Comparison of Computed Tomography– and Magnetic Resonance Imaging–based Clinical Target Volume Contours at Brachytherapy for Cervical Cancer

International Nuclear Information System (INIS)

Swanick, Cameron W.; Castle, Katherine O.; Vedam, Sastry; Munsell, Mark F.; Turner, Lehendrick M.; Rauch, Gaiane M.; Jhingran, Anuja; Eifel, Patricia J.; Klopp, Ann H.

2016-01-01

Purpose: We prospectively compared computed tomography (CT)– and magnetic resonance imaging (MRI)–based high-risk clinical target volume (HR-CTV) contours at the time of brachytherapy for cervical cancer in an effort to identify patients who might benefit most from MRI-based planning. Methods and Materials: Thirty-seven patients who had undergone a pretreatment diagnostic MRI scan were included in the analysis. We delineated the HR-CTV on the brachytherapy CT and brachytherapy MRI scans independently for each patient. We then calculated the absolute volumes for each HR-CTV and the Dice coefficient of similarity (DC, a measure of spatial agreement) for the HR-CTV contours. We identified the clinical and tumor factors associated with (1) a discrepancy in volume between the CT HR-CTV and MRI HR-CTV contours; and (2) DC. The mean values were compared using 1-way analysis of variance or paired or unpaired t tests, as appropriate. Simple and multivariable linear regression analyses were used to model the effects of covariates on the outcomes. Results: Patients with International Federation of Gynecology and Obstetrics stage IB to IVA cervical cancer were treated with intracavitary brachytherapy using tandem and ovoid (n=33) or tandem and cylinder (n=4) applicators. The mean CT HR-CTV volume (44.1 cm"3) was larger than the mean MRI HR-CTV volume (35.1 cm"3; P 5 cm and parametrial invasion on MRI at diagnosis and for those with a high BMI.

Validation of MRI to TRUS registration for high-dose-rate prostate brachytherapy.

Science.gov (United States)

Poulin, Eric; Boudam, Karim; Pinter, Csaba; Kadoury, Samuel; Lasso, Andras; Fichtinger, Gabor; Ménard, Cynthia

The objective of this study was to develop and validate an open-source module for MRI to transrectal ultrasound (TRUS) registration to support tumor-targeted prostate brachytherapy. In this study, 15 patients with prostate cancer lesions visible on multiparametric MRI were selected for the validation. T2-weighted images with 1-mm isotropic voxel size and diffusion weighted images were acquired on a 1.5T Siemens imager. Three-dimensional (3D) TRUS images with 0.5-mm slice thickness were acquired. The investigated registration module was incorporated in the open-source 3D Slicer platform, which can compute rigid and deformable transformations. An extension of 3D Slicer, SlicerRT, allows import of and export to DICOM-RT formats. For validation, similarity indices, prostate volumes, and centroid positions were determined in addition to registration errors for common 3D points identified by an experienced radiation oncologist. The average time to compute the registration was 35 ± 3 s. For the rigid and deformable registration, respectively, Dice similarity coefficients were 0.87 ± 0.05 and 0.93 ± 0.01 while the 95% Hausdorff distances were 4.2 ± 1.0 and 2.2 ± 0.3 mm. MRI volumes obtained after the rigid and deformable registration were not statistically different (p > 0.05) from reference TRUS volumes. For the rigid and deformable registration, respectively, 3D distance errors between reference and registered centroid positions were 2.1 ± 1.0 and 0.4 ± 0.1 mm while registration errors between common points were 3.5 ± 3.2 and 2.3 ± 1.1 mm. Deformable registration was found significantly better (p < 0.05) than rigid registration for all parameters. An open-source MRI to TRUS registration platform was validated for integration in the brachytherapy workflow. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

MO-B-BRC-04: MRI-Based Prostate HDR

International Nuclear Information System (INIS)

Mourtada, F.

2016-01-01

Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions

MO-B-BRC-04: MRI-Based Prostate HDR

Energy Technology Data Exchange (ETDEWEB)

Mourtada, F. [Christiana Care Hospital (United States)

2016-06-15

Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.

MRI-Guided High–Dose-Rate Intracavitary Brachytherapy for Treatment of Cervical Cancer: The University of Pittsburgh Experience

Energy Technology Data Exchange (ETDEWEB)

Gill, Beant S.; Kim, Hayeon; Houser, Christopher J. [Department of Radiation Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States); Kelley, Joseph L.; Sukumvanich, Paniti; Edwards, Robert P.; Comerci, John T.; Olawaiye, Alexander B.; Huang, Marilyn; Courtney-Brooks, Madeleine [Department of Gynecologic Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States); Beriwal, Sushil, E-mail: beriwals@upmc.edu [Department of Radiation Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States)

2015-03-01

Purpose: Image-based brachytherapy is increasingly used for gynecologic malignancies. We report early outcomes of magnetic resonance imaging (MRI)-guided brachytherapy. Methods and Materials: Consecutive patient cases with FIGO stage IB1 to IVA cervical cancer treated at a single institution were retrospectively reviewed. All patients received concurrent cisplatin with external beam radiation therapy along with interdigitated high–dose-rate intracavitary brachytherapy. Computed tomography or MRI was completed after each application, the latter acquired for at least 1 fraction. High-risk clinical target volume (HRCTV) and organs at risk were identified by Groupe Européen de Curiethérapie and European SocieTy for Radiotherapy and Oncology guidelines. Doses were converted to equivalent 2-Gy doses (EQD{sub 2}) with planned HRCTV doses of 75 to 85 Gy. Results: From 2007 to 2013, 128 patients, median 52 years of age, were treated. Predominant characteristics included stage IIB disease (58.6%) with a median tumor size of 5 cm, squamous histology (82.8%), and no radiographic nodal involvement (53.1%). Most patients (67.2%) received intensity modulated radiation therapy (IMRT) at a median dose of 45 Gy, followed by a median brachytherapy dose of 27.5 Gy (range, 25-30 Gy) in 5 fractions. At a median follow up of 24.4 months (range, 2.1-77.2 months), estimated 2-year local control, disease-free survival, and cancer-specific survival rates were 91.6%, 81.8%, and 87.6%, respectively. Predictors of local failure included adenocarcinoma histology (P<.01) and clinical response at 3 months (P<.01). Among the adenocarcinoma subset, receiving HRCTV D{sub 90} EQD{sub 2} ≥84 Gy was associated with improved local control (2-year local control rate 100% vs 54.5%, P=.03). Grade 3 or greater gastrointestinal or genitourinary late toxicity occurred at a 2-year actuarial rate of 0.9%. Conclusions: This study constitutes one of the largest reported series of MRI

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...

SU-E-J-226: Efficient Use of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) for Cervical-Cancer Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Damato, A; Bhagwat, M; Buzurovic, I; Cormack, R; Lee, L; Viswanathan, A [Harvard Medical School, Boston, MA (United States)

2015-06-15

Purpose: To investigate image modality selection in an environment with limited access to interventional MRI for image-guided high-dose-rate cervical-cancer brachytherapy. Methods: Records of all cervical-cancer patients treated with brachytherapy between 1/2013 and 8/2014 were analyzed. Insertions were performed under CT guidance (CT group) or with >1 fraction under 3T MR guidance (MRI group; subMRI includes only patients who also had a CT-guided insertion). Differences between groups in clinical target volume (CTV), disease stage (I/II or III/IV), number of patients with or without interstitial needles, and CTV D90 were investigated. Statistical significance was evaluated with the Student T test and Fisher test (p <0.05). Results: 46 cervical-cancer patients were included (16 MRI [3 subMRI], 30 CT). CTV: overall, 55±53 cm3; MRI, 81±61 cm3; CT, 42±44 cm3 (p = 0.017). Stage: overall, 24 I/II and 22 III/IV; MRI, 3 I/II and 13 III/IV; CT, 21 I/II and 9 III/IV (p = 0.002). Use of needles: overall, 26 without and 20 with; MRI, 5 without and 11 with; CT, 21 without and 9 with (p = 0.015). CTV D90: overall, 82±5 Gy; MRI, 81±6 Gy; CT, 82±5 Gy (p = 0.78). SubMRI: CTV and D90 (as % of nominal fraction dose) were 23±6 cm3 and 124±3% for MRI-guided insertions and 21±5 cm3 (p = 0.83) and 106±12% (p = 0.15) for CT-guided insertions. Conclusion: Statistically significant differences in patient population indicate preferential use of MRI for patients with high-stage disease and large residual CTVs requiring the use of interstitial needles. CTV D90 was similar between groups, despite the difference in patient selection. For patients who underwent both CT and MRI insertions, a larger MR CTV D90 and similar CTVs between insertions were observed. While MRI is generally preferable to CT, MRI selection can be optimized in environments without a dedicated MRI brachytherapy suite. This work was partially funded by the NIH R21 CA167800 (PI: Viswanathan; aviswanathan@partners.org)

SU-E-J-226: Efficient Use of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) for Cervical-Cancer Brachytherapy

International Nuclear Information System (INIS)

Damato, A; Bhagwat, M; Buzurovic, I; Cormack, R; Lee, L; Viswanathan, A

2015-01-01

Purpose: To investigate image modality selection in an environment with limited access to interventional MRI for image-guided high-dose-rate cervical-cancer brachytherapy. Methods: Records of all cervical-cancer patients treated with brachytherapy between 1/2013 and 8/2014 were analyzed. Insertions were performed under CT guidance (CT group) or with >1 fraction under 3T MR guidance (MRI group; subMRI includes only patients who also had a CT-guided insertion). Differences between groups in clinical target volume (CTV), disease stage (I/II or III/IV), number of patients with or without interstitial needles, and CTV D90 were investigated. Statistical significance was evaluated with the Student T test and Fisher test (p <0.05). Results: 46 cervical-cancer patients were included (16 MRI [3 subMRI], 30 CT). CTV: overall, 55±53 cm3; MRI, 81±61 cm3; CT, 42±44 cm3 (p = 0.017). Stage: overall, 24 I/II and 22 III/IV; MRI, 3 I/II and 13 III/IV; CT, 21 I/II and 9 III/IV (p = 0.002). Use of needles: overall, 26 without and 20 with; MRI, 5 without and 11 with; CT, 21 without and 9 with (p = 0.015). CTV D90: overall, 82±5 Gy; MRI, 81±6 Gy; CT, 82±5 Gy (p = 0.78). SubMRI: CTV and D90 (as % of nominal fraction dose) were 23±6 cm3 and 124±3% for MRI-guided insertions and 21±5 cm3 (p = 0.83) and 106±12% (p = 0.15) for CT-guided insertions. Conclusion: Statistically significant differences in patient population indicate preferential use of MRI for patients with high-stage disease and large residual CTVs requiring the use of interstitial needles. CTV D90 was similar between groups, despite the difference in patient selection. For patients who underwent both CT and MRI insertions, a larger MR CTV D90 and similar CTVs between insertions were observed. While MRI is generally preferable to CT, MRI selection can be optimized in environments without a dedicated MRI brachytherapy suite. This work was partially funded by the NIH R21 CA167800 (PI: Viswanathan; aviswanathan@partners.org)

Fiber Bragg gratings-based sensing for real-time needle tracking during MR-guided brachytherapy

NARCIS (Netherlands)

Borot, Maxence; Denis de Senneville, Baudouin; Maenhout, Metha; Lagendijk, JJW; van Vulpen, Marco; Hautvast, Gilion; Binnekamp, Dirk; Moerland, Rien

2016-01-01

PURPOSE: The development of MR-guided high dose rate (HDR) brachytherapy is under investigation due to the excellent tumor and organs at risk visualization of MRI. However, MR-based localization of needles (including catheters or tubes) has inherently a low update rate and the required image

MRI-Based Evaluation of the Vaginal Cuff in Brachytherapy Planning: Are We Missing the Target?

Energy Technology Data Exchange (ETDEWEB)

Chapman, Christina Hunter; Prisciandaro, Joann I. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Maturen, Katherine E. [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Cao, Yue [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan (United States); Balter, James M. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan (United States); McLean, Karen [Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, Michigan (United States); Jolly, Shruti, E-mail: shrutij@med.umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)

2016-06-01

Purpose: Although recurrences and toxicity occur after vaginal cuff (VC) brachytherapy, little is known about dosimetry due to the inability to clearly visualize the VC on computed tomography (CT). T2-weighted (T2W) magnetic resonance imaging (MRI) is superior to CT in this setting, and we hypothesized that it could provide previously unascertainable dosimetric information. Methods and Materials: In a cohort of 32 patients who underwent cylinder-based brachytherapy for endometrial cancer with available MR simulation images, the VC was retrospectively contoured on T2W images, and cases were replanned to treat the upper VC to a dose of 7 Gy/fraction prescribed to 5 mm. Relevant dose-volume parameters for the VC were calculated. Results: T2W MRI identified significant underdosing not observed on CT or T1-weighted imaging. Over two-thirds (69%) of patients had at least 1 cm{sup 3} of VC that received less than 75% of the prescription dose and half (50%) of patients had a least 1 cm{sup 3} of VC that received less than 50% of the prescription dose. The mean minimum point dose to the VC was 2.4 Gy, or 34% of the intended prescription dose (range: 0.53-6.4 Gy). Conclusions: We identified previously unreported VC underdosing in over two-thirds of our patients, with most of these patients having volumes of undistended VC that received less than half of the prescription dose. The maximum dimension was along the craniocaudal axis in some patients or left-right/anterior-posterior axis in others, suggesting that suture material may be restricting access to the vaginal apex and that alternative applicators may be needed when the diameter of the apex is larger than the introitus. Additional follow-up will be needed to determine whether underdosing is associated with isolated VC failure or whether low failure rates across the cohort suggest that some patients are being exposed to excessive dose and unnecessary risk of toxicity.

CT or MRI for image-based brachytherapy in cervical cancer

International Nuclear Information System (INIS)

Krishnatry, R.; Patel, F.D.; Singh, P.; Sharma, S.C.; Oinam, A.S.; Shukla, A.K.

2012-01-01

The objective of this study was to compare volumes and doses of tumour and organs at risk with computed tomography vs. magnetic resonance imaging in cervical cancer brachytherapy. Seventeen previously untreated patients with cervical cancer suitable for radical treatment were included. All patients underwent brachytherapy using a magnetic resonance imaging-compatible applicator followed by both computed tomography and magnetic resonance imaging. The tumour and organs at risk (bladder, rectum, sigmoid and intestines) were contoured on computed tomography using only clinical findings and on magnetic resonance imaging using GEC-ESTRO guidelines. The volume and doses for tumour and organs at risk were evaluated using two-sided t-test. When magnetic resonance imaging information is not included in contouring on computed tomography images, there is significant underestimation of tumour height and overestimation of the width (P 100 , D 90 and D 100 for high- and intermediate-risk clinical target volume in computed tomography and magnetic resonance imaging. The volumes and doses to 0.1, 1 and 2 cc for organs at risk were also similar. Magnetic resonance imaging remains the gold standard for tumour delineation, but computed tomography with clinical information can give comparable results, which need to be studied further. Computed tomography-based contouring can be used comfortably for delineation of organs at risk. (author)

[Brachytherapy of brainstem tumors].

Science.gov (United States)

Julow, Jenö; Viola, Arpád; Major, Tibor; Valálik, István; Sági, Sarolta; Mangel, László; Kovács, Rita Beáta; Repa, Imre; Bajzik, Gábor; Németh, György

2004-01-20

The optimal therapy of brain stem tumours of different histopathology determines the expected length of survival. Authors report 125Iodine interstitial irradiation of brain stem tumours with stereotactic brachytherapy. Two patients having brain stem tumours were suffering from glioma or from metastases of a carcinoma. In Case 1 the tumour volume was 1.98 cm3 at the time of planning interstitial irradiation. The control MRI examination performed at 42 months post-op showed a postirradiation cyst size of 5.73 cm3 indicating 65.5% shrinkage. In Case 2 the shrinkage was more apparent as the tumour volume measured on the control MRI at 8 months post-op was only 0.16 cm3 indicating 97.4% shrinkage of the 6.05 cm3 target volume at the time of brachytherapy with the metastasis practically disappearing. Quick access to histopathological results of the stereotactic intraoperative biopsy made it possible to carry out the 125Iodine stereotactic brachytherapy immediately after the biopsy, resulting in less inconvenience for patients of a second possible intervention. The control MRI scans show significant shrinkage of tumours in both patients. The procedure can be performed as a biopsy. The CT and image fusion guided 125Iodine stereotactic brachytherapy can be well planned dosimetrically and is surgically precise.

A Fabry-Perot Interferometry Based MRI-Compatible Miniature Uniaxial Force Sensor for Percutaneous Needle Placement

OpenAIRE

Shang, Weijian; Su, Hao; Li, Gang; Furlong, Cosme; Fischer, Gregory S.

2013-01-01

Robot-assisted surgical procedures, taking advantage of the high soft tissue contrast and real-time imaging of magnetic resonance imaging (MRI), are developing rapidly. However, it is crucial to maintain tactile force feedback in MRI-guided needle-based procedures. This paper presents a Fabry-Perot interference (FPI) based system of an MRI-compatible fiber optic sensor which has been integrated into a piezoelectrically actuated robot for prostate cancer biopsy and brachytherapy in 3T MRI scan...

MO-B-BRC-01: Introduction [Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Prisciandaro, J. [University of Michigan (United States)

2016-06-15

Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.

WE-G-BRD-07: Automated MR Image Standardization and Auto-Contouring Strategy for MRI-Based Adaptive Brachytherapy for Cervix Cancer

International Nuclear Information System (INIS)

Saleh, H Al; Erickson, B; Paulson, E

2015-01-01

Purpose: MRI-based adaptive brachytherapy (ABT) is an emerging treatment modality for patients with gynecological tumors. However, MR image intensity non-uniformities (IINU) can vary from fraction to fraction, complicating image interpretation and auto-contouring accuracy. We demonstrate here an automated MR image standardization and auto-contouring strategy for MRI-based ABT of cervix cancer. Methods: MR image standardization consisted of: 1) IINU correction using the MNI N3 algorithm, 2) noise filtering using anisotropic diffusion, and 3) signal intensity normalization using the volumetric median. This post-processing chain was implemented as a series of custom Matlab and Java extensions in MIM (v6.4.5, MIM Software) and was applied to 3D T2 SPACE images of six patients undergoing MRI-based ABT at 3T. Coefficients of variation (CV=σ/µ) were calculated for both original and standardized images and compared using Mann-Whitney tests. Patient-specific cumulative MR atlases of bladder, rectum, and sigmoid contours were constructed throughout ABT, using original and standardized MR images from all previous ABT fractions. Auto-contouring was performed in MIM two ways: 1) best-match of one atlas image to the daily MR image, 2) multi-match of all previous fraction atlas images to the daily MR image. Dice’s Similarity Coefficients (DSCs) were calculated for auto-generated contours relative to reference contours for both original and standardized MR images and compared using Mann-Whitney tests. Results: Significant improvements in CV were detected following MR image standardization (p=0.0043), demonstrating an improvement in MR image uniformity. DSCs consistently increased for auto-contoured bladder, rectum, and sigmoid following MR image standardization, with the highest DSCs detected when the combination of MR image standardization and multi-match cumulative atlas-based auto-contouring was utilized. Conclusion: MR image standardization significantly improves MR image

WE-G-BRD-07: Automated MR Image Standardization and Auto-Contouring Strategy for MRI-Based Adaptive Brachytherapy for Cervix Cancer

Energy Technology Data Exchange (ETDEWEB)

Saleh, H Al; Erickson, B; Paulson, E [Medical College of Wisconsin, Milwaukee, WI (United States)

2015-06-15

Purpose: MRI-based adaptive brachytherapy (ABT) is an emerging treatment modality for patients with gynecological tumors. However, MR image intensity non-uniformities (IINU) can vary from fraction to fraction, complicating image interpretation and auto-contouring accuracy. We demonstrate here an automated MR image standardization and auto-contouring strategy for MRI-based ABT of cervix cancer. Methods: MR image standardization consisted of: 1) IINU correction using the MNI N3 algorithm, 2) noise filtering using anisotropic diffusion, and 3) signal intensity normalization using the volumetric median. This post-processing chain was implemented as a series of custom Matlab and Java extensions in MIM (v6.4.5, MIM Software) and was applied to 3D T2 SPACE images of six patients undergoing MRI-based ABT at 3T. Coefficients of variation (CV=σ/µ) were calculated for both original and standardized images and compared using Mann-Whitney tests. Patient-specific cumulative MR atlases of bladder, rectum, and sigmoid contours were constructed throughout ABT, using original and standardized MR images from all previous ABT fractions. Auto-contouring was performed in MIM two ways: 1) best-match of one atlas image to the daily MR image, 2) multi-match of all previous fraction atlas images to the daily MR image. Dice’s Similarity Coefficients (DSCs) were calculated for auto-generated contours relative to reference contours for both original and standardized MR images and compared using Mann-Whitney tests. Results: Significant improvements in CV were detected following MR image standardization (p=0.0043), demonstrating an improvement in MR image uniformity. DSCs consistently increased for auto-contoured bladder, rectum, and sigmoid following MR image standardization, with the highest DSCs detected when the combination of MR image standardization and multi-match cumulative atlas-based auto-contouring was utilized. Conclusion: MR image standardization significantly improves MR image

Development of a Pneumatic Robot for MRI-guided Transperineal Prostate Biopsy and Brachytherapy: New Approaches

OpenAIRE

Song, Sang-Eun; Cho, Nathan B.; Fischer, Gregory; Hata, Nobuhito; Tempany, Clare; Fichtinger, Gabor; Iordachita, Iulian

2010-01-01

Magnetic Resonance Imaging (MRI) guided prostate biopsy and brachytherapy has been introduced in order to enhance the cancer detection and treatment. For the accurate needle positioning, a number of robotic assistants have been developed. However, problems exist due to the strong magnetic field and limited workspace. Pneumatically actuated robots have shown the minimum distraction in the environment but the confined workspace limits optimal robot design and thus controllability is often poor....

SU-E-T-661: Quantitative MRI Assessment of a Novel Direction-Modulated Brachytherapy Tandem Applicator for Cervical Cancer

Energy Technology Data Exchange (ETDEWEB)

Soliman, A; Elzibak, A; Fatemi, A; Safigholi, H; Leung, E; Ravi, A; Song, W [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Han, D [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); University of California, San Diego, La Jolla, CA (United States)

2015-06-15

Purpose: To quantitatively evaluate the MR image quality of a novel direction modulated brachytherapy (DMBT) tandem applicator for cervical cancer, using the clinical MRI scanning protocol for image guided brachytherapy. Methods: The tungsten alloy-based applicator was placed in a water phantom and clinical imaging protocol was performed. Axial images were acquired using 2D turbo-spin echo (TSE) T2-weighted sequence on a 1.5T GE 450w MR scanner and an 8-channel body coil. As multi-channel receiver coil was used, inhomogeneities in the B1 receive field must be considered before performing the quantification process. Therefore the applicator was removed from the phantom and the whole imaging session was performed again for the water phantom with the same parameters. Images from the two scans were then subtracted, resulting in a difference image that only shows the applicator with its surrounding magnetic susceptibility dipole artifact. Line profiles were drawn and plotted on the difference image at various angles and locations along the tandem. Full width at half maximum (FWHM) was measured at all the line profiles to quantify the extent of the artifact. Additionally, the extent of the artifact along the diameter of the tandem was measured at various angles and locations. Results: After removing the background inhomogeneities of the receiver coil, FWHM of the tandem measured 5.75 ± 0.35 mm (the physical tandem diameter is 5.4 mm). The average extent of the artifacts along the diameter of the tandem measured is 2.14 ± 0.56 mm. In contrast to CT imaging of the same applicator (not shown here), the tandem can be easily identified without additional correction algorithms. Conclusion: This work demonstrated that the novel DMBT tandem applicator has minimal susceptibility artifact in T2-weighted images employed in clinical practice for MRI-guided brachytherapy of cervical cancer.

MRI dosimetry using an echo-quotient technique for high dose rate brachytherapy

International Nuclear Information System (INIS)

Ansbacher, W.

1996-01-01

MRI gel dosimetry is a relatively new technique that has many advantages over conventional methods, and is particularly suited to High Dose Rate (HDR) Brachytherapy. The dosimeter has high spatial resolution and a water-equivalent response over a wide range of photon energies. Because it is an integrating dosimeter, it allows for efficient mapping of the dynamically-produced distributions from an HDR source. As an example of this technique, the dose response, which is calibrated in terms of the change in spin-spin relaxation time, has been used to investigate the anisotropy of an HDR source. (author). 1 fig

Multicentre treatment planning study of MRI-guided brachytherapy for cervical cancer: Comparison between tandem-ovoid applicator users

International Nuclear Information System (INIS)

Nomden, Christel N.; Leeuw, Astrid A.C. de; Van Limbergen, Erik; Brabandere, Marisol de; Nulens, An; Nout, Remi A.; Laman, Mirjam; Ketelaars, Martijn; Lutgens, Ludovicus; Reniers, Brigitte; Jürgenliemk-Schulz, Ina Maria

2013-01-01

Background and purpose: To compare MRI-guided treatment planning approaches between four centres that use tandem-ovoid applicators. Material and methods: Four centres generated three treatment plans for four patients: standard, optimised intracavitary, and optimised intracavitary/interstitial. Prescribed D90 High-Risk CTV (HR-CTV) was 85 Gy EQD2 (external-beam radiotherapy and brachytherapy), while the D 2cc OAR limit was 90 Gy EQD2 for bladder and 75 Gy EQD2 for rectum, sigmoid, and bowel, respectively. DVH-parameters, source loading patterns and spatial dose distributions of the three treatment plans were compared. Results: The standard plans of the different centres were comparable with respect to the D90 HR-CTV, but differed in OAR doses. MRI-guided intracavitary optimisation resulted in organ sparing and smaller variation in DVH parameters between the centres. Adding interstitial needles led to target dose escalation while respecting the OAR constraints. However, substantial differences in relative weights of the applicator parts resulted in an increased variation in DVH parameters and locations of high dose regions. Conclusions: MRI-guided brachytherapy treatment planning optimisation provides the possibility to increase the dose to the HR-CTV and spare the OARs. Depending on the degree of conformity the centres make different choices in relative weighting of applicator parts, leading to different dose distributions

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

High-Field MRI-Compatible Needle Placement Robot for Prostate Interventions

Science.gov (United States)

SU, Hao; CAMILO, Alex; COLE, Gregory A.; HATA, Nobuhiko; TEMPANY, Clare M.; FISCHER, Gregory S.

2014-01-01

This paper presents the design of a magnetic resonance imaging (MRI) compatible needle placement system actuated by piezoelectric actuators for prostate brachytherapy and biopsy. An MRI-compatible modular 3 degree-of-freedom (DOF) needle driver module coupled with a 3-DOF x-y-z stage is proposed as a slave robot to precisely deliver radioactive brachytherapy seeds under interactive MRI guidance. The needle driver module provides for needle cannula rotation, needle insertion and cannula retraction to enable the brachytherapy procedure with the preloaded needles. The device mimics the manual physician gesture by two point grasping (hub and base) and provides direct force measurement of needle insertion force by fiber optic force sensors. The fabricated prototype is presented and an experiment with phantom trials in 3T MRI is analyzed to demonstrate the system compatibility. PMID:21335868

Sequential evaluation of prostate edema after permanent seed prostate brachytherapy using CT-MRI fusion

International Nuclear Information System (INIS)

Taussky, Daniel; Austen, Lyn; Toi, Ants; Yeung, Ivan; Williams, Theresa; Pearson, Shannon; McLean, Michael; Pond, Gregory; Crook, Juanita

2005-01-01

Purpose: To analyze the extent and time course of prostate edema and its effect on dosimetry after permanent seed prostate brachytherapy. Methods and Materials: Twenty patients scheduled for permanent seed 125 I prostate brachytherapy agreed to a prospective study on postimplant edema. Implants were preplanned using transrectal ultrasonography. Postimplant dosimetry was calculated using computed tomography-magnetic resonance imaging (CT-MRI) fusion on the day of the implant (Day 1) and Days 8 and 30. The prostate was contoured on MRI, and the seeds were located on CT. Factors investigated for an influence on edema were the number of seeds and needles, preimplant prostate volume, transitional zone index (transition zone volume divided by prostate volume), age, and prostate-specific antigen level. Prostate dosimetry was evaluated by the percentage of the prostate volume receiving 100% of the prescribed dose (V 100 ) and percentage of prescribed dose received by 90% of the prostate volume (D 90 ). Results: Prostate edema was maximal on Day 1, with the median prostate volume 31% greater than preimplant transrectal ultrasound volume (range, 0.93-1.72; p 100 on Day 1 was 93.6% (range, 86.0-98.2%) and was 96.3% (range, 85.7-99.5%) on Day 30 (p = 0.079). Patients with a Day 1 V 100 >93% were less affected by edema resolution, showing a median increase in V 100 of 0.67% on Day 30 compared with 2.77% for patients with a V 100 100 >93%)

Fiber Bragg gratings-based sensing for real-time needle tracking during MR-guided brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Borot de Battisti, Maxence, E-mail: M.E.P.Borot@umcutrecht.nl; Maenhout, Metha; Lagendijk, Jan J. W.; Vulpen, Marco van; Moerland, Marinus A. [Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, Utrecht 3584 CX (Netherlands); Denis de Senneville, Baudouin [Imaging Division, University Medical Center Utrecht, Heidelberglaan 100, Utrecht 3584 CX, The Netherlands and IMB, UMR 5251 CNRS/University of Bordeaux, Talence 33400 (France); Hautvast, Gilion; Binnekamp, Dirk [Philips Group Innovation Biomedical Systems, Eindhoven 5656 AE (Netherlands)

2016-10-15

Purpose: The development of MR-guided high dose rate (HDR) brachytherapy is under investigation due to the excellent tumor and organs at risk visualization of MRI. However, MR-based localization of needles (including catheters or tubes) has inherently a low update rate and the required image interpretation can be hampered by signal voids arising from blood vessels or calcifications limiting the precision of the needle guidance and reconstruction. In this paper, a new needle tracking prototype is investigated using fiber Bragg gratings (FBG)-based sensing: this prototype involves a MR-compatible stylet composed of three optic fibers with nine sets of embedded FBG sensors each. This stylet can be inserted into brachytherapy needles and allows a fast measurement of the needle deflection. This study aims to assess the potential of FBG-based sensing for real-time needle (including catheter or tube) tracking during MR-guided intervention. Methods: First, the MR compatibility of FBG-based sensing and its accuracy was evaluated. Different known needle deflections were measured using FBG-based sensing during simultaneous MR-imaging. Then, a needle tracking procedure using FBG-based sensing was proposed. This procedure involved a MR-based calibration of the FBG-based system performed prior to the interventional procedure. The needle tracking system was assessed in an experiment with a moving phantom during MR imaging. The FBG-based system was quantified by comparing the gold-standard shapes, the shape manually segmented on MRI and the FBG-based measurements. Results: The evaluation of the MR compatibility of FBG-based sensing and its accuracy shows that the needle deflection could be measured with an accuracy of 0.27 mm on average. Besides, the FBG-based measurements were comparable to the uncertainty of MR-based measurements estimated at half the voxel size in the MR image. Finally, the mean(standard deviation) Euclidean distance between MR- and FBG-based needle position

MRI assessment of cervical cancer for adaptive radiotherapy

International Nuclear Information System (INIS)

Dimopoulos, Johannes C.A.; Schirl, Gertrude; Baldinger, Anja; Poetter, Richard; Helbich, Thomas H.

2009-01-01

Purpose: To assess the importance of the information obtained from MRI for adaptive cervix cancer radiotherapy. Patients and methods: 49 patients with cervix cancer, treated by external-beam radiotherapy (EBRT) and MRI-assisted high-dose-rate brachytherapy ± concomitant cisplatin, underwent MRI at diagnosis and at the time of brachytherapy fractions. 190 MRI examinations were performed. Pretreatment scans were correlated with clinical examination (CE) findings. Measurements in 3-D of the tumor extension and also of the distance from the tumor to the pelvic side wall were performed using both MRI and CE. The tumor volume regression induced initially by EBRT and the subsequent regression after each brachytherapy fraction were assessed. Results: MRI and CE showed 92% agreement in overall parametrial staging and 73% agreement in terms of vaginal involvement. There was, however, disagreement in parametrial side (right/left) classification in 25% of the parametria examined. These were patients with unilateral displacement of the cervix and contralateral invasion of the parametrium. The mean tumor volume on the pretreatment MRI scan (GTVD) was 61 cm 3 . At the time of the four brachytherapy fractions the mean was 16 cm 3 , 10 cm 3 , 9 cm 3 , and 8 cm 3 , defined as the GTVBT plus the gray zones in the parametria. Conclusion: CE and MRI findings agree well in terms of overall staging. The clinical assessment of side-specific parametrial invasion improved when having access to the additional knowledge obtained from MRI. The greatest decrease in tumor volume occurs during EBRT, whereas tumor regression between the first and subsequent brachytherapy fractions is minor. (orig.)

Clinical Outcomes of Computed Tomography–Based Volumetric Brachytherapy Planning for Cervical Cancer

International Nuclear Information System (INIS)

Simpson, Daniel R.; Scanderbeg, Daniel J.; Carmona, Ruben; McMurtrie, Riley M.; Einck, John; Mell, Loren K.; McHale, Michael T.; Saenz, Cheryl C.; Plaxe, Steven C.; Harrison, Terry; Mundt, Arno J.; Yashar, Catheryn M.

2015-01-01

Purpose/Objectives: A report of clinical outcomes of a computed tomography (CT)-based image guided brachytherapy (IGBT) technique for treatment of cervical cancer. Methods and Materials: Seventy-six women with International Federation of Gynecology and Obstetrics stage IB to IVA cervical carcinoma diagnosed between 2007 and 2014 were treated with definitive external beam radiation therapy (EBRT) with or without concurrent chemotherapy followed by high-dose-rate (HDR) IGBT. All patients underwent planning CT simulation at each implantation. A high-risk clinical target volume (HRCTV) encompassing any visible tumor and the entire cervix was contoured on the simulation CT. When available, magnetic resonance imaging (MRI) was performed at implantation to assist with tumor delineation. The prescription dose was prescribed to the HRCTV. Results: The median follow-up time was 17 months. Thirteen patients (17%) had an MRI done before brachytherapy, and 16 patients (21%) were treated without MRI guidance. The mean EBRT/IGBT sum 2-Gy equivalent dose (EQD2) delivered to the 90% volume of the HRCTV was 86.3 Gy. The mean maximum EQD2s delivered to 2 cm 3 of the rectum, sigmoid, and bladder were 67.5 Gy, 66.2 Gy, and 75.3 Gy, respectively. The 2-year cumulative incidences of local, locoregional, and distant failure were 5.8% (95% confidence interval [CI]: 1.4%-14.8%), 15.1% (95% CI: 5.4%-29.4%), and 24.3% (95% CI: 12.1%-38.9%), respectively. The 2-year overall and disease-free survival rates were 75% (95% CI, 61%-91%) and 73% (95% CI, 60%-90%), respectively. Twenty-nine patients (38%) experienced grade ≥2 acute toxicity, with 5 cases of acute grade 3 toxicity and no grade ≥4 toxicities. One patient experienced grade 3 gastrointestinal toxicity. No other late grade ≥3 events were observed. Conclusions: This is the largest report to date of CT/MRI-based IGBT for the treatment of cervical cancer. The results are promising, with excellent local control and acceptable

Clinical Outcomes of Computed Tomography–Based Volumetric Brachytherapy Planning for Cervical Cancer

Energy Technology Data Exchange (ETDEWEB)

Simpson, Daniel R., E-mail: drsimpson@ucsd.edu [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Scanderbeg, Daniel J.; Carmona, Ruben; McMurtrie, Riley M.; Einck, John; Mell, Loren K. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); McHale, Michael T.; Saenz, Cheryl C.; Plaxe, Steven C.; Harrison, Terry [Department of Gynecologic Oncology, University of California San Diego, La Jolla, California (United States); Mundt, Arno J.; Yashar, Catheryn M. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States)

2015-09-01

Purpose/Objectives: A report of clinical outcomes of a computed tomography (CT)-based image guided brachytherapy (IGBT) technique for treatment of cervical cancer. Methods and Materials: Seventy-six women with International Federation of Gynecology and Obstetrics stage IB to IVA cervical carcinoma diagnosed between 2007 and 2014 were treated with definitive external beam radiation therapy (EBRT) with or without concurrent chemotherapy followed by high-dose-rate (HDR) IGBT. All patients underwent planning CT simulation at each implantation. A high-risk clinical target volume (HRCTV) encompassing any visible tumor and the entire cervix was contoured on the simulation CT. When available, magnetic resonance imaging (MRI) was performed at implantation to assist with tumor delineation. The prescription dose was prescribed to the HRCTV. Results: The median follow-up time was 17 months. Thirteen patients (17%) had an MRI done before brachytherapy, and 16 patients (21%) were treated without MRI guidance. The mean EBRT/IGBT sum 2-Gy equivalent dose (EQD2) delivered to the 90% volume of the HRCTV was 86.3 Gy. The mean maximum EQD2s delivered to 2 cm{sup 3} of the rectum, sigmoid, and bladder were 67.5 Gy, 66.2 Gy, and 75.3 Gy, respectively. The 2-year cumulative incidences of local, locoregional, and distant failure were 5.8% (95% confidence interval [CI]: 1.4%-14.8%), 15.1% (95% CI: 5.4%-29.4%), and 24.3% (95% CI: 12.1%-38.9%), respectively. The 2-year overall and disease-free survival rates were 75% (95% CI, 61%-91%) and 73% (95% CI, 60%-90%), respectively. Twenty-nine patients (38%) experienced grade ≥2 acute toxicity, with 5 cases of acute grade 3 toxicity and no grade ≥4 toxicities. One patient experienced grade 3 gastrointestinal toxicity. No other late grade ≥3 events were observed. Conclusions: This is the largest report to date of CT/MRI-based IGBT for the treatment of cervical cancer. The results are promising, with excellent local control and acceptable

Proficiency-based cervical cancer brachytherapy training.

Science.gov (United States)

Zhao, Sherry; Francis, Louise; Todor, Dorin; Fields, Emma C

2018-04-25

Although brachytherapy increases the local control rate for cervical cancer, there has been a progressive decline in its use. Furthermore, the training among residency programs for gynecologic brachytherapy varies considerably, with some residents receiving little to no training. This trend is especially concerning given the association between poor applicator placement and decline in local control. Considering the success of proficiency-based training in other procedural specialties, we developed and implemented a proficiency-based cervical brachytherapy training curriculum for our residents. Each resident placed tandem and ovoid applicators with attending guidance and again alone 2 weeks later using a pelvic model that was modified to allow for cervical brachytherapy. Plain films were taken of the pelvic model, and applicator placement quality was evaluated. Other evaluated metrics included retention of key procedural details, the time taken for each procedure and presession and postsession surveys to assess confidence. During the initial session, residents on average met 4.5 of 5 placement criteria, which improved to 5 the second session. On average, residents were able to remember 7.6 of the 8 key procedural steps. Execution time decreased by an average of 10.5%. Resident confidence with the procedure improved dramatically, from 2.6 to 4.6 of 5. Residents who had previously never performed a tandem and ovoid procedure showed greater improvements in these criteria than those who had. All residents strongly agreed that the training was helpful and wanted to participate again the following year. Residents participating in this simulation training had measurable improvements in the time to perform the procedure, applicator placement quality, and confidence. This curriculum is easy to implement and is of great value for training residents, and would be particularly beneficial in programs with low volume of cervical brachytherapy cases. Simulation programs could

SU-E-T-366: Clinical Implementation of MR-Guided Vaginal Cylinder Brachytherapy

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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.

SU-E-T-366: Clinical Implementation of MR-Guided Vaginal Cylinder Brachytherapy

International Nuclear Information System (INIS)

Owrangi, A; Jolly, S; Balter, J; Cao, Y; Young, L; Zhu, T; Prisciandaro, J

2014-01-01

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

Patient-based dosimetric comparison of interstitial and intracavitary brachytherapy in cases of cancer cervix

International Nuclear Information System (INIS)

Bansal, Anil K.; Julka, P.K.; Sharma, D.N.; Rustogi, Ashish; Subramani, V.; Prabhakar, R.; Rath, G.K.; Semwal, Manoj K.; Thulkar, S.

2008-01-01

Brachytherapy in the form of High Dose Rate (HDR) intracavitary radiotherapy (ICRT) along with external beam radiotherapy(EBRT) is the main treatment in cancer cervix. Of late, some large centres have started practicing template based transperineal interstitial brachytherapy (TIB) for advanced/ bulky cancer cervix. Usually, TIB is given for patients with advanced disease/ distorted anatomy or recurrent disease for better lateral target coverage. CT/MRI/USG based planning has made volumetric dosimetry possible for the target and the organs at risk (OARs). This has resulted in better correlation between dose received and treatment outcome in terms of tumour control and late toxicities as against the point dosimetry system. It has been shown by many studies that ICRU based point dose reporting may not represent the actual doses received by the OARs. Though it is expected that TIB gives better target coverage and OAR sparing in advanced/ bulky cancer cervix cases as compared to ICRT, detailed patient studies on the subject have not been reported. We have carried out dosimetric comparison between ICRT and TIB for cancer cervix patients undergoing treatment at our centre in terms of treated volume and doses to OARs

Deformable registration of x-ray to MRI for post-implant dosimetry in prostate brachytherapy

Science.gov (United States)

Park, Seyoun; Song, Danny Y.; Lee, Junghoon

2016-03-01

Post-implant dosimetric assessment in prostate brachytherapy is typically performed using CT as the standard imaging modality. However, poor soft tissue contrast in CT causes significant variability in target contouring, resulting in incorrect dose calculations for organs of interest. CT-MR fusion-based approach has been advocated taking advantage of the complementary capabilities of CT (seed identification) and MRI (soft tissue visibility), and has proved to provide more accurate dosimetry calculations. However, seed segmentation in CT requires manual review, and the accuracy is limited by the reconstructed voxel resolution. In addition, CT deposits considerable amount of radiation to the patient. In this paper, we propose an X-ray and MRI based post-implant dosimetry approach. Implanted seeds are localized using three X-ray images by solving a combinatorial optimization problem, and the identified seeds are registered to MR images by an intensity-based points-to-volume registration. We pre-process the MR images using geometric and Gaussian filtering. To accommodate potential soft tissue deformation, our registration is performed in two steps, an initial affine transformation and local deformable registration. An evolutionary optimizer in conjunction with a points-to-volume similarity metric is used for the affine registration. Local prostate deformation and seed migration are then adjusted by the deformable registration step with external and internal force constraints. We tested our algorithm on six patient data sets, achieving registration error of (1.2+/-0.8) mm in < 30 sec. Our proposed approach has the potential to be a fast and cost-effective solution for post-implant dosimetry with equivalent accuracy as the CT-MR fusion-based approach.

Interactive, multi-modality image registrations for combined MRI/MRSI-planned HDR prostate brachytherapy

Directory of Open Access Journals (Sweden)

Galen Reed

2011-03-01

Full Text Available Purpose: This study presents the steps and criteria involved in the series of image registrations used clinically during the planning and dose delivery of focal high dose-rate (HDR brachytherapy of the prostate. Material and methods: Three imaging modalities – Magnetic Resonance Imaging (MRI, Magnetic Resonance Spectroscopic Imaging (MRSI, and Computed Tomography (CT – were used at different steps during the process. MRSI is used for identification of dominant intraprosatic lesions (DIL. A series of rigid and nonrigid transformations were applied to the data to correct for endorectal-coil-induced deformations and for alignment with the planning CT. Mutual information was calculated as a morphing metric. An inverse planning optimization algorithm was applied to boost dose to the DIL while providing protection to the urethra, penile bulb, rectum, and bladder. Six prostate cancer patients were treated using this protocol. Results: The morphing algorithm successfully modeled the probe-induced prostatic distortion. Mutual information calculated between the morphed images and images acquired without the endorectal probe showed a significant (p = 0.0071 increase to that calculated between the unmorphed images and images acquired without the endorectal probe. Both mutual information and visual inspection serve as effective diagnostics of image morphing. The entire procedure adds less than thirty minutes to the treatment planning. Conclusion: This work demonstrates the utility of image transformations and registrations to HDR brachytherapy of prostate cancer.

Evaluation of an active magnetic resonance tracking system for interstitial brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Wang, Wei, E-mail: wwang21@partners.org [Department of Radiology, Brigham and Women’s Hospital, Boston, Massachusetts 02115 and Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women’s Hospital, Boston, Massachusetts 02115 (United States); Viswanathan, Akila N.; Damato, Antonio L.; Cormack, Robert A. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women’s Hospital, Boston, Massachusetts 02115 (United States); Chen, Yue; Tse, Zion [Department of Engineering, The University of Georgia, Athens, Georgia 30602 (United States); Pan, Li [Siemens Healthcare USA, Baltimore, Maryland 21287 (United States); Tokuda, Junichi; Schmidt, Ehud J. [Department of Radiology, Brigham and Women’s Hospital, Boston, Massachusetts 02115 (United States); Seethamraju, Ravi T. [Siemens Healthcare USA, Boston, Massachusetts 02115 (United States); Dumoulin, Charles L. [Radiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio 45229 (United States)

2015-12-15

-resolution 3D MRI of the phantom was performed followed by catheter digitization based on the catheter’s imaging artifacts. The catheter trajectory error was characterized in terms of the mean distance between corresponding dwell points in MRTR-generated catheter trajectory and MRI-based catheter digitization. The MRTR-based catheter trajectory reconstruction process was also performed on three gynecologic cancer patients, and then compared with catheter digitization based on MRI and CT. Results: The catheter tip localization error increased as the MRTR stylet moved further off-center and as the stylet’s orientation deviated from the main magnetic field direction. Fifteen catheters’ trajectories were reconstructed by MRTR. Compared with MRI-based digitization, the mean 3D error of MRTR-generated trajectories was 1.5 ± 0.5 mm with an in-plane error of 0.7 ± 0.2 mm and a tip error of 1.7 ± 0.5 mm. MRTR resolved ambiguity in catheter assignment due to crossed catheter paths, which is a common problem in image-based catheter digitization. In the patient studies, the MRTR-generated catheter trajectory was consistent with digitization based on both MRI and CT. Conclusions: The MRTR system provides accurate catheter tip localization and trajectory reconstruction in the MR environment. Relative to the image-based methods, it improves the speed, safety, and reliability of the catheter trajectory reconstruction in interstitial brachytherapy. MRTR may enable in-procedural dosimetric evaluation of implant target coverage.

Evaluation of an active magnetic resonance tracking system for interstitial brachytherapy

International Nuclear Information System (INIS)

Wang, Wei; Viswanathan, Akila N.; Damato, Antonio L.; Cormack, Robert A.; Chen, Yue; Tse, Zion; Pan, Li; Tokuda, Junichi; Schmidt, Ehud J.; Seethamraju, Ravi T.; Dumoulin, Charles L.

2015-01-01

-resolution 3D MRI of the phantom was performed followed by catheter digitization based on the catheter’s imaging artifacts. The catheter trajectory error was characterized in terms of the mean distance between corresponding dwell points in MRTR-generated catheter trajectory and MRI-based catheter digitization. The MRTR-based catheter trajectory reconstruction process was also performed on three gynecologic cancer patients, and then compared with catheter digitization based on MRI and CT. Results: The catheter tip localization error increased as the MRTR stylet moved further off-center and as the stylet’s orientation deviated from the main magnetic field direction. Fifteen catheters’ trajectories were reconstructed by MRTR. Compared with MRI-based digitization, the mean 3D error of MRTR-generated trajectories was 1.5 ± 0.5 mm with an in-plane error of 0.7 ± 0.2 mm and a tip error of 1.7 ± 0.5 mm. MRTR resolved ambiguity in catheter assignment due to crossed catheter paths, which is a common problem in image-based catheter digitization. In the patient studies, the MRTR-generated catheter trajectory was consistent with digitization based on both MRI and CT. Conclusions: The MRTR system provides accurate catheter tip localization and trajectory reconstruction in the MR environment. Relative to the image-based methods, it improves the speed, safety, and reliability of the catheter trajectory reconstruction in interstitial brachytherapy. MRTR may enable in-procedural dosimetric evaluation of implant target coverage

TU-AB-201-11: A Novel Theoretical Framework for MRI-Only Image Guided LDR Prostate and Breast Brachytherapy Implant Dosimetry

Energy Technology Data Exchange (ETDEWEB)

Soliman, A; Elzibak, A; Fatemi, A; Safigholi, H; Ravi, A; Morton, G; Song, W [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Han, D [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); University of California, San Diego, La Jolla, CA (United States)

2015-06-15

Purpose: To propose a novel framework for accurate model-based dose calculations using only MR images for LDR prostate and breast seed implant brachytherapy. Methods: Model-based dose calculation methodologies recommended by TG-186 require further knowledge about specific tissue composition, which is challenging with MRI. However, relying on MRI-only for implant dosimetry would reduce the soft tissue delineation uncertainty, costs, and uncertainties associated with multi-modality registration and fusion processes. We propose a novel framework to address this problem using quantitative MRI acquisitions and reconstruction techniques. The framework includes three steps: (1) Identify the locations of seeds(2) Identify the presence (or absence) of calcification(s)(3) Quantify the water and fat content in the underlying tissueSteps (1) and (2) consider the sources that limit patient dosimetry, particularly the inter-seed attenuation and the calcified regions; while step (3) targets the quantification of the tissue composition to consider the heterogeneities in the medium. Our preliminary work has shown that the seeds and the calcifications can be identified with MRI using both the magnitude and the phase images. By employing susceptibility-weighted imaging with specific post-processing techniques, the phase images can be further explored to distinguish the seeds from the calcifications. Absolute quantification of tissue, water, and fat content is feasible and was previously demonstrated in phantoms and in-vivo applications, particularly for brain diseases. The approach relies on the proportionality of the MR signal to the number of protons in an image volume. By employing appropriate correction algorithms for T1 - and T2*-related biases, B1 transmit and receive field inhomogeneities, absolute water/fat content can be determined. Results: By considering calcification and interseed attenuation, and through the knowledge of water and fat mass density, accurate patient

Three-dimensional brachytherapy optimization techniques in the treatment of patients with cervix cancer

International Nuclear Information System (INIS)

Haie-Meder, C.; Mazeron, R.; Verezesan, O.; Monnier, L.; Vieillot, S.; Dumas, I.; Lhomme, C.; Morice, P.; Barillot, I.

2009-01-01

Traditionally, prescription and treatment planning in intracavitary brachytherapy for cervix cancer have used either reference points (mainly points A and B) or reference isodoses (60 Gy according to ICRU recommendations) to report doses to the target volume. Doses to critical organs were reported at bladder and rectum ICRU points. This practice has been supported by a long-standing clinical experience that has yielded an acceptable therapeutic ratio. The recent development of imaging has contributed to the improvement in target and organs at risk knowledge. In 2005 and 2006, the European group of brachytherapy -European Society for therapeutic radiology and oncology (GEC-E.S.T.R.O.) recommendations publications on 3-D based image brachytherapy have defined the different volumes of interest. These recommendations have been validated with intercomparison delineation studies. With the concomitant development of remote after-loading projectors, provided with miniaturized sources, it is now possible to plan radiation doses by adjusting dwell positions and relative dwell time values. These procedures allow better coverage of the targets while sparing O.A.R.. The recent literature data evidence a significant improvement in local control with no increase in complications. Further studies are needed to better define the dose recommended in both tumour and organs at risk. This is one of the goals of the European study on MRI-guided brachytherapy in locally advanced cervical cancer (E.M.B.R.A.C.E.) protocol (meaning of acronym: an international study on MRI-guided brachytherapy in locally advanced cervical cancer). (authors)

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.

3D dosimetry in HDR brachytherapy resonance imaging nuclear magnetic (b= 0.2 t) using a base acrylic gel (MAGIC)

International Nuclear Information System (INIS)

Batista Hernandez, Guillermo; Velez, Graciela R.; Schurrer, Clemar

2009-01-01

Dosimetry gels using magnetic resonance imaging (MRI) has been extended in recent literature. Our study presents the preparation, calibration IRM of acrylic gel (MAGIC) and its application in measuring dose in a 3D distribution HDR Brachytherapy with 192Ir source. The first gels used were the type Fricke gels based on the relationship of dose and time T1 relaxation. In 2001, Fong presented a new normoxic gel known as MAGIC whose main components are Methacrylic Acid (polymerizing), and Hydroquinone (inhibitor of self-curing) based on the relationship of dose and T2 relaxation time. Subsequent studies make changes in the concentrations component of the MAGIC (Methacrylic Acid and Hydroquinone in particular) to observe the behavior of the sensitivity of the gel with respect to its components and beam magnetic resonance equipment using magnetic fields higher to 0.5 T. This is done with equipment available to the staff of a Radiotherapy clinic setting. MAGIC gel is prepared according to composition by Crescenti (6% methacrylic acid), is calibrated with a 60Co unit TERADI INVAP 8002c (Argentina). Was raised shooting in a Siemens MRI scanner of 0.2 T Magnetom Concerto irradiated with a team of Brachytherapy High Dose Rate (HDR) Micro selectron Nucletron's V2 HDR for comparison with dose distributions provided by the planning system from Nucletron PLATO Sunrise. Was obtained a calibration curve for doses ranging from 0 to 8.0 Gy and a field strength 0.2 T magnetic We compared the sensitivity obtained in our calibration (Slope of the calibration curve) with those presented in the literature. Two phantoms were prepared for measurement in brachytherapy: a PMMA and a PVC. It was noted that MAGIC gel reacts chemically with PMMA and cured prior to irradiation. The phantom of PVC (no reactions) were irradiated with Micro selectron equipment and measured the dose distribution in 3D MRI. Were measured doses at the points specified by the Planning System and PLATO Sunrise compared

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

A Dose-Volume Analysis of Magnetic Resonance Imaging-Aided High-Dose-Rate Image-Based Interstitial Brachytherapy for Uterine Cervical Cancer

International Nuclear Information System (INIS)

Yoshida, Ken; Yamazaki, Hideya; Takenaka, Tadashi; Kotsuma, Tadayuki; Yoshida, Mineo; Furuya, Seiichi; Tanaka, Eiichi; Uegaki, Tadaaki; Kuriyama, Keiko; Matsumoto, Hisanobu; Yamada, Shigetoshi; Ban, Chiaki

2010-01-01

Purpose: To investigate the feasibility of our novel image-based high-dose-rate interstitial brachytherapy (HDR-ISBT) for uterine cervical cancer, we evaluated the dose-volume histogram (DVH) according to the recommendations of the Gynecological GEC-ESTRO Working Group for image-based intracavitary brachytherapy (ICBT). Methods and Materials: Between June 2005 and June 2007, 18 previously untreated cervical cancer patients were enrolled. We implanted magnetic resonance imaging (MRI)-available plastic applicators by our unique ambulatory technique. Total treatment doses were 30-36 Gy (6 Gy per fraction) combined with external beam radiotherapy (EBRT). Treatment plans were created based on planning computed tomography with MRI as a reference. DVHs of the high-risk clinical target volume (HR CTV), intermediate-risk CTV (IR CTV), and the bladder and rectum were calculated. Dose values were biologically normalized to equivalent doses in 2-Gy fractions (EQD 2 ). Results: The median D90 (HR CTV) and D90 (IR CTV) per fraction were 6.8 Gy (range, 5.5-7.5) and 5.4 Gy (range, 4.2-6.3), respectively. The median V100 (HR CTV) and V100 (IR CTV) were 98.4% (range, 83-100) and 81.8% (range, 64-93.8), respectively. When the dose of EBRT was added, the median D90 and D100 of HR CTV were 80.6 Gy (range, 65.5-96.6) and 62.4 Gy (range, 49-83.2). The D 2cc of the bladder was 62 Gy (range, 51.4-89) and of the rectum was 65.9 Gy (range, 48.9-76). Conclusions: Although the targets were advanced and difficult to treat effectively by ICBT, MRI-aided image-based ISBT showed favorable results for CTV and organs at risk compared with previously reported image-based ICBT results.

A dose-volume analysis of magnetic resonance imaging-aided high-dose-rate image-based interstitial brachytherapy for uterine cervical cancer.

Science.gov (United States)

Yoshida, Ken; Yamazaki, Hideya; Takenaka, Tadashi; Kotsuma, Tadayuki; Yoshida, Mineo; Furuya, Seiichi; Tanaka, Eiichi; Uegaki, Tadaaki; Kuriyama, Keiko; Matsumoto, Hisanobu; Yamada, Shigetoshi; Ban, Chiaki

2010-07-01

To investigate the feasibility of our novel image-based high-dose-rate interstitial brachytherapy (HDR-ISBT) for uterine cervical cancer, we evaluated the dose-volume histogram (DVH) according to the recommendations of the Gynecological GEC-ESTRO Working Group for image-based intracavitary brachytherapy (ICBT). Between June 2005 and June 2007, 18 previously untreated cervical cancer patients were enrolled. We implanted magnetic resonance imaging (MRI)-available plastic applicators by our unique ambulatory technique. Total treatment doses were 30-36 Gy (6 Gy per fraction) combined with external beam radiotherapy (EBRT). Treatment plans were created based on planning computed tomography with MRI as a reference. DVHs of the high-risk clinical target volume (HR CTV), intermediate-risk CTV (IR CTV), and the bladder and rectum were calculated. Dose values were biologically normalized to equivalent doses in 2-Gy fractions (EQD(2)). The median D90 (HR CTV) and D90 (IR CTV) per fraction were 6.8 Gy (range, 5.5-7.5) and 5.4 Gy (range, 4.2-6.3), respectively. The median V100 (HR CTV) and V100 (IR CTV) were 98.4% (range, 83-100) and 81.8% (range, 64-93.8), respectively. When the dose of EBRT was added, the median D90 and D100 of HR CTV were 80.6 Gy (range, 65.5-96.6) and 62.4 Gy (range, 49-83.2). The D(2cc) of the bladder was 62 Gy (range, 51.4-89) and of the rectum was 65.9 Gy (range, 48.9-76). Although the targets were advanced and difficult to treat effectively by ICBT, MRI-aided image-based ISBT showed favorable results for CTV and organs at risk compared with previously reported image-based ICBT results. (c) 2010 Elsevier Inc. All rights reserved.

High-Field MRI-Compatible Needle Placement Robot for Prostate Interventions

OpenAIRE

SU, Hao; CAMILO, Alex; COLE, Gregory A.; HATA, Nobuhiko; TEMPANY, Clare M.; FISCHER, Gregory S.

2011-01-01

This paper presents the design of a magnetic resonance imaging (MRI) compatible needle placement system actuated by piezoelectric actuators for prostate brachytherapy and biopsy. An MRI-compatible modular 3 degree-of-freedom (DOF) needle driver module coupled with a 3-DOF x-y-z stage is proposed as a slave robot to precisely deliver radioactive brachytherapy seeds under interactive MRI guidance. The needle driver module provides for needle cannula rotation, needle insertion and cannula retrac...

Systematic evaluation of MRI findings in different stages of treatment of cervical cancer: Potential of MRI on delineation of target, pathoanatomic structures, and organs at risk

International Nuclear Information System (INIS)

Dimopoulos, Johannes; Schard, Gerdi; Berger, Daniel; Lang, Stefan; Goldner, Gregor; Helbich, Thomas; Poetter, Richard

2006-01-01

Purpose: To compare magnetic resonance imaging (MRI) findings at different stages of cervix cancer treatment and to define the potential of MRI to delineate the gross tumor volume (GTV), clinical target volume (CTV), pathoanatomic structures, and organs at risk (OAR) in brachytherapy. Methods and Materials: Forty-nine patients underwent MRI at diagnosis and at brachytherapy. The ability to discriminate anatomic structures on MRI was assessed (quality factor: 0 = inability to discriminate; 1 = fair discrimination; 2 = good discrimination; 3 = excellent discrimination). The overall ability to visualize (percentage of patients with quality factors greater than 0) and the overall discrimination quality score (mean quality factors of all patients) were estimated for the applicator, GTV at diagnosis (GTV D ), GTV at brachytherapy (GTV BT )/'gray zones,' cervix rim/uterine corpus, OAR, vaginal wall, and parametria. Results: The overall ability to visualize the applicator on MRI at brachytherapy was 100%; for the GTV BT /'gray zones,' cervix rim/uterine corpus, OAR, and vaginal wall, visualization was 98% (overall discrimination quality factors: 1.2, 2.9, 2.1, 1.9, 1.7, and 2.6). Three of 4 borders of parametrial space were defined in more than 98% (discrimination quality factors: 2.9, 2.1, and 1.2). Conclusion: Magnetic resonance imaging provides appropriate information for definition of the applicator, GTV, CTV, pathoanatomic structures, and OAR that enables precise delineation for cervix cancer brachytherapy

A Fabry-Perot Interferometry Based MRI-Compatible Miniature Uniaxial Force Sensor for Percutaneous Needle Placement

Science.gov (United States)

Shang, Weijian; Su, Hao; Li, Gang; Furlong, Cosme; Fischer, Gregory S.

2014-01-01

Robot-assisted surgical procedures, taking advantage of the high soft tissue contrast and real-time imaging of magnetic resonance imaging (MRI), are developing rapidly. However, it is crucial to maintain tactile force feedback in MRI-guided needle-based procedures. This paper presents a Fabry-Perot interference (FPI) based system of an MRI-compatible fiber optic sensor which has been integrated into a piezoelectrically actuated robot for prostate cancer biopsy and brachytherapy in 3T MRI scanner. The opto-electronic sensing system design was minimized to fit inside an MRI-compatible robot controller enclosure. A flexure mechanism was designed that integrates the FPI sensor fiber for measuring needle insertion force, and finite element analysis was performed for optimizing the correct force-deformation relationship. The compact, low-cost FPI sensing system was integrated into the robot and calibration was conducted. The root mean square (RMS) error of the calibration among the range of 0–10 Newton was 0.318 Newton comparing to the theoretical model which has been proven sufficient for robot control and teleoperation. PMID:25126153

Evaluation of Artifacts and Distortions of Titanium Applicators on 3.0-Tesla MRI: Feasibility of Titanium Applicators in MRI-Guided Brachytherapy for Gynecological Cancer

International Nuclear Information System (INIS)

Kim, Yusung; Muruganandham, Manickam; Modrick, Joseph M.; Bayouth, John E.

2011-01-01

Purpose: The aim of this study was to characterize the levels of artifacts and distortions of titanium applicators on 3.0-Tesla magnetic resonance imaging (MRI). Methods and Materials: Fletcher-Suit-Delclos-style tandem and ovoids (T and O) and tandem and ring applicator (T and R) were examined. The quality assurance (QA) phantoms for each applicator were designed and filled with copper sulphate solution (1.5 g/l). The artifacts were quantified with the registration of corresponding computed tomography (CT) images. A favorable MR sequence was searched in terms of artifacts. Using the sequence, the artifacts were determined. The geometric distortions induced by the applicators were quantified through each registration of CT and MRI without applicators. The artifacts of T and O were also evaluated on in vivo MRI datasets of 5 patients. Results: T1-weighted MRI with 1-mm slice thickness was found as a favorable MR sequence. Applying the sequence, the artifacts at the tandem tip of T and O and T and R were determined as 1.5 ± 0.5 mm in a superior direction in phantom studies. In the ovoids of T and O, we found artifacts less than 1.5 ± 0.5 mm. The artifacts of a T and O tandem in vivo were found as less than 2.6 ± 1.3 mm on T1-weighted MRI, whereas less than 6.9 ± 3.4 mm on T2-weighted MRI. No more than 1.2 ± 0.6 mm (3.0 ± 1.5 mm) of distortions, due to a titanium applicator, were measured on T1-weighted MRI (T2-). Conclusion: In 3.0-Tesla MRI, we found the artifact widths at the tip of tandem were less than 1.5 ± 0.5 mm for both T and O and T and R when using T1-weighted MRI in phantom studies. However, exclusive 3.0-Tesla MRI-guided brachytherapy planning with a titanium applicator should be cautiously implemented.

Accuracy of applicator tip reconstruction in MRI-guided interstitial 192Ir-high-dose-rate brachytherapy of liver tumors

International Nuclear Information System (INIS)

Wybranski, Christian; Eberhardt, Benjamin; Fischbach, Katharina; Fischbach, Frank; Walke, Mathias; Hass, Peter; Röhl, Friedrich-Wilhelm; Kosiek, Ortrud; Kaiser, Mandy; Pech, Maciej; Lüdemann, Lutz; Ricke, Jens

2015-01-01

Background and purpose: To evaluate the reconstruction accuracy of brachytherapy (BT) applicators tips in vitro and in vivo in MRI-guided 192 Ir-high-dose-rate (HDR)-BT of inoperable liver tumors. Materials and methods: Reconstruction accuracy of plastic BT applicators, visualized by nitinol inserts, was assessed in MRI phantom measurements and in MRI 192 Ir-HDR-BT treatment planning datasets of 45 patients employing CT co-registration and vector decomposition. Conspicuity, short-term dislocation, and reconstruction errors were assessed in the clinical data. The clinical effect of applicator reconstruction accuracy was determined in follow-up MRI data. Results: Applicator reconstruction accuracy was 1.6 ± 0.5 mm in the phantom measurements. In the clinical MRI datasets applicator conspicuity was rated good/optimal in ⩾72% of cases. 16/129 applicators showed not time dependent deviation in between MRI/CT acquisition (p > 0.1). Reconstruction accuracy was 5.5 ± 2.8 mm, and the average image co-registration error was 3.1 ± 0.9 mm. Vector decomposition revealed no preferred direction of reconstruction errors. In the follow-up data deviation of planned dose distribution and irradiation effect was 6.9 ± 3.3 mm matching the mean co-registration error (6.5 ± 2.5 mm; p > 0.1). Conclusion: Applicator reconstruction accuracy in vitro conforms to AAPM TG 56 standard. Nitinol-inserts are feasible for applicator visualization and yield good conspicuity in MRI treatment planning data. No preferred direction of reconstruction errors were found in vivo

Image based brachytherapy planning with special reference to gynaecological cancers

International Nuclear Information System (INIS)

Kirisits, C.

