciliary body and one was macular with its border within 2 mm of the optic disc. Adequate globe stabilization was achieved by retrobulbar anesthesia in all cases. Pretreatment mean visual acuity was 20/30. Tumor volume as determined by magnetic resonance imaging ranged from 0.05 to 0.30 cc. Ultrasonographic greatest tumor diameter and height ranged from 11 to 18 mm (mean 14.5 mm and 2.9 to 4.5 mm (mean 3.6 mm, respectively. The peripheral dose varied from 16.5 to 30 Gray. Local tumor control was achieved in all cases over a follow up period of 6 to 96 months. Mean final visual acuity was 20/50. One eye was enucleated for neovascular glaucoma and one patient died from liver and lung metastasis.Conclusions: GKRS for uveal melanoma appears to be safe and effective. The metastasis and mortality rates appear to be comparable to those following brachytherapy and enucleation. Moreover, local tumor control and enucleation rates are similar to those following brachytherapy. The findings in this small series suggest a role for GKRS in the treatment of selected cases of uveal melanomas.Keywords: gamma knife radiosurgery, radiation therapy, uveal melanoma

  14. A method for verification of treatment times for high-dose-rate intraluminal brachytherapy treatment

    Directory of Open Access Journals (Sweden)

    Muhammad Asghar Gadhi

    2016-06-01

    Full Text Available Purpose: This study was aimed to increase the quality of high dose rate (HDR intraluminal brachytherapy treatment. For this purpose, an easy, fast and accurate patient-specific quality assurance (QA tool has been developed. This tool has been implemented at Bahawalpur Institute of Nuclear Medicine and Oncology (BINO, Bahawalpur, Pakistan.Methods: ABACUS 3.1 Treatment planning system (TPS has been used for treatment planning and calculation of total dwell time and then results were compared with the time calculated using the proposed method. This method has been used to verify the total dwell time for different rectum applicators for relevant treatment lengths (2-7 cm and depths (1.5-2.5 cm, different oesophagus applicators of relevant treatment lengths (6-10 cm and depths (0.9 & 1.0 cm, and a bronchus applicator for relevant treatment lengths (4-7.5 cm and depth (0.5 cm.Results: The average percentage differences between treatment time TM with manual calculation and as calculated by the TPS is 0.32% (standard deviation 1.32% for rectum, 0.24% (standard deviation 2.36% for oesophagus and 1.96% (standard deviation 0.55% for bronchus, respectively. These results advocate that the proposed method is valuable for independent verification of patient-specific treatment planning QA.Conclusion: The technique illustrated in the current study is an easy, simple, quick and useful for independent verification of the total dwell time for HDR intraluminal brachytherapy. Our method is able to identify human error-related planning mistakes and to evaluate the quality of treatment planning. It enhances the quality of brachytherapy treatment and reliability of the system.

  15. Comparison of Dose When Prescribed to Point A and Point H for Brachytherapy in Cervical Cancer

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    Gang, Ji Hyeong; Gim, Il Hwan; Hwang, Seon Boong; Kim, Woong; Im, Hyeong Seo; Gang, Jin Mook; Gim, Gi Hwan; Lee, Ah Ram [Dept. of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seou (Korea, Republic of)

    2012-09-15

    The purpose of this study is to compare plans prescribed to point A with these prescribed to point H recommended by ABS (American Brachytherapy Society) in high dose rate intracavitary brachytherapy for cervical carcinoma. This study selected 103 patients who received HDR (High Dose Rate) brachytherapy using tandem and ovoids from March 2010 to January 2012. Point A, bladder point, and rectal point conform with Manchester System. Point H conforms with ABS recommendation. Also Sigmoid colon point, and vagina point were established arbitrarily. We examined distance between point A and point H. The percent dose at point A was calculated when 100% dose was prescribed to point H. Additionally, the percent dose at each reference points when dose is prescribed to point H and point A were calculated. The relative dose at point A was lower when point H was located inferior to point A. The relative doses at bladder, rectal, sigmoid colon, and vagina points were higher when point H was located superior to point A, and lower when point H was located inferior to point A. This study found out that as point H got located much superior to point A, the absorbed dose of surrounding normal organs became higher, and as point H got located much inferior to point A, the absorbed dose of surrounding normal organs became lower. This differences dose not seem to affect the treatment. However, we suggest this new point is worth being considered for the treatment of HDR if dose distribution and absorbed dose at normal organs have large differences between prescribed to point A and H.

  16. Dosimetry audits in Brazil for {sup 192}Ir high dose rate