2008-01-01

Cervical cancer is the most common cancer among women in India and one of the most frequent malignancies in Europe and in North America. In addition endometrium, vagina and vulva cancer are treated with brachytherapy. Especially for locally advanced cervix cancer the integration of image based brachytherapy planning into clinical routine is becoming a new standard for the future

Dose-volume effect relationships for late rectal morbidity in patients treated with chemoradiation and MRI-guided adaptive brachytherapy for locally advanced cervical cancer: Results from the prospective multicenter EMBRACE study

DEFF Research Database (Denmark)

Mazeron, Renaud; Fokdal, Lars U; Kirchheiner, Kathrin

2016-01-01

Purpose To establish dose volume–effect relationships predicting late rectal morbidity in cervix cancer patients treated with concomitant chemoradiation and MRI-guided adaptive brachytherapy (IBABT) within the prospective EMBRACE study. Material and method All patients were treated with curative ...

GGEMS-Brachy: GPU GEant4-based Monte Carlo simulation for brachytherapy applications

Science.gov (United States)

Lemaréchal, Yannick; Bert, Julien; Falconnet, Claire; Després, Philippe; Valeri, Antoine; Schick, Ulrike; Pradier, Olivier; Garcia, Marie-Paule; Boussion, Nicolas; Visvikis, Dimitris

2015-07-01

In brachytherapy, plans are routinely calculated using the AAPM TG43 formalism which considers the patient as a simple water object. An accurate modeling of the physical processes considering patient heterogeneity using Monte Carlo simulation (MCS) methods is currently too time-consuming and computationally demanding to be routinely used. In this work we implemented and evaluated an accurate and fast MCS on Graphics Processing Units (GPU) for brachytherapy low dose rate (LDR) applications. A previously proposed Geant4 based MCS framework implemented on GPU (GGEMS) was extended to include a hybrid GPU navigator, allowing navigation within voxelized patient specific images and analytically modeled 125I seeds used in LDR brachytherapy. In addition, dose scoring based on track length estimator including uncertainty calculations was incorporated. The implemented GGEMS-brachy platform was validated using a comparison with Geant4 simulations and reference datasets. Finally, a comparative dosimetry study based on the current clinical standard (TG43) and the proposed platform was performed on twelve prostate cancer patients undergoing LDR brachytherapy. Considering patient 3D CT volumes of 400  × 250  × 65 voxels and an average of 58 implanted seeds, the mean patient dosimetry study run time for a 2% dose uncertainty was 9.35 s (≈500 ms 10-6 simulated particles) and 2.5 s when using one and four GPUs, respectively. The performance of the proposed GGEMS-brachy platform allows envisaging the use of Monte Carlo simulation based dosimetry studies in brachytherapy compatible with clinical practice. Although the proposed platform was evaluated for prostate cancer, it is equally applicable to other LDR brachytherapy clinical applications. Future extensions will allow its application in high dose rate brachytherapy applications.

GGEMS-Brachy: GPU GEant4-based Monte Carlo simulation for brachytherapy applications

International Nuclear Information System (INIS)

Lemaréchal, Yannick; Bert, Julien; Schick, Ulrike; Pradier, Olivier; Garcia, Marie-Paule; Boussion, Nicolas; Visvikis, Dimitris; Falconnet, Claire; Després, Philippe; Valeri, Antoine

2015-01-01

In brachytherapy, plans are routinely calculated using the AAPM TG43 formalism which considers the patient as a simple water object. An accurate modeling of the physical processes considering patient heterogeneity using Monte Carlo simulation (MCS) methods is currently too time-consuming and computationally demanding to be routinely used. In this work we implemented and evaluated an accurate and fast MCS on Graphics Processing Units (GPU) for brachytherapy low dose rate (LDR) applications. A previously proposed Geant4 based MCS framework implemented on GPU (GGEMS) was extended to include a hybrid GPU navigator, allowing navigation within voxelized patient specific images and analytically modeled 125 I seeds used in LDR brachytherapy. In addition, dose scoring based on track length estimator including uncertainty calculations was incorporated. The implemented GGEMS-brachy platform was validated using a comparison with Geant4 simulations and reference datasets. Finally, a comparative dosimetry study based on the current clinical standard (TG43) and the proposed platform was performed on twelve prostate cancer patients undergoing LDR brachytherapy. Considering patient 3D CT volumes of 400  × 250  × 65 voxels and an average of 58 implanted seeds, the mean patient dosimetry study run time for a 2% dose uncertainty was 9.35 s (≈500 ms 10 −6 simulated particles) and 2.5 s when using one and four GPUs, respectively. The performance of the proposed GGEMS-brachy platform allows envisaging the use of Monte Carlo simulation based dosimetry studies in brachytherapy compatible with clinical practice. Although the proposed platform was evaluated for prostate cancer, it is equally applicable to other LDR brachytherapy clinical applications. Future extensions will allow its application in high dose rate brachytherapy applications. (paper)

Clinical outcomes from an innovative protocol using serial ultrasound imaging and a single MR image to guide brachytherapy for locally advanced cervix cancer.

Science.gov (United States)

van Dyk, Sylvia; Narayan, Kailash; Bernshaw, David; Kondalsamy-Chennakesavan, Srinivas; Khaw, Pearly; Lin, Ming Yin; Schneider, Michal

The aim of this study was to report clinical outcomes in a series of patients who underwent serial ultrasound and a single MRI to plan and verify intracavitary brachytherapy. Data for patients who were referred for curative intent radiotherapy for International Federation of Gynecology and Obstetrics (FIGO) Stage 1-1V cervix cancer between January 2007 and March 2012 were analyzed. All patients received external beam radiotherapy with concurrent chemotherapy and sequential high-dose rate brachytherapy. Brachytherapy was planned and verified using serial ultrasound imaging and a single MRI. Data from 191 patients were available for analyses. The median (range) followup time was 5.08 (0.25-8.25) years. Five-year local control, failure-free survival, cancer-specific survival, and overall survival were 86%, 57.3%, 70% and 63%, respectively. Mean (standard deviation) combined external beam radiotherapy and brachytherapy target doses, equivalent to doses in 2 Gy fractions were 80.4 Gy10 (3.89), median (range) 80 (49-96) Gy10. Grade 3 or greater gastrointestinal, genitourinary, or vaginal late toxicity occurred in 3%, 1.6%, and 2% of patients, respectively. Survival, patterns of failure, and late complication rates were similar to published series of MRI/CT-based brachytherapy practices. This large study demonstrates that favorable treatment outcomes can be obtained using a pragmatic and innovative combination of ultrasound and MR imaging. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Implementation of three-dimensional planning in brachytherapy of high dose rate for gynecology therapies

International Nuclear Information System (INIS)

Sales, Camila Pessoa de

2015-01-01

This work aims to implement the three-dimensional (3D) planning for gynecological brachytherapy treatments. For this purpose, tests of acceptance and commissioning of brachytherapy equipment were performed to establish a quality and periodic assurance program. For this purpose, an important step was searching for a material to be used as a dummy source, since the applicators do not have any specific dummy. In addition, the validation of the use of applicators library was made for reconstruction in computed tomography (CT) and magnetic resonance imaging (MRI). In order to validate 3D planning, comparison of doses in dose assessment points used in bidimensional (2D) plans have been performed with volumetric doses to adjacent organs to the tumor. Finally, a protocol was established for 3D brachytherapy planning alternately using magnetic resonance image (MRI) and CT images, making evaluation of the dose in the tumor through the recording of MR and CT images. It was not possible to find a suitable material that could be used as dummy in MRI. However, the acquisition of the license's library for the applicators made possible the 3D planning based on MRI. No correlation was found between volumetric and specific doses analyzed, showing the importance of the implementation of 3D planning. The average ratio between D 2cc and ICRU Bladder dose was 1,74, 22% higher than the ratio found by others authors. For the rectum, D 2cc was less than dose point for 60% of fractions; the average difference was 12,5%. The average ratio between D 2cc and point dose rectum, 0,85, is equivalent to the value showed by Kim et al, 0,91. The D 2cc for sigmoid was 69% higher than point dose used, unless it was not possible compare this value, since the sigmoid point used in the 2D procedures is not used in others institutes. Relative dose in 2 cc of sigmoid was 57% of the prescription dose, the same value was found by in literature. This work enabled the implementation of a viable

Early observed transient prostate-specific antigen elevations on a pilot study of external beam radiation therapy and fractionated MRI guided High Dose Rate brachytherapy boost

International Nuclear Information System (INIS)

Singh, Anurag K; Godette, Denise J; Stall, Bronwyn R; Coleman, C Norman; Camphausen, Kevin; Ménard, Cynthia; Guion, Peter; Susil, Robert C; Citrin, Deborah E; Ning, Holly; Miller, Robert W; Ullman, Karen; Smith, Sharon; Crouse, Nancy Sears

2006-01-01

To report early observation of transient PSA elevations on this pilot study of external beam radiation therapy and magnetic resonance imaging (MRI) guided high dose rate (HDR) brachytherapy boost. Eleven patients with intermediate-risk and high-risk localized prostate cancer received MRI guided HDR brachytherapy (10.5 Gy each fraction) before and after a course of external beam radiotherapy (46 Gy). Two patients continued on hormones during follow-up and were censored for this analysis. Four patients discontinued hormone therapy after RT. Five patients did not receive hormones. PSA bounce is defined as a rise in PSA values with a subsequent fall below the nadir value or to below 20% of the maximum PSA level. Six previously published definitions of biochemical failure to distinguish true failure from were tested: definition 1, rise >0.2 ng/mL; definition 2, rise >0.4 ng/mL; definition 3, rise >35% of previous value; definition 4, ASTRO defined guidelines, definition 5 nadir + 2 ng/ml, and definition 6, nadir + 3 ng/ml. Median follow-up was 24 months (range 18–36 mo). During follow-up, the incidence of transient PSA elevation was: 55% for definition 1, 44% for definition 2, 55% for definition 3, 33% for definition 4, 11% for definition 5, and 11% for definition 6. We observed a substantial incidence of transient elevations in PSA following combined external beam radiation and HDR brachytherapy for prostate cancer. Such elevations seem to be self-limited and should not trigger initiation of salvage therapies. No definition of failure was completely predictive

T2*-weighted image/T2-weighted image fusion in postimplant dosimetry of prostate brachytherapy

International Nuclear Information System (INIS)

Katayama, Norihisa; Takemoto, Mitsuhiro; Yoshio, Kotaro

2011-01-01

Computed tomography (CT)/magnetic resonance imaging (MRI) fusion is considered to be the best method for postimplant dosimetry of permanent prostate brachytherapy; however, it is inconvenient and costly. In T2 * -weighted image (T2 * -WI), seeds can be easily detected without the use of an intravenous contrast material. We present a novel method for postimplant dosimetry using T2 * -WI/T2-weighted image (T2-WI) fusion. We compared the outcomes of T2 * -WI/T2-WI fusion-based and CT/T2-WI fusion-based postimplant dosimetry. Between April 2008 and July 2009, 50 consecutive prostate cancer patients underwent brachytherapy. All the patients were treated with 144 Gy of brachytherapy alone. Dose-volume histogram (DVH) parameters (prostate D90, prostate V100, prostate V150, urethral D10, and rectal D2cc) were prospectively compared between T2 * -WI/T2-WI fusion-based and CT/T2-WI fusion-based dosimetry. All the DVH parameters estimated by T2 * -WI/T2-WI fusion-based dosimetry strongly correlated to those estimated by CT/T2-WI fusion-based dosimetry (0.77≤ R ≤0.91). No significant difference was observed in these parameters between the two methods, except for prostate V150 (p=0.04). These results show that T2 * -WI/T2-WI fusion-based dosimetry is comparable or superior to MRI-based dosimetry as previously reported, because no intravenous contrast material is required. For some patients, rather large differences were observed in the value between the 2 methods. We thought these large differences were a result of seed miscounts in T2 * -WI and shifts in fusion. Improving the image quality of T2 * -WI and the image acquisition speed of T2 * -WI and T2-WI may decrease seed miscounts and fusion shifts. Therefore, in the future, T2 * -WI/T2-WI fusion may be more useful for postimplant dosimetry of prostate brachytherapy. (author)

Prostate CT segmentation method based on nonrigid registration in ultrasound-guided CT-based HDR prostate brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Yang, Xiaofeng, E-mail: xyang43@emory.edu; Rossi, Peter; Ogunleye, Tomi; Marcus, David M.; Jani, Ashesh B.; Curran, Walter J.; Liu, Tian [Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia 30322 (United States); Mao, Hui [Department of Radiology and Imaging Sciences, Emory University, Atlanta, Georgia 30322 (United States)

2014-11-01

Purpose: The technological advances in real-time ultrasound image guidance for high-dose-rate (HDR) prostate brachytherapy have placed this treatment modality at the forefront of innovation in cancer radiotherapy. Prostate HDR treatment often involves placing the HDR catheters (needles) into the prostate gland under the transrectal ultrasound (TRUS) guidance, then generating a radiation treatment plan based on CT prostate images, and subsequently delivering high dose of radiation through these catheters. The main challenge for this HDR procedure is to accurately segment the prostate volume in the CT images for the radiation treatment planning. In this study, the authors propose a novel approach that integrates the prostate volume from 3D TRUS images into the treatment planning CT images to provide an accurate prostate delineation for prostate HDR treatment. Methods: The authors’ approach requires acquisition of 3D TRUS prostate images in the operating room right after the HDR catheters are inserted, which takes 1–3 min. These TRUS images are used to create prostate contours. The HDR catheters are reconstructed from the intraoperative TRUS and postoperative CT images, and subsequently used as landmarks for the TRUS–CT image fusion. After TRUS–CT fusion, the TRUS-based prostate volume is deformed to the CT images for treatment planning. This method was first validated with a prostate-phantom study. In addition, a pilot study of ten patients undergoing HDR prostate brachytherapy was conducted to test its clinical feasibility. The accuracy of their approach was assessed through the locations of three implanted fiducial (gold) markers, as well as T2-weighted MR prostate images of patients. Results: For the phantom study, the target registration error (TRE) of gold-markers was 0.41 ± 0.11 mm. For the ten patients, the TRE of gold markers was 1.18 ± 0.26 mm; the prostate volume difference between the authors’ approach and the MRI-based volume was 7.28% ± 0

Prostate CT segmentation method based on nonrigid registration in ultrasound-guided CT-based HDR prostate brachytherapy

Science.gov (United States)

Yang, Xiaofeng; Rossi, Peter; Ogunleye, Tomi; Marcus, David M.; Jani, Ashesh B.; Mao, Hui; Curran, Walter J.; Liu, Tian

2014-01-01

Purpose: The technological advances in real-time ultrasound image guidance for high-dose-rate (HDR) prostate brachytherapy have placed this treatment modality at the forefront of innovation in cancer radiotherapy. Prostate HDR treatment often involves placing the HDR catheters (needles) into the prostate gland under the transrectal ultrasound (TRUS) guidance, then generating a radiation treatment plan based on CT prostate images, and subsequently delivering high dose of radiation through these catheters. The main challenge for this HDR procedure is to accurately segment the prostate volume in the CT images for the radiation treatment planning. In this study, the authors propose a novel approach that integrates the prostate volume from 3D TRUS images into the treatment planning CT images to provide an accurate prostate delineation for prostate HDR treatment. Methods: The authors’ approach requires acquisition of 3D TRUS prostate images in the operating room right after the HDR catheters are inserted, which takes 1–3 min. These TRUS images are used to create prostate contours. The HDR catheters are reconstructed from the intraoperative TRUS and postoperative CT images, and subsequently used as landmarks for the TRUS–CT image fusion. After TRUS–CT fusion, the TRUS-based prostate volume is deformed to the CT images for treatment planning. This method was first validated with a prostate-phantom study. In addition, a pilot study of ten patients undergoing HDR prostate brachytherapy was conducted to test its clinical feasibility. The accuracy of their approach was assessed through the locations of three implanted fiducial (gold) markers, as well as T2-weighted MR prostate images of patients. Results: For the phantom study, the target registration error (TRE) of gold-markers was 0.41 ± 0.11 mm. For the ten patients, the TRE of gold markers was 1.18 ± 0.26 mm; the prostate volume difference between the authors’ approach and the MRI-based volume was 7.28% ± 0

Cervical cancer. Application of MR imaging in brachytherapy

International Nuclear Information System (INIS)

Ebe, Kazuyu; Matsunaga, Naofumi

1996-01-01

For the purpose of application of MRI in arrangement of brachytherapy of cervical cancer, a method was proposed to see the radiation doses in surrounding tissues by superimposing the dose distribution pattern of the radiation source on the MR image. The applicator for the source was filled with water to get its T2-weighted image and was inserted in the patients. The MRI apparatus was Siemens Magnetom Vision (1.5T) with phased array coil. T2-weighted sagittal and coronary images were taken by turbospin echo and HASTE methods. The section thickness was 5 mm. The dose distribution pattern was superimposed on the frontal and lateral images by Siemens Mevaplan to see the doses in surrounding tissues. In 4 patients, it was possible to estimate the radiation dose in the posterior wall of bladder, anterior wall of rectum and urinary duct. The method is promising for arranging brachytherapy of cervical cancer. (K.H.)

Interstitial high-dose-rate brachytherapy in the treatment of base of tongue carcinoma

Energy Technology Data Exchange (ETDEWEB)

Takacsi-Nagy, Z.; Polgar, C.; Somogyi, A.; Major, T.; Fodor, J.; Nemeth, G. [Dept. of Radiotherapy, National Inst. of Oncology, Budapest (Hungary); Oberna, F. [Dept. of Maxillofacial Surgery, St. Rokus Hospital, Budapest (Hungary); Remenar, E.; Kasler, M. [Dept. of Head and Neck, Maxillofacial and Reconstructive Plastic Surgery, National Inst. of Oncology, Budapest (Hungary)

2004-12-01

Background and purpose: to date none of the studies examined the feasibility and efficacy of interstitial high-dose-rate (HDR) brachytherapy in the treatment of carcinoma of the tongue base. Therefore the aim of this study was to contribute to this issue. Patients and methods: between 1992 and 2000 37 patients (mean age 55 years) with T1-4 and NO-3 carcinoma of the base of tongue were presented. Neck dissection was carried out in twelve cases (32%). 30 patients with advanced stage received brachytherapy boost after 50-66.5 Gy (mean, 60 Gy) locoregional external beam irradiation (EBI) and 7 patients with early stage (T1-2, NO) were managed locally with wide tumor excision and sole brachytherapy. 4 of them underwent neck dissection and the others were subjected to 50 Gy regional EBI. The mean dose of boost and sole brachytherapy was 18 Gy and 28 Gy, respectively. Results: the median follow-up time for surviving patients was 51 months. The 7 sole brachytherapy patients are living with no evidence of disease. For patients treated with EBI and brachytherapy boost, the 5-year actuarial rate of local, locoregional recurrence-free and overall survival was 60%, 52% and 46%, respectively. For all patients in univariate analysis larger tumor size (T4 vs. T1-3) was significant negative predictor of local (RR: 7.23) and locoregional control (RR: 3.87), but nodal involvement was not. Delayed soft tissue ulceration and osteoradionecrosis occurred in 4 (13%) EBI and brachytherapy treated patients. None of the sole brachytherapy patients experienced severe late radiation toxicity. Conclusion: EBI combined with interstitial HDR brachytherapy boost result in acceptable local tumor control with low incidence of late side effects in patients with advanced disease. Fractionated sole HDR brachytherapy following tumor excision is a feasible treatment option for patients with early stage cancer and gives excellent local results. (orig.)

Pelvic MRI application to the dosimetric analysis in Brachytherapy of Uterine Cervix Carcinoma

International Nuclear Information System (INIS)

Ahn, S. J.; Chung, W. K.; Nah, B. K.

1997-01-01

Before we report the results of curative radiotherapy in cervix cancer patients, we review the significance and safety of our dose specification methods in the brachytherapy system to have the insight of the potential predictive value of doses at specific points. We analyze the 45 cases of cervix cancer patients treated with intracavitary brachytherapy. In the lateral simulation film we draw the isodose curve and observe the absorbed dose rate of point A, the reference point of bladder(SBD) and rectum(SRD). In the sagittal view of pelvic MRI film we demarcate the tumor volume(TV) and determine whether the prescription dose curve of point A covers the tumor volume adequately by drawing the isodose curve as correctly as possible. Also we estimate the maximum point dose of bladder (MBD) and rectum (MRD) and calculate the inclusion area where the absorbed dose rate is higher than that of point A in the bladder (HBV) and rectum (HRV), respectively. Of forty-five cases, the isodose curve of point A seems to cover tumor volume optimally in only 24 (53%). The optimal tumor coverage seems to be associated not with the stage of the disease but with the tumor volume. There is no statistically significant association between SBD/SRD and MBD/MRD, respectively. SRD has statistically significant association with HBV and HRV. Our current treatment calculation methods seem to have the defect in the aspects of the nonoptimal coverage of the bulky tumor and the inappropriate estimation of bladder dose. We therefore need to modify the applicator geometry to optimize the dose distribution at the position of lower tandem source. Also it appears that the position of the bladder in relation to the applicators needs to be defined individually to define 'hot spots'. (author)

Recommendations from Gynaecological (GYN) GEC-ESTRO Working Group (IV): Basic principles and parameters for MR imaging within the frame of image based adaptive cervix cancer brachytherapy

International Nuclear Information System (INIS)

Dimopoulos, Johannes C.A.; Petrow, Peter; Tanderup, Kari; Petric, Primoz; Berger, Daniel; Kirisits, Christian; Pedersen, Erik M.; Limbergen, Erik van; Haie-Meder, Christine; Pötter, Richard

2012-01-01

The GYN GEC-ESTRO working group issued three parts of recommendations and highlighted the pivotal role of MRI for the successful implementation of 3D image-based cervical cancer brachytherapy (BT). The main advantage of MRI as an imaging modality is its superior soft tissue depiction quality. To exploit the full potential of MRI for the better ability of the radiation oncologist to make the appropriate choice for the BT application technique and to accurately define the target volumes and the organs at risk, certain MR imaging criteria have to be fulfilled. Technical requirements, patient preparation, as well as image acquisition protocols have to be tailored to the needs of 3D image-based BT. The present recommendation is focused on the general principles of MR imaging for 3D image-based BT. Methods and parameters have been developed and progressively validated from clinical experience from different institutions (IGR, Universities of Vienna, Leuven, Aarhus and Ljubljana) and successfully applied during expert meetings, contouring workshops, as well as within clinical and interobserver studies. It is useful to perform pelvic MRI scanning prior to radiotherapy (“Pre-RT-MRI examination”) and at the time of BT (“BT MRI examination”) with one MR imager. Both low and high-field imagers, as well as both open and close magnet configurations conform to the requirements of 3D image-based cervical cancer BT. Multiplanar (transversal, sagittal, coronal and oblique image orientation) T2-weighted images obtained with pelvic surface coils are considered as the golden standard for visualisation of the tumour and the critical organs. The use of complementary MRI sequences (e.g. contrast-enhanced T1-weighted or 3D isotropic MRI sequences) is optional. Patient preparation has to be adapted to the needs of BT intervention and MR imaging. It is recommended to visualise and interpret the MR images on dedicated DICOM-viewer workstations, which should also assist the contouring

Adaptive brachytherapy of cervical cancer, comparison of conventional point A and CT based individual treatment planning

International Nuclear Information System (INIS)

Wanderaas, Anne D.; Langdal, Ingrid; Danielsen, Signe; Frykholm, Gunilla; Marthinsen, Anne B. L; Sundset, Marit

2012-01-01

Background. Locally advanced cervical cancer is commonly treated with external radiation therapy combined with local brachytherapy. The brachytherapy is traditionally given based on standard dose planning with prescription of dose to point A. Dosimetric aspects when changing from former standard treatment to individualized treatment plans based on computed tomography (CT) images are here investigated. Material and methods. Brachytherapy data from 19 patients with a total of 72 individual treatment fractions were retrospectively reviewed. Standard library plans were analyzed with respect to doses to organs at risk (OARs), and the result was compared to corresponding delivered individualized plans. The theoretical potential of further optimization based on prescription to target volumes was investigated. The treatments were performed with a Fletcher applicator. Results. For standard treatment planning, the tolerance dose limits were exceeded in the bladder, rectum and sigmoid in 26%, 4% and 15% of the plans, respectively. This was observed most often for the smallest target volumes. The individualized planning of the delivered treatment gave the possibility of controlling the dose to critical organs to below certain limits. The dose was still prescribed to point A. An increase in target dose coverage was achieved when additional individual optimization was performed, while still keeping the dose to the OARs below predefined limits. Relatively low average target coverage, especially for the largest volumes was however seen. Conclusion. The individualized delivered treatment plans ensured that doses to OARs were within acceptable limits. This was not the case in 42% of the corresponding standard plans. Further optimized treatment plans were found to give an overall better dose coverage. In lack of MR capacity, it may be favorable to use CT for planning due to possible protection of OARs. The CT based target volumes were, however, not equivalent to the volumes described

Pretreatment Endorectal Coil Magnetic Resonance Imaging Findings Predict Biochemical Tumor Control in Prostate Cancer Patients Treated With Combination Brachytherapy and External-Beam Radiotherapy

International Nuclear Information System (INIS)

Riaz, Nadeem; Afaq, Asim; Akin, Oguz; Pei Xin; Kollmeier, Marisa A.; Cox, Brett; Hricak, Hedvig; Zelefsky, Michael J.

2012-01-01

Purpose: To investigate the utility of endorectal coil magenetic resonance imaging (eMRI) in predicting biochemical relapse in prostate cancer patients treated with combination brachytherapy and external-beam radiotherapy. Methods and Materials: Between 2000 and 2008, 279 men with intermediate- or high-risk prostate cancer underwent eMRI of their prostate before receiving brachytherapy and supplemental intensity-modulated radiotherapy. Endorectal coil MRI was performed before treatment and retrospectively reviewed by two radiologists experienced in genitourinary MRI. Image-based variables, including tumor diameter, location, number of sextants involved, and the presence of extracapsular extension (ECE), were incorporated with other established clinical variables to predict biochemical control outcomes. The median follow-up was 49 months (range, 1–13 years). Results: The 5-year biochemical relapse-free survival for the cohort was 92%. Clinical findings predicting recurrence on univariate analysis included Gleason score (hazard ratio [HR] 3.6, p = 0.001), PSA (HR 1.04, p = 0.005), and National Comprehensive Cancer Network risk group (HR 4.1, p = 0.002). Clinical T stage and the use of androgen deprivation therapy were not correlated with biochemical failure. Imaging findings on univariate analysis associated with relapse included ECE on MRI (HR 3.79, p = 0.003), tumor size (HR 2.58, p = 0.04), and T stage (HR 1.71, p = 0.004). On multivariate analysis incorporating both clinical and imaging findings, only ECE on MRI and Gleason score were independent predictors of recurrence. Conclusions: Pretreatment eMRI findings predict for biochemical recurrence in intermediate- and high-risk prostate cancer patients treated with combination brachytherapy and external-beam radiotherapy. Gleason score and the presence of ECE on MRI were the only significant predictors of biochemical relapse in this group of patients.

Brachytherapy in cervix cancers: techniques and concepts evolution

International Nuclear Information System (INIS)

Haie-Meder, C.; Crevoisier, R. de; Petrow, P.; Fromm, S.; Delapierre, M.; Albano, M.; Petit, C.; Briot, E.

2003-01-01

Brachytherapy plays an important role in the treatment of patients with cervical carcinoma. Technical modalities have evolved during the last years and have benefited from imaging modalities development, specially MRI. Imaging modalities contribute to a better knowledge of tumoral extension and critical organs. Ultrasound during brachytherapy has led to the almost complete eradication of uterine perforation. In the future, a more systematic use of systems allowing optimization may induce a better dose distribution in the tumor as well as in the critical organs. Recent data provided information in favor of a better analysis in the relative role of dose-rate, total dose and treated volume and their influence on the local control and complication incidence. Concomitant radio-chemotherapy represents a standard in the treatment of patients with tumoral size exceeding 4 cm. Some questions still remain: is concomitant chemotherapy of benefit during brachytherapy? Is there any place for complementary surgery, specially in patients with complete response after external irradiation with concomitant chemotherapy and brachytherapy? In order to answer the former question, a phase III randomized trial is going to start, with the Federation Nationale des Centres de Lutte Contre le Cancer as a promoter. (authors)

Improve definition of titanium tandems in MR-guided high dose rate brachytherapy for cervical cancer using proton density weighted MRI

International Nuclear Information System (INIS)

Hu, Yanle; Esthappan, Jacqueline; Mutic, Sasa; Richardson, Susan; Gay, Hiram A; Schwarz, Julie K; Grigsby, Perry W

2013-01-01

For cervical cancer patients treated with MR-guided high dose rate brachytherapy, the accuracy of radiation delivery depends on accurate localization of both tumors and the applicator, e.g. tandem and ovoid. Standard T2-weighted (T2W) MRI has good tumor-tissue contrast. However, it suffers from poor uterus-tandem contrast, which makes the tandem delineation very challenging. In this study, we evaluated the possibility of using proton density weighted (PDW) MRI to improve the definition of titanium tandems. Both T2W and PDW MRI images were obtained from each cervical cancer patient. Imaging parameters were kept the same between the T2W and PDW sequences for each patient except the echo time (90 ms for T2W and 5.5 ms for PDW) and the slice thickness (0.5 cm for T2W and 0.25 cm for PDW). Uterus-tandem contrast was calculated by the equation C = (S u -S t )/S u , where S u and S t represented the average signal in the uterus and the tandem, respectively. The diameter of the tandem was measured 1.5 cm away from the tip of the tandem. The tandem was segmented by the histogram thresholding technique. PDW MRI could significantly improve the uterus-tandem contrast compared to T2W MRI (0.42±0.24 for T2W MRI, 0.77±0.14 for PDW MRI, p=0.0002). The average difference between the measured and physical diameters of the tandem was reduced from 0.20±0.15 cm by using T2W MRI to 0.10±0.11 cm by using PDW MRI (p=0.0003). The tandem segmented from the PDW image looked more uniform and complete compared to that from the T2W image. Compared to the standard T2W MRI, PDW MRI has better uterus-tandem contrast. The information provided by PDW MRI is complementary to those provided by T2W MRI. Therefore, we recommend adding PDW MRI to the simulation protocol to assist tandem delineation process for cervical cancer patients

Magnetic resonance image-guided brachytherapy for cervical cancer. Prognostic factors for survival

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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

Dosimetric impact of interfraction catheter movement and organ motion on MRI/CT guided HDR interstitial brachytherapy for gynecologic cancer

International Nuclear Information System (INIS)

Rey, Felipe; Chang, Chang; Mesina, Carmen; Dixit, Nayha; Kevin Teo, Boon-Keng; Lin, Lilie L.

2013-01-01

Purpose: To determine the dosimetric impact of catheter movement for MRI/CT image guided high dose rate (HDR) interstitial brachytherapy (ISBT) for gynecologic cancers. Materials and methods: Ten patients were treated with HDR ISBT. The CTV and organs at risk were contoured using a postimplant MRI and CT. 5 fractions were delivered twice daily on 3 consecutive days. The first fraction was delivered on day 1 (d1), fraction 2–3 on d2 and fraction 4–5 on d3. MRI/CT was acquired prior to the second and fourth fractions. Four scenarios were modeled. (1) The d1 plan was applied to the d2 and d3 CT, using the updated catheter positions. (2) Replanning was performed for d2 and d3. (3) We applied the dwell positions/times from the d2 replan over the d3 CT and compared with a d3 CT replan. (4) Based on daily MRI, target volumes were recontoured and replanned. Dosimetry was analyzed for each plan and compared to the d1 dose distribution. Results: (1) When using the d1 plan on the d2 and d3 CT with the updated catheter positions, the mean CTV D90 was reduced from 93.4% on d1 to 89.3% (p = 0.08) on d2 and to 87.7% (p = 0.005) on d3. (2) Replanning on d2 and d3 compensated for catheter movement, mean CTV D90 of 95.4% on d2 and 94.6% (p = 0.36) on d3. (3) When compared to the replan of d2 applied on the d3 CT vs the d3 replan, there was no significant difference in coverage, mean CTV D90 of 90.9% (p = 0.09). (4) Reoptimization based on daily MRI, significantly improved the CTV coverage for each day. The mean D2 cc for the rectum was significantly higher with model 1 vs model 3 59.1 ± 4.7 vs 60.9 ± 4.8 (p = 0.04) Gy EQD2. There were no significant differences in D2 cc of bladder and sigmoid between models. Conclusions: Interfraction dosimetric changes significantly decreased the CTV coverage of the third day. Rather than replanning on each day, replanning on the day 2 CT before the second or third fraction would give an optimal solution that would compensate for

Robotic Prostate Biopsy in Closed MRI Scanner

National Research Council Canada - National Science Library

Fischer, Gregory

2008-01-01

.... This work enables prostate brachytherapy and biopsy procedures in standard high-field diagnostic MRI scanners through the development of a robotic needle placement device specifically designed...

Development and clinical implementation of a new template for MRI-based intracavitary/interstitial gynecologic brachytherapy for locally advanced cervical cancer: from CT-based MUPIT to the MRI compatible Template Benidorm. Ten years of experience

Directory of Open Access Journals (Sweden)

Silvia Rodríguez Villalba

2016-10-01

Full Text Available Purpose : To study outcome and toxicity in 59 patients with locally advanced cervix carcinoma treated with computed tomography (CT-based Martinez universal perineal interstitial template (MUPIT and the new magnetic resonance imaging (MRI-compatible template Benidorm (TB. Material and methods: From December 2005 to October 2015, we retrospectively analyzed 34 patients treated with MUPIT and 25 treated with the TB. Six 4 Gy fractions were prescribed to the clinical target volume (CTV combined with external beam radiotherapy (EBRT. The organs at risk (OARs and the CTV were delineated by CT scan in the MUPIT implants and by MRI in the TB implants. Dosimetry was CT-based for MUPIT and exclusively MRI-based for TB. Dose values were biologically normalized to equivalent doses in 2 Gy fractions (EQD2. Results : Median CTV volumes were 163.5 cm3 for CT-based MUPIT (range 81.8-329.4 cm3 and 91.9 cm3 for MRI-based TB (range 26.2-161 cm3. Median D90 CTV (EBRT + BT was 75.8 Gy for CT-based MUPIT (range 69-82 Gy and 78.6 Gy for MRI-based TB (range 62.5-84.2. Median D2cm3 for the rectum was 75.3 Gy for CT-based MUPIT (range 69.8-132.1 Gy and 69.9 Gy for MRI-based TB (range 58.3-83.7 Gy. Median D2cm3 for the bladder was 79.8 Gy for CT-based MUPIT (range 71.2-121.1 Gy and 77.1 Gy for MRI-based TB (range 60.5-90.8 Gy. Local control (LC was 88%. Overall survival (OS, disease free survival (DFS, and LC were not statistically significant in either group. Patients treated with CT-based MUPIT had a significantly higher percentage of rectal bleeding G3 (p = 0.040 than those treated with MRI-based TB, 13% vs. 2%. Conclusions : Template Benidorm treatment using MRI-based dosimetry provides advantages of MRI volume definition, and allows definition of smaller volumes that result in statistically significant decreased rectal toxicity compared to that seen with CT-based MUPIT treatment.

American brachytherapy society (ABS) guidelines for brachytherapy of esophageal cancer

International Nuclear Information System (INIS)

Nag, Subir; Gaspar, Laurie; Herskovic, Arnold; Mantravadi, Prasad; Speiser, Burton

1996-01-01

Introduction: There is wide variation in the indications, techniques, treatment regimens and dosimetry being used to treat cancer of the esophagus and no guidelines exist for optimal therapy. Methods: The Clinical Research Committee of the ABS met to formulate consensus guidelines for brachytherapy in esophageal cancer. Results: Good candidates for brachytherapy include patients with unifocal disease, with thoracic tumor 10 cm primary regional lymph adenopathy or tumor located in the gastro-esophageal junction or cervical esophagus. Contraindications include tracheo-esophageal fistula or stenosis that cannot be by-passed. The esophageal or nasogastric tube inserted should have a diameter of 6-10 mm whenever possible. If 5FU-based chemotherapy and 50 Gy external beam (EBRT) are used, it is suggested that the low dose rate brachytherapy (LDR) dose be 20 Gy at 0.4-1 Gy/hr, prescribed at 1 cm from the source. If high dose rate (HDR) is used, the dose recommended is 10 Gy in 2 weekly fractions of 5 Gy each, given after EBRT. Chemotherapy is not usually given concurrently with brachytherapy, and when it is, the brachytherapy dose is reduced. The length of esophagus treated by brachytherapy includes the post-EBRT involved area and a 1-2 cm margin proximally and distally. Supportive care, given during EBRT includes an antifungal agent (e.g., diflucan) and carafate. Gradual dilatation of the esophagus is required post-treatment for esophageal strictures. Conclusion: Guidelines were developed for brachytherapy in esophageal cancer. As more clinical data becomes available, these guidelines will be updated by the ABS

American brachytherapy society (ABS) consensus guidelines for brachytherapy of esophageal cancer

International Nuclear Information System (INIS)

Gaspar, Laurie E.; Nag, Subir; Herskovic, Arnold; Mantravadi, Rao; Speiser, Burton

1997-01-01

Introduction: There is wide variation in the indications, treatment regimens, and dosimetry for brachytherapy in the treatment of cancer of the esophagus. No guidelines for optimal therapy currently exist. Methods and Materials: Utilizing published reports and clinical experience, representatives of the Clinical Research Committee of the American Brachytherapy Society (ABS) formulated guidelines for brachytherapy in esophageal cancer. Results: Recommendations were made for brachytherapy in the definitive and palliative treatment of esophageal cancer. (A) Definitive treatment: Good candidates for brachytherapy include patients with unifocal thoracic adeno- or squamous cancers ≤ 10 cm in length, with no evidence of intra-abdominal or metastatic disease. Contraindications include tracheal or bronchial involvement, cervical esophagus location, or stenosis that cannot be bypassed. The esophageal brachytherapy applicator should have an external diameter of 6-10 mm. If 5FU-based chemotherapy and 45-50-Gy external beam are used, recommended brachytherapy is either: (i) HDR 10 Gy in two weekly fractions of 5 Gy each; or (ii) LDR 20 Gy in a single course at 0.4-1 Gy/hr. All doses are specified 1 cm from the midsource or middwell position. Brachytherapy should follow external beam radiation therapy and should not be given concurrently with chemotherapy. (B) Palliative treatment: Patients with adeno- or squamous cancers of the thoracic esophagus with distant metastases or unresectable local disease progression/recurrence after definitive radiation treatment should be considered for brachytherapy with palliative intent. After limited dose (30 Gy) EBRT, the recommended brachytherapy is either: (i) HDR 10-14 Gy in one or two fractions; or (ii) LDR 20-25 Gy in a single course at 0.4-1 Gy/hr. The need for external beam radiation in newly diagnosed patients with a life expectancy of less than 3 months is controversial. In these cases, HDR of 15-20 Gy in two to four fractions or

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

Science.gov (United States)

Ruotsalainen, Henri; Miettinen, Kaisa; Palmgren, Jan-Erik; Lahtinen, Tapani

2010-08-01

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.

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

International Nuclear Information System (INIS)

Ruotsalainen, Henri; Miettinen, Kaisa; Palmgren, Jan-Erik; Lahtinen, Tapani

2010-01-01

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.

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.

SU-F-T-47: MRI T2 Exclusive Based Planning Using the Endocavitary/interstitial Gynecological Benidorm Applicator: A Proposed TPS Library and Preplan Efficient Methodology

International Nuclear Information System (INIS)

Richart, J; Otal, A; Rodriguez, S; Santos, M; Perez-Calatayud, J

2016-01-01

Purpose: ABS and GEC-ESTRO have recommended MRI T2 for image guided brachytherapy. Recently, a new applicator (Benidorm Template, TB) has been developed in our Department (Rodriguez et al 2015). TB is fully MRI compatible because the Titanium needles and it allows the use of intrauterine tandem. Currently, TPS applicators library are not currently available for non-rigid applicators in case of interstitial component as the TB.The purpose of this work is to present the development of a library for the TB, together with its use on a pre-planning technique. Both new goals allow a very efficient and exclusive T2 MRI based planning clinical TB implementation. Methods: The developed library has been implemented in Oncentra Brachytherapy TPS, version 4.3.0 (Elekta) and now is being implemented on Sagiplan v 2.0 TPS (Eckert&Ziegler BEBIG). To model the TB, free and open software named FreeCAD and MeshLab have been used. The reconstruction process is based on three inserted A-vitamin pellets together with the data provided by the free length. The implemented preplanning procedure is as follow: 1) A MRI T2 acquisition is performed with the template in place just with the vaginal cylinder (no uterine tube nor needles). 2) The CTV is drawn and the required needles are selected using a developed Java based application and 3) A post-implant MRI T2 is performed. Results: This library procedure has been successfully applied by now in 25 patients. In this work the use of the developed library will be illustrated with clinical examples. The preplanning procedure has been applied by now in 6 patients, having significant advantages: needle depth estimation, needle positions and number are optimized a priori, time saving, etc Conclusion: TB library and pre-plan techniques are feasible and very efficient and their use will be illustrated in this work.

SU-F-T-47: MRI T2 Exclusive Based Planning Using the Endocavitary/interstitial Gynecological Benidorm Applicator: A Proposed TPS Library and Preplan Efficient Methodology

Energy Technology Data Exchange (ETDEWEB)

Richart, J; Otal, A; Rodriguez, S; Santos, M [Clinica Benidorm, Benidorm, Alicante (Spain); Perez-Calatayud, J [Clinica Benidorm, Benidorm, Alicante (Spain); Hospital La Fe, Valencia (Spain)

2016-06-15

Purpose: ABS and GEC-ESTRO have recommended MRI T2 for image guided brachytherapy. Recently, a new applicator (Benidorm Template, TB) has been developed in our Department (Rodriguez et al 2015). TB is fully MRI compatible because the Titanium needles and it allows the use of intrauterine tandem. Currently, TPS applicators library are not currently available for non-rigid applicators in case of interstitial component as the TB.The purpose of this work is to present the development of a library for the TB, together with its use on a pre-planning technique. Both new goals allow a very efficient and exclusive T2 MRI based planning clinical TB implementation. Methods: The developed library has been implemented in Oncentra Brachytherapy TPS, version 4.3.0 (Elekta) and now is being implemented on Sagiplan v 2.0 TPS (Eckert&Ziegler BEBIG). To model the TB, free and open software named FreeCAD and MeshLab have been used. The reconstruction process is based on three inserted A-vitamin pellets together with the data provided by the free length. The implemented preplanning procedure is as follow: 1) A MRI T2 acquisition is performed with the template in place just with the vaginal cylinder (no uterine tube nor needles). 2) The CTV is drawn and the required needles are selected using a developed Java based application and 3) A post-implant MRI T2 is performed. Results: This library procedure has been successfully applied by now in 25 patients. In this work the use of the developed library will be illustrated with clinical examples. The preplanning procedure has been applied by now in 6 patients, having significant advantages: needle depth estimation, needle positions and number are optimized a priori, time saving, etc Conclusion: TB library and pre-plan techniques are feasible and very efficient and their use will be illustrated in this work.

Value of Magnetic Resonance Imaging Without or With Applicator in Place for Target Definition in Cervix Cancer Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Pötter, Richard [Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna (Austria); Federico, Mario [Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna, Vienna (Austria); Department of Radiation Oncology, Gran Canaria University Hospital, Las Palmas de Gran Canaria (Spain); Sturdza, Alina [Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna, Vienna (Austria); Fotina, Irina [Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna, Vienna (Austria); Institute of Physics and Technology, Tomsk Polytechnic University, Tomsk Oblast (Russian Federation); Hegazy, Neamat [Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna, Vienna (Austria); Department of Clinical Oncology, Medical University of Alexandria, Alexandria (Egypt); Schmid, Maximilian; Kirisits, Christian [Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna (Austria); Nesvacil, Nicole, E-mail: nicole.nesvacil@meduniwien.ac.at [Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna (Austria)

2016-03-01

Purpose: To define, in the setting of cervical cancer, to what extent information from additional pretreatment magnetic resonance imaging (MRI) without the brachytherapy applicator improves conformity of CT-based high-risk clinical target volume (CTV{sub HR}) contours, compared with the MRI for various tumor stages (International Federation of Gynecology and Obstetrics [FIGO] stages I-IVA). Methods and Materials: The CTV{sub HR} was contoured in 39 patients with cervical cancer (FIGO stages I-IVA) (1) on CT images based on clinical information (CTV{sub HR}-CT{sub Clinical}) alone; and (2) using an additional MRI before brachytherapy, without the applicator (CTV{sub HR}-CT{sub pre-BT} {sub MRI}). The CT contours were compared with reference contours on MRI with the applicator in place (CTV{sub HR}-MRI{sub ref}). Width, height, thickness, volumes, and topography were analyzed. Results: The CT-MRI{sub ref} differences hardly varied in stage I tumors (n=8). In limited-volume stage IIB and IIIB tumors (n=19), CTV{sub HR}-CT{sub pre-BT} {sub MRI}–MRI{sub ref} volume differences (2.6 cm{sup 3} [IIB], 7.3 cm{sup 3} [IIIB]) were superior to CTV{sub HR}-CT{sub Clinical}–MRI{sub ref} (11.8 cm{sup 3} [IIB], 22.9 cm{sup 3} [IIIB]), owing to significant improvement of height and width (P<.05). In advanced disease (n=12), improved agreement with MR volume, width, and height was achieved for CTV{sub HR}-CT{sub pre-BT} {sub MRI}. In 5 of 12 cases, MRI{sub ref} contours were partly missed on CT. Conclusions: Pre-BT MRI helps to define CTV{sub HR} before BT implantation appropriately, if only CT images with the applicator in place are available for BT planning. Significant improvement is achievable in limited-volume stage IIB and IIIB tumors. In more advanced disease (extensive IIB to IVA), improvement of conformity is possible but may be associated with geographic misses. Limited impact on precision of CTV{sub HR}-CT is expected in stage IB tumors.

Clinical Investigations of a CT-based reconstruction and 3D-Treatment planning system in interstitial brachytherapy

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Kolotas, C; Zamboglou, N [Strahlenklinik, Stadtische Kliniken Offenbach, Offenbach (Germany)

1999-12-31

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 clinically 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 the optimisation and calculation of dose distribution has been devised. The planning target volume(s) are defined as sets of points using contouring tools and are for optimisation of the 3D dose distribution. Dose-volume histogram-based analysis of the dose distribution 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 tumour and anatomical localizations in 197 patients between 1996 and 1997. Results : The accuracy of the CT reconstruction was tested using a quality assurance phantom an an interstitial implant of 12 needles and compared with the results of reconstruction using radiographs[hs. Both methods give comparable results with regard to accuracy. The CT based reconstruction was faster. Clinical feasibility has been proven in pre-irradiated recurrences of brain tumour, in pre-treated recurrences or metastatic disease, and in breast carcinomas. The tumour volume treated ranged from 5.1 - 2741 cm3. Analysis of the implant quality showed a slight significant lower COIN value for the bone implants, but no differences in respect to the planning target volume. Conclusions : With the integration of CT imaging in the treatment planning and documentation of brachytherapy, we have a new CT based quality assurance method to evaluate

Clinical Investigations of a CT-based reconstruction and 3D-Treatment planning system in interstitial brachytherapy

International Nuclear Information System (INIS)

Kolotas, C.; Zamboglou, N.

1998-01-01

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 clinically 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 the optimisation and calculation of dose distribution has been devised. The planning target volume(s) are defined as sets of points using contouring tools and are for optimisation of the 3D dose distribution. Dose-volume histogram-based analysis of the dose distribution 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 tumour and anatomical localizations in 197 patients between 1996 and 1997. Results : The accuracy of the CT reconstruction was tested using a quality assurance phantom an an interstitial implant of 12 needles and compared with the results of reconstruction using radiographs[hs. Both methods give comparable results with regard to accuracy. The CT based reconstruction was faster. Clinical feasibility has been proven in pre-irradiated recurrences of brain tumour, in pre-treated recurrences or metastatic disease, and in breast carcinomas. The tumour volume treated ranged from 5.1 - 2741 cm3. Analysis of the implant quality showed a slight significant lower COIN value for the bone implants, but no differences in respect to the planning target volume. Conclusions : With the integration of CT imaging in the treatment planning and documentation of brachytherapy, we have a new CT based quality assurance method to evaluate

Applicability and dosimetric impact of ultrasound-based preplanning in high-dose-rate brachytherapy of prostate cancer

International Nuclear Information System (INIS)

Aebersold, D.M.; Isaak, B.; Behrensmeier, F.; Kolotas, C.; Mini, R.; Greiner, R.H.; Thalmann, G.; Kranzbuehler, H.

2004-01-01

Background and purpose: analyses of permanent brachytherapy seed implants of the prostate have demonstrated that the use of a preplan may lead to a considerable decrease of dosimetric implant quality. The authors aimed to determine whether the same drawbacks of preplanning also apply to high-dose-rate (HDR) brachytherapy. Patients and methods: 15 patients who underwent two separate HDR brachytherapy implants in addition to external-beam radiation therapy for advanced prostate cancer were analyzed. A pretherapeutic transrectal ultrasound was performed in all patients to generate a preplan for the first brachytherapy implant. For the second brachytherapy, a subset of patients were treated by preplans based on the ultrasound from the first brachytherapy implant. Preplans were compared with the respective postplans assessing the following parameters: coverage index, minimum target dose, homogeneity index, and dose exposure of organs at risk. The prostate geometries (volume, width, height, length) were compared as well. Results: at the first brachytherapy, the matching between the preplan and actual implant geometry was sufficient in 47% of the patients, and the preplan could be applied. The dosimetric implant quality decreased considerably: the mean coverage differed by -0.11, the mean minimum target dose by -0.15, the mean homogeneity index by -0.09. The exposure of organs at risk was not substantially altered. At the second brachytherapy, all patients could be treated by the preplan; the differences between the implant quality parameters were less pronounced. The changes of prostate geometry between preplans and postplans were considerable, the differences in volume ranging from -8.0 to 13.8 cm 3 and in dimensions (width, height, length) from -1.1 to 1.0 cm. Conclusion: preplanning in HDR brachytherapy of the prostate is associated with a substantial decrease of dosimetric implant quality, when the preplan is based on a pretherapeutic ultrasound. The implant quality

Comparison and Consensus Guidelines for Delineation of Clinical Target Volume for CT- and MR-Based Brachytherapy in Locally Advanced Cervical Cancer

International Nuclear Information System (INIS)

Viswanathan, Akila N.; Erickson, Beth; Gaffney, David K.; Beriwal, Sushil; Bhatia, Sudershan K.; Lee Burnett, Omer; D'Souza, David P.; Patil, Nikhilesh; Haddock, Michael G.; Jhingran, Anuja; Jones, Ellen L.; Kunos, Charles A.; Lee, Larissa J.; Lin, Lilie L.; Mayr, Nina A.; Petersen, Ivy; Petric, Primoz; Portelance, Lorraine; Small, William; Strauss, Jonathan B.

2014-01-01

Objective: To create and compare consensus clinical target volume (CTV) contours for computed tomography (CT) and 3-Tesla (3-T) magnetic resonance (MR) image-based cervical-cancer brachytherapy. Methods and Materials: Twenty-three experts in gynecologic radiation oncology contoured the same 3 cervical cancer brachytherapy cases: 1 stage IIB near-complete response (CR) case with a tandem and ovoid, 1 stage IIB partial response (PR) case with tandem and ovoid with needles, and 1 stage IB2 CR case with a tandem and ring applicator. The CT contours were completed before the MRI contours. These were analyzed for consistency and clarity of target delineation using an expectation maximization algorithm for simultaneous truth and performance level estimation (STAPLE), with κ statistics as a measure of agreement between participants. The conformity index was calculated for each of the 6 data sets. Dice coefficients were generated to compare the CT and MR contours of the same case. Results: For all 3 cases, the mean tumor volume was smaller on MR than on CT (P<.001). The κ and conformity index estimates were slightly higher for CT, indicating a higher level of agreement on CT. The Dice coefficients were 89% for the stage IB2 case with a CR, 74% for the stage IIB case with a PR, and 57% for the stage IIB case with a CR. Conclusion: In a comparison of MR-contoured with CT-contoured CTV volumes, the higher level of agreement on CT may be due to the more distinct contrast medium visible on the images at the time of brachytherapy. MR at the time of brachytherapy may be of greatest benefit in patients with large tumors with parametrial extension that have a partial or complete response to external beam. On the basis of these results, a 95% consensus volume was generated for CT and for MR. Online contouring atlases are available for instruction at (http://www.nrgoncology.org/Resources/ContouringAtlases/GYNCervicalBrachytherapy.aspx)

Comparison and Consensus Guidelines for Delineation of Clinical Target Volume for CT- and MR-Based Brachytherapy in Locally Advanced Cervical Cancer

Energy Technology Data Exchange (ETDEWEB)

Viswanathan, Akila N., E-mail: aviswanathan@lroc.harvard.edu [Brigham and Women' s Hospital/Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Erickson, Beth [Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Gaffney, David K. [University of Utah Huntsman Cancer Hospital, Salt Lake City, Utah (United States); Beriwal, Sushil [University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania (United States); Bhatia, Sudershan K. [University of Iowa, Iowa City, Iowa (United States); Lee Burnett, Omer [University of Alabama, Birmingham, Alabama (United States); D' Souza, David P.; Patil, Nikhilesh [London Health Sciences Centre and Western University, London, Ontario (Canada); Haddock, Michael G. [Mayo Medical Center, Rochester, Minnesota (United States); Jhingran, Anuja [University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Jones, Ellen L. [University of North Carolina, Chapel Hill, North Carolina (United States); Kunos, Charles A. [Case Western Reserve University, Cleveland, Ohio (United States); Lee, Larissa J. [Brigham and Women' s Hospital/Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Lin, Lilie L. [University of Pennsylvania, Philadelphia, Pennsylvania (United States); Mayr, Nina A. [University of Washington, Seattle, Washington (United States); Petersen, Ivy [Mayo Medical Center, Rochester, Minnesota (United States); Petric, Primoz [Division of Radiotherapy, Institute of Oncology Ljubljana, Ljubljana (Slovenia); Department of Radiation Oncology, National Center for Cancer Care and Research, Doha (Qatar); Portelance, Lorraine [University of Miami Miller School of Medicine, Miami, Florida (United States); Small, William [Loyola University Strich School of Medicine, Chicago, Illinois (United States); Strauss, Jonathan B. [The Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, Illinois (United States); and others

2014-10-01

Objective: To create and compare consensus clinical target volume (CTV) contours for computed tomography (CT) and 3-Tesla (3-T) magnetic resonance (MR) image-based cervical-cancer brachytherapy. Methods and Materials: Twenty-three experts in gynecologic radiation oncology contoured the same 3 cervical cancer brachytherapy cases: 1 stage IIB near-complete response (CR) case with a tandem and ovoid, 1 stage IIB partial response (PR) case with tandem and ovoid with needles, and 1 stage IB2 CR case with a tandem and ring applicator. The CT contours were completed before the MRI contours. These were analyzed for consistency and clarity of target delineation using an expectation maximization algorithm for simultaneous truth and performance level estimation (STAPLE), with κ statistics as a measure of agreement between participants. The conformity index was calculated for each of the 6 data sets. Dice coefficients were generated to compare the CT and MR contours of the same case. Results: For all 3 cases, the mean tumor volume was smaller on MR than on CT (P<.001). The κ and conformity index estimates were slightly higher for CT, indicating a higher level of agreement on CT. The Dice coefficients were 89% for the stage IB2 case with a CR, 74% for the stage IIB case with a PR, and 57% for the stage IIB case with a CR. Conclusion: In a comparison of MR-contoured with CT-contoured CTV volumes, the higher level of agreement on CT may be due to the more distinct contrast medium visible on the images at the time of brachytherapy. MR at the time of brachytherapy may be of greatest benefit in patients with large tumors with parametrial extension that have a partial or complete response to external beam. On the basis of these results, a 95% consensus volume was generated for CT and for MR. Online contouring atlases are available for instruction at (http://www.nrgoncology.org/Resources/ContouringAtlases/GYNCervicalBrachytherapy.aspx)

Innovation in gynaecological brachytherapy: new technologies, pulse dose-rate brachytherapy, image, definition of new volumes of interest and their impact on dosimetry: application in a clinical research programme 'S.T.I.C.'

International Nuclear Information System (INIS)

Haie-Meder, C.; Peiffert, D.

2006-01-01

Brachytherapy plays a fundamental role in the therapeutic approach of patients with stage I-IV cervical carcinoma. Technical modalities have evolved during the last decades: stepping source technology, imaging modalities development, specially IMN, treatment planning system integrating 3D images. Images from CT-Scan and MRI have contributed to a better knowledge of tumoral extension and critical organs. CT and/or MRI compatible applicators allow a sectional image based approach with a better definition of tumour volume compared to traditional approaches. The introduction of 3D image based approach for GTV and CTV requires new definitions and a common language. In 2000, a working group within GEC-ESTRO was created to support 3D image based 3D treatment planning approach in cervix cancer BT. The task was to determine a common terminology enabling various groups to use a common language. Recommendations were described and proposed based on clinical experience and dosimetric concepts of different institutions. Two CTVs were described en relation to the risk for recurrence: high-risk CTV and intermediate risk CTV. In order to better define the role of such definitions and their potential impact on the complication incidence in patients with cervical cancer, a special French programme was developed. The aim of this programme is to study the incidence of the severe 2-year complication rate in two comparable patient populations: one population is treated using PDR brachytherapy with CT-Scan or MRI with the applicators in place allowing a 3D dosimetry with optimization, the second population is treated using standard X-rays radiographs, without any delineation of the target nor optimisation. Each population arm includes 425 patients. A medico-economic assessment is performed, allowing a real cost of the most sophisticated approach compared to a historical dosimetric system. (author)

Value of Magnetic Resonance Imaging Without or With Applicator in Place for Target Definition in Cervix Cancer Brachytherapy

International Nuclear Information System (INIS)

Pötter, Richard; Federico, Mario; Sturdza, Alina; Fotina, Irina; Hegazy, Neamat; Schmid, Maximilian; Kirisits, Christian; Nesvacil, Nicole

2016-01-01

Purpose: To define, in the setting of cervical cancer, to what extent information from additional pretreatment magnetic resonance imaging (MRI) without the brachytherapy applicator improves conformity of CT-based high-risk clinical target volume (CTV_H_R) contours, compared with the MRI for various tumor stages (International Federation of Gynecology and Obstetrics [FIGO] stages I-IVA). Methods and Materials: The CTV_H_R was contoured in 39 patients with cervical cancer (FIGO stages I-IVA) (1) on CT images based on clinical information (CTV_H_R-CT_C_l_i_n_i_c_a_l) alone; and (2) using an additional MRI before brachytherapy, without the applicator (CTV_H_R-CT_p_r_e_-_B_T _M_R_I). The CT contours were compared with reference contours on MRI with the applicator in place (CTV_H_R-MRI_r_e_f). Width, height, thickness, volumes, and topography were analyzed. Results: The CT-MRI_r_e_f differences hardly varied in stage I tumors (n=8). In limited-volume stage IIB and IIIB tumors (n=19), CTV_H_R-CT_p_r_e_-_B_T _M_R_I–MRI_r_e_f volume differences (2.6 cm"3 [IIB], 7.3 cm"3 [IIIB]) were superior to CTV_H_R-CT_C_l_i_n_i_c_a_l–MRI_r_e_f (11.8 cm"3 [IIB], 22.9 cm"3 [IIIB]), owing to significant improvement of height and width (P<.05). In advanced disease (n=12), improved agreement with MR volume, width, and height was achieved for CTV_H_R-CT_p_r_e_-_B_T _M_R_I. In 5 of 12 cases, MRI_r_e_f contours were partly missed on CT. Conclusions: Pre-BT MRI helps to define CTV_H_R before BT implantation appropriately, if only CT images with the applicator in place are available for BT planning. Significant improvement is achievable in limited-volume stage IIB and IIIB tumors. In more advanced disease (extensive IIB to IVA), improvement of conformity is possible but may be associated with geographic misses. Limited impact on precision of CTV_H_R-CT is expected in stage IB tumors.

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

SU-E-J-215: Towards MR-Only Image Guided Identification of Calcifications and Brachytherapy Seeds: Application to Prostate and Breast LDR Implant Dosimetry

Energy Technology Data Exchange (ETDEWEB)

Elzibak, A; Fatemi-Ardekani, A; Soliman, A; Mashouf, S; Safigholi, H; Ravi, A; Morton, G; Song, WY [Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Han, D [Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); University of California, San Diego, La Jolla, CA (United States)

2015-06-15

Purpose: To identify and analyze the appearance of calcifications and brachytherapy seeds on magnitude and phase MRI images and to investigate whether they can be distinguished from each other on corrected phase images for application to prostate and breast low dose rate (LDR) implant dosimetry. Methods: An agar-based gel phantom containing two LDR brachytherapy seeds (Advantage Pd-103, IsoAid, 0.8mm diameter, 4.5mm length) and two spherical calcifications (large: 7mm diameter and small: 4mm diameter) was constructed and imaged on a 3T Philips MR scanner using a 16-channel head coil and a susceptibility weighted imaging (SWI) sequence (2mm slices, 320mm FOV, TR/ TE= 26.5/5.3ms, 15 degree flip angle). The phase images were unwrapped and corrected using a 32×32, 2D Hanning high pass filter to remove background phase noise. Appearance of the seeds and calcifications was assessed visually and quantitatively using Osirix (http://www.osirix-viewer.com/). Results: As expected, calcifications and brachytherapy seeds appeared dark (hypointense) relative to the surrounding gel on the magnitude MRI images. The diameter of each seed without the surrounding artifact was measured to be 0.1 cm on the magnitude image, while diameters of 0.79 and 0.37 cm were measured for the larger and smaller calcifications, respectively. On the corrected phase images, the brachytherapy seeds and the calcifications appeared bright (hyperintense). The diameter of the seeds was larger on the phase images (0.17 cm) likely due to the dipole effect. Conclusion: MRI has the best soft tissue contrast for accurate organ delineation leading to most accurate implant dosimetry. This work demonstrated that phase images can potentially be useful in identifying brachytherapy seeds and calcifications in the prostate and breast due to their bright appearance, which helps in their visualization and quantification for accurate dosimetry using MR-only. Future work includes optimizing phase filters to best identify

MRI-assisted versus conventional treatment planning in brachytherapy of cervical and endometrial carcinoma: The impact of individual anatomy on dose distribution in target volume and organs at risk

International Nuclear Information System (INIS)

Wulf, Joern; Sauer, Otto A.; Herbolsheimer, Michael; Oppitz, Ulrich; Flentje, Michael

1996-01-01

Objective: Dose prescription and definition of target volume in brachytherapy of cervical and endometrial cancer are calculated to standard points as Manchester point A or point My(ometrium) in most centers. Calculation of doses to organs at risk mainly relies on ICRU-report 38. But standard dose prescription neglects individual patient anatomy. While MRI and CT had widespread impact on individual planning in external beam radiotherapy, there is still a minor influence on brachytherapy. The impact of individual anatomy on dose distribution in target volume and organs at risk demonstrates the objective of individual brachytherapy planning. Materials and Methods: 8 patients with cervical and 4 patients with endometrial carcinoma underwent MRI of the pelvis with in-situ applicators (ring-tandem applicators for cervical carcinoma and modified Heyman-capsules for endometrial carcinoma). T1w slices were angulated coronal and sagittal to get rectangular reproductions to applicator axis. Orthogonal or isocentric X-ray films for conventional treatment planning were done. MRI-information on target and organs at risk was transformed into coordinates relative to applicator axis and dose calculation on the database of conventional treatment planning was performed by Nucletron Planning System PLATO. Isodoses were projected into MRI slices. Prescribed dose to patients with cervical cancer was 8.5 Gy to point A resp. 10 Gy to point My (2cm below fundal myometrium and 2cm lateral applicator axis) in endometrial cancer. Results: Dose prescription to Manchester point A or point My represented in only 50% of cases uterine serosa. Instead of 2cm lateral of applicator axis, uterine surface ranged from 1.0 cm to 3.9 cm at the level of point A (mean 2.25 cm coronal and 1.77 cm sagittal) and from 1.5 cm to 4.4 cm at the level of point My (mean 2.7 cm coronal and 2.1 cm sagittal). Uterine volume ranged from 69 cc to 277 cc, mean volume was 150cc. Dose-volume histograms of patients with

Time course of late rectal- and urinary bladder side effects after MRI-guided adaptive brachytherapy for cervical cancer

Energy Technology Data Exchange (ETDEWEB)

Georg, P.; Georg, D.; Poetter, R.; Doerr, W. [Medical University Vienna/ AKH Wien (Austria). Dept. of Radiooncology; Medical University Vienna (Austria). Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology; Medical University Vienna/ AKH Wien (Austria). Comprehensive Cancer Centre; Boni, A.; Ghabuous, A. [Medical University Vienna/ AKH Wien (Austria). Dept. of Radiooncology; Goldner, G.; Schmid, M.P. [Medical University Vienna/ AKH Wien (Austria). Dept. of Radiooncology; Medical University Vienna/ AKH Wien (Austria). Comprehensive Cancer Centre

2013-07-15

Background and purpose: To analyze the time course of late rectal- and urinary bladder complications after brachytherapy for cervical cancer and to compare the incidence- and prevalence rates thereof. Patients and methods: A total of 225 patients were treated with external-beam radiotherapy (EBRT) and magnetic resonance imaging (MRI)-guided brachytherapy with or without chemotherapy. Late side effects were assessed prospectively using the Late Effects in Normal Tissue - Subjective, Objective, Management and Analytic (LENT/SOMA) scale. The parameters analyzed were time to onset, duration, actuarial incidence- (occurrence of new side effects during a defined time period) and prevalence rates (side effects existing at a defined time point). Results: Median follow-up was 44 months. Side effects (grade 1-4) in rectum and bladder were present in 31 and 49 patients, 14 and 27 months (mean time to onset) after treatment, respectively. All rectal and 76 % of bladder side effects occurred within 3 years after radiotherapy. Mean duration of rectal events was 19 months; 81 % resolved within 3 years of their initial diagnosis. Mean duration of bladder side effects was 20 months; 61 % resolved within 3 years. The 3- and 5-year actuarial complication rates were 16 and 19 % in rectum and 18 and 28 % in bladder, respectively. The corresponding prevalence rates were 9 and 2 % (rectum) and 18 and 21 % (bladder), respectively. Conclusion: Late side effects after cervical cancer radiotherapy are partially reversible, but their time course is organ-dependent. The combined presentation of incidence- and prevalence rates provides the most comprehensive information. (orig.)

Time course of late rectal- and urinary bladder side effects after MRI-guided adaptive brachytherapy for cervical cancer

International Nuclear Information System (INIS)

Georg, P.; Georg, D.; Poetter, R.; Doerr, W.; Medical University Vienna; Medical University Vienna/ AKH Wien; Boni, A.; Ghabuous, A.; Goldner, G.; Schmid, M.P.; Medical University Vienna/ AKH Wien

2013-01-01

Background and purpose: To analyze the time course of late rectal- and urinary bladder complications after brachytherapy for cervical cancer and to compare the incidence- and prevalence rates thereof. Patients and methods: A total of 225 patients were treated with external-beam radiotherapy (EBRT) and magnetic resonance imaging (MRI)-guided brachytherapy with or without chemotherapy. Late side effects were assessed prospectively using the Late Effects in Normal Tissue - Subjective, Objective, Management and Analytic (LENT/SOMA) scale. The parameters analyzed were time to onset, duration, actuarial incidence- (occurrence of new side effects during a defined time period) and prevalence rates (side effects existing at a defined time point). Results: Median follow-up was 44 months. Side effects (grade 1-4) in rectum and bladder were present in 31 and 49 patients, 14 and 27 months (mean time to onset) after treatment, respectively. All rectal and 76 % of bladder side effects occurred within 3 years after radiotherapy. Mean duration of rectal events was 19 months; 81 % resolved within 3 years of their initial diagnosis. Mean duration of bladder side effects was 20 months; 61 % resolved within 3 years. The 3- and 5-year actuarial complication rates were 16 and 19 % in rectum and 18 and 28 % in bladder, respectively. The corresponding prevalence rates were 9 and 2 % (rectum) and 18 and 21 % (bladder), respectively. Conclusion: Late side effects after cervical cancer radiotherapy are partially reversible, but their time course is organ-dependent. The combined presentation of incidence- and prevalence rates provides the most comprehensive information. (orig.)

Income generated by women treated with magnetic resonance imaging-based brachytherapy: A simulation study evaluating the macroeconomic benefits of implementing a high-end technology in a public sector healthcare setting.

Science.gov (United States)

Chakraborty, Santam; Mahantshetty, Umesh; Chopra, Supriya; Lewis, Shirley; Hande, Vinod; Gudi, Shivakumar; Krishnatry, Rahul; Engineer, Reena; Shrivastava, Shyam Kishore

To estimate the difference in income generated if all women presenting in our institute over a 5-year period were treated with MRI-based image-guided brachytherapy (MR-IGBT) instead of conventional radiograph-based brachytherapy (CR-BT). Outcome data from 463 patients (94 treated with MR-IGBT) treated in our institute was used to simulate cumulative women-days of work and cumulative income over 5 years for 5526 patients expected to be treated in this period. The average daily income for a woman was derived from the National Sample Survey Organization (NSSO) survey data. Outcomes from both unmatched and propensity score-matched data sets were simulated. The cumulative income in 5 years ranged between Rs 101-168 million if all patients presenting at our institute underwent MR-IGBT. The simulated excess income ranged from Rs 4-45 million after 5 years, which represented 6-66% of the expenditure incurred for acquiring the required equipment and manpower for practicing exclusive MR-IGBT. Using outcome data from a prospective cohort of patients treated with MR-IGBT in our institute, we demonstrated that significant economic gains may be realized if MR-IGBT was used instead of CR-BT. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

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

Effect of pulse sequence parameter selection on signal strength in positive-contrast MRI markers for MRI-based prostate postimplant assessment

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Lim, Tze Yee [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 and The University of Texas at Houston Graduate School of Biomedical Sciences, 6767 Bertner Avenue, Houston, Texas 77030 (United States); Kudchadker, Rajat J., E-mail: rkudchad@mdanderson.org; Wang, Jihong; Ibbott, Geoffrey S. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 (United States); Stafford, R. Jason [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 (United States); MacLellan, Christopher [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 and The University of Texas at Houston Graduate School of Biomedical Sciences, 6767 Bertner Avenue, Houston, Texas 77030 (United States); Rao, Arvind [Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 (United States); Frank, Steven J. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 (United States)

2016-07-15

Purpose: For postimplant dosimetric assessment, computed tomography (CT) is commonly used to identify prostate brachytherapy seeds, at the expense of accurate anatomical contouring. Magnetic resonance imaging (MRI) is superior to CT for anatomical delineation, but identification of the negative-contrast seeds is challenging. Positive-contrast MRI markers were proposed to replace spacers to assist seed localization on MRI images. Visualization of these markers under varying scan parameters was investigated. Methods: To simulate a clinical scenario, a prostate phantom was implanted with 66 markers and 86 seeds, and imaged on a 3.0T MRI scanner using a 3D fast radiofrequency-spoiled gradient recalled echo acquisition with various combinations of scan parameters. Scan parameters, including flip angle, number of excitations, bandwidth, field-of-view, slice thickness, and encoding steps were systematically varied to study their effects on signal, noise, scan time, image resolution, and artifacts. Results: The effects of pulse sequence parameter selection on the marker signal strength and image noise were characterized. The authors also examined the tradeoff between signal-to-noise ratio, scan time, and image artifacts, such as the wraparound artifact, susceptibility artifact, chemical shift artifact, and partial volume averaging artifact. Given reasonable scan time and managable artifacts, the authors recommended scan parameter combinations that can provide robust visualization of the MRI markers. Conclusions: The recommended MRI pulse sequence protocol allows for consistent visualization of the markers to assist seed localization, potentially enabling MRI-only prostate postimplant dosimetry.

The PROSPER robot for prostate brachytherapy: design, development and preclinical evaluation

International Nuclear Information System (INIS)

Long, J.A.

2012-01-01

Objectives: reporting the design, development and experiments of a new robotic system for prostate brachytherapy including prostate tracking and MRI to Ultrasound registration. Material and methods: a robot for trans-perineal needle insertion has been developed. It includes the ability to track the prostate position and shape. Experiments on 90 targets inside 9 deformable phantoms have been conducted. A feasibility on 2 cadavers has also been performed. The robot had to place glass seeds simulating brachytherapy seeds as close as possible to physical targets included into the phantom or inside the prostates. A post-operative CT scan of the phantom or prostate was performed in order to measure the accuracy of the system. Results: the median accuracy was 2.73 mm with a median prostate motion of 5.46 mm. The accuracy in the base region was superior to the accuracy in the apex region (2.28 mm vs 3.83 mm, p≤0.01) and was not significantly different for horizontal or oblique needles (2.7 vs 2.82 mm, p=0.18). Cadaver experiments demonstrated that the approach was feasible and that the robot could be used in a real clinical environment. Conclusion: the robot for prostate brachytherapy is the first system enabling prostate tracking. Targets can be accurately reached despite prostate motion and deformation. It could be applied to focal therapy for prostate cancer. (author)

Overview of brachytherapy resources in Europe: A survey of patterns of care study for brachytherapy in Europe

International Nuclear Information System (INIS)

Guedea, Ferran; Ellison, Tracey; Venselaar, Jack; Borras, Josep Maria; Hoskin, Peter; Poetter, Richard; Heeren, Germaine; Nisin, Roselinne; Francois, Guy; Mazeron, Jean Jacques; Limbergen, Erik Van; Ventura, Montserrat; Taillet, Michel; Cottier, Brian

2007-01-01

Background and purpose: The Patterns of Care for Brachytherapy in Europe (PCBE) study is aimed at establishing a detailed information system on brachytherapy throughout Europe. Materials and methods: The questionnaire was web-based and the analysis used data from each radiotherapy department with brachytherapy. There were three groups: Group I with 19 countries (15 initial European Community (EC) countries plus Iceland, Monaco, Norway and Switzerland -EC+4-), Group II with 10 countries (New European Community countries -NEC-) and Group III with 14 countries (Other European Countries -OEC-). Results: In the European area there are 36 of 43 countries (85%) which achieved data collection from at least 50% of centres, and were included in the analysis. The tumour site that had the largest number of treated patients was gynaecological tumours. Several variations have been found in the mean number of patients treated per consultant radiation oncologist and physicist; and in the proportion of brachytherapy patients with gynaecology, prostate and breast tumours, by country and by European area. The provided data showed that the average number of brachytherapy patients per centre increased by 10% between 1997 and 2002. Conclusions: A European wide evaluation of brachytherapy practice using a web-based questionnaire is feasible and that there is considerable variation in both patterns of practice and available resources

Paddle-based rotating-shield brachytherapy

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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

Intravascular brachytherapy for peripheral vascular disease

Directory of Open Access Journals (Sweden)

Hagen, Anja

2008-09-01

vs. no brachytherapy after stenting did not show significant results for the rate of restenosis at six months. Both, early and late thrombotic occlusions appeared more frequently in the brachytherapy group. Health economic evaluation: Additional costs of brachytherapy were estimated to be 1,655 or 1,767 Euro according to the used G-DRG. The incremental cost-effectiveness ratio per avoided restenosis was calculated to be 8,484 Euro or 9,058 Euro for brachytherapy use after successful balloon dilatation, 19,027 Euro or 20,314 Euro for brachytherapy after PTA with optional stenting and -39,646 Euro or -48,330 Euro for brachytherapy after stenting. Discussion: Partially poor performing and reporting quality of the RCT exacerbate the interpretation and the transferability of the study results. The used methodical approach enables the highest evidence level for the determined results and presents a good approximation of the current brachytherapy related costs for the German health care system. Conclusions: Brachytherapy after successful balloon dilatation in PAOD can be recommended from a medical point of view for the reduction of the rate of restenosis at one year. However from a health economic view the answer is not yet clear. Based on the current data the use of brachytherapy after stenting in PAOD cannot be recommended neither from a medical nor from a health economic point of view. The informed consent of the patients is an important ethical aspect in the use of brachytherapy.

Use of 3D imaging and awareness of GEC-ESTRO recommendations for cervix cancer brachytherapy throughout Australia and New Zealand

International Nuclear Information System (INIS)

Dyk, S Van; Bernshaw, D.; Byram, D.

2010-01-01

Full text: A 2005 survey of practices indicated limited use of three dimensional (3D) imaging modalities and planning methods in cervix cancer brachytherapy in Australia and New Zealand. However, advancing technologies and published recommendations are influencing change. This survey aims to identify both changes in practice and awareness and uptake of Groupe European de Curietherapie of the European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) recommendations. Methods: A survey was emailed to all radiotherapy departments with brachytherapy facilities. Twenty departments practise brachytherapy for cancer of the cervix. The survey consisted of five questions enquiring about use and type of 3D imaging; rate of reimaging and replanning; and contouring, prescribing and reporting practices. Results: A 100% response rate was obtained. Sixty-five per cent of departments use 3D CT imaging to plan brachytherapy insertions. Thirty per cent of departments use two-dimensional ( 2D ) x-rays. Four departments (20%) use a combination of imaging modalities including CT, ultrasound and MRI. Sixtyfive per cent of departments reimage and replan for each insertion. Four departments (20%) contour, prescribe dose and report treatment according to GEC-ESTRO recommendations. Conclusions: There has been a marked increase in the use of 3D imaging and awareness of GEC-ESTRO recommendations. Implementation and reporting of image-based gynaecological brachytherapy is strongly dependent on local resources and infrastructure.

Accelerated partial breast irradiation utilizing balloon brachytherapy techniques

International Nuclear Information System (INIS)

Strauss, Jonathan B.; Dickler, Adam

2009-01-01

To overcome the barriers to BCT, methods of PBI in the setting of breast conservation have been explored. The method of PBI with the longest published follow-up is multi-catheter interstitial brachytherapy. Balloon-based brachytherapy with the MammoSite brachytherapy applicator was designed to simplify the brachytherapy procedure for PBI, enhance the reproducibility of the dosimetry, and improve patient comfort. The rates of local recurrence following PBI with the MammoSite applicator have been low, but there are few published reports and follow-up has been relatively short. The cosmetic outcomes and toxicity of MammoSite PBI are comparable to those seen after multicatheter-based PBI. Additional methods of balloon brachytherapy, including Xoft and SenoRx Contura have been developed. Finally, long-term follow-up after PBI is important for the welfare of individual patients and in order to establish the efficacy, late toxicity and cosmetic outcomes of this technique.

Diffusion Weighted MRI as a predictive tool for effect of radiotherapy in locally advanced cervical cancer

DEFF Research Database (Denmark)

Haack, Søren; Tanderup, Kari; Fokdal, Lars

Diffusion weighted MRI has shown great potential in diagnostic cancer imaging and may also have value for monitoring tumor response during radiotherapy. Patients with advanced cervical cancer are treated with external beam radiotherapy followed by brachytherapy. This study evaluates the value of DW......-MRI for predicting outcome of patients with advanced cervical cancer at time of brachytherapy. Volume of hyper-intensity on highly diffusion sensitive images and resulting ADC value for treatment responders and non-responders is compared. The change of ADC and volume of hyper-intensity over time of BT is also...

Use of MRI in interventions in head and neck surgery

International Nuclear Information System (INIS)

Schulz, T.; Schneider, J.P.; Schmidt, F.; Kahn, T.; Bootz, F.; Weber, A.; Weidenbach, H.; Heinke, W.; Koehler-Brock, A.

2001-01-01

Presentation of new concepts and applications of MR-guided head and neck surgery are presented. Examples of diagnostic and therapeutic procedures such as evaluation of transseptal tumor biopsies, placement of afterloading catheters for brachytherapy, and microscopic surgery of paranasal sinuses in the open MRI are discussed. Material and Methods: 24 MRI-guided ENT-procedures (14 transsphenoidal biopsies, one transnasal biopsy, 6 placements of brachytherapy catheters, and 3 operations of the paranasal sinuses) were performed in an open 0.5 T MR system. Results: localisation and/or extension of all lesions as well as the placement of biopsy needles or catheters were determined with great precision during the interventions. Conclusions: surgical risk and postoperative morbidity are significantly reduced in MR-guided surgery of the petroclival region and the region of head and neck compared to other, conventional methods. Thus, interventional MRI-guidance optimizes minimal invasive surgery and catheter placement in difficult anatomical regions like the petroclival region. (orig.) [de

[Radiologic follow-up after breast-conserving surgery: value of MRI examination of the breast].

Science.gov (United States)

Polgár, C; Forrai, G; Szabó, E; Riedl, E; Fodor, J; Fornet, B; Németh, G

1999-11-21

The aim of the study was to establish an objective method for evaluation the extent, topography and quantity of skin and soft tissue side effects after tele- and/or brachyradiotherapy of the conserved breast and to compare the sequales of different radiation methods. 26 patients operated on for T1-2 N0-1 breast cancer underwent the following kinds of postoperative radiotherapy: 1. 46-50 Gy whole breast teletherapy + 10-16 Gy electron boost (5 patients), 2. 46-50 Gy teletherapy + 10-15 Gy HDR brachytherapy boost (12 patients), 3. 46-50 Gy teletherapy (6 patients), 4. 36,4 Gy sole HDR brachytherapy of the tumour bed (5 patients). The postirradiation side effects were examined by MRI, mammogram, US and physical examination, as well. MRI was performed on a 0.5 T, double breast coil, with SE-T1, SE-T2 and 3D-GE sequences. The findings of MRI and mammography were compared to physically detectable side effects using the RTOG/EORTC late radiation morbidity scoring scheme. US is useful in the measurement of skin thickening and in the diagnosis of fat necrosis. Mammography and physical examination are very subjective and low specificity methods to evaluate postirradiation side effects. MRI is a suitable and more objective method to detect the real extent and quantity of skin thickening and fibrosis. The incidence of > or = G2 side effects of skin and breast parenchyma were 64.5 and 32.2%, respectively. The differences between the side effects of whole breast irradiation and sole brachytherapy of the tumour bed are also clearly demonstrated. Brachytherapy alone is feasible without compromising cosmetic results. The authors established the MRI criteria for categorization the extent and grade of skin thickening and fibrosis (focal vs diffuse, grade 1-4). Breast MRI is an objective tool for assisting to the evaluation of the side effects of postoperative radiotherapy.

The american brachytherapy society recommendations for permanent prostate brachytherapy postimplant dosimetric analysis

International Nuclear Information System (INIS)

Nag, Subir; Bice, William; Wyngaert, Keith de; Prestidge, Bradley; Stock, Richard; Yu Yan

2000-01-01

Purpose: The purpose of this report is to establish guidelines for postimplant dosimetric analysis of permanent prostate brachytherapy. Methods: Members of the American Brachytherapy Society (ABS) with expertise in prostate dosimetry evaluation performed a literature review and supplemented with their clinical experience formulated guidelines for performing and analyzing postimplant dosimetry of permanent prostate brachytherapy. Results: The ABS recommends that postimplant dosimetry should be performed on all patients undergoing permanent prostate brachytherapy for optimal patient care. At present, computed tomography (CT)-based dosimetry is recommended, based on availability cost and the ability to image the prostate as well as the seeds. Additional plane radiographs should be obtained to verify the seed count. Until the ideal postoperative interval for CT scanning has been determined, each center should perform dosimetric evaluation of prostate implants at a consistent postoperative interval. This interval should be reported. Isodose displays should be obtained at 50%, 80%, 90%, 100%, 150%, and 200% of the prescription dose and displayed on multiple cross-sectional images of the prostate. A dose-volume histogram (DVH) of the prostate should be performed and the D 90 (dose to 90% of the prostate gland) reported by all centers. Additionally, the D 80, D 100, the fractional V 80, V 90, V 100, V 150, and V 200, (i.e., the percentage of prostate volume receiving 80%, 90%, 100%, 150%, and 200% of the prescribed dose, respectively), the rectal, and urethral doses should be reported and ultimately correlated with clinical outcome in the research environment. On-line real-time dosimetry, the effects of dose heterogeneity, and the effects of tissue heterogeneity need further investigation. Conclusion: It is essential that postimplant dosimetry should be performed on all patients undergoing permanent prostate brachytherapy. Guidelines were established for the performance

A dose planning study on applicator guided stereotactic IMRT boost in combination with 3D MRI based brachytherapy in locally advanced cervical cancer

International Nuclear Information System (INIS)

Assenholt, Marianne S.; Petersen, Joergen B.; Nielsen, Soeren K.; Lindegaard, Jacob C.; Tanderup, Kari

2008-01-01

Purpose. Locally advanced cervical cancer is usually treated with external beam radiotherapy followed by brachytherapy (BT). However, if response or tumour topography is unfavourable it may be difficult to reach a sufficient BT dose. The purpose of this study was to explore whether an applicator guided stereotactic IMRT boost could be combined with brachytherapy to improve dose volume parameters. Material and methods. Dose plans of 6 patients with HR CTV volumes of 31-100cc at the time of BT were analysed. MRI was performed with a combined intracavitary (IC)-interstitial (IS) ring applicator in situ. A radiotherapy schedule consisting of 45Gy (1.8Gyx25) IMRT followed by boost of 28Gy (7Gyx4fx) was modelled. Four different boost techniques were evaluated: IC-BT, IC/IS-BT, IC-BT+IMRT and IMRT. Dose plans were optimised for maximal tumour dose (D90) and coverage (V85Gy) while respecting DVH constraints in organs at risk: D2cc <75Gy in rectum and sigmoid and <90Gy in bladder (EQD2). In combined BT+IMRT dose plans, the IMRT plan was optimised on top of the BT dose distribution. Volumes irradiated to more than 60 Gy EQD2 (V60Gy) were evaluated. Results. Median dose coverage in IC plans was 74% [66-93%]. By using IC/IS or IC-BT+IMRT boost, the median coverage was improved to 95% [78-99%], and to 96% [69-99%] respectively. For IMRT alone, a median coverage of 98% [90-100%] was achieved, but V60Gy volumes were significantly increased by a median factor of 2.0 [1.4-2.3] as compared to IC/IS. It depended on the individual tumour topography whether IC/IS-BT or IC-BT+IMRT boost was the most favourable technique. Conclusion. It is technically possible to create dose plans that combine image guided BT and IMRT. In this study the dose coverage could be significantly increased by adding IS-BT or IMRT boost to the intracavitary dose. Using IMRT alone for boost cannot be advocated since this results in a significant increase of the volume irradiated to 60Gy

Implementation of three-dimensional planning in brachytherapy of high dose rate for gynecology therapies; Implementacao de planejamento tridimensional em braquiterapia de alta taxa de dose para tratamentos ginecologicos

Energy Technology Data Exchange (ETDEWEB)

Sales, Camila Pessoa de

2015-09-01

This work aims to implement the three-dimensional (3D) planning for gynecological brachytherapy treatments. For this purpose, tests of acceptance and commissioning of brachytherapy equipment were performed to establish a quality and periodic assurance program. For this purpose, an important step was searching for a material to be used as a dummy source, since the applicators do not have any specific dummy. In addition, the validation of the use of applicators library was made for reconstruction in computed tomography (CT) and magnetic resonance imaging (MRI). In order to validate 3D planning, comparison of doses in dose assessment points used in bidimensional (2D) plans have been performed with volumetric doses to adjacent organs to the tumor. Finally, a protocol was established for 3D brachytherapy planning alternately using magnetic resonance image (MRI) and CT images, making evaluation of the dose in the tumor through the recording of MR and CT images. It was not possible to find a suitable material that could be used as dummy in MRI. However, the acquisition of the license's library for the applicators made possible the 3D planning based on MRI. No correlation was found between volumetric and specific doses analyzed, showing the importance of the implementation of 3D planning. The average ratio between D{sub 2cc} and ICRU{sub Bladder} dose was 1,74, 22% higher than the ratio found by others authors. For the rectum, D{sub 2cc} was less than dose point for 60% of fractions; the average difference was 12,5%. The average ratio between D{sub 2cc} and point dose rectum, 0,85, is equivalent to the value showed by Kim et al, 0,91. The D{sub 2cc} for sigmoid was 69% higher than point dose used, unless it was not possible compare this value, since the sigmoid point used in the 2D procedures is not used in others institutes. Relative dose in 2 cc of sigmoid was 57% of the prescription dose, the same value was found by in literature. This work enabled the

Is there any advantage of CT based 3-dimensional conformal planning over conventional orthogonal x-ray based planning in HDR brachytherapy in breast cancer

International Nuclear Information System (INIS)

Biswal, B.M.; Idris, N.R.; Zakaria, A.B.; Khairul, N.

2003-01-01

The conventional brachytherapy dose calculation is based on a particular brachytherapy rule or individual dosimetry based on the reconstruction of the sources from the orthogonal films. In the recent years many centers are using CT based 3D conformal brachytherapy in order to improve the dosimetric outcome of a given plan. Here we would like to present our experience on the use of both techniques to deliver HDR interstitial brachytherapy as boost in early breast cancer. From January 2001 to January 2003, we treated 4 breast cancer patients using conventional orthogonal x-rays and CT scan in 3 cases for the treatment plan. All patients received an external beam radiotherapy dose of 46 Gy in 23 fractions over 4.5 weeks to the whole breast using 6 MV photon beam. Subsequently the primary lesion was supplimented with HDR brachytherapy to a dose of 2.5 Gy BID for 3 consecutive days using a (192)Ir microSelectronHDR. The dose prescription was individualized to encompass the tumor volume with a 10 mm margin. The differences of the dosimetric outcome were compared. All patients completed above schedule of radiotherapy. The primary was implanted with single plane in 3 patients and multiplane implant in 4 patients. Orthogonal x-ray based localization was performed in 4 patients and CT scan based localization in 3 cases. Three patients were implanted single plane and 4 patients with multiplane implants with a median catheter number of 9 (range 6-14). The 3D conformal dose optimization was performed using Nucletron planning system (Plato). The mean 100% and 150% isodose volume was 67.3 cm 3 and 31.25cm 3 respectively. The identification of primary tumor volume, organ at risk, and identification of afterloading catheters were superior in CT based plan than conventional planning. CT scan based 3D conformal brachytherapy planning give better identification of tumor volume and its curvature, decrease the time to identify the sources and evaluate the radiation dose to organs at

Variability of Marker-Based Rectal Dose Evaluation in HDR Cervical Brachytherapy

International Nuclear Information System (INIS)

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.

Magnetic Resonance Imaging-Guided Intracavitary Brachytherapy for Cancer of the Cervix

International Nuclear Information System (INIS)

Zwahlen, Daniel; Jezioranski, John; Chan, Philip; Haider, Masoom A.; Cho, Young-Bin; Yeung, Ivan; Levin, Wilfred; Manchul, Lee; Fyles, Anthony; Milosevic, Michael

2009-01-01

Purpose: To determine the feasibility and benefits of optimized magnetic resonance imaging (MRI)-guided brachytherapy (BT) for cancer of the cervix. Methods and Materials: A total of 20 patients with International Federation of Gynecology and Obstetrics Stage IB-IV cervical cancer had an MRI-compatible intrauterine BT applicator inserted after external beam radiotherapy. MRI scans were acquired, and the gross tumor volume at diagnosis and at BT, the high-risk (HR) and intermediate-risk clinical target volume (CTV), and rectal, sigmoid, and bladder walls were delineated. Pulsed-dose-rate BT was planned and delivered in a conventional manner. Optimized MRI-based plans were developed and compared with the conventional plans. Results: The HR CTV and intermediate-risk CTV were adequately treated (the percentage of volume treated to ≥100% of the intended dose was >95%) in 70% and 85% of the patients with the conventional plans, respectively, and in 75% and 95% of the patients with the optimized plans, respectively. The minimal dose to the contiguous 2 cm 3 of the rectal, sigmoid, and bladder wall volume was 16 ± 6.2, 25 ± 8.7, and 31 ± 9.2 Gy, respectively. With MRI-guided BT optimization, it was possible to maintain coverage of the HR-CTV and reduce the dose to the normal tissues, especially in patients with small tumors at BT. In these patients, the HR percentage of volume treated to ≥100% of the intended dose approached 100% in all cases, and the minimal dose to the contiguous 2-cm 3 of the rectum, sigmoid, and bladder was 12-32% less than with conventional BT planning. Conclusion: MRI-based BT for cervical cancer has the potential to optimize primary tumor dosimetry and reduce the dose to critical normal tissues, particularly in patients with small tumors.

Role of TPS in 125I brachytherapy for orbital tumors

International Nuclear Information System (INIS)

Ren Ling; Dai Haojie; Li Quan

2012-01-01

Objective: To investigate the role of TPS in 125 I brachytherapy for orbital tumors. Methods: Sixty-six patients with orbital tumor treated with 125 I seeds from 2005 to 2009 were retrospectively analyzed. Forty-three patients were treated using TPS guided brachytherapy and the prescribed dose was 140 Gy. Other 23 patients were treated without TPS but simply implanted with 125 I seeds at 1 cm intervals in parallel with each other intraoperatively. CT and TPS quality verification were performed postoperatively in all patients. Also, CT and (or) MRI examination were performed at 3, 6, 12 and 24 months after brachytherapy for follow-up. χ 2 test and Kaplan-Meier survival analysis with log-rank significance test were used with SPSS 17.0. Results: A total of 1070 125 I seeds were implanted in 66 cases, on average, (16.2 ± 7.3) seeds for each patient. The satisfaction rates of postoperative quality verification in patients with and without TPS pre-plans were 79.07% (34/43) and 43.48% (10/23) respectively (χ 2 =8.542, P=0.003). Ten patients were lost in follow-up. Local recurrence rates in patients with favorable postoperative quality verification were 0 (0/37) in 3 months, 6.25% (2/32) in 6 months, 13.64% (3/22) in 12 months and 3/9 in 24 months respectively, which were significantly different from those (5.26% (1/19), 16.67% (3/18), 30.77% (4/13), 6/6) in the patients with inferior postoperative quality verification (χ 2 =9.017, P=0.0003). Conclusions: TPS plays an important role in 125 I brachytherapy for orbital tumors. Also, postoperative quality verification by TPS may help predict the local recurrence after brachytherapy. (authors)

The American Brachytherapy Society recommendations for low-dose-rate brachytherapy for carcinoma of the cervix

International Nuclear Information System (INIS)

Nag, Subir; Chao, Clifford; Erickson, Beth; Fowler, Jeffery; Gupta, Nilendu; Martinez, Alvaro; Thomadsen, Bruce

2002-01-01

Purpose: This report presents guidelines for using low-dose-rate (LDR) brachytherapy in the management of patients with cervical cancer. Methods: Members of the American Brachytherapy Society (ABS) with expertise in LDR brachytherapy for cervical cancer performed a literature review, supplemented by their clinical experience, to formulate guidelines for LDR brachytherapy of cervical cancer. Results: The ABS strongly recommends that radiation treatment for cervical carcinoma (with or without chemotherapy) should include brachytherapy as a component. Precise applicator placement is essential for improved local control and reduced morbidity. The outcome of brachytherapy depends, in part, on the skill of the brachytherapist. Doses given by external beam radiotherapy and brachytherapy depend upon the initial volume of disease, the ability to displace the bladder and rectum, the degree of tumor regression during pelvic irradiation, and institutional practice. The ABS recognizes that intracavitary brachytherapy is the standard technique for brachytherapy for cervical carcinoma. Interstitial brachytherapy should be considered for patients with disease that cannot be optimally encompassed by intracavitary brachytherapy. The ABS recommends completion of treatment within 8 weeks, when possible. Prolonging total treatment duration can adversely affect local control and survival. Recommendations are made for definitive and postoperative therapy after hysterectomy. Although recognizing that many efficacious LDR dose schedules exist, the ABS presents suggested dose and fractionation schemes for combining external beam radiotherapy with LDR brachytherapy for each stage of disease. The dose prescription point (point A) is defined for intracavitary insertions. Dose rates of 0.50 to 0.65 Gy/h are suggested for intracavitary brachytherapy. Dose rates of 0.50 to 0.70 Gy/h to the periphery of the implant are suggested for interstitial implant. Use of differential source activity or

Prostate cancer brachytherapy

International Nuclear Information System (INIS)

Abreu, Carlos Eduardo Vita; Silva, Joao L. F.; Srougi, Miguel; Nesrallah, Adriano

1999-01-01

The transperineal brachytherapy with 125 I/Pd 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

Comparison of Real-Time Intraoperative Ultrasound-Based Dosimetry With Postoperative Computed Tomography-Based Dosimetry for Prostate Brachytherapy

International Nuclear Information System (INIS)

Nag, Subir; Shi Peipei; Liu Bingren; Gupta, Nilendu; Bahnson, Robert R.; Wang, Jian Z.

2008-01-01

Purpose: To evaluate whether real-time intraoperative ultrasound (US)-based dosimetry can replace conventional postoperative computed tomography (CT)-based dosimetry in prostate brachytherapy. Methods and Materials: Between December 2001 and November 2002, 82 patients underwent 103 Pd prostate brachytherapy. An interplant treatment planning system was used for real-time intraoperative transrectal US-guided treatment planning. The dose distribution was updated according to the estimated seed position to obtain the dose-volume histograms. Postoperative CT-based dosimetry was performed a few hours later using the Theraplan-Plus treatment planning system. The dosimetric parameters obtained from the two imaging modalities were compared. Results: The results of this study revealed correlations between the US- and CT-based dosimetry. However, large variations were found in the implant-quality parameters of the two modalities, including the doses covering 100%, 90%, and 80% of the prostate volume and prostate volumes covered by 100%, 150%, and 200% of the prescription dose. The mean relative difference was 38% and 16% for doses covering 100% and 90% of the prostate volume and 10% and 21% for prostate volumes covered by 100% and 150% of the prescription dose, respectively. The CT-based volume covered by 200% of the prescription dose was about 30% greater than the US-based one. Compared with CT-based dosimetry, US-based dosimetry significantly underestimated the dose to normal organs, especially for the rectum. The average US-based maximal dose and volume covered by 100% of the prescription dose for the rectum was 72 Gy and 0.01 cm 3 , respectively, much lower than the 159 Gy and 0.65 cm 3 obtained using CT-based dosimetry. Conclusion: Although dosimetry using intraoperative US-based planning provides preliminary real-time information, it does not accurately reflect the postoperative CT-based dosimetry. Until studies have determined whether US-based dosimetry or

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

International Nuclear Information System (INIS)

Poetter, Richard; Haie-Meder, Christine; Limbergen, Erik van; Barillot, Isabelle; Brabandere, Marisol De; Dimopoulos, Johannes; Dumas, Isabelle; Erickson, Beth; Lang, Stefan; Nulens, An; Petrow, Peter; Rownd, Jason; Kirisits, Christian

2006-01-01

. Recommendations from Gynaecological (GYN) GEC ESTRO Working Group (I): concepts and terms in 3D image-based 3D treatment planning in cervix cancer brachytherapy with emphasis on MRI assessment of GTV and CTV. Radiother Oncol 2005;74:235-245]). It is expected that the therapeutic ratio including target coverage and sparing of organs at risk can be significantly improved, if radiation dose is prescribed to a 3D image-based CTV taking into account dose volume constraints for OAR. However, prospective use of these recommendations in the clinical context is warranted, to further explore and develop the potential of 3D image-based cervix cancer brachytherapy

SU-F-I-19: MRI Positive Contrast Visualization of Prostate Brachytherapy Seeds Using An Integrated Laplacian-Based Phase Processing

Energy Technology Data Exchange (ETDEWEB)

Soliman, A; Safigholi, H [Sunnybrook Research Institute, Toronto, ON (Canada); Sunnybrook Health Sciences Center, Toronto, ON (Canada); Nosrati, R [Sunnybrook Health Sciences Center, Toronto, ON (Canada); Ryerson University, Toronto, ON (Canada); Owrangi, A; Morton, G [Sunnybrook Health Sciences Center, Toronto, ON (Canada); University of Toronto, Toronto, ON (Canada); Song, W [Sunnybrook Research Institute, Toronto, ON (Canada); Sunnybrook Health Sciences Center, Toronto, ON (Canada); Ryerson University, Toronto, ON (Canada); University of Toronto, Toronto, ON (Canada)

2016-06-15

Purpose: To propose a new method that provides a positive contrast visualization of the prostate brachytherapy seeds using the phase information from MR images. Additionally, the feasibility of using the processed phase information to distinguish seeds from calcifications is explored. Methods: A gel phantom was constructed using 2% agar dissolved in 1 L of distilled water. Contrast agents were added to adjust the relaxation times. Four iodine-125 (Eckert & Ziegler SML86999) dummy seeds were placed at different orientations with respect to the main magnetic field (B0). Calcifications were obtained from a sheep femur cortical bone due to its close similarity to human bone tissue composition. Five samples of calcifications were shaped into different dimensions with lengths ranging between 1.2 – 6.1 mm.MR imaging was performed on a 3T Philips Achieva using an 8-channel head coil. Eight images were acquired at eight echo-times using a multi-gradient echo sequence. Spatial resolution was 0.7 × 0.7 × 2 mm, TR/TE/dTE = 20.0/2.3/2.3 ms and BW = 541 Hz/pixel. Complex images were acquired and fed into a two-step processing pipeline: the first includes phase unwrapping and background phase removal using Laplacian operator (Wei et al. 2013). The second step applies a specific phase mask on the resulting tissue phase from the first step to provide the desired positive contrast of the seeds and to, potentially, differentiate them from the calcifications. Results: The phase-processing was performed in less than 30 seconds. The proposed method has successfully resulted in a positive contrast of the brachytherapy seeds. Additionally, the final processed phase image showed difference between the appearance of seeds and calcifications. However, the shape of the seeds was slightly distorted compared to the original dimensions. Conclusion: It is feasible to provide a positive contrast of the seeds from MR images using Laplacian operator-based phase processing.

MO-B-BRC-02: Ultrasound Based Prostate HDR

Energy Technology Data Exchange (ETDEWEB)

Chang, Z. [Duke University Medical Center (United States)

2016-06-15

Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.

MO-B-BRC-02: Ultrasound Based Prostate HDR

International Nuclear Information System (INIS)

Chang, Z.

2016-01-01

Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions

MO-B-BRC-03: CT-Based Prostate HDR

International Nuclear Information System (INIS)

Zoberi, J.

2016-01-01

Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions

MO-B-BRC-03: CT-Based Prostate HDR

Energy Technology Data Exchange (ETDEWEB)

Zoberi, J. [Washington University School of Medicine (United States)

2016-06-15

Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.

WE-AB-BRA-12: Post-Implant Dosimetry in Prostate Brachytherapy by X-Ray and MRI Fusion

Energy Technology Data Exchange (ETDEWEB)

Park, S; Song, D; Lee, J [Johns Hopkins University, Baltimore, MD (United States); Le, Y [Indiana University, Indianapolis, IN (United States)

2016-06-15

Purpose: For post-implant dosimetric assessment after prostate brachytherapy, CT-MR fusion approach has been advocated due to the superior accuracy on both seeds localization and soft tissue delineation. However, CT deposits additional radiation to the patient, and seed identification in CT requires manual review and correction. In this study, we propose an accurate, low-dose, and cost-effective post-implant dosimetry approach based on X-ray and MRI. Methods: Implanted seeds are reconstructed using only three X-ray fluoroscopy images by solving a combinatorial optimization problem. The reconstructed seeds are then registered to MR images using an intensity-based points-to-volume registration. MR images are first pre-processed by geometric and Gaussian filtering, yielding smooth candidate seed-only images. To accommodate potential soft tissue deformation, our registration is performed in two steps, an initial affine followed by local deformable registrations. An evolutionary optimizer in conjunction with a points-to-volume similarity metric is used for the affine registration. Local prostate deformation and seed migration are then adjusted by the deformable registration step with external and internal force constraints. Results: We tested our algorithm on twenty patient data sets. For quantitative evaluation, we obtained ground truth seed positions by fusing the post-implant CT-MR images. Seeds were semi-automatically extracted from CT and manually corrected and then registered to the MR images. Target registration error (TRE) was computed by measuring the Euclidean distances from the ground truth to the closest registered X-ray seeds. The overall TREs (mean±standard deviation in mm) are 1.6±1.1 (affine) and 1.3±0.8 (affine+deformable). The overall computation takes less than 1 minute. Conclusion: It has been reported that the CT-based seed localization error is ∼1.6mm and the seed localization uncertainty of 2mm results in less than 5% deviation of prostate D

WE-AB-BRA-12: Post-Implant Dosimetry in Prostate Brachytherapy by X-Ray and MRI Fusion

International Nuclear Information System (INIS)

Park, S; Song, D; Lee, J; Le, Y

2016-01-01

Purpose: For post-implant dosimetric assessment after prostate brachytherapy, CT-MR fusion approach has been advocated due to the superior accuracy on both seeds localization and soft tissue delineation. However, CT deposits additional radiation to the patient, and seed identification in CT requires manual review and correction. In this study, we propose an accurate, low-dose, and cost-effective post-implant dosimetry approach based on X-ray and MRI. Methods: Implanted seeds are reconstructed using only three X-ray fluoroscopy images by solving a combinatorial optimization problem. The reconstructed seeds are then registered to MR images using an intensity-based points-to-volume registration. MR images are first pre-processed by geometric and Gaussian filtering, yielding smooth candidate seed-only images. To accommodate potential soft tissue deformation, our registration is performed in two steps, an initial affine followed by local deformable registrations. An evolutionary optimizer in conjunction with a points-to-volume similarity metric is used for the affine registration. Local prostate deformation and seed migration are then adjusted by the deformable registration step with external and internal force constraints. Results: We tested our algorithm on twenty patient data sets. For quantitative evaluation, we obtained ground truth seed positions by fusing the post-implant CT-MR images. Seeds were semi-automatically extracted from CT and manually corrected and then registered to the MR images. Target registration error (TRE) was computed by measuring the Euclidean distances from the ground truth to the closest registered X-ray seeds. The overall TREs (mean±standard deviation in mm) are 1.6±1.1 (affine) and 1.3±0.8 (affine+deformable). The overall computation takes less than 1 minute. Conclusion: It has been reported that the CT-based seed localization error is ∼1.6mm and the seed localization uncertainty of 2mm results in less than 5% deviation of prostate D

MR-based source localization for MR-guided HDR brachytherapy

Science.gov (United States)

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

2018-04-01

For the purpose of MR-guided high-dose-rate (HDR) brachytherapy, a method for real-time localization of an HDR brachytherapy source was developed, which requires high spatial and temporal resolutions. MR-based localization of an HDR source serves two main aims. First, it enables real-time treatment verification by determination of the HDR source positions during treatment. Second, when using a dummy source, MR-based source localization provides an automatic detection of the source dwell positions after catheter insertion, allowing elimination of the catheter reconstruction procedure. Localization of the HDR source was conducted by simulation of the MR artifacts, followed by a phase correlation localization algorithm applied to the MR images and the simulated images, to determine the position of the HDR source in the MR images. To increase the temporal resolution of the MR acquisition, the spatial resolution was decreased, and a subpixel localization operation was introduced. Furthermore, parallel imaging (sensitivity encoding) was applied to further decrease the MR scan time. The localization method was validated by a comparison with CT, and the accuracy and precision were investigated. The results demonstrated that the described method could be used to determine the HDR source position with a high accuracy (0.4–0.6 mm) and a high precision (⩽0.1 mm), at high temporal resolutions (0.15–1.2 s per slice). This would enable real-time treatment verification as well as an automatic detection of the source dwell positions.

University Cooperation Platform (UCP) between Christian-Albrechts-University Kiel (Germany) and Chiang Mai University (Thailand): implementation of image-guided gynecological brachytherapy.

Science.gov (United States)

Galalae, Razvan; Tharavichitkul, Ekkasit; Wanwilairat, Somsak; Chitapanarux, Imjai; Kimmig, Bernhard; Dunst, Jürgen; Lorvidhaya, Vicharn

2015-02-01

Starting in 1999, the University Cooperation Platform (UCP) implemented an exchange program of researchers and clinicians/physicists between the Christian-Albrechts-University Kiel in Germany and Chiang Mai University in Thailand, to initiate a sustainable base for long-term development of image-guided brachytherapy and in general for high-technology radiotherapy in Chiang Mai. A series of UCP protocols, based constructively on each other, were performed and evaluated at intermediate term follow-up. The first protocol, addressing computed tomography (CT)-optimized brachytherapy for advanced cervical cancer (n = 17), showed a significant reduction of D2cc for the bladder and sigmoid (p 80 Gy for bladder in only 17.2% versus 62.1% in conventional planning, and in rectum EQD2 > 75 Gy in 44.8% versus 79.3%, respectively. In conclusion, analyses revealed excellent results for the high-dose-rate IGBT in patients with advanced gynecological cancer both by using CT and MRI, and/or the combination with WP-IMRT. They also define MRI as gold standard for soft tissue assessment and to determine more accurately HR-CTV. The use of TAUS-guidance adds quality aspects to the "classical" conventional X-ray based planning, especially in terms of real-time measures and adequate soft tissue information, and may lower significantly the dose in OARs. The review of all UCP-results reconfirms the importance of the established program that will continue to operate with subsequent projects.

Bowel morbidity following radiochemotherapy and image-guided adaptive brachytherapy for cervical cancer: Physician- and patient reported outcome from the EMBRACE study

DEFF Research Database (Denmark)

Jensen, Nina Boje Kibsgaard; Pötter, Richard; Kirchheiner, Kathrin

2018-01-01

BACKGROUND/PURPOSE: This study describes late bowel morbidity prospectively assessed in the multi-institutional EMBRACE study on MRI-guided adaptive brachytherapy in locally advanced cervical cancer (LACC). MATERIALS/METHODS: A total of 1176 patients were analyzed. Physician reported morbidity (C...

Total reference air kerma can accurately predict isodose surface volumes in cervix cancer brachytherapy. A multicenter study

DEFF Research Database (Denmark)

Nkiwane, Karen S; Andersen, Else; Champoudry, Jerome

2017-01-01

PURPOSE: To demonstrate that V60 Gy, V75 Gy, and V85 Gy isodose surface volumes can be accurately estimated from total reference air kerma (TRAK) in cervix cancer MRI-guided brachytherapy (BT). METHODS AND MATERIALS: 60 Gy, 75 Gy, and 85 Gy isodose surface volumes levels were obtained from treatm...

Neutrophilia in locally advanced cervical cancer: A novel biomarker for image-guided adaptive brachytherapy?

Science.gov (United States)

Escande, Alexandre; Haie-Meder, Christine; Maroun, Pierre; Gouy, Sébastien; Mazeron, Renaud; Leroy, Thomas; Bentivegna, Enrica; Morice, Philippe; Deutsch, Eric; Chargari, Cyrus

2016-01-01

Objective To study the prognostic value of leucocyte disorders in a prospective cohort of cervical cancer patients receiving definitive chemoradiation plus image—guided adaptive brachytherapy (IGABT). Results 113 patients were identified. All patients received a pelvic irradiation concomitant with chemotherapy, extended to the para-aortic area in 13 patients with IVB disease. Neutrophilia and leukocytosis were significant univariate prognostic factors for poorer local failure-free survival (p = 0.000 and p = 0.002, respectively), associated with tumor size, high-risk clinical target volume (HR-CTV) and anemia. No effect was shown for distant metastases but leukocytosis and neutrophila were both poor prognostic factors for in-field relapses (p = 0.003 and p 7,500/μl (p = 0.018) were independent factors for poorer survival without local failure, with hazard ratio (HR) of 3.1. Materials and methods We examined patients treated in our Institution between April 2009 and July 2015 by concurrent chemoradiation (45 Gy in 25 fractions +/− lymph node boosts) followed by a magnetic resonance imaging (MRI)-guided adaptive pulse-dose rate brachytherapy (15 Gy to the intermediate-risk clinical target volume). The prognostic value of pretreatment leucocyte disorders was examined. Leukocytosis and neutrophilia were defined as a leukocyte count or a neutrophils count exceeding 10,000 and 7,500/μl, respectively. Conclusions Neutrophilia is a significant prognostic factor for local relapse in locally advanced cervical cancer treated with MRI-based IGABT. This biomarker could help identifying patients with higher risk of local relapse and requiring dose escalation. PMID:27713124

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...

Quality assurance in MR image guided adaptive brachytherapy for cervical cancer: Final results of the EMBRACE study dummy run

DEFF Research Database (Denmark)

Kirisits, Christian; Federico, Mario; Nkiwane, Karen

2015-01-01

and BT. Centers with experience in IGABT (>30 cases) had better performance as compared to centers with limited experience. CONCLUSION: The comprehensive dummy run designed for the EMBRACE trial has been a feasible tool for QA in IGABT of cervix cancer. It should be considered for future IGABT trials...... aspects of image guided adaptive brachytherapy (IGABT). METHODS AND MATERIALS: EMBRACE is a prospective multicenter trial aiming to assess the impact of (MRI)-based IGABT in locally advanced cervical cancer. An EMBRACE dummy run was designed to identify sources and magnitude of uncertainties and errors...

CT-image-based conformal brachytherapy of breast cancer. The significance of semi-3-D and 3-D treatment planning.

Science.gov (United States)

Polgár, C; Major, T; Somogyi, A; Takácsi-Nagy, Z; Mangel, L C; Forrai, G; Sulyok, Z; Fodor, J; Németh, G

2000-03-01

To compare the conventional 2-D, the simulator-guided semi-3-D and the recently developed CT-guided 3-D brachytherapy treatment planning in the interstitial radiotherapy of breast cancer. In 103 patients with T1-2, N0-1 breast cancer the tumor bed was clipped during breast conserving surgery. Fifty-two of them received boost brachytherapy after 46 to 50 Gy teletherapy and 51 patients were treated with brachytherapy alone via flexible implant tubes. Single, double and triple plane implant was used in 6, 89 and 8 cases, respectively. The dose of boost brachytherapy and sole brachytherapy prescribed to dose reference points was 3 times 4.75 Gy and 7 times 5.2 Gy, respectively. The positions of dose reference points varied according to the level (2-D, semi-3-D and 3-D) of treatment planning performed. The treatment planning was based on the 3-D reconstruction of the surgical clips, implant tubes and skin points. In all cases the implantations were planned with a semi-3-D technique aided by simulator. In 10 cases a recently developed CT-guided 3-D planning system was used. The semi-3-D and 3-D treatment plans were compared to hypothetical 2-D plans using dose-volume histograms and dose non-uniformity ratios. The values of mean central dose, mean skin dose, minimal clip dose, proportion of underdosaged clips and mean target surface dose were evaluated. The accuracy of tumor bed localization and the conformity of planning target volume and treated volume were also analyzed in each technique. With the help of conformal semi-3-D and 3-D brachytherapy planning we could define reference dose points, active source positions and dwell times individually. This technique decreased the mean skin dose with 22.2% and reduced the possibility of geographical miss. We could achieve the best conformity between the planning target volume and the treated volume with the CT-image based 3-D treatment planning, at the cost of worse dose homogeneity. The mean treated volume was reduced by 25

Should helical tomotherapy replace brachytherapy for cervical cancer? Case report.

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Hsieh, Chen-Hsi; Wei, Ming-Chow; Hsu, Yao-Peng; Chong, Ngot-Swan; Chen, Yu-Jen; Hsiao, Sheng-Mou; Hsieh, Yen-Ping; Wang, Li-Ying; Shueng, Pei-Wei

2010-11-23

Stereotactic body radiation therapy (SBRT) administered via a helical tomotherapy (HT) system is an effective modality for treating lung cancer and metastatic liver tumors. Whether SBRT delivered via HT is a feasible alternative to brachytherapy in treatment of locally advanced cervical cancer in patients with unusual anatomic configurations of the uterus has never been studied. A 46-year-old woman presented with an 8-month history of abnormal vaginal bleeding. Biopsy revealed squamous cell carcinoma of the cervix. Magnetic resonance imaging (MRI) showed a cervical tumor with direct invasion of the right parametrium, bilateral hydronephrosis, and multiple uterine myomas. International Federation of Gynecology and Obstetrics (FIGO) stage IIIB cervical cancer was diagnosed. Concurrent chemoradiation therapy (CCRT) followed by SBRT delivered via HT was administered instead of brachytherapy because of the presence of multiple uterine myomas with bleeding tendency. Total abdominal hysterectomy was performed after 6 weeks of treatment because of the presence of multiple uterine myomas. Neither pelvic MRI nor results of histopathologic examination at X-month follow-up showed evidence of tumor recurrence. Only grade 1 nausea and vomiting during treatment were noted. Lower gastrointestinal bleeding was noted at 14-month follow-up. No fistula formation and no evidence of haematological, gastrointestinal or genitourinary toxicities were noted on the most recent follow-up. CCRT followed by SBRT appears to be an effective and safe modality for treatment of cervical cancer. Larger-scale studies are warranted.

Should helical tomotherapy replace brachytherapy for cervical cancer? Case report

Directory of Open Access Journals (Sweden)

Chen Yu-Jen

2010-11-01

Full Text Available Abstract Background Stereotactic body radiation therapy (SBRT administered via a helical tomotherapy (HT system is an effective modality for treating lung cancer and metastatic liver tumors. Whether SBRT delivered via HT is a feasible alternative to brachytherapy in treatment of locally advanced cervical cancer in patients with unusual anatomic configurations of the uterus has never been studied. Case Presentation A 46-year-old woman presented with an 8-month history of abnormal vaginal bleeding. Biopsy revealed squamous cell carcinoma of the cervix. Magnetic resonance imaging (MRI showed a cervical tumor with direct invasion of the right parametrium, bilateral hydronephrosis, and multiple uterine myomas. International Federation of Gynecology and Obstetrics (FIGO stage IIIB cervical cancer was diagnosed. Concurrent chemoradiation therapy (CCRT followed by SBRT delivered via HT was administered instead of brachytherapy because of the presence of multiple uterine myomas with bleeding tendency. Total abdominal hysterectomy was performed after 6 weeks of treatment because of the presence of multiple uterine myomas. Neither pelvic MRI nor results of histopathologic examination at X-month follow-up showed evidence of tumor recurrence. Only grade 1 nausea and vomiting during treatment were noted. Lower gastrointestinal bleeding was noted at 14-month follow-up. No fistula formation and no evidence of haematological, gastrointestinal or genitourinary toxicities were noted on the most recent follow-up. Conclusions CCRT followed by SBRT appears to be an effective and safe modality for treatment of cervical cancer. Larger-scale studies are warranted.

Should helical tomotherapy replace brachytherapy for cervical cancer? Case report

International Nuclear Information System (INIS)

Hsieh, Chen-Hsi; Wei, Ming-Chow; Hsu, Yao-Peng; Chong, Ngot-Swan; Chen, Yu-Jen; Hsiao, Sheng-Mou; Hsieh, Yen-Ping; Wang, Li-Ying; Shueng, Pei-Wei

2010-01-01

Stereotactic body radiation therapy (SBRT) administered via a helical tomotherapy (HT) system is an effective modality for treating lung cancer and metastatic liver tumors. Whether SBRT delivered via HT is a feasible alternative to brachytherapy in treatment of locally advanced cervical cancer in patients with unusual anatomic configurations of the uterus has never been studied. A 46-year-old woman presented with an 8-month history of abnormal vaginal bleeding. Biopsy revealed squamous cell carcinoma of the cervix. Magnetic resonance imaging (MRI) showed a cervical tumor with direct invasion of the right parametrium, bilateral hydronephrosis, and multiple uterine myomas. International Federation of Gynecology and Obstetrics (FIGO) stage IIIB cervical cancer was diagnosed. Concurrent chemoradiation therapy (CCRT) followed by SBRT delivered via HT was administered instead of brachytherapy because of the presence of multiple uterine myomas with bleeding tendency. Total abdominal hysterectomy was performed after 6 weeks of treatment because of the presence of multiple uterine myomas. Neither pelvic MRI nor results of histopathologic examination at X-month follow-up showed evidence of tumor recurrence. Only grade 1 nausea and vomiting during treatment were noted. Lower gastrointestinal bleeding was noted at 14-month follow-up. No fistula formation and no evidence of haematological, gastrointestinal or genitourinary toxicities were noted on the most recent follow-up. CCRT followed by SBRT appears to be an effective and safe modality for treatment of cervical cancer. Larger-scale studies are warranted

Quality assurance in MR image guided adaptive brachytherapy for cervical cancer: Final results of the EMBRACE study dummy run.

Science.gov (United States)

Kirisits, Christian; Federico, Mario; Nkiwane, Karen; Fidarova, Elena; Jürgenliemk-Schulz, Ina; de Leeuw, Astrid; Lindegaard, Jacob; Pötter, Richard; Tanderup, Kari

2015-12-01

Upfront quality assurance (QA) is considered essential when starting a multicenter clinical trial in radiotherapy. Despite the long experience gained for external beam radiotherapy (EBRT) trials, there are only limited audit QA methods for brachytherapy (BT) and none include the specific aspects of image guided adaptive brachytherapy (IGABT). EMBRACE is a prospective multicenter trial aiming to assess the impact of (MRI)-based IGABT in locally advanced cervical cancer. An EMBRACE dummy run was designed to identify sources and magnitude of uncertainties and errors considered important for the evaluation of clinical, and dosimetric parameters and their relation to outcome. Contouring, treatment planning and dose reporting was evaluated and scored with a categorical scale of 1-10. Active feedback to centers was provided to improve protocol compliance and reporting. A second dummy run was required in case of major deviations (score 30 cases) had better performance as compared to centers with limited experience. The comprehensive dummy run designed for the EMBRACE trial has been a feasible tool for QA in IGABT of cervix cancer. It should be considered for future IGABT trials and could serve as the basis for continuous quality checks for brachytherapy centers. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Use of CT or MR dosimetry in high dose rate (HDR) brachytherapy for prostate cancer

International Nuclear Information System (INIS)

Liu, C.; Das, R.; See, A.; Duchesne, G.M.; Van Dyk, S.; Tai, K.H.

2003-01-01

Brachytherapy (BT) has, in recent years, become a well-utilised treatment option for prostate cancer. Tumour control probability relies on accurate dosimetry, which in turn relies on the accurate definition of the prostate gland. In external beam radiotherapy and BT, MRI has been shown to be a superior imaging modality when delineating the prostate gland especially at the apex. To date, data on MRI planning in prostate BT has focussed mainly on permanent interstitial implants. No data currently exists comparing MRI vs CT planning in HDR BT and its subsequent impact on prostate dosimetry. To determine the effects of MRI vs CT in HDR BT with respect to prostatic volumes and normal tissue doses, with the evaluations made using dose-volume histograms (DVH). Dosimetry parameters derived using CT and MRI (T2 weighted) scans of 11 patients who had received TRUS guided implants for HDR BT, were compared using the PlatoTM computer planning system. Treatment plans were generated on volumes marked by the same radiation oncologist for each patient. Comparison was made of the treatment plans (dosimetry) between: 1. CT generated plans; 2. CT generated plans assessed using MRI marked volumes and 3. MRI generated plans. We confirm the previously reported results that CT scans can overestimate prostatic volumes compared with MRI. Variations were noted in CT and MRI based plans that may allow improved sparing of the rectum and urethra when using MRI planning. The main disadvantages of using MRI scans are access to facilities as well as identifying a dummy source to adequately define the tips of our catheters. It is feasible to utilise MRI scans for HDR BT planning. The clearer definition of anatomical structures has added advantages when contouring the prostate

Reproducibility and interoperator reliability of obtaining images and measurements of the cervix and uterus with brachytherapy treatment applicators in situ using transabdominal ultrasound.

Science.gov (United States)

van Dyk, Sylvia; Garth, Margaret; Oates, Amanda; Kondalsamy-Chennakesavan, Srinivas; Schneider, Michal; Bernshaw, David; Narayan, Kailash

2016-01-01

To validate interoperator reliability of brachytherapy radiation therapists (RTs) in obtaining an ultrasound image and measuring the cervix and uterine dimensions using transabdominal ultrasound. Patients who underwent MRI with applicators in situ after the first insertion were included in the study. Imaging was performed by three RTs (RT1, RT2, and RT3) with varying degrees of ultrasound experience. All RTs were required to obtain a longitudinal planning image depicting the applicator in the uterine canal and measure the cervix and uterus. The MRI scan, taken 1 hour after the ultrasound, was used as the reference standard against which all measurements were compared. Measurements were analyzed with intraclass correlation coefficient and Bland-Altman plots. All RTs were able to obtain a suitable longitudinal image for each patient in the study. Mean differences (SD) between MRI and ultrasound measurements obtained by RTs ranged from 3.5 (3.6) to 4.4 (4.23) mm and 0 (3.0) to 0.9 (2.5) mm on the anterior and posterior surface of the cervix, respectively. Intraclass correlation coefficient for absolute agreement between MRI and RTs was >0.9 for all posterior measurement points in the cervix and ranged from 0.41 to 0.92 on the anterior surface. Measurements were not statistically different between RTs at any measurement point. RTs with variable training attained high levels of interoperator reliability when using transabdominal ultrasound to obtain images and measurements of the uterus and cervix with brachytherapy applicators in situ. Access to training and use of a well-defined protocol assist in achieving these high levels of reliability. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

MRI findings of radiation-induced changes in the urethra and periurethral tissues after treatment for prostate cancer

International Nuclear Information System (INIS)

Marigliano, Chiara; Donati, Olivio F.; Vargas, Hebert Alberto; Akin, Oguz; Goldman, Debra A.; Eastham, James A.; Zelefsky, Michael J.; Hricak, Hedvig

2013-01-01

Purpose: To assess radiotherapy (RT)-induced changes in the urethra and periurethral tissues after treatment for prostate cancer (PCa). Methods and materials: This retrospective study included 108 men (median age, 64 years; range, 43–87 years) who received external-beam radiotherapy (EBRT) and/or brachytherapy for PCa and underwent endorectal-coil MRI of the prostate within 180 days before RT and a median of 20 months (range, 2–62 months) after RT. On all MRIs, two readers independently measured the urethral length (UL) and graded the margin definition (MD) of the urethral wall and the signal intensities (SIs) of the urethral wall and pelvic muscles on 4-point scales. Results: The mean urethral length decreased significantly from pre- to post-RT MRI (from 15.2 to 12.6 mm and from 14.4 to 12.9 mm for readers 1 and 2, respectively; both p-values <0.0001). Brachytherapy resulted in greater urethral shortening than EBRT. After RT, SI in the urethral wall increased in 57% (62/108) and 35% (38/108) of patients (readers 1 and 2, respectively). The frequency and magnitude of SI increase in pelvic muscles depended on muscle location. In the obturator internus muscle, SI increased more often after EBRT than after brachytherapy, while in the periurethral levator ani muscle SI increased more often after brachytherapy than after EBRT. Conclusion: After RT for PCa, MRI shows urethral shortening and increased SI of the urethral wall and pelvic muscles in substantial percentages of patients

MRI findings of radiation-induced changes in the urethra and periurethral tissues after treatment for prostate cancer

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Marigliano, Chiara [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Department of Radiology, University “Sapienza”, Rome (Italy); Donati, Olivio F., E-mail: olivio.donati@usz.ch [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Department of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich (Switzerland); Vargas, Hebert Alberto; Akin, Oguz; Goldman, Debra A. [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Eastham, James A. [Department of Urology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Zelefsky, Michael J. [Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Hricak, Hedvig, E-mail: hricakh@mskcc.org [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

2013-12-01

Purpose: To assess radiotherapy (RT)-induced changes in the urethra and periurethral tissues after treatment for prostate cancer (PCa). Methods and materials: This retrospective study included 108 men (median age, 64 years; range, 43–87 years) who received external-beam radiotherapy (EBRT) and/or brachytherapy for PCa and underwent endorectal-coil MRI of the prostate within 180 days before RT and a median of 20 months (range, 2–62 months) after RT. On all MRIs, two readers independently measured the urethral length (UL) and graded the margin definition (MD) of the urethral wall and the signal intensities (SIs) of the urethral wall and pelvic muscles on 4-point scales. Results: The mean urethral length decreased significantly from pre- to post-RT MRI (from 15.2 to 12.6 mm and from 14.4 to 12.9 mm for readers 1 and 2, respectively; both p-values <0.0001). Brachytherapy resulted in greater urethral shortening than EBRT. After RT, SI in the urethral wall increased in 57% (62/108) and 35% (38/108) of patients (readers 1 and 2, respectively). The frequency and magnitude of SI increase in pelvic muscles depended on muscle location. In the obturator internus muscle, SI increased more often after EBRT than after brachytherapy, while in the periurethral levator ani muscle SI increased more often after brachytherapy than after EBRT. Conclusion: After RT for PCa, MRI shows urethral shortening and increased SI of the urethral wall and pelvic muscles in substantial percentages of patients.

Three-dimensional brachytherapy optimization techniques in the treatment of patients with cervix cancer; Apport des techniques de curietherapie optimisee grace a l'imagerie tridimensionnelle dans la prise en charge des patientes atteintes d'un cancer du col uterin

Energy Technology Data Exchange (ETDEWEB)

Haie-Meder, C.; Mazeron, R.; Verezesan, O.; Monnier, L.; Vieillot, S. [Institut Gustave-Roussy, Service de Curietherapie, 94 - Villejuif (France); Dumas, I. [Institut Gustave-Roussy, Service de Physique, 94 - Villejuif (France); Lhomme, C. [Institut Gustave-Roussy, Service d' Ooncologie Gynecologique, 94 - Villejuif (France); Morice, P. [Institut Gustave-Roussy, Service de Chirurgie Oncologique, 94 - Villejuif (France); Barillot, I. [Centre Regional Universitaire de Cancerologie Henry-S.-Kaplan, Hopital Bretonneau, CHU de Tours, 37 - Tours (France); Universite Francois-Rabelais, 37 - Tours (France)

2009-10-15

Traditionally, prescription and treatment planning in intracavitary brachytherapy for cervix cancer have used either reference points (mainly points A and B) or reference isodoses (60 Gy according to ICRU recommendations) to report doses to the target volume. Doses to critical organs were reported at bladder and rectum ICRU points. This practice has been supported by a long-standing clinical experience that has yielded an acceptable therapeutic ratio. The recent development of imaging has contributed to the improvement in target and organs at risk knowledge. In 2005 and 2006, the European group of brachytherapy -European Society for therapeutic radiology and oncology (GEC-E.S.T.R.O.) recommendations publications on 3-D based image brachytherapy have defined the different volumes of interest. These recommendations have been validated with intercomparison delineation studies. With the concomitant development of remote after-loading projectors, provided with miniaturized sources, it is now possible to plan radiation doses by adjusting dwell positions and relative dwell time values. These procedures allow better coverage of the targets while sparing O.A.R.. The recent literature data evidence a significant improvement in local control with no increase in complications. Further studies are needed to better define the dose recommended in both tumour and organs at risk. This is one of the goals of the European study on MRI-guided brachytherapy in locally advanced cervical cancer (E.M.B.R.A.C.E.) protocol (meaning of acronym: an international study on MRI-guided brachytherapy in locally advanced cervical cancer). (authors)

Brachytherapy of endometrial cancers

International Nuclear Information System (INIS)

Peiffert, D.; Hoffstetter, S.; Charra-Brunaud, C.

2003-01-01

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)

Brachytherapy in childhood rhabdomyosarcoma treatment

International Nuclear Information System (INIS)

Novaes, Paulo Eduardo Ribeiro dos Santos

1995-01-01

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 198 , Cesium 137 and Iridium 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)

Artificial neural network based gynaecological image-guided adaptive brachytherapy treatment planning correction of intra-fractional organs at risk dose variation.

Science.gov (United States)

Jaberi, Ramin; Siavashpour, Zahra; Aghamiri, Mahmoud Reza; Kirisits, Christian; Ghaderi, Reza

2017-12-01

Intra-fractional organs at risk (OARs) deformations can lead to dose variation during image-guided adaptive brachytherapy (IGABT). The aim of this study was to modify the final accepted brachytherapy treatment plan to dosimetrically compensate for these intra-fractional organs-applicators position variations and, at the same time, fulfilling the dosimetric criteria. Thirty patients with locally advanced cervical cancer, after external beam radiotherapy (EBRT) of 45-50 Gy over five to six weeks with concomitant weekly chemotherapy, and qualified for intracavitary high-dose-rate (HDR) brachytherapy with tandem-ovoid applicators were selected for this study. Second computed tomography scan was done for each patient after finishing brachytherapy treatment with applicators in situ. Artificial neural networks (ANNs) based models were used to predict intra-fractional OARs dose-volume histogram parameters variations and propose a new final plan. A model was developed to estimate the intra-fractional organs dose variations during gynaecological intracavitary brachytherapy. Also, ANNs were used to modify the final brachytherapy treatment plan to compensate dosimetrically for changes in 'organs-applicators', while maintaining target dose at the original level. There are semi-automatic and fast responding models that can be used in the routine clinical workflow to reduce individually IGABT uncertainties. These models can be more validated by more patients' plans to be able to serve as a clinical tool.

Artificial neural network based gynaecological image-guided adaptive brachytherapy treatment planning correction of intra-fractional organs at risk dose variation

Directory of Open Access Journals (Sweden)

Ramin Jaberi

2017-12-01

Full Text Available Purpose : Intra-fractional organs at risk (OARs deformations can lead to dose variation during image-guided adaptive brachytherapy (IGABT. The aim of this study was to modify the final accepted brachytherapy treatment plan to dosimetrically compensate for these intra-fractional organs-applicators position variations and, at the same time, fulfilling the dosimetric criteria. Material and methods : Thirty patients with locally advanced cervical cancer, after external beam radiotherapy (EBRT of 45-50 Gy over five to six weeks with concomitant weekly chemotherapy, and qualified for intracavitary high-dose-rate (HDR brachytherapy with tandem-ovoid applicators were selected for this study. Second computed tomography scan was done for each patient after finishing brachytherapy treatment with applicators in situ. Artificial neural networks (ANNs based models were used to predict intra-fractional OARs dose-volume histogram parameters variations and propose a new final plan. Results : A model was developed to estimate the intra-fractional organs dose variations during gynaecological intracavitary brachytherapy. Also, ANNs were used to modify the final brachytherapy treatment plan to compensate dosimetrically for changes in ‘organs-applicators’, while maintaining target dose at the original level. Conclusions : There are semi-automatic and fast responding models that can be used in the routine clinical workflow to reduce individually IGABT uncertainties. These models can be more validated by more patients’ plans to be able to serve as a clinical tool.

High versus low-dose rate brachytherapy for cervical cancer.

Science.gov (United States)

Patankar, Sonali S; Tergas, Ana I; Deutsch, Israel; Burke, William M; Hou, June Y; Ananth, Cande V; Huang, Yongmei; Neugut, Alfred I; Hershman, Dawn L; Wright, Jason D

2015-03-01

Brachytherapy plays an important role in the treatment of cervical cancer. While small trials have shown comparable survival outcomes between high (HDR) and low-dose rate (LDR) brachytherapy, little data is available in the US. We examined the utilization of HDR brachytherapy and analyzed the impact of type of brachytherapy on survival for cervical cancer. Women with stages IB2-IVA cervical cancer treated with primary (external beam and brachytherapy) radiotherapy between 2003-2011 and recorded in the National Cancer Database (NCDB) were analyzed. Generalized linear mixed models and Cox proportional hazards regression were used to examine predictors of HDR brachytherapy use and the association between HDR use and survival. A total of 10,564 women including 2681 (25.4%) who received LDR and 7883 (74.6%) that received HDR were identified. Use of HDR increased from 50.2% in 2003 to 83.9% in 2011 (Puse of HDR. While patients in the Northeast were more likely to receive HDR therapy, there were no other clinical or socioeconomic characteristics associated with receipt of HDR. In a multivariable Cox model, survival was similar between the HDR and LDR groups (HR=0.93; 95% CI 0.83-1.03). Similar findings were noted in analyses stratified by stage and histology. Kaplan-Meier analyses demonstrated no difference in survival based on type of brachytherapy for stage IIB (P=0.68), IIIB (P=0.17), or IVA (P=0.16) tumors. The use of HDR therapy has increased rapidly. Overall survival is similar for LDR and HDR brachytherapy. Copyright © 2015 Elsevier Inc. All rights reserved.

BRIT manual after loading brachytherapy kit for intracavitary: initial experience

International Nuclear Information System (INIS)

Aggarwal, Lalit M.; Mandal, Abhijit; Asthana, Anupam K.; Shahi, Uday P.; Pradhan, Satyajit

2007-01-01

Brachytherapy continues to serve as an important and rapidly evolving tool in the management of cancer. Technological developments in the last two decades have dramatic impact on the safe practice of brachytherapy. A wide range of brachytherapy sources and equipment are available for new therapeutic possibilities. However, decision making with regard to new brachytherapy facilities are need based and depend on the patient load, socioeconomic status of the patients, and funds available with the institution. Remote afterloading equipments are fast replacing the Manual After Loading (MAL) systems. However, keeping in view the large number of patients, who can not afford expensive treatment, the utility of manual after loading system which is inexpensive, cannot be ignored

Inverse planning in brachytherapy from radium to high rate 192 iridium afterloading

International Nuclear Information System (INIS)

Lahanas, M.; Mould, R.F.; Baltas, D.; Karauzakis, K.; Giannouli, S.; Baltas, D.

2004-01-01

We consider the inverse planning problem in brachytherapy, i.e. the problem to determine an optimal number of catheters, number of sources for low-dose rate brachytherapy (LDR) and the optimal dwell times for high-dose rate brachytherapy (HDR) necessary to obtain an optimal as possible dose distribution. Starting from the 1930s, inverse planning for LDR brachytherapy used geometrically derived rules to determine the optimal placement of sources in order to achieve a uniform dose distribution of a specific level in planes, spheres and cylinders. Rules and nomograms were derived which still are widely used. With the rapid development of 3D imaging technologies and the rapidly increasing computer power we have now entered the new era of computer-based inverse planning in brachytherapy. The inverse planning is now an optimisation process adapted to the individual geometry of the patient. New inverse planning optimisation algorithms are anatomy-based that consider the real anatomy of the tumour and the organs at risk (OAR). Computer-based inverse planning considers various effects such as stability of solutions for seed misplacements which cannot ever be solved analytically without gross simplifications. In the last few years multiobjective (MO) inverse planning algorithms have been developed which recognise the MO optimisation problem which is inherent in inverse planning in brachytherapy. Previous methods used a trial and error method to obtain a satisfactory solution. MO optimisation replaces this trial and error process by presenting a representative set of dose distributions that can be obtained. With MO optimisation it is possible to obtain information that can be used to obtain the optimum number of catheters, their position and the optimum distribution of dwell times for HDR brachytherapy. For LDR brachytherapy also the stability of solutions due to seed migration can also be improved. A spectrum of alternative solutions is available and the treatment planner

Statistical analysis of MRI-only based dose planning

DEFF Research Database (Denmark)

Korsholm, M. E.; Waring, L. W.; Paulsen, Rasmus Reinhold

2012-01-01

. MRIonly based RT eliminates these errors and reduce the time and costs of a CT scan. The aim of this study is to investigate the dosimetric differences of a treatment plan when the dose calculation is based on MRI as compared to CT. Materials and Methods: Four diagnostic groups are investigated; 12...... as a clinically approved treatment plan. The treatment planning software is Eclipse v.10.0 (Varian Medical Systems). The dose calculation based on MRI data is evaluated in two different ways; a homogeneous density assigned MRI (MRI unit), where the entire body is assigned an HU equal to water and a heterogeneous...... density assigned MRI (MRI bulk) where in addition the CT segmented bone is transferred to the MRI and assigned an age dependent HU based on ICRU report 46. The CT based clinical treatment plan and structure set are registered to the corresponding MRI unit and MRI bulk. The body is outlined on both the MRI...

Effect of pH grade on polymer-gel dosimeter and its brachytherapy application

International Nuclear Information System (INIS)

Spevacek, V.; Hrbacek, J.; Dvorak, P.; Cechak, T.; Novotny, J.

2003-01-01

To evaluate impact of pH grade on characteristics of polymer-gel dosimeter and its application in dose distribution verification in brachytherapy. A polymer-gel dosimeter based on radiation induced polymerization and crosslinking of acrylic monomers (acrylic acid, N,N' methylen-bis-acrylamide) was investigated with respect to its pH grade. pH grade of a dosimeter was varied by concentration of natrium hydroxide. Afterwards, dosimeter was split into several samples which were uniformly irradiated with Co-60 gamma rays. The range of doses applied was usually from 0 to 50 Gy with the main interest in region up to 20 Gy. Evaluation of dosimeter dose response was performed using MRI (T2). Dose response curves obtained were evaluated with respect to pH grade as a parameter. In parallel, there was studied temperature resistance (melting temperature) of gels with various pH grade. pH grade modified polymer-gel dosimeter was then used to compare dose distribution calculated with brachytherapy treatment planning system for simple irradiation geometry with Ir-192 HDR source. Additionaly, Monte Carlo calculated data were also included in the brachytherapy study. There was observed effect of pH grade on dose-response curve parameters (slope of linear fit, background response, linear range and maximum measurable dose). In general, the lower pH grade the higher sensitivity. Another positive effect of decreased pH grade is significantly higher maximum measurable dose. Maximum melting temperature of a gel was observed with pH grade between 3.5 and 4. For both higher and lower pH grades the melting temperature was lower. Using pH modified polymer-gel dosimeter simple brachytherapy dose distribution was measured and compared with calculated and Monte Carlo simulated data. There was observed strong dependence of dose-response relationship on pH grade of polymer-gel dosimeter resulting in significant improvement of dosimeter characteristics, namely sensitivity, applicable range of

LDR vs. HDR brachytherapy for localized prostate cancer: the view from radiobiological models.

Science.gov (United States)

King, Christopher R

2002-01-01

Permanent LDR brachytherapy and temporary HDR brachytherapy are competitive techniques for clinically localized prostate radiotherapy. Although a randomized trial will likely never be conducted comparing these two forms of brachytherapy, a comparative radiobiological modeling analysis proves useful in understanding some of their intrinsic differences, several of which could be exploited to improve outcomes. Radiobiological models based upon the linear quadratic equations are presented for fractionated external beam, fractionated (192)Ir HDR brachytherapy, and (125)I and (103)Pd LDR brachytherapy. These models incorporate the dose heterogeneities present in brachytherapy based upon patient-derived dose volume histograms (DVH) as well as tumor doubling times and repair kinetics. Radiobiological parameters are normalized to correspond to three accepted clinical risk factors based upon T-stage, PSA, and Gleason score to compare models with clinical series. Tumor control probabilities (TCP) for LDR and HDR brachytherapy (as monotherapy or combined with external beam) are compared with clinical bNED survival rates. Predictions are made for dose escalation with HDR brachytherapy regimens. Model predictions for dose escalation with external beam agree with clinical data and validate the models and their underlying assumptions. Both LDR and HDR brachytherapy achieve superior tumor control when compared with external beam at conventional doses (LDR brachytherapy as boost achieves superior tumor control than when used as monotherapy. Stage for stage, both LDR and current HDR regimens achieve similar tumor control rates, in agreement with current clinical data. HDR monotherapy with large-dose fraction sizes might achieve superior tumor control compared with LDR, especially if prostate cancer possesses a high sensitivity to dose fractionation (i.e., if the alpha/beta ratio is low). Radiobiological models support the current clinical evidence for equivalent outcomes in localized

Defining the value framework for prostate brachytherapy using patient-centered outcome metrics and time-driven activity-based costing.

Science.gov (United States)

Thaker, Nikhil G; Pugh, Thomas J; Mahmood, Usama; Choi, Seungtaek; Spinks, Tracy E; Martin, Neil E; Sio, Terence T; Kudchadker, Rajat J; Kaplan, Robert S; Kuban, Deborah A; Swanson, David A; Orio, Peter F; Zelefsky, Michael J; Cox, Brett W; Potters, Louis; Buchholz, Thomas A; Feeley, Thomas W; Frank, Steven J

2016-01-01

Value, defined as outcomes over costs, has been proposed as a measure to evaluate prostate cancer (PCa) treatments. We analyzed standardized outcomes and time-driven activity-based costing (TDABC) for prostate brachytherapy (PBT) to define a value framework. Patients with low-risk PCa treated with low-dose-rate PBT between 1998 and 2009 were included. Outcomes were recorded according to the International Consortium for Health Outcomes Measurement standard set, which includes acute toxicity, patient-reported outcomes, and recurrence and survival outcomes. Patient-level costs to 1 year after PBT were collected using TDABC. Process mapping and radar chart analyses were conducted to visualize this value framework. A total of 238 men were eligible for analysis. Median age was 64 (range, 46-81). Median followup was 5 years (0.5-12.1). There were no acute Grade 3-5 complications. Expanded Prostate Cancer Index Composite 50 scores were favorable, with no clinically significant changes from baseline to last followup at 48 months for urinary incontinence/bother, bowel bother, sexual function, and vitality. Ten-year outcomes were favorable, including biochemical failure-free survival of 84.1%, metastasis-free survival 99.6%, PCa-specific survival 100%, and overall survival 88.6%. TDABC analysis demonstrated low resource utilization for PBT, with 41% and 10% of costs occurring in the operating room and with the MRI scan, respectively. The radar chart allowed direct visualization of outcomes and costs. We successfully created a visual framework to define the value of PBT using the International Consortium for Health Outcomes Measurement standard set and TDABC costs. PBT is associated with excellent outcomes and low costs. Widespread adoption of this methodology will enable value comparisons across providers, institutions, and treatment modalities. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

WE-DE-201-12: Thermal and Dosimetric Properties of a Ferrite-Based Thermo-Brachytherapy Seed

International Nuclear Information System (INIS)

Warrell, G; Shvydka, D; Parsai, E I

2016-01-01

Purpose: The novel thermo-brachytherapy (TB) seed provides a simple means of adding hyperthermia to LDR prostate permanent implant brachytherapy. The high blood perfusion rate (BPR) within the prostate motivates the use of the ferrite and conductive outer layer design for the seed cores. We describe the results of computational analyses of the thermal properties of this ferrite-based TB seed in modelled patient-specific anatomy, as well as studies of the interseed and scatter (ISA) effect. Methods: The anatomies (including the thermophysical properties of the main tissue types) and seed distributions of 6 prostate patients who had been treated with LDR brachytherapy seeds were modelled in the finite element analysis software COMSOL, using ferrite-based TB and additional hyperthermia-only (HT-only) seeds. The resulting temperature distributions were compared to those computed for patient-specific seed distributions, but in uniform anatomy with a constant blood perfusion rate. The ISA effect was quantified in the Monte Carlo software package MCNP5. Results: Compared with temperature distributions calculated in modelled uniform tissue, temperature distributions in the patient-specific anatomy were higher and more heterogeneous. Moreover, the maximum temperature to the rectal wall was typically ∼1 °C greater for patient-specific anatomy than for uniform anatomy. The ISA effect of the TB and HT-only seeds caused a reduction in D90 similar to that found for previously-investigated NiCu-based seeds, but of a slightly smaller magnitude. Conclusion: The differences between temperature distributions computed for uniform and patient-specific anatomy for ferrite-based seeds are significant enough that heterogeneous anatomy should be considered. Both types of modelling indicate that ferrite-based seeds provide sufficiently high and uniform hyperthermia to the prostate, without excessively heating surrounding tissues. The ISA effect of these seeds is slightly less than that

WE-DE-201-12: Thermal and Dosimetric Properties of a Ferrite-Based Thermo-Brachytherapy Seed

Energy Technology Data Exchange (ETDEWEB)

Warrell, G; Shvydka, D; Parsai, E I [University of Toledo Medical Center, Toledo, OH (United States)

2016-06-15

Purpose: The novel thermo-brachytherapy (TB) seed provides a simple means of adding hyperthermia to LDR prostate permanent implant brachytherapy. The high blood perfusion rate (BPR) within the prostate motivates the use of the ferrite and conductive outer layer design for the seed cores. We describe the results of computational analyses of the thermal properties of this ferrite-based TB seed in modelled patient-specific anatomy, as well as studies of the interseed and scatter (ISA) effect. Methods: The anatomies (including the thermophysical properties of the main tissue types) and seed distributions of 6 prostate patients who had been treated with LDR brachytherapy seeds were modelled in the finite element analysis software COMSOL, using ferrite-based TB and additional hyperthermia-only (HT-only) seeds. The resulting temperature distributions were compared to those computed for patient-specific seed distributions, but in uniform anatomy with a constant blood perfusion rate. The ISA effect was quantified in the Monte Carlo software package MCNP5. Results: Compared with temperature distributions calculated in modelled uniform tissue, temperature distributions in the patient-specific anatomy were higher and more heterogeneous. Moreover, the maximum temperature to the rectal wall was typically ∼1 °C greater for patient-specific anatomy than for uniform anatomy. The ISA effect of the TB and HT-only seeds caused a reduction in D90 similar to that found for previously-investigated NiCu-based seeds, but of a slightly smaller magnitude. Conclusion: The differences between temperature distributions computed for uniform and patient-specific anatomy for ferrite-based seeds are significant enough that heterogeneous anatomy should be considered. Both types of modelling indicate that ferrite-based seeds provide sufficiently high and uniform hyperthermia to the prostate, without excessively heating surrounding tissues. The ISA effect of these seeds is slightly less than that

Definition of medical event is to be based on the total source strength for evaluation of permanent prostate brachytherapy: A report from the American Society for Radiation Oncology.

Science.gov (United States)

Nag, Subir; Demanes, D Jeffrey; Hagan, Michael; Rivard, Mark J; Thomadsen, Bruce R; Welsh, James S; Williamson, Jeffrey F

2011-10-01

The Nuclear Regulatory Commission deems it to be a medical event (ME) if the total dose delivered differs from the prescribed dose by 20% or more. A dose-based definition of ME is not appropriate for permanent prostate brachytherapy as it generates too many spurious MEs and thereby creates unnecessary apprehension in patients, and ties up regulatory bodies and the licensees in unnecessary and burdensome investigations. A more suitable definition of ME is required for permanent prostate brachytherapy. The American Society for Radiation Oncology (ASTRO) formed a working group of experienced clinicians to review the literature, assess the validity of current regulations, and make specific recommendations about the definition of an ME in permanent prostate brachytherapy. The working group found that the current definition of ME in §35.3045 as "the total dose delivered differs from the prescribed dose by 20 percent or more" was not suitable for permanent prostate brachytherapy since the prostate volume (and hence the resultant calculated prostate dose) is dependent on the timing of the imaging, the imaging modality used, the observer variability in prostate contouring, the planning margins used, inadequacies of brachytherapy treatment planning systems to calculate tissue doses, and seed migration within and outside the prostate. If a dose-based definition for permanent implants is applied strictly, many properly executed implants would be improperly classified as an ME leading to a detrimental effect on brachytherapy. The working group found that a source strength-based criterion, of >20% of source strength prescribed in the post-procedure written directive being implanted outside the planning target volume is more appropriate for defining ME in permanent prostate brachytherapy. ASTRO recommends that the definition of ME for permanent prostate brachytherapy should not be dose based but should be based upon the source strength (air-kerma strength) administered.

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

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...

The evolution of brachytherapy treatment planning

International Nuclear Information System (INIS)

Rivard, Mark J.; Venselaar, Jack L. M.; Beaulieu, Luc

2009-01-01

Brachytherapy is a mature treatment modality that has benefited from technological advances. Treatment planning has advanced from simple lookup tables to complex, computer-based dose-calculation algorithms. The current approach is based on the AAPM TG-43 formalism with recent advances in acquiring single-source dose distributions. However, this formalism has clinically relevant limitations for calculating patient dose. Dose-calculation algorithms are being developed based on Monte Carlo methods, collapsed cone, and solving the linear Boltzmann transport equation. In addition to improved dose-calculation tools, planning systems and brachytherapy treatment planning will account for material heterogeneities, scatter conditions, radiobiology, and image guidance. The AAPM, ESTRO, and other professional societies are working to coordinate clinical integration of these advancements. This Vision 20/20 article provides insight into these endeavors.

High-risk clinical target volume delineation in CT-guided cervical cancer brachytherapy - Impact of information from FIGO stage with or without systematic inclusion of 3D documentation of clinical gynecological examination

Energy Technology Data Exchange (ETDEWEB)

Hegazy, Neamat [Dept. of Radiotherapy, Comprehensive Cancer Centre Vienna, Medical Univ. of Vienna, Vienna (Austria); Dept. of Clinical Oncology, Medical Univ. of Alexandria, Alexandria (Egypt); Poetter Rickard; Kirisits, Christian [Dept. of Radiotherapy, Comprehensive Cancer Centre Vienna, Medical Univ. of Vienna, Vienna (Austria); Christian Doppler Lab. for Medical Radiation Research for Radiation Oncology, Medical Univ. Vienna (Austria); Berger, Daniel; Federico, Mario; Sturdza, Alina; Nesvacil, Nicole [Dept. of Radiotherapy, Comprehensive Cancer Centre Vienna, Medical Univ. of Vienna, Vienna (Austria)], e-mail: nicole.nesvacil@meduniwien.ac.at

2013-10-15

Purpose: The aim of the study was to improve computed tomography (CT)-based high-risk clinical target volume (HR CTV) delineation protocols for cervix cancer patients, in settings without any access to magnetic resonance imaging (MRI) at the time of brachytherapy. Therefore the value of a systematic integration of comprehensive three-dimensional (3D) documentation of repetitive gynecological examination for CT-based HR CTV delineation protocols, in addition to information from FIGO staging, was investigated. In addition to a comparison between reference MRI contours and two different CT-based contouring methods (using complementary information from FIGO staging with or without additional 3D clinical drawings), the use of standardized uterine heights was also investigated. Material and methods: Thirty-five cervix cancer patients with CT- and MR-images and 3D clinical drawings at time of diagnosis and brachytherapy were included. HR CTV{sub stage} was based on CT information and FIGO stage. HR CTV{sub stage} {sub +3Dclin} was contoured on CT using FIGO stage and 3D clinical drawing. Standardized HR CTV heights were: 1/1, 2/3 and 1/2 of uterine height. MRI-based HR CTV was delineated independently. Resulting widths, thicknesses, heights, and volumes of HR CTV{sub stage}, HR CTV{sub stage+3Dclin} and MRI-based HR CTV contours were compared. Results: The overall normalized volume ratios (mean{+-}SD of CT/MRI{sub ref} volume) of HR CTV{sub stage} and HR{sub stage+3Dclin} were 2.6 ({+-}0.6) and 2.1 ({+-}0.4) for 1/1 and 2.3 ({+-}0.5) and 1.8 ({+-}0.4), for 2/3, and 1.9 ({+-}0.5) and 1.5 ({+-}0.3), for 1/2 of uterine height. The mean normalized widths were 1.5{+-}0.2 and 1.2{+-}0.2 for HR CTV{sub stage} and HR CTV{sub stage+3Dclin}, respectively (p < 0.05). The mean normalized heights for HR CTV{sub stage} and HR CTV{sub stage+3Dclin} were both 1.7{+-}0.4 for 1/1 (p < 0.05.), 1.3{+-}0.3 for 2/3 (p < 0.05) and 1.1{+-}0.3 for 1/2 of uterine height. Conclusion: CT-based HR

Development of an adjoint sensitivity field-based treatment-planning technique for the use of newly designed directional LDR sources in brachytherapy.

Science.gov (United States)

Chaswal, V; Thomadsen, B R; Henderson, D L

2012-02-21

The development and application of an automated 3D greedy heuristic (GH) optimization algorithm utilizing the adjoint sensitivity fields for treatment planning to assess the advantage of directional interstitial prostate brachytherapy is presented. Directional and isotropic dose kernels generated using Monte Carlo simulations based on Best Industries model 2301 I-125 source are utilized for treatment planning. The newly developed GH algorithm is employed for optimization of the treatment plans for seven interstitial prostate brachytherapy cases using mixed sources (directional brachytherapy) and using only isotropic sources (conventional brachytherapy). All treatment plans resulted in V100 > 98% and D90 > 45 Gy for the target prostate region. For the urethra region, the D10(Ur), D90(Ur) and V150(Ur) and for the rectum region the V100cc, D2cc, D90(Re) and V90(Re) all are reduced significantly when mixed sources brachytherapy is used employing directional sources. The simulations demonstrated that the use of directional sources in the low dose-rate (LDR) brachytherapy of the prostate clearly benefits in sparing the urethra and the rectum sensitive structures from overdose. The time taken for a conventional treatment plan is less than three seconds, while the time taken for a mixed source treatment plan is less than nine seconds, as tested on an Intel Core2 Duo 2.2 GHz processor with 1GB RAM. The new 3D GH algorithm is successful in generating a feasible LDR brachytherapy treatment planning solution with an extra degree of freedom, i.e. directionality in very little time.

Development of an adjoint sensitivity field-based treatment-planning technique for the use of newly designed directional LDR sources in brachytherapy

Science.gov (United States)

Chaswal, V.; Thomadsen, B. R.; Henderson, D. L.

2012-02-01

The development and application of an automated 3D greedy heuristic (GH) optimization algorithm utilizing the adjoint sensitivity fields for treatment planning to assess the advantage of directional interstitial prostate brachytherapy is presented. Directional and isotropic dose kernels generated using Monte Carlo simulations based on Best Industries model 2301 I-125 source are utilized for treatment planning. The newly developed GH algorithm is employed for optimization of the treatment plans for seven interstitial prostate brachytherapy cases using mixed sources (directional brachytherapy) and using only isotropic sources (conventional brachytherapy). All treatment plans resulted in V100 > 98% and D90 > 45 Gy for the target prostate region. For the urethra region, the D10Ur, D90Ur and V150Ur and for the rectum region the V100cc, D2cc, D90Re and V90Re all are reduced significantly when mixed sources brachytherapy is used employing directional sources. The simulations demonstrated that the use of directional sources in the low dose-rate (LDR) brachytherapy of the prostate clearly benefits in sparing the urethra and the rectum sensitive structures from overdose. The time taken for a conventional treatment plan is less than three seconds, while the time taken for a mixed source treatment plan is less than nine seconds, as tested on an Intel Core2 Duo 2.2 GHz processor with 1GB RAM. The new 3D GH algorithm is successful in generating a feasible LDR brachytherapy treatment planning solution with an extra degree of freedom, i.e. directionality in very little time.

SU-F-J-163: In Vivo Quantification of Sequence Parameter Effect On Geometric Distortion Caused by Implanted Titanium Brachytherapy Applicator

Energy Technology Data Exchange (ETDEWEB)

Sullivan, T; Diak, A; Surucu, M; Yacoub, J; Harkenrider, M; Shea, S [Loyola University Chicago, Maywood, IL (United States)

2016-06-15

Purpose: The use of MR to plan and evaluate brachytherapy treatment for cervical cancer is increasing given the availability of MR conditional or safe applicators and MRI’s proven superiority to CT for characterizing soft tissue lesions. The titanium applicators, however, cause geometric distortions or imaging artifacts, which reduce the utility of MRI for dosimetry. We sought to quantify the observed volume of the same applicator on a previously optimized T2 sequence in comparison to the conventional T2 sequence and CT obtained for brachytherapy planning. Methods: Prior work with testing in phantoms showed that increases in readout bandwidth yielded reductions in artifact area and distortion measurements even with voxel increases. Following IRB approval, nine patients with titanium tandem & ovoid applicator (Varian Medical Systems) in place were scanned with a standard periprocedural protocol which included sagittal T2 fast spin echo (FSE) acquisition (res 0.98×0.78×4.0 mm{sup 3}; BW 200Hz). An additional T2-weighted FSE sequence (res 0.98×0.98×3–4 mm{sup 3}; BW500Hz) with increased readout bandwidth, readout voxel size, and echo train length was added to the protocol. Volume measurements of the applicator (from tip to cervical stop) were hand-segmented in Velocity AI 3.1 (Velocity Medical Solutions) for the two T2 FSE sequences and a planning CT obtained shortly after MRI. Differences were analyzed using a paired t-test. Results: Average apparent volumes of the applicator on standard T2 sequence, decreased bandwidth T2 sequence and CT were 5.922±1.283 cm{sup 3}, 4.544±1.524 cm3, and 2.304±0.509 cm{sup 3} respectively. Conclusion: Apparent volumes of a brachytherapy applicator can be compared in vivo. The modified sequence results in decreased apparent size of the cervical applicator. Both MR sequence volumes were larger than the planning CT, which was expected. Future work will focus on the diagnostic quality of the new sequence and quantifying any

Comparison of Measurements of the Uterus and Cervix Obtained by Magnetic Resonance and Transabdominal Ultrasound Imaging to Identify the Brachytherapy Target in Patients With Cervix Cancer

International Nuclear Information System (INIS)

Dyk, Sylvia van; Kondalsamy-Chennakesavan, Srinivas; Schneider, Michal; Bernshaw, David; Narayan, Kailash

2014-01-01

Purpose: To compare measurements of the uterus and cervix obtained with magnetic resonance imaging (MRI) and transabdominal ultrasound to determine whether ultrasound can identify the brachytherapy target and be used to guide conformal brachytherapy planning and treatment for cervix cancer. Methods and Materials: Consecutive patients undergoing curative treatment with radiation therapy between January 2007 and March 2012 were included in the study. Intrauterine applicators were inserted into the uterine canal while patients were anesthetized. Images were obtained by MRI and transabdominal ultrasound in the longitudinal axis of the uterus with the applicator in treatment position. Measurements were taken at the anterior and posterior surface of the uterus at 2.0-cm intervals along the applicator, from the external os to the tip of the applicator. Data were analyzed using Bland Altman plots examining bias and 95% limits of agreement. Results: A total of 192 patients contributed 1668 measurements of the cervix and uterus. Mean (±SD) differences of measurements between imaging modalities at the anterior and posterior uterine surface ranged from 1.5 (±3.353) mm to 3.7 (±3.856) mm, and −1.46 (±3.308) mm to 0.47 (±3.502) mm, respectively. The mean differences were less than 3 mm in the cervix. The mean differences were less than 1.5 mm at all measurement points on the posterior surface. Conclusion: Differences in the measurements of the cervix and uterus obtained by MRI and ultrasound were within clinically acceptable limits. Transabdominal ultrasound can be substituted for MRI in defining the target volume for conformal brachytherapy treatment of cervix cancer

Comparison of Measurements of the Uterus and Cervix Obtained by Magnetic Resonance and Transabdominal Ultrasound Imaging to Identify the Brachytherapy Target in Patients With Cervix Cancer

Energy Technology Data Exchange (ETDEWEB)

Dyk, Sylvia van, E-mail: sylvia.vandyk@petermac.org [Radiation Therapy Services, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Kondalsamy-Chennakesavan, Srinivas [Rural Clinical School, University of Queensland, Toowoomba, Queensland (Australia); Schneider, Michal [Department of Medical Imaging and Radiation Science, Monash University, Clayton, Victoria (Australia); Bernshaw, David [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Narayan, Kailash [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Department of Obstetrics and Gynaecology, Melbourne University, Melbourne, Victoria (Australia)

2014-03-15

Purpose: To compare measurements of the uterus and cervix obtained with magnetic resonance imaging (MRI) and transabdominal ultrasound to determine whether ultrasound can identify the brachytherapy target and be used to guide conformal brachytherapy planning and treatment for cervix cancer. Methods and Materials: Consecutive patients undergoing curative treatment with radiation therapy between January 2007 and March 2012 were included in the study. Intrauterine applicators were inserted into the uterine canal while patients were anesthetized. Images were obtained by MRI and transabdominal ultrasound in the longitudinal axis of the uterus with the applicator in treatment position. Measurements were taken at the anterior and posterior surface of the uterus at 2.0-cm intervals along the applicator, from the external os to the tip of the applicator. Data were analyzed using Bland Altman plots examining bias and 95% limits of agreement. Results: A total of 192 patients contributed 1668 measurements of the cervix and uterus. Mean (±SD) differences of measurements between imaging modalities at the anterior and posterior uterine surface ranged from 1.5 (±3.353) mm to 3.7 (±3.856) mm, and −1.46 (±3.308) mm to 0.47 (±3.502) mm, respectively. The mean differences were less than 3 mm in the cervix. The mean differences were less than 1.5 mm at all measurement points on the posterior surface. Conclusion: Differences in the measurements of the cervix and uterus obtained by MRI and ultrasound were within clinically acceptable limits. Transabdominal ultrasound can be substituted for MRI in defining the target volume for conformal brachytherapy treatment of cervix cancer.

Interstitial prostate brachytherapy. LDR-PDR-HDR

International Nuclear Information System (INIS)

Kovacs, Gyoergy; Hoskin, Peter

2013-01-01

The first comprehensive overview of interstitial brachytherapy for the management of local or locally advanced prostate cancer. Written by an interdisciplinary team who have been responsible for the successful GEC-ESTRO/EAU Teaching Course. Discusses in detail patient selection, the results of different methods, the role of imaging, and medical physics issues. Prostate brachytherapy has been the subject of heated debate among surgeons and the proponents of the various brachytherapy methods. This very first interdisciplinary book on the subject provides a comprehensive overview of innovations in low dose rate (LDR), high dose rate (HDR), and pulsed dose rate (PDR) interstitial brachytherapy for the management of local or locally advanced prostate cancer. In addition to detailed chapters on patient selection and the use of imaging in diagnostics, treatment guidance, and implantation control, background chapters are included on related medical physics issues such as treatment planning and quality assurance. The results obtained with the different treatment options and the difficult task of salvage treatment are fully discussed. All chapters have been written by internationally recognized experts in their fields who for more than a decade have formed the teaching staff responsible for the successful GEC-ESTRO/EAU Prostate Brachytherapy Teaching Course. This book will be invaluable in informing residents and others of the scientific background and potential of modern prostate brachytherapy. It will also prove a useful source of up-to-date information for those who specialize in prostate brachytherapy or intend to start an interstitial brachytherapy service.

National audit of a system for rectal contact brachytherapy

Directory of Open Access Journals (Sweden)

Laia Humbert-Vidan

2017-01-01

Full Text Available Background and purpose: Contact brachytherapy is used for the treatment of early rectal cancer. An overview of the current status of quality assurance of the rectal contact brachytherapy systems in the UK, based on a national audit, was undertaken in order to assist users in optimising their own practices. Material and methods: Four UK centres using the Papillon 50 contact brachytherapy system were audited. Measurements included beam quality, output and radiation field size and uniformity. Test frequencies and tolerances were reviewed and compared to both existing recommendations and published reviews on other kV and electronic brachytherapy systems. External validation of dosimetric measurements was provided by the National Physical Laboratory. Results: The maximum host/audit discrepancy in beam quality determination was 6.5%; this resulted in absorbed dose variations of 0.2%. The host/audit agreement in absorbed dose determination was within 2.2%. The median of the radiation field uniformity measurements was 2.7% and the host/audit agreement in field size was within 1 mm. Test tolerances and frequencies were within the national recommendations for kV units. Conclusions: The dosimetric characterisation of the Papillon 50 was validated by the audit measurements for all participating centres, thus providing reassurance that the implementation had been performed within the standards stated in previously published audit work and recommendations for kV and electronic brachytherapy units. However, optimised and standardised quality assurance testing could be achieved by reducing some methodological differences observed. Keywords: Contact brachytherapy, Electronic brachytherapy, Audit

SU-F-T-55: Reproducibility of Interstitial HDR Brachytherapy Plans

Energy Technology Data Exchange (ETDEWEB)

Lee, S; Ellis, R; Traughber, B; Podder, T [University Hospitals Case Medical Center, Cleveland, OH (United States)

2016-06-15

Purpose: Treating gynecological cancers with interstitial high-dose-rate (HDR) brachytherapy requires precise reconstruction of catheter positions to obtain accurate dosimetric plans. In this study, we investigated the degree of reproducibility of dosimetric plans for Syed HDR brachytherapy. Methods: We randomly selected five patients having cervix-vaginal cancer who were recently treated in our clinic with interstitial HDR brachytherapy with a prescription dose of 25–30 Gy in five fractions. Interstitial needles/catheters were placed under fluoroscopic guidance and intra-operative 3T MRI scan was performed to confirm the desired catheter placement for adequate target volume coverage. A CT scan was performed and fused with the MRI for delineating high-risk CTV (HR-CTV), intermediate-risk CTV (IR-CTV) and OARs. HDR treatment plans were generated using Oncentra planning software. A single plan was used for all five fractions of treatment for each patient. For this study, we took the original clinical plan and removed all the reconstructed catheters from the plan keeping the original contours unchanged. Then, we manually reconstructed all the catheters and entered the same dwell time from the first original clinical plan. The dosimetric parameters studied were: D90 for HR-CTV and IR-CV, and D2cc for bladder, rectum, sigmoid and bowel. Results: The mean of absolute differences in dosimetric coverage (D90) were (range): 1.3% (1.0–2.0%) and 2.0% (0.9–3.6%) for HR-CTV and IR-CTV, respectively. In case of OARs, the mean of absolute variations in D2cc were (range): 4.7% (0.7–8.9%) for bladder, 1.60% (0.3–3.2%) for rectum, 1.6% (0–3.9%) for sigmoid, and 1.8% (0–5.1%) for bowel. Conclusion: Overall, the reproducibility of interstitial HDR plans was within clinically acceptable limit. Observed maximum variation in D2cc for bladder. If number of catchers and dwell points were relatively low or any one catheter was heavily loaded, then reproducibility of the plan

Clinical feasibility of combined intracavitary/interstitial brachytherapy in locally advanced cervical cancer employing MRI with a tandem/ring applicator in situ and virtual preplanning of the interstitial component

International Nuclear Information System (INIS)

Fokdal, Lars; Tanderup, Kari; Hokland, Steffen Bjerre; Røhl, Lisbeth; Pedersen, Erik Morre; Nielsen, Søren Kynde; Paludan, Merete; Lindegaard, Jacob Christian

2013-01-01

Purpose: To investigate the reproducibility of virtually planned needles, changes in DVH parameters and clinical feasibility of combined intracavitary/interstitial (IC/IS) pulsed dose rate brachytherapy (PDR-BT) for locally advanced cervical cancer based on 3D MRI preplanning. Material and methods: Fifty-eight consecutively patients accrued in the EMBRACE study were included. Treatment was initiated with external beam radiotherapy and cisplatin. Three BT implants and MRI with the applicator in situ were performed in all patients, i.e. week 5 (BT0), week 6 (BT1) and week 7 (BT2) of the treatment. BT0 was only used for preplanning of subsequent implantations, whereas BT1 and BT2 comprised 2 equal sized fractions of PDR BT. Results: Based on BT0, 24 patients (41%) were selected for a combined IC/IS implant at BT1 and BT2. Patients treated with IC/IS BT had significantly larger tumours compared with patients treated with IC BT only (p < 0.03). Additional time in general anaesthesia for the IC/IS component was on average 16 min. The number of preplanned virtual needles was 5.3 ± 2.7 compared to 5.3 ± 2.9 and 5.4 ± 3.0 needles implanted at BT1 and BT2, respectively (p = 0.72). Planned needle implantation depth was 33 ± 15 mm compared to 30 ± 10 mm at BT1 and 29 ± 11 mm at BT2 (p = 0.04). In the 24 patients selected for IC/IS BT both the virtual IC/IS plan (BT0) and the actually delivered plan (BT1 + BT2) significantly increased D90 and D100 for HR CTV (p < 0.01) and reduced D2cc for sigmoid (p < 0.01) and bowel (p = 0.04) compared to the optimised IC preplan (BT0). IC/IS BT was only associated with minor morbidity, which was resolved at a 3-month follow up. Conclusion: Combined IC/IS BT based on full 3D MRI preplanning is clinically feasible. The virtual preplanned needle positions are reproducible at subsequent BT applications leading to significantly improved DVH parameters and a clinically feasible and fast implant procedure

Construction balance analysis of dose rate medium brachytherapy TDS

International Nuclear Information System (INIS)

Sandi Parapak

2011-01-01

One of the most important part of brachytherapy instrument design activities is analyze by determining the centroid point of construction in order to maintain the balance of brachytherapy instrument, either during operation as well as when transported. Operation of brachytherapy is not only done in one place so it is necessary to balance the analysis of the forces at the time did not move, moved on the horizontal floor and sloping floor. Calculation approach who is done to calculate the weight of mechanical components on each module, and then calculate the centroid of each module, for the balance of forces analysis performed with the assumption at the time of brachytherapy in the position of not moving on a horizontal floor, moved from a place to another on the horizontal floor and on the floor with sloping angle 30°. Base on the results of this analysis are expected to balance the four wheels can move without slipping at the time of decline or incline. Also, results of analysis can be used in designing a mobile construction brachytherapy taking into consideration the aesthetic ideal, easy to operate, ensure the safety of equipment, operator and patient. (author)

A comparison of complications between ultrasound-guided prostate brachytherapy and open prostate brachytherapy

International Nuclear Information System (INIS)

Benoit, Ronald M.; Naslund, Michael J.; Cohen, Jeffrey K.

2000-01-01

Purpose: Prostate brachytherapy has reemerged during the 1990s as a treatment for clinically localized prostate cancer. The renewed popularity of prostate brachytherapy is largely due to the use of transrectal ultrasound of the prostate, which allows for more accurate isotope placement within the prostate when compared to the open approach. The present study investigates whether this improved cancer control is at the expense of increased morbidity by comparing the morbidity after transrectal ultrasound-guided prostate brachytherapy to the morbidity after prostate brachytherapy performed via an open approach. Methods and Materials: All men in the Medicare population who underwent prostate brachytherapy in the year 1991 were identified. These men were further stratified into those men who underwent prostate brachytherapy via an open approach and the men who underwent prostate brachytherapy with ultrasound guidance. All subsequent inpatient, outpatient, and physician (Part B) Medicare claims for these men from the years 1991-1993 were then analyzed to determine outcomes. Results: In the year 1991, 2124 men in the Medicare population underwent prostate brachytherapy. An open approach was used in 715 men (33.7%), and ultrasound guidance was used in 1409 men (66.3%). Mean age for both cohorts was 73.7 years with a range of 50.7-92.8 years for the ultrasound group and 60.6-92.1 years for the open group. A surgical procedure for the relief of bladder outlet obstruction was performed in 122 men (8.6%) in the ultrasound group and in 54 men (7.6%) in the open group. An artificial urinary sphincter was placed in 2 men (0.14%) in the ultrasound group and in 2 men (0.28%) in the open group. A penile prosthesis was implanted in 10 men (0.71%) in the ultrasound group and in 4 men (0.56%) in the open group. A diagnosis code for urinary incontinence was carried by 95 men (6.7%) in the ultrasound group and by 45 men (6.3%) in the open group. A diagnosis code for erectile dysfunction

Calculated and measured brachytherapy dosimetry parameters in water for the Xoft Axxent X-Ray Source: an electronic brachytherapy source.

Science.gov (United States)

Rivard, Mark J; Davis, Stephen D; DeWerd, Larry A; Rusch, Thomas W; Axelrod, Steve

2006-11-01

A new x-ray source, the model S700 Axxent X-Ray Source (Source), has been developed by Xoft Inc. for electronic brachytherapy. Unlike brachytherapy sources containing radionuclides, this Source may be turned on and off at will and may be operated at variable currents and voltages to change the dose rate and penetration properties. The in-water dosimetry parameters for this electronic brachytherapy source have been determined from measurements and calculations at 40, 45, and 50 kV settings. Monte Carlo simulations of radiation transport utilized the MCNP5 code and the EPDL97-based mcplib04 cross-section library. Inter-tube consistency was assessed for 20 different Sources, measured with a PTW 34013 ionization chamber. As the Source is intended to be used for a maximum of ten treatment fractions, tube stability was also assessed. Photon spectra were measured using a high-purity germanium (HPGe) detector, and calculated using MCNP. Parameters used in the two-dimensional (2D) brachytherapy dosimetry formalism were determined. While the Source was characterized as a point due to the small anode size, S700 Source exhibited depth dose behavior similar to low-energy photon-emitting low dose rate sources 125I and l03Pd, yet with capability for variable and much higher dose rates and subsequently adjustable penetration capabilities. This paper presents the calculated and measured in-water brachytherapy dosimetry parameters for the model S700 Source at the aforementioned three operating voltages.

High dose rate brachytherapy for oral cancer.

Science.gov (United States)

Yamazaki, Hideya; Yoshida, Ken; Yoshioka, Yasuo; Shimizutani, Kimishige; Furukawa, Souhei; Koizumi, Masahiko; Ogawa, Kazuhiko

2013-01-01

Brachytherapy results in better dose distribution compared with other treatments because of steep dose reduction in the surrounding normal tissues. Excellent local control rates and acceptable side effects have been demonstrated with brachytherapy as a sole treatment modality, a postoperative method, and a method of reirradiation. Low-dose-rate (LDR) brachytherapy has been employed worldwide for its superior outcome. With the advent of technology, high-dose-rate (HDR) brachytherapy has enabled health care providers to avoid radiation exposure. This therapy has been used for treating many types of cancer such as gynecological cancer, breast cancer, and prostate cancer. However, LDR and pulsed-dose-rate interstitial brachytherapies have been mainstays for head and neck cancer. HDR brachytherapy has not become widely used in the radiotherapy community for treating head and neck cancer because of lack of experience and biological concerns. On the other hand, because HDR brachytherapy is less time-consuming, treatment can occasionally be administered on an outpatient basis. For the convenience and safety of patients and medical staff, HDR brachytherapy should be explored. To enhance the role of this therapy in treatment of head and neck lesions, we have reviewed its outcomes with oral cancer, including Phase I/II to Phase III studies, evaluating this technique in terms of safety and efficacy. In particular, our studies have shown that superficial tumors can be treated using a non-invasive mold technique on an outpatient basis without adverse reactions. The next generation of image-guided brachytherapy using HDR has been discussed. In conclusion, although concrete evidence is yet to be produced with a sophisticated study in a reproducible manner, HDR brachytherapy remains an important option for treatment of oral cancer.

Utilization of prostate brachytherapy for low risk prostate cancer: Is the decline overstated?

OpenAIRE

Joseph Safdieh; Andrew Wong; Joseph P. Weiner; David Schwartz; David Schreiber

2016-01-01

Purpose : Several prior studies have suggested that brachytherapy utilization has markedly decreased, coinciding with the recent increased utilization of intensity modulated radiation therapy, as well as an increase in urologist-owned centers. We sought to investigate the brachytherapy utilization in a large, hospital-based registry. Material and methods: Men with prostate cancer diagnosed between 2004-2012 and treated with either external beam radiation and/or prostate brachytherapy ...

Feasibility and safety of GliaSite brachytherapy in treatment of CNS tumors following neurosurgical resection

Directory of Open Access Journals (Sweden)

Wernicke A

2010-01-01

Full Text Available Purpose: To investigate feasibility and safety of GliaSite brachytherapy for treatment of central nervous system (CNS tumors following neurosurgical resection. We report mature results of long-term follow-up, outcomes and toxicity. Materials and Methods: In the period from 2004 to 2007, 10 consecutive adult patients with recurrent, newly diagnosed, and metastatic brain malignancies underwent GliaSite brachytherapy following maximally safe neurosurgical resection. While 6/10 (60% patients were treated for recurrence, having previously been treated with external beam radiotherapy (EBRT, 4/10 (40% received radiotherapy (RT for the first time. A median dose of 52.0 Gy (range, 45.0 - 60.0 Gy was prescribed to 0.5 cm - 1.0 cm from the balloon surface. Radiation Therapy Oncology Group (RTOG criteria were used to assess toxicities associated with this technique. Follow-up was assessed with MRI scans and was available on all enrolled patients. Results: Median follow-up was 38 months (range, 18 - 57 months. Mean size of GliaSite balloon was 3.4 cm (range, 2.0 - 4.0 cm. Median survival was 14.0 months for the entire cohort after the treatment. The 17.6 and 16.0 months average survival for newly diagnosed and recurrent high grade gliomas (HGG, respectively, translated into a three-month improvement in survival in patients with newly diagnosed HGG compared to historical controls (P = 0.033. There were no RTOG grades 3 or 4 acute or late toxicities. Follow-up magnetic resonance imaging (MRI imaging did not identify radiation necrosis. Conclusions: Our data indicate that treatment with GliaSite brachytherapy is feasible, safe and renders acceptable local control, acute and long-term toxicities. We are embarking on testing larger numbers of patients with this treatment modality.

High dose rate brachytherapy for oral cancer

International Nuclear Information System (INIS)

Yamazaki, Hideya; Yoshida, Ken; Yoshioka, Yasuo; Shimizutani, Kimishige; Koizumi, Masahiko; Ogawa, Kazuhiko; Furukawa, Souhei

2013-01-01

Brachytherapy results in better dose distribution compared with other treatments because of steep dose reduction in the surrounding normal tissues. Excellent local control rates and acceptable side effects have been demonstrated with brachytherapy as a sole treatment modality, a postoperative method, and a method of reirradiation. Low-dose-rate (LDR) brachytherapy has been employed worldwide for its superior outcome. With the advent of technology, high-dose-rate (HDR) brachytherapy has enabled health care providers to avoid radiation exposure. This therapy has been used for treating many types of cancer such as gynecological cancer, breast cancer, and prostate cancer. However, LDR and pulsed-dose-rate interstitial brachytherapies have been mainstays for head and neck cancer. HDR brachytherapy has not become widely used in the radiotherapy community for treating head and neck cancer because of lack of experience and biological concerns. On the other hand, because HDR brachytherapy is less time-consuming, treatment can occasionally be administered on an outpatient basis. For the convenience and safety of patients and medical staff, HDR brachytherapy should be explored. To enhance the role of this therapy in treatment of head and neck lesions, we have reviewed its outcomes with oral cancer, including Phase I/II to Phase III studies, evaluating this technique in terms of safety and efficacy. In particular, our studies have shown that superficial tumors can be treated using a non-invasive mold technique on an outpatient basis without adverse reactions. The next generation of image-guided brachytherapy using HDR has been discussed. In conclusion, although concrete evidence is yet to be produced with a sophisticated study in a reproducible manner, HDR brachytherapy remains an important option for treatment of oral cancer. (author)

Sigmoid Colon is an Unexpected Organ at Risk in Brachytherapy for Cervix Cancer

International Nuclear Information System (INIS)

Ffrrcsi, H.F.; Mrcpfrcr, I.B.; Appleby, H.

2006-01-01

Purpose: To identify organs at risk (OAR) and analyze the dose volume histograms (DVHs) for intracavitary brachytherapy in cancer of the cervix. Late toxicities are our concern in treatment of cancer cervix especially as it is presenting in younger age population. Material and Methods: Patients with cancer of the cervix were treated using CT and MRI compatible, high dose rate, (HDR) applicators. CT images were acquired with the intra-uterine tube and colpostats in place and subsequently imported into Varian Brachyvision planning software. We identified the gross tumour volume (GTV) and organs at risk (OARs) and analyzed the dose distribution using dose volume histograms (DVHs). Doses were calculated according to ICRU 38. Critical tissue DVHs were analysed following the American Brachytherapy Society rules. Dose points are recorded as the dose encompassed by the greatest contiguous I cm3, 2 cm3, and 5 cm3 volumes in the plan. Results: We found the sigmoid colon to be a relatively immobile structure that repeatedly received doses in excess of 70% of the intended point A dose. The only solution in order to bring sigmoid DVHs within 5% toxicity limits was to reduce the dose to point A. Planning images and DVHs for the OARs are shown as an example of our work. Conclusion: The recto-sigmoid colon is identified as an unexpected OAR in a majority of cervix brachytherapy plans. A new consensus on the DVH limit of this structure will be needed in the era of CT planned brachytherapy, if arbitrary dose reductions to point A are to be the solution to the problem of sigmoid DVHs that exceed conventional tolerance limits

Comparison between Japanese and French interstitial brachytherapy for head and neck cancer

International Nuclear Information System (INIS)

Nose, Takayuki; Koizumi, Masahiko; Nishiyama, Kinji; Inoue, Toshihiko

2001-01-01

Interstitial brachytherapy is the optimal radiotherapy modality for head and neck cancer because the highest dose conformity can be achieved, and implanted tubes can move synchronously with the tumor movement. Compared with radical surgery, interstitial brachytherapy can achieve equivalent local control with less morbidity and less functional deficit. In Japan, because of technical limitations, interstitial brachytherapy has been confined to treatment of small tongue cancers. To improve our head and neck cancer treatment, technical limitations should be eliminated and a wider indication for interstitial brachytherapy should be achieved. In France, interstitial brachytherapy has been technically more developed and widely indicated than in Japan. We analyzed the differences between Japanese (Osaka) and French (Lyon and Nancy) techniques, to improve our interstitial brachytherapy. Implant devices and techniques: French applicators (Longcip 1) are more flexible and more suitable for loop techniques of the soft palate, the base of the tongue, and the vallecula, than applicators available in Japan. Various implant techniques are established especially for the oropharynx in France. Mandibular protection: Lead blocks used in France can more effectively shield the mandible than our silicone spacers. We showed the dosimetric results in an experimental treatment setting. Dose specification: The five-mm dose specification method used in Japan can work only for easy cases, such as small oral tongue cancers and mouth floor cancers. For complicated implants, such as for the oropharynx, the CTV-based dose specification method used in France is essential for sufficient irradiation. Indications: The indication for head and neck interstitial brachytherapy in Japan is limited mostly to small oral tongue cancers. The indication in France is wider, including the oral cavity, the oropharynx, and postoperative cases. We can refine our head and neck cancer treatment if we combine French

Automated intraoperative calibration for prostate cancer brachytherapy

International Nuclear Information System (INIS)

Kuiran Chen, Thomas; Heffter, Tamas; Lasso, Andras; Pinter, Csaba; Abolmaesumi, Purang; Burdette, E. Clif; Fichtinger, Gabor

2011-01-01

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.

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 accordance...

SU-E-T-523: Investigation of Various MR-Compatible Shielding Materials for Direction Modulated Brachytherapy (DMBT) Tandem Applicator for Cervical Cancer Treatment

Energy Technology Data Exchange (ETDEWEB)

Safigholi, H; Soliman, A; Song, W [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, U of T, Toronto, Ontario (Canada); Han, D [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, U of T, Toronto, Ontario (Canada); University of California, San Diego, La Jolla, CA (United States); Meigooni, A Soleimani [Comprehensive Cancer Center of Nevada, Las Vegas, NV (United States); Scanderbeg, D [UCSD Medical Center, La Jolla, CA (United States)

2015-06-15

Purpose: To evaluate various shielding materials such as Gold (Au), Osmium (Os), Tantalum (Ta), and Tungsten (W) based alloys for use with a novel intensity modulation capable direction modulated brachytherapy (DMBT) tandem applicator for image guided cervical cancer HDR brachytherapy. Methods: The novel MRI-compatible DMBT tandem, made from nonmagnetic tungsten-alloy rod with diameter of 5.4 mm, has 6 symmetric peripheral holes of 1.3 mm diameter with 2.05 mm distance from the center for a high degree intensity modulation capacity. The 0.3 mm thickness of bio-compatible plastic tubing wraps the tandem. MCNPX was used for Monte Carlo simulations of the shields and the mHDR Ir-192 V2 source. MC-generated 3D dose matrices of different shielding materials of Au, Os, Ta, and W with 1 mm3 resolution were imported into an in-house-coded inverse optimization planning system to evaluate 19 clinical patient plans. Prescription dose was 15Gy. All plans were normalized to receive the same HRCTV D90. Results: In general, the plan qualities for various shielding materials were similar. The OAR D2cc for bladder was very similar for Au, Os, and Ta with 11.64±2.30Gy. For W, it was very close 11.65±2.30Gy. The sigmoid D2cc was 9.82±2.46Gy for Au and Os while it was 9.84±2.48Gy for Ta and W. The rectum D2cc was 7.44±3.06Gy for Au, 7.43±3.07Gy for Os, 7.48±3.05Gy for Ta, and 7.47±3.05Gy for W. The HRCTV D98 and V100 were very close with 16.37±1.87 Gy and 97.37±1.93 Gy, on average, respectively. Conclusion: Various MRI-compatible shielding alloys were investigated for the DMBT tandem applicator. The clinical plan qualities were not significantly different among these various alloys, however. Therefore, the candidate metals (or in combination) can be used to select best alloys for MRI image guided cervical cancer brachytherapy using the novel DMBT applicator that is capable of unprecedented level of intensity modulation.

SU-E-T-523: Investigation of Various MR-Compatible Shielding Materials for Direction Modulated Brachytherapy (DMBT) Tandem Applicator for Cervical Cancer Treatment

International Nuclear Information System (INIS)

Safigholi, H; Soliman, A; Song, W; Han, D; Meigooni, A Soleimani; Scanderbeg, D

2015-01-01

Purpose: To evaluate various shielding materials such as Gold (Au), Osmium (Os), Tantalum (Ta), and Tungsten (W) based alloys for use with a novel intensity modulation capable direction modulated brachytherapy (DMBT) tandem applicator for image guided cervical cancer HDR brachytherapy. Methods: The novel MRI-compatible DMBT tandem, made from nonmagnetic tungsten-alloy rod with diameter of 5.4 mm, has 6 symmetric peripheral holes of 1.3 mm diameter with 2.05 mm distance from the center for a high degree intensity modulation capacity. The 0.3 mm thickness of bio-compatible plastic tubing wraps the tandem. MCNPX was used for Monte Carlo simulations of the shields and the mHDR Ir-192 V2 source. MC-generated 3D dose matrices of different shielding materials of Au, Os, Ta, and W with 1 mm3 resolution were imported into an in-house-coded inverse optimization planning system to evaluate 19 clinical patient plans. Prescription dose was 15Gy. All plans were normalized to receive the same HRCTV D90. Results: In general, the plan qualities for various shielding materials were similar. The OAR D2cc for bladder was very similar for Au, Os, and Ta with 11.64±2.30Gy. For W, it was very close 11.65±2.30Gy. The sigmoid D2cc was 9.82±2.46Gy for Au and Os while it was 9.84±2.48Gy for Ta and W. The rectum D2cc was 7.44±3.06Gy for Au, 7.43±3.07Gy for Os, 7.48±3.05Gy for Ta, and 7.47±3.05Gy for W. The HRCTV D98 and V100 were very close with 16.37±1.87 Gy and 97.37±1.93 Gy, on average, respectively. Conclusion: Various MRI-compatible shielding alloys were investigated for the DMBT tandem applicator. The clinical plan qualities were not significantly different among these various alloys, however. Therefore, the candidate metals (or in combination) can be used to select best alloys for MRI image guided cervical cancer brachytherapy using the novel DMBT applicator that is capable of unprecedented level of intensity modulation

Calculated and measured brachytherapy dosimetry parameters in water for the Xoft Axxent X-Ray Source: An electronic brachytherapy source

International Nuclear Information System (INIS)

Rivard, Mark J.; Davis, Stephen D.; DeWerd, Larry A.; Rusch, Thomas W.; Axelrod, Steve

2006-01-01

A new x-ray source, the model S700 Axxent trade mark sign X-Ray Source (Source), has been developed by Xoft Inc. for electronic brachytherapy. Unlike brachytherapy sources containing radionuclides, this Source may be turned on and off at will and may be operated at variable currents and voltages to change the dose rate and penetration properties. The in-water dosimetry parameters for this electronic brachytherapy source have been determined from measurements and calculations at 40, 45, and 50 kV settings. Monte Carlo simulations of radiation transport utilized the MCNP5 code and the EPDL97-based mcplib04 cross-section library. Inter-tube consistency was assessed for 20 different Sources, measured with a PTW 34013 ionization chamber. As the Source is intended to be used for a maximum of ten treatment fractions, tube stability was also assessed. Photon spectra were measured using a high-purity germanium (HPGe) detector, and calculated using MCNP. Parameters used in the two-dimensional (2D) brachytherapy dosimetry formalism were determined. While the Source was characterized as a point due to the small anode size, P (5) were 0.20, 0.24, and 0.29 for the 40, 45, and 50 kV voltage settings, respectively. For 1 125 I and 103 Pd, yet with capability for variable and much higher dose rates and subsequently adjustable penetration capabilities. This paper presents the calculated and measured in-water brachytherapy dosimetry parameters for the model S700 Source at the aforementioned three operating voltages

Trends in the Utilization of Brachytherapy in Cervical Cancer in the United States

Energy Technology Data Exchange (ETDEWEB)

Han, Kathy, E-mail: Kathy.Han@rmp.uhn.on.ca [Radiation Medicine Program, Princess Margaret Hospital, University Health Network, Toronto, Ontario (Canada); Milosevic, Michael; Fyles, Anthony [Radiation Medicine Program, Princess Margaret Hospital, University Health Network, Toronto, Ontario (Canada); Pintilie, Melania [Department of Biostatistics, Princess Margaret Hospital, Toronto, Ontario (Canada); Viswanathan, Akila N. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital, Boston, Massachusetts (United States)

2013-09-01

Purpose: To determine the trends in brachytherapy use in cervical cancer in the United States and to identify factors and survival benefits associated with brachytherapy treatment. Methods and Materials: Using the Surveillance, Epidemiology, and End Results (SEER) database, we identified 7359 patients with stages IB2-IVA cervical cancer treated with external beam radiation therapy (EBRT) between 1988 and 2009. Propensity score matching was used to adjust for differences between patients who received brachytherapy and those who did not from 2000 onward (after the National Cancer Institute alert recommending concurrent chemotherapy). Results: Sixty-three percent of the 7359 women received brachytherapy in combination with EBRT, and 37% received EBRT alone. The brachytherapy utilization rate has decreased from 83% in 1988 to 58% in 2009 (P<.001), with a sharp decline of 23% in 2003 to 43%. Factors associated with higher odds of brachytherapy use include younger age, married (vs single) patients, earlier years of diagnosis, earlier stage and certain SEER regions. In the propensity score-matched cohort, brachytherapy treatment was associated with higher 4-year cause-specific survival (CSS; 64.3% vs 51.5%, P<.001) and overall survival (OS; 58.2% vs 46.2%, P<.001). Brachytherapy treatment was independently associated with better CSS (hazard ratio [HR], 0.64; 95% confidence interval [CI], 0.57-0.71), and OS (HR 0.66; 95% CI, 0.60 to 0.74). Conclusions: This population-based analysis reveals a concerning decline in brachytherapy utilization and significant geographic disparities in the delivery of brachytherapy in the United States. Brachytherapy use is independently associated with significantly higher CSS and OS and should be implemented in all feasible cases.

Utilization of prostate brachytherapy for low risk prostate cancer: Is the decline overstated?

Science.gov (United States)

Safdieh, Joseph; Wong, Andrew; Weiner, Joseph P; Schwartz, David; Schreiber, David

2016-08-01

Several prior studies have suggested that brachytherapy utilization has markedly decreased, coinciding with the recent increased utilization of intensity modulated radiation therapy, as well as an increase in urologist-owned centers. We sought to investigate the brachytherapy utilization in a large, hospital-based registry. Men with prostate cancer diagnosed between 2004-2012 and treated with either external beam radiation and/or prostate brachytherapy were abstracted from the National Cancer Database. In order to be included, men had to be clinically staged as T1c-T2aNx-0Mx-0, Gleason 6, PSA ≤ 10.0 ng/ml. Descriptive statistics were used to analyze brachytherapy utilization over time and were compared via χ(2). Multivariate logistic regression was used to assess for covariables associated with increased brachytherapy usage. There were 89,413 men included in this study, of which 37,054 (41.6%) received only external beam radiation, and 52,089 (58.4%) received prostate brachytherapy. The use of brachytherapy declined over time from 62.9% in 2004 to 51.3% in 2012 (p facilities (60.8% in 2004 to 47.0% in 2012, p facilities (63.7% in 2004 to 53.0% in 2012, p facilities than those who lived further. The use of intensity modulated radiation therapy increased during this same time period from 18.4% in 2004 to 38.2% in 2012 (p usage. In this hospital-based registry, prostate brachytherapy usage has declined for low risk prostate cancer as intensity modulated radiation therapy usage has increased. However, it still remains the treatment of choice for 51.3% of patients as of 2012.

Severe rectal complications after prostate brachytherapy

International Nuclear Information System (INIS)

Wallner, Kent; Sutlief, Stephen; Bergsagel, Carl; Merrick, Gregory S.

2015-01-01

Purpose: Some investigators have reported severe rectal complications after brachytherapy. Due to the low number of such events, their relationship to dosimetric parameters has not been well characterized. Methods and materials: A total of 3126 patients were treated with low dose rate brachytherapy from 1998 through 2010. 2464 had implant alone, and 313 had implant preceded by 44–46 Gy supplemental external beam radiation (EBRT). Post-implant dosimetry was based on a CT scan obtained on the day of implant, generally within 30 min of the procedure. Every patient’s record was reviewed for occurrence of rectal complications. Results: Eight of 2464 patients (0.32%) treated with brachytherapy alone developed a radiation-related rectal fistula. Average prostatic and rectal dose parameters were moderately higher for fistula patients than for patients without a severe rectal complication. For instance, the average R100 was 1.2 ± 0.75 cc for fistula patients, versus 0.37 ± 0.88 cc for non-fistula patients. However, the fistula patients’ values were well within the range of values for patients without a rectal complication. Four patients had some attempt at repair or reconstruction, but long-term functional outcomes were not favorable. Conclusions: Rectal fistulas are a very uncommon potential complication of prostate brachytherapy, which can occur even in the setting of acceptable day 0 rectal doses. Their occurrence is not easily explained by standard dosimetric or clinical factors

Interference between PET and MRI sub-systems in a silicon-photomultiplier-based PET/MRI system

International Nuclear Information System (INIS)

Yamamoto, Seiichi; Watabe, Hiroshi; Kanai, Yasukazu; Hatazawa, Jun; Aoki, Masaaki; Sugiyama, Eiji; Watabe, Tadashi; Imaizumi, Masao; Shimosegawa, Eku

2011-01-01

The silicon-photomultiplier (Si-PM) is a promising photodetector, especially for integrated PET/MRI systems, due to its small size, high gain, and low sensitivity to static magnetic fields. The major problem using a Si-PM-based PET system within the MRI system is the interference between the PET and MRI units. We measured the interference by combining a Si-PM-based PET system with a permanent-magnet MRI system. When the RF signal-induced pulse height exceeded the lower energy threshold level of the PET system, interference between the Si-PM-based PET system and MRI system was detected. The prompt as well as the delayed coincidence count rates of the Si-PM-based PET system increased significantly. These noise counts produced severe artifacts on the reconstructed images of the Si-PM-based PET system. In terms of the effect of the Si-PM-based PET system on the MRI system, although no susceptibility artifact was observed on the MR images, electronic noise from the PET detector ring was detected by the RF coil and reduced the signal-to-noise ratio (S/N) of the MR images. The S/N degradation of the MR images was reduced when the distance between the RF coil and the Si-PM-based PET system was increased. We conclude that reducing the interference between the PET and MRI systems is essential for achieving the optimum performance of integrated Si-PM PET/MRI systems.

Who Really Benefits from 3D-Based Planning of Brachytherapy for Cervical Cancer?

Science.gov (United States)

Ha, In Bong; Jeong, Bae Kwon; Kang, Ki Mun; Jeong, Hojin; Lee, Yun Hee; Choi, Hoon Sik; Lee, Jong Hak; Choi, Won Jun; Shin, Jeong Kyu; Song, Jin Ho

2018-04-30

Although intracavitary radiotherapy (ICR) is essential for the radiation therapy of cervical cancer, few institutions in Korea perform 3-dimensional (3D)-based ICR. To identify patients who would benefit from 3D-based ICR, dosimetric parameters for tumor targets and organs at risk (OARs) were compared between 2-dimensional (2D)- and 3D-based ICR. Twenty patients with locally advanced cervical cancer who underwent external beam radiation therapy (EBRT) following 3D-based ICR were retrospectively evaluated. New 2D-based plans based on the Manchester system were developed. Tumor size was measured by magnetic resonance imaging. The mean high risk clinical target volume (HR-CTV) D90 value was about 10% lower for 2D- than for 3D-based plans (88.4% vs. 97.7%; P = 0.068). Tumor coverage did not differ between 2D- and 3D-based plans in patients with tumors ≤ 4 cm at the time of brachytherapy, but the mean HR-CTV D90 values in patients with tumors > 4 cm were significantly higher for 3D-based plans than for 2D-based plans (96.0% vs. 78.1%; P = 0.017). Similar results were found for patients with tumors > 5 cm initially. Other dosimetric parameters for OARs were similar between 2D- and 3D-based plans, except that mean sigmoid D2cc was higher for 2D- than for 3D-based plans (67.5% vs. 58.8%; P = 0.043). These findings indicate that 3D-based ICR plans improve tumor coverage while satisfying the dose constraints for OARs. 3D-based ICR should be considered in patients with tumors > 4 cm size at the time of brachytherapy or > 5 cm initially.

SU-E-T-525: Dose Volume Histograms (DVH) Analysis and Comparison with ICRU Point Doses in MRI Guided HDR Brachytherapy for Cervical Cancer

Energy Technology Data Exchange (ETDEWEB)

Badkul, R; McClinton, C; Kumar, P; Mitchell, M [University of Kansas Medical Center, Kansas City, KS (United States)

2014-06-01

Purpose: Brachytherapy plays a crucial role in management of cervix cancer. MRI compatible applicators have made it possible to accurately delineate gross-target-volume(GTV) and organs-at-risk(OAR) volumes, as well as directly plan, optimize and adapt dose-distribution for each insertion. We sought to compare DVH of tumor-coverage and OARs to traditional Point-A, ICRU-38 bladder and rectum point-doses for four different planning-techniques. Methods: MRI based 3D-planning was performed on Nucletron-Oncentra-TPS for 3 selected patients with varying tumor-sizes and anatomy. GTV,high-risk-clinical-target-volume(HR-CTV), intermediate-risk-clinical-target-volume(IR-CTV) and OARs: rectum, bladder, sigmoid-colon, vaginal-mucosa were delineated. Three conventionally used techniques: mg-Radium-equivalent(RaEq),equal-dwell-weights(EDW), Medical-College-of-Wisconsin proposed points-optimization (MCWO) and a manual-graphical-optimization(MGO) volume-coverage based technique were applied for each patient. Prescription was 6Gy delivered to point-A in Conventional techniques (RaEq, EDW, MCWO). For MGO, goal was to achieve 90%-coverage (D90) to HR-CTV with prescription-dose. ICRU point doses for rectum and bladder, point-A doses, DVH-doses for HR-CTV-D90,0.1cc-volume(D0.1),1ccvolume( D1),2cc-volume(D2) were collected for all plans and analyzed . Results: Mean D90 for HR-CTV normalized to MGO were 0.89,0.84,0.9,1.0 for EDW, RaEq, MCWO, MGO respectively. Mean point-A doses were 21.7% higher for MGO. Conventional techniques with Point-A prescriptions under covered HR-CTV-D90 by average of 12% as compared to MGO. Rectum, bladder and sigmoid doses were highest in MGO-plans for ICRU points as well as D0.1,D1 and D2 doses. Among conventional-techniques, rectum and bladder ICRU and DVH doses(0.1,1,2cc) were not significantly different (within 7%).Rectum D0.1 provided good estimation of ICRU-rectum-point doses (within 3.9%),rectum D0.1 were higher from 0.8 to 3.9% while bladder D0

American Brachytherapy Society consensus report for accelerated partial breast irradiation using interstitial multicatheter brachytherapy.

Science.gov (United States)

Hepel, Jaroslaw T; Arthur, Douglas; Shaitelman, Simona; Polgár, Csaba; Todor, Dorin; Zoberi, Imran; Kamrava, Mitchell; Major, Tibor; Yashar, Catheryn; Wazer, David E

To develop a consensus report for the quality practice of accelerated partial breast irradiation (APBI) using interstitial multicatheter brachytherapy (IMB). The American Brachytherapy Society Board appointed an expert panel with clinical and research experience with breast brachytherapy to provide guidance for the current practice of IMB. This report is based on a comprehensive literature review with emphasis on randomized data and expertise of the panel. Randomized trials have demonstrated equivalent efficacy of APBI using IMB compared with whole breast irradiation for select patients with early-stage breast cancer. Several techniques for placement of interstitial catheters are described, and importance of three-dimensional planning with appropriate optimization is reviewed. Optimal target definition is outlined. Commonly used dosing schemas include 50 Gy delivered in pulses of 0.6-0.8 Gy/h using pulsed-dose-rate technique and 34 Gy in 10 fractions, 32 Gy in eight fractions, or 30 Gy in seven fractions using high-dose-rate technique. Potential toxicities and strategies for toxicity avoidance are described in detail. Dosimetric constraints include limiting whole breast volume that receives ≥50% of prescription dose to 0.75 (>0.85 preferred), V 150  < 45 cc, and V 200  < 14 cc. Using an optimal implant technique coupled with optimal planning and appropriate dose constraints, a low rate of toxicity and a good-to-excellent cosmetic outcome of ≥90% is expected. IMB is an effective technique to deliver APBI for appropriately selected women with early-stage breast cancer. This consensus report has been created to assist clinicians in the appropriate practice of APBI using IMB. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Development of brachytherapy medium doserate

International Nuclear Information System (INIS)

Atang Susila; Ari Satmoko; Ahmad Rifai; Kristiyanti

2010-01-01

Brachytherapy has proven to be an effective treatment for different types of cancers and it become a common treatment modality in most radiotherapy clinics. PRPN has had experience in development of Low Dose Rate Brachytherapy for cervix cancer treatment. However the treatment process using LDR device needs 5 hours in time that the patient feel uncomfort. Therefore PRPN develops Medium Dose Rate Brachytherapy with radiation activity not more than 5 Currie. The project is divided into two stages. Purchasing of TPS software and TDS design are held in 2010, and the construction will be in 2011. (author)

Brachytherapy

Science.gov (United States)

... the use of a type of energy, called ionizing radiation, to kill cancer cells and shrink tumors. External ... In all cases of brachytherapy, the source of radiation is encapsulated ... non-radioactive metallic capsule. This prevents the radioactive materials ...

Erectile function after prostate brachytherapy

International Nuclear Information System (INIS)

Merrick, Gregory S.; Butler, Wayne M.; Wallner, Kent E.; Galbreath, Robert W.; Anderson, Richard L.; Kurko, Brian S.; Lief, Jonathan H.; Allen, Zachariah A.

2005-01-01

Purpose: To evaluate erectile function after permanent prostate brachytherapy using a validated patient-administered questionnaire and to determine the effect of multiple clinical, treatment, and dosimetric parameters on penile erectile function. Methods and materials: A total of 226 patients with preimplant erectile function determined by the International Index of Erectile Function (IIEF) questionnaire underwent permanent prostate brachytherapy in two prospective randomized trials between February 2001 and January 2003 for clinical Stage T1c-T2c (2002 American Joint Committee on Cancer) prostate cancer. Of the 226 patients, 132 were potent before treatment and, of those, 128 (97%) completed and returned the IIEF questionnaire after brachytherapy. The median follow-up was 29.1 months. Potency was defined as an IIEF score of ≥13. The clinical, treatment, and dosimetric parameters evaluated included patient age; preimplant IIEF score; clinical T stage; pretreatment prostate-specific antigen level; Gleason score; elapsed time after implantation; preimplant nocturnal erections; body mass index; presence of hypertension or diabetes mellitus; tobacco consumption; the volume of the prostate gland receiving 100%, 150%, and 200% of the prescribed dose (V 100/150/200 ); the dose delivered to 90% of the prostate gland (D 90 ); androgen deprivation therapy; supplemental external beam radiotherapy (EBRT); isotope; prostate volume; planning volume; and radiation dose to the proximal penis. Results: The 3-year actuarial rate of potency preservation was 50.5%. For patients who maintained adequate posttreatment erectile function, the preimplant IIEF score was 29, and in patients with brachytherapy-related ED, the preimplant IIEF score was 25. The median time to the onset of ED was 5.4 months. After brachytherapy, the median IIEF score was 20 in potent patients and 3 in impotent patients. On univariate analysis, the preimplant IIEF score, patient age, presence of nocturnal

CT-image based conformal brachytherapy of breast cancer. The significance of semi-3-D and 3-D treatment planning

International Nuclear Information System (INIS)

Polgar, C.; Major, T.; Somogyi, A.; Takacsi-Nagy, Z.; Mangel, L.C.; Fodor, J.; Nemeth, G.; Forrai, G.; Sulyok, Z.

2000-01-01

In 103 patients with T1-2, N0-1 breast cancer the tumor bed was clipped during breast conserving surgery. Fifty-two of them received boost brachytherapy after 46 to 50 Gy teletherapy and 51 patients were treated with brachytherapy alone via flexible implant tubes. Single double and triple plane implant was used in 6,89 and 8 cases, respectively. The dose of boost brachytherapy and sole brachytherapy prescribed to dose reference points was 3 times 4.75 Gy and 7 times 5.2 Gy, respectively. The positions of dose reference points varied according to the level (2-D, semi-3-D and 3-D) of treatment planning performed. The treatment planning was based on the 3-D reconstruction of the surgical clips, implant tubes and skin points. In all cases the implantations were planned with a semi-3-D technique aided by simulator. In 10 cases a recently developed CT-guided 3-D planning system was used. The semi-3D and 3-D treatment plans were compared to hypothetical 2-D plans using dose-volume histograms and dose non-uniformity ratios. The values of mean central dose, mean skin dose, minimal clip dose, proportion of underdosaged clips and mean target surface dose were evaluated. The accuracy of tumor bed localization and the conformity of planning target volume and treated volume were also analyzed in each technique. Results: With the help of conformal semi-3D and 3D brachytherapy planning we could define reference dose points, active source positions and dwell times individually. This technique decreased the mean skin dose with 22.2% and reduced the possibility of geographical miss. We could achieve the best conformity between the planning target volume and the treated volume with the CT-image based 3-D treatment planning, at the cost of worse dose homogeneity. The mean treated volume was reduced by 25.1% with semi-3-D planning, however, its was increased by 16.2% with 3-D planning, compared to the 2-D planning. (orig.) [de

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.

Utilization of prostate brachytherapy for low risk prostate cancer: Is the decline overstated?

Directory of Open Access Journals (Sweden)

Joseph Safdieh

2016-08-01

Full Text Available Purpose : Several prior studies have suggested that brachytherapy utilization has markedly decreased, coinciding with the recent increased utilization of intensity modulated radiation therapy, as well as an increase in urologist-owned centers. We sought to investigate the brachytherapy utilization in a large, hospital-based registry. Material and methods: Men with prostate cancer diagnosed between 2004-2012 and treated with either external beam radiation and/or prostate brachytherapy were abstracted from the National Cancer Database. In order to be included, men had to be clinically staged as T1c-T2aNx-0Mx-0, Gleason 6, PSA ≤ 10.0 ng/ml. Descriptive statistics were used to analyze brachytherapy utilization over time and were compared via χ2. Multivariate logistic regression was used to assess for covariables associated with increased brachytherapy usage. Results : There were 89,413 men included in this study, of which 37,054 (41.6% received only external beam radiation, and 52,089 (58.4% received prostate brachytherapy. The use of brachytherapy declined over time from 62.9% in 2004 to 51.3% in 2012 (p < 0.001. This decline was noted in both academic facilities (60.8% in 2004 to 47.0% in 2012, p < 0.001 as well as in non-academic facilities (63.7% in 2004 to 53.0% in 2012, p < 0.001. The decline was more pronounced in patients who lived closer to treatment facilities than those who lived further. The use of intensity modulated radiation therapy increased during this same time period from 18.4% in 2004 to 38.2% in 2012 (p < 0.001. On multivariate analysis, treatment at an academic center, increasing age, decreasing distance from the treatment center, and years of diagnosis from 2006-2012 were significantly associated with reduced brachytherapy usage. Conclusions : In this hospital-based registry, prostate brachytherapy usage has declined for low risk prostate cancer as intensity modulated radiation therapy usage has increased. However, it still

Brachytherapy treatment with high dose rate

International Nuclear Information System (INIS)

Santana Rodriguez, Sergio Marcelino; Rodriguez Rodriguez, Lissi Lisbet; Ciscal Chiclana, Onelio Alberto

2009-01-01

Retrospectively analyze results and prognostic factors of cervical cancer patients treated with radio concomitant cisplatin-based chemotherapy, radiation therapy combined modality. Methods: From January 2003 to December 2007, 198 patients with invasive cervical cancer were treated at the Oncology Department of Hospital Robau Celestino Hernandez (brachytherapy performed at INOR). The most common age group was 31 to 40 years. The histology in squamous cell carcinoma accounted for 84.3% of cases. The treatment consisted of external pelvic irradiation and vaginal brachytherapy, high dose rate. Concomitant chemotherapy consisted of cisplatin 40 mg/m2 weekly with a maximum of 70 mg for 5 weeks. Results: 66.2% of patients completed 5 cycles of chemotherapy. The median overall survival was 39 months, overall survival, disease-free survival and survival free of locoregional recurrence at 5 years of 78%, 76% and 78.6% respectively .. We found that clinical stage, histological type (adenocarcinoma worst outcome) were statistically related to level of response. Conclusions: Treatment with external pelvic radiation, brachytherapy and concurrent weekly cisplatin in patients with stage IIIB cervical cancer is feasible in the Chilean public health system, well tolerated and results comparable to international literature. (Author)

Whole-body bone segmentation from MRI for PET/MRI attenuation correction using shape-based averaging

DEFF Research Database (Denmark)

Arabi, Hossein; Zaidi, H.

2016-01-01

Purpose: The authors evaluate the performance of shape-based averaging (SBA) technique for whole-body bone segmentation from MRI in the context of MRI-guided attenuation correction (MRAC) in hybrid PET/MRI. To enhance the performance of the SBA scheme, the authors propose to combine it with stati......Purpose: The authors evaluate the performance of shape-based averaging (SBA) technique for whole-body bone segmentation from MRI in the context of MRI-guided attenuation correction (MRAC) in hybrid PET/MRI. To enhance the performance of the SBA scheme, the authors propose to combine...... it with statistical atlas fusion techniques. Moreover, a fast and efficient shape comparisonbased atlas selection scheme was developed and incorporated into the SBA method. Methods: Clinical studies consisting of PET/CT and MR images of 21 patients were used to assess the performance of the SBA method. In addition...... voting (MV) atlas fusion scheme was also evaluated as a conventional and commonly used method. MRI-guided attenuation maps were generated using the different segmentation methods. Thereafter, quantitative analysis of PET attenuation correction was performed using CT-based attenuation correction...

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, ...

Comparison of urethral diameters for calculating the urethral dose after permanent prostate brachytherapy

International Nuclear Information System (INIS)

Tanaka, Osamu; Hayashi, Shinya; Matsuo, Masayuki; Nakano, Masahiro; Kubota, Yasuaki; Maeda, Sunaho; Ohtakara, Kazuhiro; Deguchi, Takashi; Hoshi, Hiroaki

2007-01-01

No studies have yet evaluated the effects of a dosimetric analysis for different urethral volumes. We therefore evaluated the effects of a dosimetric analysis to determine the different urethral volumes. This study was based on computed tomography/magnetic resonance imaging (CT/MRI) combined findings in 30 patients who had undergone prostate brachytherapy. Postimplant CT/MRI scans were performed 30 days after the implant. The urethra was contoured based on its diameter (8, 6, 4, 2, and 0 mm). The total urethral volume-in cubic centimeters [UrV150/200 (cc)] and percent (UrV150%/200%), of the urethra receiving 150% or 200% of the prescribed dose-and the doses (UrD90/30/5) in Grays to 90%, 30%, and 5% of the urethral volume were measured based on the urethral diameters. The UrV150 (cc) and UrD30 were statistically different between the of 8-, 6-, 4-, 2-, and 0-mm diameters, whereas the UrD5 was statistically different only between the 8-, 6-, and 4-mm diameters. Especially for UrD5, there was an approximately 40-Gy difference between the mean values for the 8- and 0-mm diameters. We recommend that the urethra should be contoured as a 4- to 6-mm diameter circle or one side of a triangle of 5-7 mm. By standardizing the urethral diameter, the urethral dose will be less affected by the total urethral volume. (author)

CT-image based conformal brachytherapy of breast cancer. The significance of semi-3-D and 3-D treatment planning

Energy Technology Data Exchange (ETDEWEB)

Polgar, C.; Major, T.; Somogyi, A.; Takacsi-Nagy, Z.; Mangel, L.C.; Fodor, J.; Nemeth, G. [Orszagos Onkologiai Intezet, Budapest (Hungary). Dept. of Radiotherapy; Forrai, G. [Haynal Imre Univ. of Health Sciences, Budapest (Hungary). Dept. of Radiology; Sulyok, Z. [Orszagos Onkologiai Intezet, Budapest (Hungary). Dept. of Surgery

2000-03-01

In 103 patients with T1-2, N0-1 breast cancer the tumor bed was clipped during breast conserving surgery. Fifty-two of them received boost brachytherapy after 46 to 50 Gy teletherapy and 51 patients were treated with brachytherapy alone via flexible implant tubes. Single double and triple plane implant was used in 6,89 and 8 cases, respectively. The dose of boost brachytherapy and sole brachytherapy prescribed to dose reference points was 3 times 4.75 Gy and 7 times 5.2 Gy, respectively. The positions of dose reference points varied according to the level (2-D, semi-3-D and 3-D) of treatment planning performed. The treatment planning was based on the 3-D reconstruction of the surgical clips, implant tubes and skin points. In all cases the implantations were planned with a semi-3-D technique aided by simulator. In 10 cases a recently developed CT-guided 3-D planning system was used. The semi-3D and 3-D treatment plans were compared to hypothetical 2-D plans using dose-volume histograms and dose non-uniformity ratios. The values of mean central dose, mean skin dose, minimal clip dose, proportion of underdosaged clips and mean target surface dose were evaluated. The accuracy of tumor bed localization and the conformity of planning target volume and treated volume were also analyzed in each technique. Results: With the help of conformal semi-3D and 3D brachytherapy planning we could define reference dose points, active source positions and dwell times individually. This technique decreased the mean skin dose with 22.2% and reduced the possibility of geographical miss. We could achieve the best conformity between the planning target volume and the treated volume with the CT-image based 3-D treatment planning, at the cost of worse dose homogeneity. The mean treated volume was reduced by 25.1% with semi-3-D planning, however, its was increased by 16.2% with 3-D planning, compared to the 2-D planning. (orig.) [German] Bei 103 Patientinnen mit Mammakarzinom der Stadien T1

A novel method for accurate needle-tip identification in trans-rectal ultrasound-based high-dose-rate prostate brachytherapy.

Science.gov (United States)

Zheng, Dandan; Todor, Dorin A

2011-01-01

In real-time trans-rectal ultrasound (TRUS)-based high-dose-rate prostate brachytherapy, the accurate identification of needle-tip position is critical for treatment planning and delivery. Currently, needle-tip identification on ultrasound images can be subject to large uncertainty and errors because of ultrasound image quality and imaging artifacts. To address this problem, we developed a method based on physical measurements with simple and practical implementation to improve the accuracy and robustness of needle-tip identification. Our method uses measurements of the residual needle length and an off-line pre-established coordinate transformation factor, to calculate the needle-tip position on the TRUS images. The transformation factor was established through a one-time systematic set of measurements of the probe and template holder positions, applicable to all patients. To compare the accuracy and robustness of the proposed method and the conventional method (ultrasound detection), based on the gold-standard X-ray fluoroscopy, extensive measurements were conducted in water and gel phantoms. In water phantom, our method showed an average tip-detection accuracy of 0.7 mm compared with 1.6 mm of the conventional method. In gel phantom (more realistic and tissue-like), our method maintained its level of accuracy while the uncertainty of the conventional method was 3.4mm on average with maximum values of over 10mm because of imaging artifacts. A novel method based on simple physical measurements was developed to accurately detect the needle-tip position for TRUS-based high-dose-rate prostate brachytherapy. The method demonstrated much improved accuracy and robustness over the conventional method. Copyright © 2011 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Physical aspects of endovascular brachytherapy

International Nuclear Information System (INIS)

Kirisits, C.

2001-11-01

Restenosis is severely limiting the outcome of vascular interventions. In several clinical trials endovascular brachytherapy has shown to reduce the restenosis rate. Local radiotherapy to the injured vessel wall is a promising new type of treatment in order to inhibit a complex wound healing process resulting in cell proliferation and re-obstruction of the treated vessel. Treatment planning has to be based on the dose distribution in the vicinity of the sources used. Source strength was determined in terms of air kerma rate for gamma nuclides (Iridium-192) and absorbed dose to water at reference distance of 2 mm for beta nuclides (Strontium-90/Yttrium-90, Phosphor-32), respectively. Radial dose profiles and the Reference Isodose Length (RIL) were determined using the EGSnrc code and GafChromic film. Good agreement was found between both methods. In order to treat the entire clinical target length, the (RIL) is an essential value during treatment planning. Examples are described for different levels of treatment planing including recommendations for optimal choice and positioning of the radioactive devices inside the artery. IVUS based treatment planning is illustrated with superposition of isodoses on cross-sectional images. A calculation model for radioactive stents is presented in order to determine dose volume histograms in a retrospective analysis. Radiation protection issues for endovascular brachytherapy are discussed in detail. Personal dose for the involved personnel is estimated based on calculations and measurements. Beta ray dosimetry is performed with suitable detectors. In order to estimate the exposure to the patient the dose to organs at risk is calculated and compared to the dose from angiography. There is an additional radiation exposure to patients and personnel caused by endovascular brachytherapy, but the values are much smaller than those caused by diagnostic angiography. (author)

Dosimetric comparison of different dose prescription systems with CT based intracavitary brachytherapy and manual back projection technique to reconstruct the applicator

International Nuclear Information System (INIS)

Oinam, A.S.; Dubey, S.; Kehwar, T.S.; Rout, Sanjaya K.; Patel, F.D.; Sharma, S.C.; Goyal, D.R.; Narayan, P.

2002-01-01

Intracavitary brachytherapy is one of the well-established techniques for the treatment of carcinoma of cervix. The prediction of late effect of normal tissue like rectum and bladder needs the defining of the volume of the bladder and rectum in situ. In the normal planning of intracavitary and interstitial implants, simulated radiograph films are used to reconstruct the applicator geometry and dose points to represent the dose to critical organs. CT based brachytherapy can define such volume instead of defining dose points, which represent the dose to these critical organs

Adjoint current-based approaches to prostate brachytherapy optimization

International Nuclear Information System (INIS)

Roberts, J. A.; Henderson, D. L.

2009-01-01

This paper builds on previous work done at the Univ. of Wisconsin - Madison to employ the adjoint concept of nuclear reactor physics in the so-called greedy heuristic of brachytherapy optimization. Whereas that previous work focused on the adjoint flux, i.e. the importance, this work has included use of the adjoint current to increase the amount of information available in optimizing. Two current-based approaches were developed for 2-D problems, and each was compared to the most recent form of the flux-based methodology. The first method aimed to take a treatment plan from the flux-based greedy heuristic and adjust via application of the current-displacement, or a vector displacement based on a combination of tissue (adjoint) and seed (forward) currents acting as forces on a seed. This method showed promise in improving key urethral and rectal dosimetric quantities. The second method uses the normed current-displacement as the greedy criterion such that seeds are placed in regions of least force. This method, coupled with the dose-update scheme, generated treatment plans with better target irradiation and sparing of the urethra and normal tissues than the flux-based approach. Tables of these parameters are given for both approaches. In summary, these preliminary results indicate adjoint current methods are useful in optimization and further work in 3-D should be performed. (authors)

Trans-abdominal ultrasound (US) and magnetic resonance imaging (MRI) correlation for conformal intracavitary brachytherapy in carcinoma of the uterine cervix

International Nuclear Information System (INIS)

Mahantshetty, Umesh; Khanna, Nehal; Swamidas, Jamema; Engineer, Reena; Thakur, Meenakshi H.; Merchant, Nikhil H.; Deshpande, Deepak D.; Shrivastava, Shyamkishore

2012-01-01

Purpose: Trans-abdominal ultrasonography (US) is capable of determining size, shape, thickness, and diameter of uterus, cervix and disease at cervix or parametria. To assess the potential value of US for image-guided cervical cancer brachytherapy, we compared US-findings relevant for brachytherapy to the corresponding findings obtained from MR imaging. Materials and methods: Twenty patients with biopsy proven cervical cancer undergoing definitive radiotherapy with/without concomitant Cisplatin chemotherapy and suitable for brachytherapy were invited to participate in this study. US and MR were performed in a similar reproducible patient positioning after intracavitary application. US mid-sagittal and axial image at the level of external cervical os was acquired. Reference points D1 to D9 and distances were identified with respect to central tandem and flange, to delineate cervix, central disease, and external surface of the uterus. Results: Thirty-two applications using CT/MR compatible applicators were evaluable. The D1 and D3 reference distances which represent anterior surface had a strong correlation with R = 0.92 and 0.94 (p < 0.01). The D2 and D4 reference distances in contrast, which represent the posterior surface had a moderate (D2) and a strong (D4) correlation with R = 0.63 and 0.82 (p < 0.01). Of all, D2 reference distance showed the least correlation of MR and US. The D5 reference distance representing the fundal thickness from tandem tip had a correlation of 0.98. The reference distances for D6, D7, D8, and D9 had a correlation of 0.94, 0.82, 0.96, and 0.93, respectively. Conclusions: Our study evaluating the use of US, suggests a reasonably strong correlation with MR in delineating uterus, cervix, and central disease for 3D conformal intracavitary brachytherapy planning.

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)

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

Directory of Open Access Journals (Sweden)

Samia de Freitas Brandao

2013-07-01

Full Text Available 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-1.p-1.s, respectively, on the healthy tissue, on the balloon periphery and on the I 1 and I 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-1.p-1.s, respectively on the healthy tissue, on the target tumor and on the I 1 and I 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.

Radioactive sources in brachytherapy:

OpenAIRE

Burger, Janez

2003-01-01

Background. In modern brachytherapy, a greast step forward was made in the 1960s in France with the introduction of new radioactive isotopes and new techniques. These innovations spread rapidly across Europe, though no single dosimetry standard had been set by then. In the new millennium, the advances in brachytherapy are further stimulated by the introduction of 3-D imaging techniques and the latest after loading irradiation equipment that use point sources. The international organiyation IC...

About brachytherapy for the handling of cancer

International Nuclear Information System (INIS)

Campos, Tarcisio P.R.; Silva, Nilton O.; Damaso, Renato S.; Costa, Helder R.; Borges, Paulo H.R.; Mendes, Bruno M.

2000-01-01

The technique of brachytherapy is argued in this article. The 'hardware' and 'necessary software' for the handling are summarily presented. Being the macro-dosimetry an important stage in the radiation therapy procedure, a simplified method of doses evaluation in conventional brachytherapy is presented. In an illustrative form, isodoses of a three-dimensional distribution of linear sources are drawn on a digitalized X-ray picture, exemplifying the handling of breast brachytherapy by sources of iridium

Protocol-based image-guided salvage brachytherapy. Early results in patients with local failure of prostate cancer after radiation therapy

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Lahmer, G.; Lotter, M.; Kreppner, S.; Fietkau, R.; Strnad, V. [University Hospital Erlangen (Germany). Dept. of Radiation Oncology

2013-08-15

Purpose: To assess the overall clinical outcome of protocol-based image-guided salvage pulsed-dose-rate brachytherapy for locally recurrent prostate cancer after radiotherapy failure particularly regarding feasibility and side effects. Patients and methods: Eighteen consecutive patients with locally recurrent prostate cancer (median age, 69 years) were treated during 2005-2011 with interstitial PDR brachytherapy (PDR-BT) as salvage brachytherapy after radiotherapy failure. The treatment schedule was PDR-BT two times with 30 Gy (pulse dose 0.6 Gy/h, 24 h per day) corresponding to a total dose of 60 Gy. Dose volume adaptation was performed with the aim of optimal coverage of the whole prostate (V{sub 100} > 95 %) simultaneously respecting the protocol-based dose volume constraints for the urethra (D{sub 0.1} {sub cc} < 130 %) and the rectum (D{sub 2} {sub cc} < 50-60 %) taking into account the previous radiation therapy. Local relapse after radiotherapy (external beam irradiation, brachytherapy with J-125 seeds or combination) was confirmed mostly via choline-PET and increased PSA levels. The primary endpoint was treatment-related late toxicities - particularly proctitis, anal incontinence, cystitis, urinary incontinence, urinary frequency/urgency, and urinary retention according to the Common Toxicity Criteria. The secondary endpoint was PSA-recurrence-free survival. Results: We registered urinary toxicities only. Grade 2 and grade 3 toxicities were observed in up to 11.1 % (2/18) and 16.7 % (3/18) of patients, respectively. The most frequent late-event grade 3 toxicity was urinary retention in 17 % (3/18) of patients. No late gastrointestinal side effects occurred. The biochemical PSA-recurrence-free survival probability at 3 years was 57.1 %. The overall survival at 3 years was 88.9 %; 22 % (4/18) of patients developed metastases. The median follow-up time for all patients after salvage BT was 21 months (range, 8-77 months). Conclusion: Salvage PDR-brachytherapy

Intravascular ultrasound based dose assessment in endovascular brachytherapy

International Nuclear Information System (INIS)

Catalano, Gianpiero; Tamburini, Vittorio; Colombo, Antonio; Nishida, Takahiro; Parisi, Giovanni; Mazzetta, Chiara; Orecchia, Roberto

2003-01-01

Background: the role of endovascular brachytherapy in restenosis prevention is well documented. Dose is usually prescribed at a fixed distance from the source axis by angiographic quantification of vessel diameter. Recently, intravascular ultrasound (IVUS) was introduced in dose prescription, allowing a better evaluation of the vessel anatomy. This study retrospectively explores the difference between prescription following angiographic vessel sizing and delivered dose calculated with IVUS. Methods and results: Seventeen lesions were studied with IVUS, identifying on irradiated segment, three sections on which measuring minimal and maximal distance from the centre of IVUS catheter to the adventitia; using dedicated software, corresponding doses were calculated. The dose ranged widely, with maximal and minimal values of 71.6 and 4.9 Gy; furthermore, heterogeneity in dose among different sections was observed. In the central section, the maximal dose was 206% of the one prescribed with the QCA model at 2 mm from the source axis, while the minimal dose was 96%. In proximal and distal sections, respective values were 182, 45, 243, and 122%. Conclusions: Our analysis confirmed the dose inhomogeneity delivered with an angiographic fixed-dose prescription strategy. A dose variation was found along the irradiated segment due to the differences in vessel thickness. IVUS emerged as an important tool in endovascular brachytherapy, especially for irregular-shaped vessels

Local experience in cervical cancer imaging: Comparison in tumour assessment between TRUS and MRI.

Science.gov (United States)

Ordeanu, Claudia; Pop, Diana Cristina; Badea, Radu; Csutak, Csaba; Todor, Nicolae; Ordeanu, Calin; Kerekes, Reka; Coza, Ovidiu; Nagy, Viorica; Achimas-Cadariu, Patriciu; Irimie, Alexandru

2015-01-01

The aim of study was to analyze the accuracy of TRUS (transrectal ultrasound) vs. MRI (magnetic resonance imaging) and clinical gynecological examination estimation in the evaluation of tumor dimensions. The patients inclusion criterion included primarily pathologically squamous cell carcinoma, but excluded were patients who had not undergone BT (brachytherapy) and treated with palliative intent. We offer two types of treatment for locally advanced cervical cancer: (a) radiochemotherapy followed by surgery and (b) exclusive radiochemotherapy. Imaging tests follow the presence of tumor and tumor size (width and thickness). Each examination was performed by a different physician who had no knowledge of the others' findings. All patients underwent MRI prior to EBRT (external beam radiation therapy) while 18 of them also at the time of the first brachytherapy application. For the analysis we used the r-Pearson correlation coefficient. In 2013, 26 patients with cervical cancer were included. A total of 44 gynecological examinations were performed, 44 MRIs and 18 TRUSs. For the comparisons prior to EBRT the correlation coefficient between TRUS vs. MRI was r = 0.79 for AP and r = 0.83 for LL, for GYN vs. MRI was r = 0.6 for AP and r = 0.75 for LL. Prior to BT for GYN vs. MRI, r values were 0.60 and 0.63 for AP and LL, respectively; for GYN vs. TRUS, r values were 0.56 and 0.78 for AP and LL, respectively. A high correlation between the three examinations was obtained. As such, TRUS can be considered a suitable method in the evaluation of tumor dimensions.

Implications for dosimetric changes when introducing MR-guided brachytherapy for small volume cervix cancer: a comparison of CT and MR-based treatments in a single centre

International Nuclear Information System (INIS)

Dempsey, Claire; Govindarajulu, Geetha; Sridharan, Swetha; Capp, Anne; O'Brien, Peter

2014-01-01

To evaluate cervix brachytherapy dosimetry with the introduction of magnetic resonance (MR) based treatment planning and volumetric prescriptions and propose a method for plan evaluation in the transition period. The treatment records of 69 patients were reviewed retrospectively. Forty one patients were treated using computed tomography (CT)-based, Point A-based prescriptions and 28 patients were treated using magnetic resonance (MR)-based, volumetric prescriptions. Plans were assessed for dose to Point A and organs at risk (OAR) with additional high-risk clinical target volume (HR-CTV) dose assessment for MR-based brachytherapy plans. ICRU-38 point doses and GEC-ESTRO recommended volumetric doses (D2 cc for OAR and D 100 , D 98 and D 90 for HR-CTV) were also considered. For patients with small HR-CTV sizes, introduction of MR-based volumetric brachytherapy produced a change in dose delivered to Point A and OAR. Point A doses fell by 4.8 Gy (p = 0.0002) and ICRU and D 2cc doses for OAR also reduced (p < 0.01). Mean Point A doses for MR-based brachytherapy treatment plans were closer to those of HR-CTV D 100 for volumes less than 20 cm 3 and HR-CTV D 98 for volumes between 20 and 35 cm 3 , with a significant difference (p < 0.0001) between Point A and HR-CTV D 90 doses in these ranges. In order to maintain brachytherapy dose consistency across varying HR-CTV sizes there must be a relationship between the volume of the HR-CTV and the prescription dose. Rather than adopting a ‘one size fits all’ approach during the transition to volume-based prescriptions, this audit has shown that separating prescription volumes into HR-CTV size categories of less than 20 cm 3 , between 20 and 35 cm 3 , and more than 35 cm 3 the HR-CTV can provide dose uniformity across all volumes and can be directly linked to traditional Point A prescriptions.

Validation of a novel robot-assisted 3DUS system for real-time planning and guidance of breast interstitial HDR brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Poulin, Eric; Beaulieu, Luc, E-mail: Luc.Beaulieu@phy.ulaval.ca [Département de Physique, de Génie Physique et d’optique et Centre de Recherche sur le Cancer de l’Université Laval, Université Laval, Québec, Québec G1V 0A6, Canada and Département de Radio-oncologie et Axe Oncologie du Centre de Recherche du CHU de Québec, CHU de Québec, 11 Côte du Palais, Québec, Québec G1R 2J6 (Canada); Gardi, Lori; Barker, Kevin; Montreuil, Jacques; Fenster, Aaron [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Ontario N6A 5K8 (Canada)

2015-12-15

Purpose: In current clinical practice, there is no integrated 3D ultrasound (3DUS) guidance system clinically available for breast brachytherapy. In this study, the authors present a novel robot-assisted 3DUS system for real-time planning and guidance of breast interstitial high dose rate (HDR) brachytherapy treatment. Methods: For this work, a new computer controlled robotic 3DUS system was built to perform a hybrid motion scan, which is a combination of a 6 cm linear translation with a 30° rotation at both ends. The new 3DUS scanner was designed to fit on a modified Kuske assembly, keeping the current template grid configuration but modifying the frame to allow the mounting of the 3DUS system at several positions. A finer grid was also tested. A user interface was developed to perform image reconstruction, semiautomatic segmentation of the surgical bed as well as catheter reconstruction and tracking. A 3D string phantom was used to validate the geometric accuracy of the reconstruction. The volumetric accuracy of the system was validated with phantoms using magnetic resonance imaging (MRI) and computed tomography (CT) images. In order to accurately determine whether 3DUS can effectively replace CT for treatment planning, the authors have compared the 3DUS catheter reconstruction to the one obtained from CT images. In addition, in agarose-based phantoms, an end-to-end procedure was performed by executing six independent complete procedures with both 14 and 16 catheters, and for both standard and finer Kuske grids. Finally, in phantoms, five end-to-end procedures were performed with the final CT planning for the validation of 3DUS preplanning. Results: The 3DUS acquisition time is approximately 10 s. A paired Student t-test showed that there was no statistical significant difference between known and measured values of string separations in each direction. Both MRI and CT volume measurements were not statistically different from 3DUS volume (Student t-test: p > 0

Anatomy-based inverse optimization in high-dose-rate brachytherapy combined with hypofractionated external beam radiotherapy for localized prostate cancer: Comparison of incidence of acute genitourinary toxicity between anatomy-based inverse optimization and geometric optimization

International Nuclear Information System (INIS)

Akimoto, Tetsuo; Katoh, Hiroyuki; Kitamoto, Yoshizumi; Shirai, Katsuyuki; Shioya, Mariko; Nakano, Takashi

2006-01-01

Purpose: To evaluate the advantages of anatomy-based inverse optimization (IO) in planning high-dose-rate (HDR) brachytherapy. Methods and Materials: A total of 114 patients who received HDR brachytherapy (9 Gy in two fractions) combined with hypofractionated external beam radiotherapy (EBRT) were analyzed. The dose distributions of HDR brachytherapy were optimized using geometric optimization (GO) in 70 patients and by anatomy-based IO in the remaining 44 patients. The correlation between the dose-volume histogram parameters, including the urethral dose and the incidence of acute genitourinary (GU) toxicity, was evaluated. Results: The averaged values of the percentage of volume receiving 80-150% of the prescribed minimal peripheral dose (V 8 -V 15 ) of the urethra generated by anatomy-based IO were significantly lower than the corresponding values generated by GO. Similarly, the averaged values of the minimal dose received by 5-50% of the target volume (D 5 -D 5 ) obtained using anatomy-based IO were significantly lower than those obtained using GO. Regarding acute toxicity, Grade 2 or worse acute GU toxicity developed in 23% of all patients, but was significantly lower in patients for whom anatomy-based IO (16%) was used than in those for whom GO was used (37%), consistent with the reduced urethral dose (p <0.01). Conclusion: The results of this study suggest that anatomy-based IO is superior to GO for dose optimization in HDR brachytherapy for prostate cancer

Present status and future of high-precision image guided adaptive brachytherapy for cervix carcinoma

International Nuclear Information System (INIS)

Poetter, Richard; Kirisits, Christian; Fidarova, Elena F.; Dimopoulos, Johan nes C. A.; Berger, Daniel; Tanderup, Kari; Lindegaard, Jacob C.

2008-01-01

Introduction. Image guided adaptive brachytherapy (IGABT) for cervical cancer, using mainly MRI, is an evolving method, increasingly replacing the 2D approach based on conventional radiography. During the complex 4D chain of this procedure image-assistance is provided for disease assessment, provisional treatment planning ('pre-planning'), applicator placement and reconstruction, as well as for contouring, definitive treatment planning and quality control of dose delivery. With IGABT changes of topography adjacent to the applicator, caused by tumour regression, oedema, organ changes and dilation are identified. Thus, the CTV for IGABT is primarily based on the tumour volume at the time of BT and takes into account both time and spatial domains. IGABT requires systematic concepts for target, OAR, biological modelling, DVH analysis, and dose-volume-adaptation. Methods and Results. This report focuses on the advantages and uncertainties, dose-effect relations and clinical results of the IGABT procedure addressing the current status and future perspectives. Uncertainties during the 4D chain of IGABT are mainly related to target contouring, applicator reconstruction, as well as to inter-fraction, intra-fraction and inter-application variability, as caused by tumour response and organ changes. Different from EBRT where set-up uncertainties are compensated by adding a margin to the CTV, no margins to the lateral and anterior-posterior directions can be used for IGABT. Discussion. By 3D treatment planning for IGABT significant improvement of the DVH parameters is achieved compared to 2D library plans. In small tumours the benefit is primarily obtained by a decrease of dose to nearby OAR while in large tumours the use of supplementary interstitial techniques and optimization may double the target volume that can be treated at a therapeutic dose level. The clinical impact of IGABT could recently be demonstrated by the establishment of some correlations between target- and

TU-AB-201-07: Image Guided Endorectal HDR Brachytherapy Using a Compliant Balloon Applicator

Energy Technology Data Exchange (ETDEWEB)

Cohen, G; Goodman, K [Memorial Sloan Kettering Cancer Center, New York, NY (United States)

2015-06-15

Purpose: High dose rate endorectal brachytherapy is an option to deliver a focal, high-dose radiotherapy to rectal tumors for patients undergoing non-operative management. We investigate a new multichannel, MR compatible applicator with a novel balloon-based design to provide improved treatment geometry. We report on the initial clinical experience using this applicator. Methods: Patients were enrolled on an IRB-approved, dose-escalation protocol evaluating the use of the anorectal (AR-1) applicator (Ancer Medical, Hialeah, FL), a multichannel applicator with two concentric balloons. The inner balloon supports 8 source lumens; the compliant outer balloon expands to separate the normal rectal wall and the source lumens, yet deforms around a firm, exophytic rectal mass, leading to dose escalation to tumor while sparing normal rectum. Under general anesthesia, gold fiducial markers were inserted above and below the tumor, and the AR applicator was placed in the rectum. MRI-based treatment plans were prepared to deliver 15 Gy in 3 weekly fractions to the target volume while sparing healthy rectal tissue, bladder, bowel and anal muscles. Prior to each treatment, CBCT/Fluoroscopy were used to place the applicator in the treatment position and confirm the treatment geometry using rigid registration of the CBCT and planning MRI. After registration of the applicator images, positioning was evaluated based on the match of the gold markers. Results: Highly conformal treatment plans were achieved. MR compatibility of the applicator enabled good tumor visualization. In spite of the non-rigid nature of the applicators and the fact that a new applicator was used at each treatment session, treatment geometry was reproducible to within 2.5 mm. Conclusions: This is the first report on using the AR applicator in patients. Highly conformal plans, confidence in MRI target delineation, in combination with reproducible treatment geometry provide encouraging feedback for continuation with

Nasopharyngeal carcinoma with cranial nerve palsy: The importance of MRI for radiotherapy

International Nuclear Information System (INIS)

Chang, Joseph T.-C.; Lin, C.-Y.; Chen, T.-M.; Kang, C.-J.; Ng, S.-H.; Chen, I.-H.; Wang, H.-M.; Cheng, A.-J.; Liao, C.-T.

2005-01-01

Purpose: To evaluate various prognostic factors and the impact of imaging modalities on tumor control in patients with nasopharyngeal cancer (NPC) with cranial nerve (China) palsy. Material and Methods: Between September 1979 and December 2000, 330 NPC patients with CN palsy received radical radiotherapy (RT) by the conventional opposing technique at Chang Gung Memorial Hospital-Linkou. Imaging methods used varied over that period, and included conventional tomography (Tm) for 47 patients, computerized tomography (CT) for 195 patients, and magnetic resonance image (MRI) for 88 patients. Upper CN (II-VI) palsy was found in 268 patients, lower CN (IX-XII) in 13, and 49 patients had both. The most commonly involved CN were V or VI or both (23%, 12%, and 16%, respectively). All patients had good performance status (World Health Organization <2). The median external RT dose was 70.2 Gy (range, 63-77.5 Gy). Brachytherapy was also given to 156 patients in addition to external RT, delivered by the remote after-loading, high-dose-rate technique. A total of 139 patients received cisplatin-based chemotherapy, in 115 received as neoadjuvant or adjuvant chemotherapy and in 24 concomitant with RT. Recovery from CN palsy occurred in 171 patients during or after radiotherapy. Patients who died without a specific cause identified were regarded as having died with persistent disease. Results: The 3-year, 5-year, and 10-year overall survival was 47.1%, 34.4%, and 22.2%. The 3-year, 5-year, and 10-year disease-specific survival (DSS) rates were 50.4%, 37.8%, and 25.9%. The 5-year DSS for patients staged with MRI, CT, and Tm were 46.9%, 36.7%, and 21.9%, respectively (p = 0.016). The difference between MRI and CT was significant (p = 0.015). The 3-year and 5-year local control rates were 62% and 53%, respectively. The 5-year local control was 68.2% if excluding patients who died without a specific cause. Patients who had an MRI had a significantly better tumor control rate than those

Evaluation of Delivery Costs for External Beam Radiation Therapy and Brachytherapy for Locally Advanced Cervical Cancer Using Time-Driven Activity-Based Costing.

Science.gov (United States)

Bauer-Nilsen, Kristine; Hill, Colin; Trifiletti, Daniel M; Libby, Bruce; Lash, Donna H; Lain, Melody; Christodoulou, Deborah; Hodge, Constance; Showalter, Timothy N

2018-01-01

To evaluate the delivery costs, using time-driven activity-based costing, and reimbursement for definitive radiation therapy for locally advanced cervical cancer. Process maps were created to represent each step of the radiation treatment process and included personnel, equipment, and consumable supplies used to deliver care. Personnel were interviewed to estimate time involved to deliver care. Salary data, equipment purchasing information, and facilities costs were also obtained. We defined the capacity cost rate (CCR) for each resource and then calculated the total cost of patient care according to CCR and time for each resource. Costs were compared with 2016 Medicare reimbursement and relative value units (RVUs). The total cost of radiation therapy for cervical cancer was $12,861.68, with personnel costs constituting 49.8%. Brachytherapy cost $8610.68 (66.9% of total) and consumed 423 minutes of attending radiation oncologist time (80.0% of total). External beam radiation therapy cost $4055.01 (31.5% of total). Personnel costs were higher for brachytherapy than for the sum of simulation and external beam radiation therapy delivery ($4798.73 vs $1404.72). A full radiation therapy course provides radiation oncologists 149.77 RVUs with intensity modulated radiation therapy or 135.90 RVUs with 3-dimensional conformal radiation therapy, with total reimbursement of $23,321.71 and $16,071.90, respectively. Attending time per RVU is approximately 4-fold higher for brachytherapy (5.68 minutes) than 3-dimensional conformal radiation therapy (1.63 minutes) or intensity modulated radiation therapy (1.32 minutes). Time-driven activity-based costing was used to calculate the total cost of definitive radiation therapy for cervical cancer, revealing that brachytherapy delivery and personnel resources constituted the majority of costs. However, current reimbursement policy does not reflect the increased attending physician effort and delivery costs of brachytherapy. We

SU-E-J-239: IMRT Planning of Prostate Cancer for a MRI-Linac Based On MRI Only

Energy Technology Data Exchange (ETDEWEB)

Chen, X; Prior, P; Paulson, E; Lawton, C; Li, X [Medical College of Wisconsin, Milwaukee, WI (United States)

2014-06-01

Purpose: : To investigate dosimetric differences between MRI- and CT-based IMRT planning for prostate cancer, the impact of a magnetic field in a MRI-Linac, and to explore the feasibility of IMRT planning based on MRI alone. Methods: IMRT plans were generated based on CT and MRI images acquired on two representative prostate-cancer patients using clinical dose volume constraints. A research planning system (Monaco, Elekta), which employs a Monte Carlo dose engine and includes a perpendicular magnetic field of 1.5T from an MRI-Linac, was used. Bulk electron density assignments based on organ-specific values from ICRU 46 were used to convert MRI (T2) to pseudo CT. With the same beam configuration as in the original CT plan, 5 additional plans were generated based on CT or MRI, with or without optimization (i.e., just recalculation) and with or without the magnetic field. The plan quality in terms of commonly used dose volume (DV) parameters for all plans was compared. The statistical uncertainty on dose was < 1%. Results: For plans with the same contour set but without re-optimization, the DV parameters were different from those for the original CT plan, mostly less than 5% with a few exceptions. These differences were reduced to mostly less than 3% when the plans were re-optimized. For plans with contours from MRI, the differences in the DV parameters varied depending on the difference in the contours as compared to CT. For the optimized plans with contours from MR, the differences for PTV were less than 3%. Conclusion: The prostate IMRT plans based on MRI-only for a MR-Linac were practically similar as compared to the CT plan under the same beam and optimization configuration if the difference on the structure delineation is excluded, indicating the feasibility of using MRI-only for prostate IMRT.

Patterns of care for brachytherapy in Europe. Results in Spain.

Science.gov (United States)

López Torrecilla, J; Guedea, F; Heeren, G; Nissin, R; Ellison, T; Cottier, B

2006-05-01

In 2003 ESTRO began a project whose primary objective, was to make a map in the European area of infrastructures in technology and personnel for brachytherapy. A survey and a web site were elaborated. The survey was sent to the 76 Spanish Radiation Oncology departments in May 2003. By the end of 2003, 66 (86.8%) services had responded, 40 (71.4%) of which had brachytherapy. The services with brachytherapy treated 73.5% of the total patients, an average of 1,199 patients. The mean number of patients treated with brachytherapy by department was 135.5 and the number of applications was 265 annually. The average number of specialists was 7, 4 of them trained in brachytherapy. The average weekly work load of the radiation oncologists, physicists, and technicians was 22.6 h, 13.8 h and 21.0 h, respectively. The mean time dedicated to each patient by radiation oncologists, physicists and technicians was 9.2 h; 6.19 h; 7.2 h, respectively. The total number of afterloaders was 43 (22 HDR, 18 LDR, 3 PDR). The tumours most frequently treated with brachytherapy were gynaecological (56.24%), breast (14.2%) and prostate (11.7%). High dose rate was used in 47.46% of the patients and low dose rate in 47.24%. Between 1997 and 2002 there was an increase of 50.53% in patients treated with brachytherapy. The survey shows the brachytherapy resources and activity in Spain up to 2003. Increased use of brachytherapy in prostate tumours, prevalence of gynaecology brachytherapy and similar number of treatments with HDR and LDR are demonstrated in the Patterns of Care of Brachytherapy in Europe (PCBE) study in Spain.

B0-correction and k-means clustering for accurate and automatic identification of regions with reduced apparent diffusion coefficient (ADC) in adva nced cervical cancer at the time of brachytherapy

DEFF Research Database (Denmark)

Haack, Søren; Pedersen, Erik Morre; Vinding, Mads Sloth

in dose planning of radiotherapy. This study evaluates the use of k-means clustering for automatic user independent delineation of regions of reduced apparent diffusion coefficient (ADC) and the value of B0-correction of DW-MRI for reduction of geometrical distortions during dose planning of brachytherapy...

The American brachytherapy society survey of brachytherapy practice for carcinoma of the cervix in the United States.

Science.gov (United States)

Nag, S; Orton, C; Young, D; Erickson, B

1999-04-01

The purpose of this study was to survey the brachytherapy practice for cervical cancer in the United States. The Clinical Research Committee of the American Brachytherapy Society (ABS) performed a retrospective survey of individual physicians of the ABS and American Society of Therapeutic Radiologists and Oncologists regarding the details of the brachytherapy techniques they personally used in the treatment of cervical cancer patients for the year 1995. The replies (some of which may have been an estimate only) were tabulated. The scope of this survey did not allow us to verify the data by chart audits. A total of about 3500 questionnaires were mailed out; 521 responses were received. Of these responders, 206 (40%) did not perform any brachytherapy for carcinoma of the cervix in 1995. Of the other 315 responders reporting a total of 4892 patients treated in 1995, 88% used low dose rate (LDR) while 24% used high dose rate (HDR). There was a wide variation in the doses used. For LDR treatments, the median total external beam radiation therapy (EBRT) dose was 45 and 50 Gy and the LDR dose was 42 and 45 Gy for early and advanced cancers, respectively. For HDR treatments, the median EBRT dose was 48 and 50 Gy and the median HDR dose was 29 and 30 Gy for early and advanced cancers, respectively. The median dose per fraction was 6 Gy for a median of five fractions. Interstitial brachytherapy was used as a component of the treatment in 6% of the patients by 21% of responders. Very few responders treated with pulsed or medium dose rates. This retrospective survey showed the current brachytherapy practice pattern in the treatment of cervical cancer in the United States and can serve as a basis for future prospective national brachytherapy data registry. There was wide variation in the practice pattern, emphasizing the urgent need for consensus on these issues. Copyright 1999 Academic Press.

A method to combine three dimensional dose distributions for external beam and brachytherapy radiation treatments for gynecological neoplasms

International Nuclear Information System (INIS)

Narayana, V.; Sahijdak, W.M.; Orton, C.G.

1997-01-01

Purpose: Radiation treatment of gynecological neoplasms, such as cervical carcinoma, usually combines external radiation therapy with one or more intracavitary brachytherapy applications. Although the dose from external beam radiation therapy and brachytherapy can be calculated and displayed in 3D individually, the dose distributions are not combined. At most, combined point doses are calculated for select points using various time-dose models. In this study, we present a methodology to combine external beam and brachytherapy treatments for gynecological neoplasms. Material and Methods: Three dimensional bio-effect treatment planning to obtain complication probability has been outlined. CT scans of the patient's pelvis with the gynecological applicator in place are used to outline normal tissue and tumor volumes. 3D external beam and brachytherapy treatment plans are developed separately and an external beam dose matrix and a brachytherapy dose matrix was calculated. The dose in each voxel was assumed to be homogeneous. The physical dose in each voxel of the dose matrix was then converted into extrapolated response dose (ERD) based on the linear quadratic model that accounts for the dose per fraction, number of fractions, dose rate, and complete or incomplete repair of sublethal damage (time between fractions). The net biological dose delivered was obtained by summing the ERD grids from external beam and brachytherapy since there was complete repair of sublethal damage between external beam and brachytherapy treatments. The normal tissue complication probability and tumor control probability were obtained using the biological dose matrix based on the critical element model. Results: The outlined method of combining external beam and brachytherapy treatments was implemented on gynecological treatments using an applicator for brachytherapy treatments. Conclusion: Implementation of the biological dose calculation that combine different modalities is extremely useful

Patient effective dose from endovascular brachytherapy with 192Ir Sources

International Nuclear Information System (INIS)

Perna, L.; Bianchi, C.; Novario, R.; Nicolini, G.; 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 192 Ir 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 Rando 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 coronary treatment were 2.4x10 -2 mSv.GBq -1 .min -1 for lung, 0.9x10 -2 mSv.GBq -1 .min -1 for oesophagus and 0.48x10 -2 mSv.GBq -1 .min -1 for bone marrow. During brachytherapy of the renal artery, the corresponding normalised doses were 4.2x10 -2 mSv.GBq -1 .min -1 for colon, 7.8x10 -2 mSv.GBq -1 .min -1 for stomach and 1.7x10 -2 mSv.GBq -1 .min -1 for liver. Coronary treatment involved an effective 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. (author)

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.

Fast GPU-based Monte Carlo simulations for LDR prostate brachytherapy

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Bonenfant, Éric; Magnoux, Vincent; Hissoiny, Sami; Ozell, Benoît; Beaulieu, Luc; Després, Philippe

2015-07-01

The aim of this study was to evaluate the potential of bGPUMCD, a Monte Carlo algorithm executed on Graphics Processing Units (GPUs), for fast dose calculations in permanent prostate implant dosimetry. It also aimed to validate a low dose rate brachytherapy source in terms of TG-43 metrics and to use this source to compute dose distributions for permanent prostate implant in very short times. The physics of bGPUMCD was reviewed and extended to include Rayleigh scattering and fluorescence from photoelectric interactions for all materials involved. The radial and anisotropy functions were obtained for the Nucletron SelectSeed in TG-43 conditions. These functions were compared to those found in the MD Anderson Imaging and Radiation Oncology Core brachytherapy source registry which are considered the TG-43 reference values. After appropriate calibration of the source, permanent prostate implant dose distributions were calculated for four patients and compared to an already validated Geant4 algorithm. The radial function calculated from bGPUMCD showed excellent agreement (differences within 1.3%) with TG-43 accepted values. The anisotropy functions at r = 1 cm and r = 4 cm were within 2% of TG-43 values for angles over 17.5°. For permanent prostate implants, Monte Carlo-based dose distributions with a statistical uncertainty of 1% or less for the target volume were obtained in 30 s or less for 1 × 1 × 1 mm3 calculation grids. Dosimetric indices were very similar (within 2.7%) to those obtained with a validated, independent Monte Carlo code (Geant4) performing the calculations for the same cases in a much longer time (tens of minutes to more than a hour). bGPUMCD is a promising code that lets envision the use of Monte Carlo techniques in a clinical environment, with sub-minute execution times on a standard workstation. Future work will explore the use of this code with an inverse planning method to provide a complete Monte Carlo-based planning solution.

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 must...

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...

Multi-atlas-based automatic 3D segmentation for prostate brachytherapy in transrectal ultrasound images

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Nouranian, Saman; Mahdavi, S. Sara; Spadinger, Ingrid; Morris, William J.; Salcudean, S. E.; Abolmaesumi, P.

2013-03-01

One of the commonly used treatment methods for early-stage prostate cancer is brachytherapy. The standard of care for planning this procedure is segmentation of contours from transrectal ultrasound (TRUS) images, which closely follow the prostate boundary. This process is currently performed either manually or using semi-automatic techniques. This paper introduces a fully automatic segmentation algorithm which uses a priori knowledge of contours in a reference data set of TRUS volumes. A non-parametric deformable registration method is employed to transform the atlas prostate contours to a target image coordinates. All atlas images are sorted based on their registration results and the highest ranked registration results are selected for decision fusion. A Simultaneous Truth and Performance Level Estimation algorithm is utilized to fuse labels from registered atlases and produce a segmented target volume. In this experiment, 50 patient TRUS volumes are obtained and a leave-one-out study on TRUS volumes is reported. We also compare our results with a state-of-the-art semi-automatic prostate segmentation method that has been clinically used for planning prostate brachytherapy procedures and we show comparable accuracy and precision within clinically acceptable runtime.

A comparison study on various low energy sources in interstitial prostate brachytherapy.

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Bakhshabadi, Mahdi; Ghorbani, Mahdi; Khosroabadi, Mohsen; Knaup, Courtney; Meigooni, Ali S

2016-02-01

Low energy sources are routinely used in prostate brachytherapy. (125)I is one of the most commonly used sources. Low energy (131)Cs source was introduced recently as a brachytherapy source. The aim of this study is to compare dose distributions of (125)I, (103)Pd, and (131)Cs sources in interstitial brachytherapy of prostate. ProstaSeed (125)I brachytherapy source was simulated using MCNPX Monte Carlo code. Additionally, two hypothetical sources of (103)Pd and (131)Cs were simulated with the same geometry as the ProstaSeed (125)I source, while having their specific emitted gamma spectra. These brachytherapy sources were simulated with distribution of forty-eight seeds in a phantom including prostate. The prostate was considered as a sphere with radius of 1.5 cm. Absolute and relative dose rates were obtained in various distances from the source along the transverse and longitudinal axes inside and outside the tumor. Furthermore, isodose curves were plotted around the sources. Analyzing the initial dose profiles for various sources indicated that with the same time duration and air kerma strength, (131)Cs delivers higher dose to tumor. However, relative dose rate inside the tumor is higher and outside the tumor is lower for the (103)Pd source. The higher initial absolute dose in cGy/(h.U) of (131)Cs brachytherapy source is an advantage of this source over the others. The higher relative dose inside the tumor and lower relative dose outside the tumor for the (103)Pd source are advantages of this later brachytherapy source. Based on the total dose the (125)I source has advantage over the others due to its longer half-life.

Chemotherapy, brachytherapy and surgery of locally evolved uterine cervix carcinomas: prognosis factors of local control and global survival

International Nuclear Information System (INIS)

Laude, C.; Montella, A.; Montbarbon, X.; Malet, C.; Racadot, S.; Pommier, P.; Mathevet, P.; Buenerd, A.

2009-01-01

The protocol used allows an excellent local control of the uterine cervix carcinoma with an acceptable morbidity. To anticipate the presence of a tumor residue can be an evolution in the therapy management after external radiotherapy, particularly in optimized image-guided brachytherapy (MRI and PET)New utero vaginal applicators with parameters implantation allow to realise the dose complement at the distal parameters. These advances make consider an improvement of results in the management of locally evolved uterine cervix carcinomas. (N.C.)

Prostate brachytherapy - discharge

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Implant therapy - prostate cancer - discharge; Radioactive seed placement - discharge ... You had a procedure called brachytherapy to treat prostate cancer. Your treatment lasted 30 minutes or more, ...

Resolving the brachytherapy challenges with government funded hospital.

Science.gov (United States)

Nikam, D S; Jagtap, A S; Vinothraj, R

2016-01-01

The objective of this study is to rationalize the feasibility and cost-effectiveness of high dose rate (HDR) cobalt 60 (Co-60) source versus 192-Iridium (192-Ir) source brachytherapy in government funded hospitals and treatment interruption gap because of exchange of sources. A retrospective study of gynecological cancer patients, treated by radiotherapy with curative intent between April 2005 and September 2012 was conducted. We analyzed the total number of patients treated for external beam radiotherapy (EBRT) and brachytherapy (Intracavitary brachytherapy or cylindrical vaginal source). The dates for 192-Ir sources installation and the last date and first date of brachytherapy procedure before and after source installation respectively were also analyzed and calculated the gap in days for brachytherapy interruptions. The study was analyzed the records of 2005 to September 2012 year where eight 192-Ir sources were installed. The mean gap between treatment interruptions was 123.12 days (range 1-647 days). The Institutional incidence of gynecological cancer where radiotherapy was treatment modality (except ovary) is 34.9 percent. Around 52.25 percent of patients who received EBRT at this institute were referred to outside hospital for brachytherapy because of unavailability of Iridium source. The cost for 5 year duration for single cobalt source is approximately 20-22 lakhs while for 15 Iridium sources is approximately 52-53 lakhs. The combined HDR Co-60 brachytherapy and EBRT provide a useful modality in the treatment of gynecological cancer where radiotherapy is indicated, the treatment interruption because of source exchange is longer and can be minimized by using cobalt source as it is cost-effective and has 5 year working life. Thus, Co-60 source for brachytherapy is a feasible option for government funded hospitals in developing countries.

Adherence to Vaginal Dilation Following High Dose Rate Brachytherapy for Endometrial Cancer

International Nuclear Information System (INIS)

Friedman, Lois C.; Abdallah, Rita; Schluchter, Mark; Panneerselvam, Ashok; Kunos, Charles A.

2011-01-01

Purpose: We report demographic, clinical, and psychosocial factors associated with adherence to vaginal dilation and describe the sexual and marital or nonmarital dyadic functioning of women following high dose rate (HDR) brachytherapy for endometrial cancer. Methods and Materials: We retrospectively evaluated women aged 18 years or older in whom early-stage endometrial (IAgr3-IIB) cancers were treated by HDR intravaginal brachytherapy within the past 3.5 years. Women with or without a sexual partner were eligible. Patients completed questionnaires by mail or by telephone assessing demographic and clinical variables, adherence to vaginal dilation, dyadic satisfaction, sexual functioning, and health beliefs. Results: Seventy-eight of 89 (88%) eligible women with early-stage endometrial cancer treated with HDR brachytherapy completed questionnaires. Only 33% of patients were adherers, based on reporting having used a dilator more than two times per week in the first month following radiation. Nonadherers who reported a perceived change in vaginal dimension following radiation reported that their vaginas were subjectively smaller after brachytherapy (p = 0.013). Adherers reported more worry about their sex lives or lack thereof than nonadherers (p = 0.047). Patients reported considerable sexual dysfunction following completion of HDR brachytherapy. Conclusions: Adherence to recommendations for vaginal dilator use following HDR brachytherapy for endometrial cancer is poor. Interventions designed to educate women about dilator use benefit may increase adherence. Although sexual functioning was compromised, it is likely that this existed before having cancer for many women in our study.

Guidelines for comprehensive quality assurance in brachytherapy

International Nuclear Information System (INIS)

Goldson, A.L.; Nibhanupudy, J.R.

1984-01-01

Brachytherapy treatment techniques can provide significant improvement in local control and overall survival, but only when quality assurance can be guaranteed. To establish brachytherapy quality assurance, basic requirements for three predetermined subdivisions of clinical institutions will be forwarded. These are: (1) centers having minimum requirements to provide brachytherapy, (2) intermediate centers such as regional or community hospitals, and (3) optimal centers such as university hospital and cancer centers. This presentation will highlight personnel needs, equipment requirements, academic activities, clinical experience with these systems and proposed quality assurance guidelines

Caudal epidural anesthesia during intracavitary brachytherapy for cervical cancer

International Nuclear Information System (INIS)

Isoyama-Shirakawa, Yuko; Abe, Madoka; Nakamura, Katsumasa

2015-01-01

It has been suggested that pain control during intracavitary brachytherapy for cervical cancer is insufficient in most hospitals in Japan. Our hospital began using caudal epidural anesthesia during high-dose-rate (HDR) intracavitary brachytherapy in 2011. The purpose of the present study was to retrospectively investigate the effects of caudal epidural anesthesia during HDR intracavitary brachytherapy for cervical cancer patients. Caudal epidural anesthesia for 34 cervical cancer patients was performed during HDR intracavitary brachytherapy between October 2011 and August 2013. We used the patients' self-reported Numeric Rating Scale (NRS) score at the first session of HDR intracavitary brachytherapy as a subjective evaluation of pain. We compared NRS scores of the patients with anesthesia with those of 30 patients who underwent HDR intracavitary brachytherapy without sacral epidural anesthesia at our hospital between May 2010 and August 2011. Caudal epidural anesthesia succeeded in 33 patients (97%), and the NRS score was recorded in 30 patients. The mean NRS score of the anesthesia group was 5.17 ± 2.97, significantly lower than that of the control group's 6.80 ± 2.59 (P = 0.035). The caudal epidural block resulted in no side-effects. Caudal epidural anesthesia is an effective and safe anesthesia option during HDR intracavitary brachytherapy for cervical cancer. (author)

Brachytherapy for cervix cancer: low-dose rate or high-dose rate brachytherapy – a meta-analysis of clinical trials

Directory of Open Access Journals (Sweden)

Stefano Eduardo J

2009-04-01

Full Text Available Abstract Background The literature supporting high-dose rate brachytherapy (HDR in the treatment of cervical carcinoma derives primarily from retrospective series. However, controversy still persists regarding the efficacy and safety of HDR brachytherapy compared to low-dose rate (LDR brachytherapy, in particular, due to inadequate tumor coverage for stage III patients. Whether LDR or HDR brachytherapy produces better results for these patients in terms of survival rate, local control rate and the treatment complications remain controversial. Methods A meta-analysis of RCT was performed comparing LDR to HDR brachytherapy for cervix cancer treated for radiotherapy alone. The MEDLINE, EMBASE, CANCERLIT and Cochrane Library databases, as well as abstracts published in the annual proceedings were systematically searched. We assessed methodological quality for each outcome by grading the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE methodology. We used "recommend" for strong recommendations, and "suggest" for weak recommendations. Results Pooled results from five randomized trials (2,065 patients of HDR brachytherapy in cervix cancer showed no significant increase of mortality (p = 0.52, local recurrence (p = 0.68, or late complications (rectal; p = 0.7, bladder; p = 0.95 or small intestine; p = 0.06 rates as compared to LDR brachytherapy. In the subgroup analysis no difference was observed for overall mortality and local recurrence in patients with clinical stages I, II and III. The quality of evidence was low for mortality and local recurrence in patients with clinical stage I, and moderate for other clinical stages. Conclusion Our meta-analysis shows that there are no differences between HDR and LDR for overall survival, local recurrence and late complications for clinical stages I, II and III. By means of the GRADE system, we recommend the use of HDR for all clinical stages of cervix

Brachytherapy for cervix cancer: low-dose rate or high-dose rate brachytherapy – a meta-analysis of clinical trials

Science.gov (United States)

Viani, Gustavo A; Manta, Gustavo B; Stefano, Eduardo J; de Fendi, Ligia I

2009-01-01

Background The literature supporting high-dose rate brachytherapy (HDR) in the treatment of cervical carcinoma derives primarily from retrospective series. However, controversy still persists regarding the efficacy and safety of HDR brachytherapy compared to low-dose rate (LDR) brachytherapy, in particular, due to inadequate tumor coverage for stage III patients. Whether LDR or HDR brachytherapy produces better results for these patients in terms of survival rate, local control rate and the treatment complications remain controversial. Methods A meta-analysis of RCT was performed comparing LDR to HDR brachytherapy for cervix cancer treated for radiotherapy alone. The MEDLINE, EMBASE, CANCERLIT and Cochrane Library databases, as well as abstracts published in the annual proceedings were systematically searched. We assessed methodological quality for each outcome by grading the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. We used "recommend" for strong recommendations, and "suggest" for weak recommendations. Results Pooled results from five randomized trials (2,065 patients) of HDR brachytherapy in cervix cancer showed no significant increase of mortality (p = 0.52), local recurrence (p = 0.68), or late complications (rectal; p = 0.7, bladder; p = 0.95 or small intestine; p = 0.06) rates as compared to LDR brachytherapy. In the subgroup analysis no difference was observed for overall mortality and local recurrence in patients with clinical stages I, II and III. The quality of evidence was low for mortality and local recurrence in patients with clinical stage I, and moderate for other clinical stages. Conclusion Our meta-analysis shows that there are no differences between HDR and LDR for overall survival, local recurrence and late complications for clinical stages I, II and III. By means of the GRADE system, we recommend the use of HDR for all clinical stages of cervix cancer. PMID:19344527

Iodine-125 seed implantation (permanent brachytherapy) for clinically localized prostate cancer

International Nuclear Information System (INIS)

Ebara, Shin; Katayama, Yoshihisa; Tanimoto, Ryuta

2008-01-01

From January 2004 to March 2007, 308 patients with clinically localized prostate cancer were treated using iodine-125 ( 125 I) seed implantation (permanent brachytherapy) at Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences. We evaluated the treatment's efficacy and morbidity in 300 prostate cancer patients who were followed up for more than 1 month after brachytherapy. Based on the National Comprehensive Cancer Network (NCCN) guidelines, patients with a prostate volume of less than 40 ml in transrectal ultrasound imaging were classified as low or intermediate risk. The median patient age was 67 years (range 50 to 79 years), the median prostate-specific antigen (PSA) value before biopsy was 6.95 ng/ml (range 1.13 to 24.7 ng/ml), and the median prostate volume was 24.33 ml (range 9.3 to 41.76 ml). The median follow-up was 18 months (range 1 to 36 months) and the PSA levels decreased in almost all patients after brachytherapy. Although 194 of 300 patients (64.7%) complained of difficulty in urination, pollakisuria/urgency, miction pain, and/or urinary incontinence, all of which might be associated with radiation prostatitis during the first month after brachytherapy, these symptoms gradually improved. 125 I seed implantation brachytherapy is safe and effective for localized prostate cancer within short-term follow up. (author)

Current status of brachytherapy in Korea: a national survey of radiation oncologists.

Science.gov (United States)

Kim, Haeyoung; Kim, Joo Young; Kim, Juree; Park, Won; Kim, Young Seok; Kim, Hak Jae; Kim, Yong Bae

2016-07-01

The aim of the present study was to acquire information on brachytherapy resources in Korea through a national survey of radiation oncologists. Between October 2014 and January 2015, a questionnaire on the current status of brachytherapy was distributed to all 86 radiation oncology departments in Korea. The questionnaire was divided into sections querying general information on human resources, brachytherapy equipment, and suggestions for future directions of brachytherapy policy in Korea. The response rate of the survey was 88.3%. The average number of radiation oncologists per center was 2.3. At the time of survey, 28 centers (36.8%) provided brachytherapy to patients. Among the 28 brachytherapy centers, 15 (53.5%) were located in in the capital Seoul and its surrounding metropolitan areas. All brachytherapy centers had a high-dose rate system using (192)Ir (26 centers) or (60)Co (two centers). Among the 26 centers using (192)Ir sources, 11 treated fewer than 40 patients per year. In the two centers using (60)Co sources, the number of patients per year was 16 and 120, respectively. The most frequently cited difficulties in performing brachytherapy were cost related. A total of 21 centers had a plan to sustain the current brachytherapy system, and four centers noted plans to upgrade their brachytherapy system. Two centers stated that they were considering discontinuation of brachytherapy due to cost burdens of radioisotope source replacement. The present study illustrated the current status of brachytherapy in Korea. Financial difficulties were the major barriers to the practice of brachytherapy.

TU-F-BRF-02: MR-US Prostate Registration Using Patient-Specific Tissue Elasticity Property Prior for MR-Targeted, TRUS-Guided HDR Brachytherapy

International Nuclear Information System (INIS)

Yang, X; Rossi, P; Ogunleye, T; Jani, A; Curran, W; Liu, T

2014-01-01

Purpose: High-dose-rate (HDR) brachytherapy has become a popular treatment modality for prostate cancer. Conventional transrectal ultrasound (TRUS)-guided prostate HDR brachytherapy could benefit significantly from MR-targeted, TRUS-guided procedure where the tumor locations, acquired from the multiparametric MRI, are incorporated into the treatment planning. In order to enable this integration, we have developed a MR-TRUS registration with a patient-specific biomechanical elasticity prior. Methods: The proposed method used a biomechanical elasticity prior to guide the prostate volumetric B-spline deformation in the MRI and TRUS registration. The patient-specific biomechanical elasticity prior was generated using ultrasound elastography, where two 3D TRUS prostate images were acquired under different probe-induced pressures during the HDR procedure, which takes 2-4 minutes. These two 3D TRUS images were used to calculate the local displacement (elasticity map) of two prostate volumes. The B-spline transformation was calculated by minimizing the Euclidean distance between the normalized attribute vectors of the prostate surface landmarks on the MR and TRUS. This technique was evaluated through two studies: a prostate-phantom study and a pilot study with 5 patients undergoing prostate HDR treatment. The accuracy of our approach was assessed through the locations of several landmarks in the post-registration and TRUS images; our registration results were compared with the surface-based method. Results: For the phantom study, the mean landmark displacement of the proposed method was 1.29±0.11 mm. For the 5 patients, the mean landmark displacement of the surface-based method was 3.25±0.51 mm; our method, 1.71±0.25 mm. Therefore, our proposed method of prostate registration outperformed the surfaced-based registration significantly. Conclusion: We have developed a novel MR-TRUS prostate registration approach based on patient-specific biomechanical elasticity prior

Race and Survival Following Brachytherapy-Based Treatment for Men With Localized or Locally Advanced Adenocarcinoma of the Prostate

International Nuclear Information System (INIS)

Winkfield, Karen M.; Chen Minghui; Dosoretz, Daniel E.; Salenius, Sharon A.; Katin, Michael; Ross, Rudi; D’Amico, Anthony V.

2011-01-01

Purpose: We investigated whether race was associated with risk of death following brachytherapy-based treatment for localized prostate cancer, adjusting for age, cardiovascular comorbidity, treatment, and established prostate cancer prognostic factors. Methods: The study cohort was composed of 5,360 men with clinical stage T1-3N0M0 prostate cancer who underwent brachytherapy-based treatment at 20 centers within the 21st Century Oncology consortium. Cox regression multivariable analysis was used to evaluate the risk of death in African-American and Hispanic men compared to that in Caucasian men, adjusting for age, pretreatment prostate-specific antigen (PSA) level, Gleason score, clinical T stage, year and type of treatment, median income, and cardiovascular comorbidities. Results: After a median follow-up of 3 years, there were 673 deaths. African-American and Hispanic races were significantly associated with an increased risk of all-cause mortality (ACM) (adjusted hazard ratio, 1.77 and 1.79; 95% confidence intervals, 1.3–2.5 and 1.2–2.7; p < 0.001 and p = 0.005, respectively). Other factors significantly associated with an increased risk of death included age (p < 0.001), Gleason score of 8 to 10 (p = 0.04), year of brachytherapy (p < 0.001), and history of myocardial infarction treated with stent or coronary artery bypass graft (p < 0.001). Conclusions: After adjustment for prostate cancer prognostic factors, age, income level, and revascularized cardiovascular comorbidities, African-American and Hispanic races were associated with higher ACM in men with prostate cancer. Additional causative factors need to be identified.

Comparison of CT-based volumetric dosimetry with traditional prescription points in the treatment of cervical cancer with PDR brachytherapy

International Nuclear Information System (INIS)

Lowrey, Nicola; Nilsson, Sanna; Moutrie, Zoe; Chan, Philip; Cheuk, Robyn

2015-01-01

The traditional use of two-dimensional geometric prescription points in intracavitary brachytherapy planning for locally advanced cervical cancer is increasingly being replaced by three-dimensional (3D) planning. This study aimed to directly compare the two planning methods to validate that CT planning provides superior dosimetry for both tumour and organs at risk (OARs) in our department. The CT planning data of 10 patients with locally advanced cervical cancer was audited. For each CT dataset, two new brachytherapy plans were created, comparing the dosimetry of conventional American Brachytherapy Society points and 3D-optimised volumes created for the high-risk clinical target volume (HR CTV) and OARs. Total biologically equivalent doses for these structures were calculated using the modified EQD2 formula and comparative dose-volume histogram (DVH) analysis performed. DVH analysis revealed that for the 3D-optimised plans, the prescription aim of D90 ≥ 100% was achieved for the HR CTV in all 10 patients. However, when prescribing to point A, only 50% of the plans achieved the minimum required dose to the HR CTV. Rectal and bladder dose constraints were met for all 3D-optimised plans but exceeded in two and one of the conventional plans, respectively. This study confirms that the regionally relevant practice of CT-based 3D-optimised planning results in improved tumour dose coverage compared with traditional points-based planning methods and also improves dose to the rectum and bladder.

Computed-tomography-guided high-dose-rate brachytherapy (CT-HDRBT) ablation of metastases adjacent to the liver hilum

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Collettini, Federico, E-mail: federico.collettini@charite.de [Department of Radiology, Charité Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin (Germany); Department of Radiation Oncology, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Singh, Anju [Department of Medical Oncology, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Schnapauff, Dirk [Department of Radiology, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Department of Radiation Oncology, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Powerski, Maciej Janusz [Charité – Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin (Germany); Department of Radiation Oncology, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); and others

2013-10-01

Purpose: To evaluate technical feasibility and clinical outcome of computed tomography-guided high-dose-rate-brachytherapy (CT-HDRBT) ablation of metastases adjacent to the liver hilum. Materials and methods: Between November 2007 and May 2012, 32 consecutive patients with 34 metastases adjacent to the liver hilum (common bile duct or hepatic bifurcation ≤5 mm distance) were treated with CT-HDRBT. Treatment was performed by CT-guided applicator placement and high-dose-rate brachytherapy with an iridium-192 source. MRI follow-up was performed 6 weeks and every 3 months post intervention. The primary endpoint was local tumor control (LTC); secondary endpoints included time to progression (TTP) and overall survival (OS). Results: Patients were available for MRI evaluation for a mean follow-up time of 18.75 months (range: 3–56 months). Mean tumor diameter was 4.3 cm (range: 1.3–10.7 cm). One major complication was observed. Four (11.8%) local recurrences were observed after a local tumor control of 5, 8, 9 and 10 months, respectively. Twenty-two patients (68.75%) experienced a systemic tumor progression during the follow up period. Mean TTP was 12.9 months (range: 2–56 months). Nine patients died during the follow-up period. Median OS was 20.24 months. Conclusion: Minimally invasive CT-HDRBT is a safe and effective option also for unresectable liver metastases adjacent to the liver hilum that would have been untreatable by thermal ablation.

American Brachytherapy Society recommendations for reporting morbidity after prostate brachytherapy

International Nuclear Information System (INIS)

Nag, Subir; Ellis, Rodney J.; Merrick, Gregory S.; Bahnson, Robert; Wallner, Kent; Stock, Richard

2002-01-01

Purpose: To standardize the reporting of brachytherapy-related prostate morbidity to guide ongoing clinical practice and future investigations. Methods: Members of the American Brachytherapy Society (ABS) with expertise in prostate brachytherapy performed a literature review and, guided by their clinical experience, formulated specific recommendations for reporting on morbidity related to prostate brachytherapy. Results: The ABS recommends using validated, patient-administered health-related quality-of-life instruments for the determination of baseline and follow-up data regarding bowel, urinary, and sexual function. Both actuarial and crude incidences should be reported, along with the temporal resolution of specific complications, and correlated with the doses to the normal tissues. The International Prostate Symptom Score is recommended to assess urinary morbidity, and any dysuria, gross hematuria, urinary retention, incontinence, or medication use should be quantified. Likewise, the ''Sexual Health Inventory for Men,'' which includes the specific erectile questions of the International Index of Erectile Function, is the preferred instrument for reporting sexual function, and the loss of sexual desire, incidence of hematospermia, painful orgasm (orgasmalgia), altered orgasm intensity, decreased ejaculatory volume, use of erectile aids, and use of hormones for androgen deprivation should be quantified. The ABS recommends adoption of the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer acute and late radiation morbidity scoring scheme for reporting rectal morbidity and noting the incidence of rectal steroid, laser, or antidiarrheal use. Conclusion: It is important to focus on health-related quality-of-life issues in the treatment of prostate cancer, because the control rates are very similar between appropriate treatment modalities. The ABS recommends using the International Prostate Symptom Score, International Index of

Endovascular brachytherapy prevents restenosis after femoropopliteal angioplasty: results of the Vienna-3 randomised multicenter study

International Nuclear Information System (INIS)

Pokrajac, Boris; Poetter, Richard; Wolfram, Roswitha M.; Budinsky, Alexandra C.; Kirisits, Christian; Lileg, Brigitte; Mendel, Helmuth; Sabeti, Schila; Schmid, Rainer; Minar, Erich

2005-01-01

Background and purpose: The aim of the trial was to investigate the effect of Iridium-192 gamma endovascular brachytherapy on reduction of restenosis after femoropopliteal angioplasty. Patients and methods: Between Oct, 1998 and Jul, 2001 a total of 134 patients have been randomized after successful angioplasty to brachytherapy or sham irradiation in a prospective, randomized, multicenter, double blind controlled trial. Patients with de novo lesion of at least 5 cm or recurrent lesion of any length after prior angioplasty have been enrolled. Brachytherapy was performed with 7 F centering catheter. Mean lesion length was 9.1 cm (1.5-25 cm) and mean intervention length 13.6 cm (4-27.5 cm) in brachytherapy cohort. Results: In placebo cohort mean lesion length was 10.3 cm (2-25 cm) and mean intervention length 14.1 cm (2-29 cm). A dose of 18 Gy was prescribed 2 mm from the surface of centering balloons. Analyzed (based on angiography) on intention to treat basis the binary restenosis rate at 12 months was 41.7% (28/67) in brachytherapy cohort and 67.1% (45/67) in placebo cohort (χ 2 test, P 30% residual stenosis after angioplasty) have been 23.4% in the brachytherapy and 53.3% in the placebo group (P<0.05), respectively. The cumulative patency rates after 24 months on intention to treat analysis were 54% in the brachytherapy and 27% in the placebo group (P<0.005). Corresponding data for as treated analysis were 77% in the brachytherapy and 39% in the placebo group (P<0.001). Late thrombosis was not seen. Conclusions: Significant reduction of restenosis rate was obtained with endovascular gamma brachytherapy after femoropopliteal angioplasty

A new afterloading applicator for primary brachytherapy of endometrial cancer

International Nuclear Information System (INIS)

Bauer, M.; Schulz-Wendtland, R.

1993-01-01

The authors describe and have used a new afterloading applicator in six patients for primary radiation therapy of endometrial cancer. The first introduction of the applicator was done under general anaesthesia. Dilating the cervical canal to Heger 9 made insertion easier. Prior to application it is advisable to probe the lumen of the uterine cavity with a tube or curette to estimate how far the applicator must be spread open. For brachytherapy it is advantageous to remove necrotic tumour portions. This requires experienced hands to avoid perforation of the uterus. The new afterloading applicator is easy to use, and permits direct contact between the six tubes and the tumour. In conjunction with careful planning with the help of MRI, it provides an optimal system for the treatment of endometrial cancer. (Author)

Sexual function after permanent prostate brachytherapy

International Nuclear Information System (INIS)

Galbreath, R.W.; Merrick, G.S.; Butler, W.M.; Stipetich, R.L.; Abel, L.J.; Lief, J.H.

2001-01-01

Purpose: To determine the incidence of potency preservation following permanent prostate brachytherapy and to evaluate the effect of multiple clinical and treatment parameters on penile erectile function. Materials and Methods: 425 patients underwent permanent prostate brachytherapy from April 1995 to October 1999. 209 patients who were potent prior to brachytherapy and currently not receiving hormonal manipulation were mailed an International Index of Erectile Function (IIEF) questionnaire with a pre-addressed stamped envelope. 180 patients completed and returned the questionnaire. Median patient follow-up was 39 months (range 18-74 months). Pre-implant erectile function was assigned using a three-tiered scoring system (2 = erections always or nearly always sufficient for vaginal penetration; 1 = erections sufficient for vaginal penetration but considered suboptimal; 0 = the inability to obtain erections and/or erections inadequate for vaginal penetration). Post-implant potency was defined as an IIEF score >11. Clinical parameters evaluated for sexual function included patient age, clinical T stage, elapsed time since implantation, hypertension, diabetes mellitus, and tobacco consumption. Evaluated treatment parameters included the utilization of neoadjuvant hormonal manipulation and the choice of isotope. The efficacy of sildenafil citrate in brachytherapy induced erectile dysfunction (ED) was also evaluated. Results: A pre-treatment erectile function score of 2 and 1 were assigned to 126 and 54 patients respectively. With 6 year follow up, 39% of patients maintained potency following prostate brachytherapy with a plateau on the curve. Post-implant preservation of potency (IIEF>11) correlated with pre-implant erectile function (50% versus 14% for pre-implant scores of 2 and 1 respectively, p≤0.0001), patient age (56%, 38%, and 23% for patients <60 years of age, 60-69 years of age, and ≥70 years of age respectively, p=0.012) and a history of diabetes mellitus

High dose rate brachytherapy for superficial cancer of the esophagus

International Nuclear Information System (INIS)

Maingon, Philippe; D'Hombres, Anne; Truc, Gilles; Barillot, Isabelle; Michiels, Christophe; Bedenne, Laurent; Horiot, Jean Claude

2000-01-01

Purpose: We analyzed our experience with external radiotherapy, combined modality treatment, or HDR brachytherapy alone to limited esophageal cancers. Methods and Materials: From 1991 to 1996, 25 patients with limited superficial esophagus carcinomas were treated by high dose rate brachytherapy. The mean age was 63 years (43-86 years). Five patients showed superficial local recurrence after external radiotherapy. Eleven patients without invasion of the basal membrane were staged as Tis. Fourteen patients with tumors involving the submucosa without spreading to the muscle were staged as T1. Treatment consisted of HDR brachytherapy alone in 13 patients, external radiotherapy and brachytherapy in 8 cases, and concomitant chemo- and radiotherapy in 4 cases. External beam radiation was administered to a total dose of 50 Gy using 2 Gy daily fractions in 5 weeks. In cases of HDR brachytherapy alone (13 patients), 6 applications were performed once a week. Results: The mean follow-up is 31 months (range 24-96 months). Twelve patients received 2 applications and 13 patients received 6 applications. Twelve patients experienced a failure (48%), 11/12 located in the esophagus, all of them in the treated volume. One patient presented an isolated distant metastasis. In the patients treated for superficial recurrence, 4/5 were locally controlled (80%) by brachytherapy alone. After brachytherapy alone, 8/13 patients were controlled (61%). The mean disease-free survival is 14 months (1-36 months). Overall survival is 76% at 1 year, 37% at 2 years, and 14% at 3 years. Overall survival for Tis patients is 24% vs. 20% for T1 (p 0.83). Overall survival for patients treated by HDR brachytherapy alone is 43%. One patient presented with a fistula with local failure after external radiotherapy and brachytherapy. Four stenosis were registered, two were diagnosed on barium swallowing without symptoms, and two required dilatations. Conclusion: High dose rate brachytherapy permits the treating

Long duration mild temperature hyperthermia and brachytherapy.

Science.gov (United States)

Armour, E P; Raaphorst, G P

2004-03-01

Combining long duration mild temperature hyperthermia (LDMH) and low dose-rate (LDR) brachytherapy to enhance therapeutic killing of cancer cells was proposed many years ago. The cellular and tumour research that supports this hypothesis is presented in this review. Research describing LDMH interaction with pulsed brachytherapy and high dose-rate brachytherapy using clinically relevant parameters are compared with LDMH/LDR brachytherapy. The mechanism by which LDMH sensitizes LDR has been established as the inhibition of sublethal damage repair. The molecular mechanisms have been shown to involve DNA repair enzymes, but the exact nature of these processes is still under investigation. The relative differences between LDMH interactions with human and rodent cells are presented to help in the understanding of possible roles of LDMH in clinical application. The role of LDMH in modifying tumour blood flow and its possible role in LDR sensitization of tumours is also presented. The positive aspects of LDMH-brachytherapy for clinical application are sixfold; (1) the thermal goals (temperature, time and volume) are achievable with currently available technology, (2) the hyperthermia by itself has no detectable toxic effects, (3) thermotolerance appears to play a minor if any role in radiation sensitization, (4) TER of around 2 can be expected, (5) hypoxic fraction may be decreased due to blood flow modification and (6) simultaneous chemotherapy may also be sensitized. Combined LDMH and brachytherapy is a cancer therapy that has established biological rationale and sufficient technical and clinical advancements to be appropriately applied. This modality is ripe for clinical testing.

SU-E-J-207: Effect of Pulse Sequence Parameters On Geometric Distortions Induced by a Titanium Brachytherapy Applicator

International Nuclear Information System (INIS)

Shea, S; Diak, A; Surucu, M; Harkenrider, M; Yacoub, J; Roeske, J; Small, W

2015-01-01

Purpose: To investigate the effect of readout bandwidth and voxel size on the appearance of distortion artifacts caused by a titanium brachytherapy applicator. Methods: An acrylic phantom was constructed to rigidly hold a MR conditional, titanium Fletcher-Suit-Delclos-style applicator set (Varian Medical Systems) for imaging on CT (Philips Brilliance) and 1.5T MRI (Siemens Magnetom Aera). Several variants of MRI parameters were tried for 2D T2-weighted turbo spin echo imaging in comparison against the standard clinical protocol with the criteria to keep relative SNR loss less than 20% and imaging time as short as possible. Two 3D sequences were also used for comparison with similar parameters. The applicator tandem was segmented on axial CT images (0.4×0.4×1.5mm 3 resolution) and the CT images were registered to the 3D MR images in Eclipse (Varian). The applicator volume was then overlaid on all MRI sets in 3D-Slicer and distances were measured from the tandem tip to the MRI artifact edge in right/left/superior and anterior/posterior/superior directions from coronal and sagittal 2D acquisitions, respectively, or 3D data reformats. Artifact regions were also manually contoured in coronal/sagittal orientations for area measurements. Results: As would be expected, reductions in voxel size and increases in readout bandwidth reduced artifact size (average max artifact length decreased by 0.95 mm and average max area decrease by 0.27 cm 2 ). Interestingly, bandwidth increases yielded reductions in area (0.19 cm 2 ) and in distance measurements (1 mm) even with voxel increases, as compared to a standard protocol. This could be useful when high performance protocols are not feasible due to long imaging times. Conclusion: We have characterized artifacts caused by cervical brachytherapy applicator across multiple sequence parameters at 1.5T. Future work will focus on finalizing an optimal protocol that balances artifact reduction with imaging time and then testing this new

Brachytherapy in the treatment of cervical cancer: a review

Directory of Open Access Journals (Sweden)

Banerjee R

2014-05-01

Full Text Available Robyn Banerjee,1 Mitchell Kamrava21Department of Radiation Oncology, Tom Baker Cancer Centre, Calgary, Alberta, Canada; 2Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA, USAAbstract: Dramatic advances have been made in brachytherapy for cervical cancer. Radiation treatment planning has evolved from two-dimensional to three-dimensional, incorporating magnetic resonance imaging and/or computed tomography into the treatment paradigm. This allows for better delineation and coverage of the tumor, as well as improved avoidance of surrounding organs. Consequently, advanced brachytherapy can achieve very high rates of local control with a reduction in morbidity, compared with historic approaches. This review provides an overview of state-of-the-art gynecologic brachytherapy, with a focus on recent advances and their implications for women with cervical cancer.Keywords: cervical cancer, brachytherapy, image-guided brachytherapy

Photon energy-fluence correction factor in low energy brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Antunes, Paula C.G.; Yoriyaz, Hélio [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Vijande, Javier; Giménez-Alventosa, Vicent; Ballester, Facundo, E-mail: pacrisguian@gmail.com [Department of Atomic, Molecular, and Nuclear Physics and Instituto de Física Corpuscular (UV-CSIC), University of Valencia (Spain)

2017-07-01

The AAPM TG-43 brachytherapy dosimetry formalism has become a standard for brachytherapy dosimetry worldwide; it implicitly assumes that charged-particle equilibrium (CPE) exists for the determination of absorbed dose to water at different locations. At the time of relating dose to tissue and dose to water, or vice versa, it is usually assumed that the photon fluence in water and in tissues are practically identical, so that the absorbed dose in the two media can be related by their ratio of mass energy-absorption coefficients. The purpose of this work is to study the influence of photon energy-fluence in different media and to evaluate a proposal for energy-fluence correction factors for the conversion between dose-to-tissue (D{sub tis}) and dose-to-water (D{sub w}). State-of-the art Monte Carlo (MC) calculations are used to score photon fluence differential in energy in water and in various human tissues (muscle, adipose and bone) in two different codes, MCNP and PENELOPE, which in all cases include a realistic modeling of the {sup 125}I low-energy brachytherapy seed in order to benchmark the formalism proposed. A correction is introduced that is based on the ratio of the water-to-tissue photon energy-fluences using the large-cavity theory. In this work, an efficient way to correlate absorbed dose to water and absorbed dose to tissue in brachytherapy calculations at clinically relevant distances for low-energy photon emitting seed is proposed. The energy-fluence based corrections given in this work are able to correlate absorbed dose to tissue and absorbed dose to water with an accuracy better than 0.5% in the most critical cases. (author)

Photon energy-fluence correction factor in low energy brachytherapy

International Nuclear Information System (INIS)

Antunes, Paula C.G.; Yoriyaz, Hélio; Vijande, Javier; Giménez-Alventosa, Vicent; Ballester, Facundo

2017-01-01

The AAPM TG-43 brachytherapy dosimetry formalism has become a standard for brachytherapy dosimetry worldwide; it implicitly assumes that charged-particle equilibrium (CPE) exists for the determination of absorbed dose to water at different locations. At the time of relating dose to tissue and dose to water, or vice versa, it is usually assumed that the photon fluence in water and in tissues are practically identical, so that the absorbed dose in the two media can be related by their ratio of mass energy-absorption coefficients. The purpose of this work is to study the influence of photon energy-fluence in different media and to evaluate a proposal for energy-fluence correction factors for the conversion between dose-to-tissue (D tis ) and dose-to-water (D w ). State-of-the art Monte Carlo (MC) calculations are used to score photon fluence differential in energy in water and in various human tissues (muscle, adipose and bone) in two different codes, MCNP and PENELOPE, which in all cases include a realistic modeling of the 125 I low-energy brachytherapy seed in order to benchmark the formalism proposed. A correction is introduced that is based on the ratio of the water-to-tissue photon energy-fluences using the large-cavity theory. In this work, an efficient way to correlate absorbed dose to water and absorbed dose to tissue in brachytherapy calculations at clinically relevant distances for low-energy photon emitting seed is proposed. The energy-fluence based corrections given in this work are able to correlate absorbed dose to tissue and absorbed dose to water with an accuracy better than 0.5% in the most critical cases. (author)

A comparison study on various low energy sources in interstitial prostate brachytherapy

Directory of Open Access Journals (Sweden)

Mahdi Bakhshabadi

2016-02-01

Full Text Available Purpose: Low energy sources are routinely used in prostate brachytherapy. 125 I is one of the most commonly used sources. Low energy 131 Cs source was introduced recently as a brachytherapy source. The aim of this study is to compare dose distributions of 125 I, 103 Pd, and 131 Cs sources in interstitial brachytherapy of prostate. Material and methods: ProstaSeed 125 I brachytherapy source was simulated using MCNPX Monte Carlo code. Additionally, two hypothetical sources of 103 Pd and 131 Cs were simulated with the same geometry as the ProstaSeed 125 I source, while having their specific emitted gamma spectra. These brachytherapy sources were simulated with distribution of forty-eight seeds in a phantom including prostate. The prostate was considered as a sphere with radius of 1.5 cm. Absolute and relative dose rates were obtained in various distances from the source along the transverse and longitudinal axes inside and outside the tumor. Furthermore, isodose curves were plotted around the sources. Results : Analyzing the initial dose profiles for various sources indicated that with the same time duration and air kerma strength, 131 Cs delivers higher dose to tumor. However, relative dose rate inside the tumor is higher and outside the tumor is lower for the 103 Pd source. Conclusions : The higher initial absolute dose in cGy/(h.U of 131 Cs brachytherapy source is an advantage of this source over the others. The higher relative dose inside the tumor and lower relative dose outside the tumor for the 103 Pd source are advantages of this later brachytherapy source. Based on the total dose the 125 I source has advantage over the others due to its longer half-life.

Radiation Exposure Reduction to Brachytherapy Staff By Using Remote Afterloading

International Nuclear Information System (INIS)

Attalla, E.M.

2005-01-01

The radiation exposures to the personnel staff from patients with brachytherapy implants in a brachytherapy service were reviewed. Exposures to the brachytherapy personnel, as determined by Thermoluminescence Dosimeter (TLD) monitors, indicates a four-fold reduction in exposures after the implantation of the use of remote afterloading devices. Quarterly TLD monitor data for seven quarters prior to the use of remote afterloading devices demonstrate an average projected annual dose equivalent to the brachytherapy staff of 2543 Μ Sv. After the implantation of the remote afterloading devices, the quarterly TLD monitor data indicate an average dose equivalent per person of 153 Μ Sv. This is 76% reduction in exposure to brachytherapy personnel with the use of these devices

Calculation of integrated biological response in brachytherapy

International Nuclear Information System (INIS)

Dale, Roger G.; Coles, Ian P.; Deehan, Charles; O'Donoghue, Joseph A.

1997-01-01

Purpose: To present analytical methods for calculating or estimating the integrated biological response in brachytherapy applications, and which allow for the presence of dose gradients. Methods and Materials: The approach uses linear-quadratic (LQ) formulations to identify an equivalent biologically effective dose (BED eq ) which, if applied to a specified tissue volume, would produce the same biological effect as that achieved by a given brachytherapy application. For simple geometrical cases, BED multiplying factors have been derived which allow the equivalent BED for tumors to be estimated from a single BED value calculated at a dose reference point. For more complex brachytherapy applications a voxel-by-voxel determination of the equivalent BED will be more accurate. Equations are derived which when incorporated into brachytherapy software would facilitate such a process. Results: At both high and low dose rates, the BEDs calculated at the dose reference point are shown to be lower than the true values by an amount which depends primarily on the magnitude of the prescribed dose; the BED multiplying factors are higher for smaller prescribed doses. The multiplying factors are less dependent on the assumed radiobiological parameters. In most clinical applications involving multiple sources, particularly those in multiplanar arrays, the multiplying factors are likely to be smaller than those derived here for single sources. The overall suggestion is that the radiobiological consequences of dose gradients in well-designed brachytherapy treatments, although important, may be less significant than is sometimes supposed. The modeling exercise also demonstrates that the integrated biological effect associated with fractionated high-dose-rate (FHDR) brachytherapy will usually be different from that for an 'equivalent' continuous low-dose-rate (CLDR) regime. For practical FHDR regimes involving relatively small numbers of fractions, the integrated biological effect to

Biology of dose rate in brachytherapy

International Nuclear Information System (INIS)

Brenner, David J.

1995-01-01

Purpose: This course is designed for practitioners and beginners in brachytherapy. The aim is to review biological principles underlying brachytherapy, to understand why current treatment regimes are the way they are, and to discuss what the future may hold in store. Brachytherapy has a long history. It was suggested as long ago as 1903 by Alexander Graham Bell, and the optimal application of this technique has been a subject of debate ever since. 'Brachy' means 'short', and the essential features of conventional brachytherapy are: positioning of the source a short distance from, or in, the tumor, allowing good dose distributions; short overall treatment times, to counter tumor repopulation; low dose rate, enabling a good therapeutic advantage between tumor control and damage to late-responding tissue. The advantages of good dose distributions speak for themselves; in some situations, as we shall see, computer-based dose optimization can be used to improve them still further. The advantages of short overall times stem from the fact that accelerated repopulation of the tumor typically begins a few weeks after the start of a radiation treatment. If all the radiation can be crammed in before that time, the risks of tumor repopulation can be considerably reduced. In fact even external-beam radiotherapy is moving in this direction, with the use of highly accelerated protocols. The advantages of low dose rate stem from the differential response to fractionation of early- and late-responding tissues. Essentially, lowering the dose rate spares late-responding tissue more than it does early-responding tissue such as tumors. We shall also discuss some recent innovations in the context of the general principles that have been outlined. For example, High dose rate brachytherapy, particularly for the uterine cervix: Does it work? If so, when and why? Use of Ir-192 sources, with a half life of 70 days: Should corrections be made for changing biological effectiveness as the dose

MRI-Based Nonrigid Motion Correction in Simultaneous PET/MRI

Science.gov (United States)

Chun, Se Young; Reese, Timothy G.; Ouyang, Jinsong; Guerin, Bastien; Catana, Ciprian; Zhu, Xuping; Alpert, Nathaniel M.; El Fakhri, Georges

2014-01-01

Respiratory and cardiac motion is the most serious limitation to whole-body PET, resulting in spatial resolution close to 1 cm. Furthermore, motion-induced inconsistencies in the attenuation measurements often lead to significant artifacts in the reconstructed images. Gating can remove motion artifacts at the cost of increased noise. This paper presents an approach to respiratory motion correction using simultaneous PET/MRI to demonstrate initial results in phantoms, rabbits, and nonhuman primates and discusses the prospects for clinical application. Methods Studies with a deformable phantom, a free-breathing primate, and rabbits implanted with radioactive beads were performed with simultaneous PET/MRI. Motion fields were estimated from concurrently acquired tagged MR images using 2 B-spline nonrigid image registration methods and incorporated into a PET list-mode ordered-subsets expectation maximization algorithm. Using the measured motion fields to transform both the emission data and the attenuation data, we could use all the coincidence data to reconstruct any phase of the respiratory cycle. We compared the resulting SNR and the channelized Hotelling observer (CHO) detection signal-to-noise ratio (SNR) in the motion-corrected reconstruction with the results obtained from standard gating and uncorrected studies. Results Motion correction virtually eliminated motion blur without reducing SNR, yielding images with SNR comparable to those obtained by gating with 5–8 times longer acquisitions in all studies. The CHO study in dynamic phantoms demonstrated a significant improvement (166%–276%) in lesion detection SNR with MRI-based motion correction as compared with gating (P < 0.001). This improvement was 43%–92% for large motion compared with lesion detection without motion correction (P < 0.001). CHO SNR in the rabbit studies confirmed these results. Conclusion Tagged MRI motion correction in simultaneous PET/MRI significantly improves lesion detection

SU-G-IeP1-01: A Novel MRI Post-Processing Algorithm for Visualization of the Prostate LDR Brachytherapy Seeds and Calcifications Based On B0 Field Inhomogeneity Correction and Hough Transform

Energy Technology Data Exchange (ETDEWEB)

Nosrati, R [Reyrson University, Toronto, Ontario (Canada); Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Soliman, A; Owrangi, A [Sunnybrook Research Institute, Toronto, Ontario (Canada); Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Ghugre, N [Sunnybrook Research Institute, Toronto, Ontario (Canada); University of Toronto, Toronto, ON (Canada); Morton, G [Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); University of Toronto, Toronto, ON (Canada); Pejovic-Milic, A [Reyrson University, Toronto, Ontario (Canada); Song, W [Reyrson University, Toronto, Ontario (Canada); Sunnybrook Research Institute, Toronto, Ontario (Canada); Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); University of Toronto, Toronto, ON (Canada)

2016-06-15

Purpose: This study aims at developing an MRI-only workflow for post-implant dosimetry of the prostate LDR brachytherapy seeds. The specific goal here is to develop a post-processing algorithm to produce positive contrast for the seeds and prostatic calcifications and differentiate between them on MR images. Methods: An agar-based phantom incorporating four dummy seeds (I-125) and five calcifications of different sizes (from sheep cortical bone) was constructed. Seeds were placed arbitrarily in the coronal plane. The phantom was scanned with 3T Philips Achieva MR scanner using an 8-channel head coil array. Multi-echo turbo spin echo (ME-TSE) and multi-echo gradient recalled echo (ME-GRE) sequences were acquired. Due to minimal susceptibility artifacts around seeds, ME-GRE sequence (flip angle=15; TR/TE=20/2.3/2.3; resolution=0.7×0.7×2mm3) was further processed.The induced field inhomogeneity due to the presence of titaniumencapsulated seeds was corrected using a B0 field map. B0 map was calculated using the ME-GRE sequence by calculating the phase difference at two different echo times. Initially, the product of the first echo and B0 map was calculated. The features corresponding to the seeds were then extracted in three steps: 1) the edge pixels were isolated using “Prewitt” operator; 2) the Hough transform was employed to detect ellipses approximately matching the dimensions of the seeds and 3) at the position and orientation of the detected ellipses an ellipse was drawn on the B0-corrected image. Results: The proposed B0-correction process produced positive contrast for the seeds and calcifications. The Hough transform based on Prewitt edge operator successfully identified all the seeds according to their ellipsoidal shape and dimensions in the edge image. Conclusion: The proposed post-processing algorithm successfully visualized the seeds and calcifications with positive contrast and differentiates between them according to their shapes. Further

SU-F-BRA-13: Knowledge-Based Treatment Planning for Prostate LDR Brachytherapy Based On Principle Component Analysis

Energy Technology Data Exchange (ETDEWEB)

Roper, J; Bradshaw, B; Godette, K; Schreibmann, E [Winship Cancer Institute of Emory University, Atlanta, GA (United States); Chanyavanich, V [Rocky Mountain Cancer Centers, Denver, CO (United States)

2015-06-15

Purpose: To create a knowledge-based algorithm for prostate LDR brachytherapy treatment planning that standardizes plan quality using seed arrangements tailored to individual physician preferences while being fast enough for real-time planning. Methods: A dataset of 130 prior cases was compiled for a physician with an active prostate seed implant practice. Ten cases were randomly selected to test the algorithm. Contours from the 120 library cases were registered to a common reference frame. Contour variations were characterized on a point by point basis using principle component analysis (PCA). A test case was converted to PCA vectors using the same process and then compared with each library case using a Mahalanobis distance to evaluate similarity. Rank order PCA scores were used to select the best-matched library case. The seed arrangement was extracted from the best-matched case and used as a starting point for planning the test case. Computational time was recorded. Any subsequent modifications were recorded that required input from a treatment planner to achieve an acceptable plan. Results: The computational time required to register contours from a test case and evaluate PCA similarity across the library was approximately 10s. Five of the ten test cases did not require any seed additions, deletions, or moves to obtain an acceptable plan. The remaining five test cases required on average 4.2 seed modifications. The time to complete manual plan modifications was less than 30s in all cases. Conclusion: A knowledge-based treatment planning algorithm was developed for prostate LDR brachytherapy based on principle component analysis. Initial results suggest that this approach can be used to quickly create treatment plans that require few if any modifications by the treatment planner. In general, test case plans have seed arrangements which are very similar to prior cases, and thus are inherently tailored to physician preferences.

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

OpenAIRE

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

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...

Evolution of brachytherapy for prostate carcinoma

International Nuclear Information System (INIS)

Qin Lan

2005-01-01

Brachytherapy is one of the most main management to prostate carcinoma. This method has been rapidly accepted in clinical application since it is a convenient, little-traumatic, and outpatient therapy. With the development of techniques of production of radio-seeds, imaging modality and three-dimensional radiotherapy plan system, brachytherapy has been made a virtually progress in improving curative-effect and reducing damage to surrounding normal tissue. (authors)

Computed tomography in brachytherapy

International Nuclear Information System (INIS)

Mansfield, C.M.; Lee, K.R.; Dwyer, S.; Zellmer, D.; Cook, P.

1983-01-01

CT scanning adds to the ability to evaluate brachytherapy techniques. It provides an additional method in the assessment of patients who are candidates for or who are being treated by brachytherapy. The CT scan can give information regarding the position of the sources and their relation to the tumor and normal structures with greater ease than do orthogonal views. This makes it possible to accurately calculate areas of high or low dose. Potential areas of overdose can be recognized, thereby decreasing the chances of postbrachytherapy complications. CT scanning can be used at various levels of complexity in dosimetry evaluation. Adequate brachytherapy dosimetry information is obtainable from CT slices through one or more levels of the implanted volume. In some instances it is possible to obtain additional information by reconstructing the scans in other planes, e.g., coronal or sagittal. Three-dimensional viewing of the implant is desirable, but it should be pointed out that this approach is time-consuming and beyond the capabilities of most institutions at present. It will be necessary to continue work on three-dimensional treatment planning to make it readily available

The Meaning and Experience of Patients Undergoing Rectal High-Dose-Rate Brachytherapy.

Science.gov (United States)

Perez, Samara; Néron, Sylvain; Benc, Renata; Rosberger, Zeev; Vuong, Té

2016-01-01

High-dose-rate (HDR) brachytherapy is a precise form of radiation therapy that targets cancerous tumors by directly applying the radiation source at the site or directly next to the tumor. Patients often experience but underreport pain and anxiety related to cancer treatments. At present, there is no research available concerning the pervasiveness and intensity of patients' pain and anxiety during rectal brachytherapy. The aim of this study was to examine patients' thoughts, emotions, coping strategies, physical sensations, and needs during rectal HDR brachytherapy treatment. Twenty-five patients with rectal cancer were interviewed using a semi-structured qualitative interview following the completion of their brachytherapy treatment delivered at a Montreal-based hospital in Quebec, Canada. The experiences of pain and discomfort varied greatly between patients and were linked to the meaning patients attributed to the treatment itself, sense of time, the body's lithotomic position, insertion of the treatment applicator, and the patients' sense of agency and empowerment during the procedure. Patients drew upon a variety of internal and external resources to help them cope with discomfort. Staff need to know about the variation in the physical and emotional experiences of patients undergoing this treatment. Clinical teams can tailor their procedural behavior (eg, using certain language, psychosocial interventions) according to patients' needs to increase patients' comfort and ultimately improve their experience of HDR rectal brachytherapy.

Brachytherapy in the treatment of head and neck cancer

International Nuclear Information System (INIS)

Yoo, Seong Yul

1999-01-01

Brachytherapy has been proved to be an effective method for the purpose of increasing radiation dose to the tumor and reducing the dose to the surrounding normal tissue. In head and neck cancer, the rationale of brachytherapy is as follows; Firstly, early small lesion is radiocurative and the major cause of failure is local recurrence. Secondly, it can diminish evidently the dose to the normal tissue especially masseteric muscle and salivary gland. Thirdly, the anatomy of head and neck is suitable to various technique of brachytherapy. On background of accumulated experience of LDR iridium brachytherapy of head and neck cancer for the last 15 years, the author reviewed the history of radioisotope therapy, the characteristics of radionuclides, and some important things in the method, clinical technique and treatment planning. The author analyzed the clinical result of 185 cases of head and neck cancer treated in the Korea Cancer Center Hospital. Finally the future prospect of brachytherapy of head and neck cancer is discussed

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

International Nuclear Information System (INIS)

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

Methods for prostate stabilization during transperineal LDR brachytherapy.

Science.gov (United States)

Podder, Tarun; Sherman, Jason; Rubens, Deborah; Messing, Edward; Strang, John; Ng, Wan-Sing; Yu, Yan

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

Methods for prostate stabilization during transperineal LDR brachytherapy

International Nuclear Information System (INIS)

Podder, Tarun; Yu Yan; Sherman, Jason; Rubens, Deborah; Strang, John; Messing, Edward; Ng, Wan-Sing

2008-01-01

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

Results of the intestitial brachytherapy and of the combination external radiation-brachytherapy in 150 patients with carcinoma of the oral tongue and floor of the mouth

Energy Technology Data Exchange (ETDEWEB)

Sannazzari, G L; Negri, G L; Ozzello, F

1986-01-01

The authors report their experience on the treatment of carcinoma of the oral tongue and floor of the mouth with interstitial brachytherapy, alone or in conbination with external irradiation. One hundred and fifty patients were treated; among these, 116 with brachytherapy alone, 34 with combined treatment. The five years local control in those patients treated with brachytherapy alone was 72.5% in T1, 61.2% in T2 and 35% in T3; in those patients treated with external irradiation and brachytherapy the global five years control was 42.5%. The global five years survival was 64% in the patients treated with brachytherapy alone 48% in the patients treated with combined therapy. 42 refs.

Results of the intestitial brachytherapy and of the combination external radiation-brachytherapy in 150 patients with carcinoma of the oral tongue and floor of the mouth

International Nuclear Information System (INIS)

Sannazzari, G.L.; Negri, G.L.; Ozzello, F.

1986-01-01

The authors report their experience on the treatment of carcinoma of the oral tongue and floor of the mouth with interstitial brachytherapy, alone or in conbination with external irradiation. One hundred and fifty patients were treated; among these, 116 with brachytherapy alone, 34 with combined treatment. The five years local control in those patients treated with brachytherapy alone was 72.5% in T1, 61.2% in T2 and 35% in T3; in those patients treated with external irradiation and brachytherapy the global five years control was 42.5%. The global five years survival was 64% in the patients treated with brachytherapy alone 48% in the patients treated with combined therapy

MRI-based decision tree model for diagnosis of biliary atresia.

Science.gov (United States)

Kim, Yong Hee; Kim, Myung-Joon; Shin, Hyun Joo; Yoon, Haesung; Han, Seok Joo; Koh, Hong; Roh, Yun Ho; Lee, Mi-Jung

2018-02-23

To evaluate MRI findings and to generate a decision tree model for diagnosis of biliary atresia (BA) in infants with jaundice. We retrospectively reviewed features of MRI and ultrasonography (US) performed in infants with jaundice between January 2009 and June 2016 under approval of the institutional review board, including the maximum diameter of periportal signal change on MRI (MR triangular cord thickness, MR-TCT) or US (US-TCT), visibility of common bile duct (CBD) and abnormality of gallbladder (GB). Hepatic subcapsular flow was reviewed on Doppler US. We performed conditional inference tree analysis using MRI findings to generate a decision tree model. A total of 208 infants were included, 112 in the BA group and 96 in the non-BA group. Mean age at the time of MRI was 58.7 ± 36.6 days. Visibility of CBD, abnormality of GB and MR-TCT were good discriminators for the diagnosis of BA and the MRI-based decision tree using these findings with MR-TCT cut-off 5.1 mm showed 97.3 % sensitivity, 94.8 % specificity and 96.2 % accuracy. MRI-based decision tree model reliably differentiates BA in infants with jaundice. MRI can be an objective imaging modality for the diagnosis of BA. • MRI-based decision tree model reliably differentiates biliary atresia in neonatal cholestasis. • Common bile duct, gallbladder and periportal signal changes are the discriminators. • MRI has comparable performance to ultrasonography for diagnosis of biliary atresia.

In vivo assessment of catheter positioning accuracy and prolonged irradiation time on liver tolerance dose after single-fraction 192Ir high-dose-rate brachytherapy

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Kropf Siegfried

2011-09-01

Full Text Available Abstract Background To assess brachytherapy catheter positioning accuracy and to evaluate the effects of prolonged irradiation time on the tolerance dose of normal liver parenchyma following single-fraction irradiation with 192 Ir. Materials and methods Fifty patients with 76 malignant liver tumors treated by computed tomography (CT-guided high-dose-rate brachytherapy (HDR-BT were included in the study. The prescribed radiation dose was delivered by 1 - 11 catheters with exposure times in the range of 844 - 4432 seconds. Magnetic resonance imaging (MRI datasets for assessing irradiation effects on normal liver tissue, edema, and hepatocyte dysfunction, obtained 6 and 12 weeks after HDR-BT, were merged with 3D dosimetry data. The isodose of the treatment plan covering the same volume as the irradiation effect was taken as a surrogate for the liver tissue tolerance dose. Catheter positioning accuracy was assessed by calculating the shift between the 3D center coordinates of the irradiation effect volume and the tolerance dose volume for 38 irradiation effects in 30 patients induced by catheters implanted in nearly parallel arrangement. Effects of prolonged irradiation were assessed in areas where the irradiation effect volume and tolerance dose volume did not overlap (mismatch areas by using a catheter contribution index. This index was calculated for 48 irradiation effects induced by at least two catheters in 44 patients. Results Positioning accuracy of the brachytherapy catheters was 5-6 mm. The orthogonal and axial shifts between the center coordinates of the irradiation effect volume and the tolerance dose volume in relation to the direction vector of catheter implantation were highly correlated and in first approximation identically in the T1-w and T2-w MRI sequences (p = 0.003 and p p = 0.001 and p = 0.004, respectively. There was a significant shift of the irradiation effect towards the catheter entry site compared with the planned dose

Commissioning of a grid-based Boltzmann solver for cervical cancer brachytherapy treatment planning with shielded colpostats.

Science.gov (United States)

Mikell, Justin K; Klopp, Ann H; Price, Michael; Mourtada, Firas

2013-01-01

We sought to commission a gynecologic shielded colpostat analytic model provided from a treatment planning system (TPS) library. We have reported retrospectively the dosimetric impact of this applicator model in a cohort of patients. A commercial TPS with a grid-based Boltzmann solver (GBBS) was commissioned for (192)Ir high-dose-rate (HDR) brachytherapy for cervical cancer with stainless steel-shielded colpostats. Verification of the colpostat analytic model was verified using a radiograph and vendor schematics. MCNPX v2.6 Monte Carlo simulations were performed to compare dose distributions around the applicator in water with the TPS GBBS dose predictions. Retrospectively, the dosimetric impact was assessed over 24 cervical cancer patients' HDR plans. Applicator (TPS ID #AL13122005) shield dimensions were within 0.4 mm of the independent shield dimensions verification. GBBS profiles in planes bisecting the cap around the applicator agreed with Monte Carlo simulations within 2% at most locations; differing screw representations resulted in differences of up to 9%. For the retrospective study, the GBBS doses differed from TG-43 as follows (mean value ± standard deviation [min, max]): International Commission on Radiation units [ICRU]rectum (-8.4 ± 2.5% [-14.1, -4.1%]), ICRUbladder (-7.2 ± 3.6% [-15.7, -2.1%]), D2cc-rectum (-6.2 ± 2.6% [-11.9, -0.8%]), D2cc-sigmoid (-5.6 ± 2.6% [-9.3, -2.0%]), and D2cc-bladder (-3.4 ± 1.9% [-7.2, -1.1%]). As brachytherapy TPSs implement advanced model-based dose calculations, the analytic applicator models stored in TPSs should be independently validated before clinical use. For this cohort, clinically meaningful differences (>5%) from TG-43 were observed. Accurate dosimetric modeling of shielded applicators may help to refine organ toxicity studies. Copyright © 2013 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Dosimetric comparison between intensity modulated brachytherapy versus external beam intensity modulated radiotherapy for cervix cancer: a treatment planning study

International Nuclear Information System (INIS)

Subramani, V.; Sharma, D.N.; Jothy Basu, K.S.; Rath, G.K.; Gopishankar, N.

2008-01-01

To evaluate the dosimetric superiority of intensity modulated brachytherapy (IMBT) based on inverse planning optimization technique with classical brachytherapy optimization and also with external beam intensity modulated radiotherapy planning technique in patients of cervical carcinoma

Spectroscopic characterization of low dose rate brachytherapy sources

Science.gov (United States)

Beach, Stephen M.

The low dose rate (LDR) brachytherapy seeds employed in permanent radioactive-source implant treatments usually use one of two radionuclides, 125I or 103Pd. The theoretically expected source spectroscopic output from these sources can be obtained via Monte Carlo calculation based upon seed dimensions and materials as well as the bare-source photon emissions for that specific radionuclide. However the discrepancies resulting from inconsistent manufacturing of sources in comparison to each other within model groups and simplified Monte Carlo calculational geometries ultimately result in undesirably large uncertainties in the Monte Carlo calculated values. This dissertation describes experimentally attained spectroscopic outputs of the clinically used brachytherapy sources in air and in liquid water. Such knowledge can then be applied to characterize these sources by a more fundamental and metro logically-pure classification, that of energy-based dosimetry. The spectroscopic results contained within this dissertation can be utilized in the verification and benchmarking of Monte Carlo calculational models of these brachytherapy sources. This body of work was undertaken to establish a usable spectroscopy system and analysis methods for the meaningful study of LDR brachytherapy seeds. The development of a correction algorithm and the analysis of the resultant spectroscopic measurements are presented. The characterization of the spectrometer and the subsequent deconvolution of the measured spectrum to obtain the true spectrum free of any perturbations caused by the spectrometer itself is an important contribution of this work. The approach of spectroscopic deconvolution that was applied in this work is derived in detail and it is applied to the physical measurements. In addition, the spectroscopically based analogs to the LDR dosimetry parameters that are currently employed are detailed, as well as the development of the theory and measurement methods to arrive at these

Outcomes and toxicities in patients with intermediate-risk prostate cancer treated with brachytherapy alone or brachytherapy and supplemental external beam radiation therapy.

Science.gov (United States)

Schlussel Markovic, Emily; Buckstein, Michael; Stone, Nelson N; Stock, Richard G

2018-05-01

To evaluate the cancer control outcomes and long-term treatment-related morbidity of brachytherapy as well as combination brachytherapy and external beam radiation therapy (EBRT) in patients with intermediate-risk prostate cancer. A retrospective review was conducted in a prospectively collected database of patients with intermediate-risk prostate cancer who were treated either with brachytherapy or brachytherapy and EBRT, with or without androgen deprivation therapy (ADT), in the period 1990-2014. Urinary and erectile dysfunction symptoms were measured using the International Prostate Symptom Score (IPSS), the Mount Sinai erectile function scale and the Sexual Health Inventory for Men (SHIM). Cancer control endpoints included biochemical failure and development of distant metastases. All statistical analyses were carried out using the Statistical Package for Social Science (SPSS). Survival curves were calculated using Kaplan-Meier actuarial methods and compared using log-rank tests. Cox regression multivariate analyses were used to test the effect of multiple variables on treatment outcomes. A total of 902 patients were identified, with a median follow-up of 91 months. Of these, 390 received brachytherapy and 512 received combination therapy with EBRT. In patients with one intermediate-risk factor, the addition of EBRT did not significantly affect freedom from biochemical failure or distant metastases. Among patients with two or three intermediate-risk factors, added EBRT did not improve freedom from biochemical failure. Significant differences in late toxicity between patients treated with brachytherapy vs combination brachytherapy and EBRT were identified including urge incontinence (P actuarial methods showed that patients receiving combination therapy more frequently experienced loss of potency, as measured by the Mount Sinai erectile function scale (P = 0.040). Brachytherapy monotherapy results in equal biochemical and distant control in both patients with

Brachytherapy for carcinoma of the cervix: A Canadian survey of practice patterns in a changing era

International Nuclear Information System (INIS)

Pearce, Andrew; Craighead, Peter; Kay, Ian; Traptow, Laurel; Doll, Corinne

2009-01-01

Background and purpose: This survey aimed to document practices of Canadian radiation oncologists performing gynecologic brachytherapy for carcinoma of the cervix and to determine what the effect of the phasing-out of LDR after-loading systems from the commercial market is having on practice. Materials and methods: A 26-item questionnaire was developed to survey various aspects of brachytherapy practice to include: number of patients treated, prescription points/volume, dose and fractionation, timing, critical structure delineation, expected changes due to the phasing-out of support for low dose rate systems, and support for the development of national guidelines. A link to a web-based survey collection instrument was emailed to each radiation oncologist in Canada practicing gynecologic brachytherapy. Results: A 67% response rate was achieved in this web-based survey. Radiation oncologists currently using HDR brachytherapy are most commonly delivering 5 fractions of 6 Gy in addition to an EBRT dose of 45 Gy in 25 fractions. The median total dose equivalents to Point A was 82.9 Gy for both early and advanced disease. In response to the announcement by a major vendor that they would be phasing-out service for a popular LDR after-loader, 49% of Canadian radiation oncologists who practice brachytherapy for cervix cancer are changing to an HDR technique with a further 9% changing to a PDR technique. Eighty-six percent of respondents would support the development of national guidelines for cervix brachytherapy in Canada. Conclusions: Variation in practice exists in Canada in brachytherapy for cervix cancer. Many centers are in the process of phasing-out LDR techniques in response to the withdrawal of commercial support for these systems. Support for the development of Canadian national guidelines is high.

Patch-based generation of a pseudo CT from conventional MRI sequences for MRI-only radiotherapy of the brain

DEFF Research Database (Denmark)

Andreasen, Daniel; Van Leemput, Koen; Hansen, Rasmus H.

2015-01-01

scans. In this study, we investigate the potential of a patch-based method for creating a pCT based on conventional T1-weighted MRI scans without using deformable registrations. We compare this method against two state-of-the-art methods within the voxel-based and atlas-based categories. Methods...... based on water equivalent path lengths was carried out, comparing the upper hemisphere of the head in the pCT and the real CT. Finally, the dosimetric accuracy was tested and compared for a photon treatment plan. Results:The pCTs produced with the patch-based method had the best voxel-wise, geometric......Purpose: In radiotherapy (RT) based on magnetic resonance imaging (MRI) as the only modality, the information on electron density must be derived from the MRI scan by creating a so-called pseudo computed tomography (pCT). This is a nontrivial task, since the voxel-intensities in an MRI scan...

Ocular brachytherapy with a holmium-166 irradiator device

International Nuclear Information System (INIS)

Mourao, Arnaldo P.; Campos, Tarcisio P.R.

2009-01-01

The ocular brachytherapy is a method that allows controlling ocular tumors. However, the irradiation of the ocular area in high doses can bring damages mainly to the surrounding healthy tissue, such as lens, retina and bone tissue of the orbital area in growth phase. Brachytherapy in comparison to teletherapy allows a large reduction of the absorbed doses in the adjacent tissues avoiding deleterious effects. Various types of radionuclides can be applied to ocular brachytherapy. Those radionuclides shall be encapsulated and placed juxtaposed to the sclera, back to the tumor. Herein, a new device was developed to encapsulate the radioactive material. It can easily place back of the eyeball. A computational model of the ocular area was developed in order to simulate the spatial dose distribution promoted by the holmium-166 nuclide distributed inside the irradiator device. The simulations addressed a device placed on the surface of the sclera, rotated 90 deg taken at the normal axis forward to the lens. The simulation was carried on the code Monte Carlo MCNP5. The computational simulation generates the spatial dose distribution in the treated volume. All continuous beta and the discrete gamma and X-ray spectra emitted by the holmium-166 were incorporated on simulations. The results allow comparing the space dose distribution to other types of sources used for the same end. The sclera absorbed dose, the maximum apical tumor dose, as well as on the tumor base were investigated. Indeed, the tumor thickness defines the conditions of irradiation. The holmium-166 dose distribution provides a tool to propose a better and optimized protocol for ocular brachytherapy. (author)

Ocular brachytherapy with a holmium-166 irradiator device

Energy Technology Data Exchange (ETDEWEB)

Mourao, Arnaldo P. [Centro Federal de Educacao Tecnoloica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil). Nucleo de Engenharia Hospitalar], e-mail: aprata@des.cefetmg.br; Campos, Tarcisio P.R. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-graduacao em Ciencias e Tecnicas Nucleares], e-mail: campos@nuclear.ufmg.br

2009-07-01

The ocular brachytherapy is a method that allows controlling ocular tumors. However, the irradiation of the ocular area in high doses can bring damages mainly to the surrounding healthy tissue, such as lens, retina and bone tissue of the orbital area in growth phase. Brachytherapy in comparison to teletherapy allows a large reduction of the absorbed doses in the adjacent tissues avoiding deleterious effects. Various types of radionuclides can be applied to ocular brachytherapy. Those radionuclides shall be encapsulated and placed juxtaposed to the sclera, back to the tumor. Herein, a new device was developed to encapsulate the radioactive material. It can easily place back of the eyeball. A computational model of the ocular area was developed in order to simulate the spatial dose distribution promoted by the holmium-166 nuclide distributed inside the irradiator device. The simulations addressed a device placed on the surface of the sclera, rotated 90 deg taken at the normal axis forward to the lens. The simulation was carried on the code Monte Carlo MCNP5. The computational simulation generates the spatial dose distribution in the treated volume. All continuous beta and the discrete gamma and X-ray spectra emitted by the holmium-166 were incorporated on simulations. The results allow comparing the space dose distribution to other types of sources used for the same end. The sclera absorbed dose, the maximum apical tumor dose, as well as on the tumor base were investigated. Indeed, the tumor thickness defines the conditions of irradiation. The holmium-166 dose distribution provides a tool to propose a better and optimized protocol for ocular brachytherapy. (author)

Development of the Dutch primary standard for beta-emitting brachytherapy sources

International Nuclear Information System (INIS)

Marel, J. an der; Dijk, E. van

2002-01-01

The application of β-radiation emitting radioactive sources in medicine is rapidly expanding. An important new application is the use of β-radiation emitting radioactive sources in endovascular brachytherapy to avoid restenosis. Another well-known application is the use of the ophthalmic applicator (flat or concave surface source) for the treatment of tumors in the eye. Dose and dose distributions are very important characteristics of brachytherapy sources. The absorbed dose in the treated tissue should be known accurately to assure a good quality of the treatment and to develop new treatment methods and source configurations. At the Nederland s Meetinstituut (NMi) a project is going on for the development of a primary standard for betadosimetry. With this standard, dose and dose distributions of β-sources as used in brachytherapy can be measured in terms of absorbed dose to water. The primary standard is based on an extrapolation chamber. The extrapolation chamber will become part of a quality assurance system in Dutch hospitals for endovascular brachytherapy sources. The quality assurance system will further consist of transfer standards like well-type ionisation chambers, plastic scintillator systems and radiochromic film dosimetry. Apart from the endovascular sources the extrapolation chamber will be used to characterize ophthalmic applicators

Utilization and Outcomes of Breast Brachytherapy in Younger Women

International Nuclear Information System (INIS)

Smith, Grace L.; Huo, Jinhai; Giordano, Sharon H.; Hunt, Kelly K.; Buchholz, Thomas A.; Smith, Benjamin D.

2015-01-01

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

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

Optical fibre luminescence sensor for real-time LDR brachytherapy dosimetry

Science.gov (United States)

Woulfe, P.; O'Keeffe, S.; Sullivan, F. J.

2018-02-01

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 developed, based on radioluminescence whereby radiation sensitive scintillation material, terbium doped gadolinium oxysulphide (Gd2O2S:Tb), is embedded in a cavity of 700μm of a 1mm plastic optical fibre. The sensor is designed for in-vivo monitoring of the radiation dose during radio-active seed implantation for low dose rate (LDR) brachytherapy, in prostate cancer treatment, providing radiation oncologists with real-time information of the radiation dose to the target area and/or nearby organs at risk (OARs). 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 0.397mCi of Iodine125, the radioactive source most commonly used in brachytherapy for treating prostate cancer.

Patient effective dose from endovascular brachytherapy with {sup 192}Ir Sources

Energy Technology Data Exchange (ETDEWEB)

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

2002-07-01

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 {sup 192}Ir 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 Rando 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 coronary treatment were 2.4x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for lung, 0.9x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for oesophagus and 0.48x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for bone marrow. During brachytherapy of the renal artery, the corresponding normalised doses were 4.2x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for colon, 7.8x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for stomach and 1.7x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for liver. Coronary treatment involved an effective dose of 0.046 mSv.GBq{sup -1}.min{sup -1}, whereas the treatment of the renal artery resulted in an effective dose of 0.15 mSv.GBq{sup -1}.min{sup -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. (author)

Perioperative high dose rate (HDR brachytherapy in unresectable locally advanced pancreatic tumors

Directory of Open Access Journals (Sweden)

Brygida Białas

2011-07-01

Full Text Available Purpose: The aim of the study was to present an original technique of catheter implantation for perioperative HDR-Ir192 brachytherapy in patients after palliative operations of unresectable locally advanced pancreatic tumors and to estimate the influence of perioperative HDR-Ir192 brachytherapy on pain relief in terminal pancreatic cancer patients. Material and methods: Eight patients with pancreatic tumors located in the head of pancreas underwent palliative operations with the use of HDR-Ir192 brachytherapy. All patients qualified for surgery reported pain of high intensity and had received narcotic painkillers prior to operation. During the last phase of the surgery, the Nucletron® catheters were implanted in patients to prepare them for later perioperative brachytherapy. Since the 6th day after surgery HDR brachytherapy was performed. Before each brachytherapy fraction the location of implants were checked using fluoroscopy. A fractional dose was 5 Gy and a total dose was 20 Gy in the area of radiation. A comparative study of two groups of patients (with and without brachytherapy with stage III pancreatic cancer according to the TNM scale was taken in consideration. Results and Conclusions: The authors claim that the modification of catheter implantation using specially designed cannula, facilitates the process of inserting the catheter into the tumor, shortens the time needed for the procedure, and reduces the risk of complications. Mean survival time was 5.7 months. In the group of performed brachytherapy, the mean survival time was 6.7 months, while in the group of no brachytherapy performed – 4.4 months. In the group of brachytherapy, only one patient increased the dose of painkillers in the last month of his life. Remaining patients took constant doses of medicines. Perioperative HDR-Ir192 brachytherapy could be considered as a practical application of adjuvant therapy for pain relief in patients with an advanced pancreatic cancer.

Monte-Carlo based assessment of MAGIC, MAGICAUG, PAGATUG and PAGATAUG polymer gel dosimeters for ovaries and uterus organ dosimetry in brachytherapy, nuclear medicine and Tele-therapy.

Science.gov (United States)

Adinehvand, Karim; Rahatabad, Fereidoun Nowshiravan

2018-06-01

Calculation of 3D dose distribution during radiotherapy and nuclear medicine helps us for better treatment of sensitive organs such as ovaries and uterus. In this research, we investigate two groups of normoxic dosimeters based on meta-acrylic acid (MAGIC and MAGICAUG) and polyacrylamide (PAGATUG and PAGATAUG) for brachytherapy, nuclear medicine and Tele-therapy in their sensitive and critical role as organ dosimeters. These polymer gel dosimeters are compared with soft tissue while irradiated by different energy photons in therapeutic applications. This comparison has been simulated by Monte-Carlo based MCNPX code. ORNL phantom-Female has been used to model the critical organs of kidneys, ovaries and uterus. Right kidney is proposed to be the source of irradiation and another two organs are exposed to this irradiation. Effective atomic numbers of soft tissue, MAGIC, MAGICAUG, PAGATUG and PAGATAUG are 6.86, 7.07, 6.95, 7.28, and 7.07 respectively. Results show the polymer gel dosimeters are comparable to soft tissue for using in nuclear medicine and Tele-therapy. Differences between gel dosimeters and soft tissue are defined as the dose responses. This difference is less than 4.1%, 22.6% and 71.9% for Tele-therapy, nuclear medicine and brachytherapy respectively. The results approved that gel dosimeters are the best choice for ovaries and uterus in nuclear medicine and Tele-therapy respectively. Due to the slight difference between the effective atomic numbers of these polymer gel dosimeters and soft tissue, these polymer gels are not suitable for brachytherapy since the dependence of photon interaction to atomic number, for low energy brachytherapy, had been so effective. Also this dependence to atomic number, decrease for photoelectric and increase for Compton. Therefore polymer gel dosimeters are not a good alternative to soft tissue replacement in brachytherapy. Copyright © 2018 Elsevier B.V. All rights reserved.

Role of brachytherapy in the treatment of localized prostate cancer

Directory of Open Access Journals (Sweden)

A. D. Kaprin

2015-01-01

Full Text Available The review is devoted to application of brachytherapy for treating the localized prostate cancer (PC. Statistics for incidence and detectability of this pathology and its dynamics for recent years are represented. Brief analysis of other methods which are conveniently used for treatment of PC, such as radical prostatectomy and external-beam radiotherapy, was performed. Advantages and disadvantages of these methods have been discussed. Brief history about the development of brachytherapy from first experience to wide-spread use in clinical practice is reported. The detailed review of series of large trials from Russia and other countries for efficiency and safety of brachytherapy in patients with prostate cancer for recent 15 years is also represented. Two types of brachytherapy in current clinical oncology i.e. low-dose technique with permanent implantation of microsources and high-dose temporary isotope implantation, specifics of its application in different groups of patients have been described. The procedure of brachytherapy and its three main steps i.e. planning, implantation and control assessment after implantation have been characterized in details. The conclusion about benefits of using of brachytherapy in the treatment of prostate cancer as minimally invasive and efficient method was made. 

Quality control of brachytherapy equipment in the Netherlands and Belgium: current practice and minimum requirements

International Nuclear Information System (INIS)

Elfrink, Robert J.M.; Kolkman-Deurloo, Inger-Karine K.; Kleffens, Herman J. van; Rijnders, Alex; Schaeken, Bob; Aalbers, Tony H.L.; Dries, Wim J.F.; Venselaar, Jack L.M.

2002-01-01

Background and purpose: Brachytherapy is applied in 39 radiotherapy institutions in The Netherlands and Belgium. Each institution has its own quality control (QC) programme to ensure safe and accurate dose delivery to the patient. The main goal of this work is to gain insight into the current practice of QC of brachytherapy in The Netherlands and Belgium and to reduce possible variations in test frequencies and tolerances by formulating a set of minimum QC-requirements. Materials and methods: An extensive questionnaire about QC of brachytherapy was distributed to and completed by the 39 radiotherapy institutions. A separate smaller questionnaire was sent to nine institutions performing intracoronary brachytherapy. The questions were related to safety systems, physical irradiation parameters and total time spent on QC. The results of the questionnaires were compared with recommendations given in international brachytherapy QC reports. Results: The answers to the questionnaires showed large variations in test frequencies and test methods. Furthermore, large variations in time spent on QC exist, which is mainly due to differences in QC-philosophy and differences in the available resources. Conclusions: Based on the results of the questionnaires and the comparison with the international recommendations, a set of minimum requirements for QC of brachytherapy has been formulated. These guidelines will be implemented in the radiotherapy institutions in The Netherlands and Belgium

Brachytherapy. High dose rate brachytherapy - Radiation protection: medical sheet ED 4287

International Nuclear Information System (INIS)

Celier, D.; Aubert, B.; Vidal, J.P.; Biau, A.; Lahaye, T.; Gauron, C.; Barret, C.; Boisserie, G.; Branchet, E.; Gambini, D.; Gondran, C.; Le Guen, B.; Guerin, C.; Nguyen, S.; Pierrat, N.; Sarrazin, T.; Donnarieix, D.

2010-02-01

After having indicated the required authorization to implement brachytherapy techniques, this document presents the various aspects and measures related to radiation protection when performing high-dose-rate brachytherapy treatments. It presents the concerned personnel, describes the operational process, indicates the associated hazards and the risk related to ionizing radiation, and describes how the risk is to be assessed and how exposure levels are to be determined (elements of risk assessment, delimitation of controlled and monitored areas, personnel classification, and choice of the dose monitoring method). It describes the various components of a risk management strategy (risk reduction, technical measures regarding the installation and the personnel, training and information, prevention and medical monitoring). It briefly presents how risk management is to be assessed, and mentions other related risks (biological risk, handling and posture, handling of heavy loads, mental workload, chemical risk)

Brachytherapy. Pulsed dose rate brachytherapy - Radiation protection: medical sheet ED 4250

International Nuclear Information System (INIS)

Celier, D.; Aubert, B.; Vidal, J.P.; Biau, A.; Lahaye, T.; Gauron, C.; Barret, C.; Boisserie, G.; Branchet, E.; Gambini, D.; Gondran, C.; Le Guen, B.; Guerin, C.; Nguyen, S.; Pierrat, N.; Sarrazin, T.; Donnarieix, D.

2009-06-01

After having indicated the required authorization to implement brachytherapy techniques, this document presents the various aspects and measures related to radiation protection when performing pulsed-dose-rate brachytherapy treatments. It presents the concerned personnel, describes the operational process, indicates the associated hazards and the risk related to ionizing radiation, and describes how the risk is to be assessed and how exposure levels are to be determined (elements of risk assessment, delimitation of controlled and monitored areas, personnel classification, and choice of the dose monitoring method). It describes the various components of a risk management strategy (risk reduction, technical measures regarding the installation and the personnel, training and information, prevention and medical monitoring). It briefly presents how risk management is to be assessed, and mentions other related risks (biological risk, handling and posture, handling of heavy loads, mental workload, chemical risk)

Resting-State Seed-Based Analysis: An Alternative to Task-Based Language fMRI and Its Laterality Index.

Science.gov (United States)

Smitha, K A; Arun, K M; Rajesh, P G; Thomas, B; Kesavadas, C

2017-06-01

Language is a cardinal function that makes human unique. Preservation of language function poses a great challenge for surgeons during resection. The aim of the study was to assess the efficacy of resting-state fMRI in the lateralization of language function in healthy subjects to permit its further testing in patients who are unable to perform task-based fMRI. Eighteen healthy right-handed volunteers were prospectively evaluated with resting-state fMRI and task-based fMRI to assess language networks. The laterality indices of Broca and Wernicke areas were calculated by using task-based fMRI via a voxel-value approach. We adopted seed-based resting-state fMRI connectivity analysis together with parameters such as amplitude of low-frequency fluctuation and fractional amplitude of low-frequency fluctuation (fALFF). Resting-state fMRI connectivity maps for language networks were obtained from Broca and Wernicke areas in both hemispheres. We performed correlation analysis between the laterality index and the z scores of functional connectivity, amplitude of low-frequency fluctuation, and fALFF. Pearson correlation analysis between signals obtained from the z score of fALFF and the laterality index yielded a correlation coefficient of 0.849 ( P laterality index yielded an R 2 value of 0.721, indicating that 72.1% of the variance in the laterality index of task-based fMRI could be predicted from the fALFF of resting-state fMRI. The present study demonstrates that fALFF can be used as an alternative to task-based fMRI for assessing language laterality. There was a strong positive correlation between the fALFF of the Broca area of resting-state fMRI with the laterality index of task-based fMRI. Furthermore, we demonstrated the efficacy of fALFF for predicting the laterality of task-based fMRI. © 2017 by American Journal of Neuroradiology.

Vaginal dose de-escalation in image guided adaptive brachytherapy for locally advanced cervical cancer

DEFF Research Database (Denmark)

Mohamed, Sandy; Lindegaard, Jacob Christian; de Leeuw, Astrid A C

2016-01-01

Purpose Vaginal stenosis is a major problem following radiotherapy in cervical cancer. We investigated a new dose planning strategy for vaginal dose de-escalation (VDD). Materials and methods Fifty consecutive locally advanced cervical cancer patients without lower or middle vaginal involvement...... at diagnosis from 3 institutions were analysed. External beam radiotherapy was combined with MRI-guided brachytherapy. VDD was obtained by decreasing dwell times in ovoid/ring and increasing dwell times in tandem/needles. The aim was to maintain the target dose (D90 of HR-CTV ⩾ 85 Gy EQD2) while reducing...... bladder and rectum (D2cm3) were reduced by 2 ± 2 Gy and 3 ± 2 Gy, respectively (p

High Dose-Rate Versus Low Dose-Rate Brachytherapy for Lip Cancer

Energy Technology Data Exchange (ETDEWEB)

Ghadjar, Pirus, E-mail: pirus.ghadjar@insel.ch [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland); Bojaxhiu, Beat [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland); Simcock, Mathew [Swiss Group for Clinical Cancer Research Coordinating Center, Bern (Switzerland); Terribilini, Dario; Isaak, Bernhard [Division of Medical Radiation Physics, Inselspital, Bern University Hospital, and University of Bern, Bern (Switzerland); Gut, Philipp; Wolfensberger, Patrick; Broemme, Jens O.; Geretschlaeger, Andreas; Behrensmeier, Frank; Pica, Alessia; Aebersold, Daniel M. [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland)

2012-07-15

Purpose: To analyze the outcome after low-dose-rate (LDR) or high-dose-rate (HDR) brachytherapy for lip cancer. Methods and Materials: One hundred and three patients with newly diagnosed squamous cell carcinoma of the lip were treated between March 1985 and June 2009 either by HDR (n = 33) or LDR brachytherapy (n = 70). Sixty-eight patients received brachytherapy alone, and 35 received tumor excision followed by brachytherapy because of positive resection margins. Acute and late toxicity was assessed according to the Common Terminology Criteria for Adverse Events 3.0. Results: Median follow-up was 3.1 years (range, 0.3-23 years). Clinical and pathological variables did not differ significantly between groups. At 5 years, local recurrence-free survival, regional recurrence-free survival, and overall survival rates were 93%, 90%, and 77%. There was no significant difference for these endpoints when HDR was compared with LDR brachytherapy. Forty-two of 103 patients (41%) experienced acute Grade 2 and 57 of 103 patients (55%) experienced acute Grade 3 toxicity. Late Grade 1 toxicity was experienced by 34 of 103 patients (33%), and 5 of 103 patients (5%) experienced late Grade 2 toxicity; no Grade 3 late toxicity was observed. Acute and late toxicity rates were not significantly different between HDR and LDR brachytherapy. Conclusions: As treatment for lip cancer, HDR and LDR brachytherapy have comparable locoregional control and acute and late toxicity rates. HDR brachytherapy for lip cancer seems to be an effective treatment with acceptable toxicity.

Comparative study of LDR (Manchester system) and HDR image-guided conformal brachytherapy of cervical cancer: patterns of failure, late complications, and survival.

Science.gov (United States)

Narayan, Kailash; van Dyk, Sylvia; Bernshaw, David; Rajasooriyar, Chrishanthi; Kondalsamy-Chennakesavan, Srinivas

2009-08-01

To compare patterns of failure, late toxicities, and survival in locally advanced cervical cancer patients treated by either low-dose-rate (LDR) or conformal high-dose-rate (HDRc) brachytherapy as a part of curative radiotherapy. A retrospective comparative study of 217 advanced cervix cancer patients was conducted; 90 of these patients received LDR and 127 received HDRc brachytherapy. All patients were staged using International Federation of Gynecology and Obstetrics (FIGO) rules, had pretreatment magnetic resonance imaging (MRI), and were treated with concurrent cisplatin chemoradiotherapy. Both groups matched for FIGO stage, MRI tumor volume, and uterine invasion status. Local and pelvic failures were similar 12-13% and 14% both in both groups. Abdominal and systemic failures in LDR group were 21% and 24%, whereas corresponding failures in HDRc group were 20% and 24%. Sixty-eight percent (87/127) of patients treated by HDRc remained asymptomatic, whereas 42% (38/90) of patients were asymptomatic from the bowel and bladder symptoms after treatment with LDR. The 5-year OS rate was 60% (SE = 4%). The 5-year failure-free survival rate was 55% (SE = 3%). There was no significant difference between the groups. Image-guided HDRc planning led to a large decrease in late radiation effects in patients treated by HDRc. Patterns of failure and survival were similar in patients treated either by LDR or HDRc.

Comparative Study of LDR (Manchester System) and HDR Image-guided Conformal Brachytherapy of Cervical Cancer: Patterns of Failure, Late Complications, and Survival

International Nuclear Information System (INIS)

Narayan, Kailash; Dyk, Sylvia van; Bernshaw, David; Rajasooriyar, Chrishanthi; Kondalsamy-Chennakesavan, Srinivas

2009-01-01

Purpose: To compare patterns of failure, late toxicities, and survival in locally advanced cervical cancer patients treated by either low-dose-rate (LDR) or conformal high-dose-rate (HDRc) brachytherapy as a part of curative radiotherapy. Materials and Methods: A retrospective comparative study of 217 advanced cervix cancer patients was conducted; 90 of these patients received LDR and 127 received HDRc brachytherapy. All patients were staged using International Federation of Gynecology and Obstetrics (FIGO) rules, had pretreatment magnetic resonance imaging (MRI), and were treated with concurrent cisplatin chemoradiotherapy. Both groups matched for FIGO stage, MRI tumor volume, and uterine invasion status. Results: Local and pelvic failures were similar 12-13% and 14% both in both groups. Abdominal and systemic failures in LDR group were 21% and 24%, whereas corresponding failures in HDRc group were 20% and 24%. Sixty-eight percent (87/127) of patients treated by HDRc remained asymptomatic, whereas 42% (38/90) of patients were asymptomatic from the bowel and bladder symptoms after treatment with LDR. The 5-year OS rate was 60% (SE = 4%). The 5-year failure-free survival rate was 55% (SE = 3%). There was no significant difference between the groups. Conclusions: Image-guided HDRc planning led to a large decrease in late radiation effects in patients treated by HDRc. Patterns of failure and survival were similar in patients treated either by LDR or HDRc.

How to optimize therapeutic ratio in brachytherapy of head and neck squamous cell carcinoma?

International Nuclear Information System (INIS)

Mazeron, J.J.; Simon, J.M.; Hardiman, C.; Gerbaulet, A.

1998-01-01

Considerable experience has been accumulated with low dose rate (LDR) brachytherapy in the treatment of squamous cell carcinoma of the oral cavity and oropharynx, 4 cm or less in diameter. Recent analysis of large clinical series provided data indicating that modalities of LDR brachytherapy should be optimized in treating these tumours for increasing therapeutic ratio. LDR brachytherapy is now challenged by high dose rate (HDR) brachytherapy and pulsed dose rate (PDR) brachytherapy. Preliminary results obtained with the last two modalities are discussed in comparison with those achieved with LDR brachytherapy. (orig.)

Intra coronary brachytherapy

International Nuclear Information System (INIS)

Ghofourian, H.; Ghahremani, A.; Oliaie, A.; Taghizadeh Asl, M.

2002-01-01

Despite the initial promise of vasculopathy intervention restenosis- a consequence of the (normal) would healing process-has emerged as a major problem. Angiographic restenosis has been reported in 40-60% of patients after successful P TCA. The basic mechanism of restenosis, (acute recoil, negative remodeling and neo intimal hyperplasia), are only partially counteracted by endovascular prosthetic devices (s tents). The rate of in-s tent restenosis, which is primarily caused by neo intimal hyperplasia due to the (micro) trauma of the arterial wall by the s tent struts, has been reduced to 18-32%. Ionizing (beta or gamma) radiations has been established as a potent treatment for malignant disorders. In recent years, there has also been increasing interest among clinicians in the management of benign lesions with radiation. Over the past several years, there has been a growing body of evidence that endovascular brachytherapy has a major impact on the biology of the restenosis. It must be underlined that understanding the biology and pathophysiology of restenosis and assessing various treatment options should preferably be a team effort, with the three g races b eing interventional cardiologist, nuclear oncologist, and industrial partners. The vast amount of data in over 20000 patients from a wide range of randomized controlled trials, has shown that brachytherapy is the only effective treatment for in-s tent restenosis. We are learning more and more about how to improve brachytherapy. While the new coated s tents that we heard about today is fascinating and extremely promising, brachytherapy still has a very important place in difficult patients, such as those with total occlusions, osti al lesions, left main lesions, multivessel disease and diabetes. Regarding to above mentioned tips, we (a research team work, in the Nuclear Research Center Of the Atomic Energy Organization Of Iran), focused on synthesis and preparation of radioactive materials for use in I c-B T. We

Determining profile of dose distribution for PD-103 brachytherapy source

International Nuclear Information System (INIS)

Berkay, Camgoz; Mehmet, N. Kumru; Gultekin, Yegin

2006-01-01

Full text: Brachytherapy is a particular radiotherapy for cancer treatments. By destructing cancerous cells using radiation, the treatment proceeded. When alive tissues are subject it is hazardous to study experimental. For brachytherapy sources generally are studied as theoretical using computer simulation. General concept of the treatment is to locate the radioactive source into cancerous area of related tissue. In computer studies Monte Carlo mathematical method that is in principle based on random number generations, is used. Palladium radioisotope is LDR (Low radiation Dose Rate) source. Main radioactive material was coated with titanium cylinder with 3mm length, 0.25 mm radius. There are two parts of Pd-103 in the titanium cylinder. It is impossible to investigate differential effects come from two part as experimental. Because the source dimensions are small compared with measurement distances. So there is only simulation method. In dosimetric studies it is aimed to determine absorbed dose distribution in tissue as radial and angular. In nuclear physics it is obligation to use computer based methods for researchers. Radiation studies have hazards for scientist and people interacted with radiation. When hazard exceed over recommended limits or physical conditions are not suitable (long work time, non economical experiments, inadequate sensitivity of materials etc.) it is unavoidable to simulate works and experiments before practices of scientific methods in life. In medical area, usage of radiation is required computational work for cancer treatments. Some computational studies are routine in clinics and other studies have scientific development purposes. In brachytherapy studies there are significant differences between experimental measurements and theoretical (computer based) output data. Errors of data taken from experimental studies are larger than simulation values errors. In design of a new brachytherapy source it is important to consider detailed

TU-F-BRB-00: MRI-Based Motion Management for RT

International Nuclear Information System (INIS)

2015-01-01

The current clinical standard of organ respiratory imaging, 4D-CT, is fundamentally limited by poor soft-tissue contrast and imaging dose. These limitations are potential barriers to beneficial “4D” radiotherapy methods which optimize the target and OAR dose-volume considering breathing motion but rely on a robust motion characterization. Conversely, MRI imparts no known radiation risk and has excellent soft-tissue contrast. MRI-based motion management is therefore highly desirable and holds great promise to improve radiotherapy of moving cancers, particularly in the abdomen. Over the past decade, MRI techniques have improved significantly, making MR-based motion management clinically feasible. For example, cine MRI has high temporal resolution up to 10 f/s and has been used to track and/or characterize tumor motion, study correlation between external and internal motions. New MR technologies, such as 4D-MRI and MRI hybrid treatment machines (i.e. MR-linac or MR-Co60), have been recently developed. These technologies can lead to more accurate target volume determination and more precise radiation dose delivery via direct tumor gating or tracking. Despite all these promises, great challenges exist and the achievable clinical benefit of MRI-based tumor motion management has yet to be fully explored, much less realized. In this proposal, we will review novel MR-based motion management methods and technologies, the state-of-the-art concerning MRI development and clinical application and the barriers to more widespread adoption. Learning Objectives: Discuss the need of MR-based motion management for improving patient care in radiotherapy. Understand MR techniques for motion imaging and tumor motion characterization. Understand the current state of the art and future steps for clinical integration. Henry Ford Health System holds research agreements with Philips Healthcare. Research sponsored in part by a Henry Ford Health System Internal Mentored Grant

TU-F-BRB-00: MRI-Based Motion Management for RT

Energy Technology Data Exchange (ETDEWEB)

NONE

2015-06-15

The current clinical standard of organ respiratory imaging, 4D-CT, is fundamentally limited by poor soft-tissue contrast and imaging dose. These limitations are potential barriers to beneficial “4D” radiotherapy methods which optimize the target and OAR dose-volume considering breathing motion but rely on a robust motion characterization. Conversely, MRI imparts no known radiation risk and has excellent soft-tissue contrast. MRI-based motion management is therefore highly desirable and holds great promise to improve radiotherapy of moving cancers, particularly in the abdomen. Over the past decade, MRI techniques have improved significantly, making MR-based motion management clinically feasible. For example, cine MRI has high temporal resolution up to 10 f/s and has been used to track and/or characterize tumor motion, study correlation between external and internal motions. New MR technologies, such as 4D-MRI and MRI hybrid treatment machines (i.e. MR-linac or MR-Co60), have been recently developed. These technologies can lead to more accurate target volume determination and more precise radiation dose delivery via direct tumor gating or tracking. Despite all these promises, great challenges exist and the achievable clinical benefit of MRI-based tumor motion management has yet to be fully explored, much less realized. In this proposal, we will review novel MR-based motion management methods and technologies, the state-of-the-art concerning MRI development and clinical application and the barriers to more widespread adoption. Learning Objectives: Discuss the need of MR-based motion management for improving patient care in radiotherapy. Understand MR techniques for motion imaging and tumor motion characterization. Understand the current state of the art and future steps for clinical integration. Henry Ford Health System holds research agreements with Philips Healthcare. Research sponsored in part by a Henry Ford Health System Internal Mentored Grant.

Endobronchial brachytherapy: the Saint-Louis Hospital experience

International Nuclear Information System (INIS)

Hennequin, C.; Durdux, C.; Housset, M.; Maylin, C.; Tredaniel, J.; Zalcman, G.; Hirsch, A.; Dray, M.; Manoux, D.; Perret, M.

1997-01-01

During the evolution of lung cancer, bronchial obstruction is often noticed and is sometimes responsible for serious symptoms. Several methods of des-obstruction can be proposed, including brachytherapy. Materials and methods: One hundred forty-nine patients, presenting with endobronchial brachytherapy were included into the study. Seventy-three were treated with curative intent, 47 with palliative intent and 29 with a combination of external irradiation and brachytherapy. We usually delivered a series of two 7-Gy fractions (1 cm from the catheter), the treatment being repeated one, two or three times. Results: When all symptoms were taken into account, respiratory function improvement was present in 79% of the patients. Among the 132 tumors that could be evaluated via a new endoscopy 2 months after treatment, 64 (48.5%) were in complete histological remission. The median survival was 14.4 months for the patients treated with curative intent. Eleven massive hemoptyses and 13 radiation bronchitides were observed. Conclusion: These results confirm the feasibility and good results related to endobronchial brachytherapy, though controlled studies are needed to better define its place in the therapeutic strategy of bronchial carcinomas. (authors)

MRI-based N-staging in esophageal cancer

International Nuclear Information System (INIS)

Krupski, G.; Lorenzen, J.; Nicolas, V.; Adam, G.; Gawad, K.; Izbicki, J.R.

2002-01-01

Purpose: For planning the therapeutic strategies and estimating the prognosis in esophageal cancer, N-staging is very important. To date, MRI still is of minor importance as imaging modality of the mediastinum despite promising developments in the past, like ECG-gating or 'averaging' sequences, e.g. LOTA (Long-term averaging), which facilitate mediastinal and thoracic MR-imaging. In a prospective approach, the value of MRI based N-staging was examined with respect to LOTA-sequences. Material and Methods: Within from weeks prior to esophagectomy, standardized MRI of the esophagus was performed in 15 patients (10 squamous-cell-carcinomas and 5 adenocarcinomas) using a 1.5 T whole body scanner. Imaging quality was classified based on depiction of aortic wall or tracheal wall layers. Criteria for malignant infiltration were a diameter of more than 15 mm or a round appearance of a lymph node together with GD-DTPA enhancement. All data were blinded and separately read by two radiologists. The data of the study were compared with those from the pathological workup of the resected specimen. Results: MRI had a sensitivity of 100% and a specificity of 78% for lymph node metastases. Due to incomplete depiction of the celiac trunk (M1), nodal metastasis in a non-enlarged node was missed. Conclusion: With modern MRI, N-staging is almost as accurate as the gold standard endoscopic ultrasound and should particularly be used in patients not suited for an endoscopic ultrasound examination. (orig.) [de

Automation of brachytherapy planning based on RADPLAN system

International Nuclear Information System (INIS)

Costa, Helder Rodrigues da; Campos, Tarcisio P.R.

2000-01-01

RADPLAN is a software to automate the clinical planning of doses in brachytherapy managing the radionuclide source position and time. It intends to be a important tools to assist cancer treatment in the radiotherapy services. It evaluates the tridimensional isodoses for a set of radioactive sources implanted on tissue or placed inside a body cavity. RADPLAN allows visualization of virtual frames in which isodose curves overlap medical images produced in computerized tomography), X-ray and nuclear magnetic resonance equipment. In this work, the software function is explained and a hypothetic case of medical information management is presented, specifically illustrations of isodoses curves obtained for a spatial distribution of Ir 192 wires implanted in a breast. (author)

Demonstration of brachytherapy boost dose-response relationships in glioblastoma multiforme

International Nuclear Information System (INIS)

Sneed, Penny K.; Lamborn, Kathleen R.; Larson, David A.; Prados, Michael D.; Malec, Mary K.; McDermott, Michael W.; Weaver, Keith A.; Phillips, Theodore L.; Wara, William M.; Gutin, Philip H.

1996-01-01

Purpose: To evaluate brachytherapy dose-response relationships in adults with glioblastoma undergoing temporary 125 I implant boost after external beam radiotherapy. Methods and Materials: Since June 1987, orthogonal radiographs using a fiducial marker box have been used to verify brain implant source positions and generate dose-volume histograms at the University of California, San Francisco. For adults who underwent brachytherapy boost for glioblastoma from June 1987 through December 1992, tumor volumes were reoutlined to ensure consistency and dose-volume histograms were recalculated. Univariate and multivariate analyses of various patient and treatment parameters were performed evaluating for influence of dose on freedom from local failure (FFLF) and actuarial survival. Results: Of 102 implant boosts, 5 were excluded because computer plans were unavailable. For the remaining 97 patients, analyses with adjustment for known prognostic factors (age, KPS, extent of initial surgical resection) and prognostic factors identified on univariate testing (adjuvant chemotherapy) showed that higher minimum brachytherapy tumor dose was strongly associated with improved FFLF (p = 0.001). A quadratic relationship was found between total biological effective dose and survival, with a trend toward optimal survival probability at 47 Gy minimum brachytherapy tumor dose (corresponding to about 65 Gy to 95% of the tumor volume); survival decreased with lower or higher doses. Two patients expired and one requires hospice care because of brain necrosis after brachytherapy doses > 63 Gy to 95% of the tumor volume with 60 Gy to > 18 cm 3 of normal brain. Conclusion: Although higher minimum brachytherapy tumor dose was strongly associated with better local control, a brachytherapy boost dose > 50-60 Gy may result in life-threatening necrosis. We recommend careful conformation of the prescription isodose line to the contrast enhancing tumor volume, delivery of a minimum brachytherapy

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

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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

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

International Nuclear Information System (INIS)

Kumar, Rajiv; Belz, Jodi; Markovic, Stacey; Jadhav, Tej; Fowle, William; Niedre, Mark; Cormack, Robert; Makrigiorgos, Mike G.; Sridhar, Srinivas

2015-01-01

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

Brachytherapy in vulvar cancer: analysis of 18 patients

International Nuclear Information System (INIS)

Frezza, G.; Baldissera, A.; Bernardi, L.; Bunkheila, F.; Galuppi, A.; Salvi, F.

1996-01-01

INTRODUCTION: Vulvar cancer is a rather common neoplasm in elderly patients. Surgery, followed eventually by postoperative radiotherapy, is the treatment of choice. The results of exclusive radiotherapy (external beam irradiation and/or brachytherapy) are not well defined and in the recent literature only small series are reported. Radiotherapy however is the only therapeutic option in patients who are not fit for radical surgery. It is thus necessary to review its indications and its modalities. PATIENTS METHODS AND RESULTS: From 1990 to 1994 18 pts with a diagnosis of squamous cell carcinoma of the vulva have been submitted to brachytherapy. Age ranged from 60 to 92 years (mean age 76, 1 ys). 14 pts were treated at diagnosis (11 pts) or for recurrent disease after surgery (3 pts). In 8 of them brachytherapy (total dose 35-45 Gy, dose rate: 0,4-0,78 Gy/h) was preceded by external beam irradiation (Co60 or electron beam, 40-50 Gy to primary and inguinal nodes); 6 pts were treated with brachytherapy alone (58-60 Gy; dose rate 0,44-0,63 Gy/h). 4 pts underwent to brachytherapy alone for local recurrence after surgery and postoperative radiotherapy (total dose 45-60 Gy; dose rate 0,37-0,49 Gy/h). Brachytherapy was always performed with 192 Ir. Plastic tubes (2 to 5 lines) were used for single plane implantation of small exophytic lesions limited to the labia (8 cases); a perineal template (10 cases) was employed in lesions extended to the vaginal mucosa or involving the clitoris or the area of the perineum. (10(14)) pts treated at diagnosis are alive and free from local recurrence after 11-48 mos. 3 of them, treated with brachytherapy alone, have presented a nodal recurrence in the groin after 14, 15 and 27 mos. respectively. All of them are alive and free from disease after surgery and external radiotherapy. None of the pts treated for recurrent disease after surgery + external beam radiotherapy has achieved a local control. CONCLUSION: Brachytherapy alone or

SU-E-J-216: A Sequence Independent Approach for Quantification of MR Image Deformations From Brachytherapy Applicators

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Wieringen, N van; Heerden, L van; Gurney-Champion, O; Kesteren, Z van; Houweling, A; Pieters, B; Bel, A [Academic Medical Center, Amsterdam (Netherlands)

2015-06-15

Purpose: MRI is increasingly used as a single imaging modality for brachytherapy treatment planning. The presence of a brachytherapy applicator may cause distortions in the images, especially at higher field strengths. Our aim is to develop a procedure to quantify these distortions theoretically for any MR-sequence and to verify the estimated deformations for clinical sequences. Methods: Image distortions due to perturbation of the B0-field are proportional to the ratio of the induced frequency shift and the read-out bandwidth of the applied sequence. By reconstructing a frequency-shift map from the phase data from a multi-echo sequence, distortions can be calculated for any MR-sequence. Verification of this method for estimating distortions was performed by acquiring images with opposing read-out directions and consequently opposing distortions. The applicator shift can be determined by rigidly matching these images. Clinically, T2W-TSE-images are used for this purpose. For pre-clinical tests, EPI-sequences with narrow read-out bandwidth (19.5–47.5Hz), consequently large distortions, were added to the set of clinical MRsequences. To quantify deformations of the Utrecht Interstitial CT/MR applicator (Elekta Brachytherapy) on a Philips Ingenia 3T MRI, pre-clinical tests were performed in a phantom with the applicator in water, followed by clinical validation. Results: Deformations observed in the narrow bandwidth EPI-images were well predicted using the frequency-shift, the latter giving an overestimation up to 30%/up to 1 voxel. For clinically applied MR-sequences distortions were well below the voxel size. In patient setup distortions determined from the frequency-shift map were at sub-voxel level (<0.7mm). Using T2W-images larger distortions were found (1–2mm). This discrepancy was caused by patient movement between/during acquisition of the T2W-images with opposing read-out directions. Conclusion: Phantom experiments demonstrated the feasibility of a

Influence of boost technique (external beam radiotherapy or brachytherapy) on the outcome of patients with carcinoma of the base of the tongue

International Nuclear Information System (INIS)

Regueiro, C.A.; Millan, I.; Torre, A. de la; Valcarcel, F.J.; Magallon, R.; Fernandez, E.; Aragon, G.

1995-01-01

We reviewed 90 patients with squamous cell carcinoma of the base of the tongue. Fifty-three patients were treated with external beam radiotherapy alone (3 T1, 11 T2, 21 T3, and 18 T4 tumors) and thirty-seven patients were treated with external beam radiotherapy plus brachytherapy boost (4 T1, 15 T2, 11 T3, and 7 T4 tumors). For patients with T1, T2 and T3 primaries, the actuarial 3-year local relapse-free survival was 42% following external beam radiotherapy alone and 67% following external beam radiotherapy plus brachytherapy (p<0.05). The actuarial 3-year cause specific survival for these T-stages was 37% for patients treated with external beam radiotherapy alone and 53% for patients treated with external beam radiotherapy plus brachytherapy (p=0.1). In the Cox multivariate analyses restricted patients with T1, T2 and T3 staged tumors, treatment modality was the only predictor for local control but no influence on specific survival was found. The trend towards significant differences in specific survival found in the univariate comparison of both treatment modalities was probably due to the significantly higher number of N-positive patients treated with external beam radiotherapy alone. When all stages were included in the Cox analysis, low hemoglobin level, invasion of deep muscle, number of palpable nodes, and history of weight loss significantly influenced the outcome. Soft tissue necrosis occurred more frequently in patients treated with external beam radiotherapy plus brachytherapy (33% vs. 10%, p=0.52). (orig.)

Mucosal dose prescription in endobronchial brachytherapy: a study based on CT-dosimetry

International Nuclear Information System (INIS)

Lagerwaard, Frank J.; Murrer, Lars H.P.; Pan, Connie de; Roos, Martin; Senan, Suresh

2000-01-01

Purpose: To investigate the consequences of using different dose prescription methods for endobronchial brachytherapy (EB), both with and without the use of a centered applicator. Materials and Methods: A CT scan was performed during EB procedures in 13 patients after insertion of the lung applicator. A dosimetric analysis was subsequently performed in five of these patients using a 3D-brachytherapy treatment planning system (PLATO v13.3, Nucletron). Results: Dose prescription to the mucosa yields uniform dose distributions to the bronchial mucosa when a centrally positioned applicator is used. When non-centrally positioned applicators are used, mucosal dosing results in a significant underdosage to parts of the target volume. Due to the rapid dose fall-off in EB, dose prescription to the mucosa resulted in inadequate coverage of the outer portion of the bronchial wall and adjacent peribronchial space. When compared to mucosal dose prescription, prescription to the outer aspect of the bronchial wall appears to improve target coverage while limiting the hyperdose (i.e., 200%) volume. The diameters of the different bronchial segments, as determined by CT measurements in 13 patients, correlated well with calculated values based upon the tracheal diameter. Conclusions: Mucosal dose prescription should only be used in combination with centered EB applicators. Given the rapid dose fall-off in EB mucosal dose prescription should be used with caution in curative treatments where EB, without additional external radiotherapy, is used as the sole treatment modality. In curative EB, both improved target coverage and a limited hyperdose volume can be achieved by dose prescription to the outer aspect of the bronchial wall

Current Brachytherapy Quality Assurance Guidance: Does It Meet the Challenges of Emerging Image-Guided Technologies?

International Nuclear Information System (INIS)

Williamson, Jeffrey F.

2008-01-01

In the past decade, brachytherapy has shifted from the traditional surgical paradigm to more modern three-dimensional image-based planning and delivery approaches. The role of intraoperative and multimodality image-based planning is growing. Published American Association of Physicists in Medicine, American College of Radiology, European Society for Therapeutic Radiology and Oncology, and International Atomic Energy Agency quality assurance (QA) guidelines largely emphasize the QA of planning and delivery devices rather than processes. These protocols have been designed to verify compliance with major performance specifications and are not risk based. With some exceptions, complete and clinically practical guidance exists for sources, QA instrumentation, non-image-based planning systems, applicators, remote afterloading systems, dosimetry, and calibration. Updated guidance is needed for intraoperative imaging systems and image-based planning systems. For non-image-based brachytherapy, the American Association of Physicists in Medicine Task Group reports 56 and 59 provide reasonable guidance on procedure-specific process flow and QA. However, improved guidance is needed even for established procedures such as ultrasound-guided prostate implants. Adaptive replanning in brachytherapy faces unsolved problems similar to that of image-guided adaptive external beam radiotherapy

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.

Patterns of care for brachytherapy in Europe: Updated results

International Nuclear Information System (INIS)

Guedea, Ferran; Venselaar, Jack; Hoskin, Peter; Hellebust, Taran Paulsen; Peiffert, Didier; Londres, Bradley; Ventura, Montse; Mazeron, Jean-Jacques; Van Limbergen, Erik; Poetter, Richard; Kovacs, Gyorgy

2010-01-01

Objective: This descriptive survey evaluated brachytherapy (BT) practices and resources in the European area. This was a follow-up study to the original patterns of care for brachytherapy in Europe (PCBE). Materials and methods: A total of 1121 radiotherapy (RT) centres from 41 countries were asked to complete an online questionnaire on BT practices and resources. Countries with fewer than 50% of centres responding were excluded. Participating countries were divided into three groups based on gross domestic product (GDP); group I contained the countries with the highest GDP. Results: The response rate was 56% (633/1121 centres) with 30/41 countries (73%) meeting the inclusion criteria. Sixty percent of reporting centres provided brachytherapy. Responding centres treated an average of 138 (±10, 1 SD) patients with BT; in group I, the mean was 110/centre, an increase of 18% from 2002. CT-dosimetry increased to 61% of centres vs. 33% in 2002. HDR (high-dose rate) BT was the most commonly reported technique (65% of centres). Most BT interventions were for gynaecological tumors (59% of all cases), followed by prostate (17%), breast (9%), lung/bronchus (3%), and esophagus tumors(2%). Conclusion: Gynaecological BT remains the most common application, although both prostate and breast BT have increased. CT-based dosimetry has become increasingly common since 2002. The use of HDR and PDR (pulsed-dose rate) techniques has increased markedly, while both LDR and MDR (medium-dose rate) have declined.

High Dose-Rate Versus Low Dose-Rate Brachytherapy for Lip Cancer

International Nuclear Information System (INIS)

Ghadjar, Pirus; Bojaxhiu, Beat; Simcock, Mathew; Terribilini, Dario; Isaak, Bernhard; Gut, Philipp; Wolfensberger, Patrick; Brömme, Jens O.; Geretschläger, Andreas; Behrensmeier, Frank; Pica, Alessia; Aebersold, Daniel M.

2012-01-01

Purpose: To analyze the outcome after low-dose-rate (LDR) or high-dose-rate (HDR) brachytherapy for lip cancer. Methods and Materials: One hundred and three patients with newly diagnosed squamous cell carcinoma of the lip were treated between March 1985 and June 2009 either by HDR (n = 33) or LDR brachytherapy (n = 70). Sixty-eight patients received brachytherapy alone, and 35 received tumor excision followed by brachytherapy because of positive resection margins. Acute and late toxicity was assessed according to the Common Terminology Criteria for Adverse Events 3.0. Results: Median follow-up was 3.1 years (range, 0.3–23 years). Clinical and pathological variables did not differ significantly between groups. At 5 years, local recurrence-free survival, regional recurrence-free survival, and overall survival rates were 93%, 90%, and 77%. There was no significant difference for these endpoints when HDR was compared with LDR brachytherapy. Forty-two of 103 patients (41%) experienced acute Grade 2 and 57 of 103 patients (55%) experienced acute Grade 3 toxicity. Late Grade 1 toxicity was experienced by 34 of 103 patients (33%), and 5 of 103 patients (5%) experienced late Grade 2 toxicity; no Grade 3 late toxicity was observed. Acute and late toxicity rates were not significantly different between HDR and LDR brachytherapy. Conclusions: As treatment for lip cancer, HDR and LDR brachytherapy have comparable locoregional control and acute and late toxicity rates. HDR brachytherapy for lip cancer seems to be an effective treatment with acceptable toxicity.

MRI/TRUS fusion software-based targeted biopsy: the new standard of care?

Science.gov (United States)

Manfredi, M; Costa Moretti, T B; Emberton, M; Villers, A; Valerio, M

2015-09-01

The advent of multiparametric MRI has made it possible to change the way in which prostate biopsy is done, allowing to direct biopsies to suspicious lesions rather than randomly. The subject of this review relates to a computer-assisted strategy, the MRI/US fusion software-based targeted biopsy, and to its performance compared to the other sampling methods. Different devices with different methods to register MR images to live TRUS are currently in use to allow software-based targeted biopsy. Main clinical indications of MRI/US fusion software-based targeted biopsy are re-biopsy in men with persistent suspicious of prostate cancer after first negative standard biopsy and the follow-up of patients under active surveillance. Some studies have compared MRI/US fusion software-based targeted versus standard biopsy. In men at risk with MRI-suspicious lesion, targeted biopsy consistently detects more men with clinically significant disease as compared to standard biopsy; some studies have also shown decreased detection of insignificant disease. Only two studies directly compared MRI/US fusion software-based targeted biopsy with MRI/US fusion visual targeted biopsy, and the diagnostic ability seems to be in favor of the software approach. To date, no study comparing software-based targeted biopsy against in-bore MRI biopsy is available. The new software-based targeted approach seems to have the characteristics to be added in the standard pathway for achieving accurate risk stratification. Once reproducibility and cost-effectiveness will be verified, the actual issue will be to determine whether MRI/TRUS fusion software-based targeted biopsy represents anadd-on test or a replacement to standard TRUS biopsy.

Effect of photon energy spectrum on dosimetric parameters of brachytherapy sources.

Science.gov (United States)

Ghorbani, Mahdi; Mehrpouyan, Mohammad; Davenport, David; Ahmadi Moghaddas, Toktam

2016-06-01

The aim of this study is to quantify the influence of the photon energy spectrum of brachytherapy sources on task group No. 43 (TG-43) dosimetric parameters. Different photon spectra are used for a specific radionuclide in Monte Carlo simulations of brachytherapy sources. MCNPX code was used to simulate 125I, 103Pd, 169Yb, and 192Ir brachytherapy sources. Air kerma strength per activity, dose rate constant, radial dose function, and two dimensional (2D) anisotropy functions were calculated and isodose curves were plotted for three different photon energy spectra. The references for photon energy spectra were: published papers, Lawrence Berkeley National Laboratory (LBNL), and National Nuclear Data Center (NNDC). The data calculated by these photon energy spectra were compared. Dose rate constant values showed a maximum difference of 24.07% for 103Pd source with different photon energy spectra. Radial dose function values based on different spectra were relatively the same. 2D anisotropy function values showed minor differences in most of distances and angles. There was not any detectable difference between the isodose contours. Dosimetric parameters obtained with different photon spectra were relatively the same, however it is suggested that more accurate and updated photon energy spectra be used in Monte Carlo simulations. This would allow for calculation of reliable dosimetric data for source modeling and calculation in brachytherapy treatment planning systems.

Orbital rhabdomyosarcoma of the child: the role of PDR brachytherapy in eye preservation

International Nuclear Information System (INIS)

Kovacs, G.; Rochels, R.; Mehdorn, H.M.; Werner, J.; Wilhelm, R.; Kohr, P.; Kimmig, B. N.

1996-01-01

Material and Methods: There were four children (8-7-5 years and(15(12)) months old) with recurrent/primary embryonal rhabdomyosarcoma treated with curative intention by peroperative PDR boost brachytherapy in combination with radio-chemotherapy and/or surgery. PDR brachytherapy according to the Kiel protocol: daily five pulses, two hours each, with 1 Gy on the reference isodose which is usually 2-3 mm close to the applicator surface. CT simulation based conformal treatment planning was carried out in each case. The implant was done intraoperatively using the free-hand plastic tube method, after a macroscopically complete excision of the tumor. Due to treatment planning individual target volume, eye with N, opticus and bone structures, as well as the applicators and other regions of interest were visualized. Manual volume optimisation was practiced and natural volumen-dose histograms were analysed in 'classic' graphic mode as well as in a special colour coded three-dimensional visualization in cine mode on the screen. One child received, three months before the recurrence was operated, 50 Gy hyperfractionated external beam radiation (2 Gy fractions) and was irradiated with 20 Gy brachytherapy in four days. The second patient received ten days after 20 Gy brachytherapy 32 Gy hyperfractionated external beam radiation. The third child (external beam treatment outside of our clinic), received conventional fractionated irradiation with 1.6 Gy fraction dose instead of a prescribed hyperfractionated external beam therapy and her brachytherapy dose was 25 Gy. At the (15(12)) months old child with primary embryonal rhabdomyosarcoma we applied 20 Gy brachytherapy and 24 Gy hyperfractionated external beam irradiation. All patients received multidrug chemotherapy according to the German Study Protocol (CWS-91). Results: Follow-up is 34, 28, 22, and 6 months for recurrent embryonal rhabdomyosarcoma patients (stand February 96). We observed at 9 months one rhabdomyosarcoma

Independent technique of verifying high-dose rate (HDR) brachytherapy treatment plans

International Nuclear Information System (INIS)

Saw, Cheng B.; Korb, Leroy J.; Darnell, Brenda; Krishna, K. V.; Ulewicz, Dennis

1998-01-01

Purpose: An independent technique for verifying high-dose rate (HDR) brachytherapy treatment plans has been formulated and validated clinically. Methods and Materials: In HDR brachytherapy, dwell times at respective dwell positions are computed, using an optimization algorithm in a HDR treatment-planning system to deliver a specified dose to many target points simultaneously. Because of the variability of dwell times, concerns have been expressed regarding the ability of the algorithm to compute the correct dose. To address this concern, a commercially available low-dose rate (LDR) algorithm was used to compute the doses at defined distances, based on the dwell times obtained from the HDR treatment plans. The percent deviation between doses computed using the HDR and LDR algorithms were reviewed for HDR procedures performed over the last year. Results: In this retrospective study, the difference between computed doses using the HDR and LDR algorithms was found to be within 5% for about 80% of the HDR procedures. All of the reviewed procedures have dose differences of less than 10%. Conclusion: An independent technique for verifying HDR brachytherapy treatment plans has been validated based on clinical data. Provided both systems are available, this technique is universal in its applications and not limited to either a particular implant applicator, implant site, or implant type

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

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Tibor Major

2017-02-01

Full Text Available In the last decades, treatment planning for multicatheter interstitial breast brachytherapy has evolved considerably from fluoroscopy-based 2D to anatomy-based 3D planning. To plan the right positions of the catheters, ultrasound or computed tomography (CT imaging can be used, but the treatment plan is always based on postimplant CT images. With CT imaging, the 3D target volume can be defined more precisely and delineation of the organs at risk volumes is also possible. Consequently, parameters calculated from dose-volume histogram can be used for quantitative plan evaluation. 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 (manual, geometrical, on dose points, graphical are available to shape the dose distribution to the target volume, and these influence dose homogeneities to different extent. Currently, inverse optimization algorithms offer new possibilities to improve dose distributions further considering the requirements for dose coverage, dose homogeneity, and dose to organs at risk simultaneously and automatically. In this article, the evolvement of treatment planning for interstitial breast implants is reviewed, different forward optimization methods are discussed, and dose-volume parameters used for quantitative plan evaluation are described. Finally, some questions of the inverse optimization method are investigated and initial experiences of the authors are presented.

Urethral toxicity after LDR brachytherapy: experience in Japan.

Science.gov (United States)

Tanaka, Nobumichi; Asakawa, Isao; Hasegawa, Masatoshi; Fujimoto, Kiyohide

2015-01-01

Urinary toxicity is common after low-dose-rate (LDR) brachytherapy, and the resolution of urinary toxicity is a concern. In particular, urinary frequency is the most common adverse event among the urinary toxicities. We have previously reported that approximately 70% of patients experience urinary frequency during the first 6 months after seed implantation. Most urinary adverse events were classified as Grade 1, and Grade 2 or higher adverse events were rare. The incidence of urinary retention was approximately 2-4%. A high International Prostate Symptom Score before seed implantation was an independent predictor of acute urinary toxicity of Grade 2 or higher. Several previous reports from the United States also supported this trend. In Japan, LDR brachytherapy was legally approved in 2003. A nationwide prospective cohort study entitled Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 Seed Implantation was initiated in July 2005. It is an important issue to limit urinary toxicities in patients who undergo LDR brachytherapy. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

[Developments in brachytherapy].

Science.gov (United States)

Ikeda, H

1995-09-01

Brachytherapy is one of the ideal methods of radiotherapy because of the concentration of a high dose on the target. Recent developments, including induction of afterloading method, utilization of small-sized high-activity sources such as Iridium-192, and induction of high technology and computerization, have made for shortening of irradiation time and source handling, which has led to easier management of the patient during treatment. Dose distribution at high dose rate (HDR) is at least as good as that of low dose rate (LDR), and selection of fractionation and treatment time assures even greater biological effects on hypoxic tumor cells than LDR. Experience with HDR brachytherapy in uterine cervix cancer using Cobalt-60 during the past 20 years in this country has gradually been evaluated in U.S. and Europe. The indications for HDR treatment have extended to esophagus, bronchus, bile duct, brain, intraoperative placement of source guide, and perineal region using templates, as well as the conventional use for uterus, tongue and so on.

A Novel Marker Based Method to Teeth Alignment in MRI

Science.gov (United States)

Luukinen, Jean-Marc; Aalto, Daniel; Malinen, Jarmo; Niikuni, Naoko; Saunavaara, Jani; Jääsaari, Päivi; Ojalammi, Antti; Parkkola, Riitta; Soukka, Tero; Happonen, Risto-Pekka

2018-04-01

Magnetic resonance imaging (MRI) can precisely capture the anatomy of the vocal tract. However, the crowns of teeth are not visible in standard MRI scans. In this study, a marker-based teeth alignment method is presented and evaluated. Ten patients undergoing orthognathic surgery were enrolled. Supraglottal airways were imaged preoperatively using structural MRI. MRI visible markers were developed, and they were attached to maxillary teeth and corresponding locations on the dental casts. Repeated measurements of intermarker distances in MRI and in a replica model was compared using linear regression analysis. Dental cast MRI and corresponding caliper measurements did not differ significantly. In contrast, the marker locations in vivo differed somewhat from the dental cast measurements likely due to marker placement inaccuracies. The markers were clearly visible in MRI and allowed for dental models to be aligned to head and neck MRI scans.

Indication of brachytherapy of prostate with permanent implants

International Nuclear Information System (INIS)

Chauveinc, L.; Solignac, S.; Rosenwald, J.C.; Firmin, F.; Cosset, J.M.; Flam, T.; Thiounn, N.

2002-01-01

In the last decade, brachytherapy emerged as a particularly appealing new way of treating localized prostate cancer. Recently published 10-12 years biochemical control results appear to be superimposable to the best percentages achieved by surgery or conformal radiotherapy, with a small percentage of complications. This applied to severely patients. Only patients with T1/T2, PSA 60 g, hip mobility limitations, a urinary obstructive syndrome and previous trans-urethral resection lead to difficulties in technical implantation and therefore must be taken into account when discussing brachytherapy. In conclusion, for adequately selected patients, brachytherapy offers a particularly applied alternative to surgery and external radiotherapy, with satisfactory long term biochemical control rates and limited complications. (author)

Low dose rate Ir-192 interstitial brachytherapy for prostate cancer

Energy Technology Data Exchange (ETDEWEB)

Oki, Yosuke; Dokiya, Takushi; Yorozu, Atsunori; Suzuki, Takayuki; Saito, Shiro; Monma, Tetsuo; Ohki, Takahiro [National Tokyo Medical Center (Japan); Murai, Masaru; Kubo, Atsushi

2000-04-01

From December 1997 through January 1999, fifteen prostatic cancer patients were treated with low dose rate Ir-192 interstitial brachytherapy using TRUS and perineal template guidance without external radiotherapy. Up to now, as no apparent side effects were found, the safety of this treatment is suggested. In the future, in order to treat prostatic cancer patients with interstitial brachytherapy using I-125 or Pd-103, more investigation for this low dose rate Ir-192 interstitial brachytherapy is needed. (author)

Use of MRI in interventions in head and neck surgery; Die Nutzung der Magnetresonanztomographie bei Interventionen auf dem Gebiet der HNO-Heilkunde

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Schulz, T.; Schneider, J.P.; Schmidt, F.; Kahn, T. [Leipzig Univ. (Germany). Klinik und Poliklinik fuer Diagnostische Radiologie; Bootz, F.; Weber, A. [Leipzig Univ. (Germany). Klinik und Poliklinik fuer HNO-Heilkunde; Weidenbach, H. [Leipzig Univ. (Germany). Inst. fuer Pathologie; Heinke, W. [Leipzig Univ. (Germany). Klinik fuer Anaesthesie und Intensivmedizin; Koehler-Brock, A. [Leipzig Univ. (Germany). Klinik und Poliklinik fuer Strahlentherapie und Radioonkologie

2001-05-01

Presentation of new concepts and applications of MR-guided head and neck surgery are presented. Examples of diagnostic and therapeutic procedures such as evaluation of transseptal tumor biopsies, placement of afterloading catheters for brachytherapy, and microscopic surgery of paranasal sinuses in the open MRI are discussed. Material and Methods: 24 MRI-guided ENT-procedures (14 transsphenoidal biopsies, one transnasal biopsy, 6 placements of brachytherapy catheters, and 3 operations of the paranasal sinuses) were performed in an open 0.5 T MR system. Results: localisation and/or extension of all lesions as well as the placement of biopsy needles or catheters were determined with great precision during the interventions. Conclusions: surgical risk and postoperative morbidity are significantly reduced in MR-guided surgery of the petroclival region and the region of head and neck compared to other, conventional methods. Thus, interventional MRI-guidance optimizes minimal invasive surgery and catheter placement in difficult anatomical regions like the petroclival region. (orig.) [German] Vorstellung neuer Konzepte und Anwendungen der interventionellen MRT in der HNO-Heilkunde und Erlaeuterung am Beispiel diagnostischer und therapeutischer Interventionen. Evaluierung transseptaler Tumorbiopsien der petroclivalen Region, der Platzierung von Afterloadingsonden zur Brachytherapie und der Durchfuehrbarkeit mikroskopgestuetzter Nasennebenhoehlenoperationen. Material und Methoden: bei 24 Patienten wurden MR-gestuetzte Prozeduren im offenen MRT Signa SP/i durchgefuehrt (14 transsphenoidale Biopsien, eine transnasale Biopsie, 6 Afterloadingkatheter-Platzierungen und 3 Nasennebenhoehlenoperationen). Ergebnisse: bei allen Operationen war die Lokalisation des zu bioptierenden Tumors bzw. des Ausma paragraph es der Polyposis und seiner Umgebung moeglich. Sowohl die Biopsien als auch die Sondenplatzierungen und die Nasennebenhoehlenoperationen waren mit gro paragraph er Praezision

Time-driven activity-based costing of low-dose-rate and high-dose-rate brachytherapy for low-risk prostate cancer.

Science.gov (United States)

Ilg, Annette M; Laviana, Aaron A; Kamrava, Mitchell; Veruttipong, Darlene; Steinberg, Michael; Park, Sang-June; Burke, Michael A; Niedzwiecki, Douglas; Kupelian, Patrick A; Saigal, Christopher

Cost estimates through traditional hospital accounting systems are often arbitrary and ambiguous. We used time-driven activity-based costing (TDABC) to determine the true cost of low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy for prostate cancer and demonstrate opportunities for cost containment at an academic referral center. We implemented TDABC for patients treated with I-125, preplanned LDR and computed tomography based HDR brachytherapy with two implants from initial consultation through 12-month followup. We constructed detailed process maps for provision of both HDR and LDR. Personnel, space, equipment, and material costs of each step were identified and used to derive capacity cost rates, defined as price per minute. Each capacity cost rate was then multiplied by the relevant process time and products were summed to determine total cost of care. The calculated cost to deliver HDR was greater than LDR by $2,668.86 ($9,538 vs. $6,869). The first and second HDR treatment day cost $3,999.67 and $3,955.67, whereas LDR was delivered on one treatment day and cost $3,887.55. The greatest overall cost driver for both LDR and HDR was personnel at 65.6% ($4,506.82) and 67.0% ($6,387.27) of the total cost. After personnel costs, disposable materials contributed the second most for LDR ($1,920.66, 28.0%) and for HDR ($2,295.94, 24.0%). With TDABC, the true costs to deliver LDR and HDR from the health system perspective were derived. Analysis by physicians and hospital administrators regarding the cost of care afforded redesign opportunities including delivering HDR as one implant. Our work underscores the need to assess clinical outcomes to understand the true difference in value between these modalities. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Cost minimization analysis of high-dose-rate versus low-dose-rate brachytherapy in endometrial cancer

International Nuclear Information System (INIS)

Pinilla, James

1998-01-01

Purpose: Endometrial cancer is a common, usually curable malignancy whose treatment frequently involves low-dose-rate (LDR) or high-dose-rate (HDR) brachytherapy. These treatments involve substantial resource commitments and this is increasingly important. This paper presents a cost minimization analysis of HDR versus LDR brachytherapy in the treatment of endometrial cancer. Methods and Materials: The perspective of the analysis is that of the payor, in this case the Ministry of Health. One course of LDR treatment is compared to two courses of HDR treatment. The two alternatives are considered to be comparable with respect to local control, survival, and toxicities. Labor, overhead, and capital costs are accounted for and carefully measured. A 5% inflation rate is used where applicable. A univariate sensitivity analysis is performed. Results: The HDR regime is 22% less expensive compared to the LDR regime. This is $991.66 per patient or, based on the current workload of this department (30 patients per year) over the useful lifetime of the after loader, $297,498 over 10 years in 1997 dollars. Conclusion: HDR brachytherapy minimizes costs in the treatment of endometrial cancer relative to LDR brachytherapy. These results may be used by other centers to make rational decisions regarding brachytherapy equipment replacement or acquisition

A study on applying Ra needle interstitial brachytherapy for oral cancer

International Nuclear Information System (INIS)

Yoshida, Shunichi; Komiya, Yoshiaki; Uchida, Ikuhiro; Tashiro, Kazuyoshi

1999-01-01

To investigate applicability of Ra needle interstitial brachytherapy, 93 cases of oral squamous carcinoma were examined. The patients underwent Ra needle interstitial brachytherapy as thorough therapy in our hospital. The criteria of applying Ra needle interstitial brachytherapy was diameter of within 5 cm and depth within 2 cm of tumor size. Ra needle interstitial brachytherapy was applied to 82 cases of tongue, 10 cases of oral floor and one case of lower lip carcinomas. The local control rate was 92.5%, and secondary neck metastasis was 32.3% in all cases applied Ra needle interstitial brachytherapy. The results were not bad compared with surgical treatment. However, the 5-year cumulative survival rate was 64.9%, which was not good enough at the result to obtain a good local control rate and secondary neck metastasis rate. The result was relative to low treatment result of local recurrence cases with Ra needle interstitial brachytherapy. To improve the result, it is important to distinguish local recurrence from radioinduced ulcer, and to start early secondary treatment. The cases in which cervical lymph node metastasis was found as the first examination underwent neck dessection after Ra needle interstitial brachytherapy. The 5-year cumulative survival rate was 83.3% in N1 cases and 40.6% in N2 cases, and the result of N2 cases was poorer than N1 cases with a significant difference. The results indicate that a needle having a diameter of within 5 cm, depth of within 2 cm and less than N1 can be applied during Ra needle interstitial brachytherapy for complete cure of cancer. (author)

A survey of current clinical practice in permanent and temporary prostate brachytherapy: 2010 update.

Science.gov (United States)

Buyyounouski, Mark K; Davis, Brian J; Prestidge, Bradley R; Shanahan, Thomas G; Stock, Richard G; Grimm, Peter D; Demanes, D Jeffrey; Zaider, Marco; Horwitz, Eric M

2012-01-01

To help establish patterns of care and standards of care of interstitial permanent low-dose-rate (LDR) and temporary high-dose-rate brachytherapy for prostate cancer and to compare the results with a similar 1998 American Brachytherapy Society (ABS) survey. A comprehensive questionnaire intended to survey specific details of current clinical brachytherapy practice was provided to the participants of the seventh ABS Prostate Brachytherapy School. Responses were tabulated and descriptive statistics are reported. Sixty-five brachytherapy practitioners responded to the survey. Eighty-nine percent (89%) of respondents performed LDR and 49% perform high-dose-rate brachytherapy. The median number of years of experience for LDR brachytherapists increased from 5 to 10 years over the course of the 12 years since the preceding survey. Compared with the first ABS, a smaller proportion of respondents received formal brachytherapy residency training (43% vs. 56%) or formal "hands-on" brachytherapy training (15% vs. 63%). There has been a marked decline in the utilization of the Mick applicator (Mick Radio-Nuclear Instruments, Inc., Mount Vernon, NY, USA) (60% vs. 28%) and an increase in the use of stranded seeds (40% vs. 11%). Compliance with postimplant dosimetry was higher in the 2010 survey. This survey does suggest an evolution in the practice of LDR brachytherapy since 1998 and aids in identifying aspects that require further progress or investigation. ABS guidelines and other practice recommendations appear to impact the practice of brachytherapy. Copyright © 2012 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Efficacy of prophylactic single-dose therapy using fluoroquinolone for prostate brachytherapy

International Nuclear Information System (INIS)

Nomura, Takeo; Hirai, Kenichi; Yamasaki, Mutsushi; Inoue, Toru; Takahashi, Mika; Kawashima, Takayuki; Sato, Fuminori; Mimata, Hiromitsu

2012-01-01

There is little definitive evidence to guide the use of prophylactic antibiotics for prostate brachytherapy. The purpose of this study is to evaluate the incidence of postimplant infections in patients who receive antimicrobial prophylaxis with pazufloxacin (PZFX). A total of 84 patients who underwent prostate brachytherapy received a single intravenous dose of PZFX at 500 mg perioperatively for 1 day. No postimplant antibiotic medication was prescribed. Urinalysis, plasma white blood cell (WBC) count, and C reactive protein (CRP) levels were evaluated before the implantation, on the day after implantation, and on the 7th and 28th days after brachytherapy. None of the 84 patients (0.0%) developed a symptomatic urinary tract infection or had febrile infectious complications after brachytherapy. There were statistically significant elevations in the levels of erythrocytes, leukocytes, bacteria in urine, plasma WBC and CRP postoperatively, but these values did not exceed the normal range or were only slightly elevated on the day after brachytherapy (day 1) and on day 7. All laboratory examinations had returned to the normal range on day 28. Single-dose therapy with fluoroquinolone helps to prevent infections after prostate brachytherapy. (author)

SU-F-T-36: Dosimetric Comparison of Point Based Vs. Target Based Prescription for Intracavitary Brachytherapy in Cancer of the Cervix

Energy Technology Data Exchange (ETDEWEB)

Ashenafi, M; McDonald, D; Peng, J; Mart, C; Koch, N; Cooper, L; Vanek, K [Medical University of South Carolina, Charleston, SC (United States)

2016-06-15

Purpose: Improved patient imaging used for planning the treatment of cervical cancer with Tandem and Ovoid (T&O) Intracavitary high-dose-rate brachytherapy (HDR) now allows for 3D delineation of target volumes and organs-at-risk. However, historical data relies on the conventional point A-based planning technique. A comparative dosimetric study was performed by generating both target-based (TBP) and point-based (PBP) plans for ten clinical patients. Methods: Treatment plans created using Elekta Oncentra v. 4.3 for ten consecutive cervical cancer patients were analyzed. All patients were treated with HDR using the Utrecht T&O applicator. Both CT and MRI imaging modalities were utilized to delineate clinical target volume (CTV) and organs-at-risk (rectum, sigmoid, bladder, and small bowel). Point A (left and right), vaginal mucosa, and ICRU rectum and bladder points were defined on CT. Two plans were generated for each patient using two prescription methods (PBP and TBP). 7Gy was prescribed to each point A for each PBP plan and to the target D90% for each TBP plan. Target V90%, V100%, and V200% were evaluated. In addition, D0.1cc and D2cc were analyzed for each organ-at-risk. Differences were assessed for statistical significance (p<0.05) by use of Student’s t-test. Results: Target coverage was comparable for both planning methods, with each method providing adequate target coverage. TBP showed lower absolute dose to the target volume than PBP (D90% = 7.0Gy vs. 7.4Gy, p=0.028), (V200% = 10.9cc vs. 12.8cc, p=0.014), (ALeft = 6.4Gy vs. 7Gy, p=0.009), and (ARight = 6.4Gy vs. 7Gy, p=0.013). TBP also showed a statistically significant reduction in bladder, rectum, small bowel, and sigmoid doses compared to PBP. There was no statistically significant difference in vaginal mucosa or ICRU-defined rectum and bladder dose. Conclusion: Target based prescription resulted in substantially lower dose to delineated organs-at-risk compared to point based prescription, while

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.

CT-guided high-dose-rate brachytherapy of unresectable hepatocellular carcinoma

International Nuclear Information System (INIS)

Collettini, Federico; Schreiber, Nadja; Schnapauff, Dirk; Denecke, Timm; Hamm, Bernd; Gebauer, Bernhard; Wust, Peter; Schott, Eckart

2015-01-01

The purpose of the present study was to evaluate the clinical outcome of CT-guided high-dose-rate brachytherapy (CT-HDRBT) in patients with unresectable hepatocellular carcinoma (HCC). Over a 6-year period, 98 patients with 212 unresectable HCC underwent CT-HDRBT applying a 192 Ir source at our institution. Magnetic resonance imaging (MRI) follow-up was performed 6 weeks after the intervention and then every 3 months. The primary endpoint was local tumor control (LTC); secondary endpoints included progression-free survival (PFS) and overall survival (OS). Patients were available for MRI evaluation for a mean follow-up of 23.1 months (range 4-64 months; median 20 months). Mean tumor diameter was 5 cm (range 1.8-12 cm). Eighteen of 212 (8.5 %) tumors showed local progression after a mean LTC of 21.1 months. In all, 67 patients (68.4 %) experienced distant tumor progression. The mean PFS was 15.2 months. Forty-six patients died during the follow-up period. Median OS was 29.2 months. Actuarial 1-, 2-, and 3-year OS rates were 80, 62, and 46 %, respectively. CT-HDRBT is an effective therapy to attain local tumor control in patients with unresectable HCC. Prospective randomized studies comparing CT-HDRBT with the standard treatments like Radiofrequency ablation (RFA) and chemoembolization (TACE) are mandatory. (orig.) [de

Second salvage high-dose-rate brachytherapy for radiorecurrent prostate cancer

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Metha Maenhout

2017-04-01

Full Text Available Purpose : Salvage treatments for localized radiorecurrent prostate cancer can be performed safely when a focal and image guided approach is used. Due to the low toxicity, the opportunity exists to investigate a second salvage treatment when a second locally recurrent prostate cancer occurs. Here, we describe a second salvage treatment procedure of 4 patients. Material and methods : Four patients with a pathologically proven second local recurrence were treated in an outpatient magnetic resonance imaging (MRI-guided setting with a single fraction of 19 Gy focal high-dose-rate brachytherapy (HDR-BT. Delineation was performed using choline-PET-CT or a 68Ga-PSMA PET in combination with multiparametric 3 Tesla MRI in all four patients. Toxicity was measured using common toxicity criteria for adverse events (CTCAE version 4.0. Results : With a median follow-up of 12 months (range, 6-15, there were 2 patients with biochemical recurrence as defined by the Phoenix-definition. There were no patients with grade 3 or more toxicity. In all second salvage HDR-BT treatments, the constraints for rectum, bladder, and urethra were met. Median treatment volume (GTV was 4.8 cc (range, 1.9-6.6 cc. A median of 8 catheters (range, 6-9 were used, and the median dose to the treatment volume (GTV was a D95: 19.3 Gy (SD 15.5-19.4 Gy. Conclusions : Second focal salvage MRI-guided HDR-BT for a select group of patients with a second locally recurrent prostate cancer is feasible. There was no grade 3 or more acute toxicity for these four patients.

Energy spectrum based calculation of the half and the tenth value layers for brachytherapy sources using a semiempirical parametrized mass attenuation coefficient formulism

International Nuclear Information System (INIS)

Yue, Ning J.

2008-01-01

As different types of radionuclides (e.g., 131 Cs source) are introduced for clinical use in brachytherapy, the question is raised regarding whether a relatively simple method exists for the derivation of values of the half value layer (HVL) or the tenth value layer (TVL). For the radionuclide that has been clinically used for years, such as 125 I and 103 Pd, the sources have been manufactured and marketed by several vendors with different designs and structures. Because of the nature of emission of low energy photons for these radionuclides, energy spectra of the sources are very dependent on their individual designs. Though values of the HVL or the TVL in certain commonly used shielding materials are relatively small for these low energy photon emitting sources, the question remains how the variations in energy spectra affect the HVL (or TVL) values and whether these values can be calculated with a relatively simple method. A more fundamental question is whether a method can be established to derive the HVL (TVL) values for any brachytherapy sources and for different materials in a relatively straightforward fashion. This study was undertaken to answer these questions. Based on energy spectra, a well established semiempirical mass attenuation coefficient computing scheme was utilized to derive the HVL (TVL) values of different materials for different types of brachytherapy sources. The method presented in this study may be useful to estimate HVL (TVL) values of different materials for brachytherapy sources of different designs and containing different radionuclides

Monte Carlo simulations and radiation dosimetry measurements of 142Pr capillary tube-based radioactive implant (CTRI). A new structure for brachytherapy sources

International Nuclear Information System (INIS)

Bakht, M.K.; Haddadi, A.; Sadeghi, M.; Ahmadi, S.J.; Sadjadi, S.S.; Tenreiro, C.

2013-01-01

Previously, a promising β - -emitting praseodymium-142 glass seed was proposed for brachytherapy of prostate cancer. In accordance with the previous study, a 142 Pr capillary tube-based radioactive implant (CTRI) was suggested as a source with a new structure to enhance application of β - -emitting radioisotopes such as 142 Pr in brachytherapy. Praseodymium oxide powder was encapsulated in a glass capillary tube. Then, a thin and flexible fluorinated ethylene propylene Teflon layer sealed the capillary tube. The source was activated in the Tehran Research Reactor by the 141 Pr(n, γ) 142 Pr reaction. Measurements of the dosimetric parameters were performed using GafChromic radiochromic film. In addition, the dose rate distribution of 142 Pr CTRI was calculated by modeling 142 Pr source in a water phantom using Monte Carlo N-Particle Transport (MCNP5) Code. The active source was unreactive and did not leak in water. In comparison with the earlier proposed 142 Pr seed, the suggested source showed similar desirable dosimetric characteristics. Moreover, the 142 Pr CTRI production procedure may be technically and economically more feasible. The mass of praseodymium in CTRI structure could be greater than that of the 142 Pr glass seed; therefore, the required irradiation time and the neutron flux could be reduced. A 142 Pr CTRI was proposed for brachytherapy of prostate cancer. The dosimetric calculations by the experimental measurements and Monte Carlo simulation were performed to fulfill the requirements according to the American Association of Physicists in Medicine recommendations before the clinical use of new brachytherapy sources. The characteristics of the suggested source were compared with those of the previously proposed 142 Pr glass seed. (author)

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.)

Temporal relationship between prostate brachytherapy and the diagnosis of colorectal cancer

International Nuclear Information System (INIS)

Gutman, Sarah A.; Merrick, Gregory S.; Butler, Wayne M.; Wallner, Kent E.; Allen, Zachariah A.; Galbreath, Robert W.; Adamovich, Edward

2006-01-01

Purpose: To identify the location of pretreatment and posttreatment colorectal malignancies and posttreatment colorectal polyps in patients with clinically localized prostate cancer managed with brachytherapy. Methods and Materials: From April 1995 through July 2004, 1,351 consecutive patients underwent brachytherapy for clinical stage T1b-T3a (American Joint Committee on Cancer, 2002) prostate cancer. Supplemental external beam radiotherapy (XRT) was administered to 699 patients. The median follow-up was 4.6 years. Operative and pathology reports were reviewed for all patients with pretreatment and posttreatment colorectal cancer and posttreatment colorectal polyps. Multiple parameters were evaluated for the development of colorectal cancer or colorectal polyps. Results: Colorectal cancer was diagnosed in 23 and 25 patients before and after prostate brachytherapy, respectively. No differences were identified in the distribution of colorectal cancers either before or after treatment (3 and 4 rectal cancers in the pre- and postbrachytherapy cohorts). Thirty-five of the 48 colorectal cancers (73%) were diagnosed within 5 years of brachytherapy with a peak incidence 1 year after brachytherapy. One hundred ninety-two colorectal polyps were diagnosed after brachytherapy, 160 (83%) occurred within 4 years of brachytherapy, and only 27 (14%) were located in the rectum. In multivariate Cox regression analysis, prostate D 9 (minimum percentage of the dose covering 90% of the target volume) predicted for posttreatment colorectal cancer. Rectal polyps were most closely related to patient age and percent positive biopsies, whereas sigmoid/colon polyps were best predicted by patient age, planning volume, and supplemental XRT. Conclusions: Colorectal cancer was diagnosed with equal frequency before and after brachytherapy with comparable geographic distributions. In addition, the vast majority of postbrachytherapy colorectal polyps were located beyond the confines of the rectum

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)

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.

Radiation protection in brachytherapy

International Nuclear Information System (INIS)

Benitez, Manuel

1996-02-01

It covers technical procedures in medical applications for cancer treatment. Radiation protection principles in brachytherapy. Medical uses in therapy for Sr-90, Cs-137, Co-60, Ra-226, Ir-192, Au-198, Bi-214, Pb-214. (The author)

Prostate brachytherapy in Ghana: our initial experience

Directory of Open Access Journals (Sweden)

James Edward Mensah

2016-10-01

Full Text Available Purpose: This study presents the experience of a brachytherapy team in Ghana with a focus on technology transfer and outcome. The team was initially proctored by experienced physicians from Europe and South Africa. Material and methods : A total of 90 consecutive patients underwent either brachytherapy alone or brachytherapy in combination with external beam radiotherapy for prostate carcinoma between July 2008 and February 2014 at Korle Bu Teaching Hospital, Accra, Ghana. Patients were classified as low-risk, intermediate, and high-risk according to the National Comprehensive Cancer Network (NCCN criteria. All low-risk and some intermediate risk group patients were treated with seed implantation alone. Some intermediate and all high-risk group patients received brachytherapy combined with external beam radiotherapy. Results: The median patient age was 64.0 years (range 46-78 years. The median follow-up was 58 months (range 18-74 months. Twelve patients experienced biochemical failure including one patient who had evidence of metastatic disease and died of prostate cancer. Freedom from biochemical failure rates for low, intermediate, and high-risk cases were 95.4%, 90.9%, and 70.8%, respectively. Clinical parameters predictive of biochemical outcome included: clinical stage, Gleason score, and risk group. Pre-treatment prostate specific antigen (PSA was not a statistically significant predictor of biochemical failure. Sixty-nine patients (76.6% experienced grade 1 urinary symptoms in the form of frequency, urgency, and poor stream. These symptoms were mostly self-limiting. Four patients needed catheterization for urinary retention (grade 2. One patient developed a recto urethral fistula (grade 3 following banding for hemorrhoids. Conclusions : Our results compare favorably with those reported by other institutions with more extensive experience. We believe therefore that, interstitial permanent brachytherapy can be safely and effectively

Definitive radiotherapy based on HDR brachytherapy with iridium 192 in uterine cervix carcinoma: report on the Vienna University Hospital findings (1993-1997) compared to the preceding period in the context of ICRU 38 recommendations

International Nuclear Information System (INIS)

Potter, R.; Knocke, T.H.; Fellner, C.; Baldass, M.; Reinthaller, A.; Kucera, H.

2000-01-01

According to the reports described in the literature, fractionated HDR brachytherapy seems to represent one option for the primary treatment of cervical carcinoma. In order to render such treatment transparent and comparable for those interested in the field, we have attempted to report our recent experience obtained in Vienna from 1993-1997 using the terminology proposed by the ICRU report 38, focusing in particular on dose and volume reporting and a linear-quadratic model. Based on these parameters, a comparison with the preceding period in Vienna (LDR/HDR) has been made, with an attempt to correlate different methods and parameters with outcome. One hundred and eighty-nine patients (mean age 67 years) were treated with curative intent (stage la: 2,lb: 11, II a:11, IIb: 79, IIIa: 59, IVa: 5, IVb: 3 patients) using a combination of intra-cervical high-dose rate (HDR) brachytherapy (ring-tandem applicator) and a box technique for external-beam therapy (EBT: 48.6-50 Gy, linac 25 MV). Small tumors were treated with 5-6 fractions of 7 Gy at point A and 50 Gy EBT (25 Gy in the brachytherapy reference volume) which is iso-effective to 76-86 Gy at point A. Large tumors received 3-4 fractions of 7 Gy after 50 Gy EBT with open fields, which is iso-effective to 82-92 Gy ar point A. TRAK varied from mean 1.4 cGy (3 fractions) to 2.8 Gy (6 fractions) at one meter. 3-D treatment planning for brachytherapy was based on conventional X-rays and in 181/189 patients on computed tomography (CT) with the applicator in place. Computer-calculated volumes of the brachytherapy reference isodose (7 Gy/fraction) ranged from 46-155 ccm (mean 87 ccm); the respective mean hwt-volume (height x width x thickness) was 180 ccm. The 60 Gy HWT volumes (25 Gy from EBT) for the irradiation of small tumors ranged from 240 to 407 ccm (mean 337 ccm) and for larger tumors (50 Gy for EBT) from 452 to 785 ccm (mean 607 ccm). The beam dose for brachytherapy was 16.2 Gy (6.2-37.8 Gy) at the ICRU rectum

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

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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.

Advantages of high-dose rate (HDR) brachytherapy in treatment of prostate cancer

Science.gov (United States)

Molokov, A. A.; Vanina, E. A.; Tseluyko, S. S.

2017-09-01

One of the modern methods of preserving organs radiation treatment is brachytherapy. This article analyzes the results of prostate brachytherapy. These studies of the advantages of high dose brachytherapy lead to the conclusion that this method of radiation treatment for prostate cancer has a favorable advantage in comparison with remote sensing methods, and is competitive, preserving organs in comparison to surgical methods of treatment. The use of the method of polyfocal transperineal biopsy during the brachytherapy session provides information on the volumetric spread of prostate cancer and adjust the dosimetry plan taking into account the obtained data.

Underuse of brachytherapy for the treatment of dysphagia owing to esophageal cancer. An Italian survey.

Science.gov (United States)

Fuccio, Lorenzo; Guido, Alessandra; Hassan, Cesare; Frazzoni, Leonardo; Arcelli, Alessandra; Farioli, Andrea; Giaccherini, Lucia; Galuppi, Andrea; Mandolesi, Daniele; Cellini, Francesco; Mantello, Giovanna; Macchia, Gabriella; de Bortoli, Nicola; Repici, Alessandro; Valentini, Vincenzo; Bazzoli, Franco; Morganti, Alessio Giuseppe

2016-10-01

International guidelines strongly recommend brachytherapy as valid alternative or in addition to stenting in patients with dysphagia owing to esophageal cancer. However, for not well understood reasons, brachytherapy is definitively underused for the palliative treatment of malignant dysphagia. Aim of the current survey was to investigate the use of brachytherapy for the treatment of malignant dysphagia in Italy. A structured questionnaire was submitted to the 1510 members of the Italian Association of Radiation Oncologists (AIRO). These members refer to 177 centres of radiotherapy across Italy and in 68 (38.4%) of them brachytherapy is routinely performed. Of the 1510 invited members, 178 completed the survey (11.7%). The answers provided by the 178 participants allowed to get information on 40 out of 68 brachytherapy centres (58.8%). Seven out of 40 (17.5%) centres perform brachytherapy of the oesophagus, in 3 out of 40 (7.5%) centres brachytherapy represents the first line of treatment. The main reason why brachytherapy is not routinely performed is the lack of experience. Despite the strong recommendations of the international guidelines and the wide diffusion of brachytherapy centres across Italy, only very few of them routinely considered brachytherapy for the treatment of dysphagia due to esophageal cancer. Copyright © 2016 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Brachytherapy in head and neck cancers; Curietherapie des cancers de la sphere ORL

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Mazeron, J.J.; Noel, G.; Simon, J.M.; Racadot, S.; Jauffret, E. [Groupe Hospitalier la Pitie-Salpetriere, Centre des Tumeurs, 75 - Paris (France)

2003-02-01

Experience accumulated over several decades with radiation of Head and Neck tumours by irradiation has demonstrated the need for a high tumour dose to achieve local control. With external beam irradiation alone, it is difficult to spare adjacent normal tissues, resulting in undesirable late effects on the salivary glands; mandible, and muscles of mastication. Interstitial implantation is ideally suited to deliver a high dose limited to the volume of the primary tumor, thus minimizing sequels. A large experience has been accumulated with low dose rate (LDR) brachytherapy in treatment of carcinoma of oral cavity, oropharynx, and nasopharynx. Recent analysis of large clinical series provided data indicating that modalities of low dose rate brachytherapy should be optimized in treating these tumors for increasing therapeutic ratio. Low dose rate brachytherapy is now challenged by high dose rate (HDR) brachytherapy and pulsed dose rate (PDR) brachytherapy. Preliminary results obtained with these two last modalities are discussed regarding to those of low dose rate brachytherapy. (authors)

Image-robot coupling for the prostate brachytherapy

International Nuclear Information System (INIS)

Coelen, V.; Lartigau, E.; Merzouki, R.

2009-01-01

The results allows to contemplate a robot use in the prostate brachytherapy but equally in other applications such prostate biopsy. The tests to come are going to be directed towards on the use of a prostate phantom in order to calibrate the ultrasonography. thereafter, we contemplate the conception of an intelligent gripping system placed on the robot arm and allowing a good control in closed loop of the brachytherapy needle placement and allowing the setting up of an online monitoring. (N.C.)

Brachytherapy for Buccal Cancer: From Conventional Low Dose Rate (LDR) or Mold Technique to High Dose Rate Interstitial Brachytherapy (HDR-ISBT).

Science.gov (United States)

Kotsuma, Tadayuki; Yamazaki, Hideya; Masui, Koji; Yoshida, Ken; Shimizutani, Kimishige; Akiyama, Hironori; Murakami, Shumei; Isohashi, Fumiaki; Yoshioka, Yasuo; Ogawa, Kazuhiko; Tanaka, Eiichi

2017-12-01

To examine the effectiveness of newly-installed high-dose-rate interstitial brachytherapy (HDR-ISBT) for buccal cancer. We retrospectively reviewed 36 patients (25 men and 11 women) with buccal cancer treated with curative brachytherapy with or without external radiotherapy with a median follow-up of 99 months. A total of 15 HDR-ISBT (median 48 Gy/ 8 fractions, range=24-60 Gy) patients were compared to conventional 15 cases LDR-ISBT (70 Gy, range=42.8-110 Gy) and 7 molds techniques (15 Gy, range=9-74 Gy). A total of 31 patients also underwent external radiotherapy (30 Gy, range=24-48 Gy). They comprised of 3T1, 23 T2, 8 T3, 3 T4 including 11 node positive cases. HDR-ISBT provided 82% of local control rate at 5 years, whereas conventional brachytherapy showed 72% [p=0.44; LDR-ISBT (65%), mold therapy (85.7%)]. Patients with early lesions (T1-2 or stage I-II) showed better local control rates than those with advanced lesions (T3-4 or stage III-IV). Severe late grade 3 complications developed in two patients treated with LDR-ISBT and EBRT. There is no significant difference in toxicity grade ≤2 between conventional brachytherapy (5/15=33%) and HDR-ISBT (7/32=32%, p=0.92). HDR-ISBT achieved good and comparable local control rates to conventional brachytherapy without elevating the toxicity. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Changes in the micromorphology of the corneal subbasal nerve plexus in patients after plaque brachytherapy

International Nuclear Information System (INIS)

Zhivov, Andrey; Winter, Karsten; Peschel, Sabine; Stachs, Oliver; Wree, Andreas; Hildebrandt, Guido; Guthoff, Rudolf

2013-01-01

To quantify the development of radiation neuropathy in corneal subbasal nerve plexus (SNP) after plaque brachytherapy, and the subsequent regeneration of SNP micromorphology and corneal sensation. Nine eyes of 9 melanoma patients (ciliary body: 3, iris: 2, conjunctiva: 4) underwent brachytherapy (ruthenium-106 plaque, dose to tumour base: 523 ± 231 Gy). SNP micromorphology was assessed by in-vivo confocal microscopy. Using software developed in–house, pre-irradiation findings were compared with those obtained after 3 days, 1, 4 and 7 months, and related to radiation dose and corneal sensation. After 3 days nerve fibres were absent from the applicator zone and central cornea, and corneal sensation was abolished. The earliest regenerating fibres were seen at the one-month follow-up. By 4 months SNP structures had increased to one-third of pre-treatment status (based on nerve fibre density and nerve fibre count), and corneal sensation had returned to approximately two-thirds of pre-irradiation values. Regeneration of SNP and corneal sensation was nearly complete 7 months after plaque brachytherapy. The evaluation of SNP micromorphology and corneal sensation is a reliable and clinically useful method for assessing neuropathy after plaque brachytherapy. Radiation-induced neuropathy of corneal nerves develops quickly and is partly reversible within 7 months. The clinical impact of radiation-induced SNP damage is moderate

The use of tetrahedral mesh geometries in Monte Carlo simulation of applicator based brachytherapy dose distributions

International Nuclear Information System (INIS)

Fonseca, Gabriel Paiva; Yoriyaz, Hélio; Landry, Guillaume; White, Shane; Reniers, Brigitte; Verhaegen, Frank; D’Amours, Michel; Beaulieu, Luc

2014-01-01

Accounting for brachytherapy applicator attenuation is part of the recommendations from the recent report of AAPM Task Group 186. To do so, model based dose calculation algorithms require accurate modelling of the applicator geometry. This can be non-trivial in the case of irregularly shaped applicators such as the Fletcher Williamson gynaecological applicator or balloon applicators with possibly irregular shapes employed in accelerated partial breast irradiation (APBI) performed using electronic brachytherapy sources (EBS). While many of these applicators can be modelled using constructive solid geometry (CSG), the latter may be difficult and time-consuming. Alternatively, these complex geometries can be modelled using tessellated geometries such as tetrahedral meshes (mesh geometries (MG)). Recent versions of Monte Carlo (MC) codes Geant4 and MCNP6 allow for the use of MG. The goal of this work was to model a series of applicators relevant to brachytherapy using MG. Applicators designed for 192 Ir sources and 50 kV EBS were studied; a shielded vaginal applicator, a shielded Fletcher Williamson applicator and an APBI balloon applicator. All applicators were modelled in Geant4 and MCNP6 using MG and CSG for dose calculations. CSG derived dose distributions were considered as reference and used to validate MG models by comparing dose distribution ratios. In general agreement within 1% for the dose calculations was observed for all applicators between MG and CSG and between codes when considering volumes inside the 25% isodose surface. When compared to CSG, MG required longer computation times by a factor of at least 2 for MC simulations using the same code. MCNP6 calculation times were more than ten times shorter than Geant4 in some cases. In conclusion we presented methods allowing for high fidelity modelling with results equivalent to CSG. To the best of our knowledge MG offers the most accurate representation of an irregular APBI balloon applicator. (paper)

Automated calculation of point A coordinates for CT-based high-dose-rate brachytherapy of cervical cancer

Directory of Open Access Journals (Sweden)

Hyejoo Kang

2017-07-01

Full Text Available Purpose: The goal is to develop a stand-alone application, which automatically and consistently computes the coordinates of the dose calculation point recommended by the American Brachytherapy Society (i.e., point A based solely on the implanted applicator geometry for cervical cancer brachytherapy. Material and methods: The application calculates point A coordinates from the source dwell geometries in the computed tomography (CT scans, and outputs the 3D coordinates in the left and right directions. The algorithm was tested on 34 CT scans of 7 patients treated with high-dose-rate (HDR brachytherapy using tandem and ovoid applicators. A single experienced user retrospectively and manually inserted point A into each CT scan, whose coordinates were used as the “gold standard” for all comparisons. The gold standard was subtracted from the automatically calculated points, a second manual placement by the same experienced user, and the clinically used point coordinates inserted by multiple planners. Coordinate differences and corresponding variances were compared using nonparametric tests. Results: Automatically calculated, manually placed, and clinically used points agree with the gold standard to < 1 mm, 1 mm, 2 mm, respectively. When compared to the gold standard, the average and standard deviation of the 3D coordinate differences were 0.35 ± 0.14 mm from automatically calculated points, 0.38 ± 0.21 mm from the second manual placement, and 0.71 ± 0.44 mm from the clinically used point coordinates. Both the mean and standard deviations of the 3D coordinate differences were statistically significantly different from the gold standard, when point A was placed by multiple users (p < 0.05 but not when placed repeatedly by a single user or when calculated automatically. There were no statistical differences in doses, which agree to within 1-2% on average for all three groups. Conclusions: The study demonstrates that the automated algorithm

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

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}.

Water equivalency evaluation of PRESAGE® dosimeters for dosimetry of Cs-137 and Ir-192 brachytherapy sources

Science.gov (United States)

Gorjiara, Tina; Hill, Robin; Kuncic, Zdenka; Baldock, Clive

2010-11-01

A major challenge in brachytherapy dosimetry is the measurement of steep dose gradients. This can be achieved with a high spatial resolution three dimensional (3D) dosimeter. PRESAGE® is a polyurethane based dosimeter which is suitable for 3D dosimetry. Since an ideal dosimeter is radiologically water equivalent, we have investigated the relative dose response of three different PRESAGE® formulations, two with a lower chloride and bromide content than original one, for Cs-137 and Ir-192 brachytherapy sources. Doses were calculated using the EGSnrc Monte Carlo package. Our results indicate that PRESAGE® dosimeters are suitable for relative dose measurement of Cs-137 and Ir-192 brachytherapy sources and the lower halogen content PRESAGE® dosimeters are more water equivalent than the original formulation.

Graph-based network analysis of resting-state functional MRI

Directory of Open Access Journals (Sweden)

Jinhui Wang

2010-06-01

Full Text Available In the past decade, resting-state functional MRI (R-fMRI measures of brain activity have attracted considerable attention. Based on changes in the blood oxygen level-dependent signal, R-fMRI offers a novel way to assess the brain’s spontaneous or intrinsic (i.e., task-free activity with both high spatial and temporal resolutions. The properties of both the intra- and inter-regional connectivity of resting-state brain activity have been well documented, promoting our understanding of the brain as a complex network. Specifically, the topological organization of brain networks has been recently studied with graph theory. In this review, we will summarize the recent advances in graph-based brain network analyses of R-fMRI signals, both in typical and atypical populations. Application of these approaches to R-fMRI data has demonstrated non-trivial topological properties of functional networks in the human brain. Among these is the knowledge that the brain’s intrinsic activity is organized as a small-world, highly efficient network, with significant modularity and highly connected hub regions. These network properties have also been found to change throughout normal development, aging and in various pathological conditions. The literature reviewed here suggests that graph-based network analyses are capable of uncovering system-level changes associated with different processes in the resting brain, which could provide novel insights into the understanding of the underlying physiological mechanisms of brain function. We also highlight several potential research topics in the future.

Graph-based network analysis of resting-state functional MRI.

Science.gov (United States)

Wang, Jinhui; Zuo, Xinian; He, Yong

2010-01-01

In the past decade, resting-state functional MRI (R-fMRI) measures of brain activity have attracted considerable attention. Based on changes in the blood oxygen level-dependent signal, R-fMRI offers a novel way to assess the brain's spontaneous or intrinsic (i.e., task-free) activity with both high spatial and temporal resolutions. The properties of both the intra- and inter-regional connectivity of resting-state brain activity have been well documented, promoting our understanding of the brain as a complex network. Specifically, the topological organization of brain networks has been recently studied with graph theory. In this review, we will summarize the recent advances in graph-based brain network analyses of R-fMRI signals, both in typical and atypical populations. Application of these approaches to R-fMRI data has demonstrated non-trivial topological properties of functional networks in the human brain. Among these is the knowledge that the brain's intrinsic activity is organized as a small-world, highly efficient network, with significant modularity and highly connected hub regions. These network properties have also been found to change throughout normal development, aging, and in various pathological conditions. The literature reviewed here suggests that graph-based network analyses are capable of uncovering system-level changes associated with different processes in the resting brain, which could provide novel insights into the understanding of the underlying physiological mechanisms of brain function. We also highlight several potential research topics in the future.

Oncentra brachytherapy planning system.

Science.gov (United States)

Yang, Jack

2018-03-27

In modern cancer management, treatment planning has progressed as a contemporary tool with all the advances in computing power in recent years. One of the advanced planning tools uses 3-dimensional (3D) data sets for accurate dose distributions in patient prescription. Among these planning processes, brachytherapy has been a very important part of a successful cancer management program, offering clinical benefits with specific or combined treatments with external beam therapy. In this chapter, we mainly discussed the Elekta Oncentra planning system, which is the main treatment planning tool for high-dose rate (HDR) modality in our facility and in many other facilities in the United States. HDR is a technically advanced form of brachytherapy; a high-intensity radiation source (3.6 mm in length) is delivered with step motor in submillimeter precision under computer guidance directly into the tumor areas while minimizing injury to surrounding normal healthy tissue. Oncentra planning is the key component to generate a deliverable brachytherapy procedure, which is executed on the microSelectron V3 remote afterloader treatment system. Creating a highly conformal plan can be a time-consuming task. The development of Oncentra software (version 4.5.3) offers a variety of useful tools that facilitate many of the clinical challenging tasks for planning, such as contouring and image reconstruction, as well as rapid planning calculations with dose and dose volume histogram analysis. Oncentra Brachy module creates workflow and optimizes the planning accuracy for wide varieties of clinical HDR treatments, such as skin, gynecologic (GYN), breast, prostate, and many other applications. The treatment file can also be transferred to the afterloader control station for speedy delivery. The design concept, calculation algorithms, and optimization modules presented some key characteristics to plan and treat the patients effectively and accurately. The dose distribution and accuracy of

Brachytherapy for elderly patients with stage II tongue cancer

International Nuclear Information System (INIS)

Kimura, Tomoki; Hirokawa, Yutaka; Fujita, Minoru; Murakami, Yuji; Kenjo, Masahiro; Kaneyasu, Yuko; Ito, Katsuhide

2003-01-01

In treatment choices of stage II (T2N0M0) tongue cancer, brachytherapy is less invasive and superior in function preservation, therefore its role is more important in elderly patients. The aim of this study was to evaluate treatment results and morbidity of brachytherapy for elderly patients with stage II tongue cancer. Between 1980 and 2001, 198 patients with stage II tongue cancer were treated with brachytherapy at Hiroshima University Hospital. Patient ages ranged from 21 to 89 years old (median: 62 years old). Patients were divided into three groups as follows: 119 patients younger than 65 years old (Non-Elderly group), 53 patients between 65 and 75 years old (Junior Elderly group), and 26 patients 75 years or older (Senior Elderly group). Radiotherapy was performed in 101 patients with brachytherapy alone, and in 97 patients with brachytherapy and external radiotherapy. Chemotherapy was also performed in 77 patients. Follow-up period ranged from 4 to 243 months (median: 55 months). The 5-year local control rate was 85% in the Non-Elderly group, 85% in the Junior Elderly group and 81% in the Senior Elderly group. There was no significant difference among these groups. The 5-year cause-specific survival rate was 85%, 81% and 70% respectively. The Senior Elderly group showed poorer cause-specific survival rate than the other two groups (p=0.03). There was also a tendency of higher incidence of neck metastasis and low salvage rate by neck dissection in the Senior Elderly group. Although the Senior Elderly group showed poorer cause-specific survival rate, the local control rate was similar to those of the other two groups. Brachytherapy is an effective treatment option for elderly patients with stage II tongue cancer. (author)

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

International Nuclear Information System (INIS)

Haie-Meder, Christine; Siebert, Frank-Andre; Poetter, Richard

2011-01-01

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.

Medium-dose-rate brachytherapy of cancer of the cervix: preliminary results of a prospectively designed schedule based on the linear-quadratic model

International Nuclear Information System (INIS)

Leborgne, Felix; Fowler, Jack F.; Leborgne, Jose H.; Zubizarreta, Eduardo; Curochquin, Rene

1999-01-01

Purpose: To compare results and complications of our previous low-dose-rate (LDR) brachytherapy schedule for early-stage cancer of the cervix, with a prospectively designed medium-dose-rate (MDR) schedule, based on the linear-quadratic model (LQ). Methods and Materials: A combination of brachytherapy, external beam pelvic and parametrial irradiation was used in 102 consecutive Stage Ib-IIb LDR treated patients (1986-1990) and 42 equally staged MDR treated patients (1994-1996). The planned MDR schedule consisted of three insertions on three treatment days with six 8-Gy brachytherapy fractions to Point A, two on each treatment day with an interfraction interval of 6 hours, plus 18 Gy external whole pelvic dose, and followed by additional parametrial irradiation. The calculated biologically effective dose (BED) for tumor was 90 Gy 10 and for rectum below 125 Gy 3 . Results: In practice the MDR brachytherapy schedule achieved a tumor BED of 86 Gy 10 and a rectal BED of 101 Gy 3 . The latter was better than originally planned due to a reduction from 85% to 77% in the percentage of the mean dose to the rectum in relation to Point A. The mean overall treatment time was 10 days shorter for MDR in comparison with LDR. The 3-year actuarial central control for LDR and MDR was 97% and 98% (p = NS), respectively. The Grades 2 and 3 late complications (scale 0 to 3) were 1% and 2.4%, respectively for LDR (3-year) and MDR (2-year). Conclusions: LQ is a reliable tool for designing new schedules with altered fractionation and dose rates. The MDR schedule has proven to be an equivalent treatment schedule compared with LDR, with an additional advantage of having a shorter overall treatment time. The mean rectal BED Gy 3 was lower than expected

Palliative interstitial HDR brachytherapy for recurrent rectal cancer. Implantation techniques and results

International Nuclear Information System (INIS)

Kolotas, C.; Roeddiger, S.; Martin, T.; Tselis, N.; Baltas, D.; Zamboglou, N.; Strassmann, G.; Aebersold, D.M.

2003-01-01

Purpose: To report the methods and clinical results of CT-based interstitial high-dose-rate (HDR) brachytherapy procedures for the palliative treatment of recurrent rectal cancer. Patients and Methods: A total of 44 brachytherapy implants were performed in 38 patients. CT-guided catheter implants were performed in 34 patients under local anesthesia and sedation, and four patients were implanted intraoperatively. Of 40 CT-guided implants, 20 were done using metallic needles introduced via the sacrum and 20 were transperineal implants of plastic tubes in the presacral region. Postimplant CT scans were used for three-dimensional (3-D) conformal brachytherapy planning. Patients implanted with metallic needles were given a single fraction of 10-15 Gy using HDR 192 Ir, and those who received transperineal implants of plastic catheters were given fractionated brachytherapy, 5 Gy twice daily to a total dose of 30-40 Gy. The median tumor volume was 225 cm 3 with a range of 41-2,103 cm 3 . Results: After a median follow-up of 23.4 months, a total of 13/38 patients were alive. The median postbrachytherapy survival was 15 months with 18 of the 25 deaths due to distant metastases. Tumor response was as follows: 6/38 partial remission, 28/38 stable disease, and 4/38 local progression. A planning target volume (PTV) coverage > 85% was achieved in 42/44 implants. The treatment was well tolerated, and no acute complications were observed. One patient developed a fistula after 8 months. Pain relief was recorded in 34 patients (89.5%), and the median duration of this palliative effect was 5 months with a range of 1-13 months. Conclusions: Interstitial HDR brachytherapy is a valuable tool for the delivery of high doses and achieves effective palliation in recurrent rectal carcinoma. (orig.)

Palliative interstitial HDR brachytherapy for recurrent rectal cancer. Implantation techniques and results

Energy Technology Data Exchange (ETDEWEB)

Kolotas, C. [Dept. of Radiation Oncology, Offenbach Hospital, Offenbach (Germany); Dept. of Radio-Oncology, Univ. of Bern, Inselspital, Bern (Switzerland); Roeddiger, S.; Martin, T.; Tselis, N.; Baltas, D.; Zamboglou, N. [Dept. of Radiation Oncology, Offenbach Hospital, Offenbach (Germany); Strassmann, G. [Dept. of Radiotherapy, Univ. Hospital, Philipps Univ., Marburg (Germany); Aebersold, D.M. [Dept. of Radio-Oncology, Univ. of Bern, Inselspital, Bern (Switzerland)

2003-07-01

Purpose: To report the methods and clinical results of CT-based interstitial high-dose-rate (HDR) brachytherapy procedures for the palliative treatment of recurrent rectal cancer. Patients and Methods: A total of 44 brachytherapy implants were performed in 38 patients. CT-guided catheter implants were performed in 34 patients under local anesthesia and sedation, and four patients were implanted intraoperatively. Of 40 CT-guided implants, 20 were done using metallic needles introduced via the sacrum and 20 were transperineal implants of plastic tubes in the presacral region. Postimplant CT scans were used for three-dimensional (3-D) conformal brachytherapy planning. Patients implanted with metallic needles were given a single fraction of 10-15 Gy using HDR {sup 192}Ir, and those who received transperineal implants of plastic catheters were given fractionated brachytherapy, 5 Gy twice daily to a total dose of 30-40 Gy. The median tumor volume was 225 cm{sup 3} with a range of 41-2,103 cm{sup 3}. Results: After a median follow-up of 23.4 months, a total of 13/38 patients were alive. The median postbrachytherapy survival was 15 months with 18 of the 25 deaths due to distant metastases. Tumor response was as follows: 6/38 partial remission, 28/38 stable disease, and 4/38 local progression. A planning target volume (PTV) coverage > 85% was achieved in 42/44 implants. The treatment was well tolerated, and no acute complications were observed. One patient developed a fistula after 8 months. Pain relief was recorded in 34 patients (89.5%), and the median duration of this palliative effect was 5 months with a range of 1-13 months. Conclusions: Interstitial HDR brachytherapy is a valuable tool for the delivery of high doses and achieves effective palliation in recurrent rectal carcinoma. (orig.)

Current status of brachytherapy in cancer treatment – short overview

Directory of Open Access Journals (Sweden)

Janusz Skowronek

2017-12-01

Full Text Available Cancer incidence and mortality depend on a number of factors, including age, socio-economic status and geographical location, and its prevalence is growing around the world. Most of cancer treatments include external beam radiotherapy or brachytherapy. Brachytherapy, a type of radiotherapy with energy from radionuclides inserted directly into the tumor, is increasingly used in cancer treatment. For cervical and skin cancers, it has become a standard therapy for more than 100 years as well as an important part of the treatment guidelines for other malignancies, including head and neck, skin, breast, and prostate cancers. Compared to external beam radiotherapy, brachytherapy has the potential to deliver an ablative radiation dose over a short period of time directly to the altered tissue area with the advantage of a rapid fall-off in dose, and consequently, sparing of adjacent organs. As a result, the patient is able to complete the treatment earlier, and the risks of occurrence of another cancer are lower than in conventional radiotherapy treatment. Brachytherapy has increased its use as a radical or palliative treatment, and become more advanced with the spread of pulsed-dose-rate and high-dose-rate afterloading machines; the use of new 3D/4D planning systems has additionally improved the quality of the treatment. The aim of the present study was to present short summaries of current studies on brachytherapy for the most frequently diagnosed tumors. Data presented in this manuscript should help especially young physicians or physicists to explore and introduce brachytherapy in cancer treatments.

Iridium-192 sources production for brachytherapy use

International Nuclear Information System (INIS)

Rostelato, Maria Elisa Chuery Martins

1997-01-01

The incidence of cancer increases every year in Brazil and turns out to be one of the most important causes of mortality. Some of the patients are treated with brachytherapy, a form of lesion treatment which is based on the insertion of sources into tumors, in this particular case, activated iridium wires. During this process, the ionizing radiation efficiently destroys the malignant cells. These iridium wires have a nucleus made out of an iridium-platinum alloy 20-30/70-80 of 0,1 mm in diameter either coated by platinum or encased in a platinum tube. The technique consists in irradiating the wire in the reactor neutron flux in order to produce iridium-192. The linear activity goes from 1 mCi/cm to 4 mCi/cm and the basic characteristic, which is required, is the homogeneity of the activation along the wire. It should not present a dispersion exceeding 5% on a wire measuring 50 cm in length, 0.5 mm or 0.3 mm in diameter. Several experiments were carried out in order to define the activation parameters. Wires from different origins were analyzed. It was concluded that United States of America and France wires were found to be perfectly adequate for brachytherapy purposes and have therefore been sent to specialized hospitals and successfully applied to cancer patients. Considering that the major purpose of this work is to make this product more accessible in Brazil, at a cost reflecting the Brazilian reality, the IPEN is promoting the preparation of iridium-192 sources to be used in brachytherapy, on a national level. (author)

Surgery and postoperative brachytherapy for treatment of small volume uterine cervix cancer: an alternative to the standard association of utero vaginal brachytherapy + surgery

International Nuclear Information System (INIS)

Gallocher, O.; Thomas, L.; Pigneux, J.; Stocke, E.; Bussieres, E.; Avril, A.; Floquet, A.

2002-01-01

Purpose. -Evaluate the results of the treatment of small uterine cervix cancer with the association of surgery and postoperative vaginal brachytherapy, without unfavourable prognostic factors. Patients and methods. -After radical hysterectomy with lymphadenectomy, 29 women (mean age: 44 years) with carcinoma < 25 mm (26 stage IB1, 3 IIA, mean size: 15 mm) were treated by post-operative prophylactic vaginal brachytherapy using low dose rate. Ovarian transposition was performed at the surgical time in 14 young women (mean age 35 years). Results. - The actuarial specific survival rates at 5 and 10 years were 100% and 90% respectively, with a mean follow-up 75 months. Only one local recurrence was observed. The rate of grade 1 post-operative complication was 7%. The conservation rate of the ovarian function was 85% for young women. Conclusion. -Treatment of small volume uterine cervix cancer using first surgery and post-operative vaginal brachytherapy is a reliable therapeutic option. The results in terms of specific survival and complications are the same with those after standard association of preoperative utero-vaginal brachytherapy and surgery. (authors)

High dose rate brachytherapy for the palliation of malignant dysphagia

International Nuclear Information System (INIS)

Homs, Marjolein Y.V.; Eijkenboom, Wilhelmina M.H.; Coen, Veronique L.M.A.; Haringsma, Jelle; Blankenstein, Mark van; Kuipers, Ernst J.; Siersema, Peter D.

2003-01-01

Background and purpose: High dose rate (HDR) brachytherapy is a commonly used palliative treatment for esophageal carcinoma. We evaluated the outcome of HDR brachytherapy in patients with malignant dysphagia. Material and methods: A retrospective analysis over a 10-year period was performed of 149 patients treated with HDR brachytherapy, administered in one or two sessions, at a median dose of 15 Gy. Patients were evaluated for functional outcome, complications, recurrent dysphagia, and survival. Results: At 6 weeks after HDR brachytherapy, dysphagia scores had improved from a median of 3 to 2 (n=104; P<0.001), however, dysphagia had not improved in 51 (49%) patients. Procedure-related complications occurred in seven (5%) patients. Late complications, including fistula formation or bleeding, occurred in 11 (7%) patients. Twelve (8%) patients experienced minor retrosternal pain. Median survival of the patients was 160 days with a 1-year survival rate of 15%. Procedure-related mortality was 2%. At follow-up, 55 (37%) patients experienced recurrent dysphagia. In 34 (23%) patients a metal stent was placed to relieve persistent or recurrent dysphagia. Conclusion: HDR brachytherapy is a moderately effective treatment for the palliation of malignant dysphagia. The incidence of early major complications is low, however, persistent and recurrent dysphagia occur frequently, and require often additional treatment

Dose reduction in LDR brachytherapy by implanted prostate gold fiducial markers.

Science.gov (United States)

Landry, Guillaume; Reniers, Brigitte; Lutgens, Ludy; Murrer, Lars; Afsharpour, Hossein; de Haas-Kock, Danielle; Visser, Peter; van Gils, Francis; Verhaegen, Frank

2012-03-01

The dosimetric impact of gold fiducial markers (FM) implanted prior to external beam radiotherapy of prostate cancer on low dose rate (LDR) brachytherapy seed implants performed in the context of combined therapy was investigated. A virtual water phantom was designed containing a single FM. Single and multi source scenarios were investigated by performing Monte Carlo dose calculations, along with the influence of varying orientation and distance of the FM with respect to the sources. Three prostate cancer patients treated with LDR brachytherapy for a recurrence following external beam radiotherapy with implanted FM were studied as surrogate cases to combined therapy. FM and brachytherapy seeds were identified on post implant CT scans and Monte Carlo dose calculations were performed with and without FM. The dosimetric impact of the FM was evaluated by quantifying the amplitude of dose shadows and the volume of cold spots. D(90) was reported based on the post implant CT prostate contour. Large shadows are observed in the single source-FM scenarios. As expected from geometric considerations, the shadows are dependent on source-FM distance and orientation. Large dose reductions are observed at the distal side of FM, while at the proximal side a dose enhancement is observed. In multisource scenarios, the importance of shadows appears mitigated, although FM at the periphery of the seed distribution caused underdosage (LDR brachytherapy seed implant dose distributions. Therefore, reduced tumor control could be expected from FM implanted in tumors, although our results are too limited to draw conclusions regarding clinical significance.

Quantitative in vivo assessment of radiation injury of the liver using Gd-EOB-DTPA enhanced MRI: tolerance dose of small liver volumes

Directory of Open Access Journals (Sweden)

Pech Maciej

2011-04-01

Full Text Available Abstract Backround Hepatic radiation toxicity restricts irradiation of liver malignancies. Better knowledge of hepatic tolerance dose is favourable to gain higher safety and to optimize radiation regimes in radiotherapy of the liver. In this study we sought to determine the hepatic tolerance dose to small volume single fraction high dose rate irradiation. Materials and methods 23 liver metastases were treated by CT-guided interstitial brachytherapy. MRI was performed 3 days, 6, 12 and 24 weeks after therapy. MR-sequences were conducted with T1-w GRE enhanced by hepatocyte-targeted Gd-EOB-DTPA. All MRI data sets were merged with 3D-dosimetry data. The reviewer indicated the border of hypointensity on T1-w images (loss of hepatocyte function or hyperintensity on T2-w images (edema. Based on the volume data, a dose-volume-histogram was calculated. We estimated the threshold dose for edema or function loss as the D90, i.e. the dose achieved in at least 90% of the pseudolesion volume. Results At six weeks post brachytherapy, the hepatocyte function loss reached its maximum extending to the former 9.4Gy isosurface in median (i.e., ≥9.4Gy dose exposure led to hepatocyte dysfunction. After 12 and 24 weeks, the dysfunctional volume had decreased significantly to a median of 11.4Gy and 14Gy isosurface, respectively, as a result of repair mechanisms. Development of edema was maximal at six weeks post brachytherapy (9.2Gy isosurface in median, and regeneration led to a decrease of the isosurface to a median of 11.3Gy between 6 and 12 weeks. The dose exposure leading to hepatocyte dysfunction was not significantly different from the dose provoking edema. Conclusion Hepatic injury peaked 6 weeks after small volume irradiation. Ongoing repair was observed up to 6 months. Individual dose sensitivity may differ as demonstrated by a relatively high standard deviation of threshold values in our own as well as all other published data.

SU-F-T-50: Evaluation of Monte Carlo Simulations Performance for Pediatric Brachytherapy Dosimetry

Energy Technology Data Exchange (ETDEWEB)

Chatzipapas, C; Kagadis, G [University Patras, Rion, Ahaia (Greece); Papadimitroulas, P [BET Solutions, Athens, Attiki (Greece); Loudos, G [Technological Educational Institute of Athens, Egaleo, Attiki (Greece); Papanikolaou, N [University of Texas HSC SA, San Antonio, TX (United States)

2016-06-15

Purpose: Pediatric tumors are generally treated with multi-modal procedures. Brachytherapy can be used with pediatric tumors, especially given that in this patient population low toxicity on normal tissues is critical as is the suppression of the probability for late malignancies. Our goal is to validate the GATE toolkit on realistic brachytherapy applications, and evaluate brachytherapy plans on pediatrics for accurate dosimetry on sensitive and critical organs of interest. Methods: The GATE Monte Carlo (MC) toolkit was used. Two High Dose Rate (HDR) 192Ir brachytherapy sources were simulated (Nucletron mHDR-v1 and Varian VS2000), and fully validated using the AAPM and ESTRO protocols. A realistic brachytherapy plan was also simulated using the XCAT anthropomorphic computational model .The simulated data were compared to the clinical dose points. Finally, a 14 years old girl with vaginal rhabdomyosarcoma was modelled based on clinical procedures for the calculation of the absorbed dose per organ. Results: The MC simulations resulted in accurate dosimetry in terms of dose rate constant (Λ), radial dose gL(r) and anisotropy function F(r,θ) for both sources.The simulations were executed using ∼1010 number of primaries resulting in statistical uncertainties lower than 2%.The differences between the theoretical values and the simulated ones ranged from 0.01% up to 3.3%, with the largest discrepancy (6%) being observed in the dose rate constant calculation.The simulated DVH using an adult female XCAT model was also compared to a clinical one resulting in differences smaller than 5%. Finally, a realistic pediatric brachytherapy simulation was performed to evaluate the absorbed dose per organ and to calculate DVH with respect to heterogeneities of the human anatomy. Conclusion: GATE is a reliable tool for brachytherapy simulations both for source modeling and for dosimetry in anthropomorphic voxelized models. Our project aims to evaluate a variety of pediatric

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

International Nuclear Information System (INIS)

Todor, D.

2015-01-01

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

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

MO-E-BRD-03: Intra-Operative Breast Brachytherapy: Is One Stop Shopping Best?

International Nuclear Information System (INIS)

Libby, B.

2015-01-01

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

Definitive Brachytherapy for Kaposi's Sarcoma

International Nuclear Information System (INIS)

Williams, A.; Ezzell, G.; Zalupski, M.; Fontanesi, J.

1996-01-01

Purpose: To assess the efficacy and possible complications in patients diagnosed with Kaposi's sarcoma and treated with definitive brachytherapy. Methods and Materials: Between January, 1995 and December, 1995, four patients with Kaposi's sarcoma (KS) were treated with brachytherapy. Three patients, all with positive HIV status were treated using Iridium 192 (Ir-192) sources via a high-dose rate remote afterloader. One patient with endemic KS was treated using the application of catheters loaded with Californium 252. Eight sites were treated and included scalp, feet, nose, penis, hand, neck, and back. Dose rate for Ir-192 was 330cGy/fx to a total dose of 990cGy. The Californium was delivered as 100nGy/b.i.d. to a total dose of 900nGy. Follow-up as ranged from 2-6 months. Results: All four patients remain alive. Seven of eight sites have had complete clinical response and each patient has reported durable pain relief that has not subsided through last follow-up of 1/96. Two of eight sites, both treated with surface mold technique with Californium 252 developed moist desquamation. The remaining six sites did not demonstrate significant toxicity. Conclusion: Brachytherapy can offer Kaposi's sarcoma patients results that are equivalent to external beam radiation therapy, with minimal complications, a shorter treatment time and potential cost effectiveness

SU-F-J-157: Effect of Contouring Uncertainty in Post Implant Dosimetry of Low-Dose-Rate Prostate Permanent Seed Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Mashouf, S; Merino, T; Ravi, A; Morton, G; Song, W [Sunnybrook Health Sciences Center, Odette Cancer Centre, Toronto, ON (Canada); University of Toronto, Dept. of Radiation Oncology, Toronto, ON (Canada); Safigholi, H; Soliman, A [Sunnybrook Research Institute, Toronto, ON (Canada)

2016-06-15

Purpose: There is strong evidence relating post-implant dosimetry for low-dose-rate (LDR) prostate seed brachytherapy to local control rates. The delineation of the prostate on CT images, however, represents a challenge due to the lack of soft tissue contrast in order to identify the prostate borders. This study aims at quantifying the sensitivity of clinically relevant dosimetric parameters to uncertainty in the contouring of prostate. Methods: CT images, post-op plans and contours of a cohort of patients (n=43) (low risk=55.8%, intermediate risk=39.5%, high risk=4.7%), who had received prostate seed brachytherapy, were imported into MIM Symphony treatment planning system. The prostate contours in post-implant CT images were expanded/contracted uniformly for margins of ±1.00 mm, ±2.00 mm, ±3.00 mm, ±4.00 mm and ±5.00 mm. The values for V100 and D90 were extracted from Dose Volume Histograms for each contour and compared. Results: Significant changes were observed in the values of D90 and V100 as well as the number of suboptimal plans for expansion or contraction margins of only few millimeters. Evaluation of coverage based on D90 was found to be less sensitive to expansion errors compared to V100. D90 led to a lower number of implants incorrectly identified with insufficient coverage for expanded contours which increases the accuracy of post-implant QA using CT images compared to V100. Conclusion: In order to establish a successful post implant QA for LDR prostate seed brachytherapy, it is necessary to identify the low and high thresholds of important dose metrics of the target volume such as D90 and V100. Since these parameters are sensitive to target volume definition, accurate identification of prostate borders would help to improve accuracy and predictive value of the post-implant QA process. In this respect, use of imaging modalities such as MRI where prostate is well delineated should prove useful.

SU-F-J-157: Effect of Contouring Uncertainty in Post Implant Dosimetry of Low-Dose-Rate Prostate Permanent Seed Brachytherapy

International Nuclear Information System (INIS)

Mashouf, S; Merino, T; Ravi, A; Morton, G; Song, W; Safigholi, H; Soliman, A

2016-01-01

Purpose: There is strong evidence relating post-implant dosimetry for low-dose-rate (LDR) prostate seed brachytherapy to local control rates. The delineation of the prostate on CT images, however, represents a challenge due to the lack of soft tissue contrast in order to identify the prostate borders. This study aims at quantifying the sensitivity of clinically relevant dosimetric parameters to uncertainty in the contouring of prostate. Methods: CT images, post-op plans and contours of a cohort of patients (n=43) (low risk=55.8%, intermediate risk=39.5%, high risk=4.7%), who had received prostate seed brachytherapy, were imported into MIM Symphony treatment planning system. The prostate contours in post-implant CT images were expanded/contracted uniformly for margins of ±1.00 mm, ±2.00 mm, ±3.00 mm, ±4.00 mm and ±5.00 mm. The values for V100 and D90 were extracted from Dose Volume Histograms for each contour and compared. Results: Significant changes were observed in the values of D90 and V100 as well as the number of suboptimal plans for expansion or contraction margins of only few millimeters. Evaluation of coverage based on D90 was found to be less sensitive to expansion errors compared to V100. D90 led to a lower number of implants incorrectly identified with insufficient coverage for expanded contours which increases the accuracy of post-implant QA using CT images compared to V100. Conclusion: In order to establish a successful post implant QA for LDR prostate seed brachytherapy, it is necessary to identify the low and high thresholds of important dose metrics of the target volume such as D90 and V100. Since these parameters are sensitive to target volume definition, accurate identification of prostate borders would help to improve accuracy and predictive value of the post-implant QA process. In this respect, use of imaging modalities such as MRI where prostate is well delineated should prove useful.

Impact of pre-implant lower urinary tract symptoms on postoperative urinary morbidity after permanent prostate brachytherapy

International Nuclear Information System (INIS)

Teishima, Jun; Iwamoto, Hideo; Miyamoto, Katsutoshi; Shoji, Koichi; Masumoto, Hiroshi; Inoue, Shogo; Kobayashi, Kanao; Kajiwara, Mitsuru; Matsubara, Akio

2012-01-01

The objectives of this study was to assess the impact of baseline lower urinary tract symptoms on postoperative urinary morbidity in patients being treated for prostate cancer with 125-I permanent prostate brachytherapy. A total of 104 prostate cancer patients were enrolled in this study. Their urinary morbidity was followed up using the International Prostate Symptom Score and Expanded Prostate Cancer Index Composite for 12 months or more after permanent prostate brachytherapy. Patients were classified into two groups based on their baseline International Prostate Symptom Score: the low International Prostate Symptom Score group (score≤7) and the high International Prostate Symptom Score group (score≥8). Urinary morbidity was estimated in each group based on the results of the International Prostate Symptom Score and Expanded Prostate Cancer Index Composite measured before permanent prostate brachytherapy, and at 1, 3, 6, 9 and 12 months after the end of all radiation therapy. The overall mean total International Prostate Symptom Score, International Prostate Symptom Score quality of life score, and urinary-related scores for Expanded Prostate Cancer Index Composite were significantly worse at 1 month after the end of treatment, but they improved gradually after the treatment and recovered to the baseline level within 12 months. Even in the high-International Prostate Symptom Score group, the International Prostate Symptom Score and International Prostate Symptom Score Quality of Life score were significantly worse at 1-3 months after permanent prostate brachytherapy, and then recovered to the baseline level without prolongation. Although the urination-related Expanded Prostate Cancer Index Composite score in the high-International Prostate Symptom Score group was significantly worse at 1 month after permanent prostate brachytherapy in comparison with that in the low-International Prostate Symptom Score group, it recovered to the baseline level without

137Cs - Brachytherapy sources : a technology scenario

International Nuclear Information System (INIS)

Varma, R.N.

2001-01-01

Cancer has emerged as one of the major cause of morbidity and mortality all over the world. India houses world's second largest population and registers 4-5 lakhs new cancer cases every year. Cancer of cervix is most common form of malignancy among Indian women. Radiation therapy, especially intracavity brachytherapy in conjunction with other modalities like surgery, chemotherapy has been found to be highly effective for the management and control of cervical carcinoma at all stages. A technology has been developed indigenously for the fabrication of 137 Cs sources for brachytherapy applications

Directional interstitial brachytherapy from simulation to application

Science.gov (United States)

Lin, Liyong

Organs at risk (OAR) are sometimes adjacent to or embedded in or overlap with the clinical target volume (CTV) to be treated. The purpose of this PhD study is to develop directionally low energy gamma-emitting interstitial brachytherapy sources. These sources can be applied between OAR to selectively reduce hot spots in the OARs and normal tissues. The reduction of dose over undesired regions can expand patient eligibility or reduce toxicities for the treatment by conventional interstitial brachytherapy. This study covers the development of a directional source from design optimization to construction of the first prototype source. The Monte Carlo code MCNP was used to simulate the radiation transport for the designs of directional sources. We have made a special construction kit to assemble radioactive and gold-shield components precisely into D-shaped titanium containers of the first directional source. Directional sources have a similar dose distribution as conventional sources on the treated side but greatly reduced dose on the shielded side, with a sharp dose gradient between them. A three-dimensional dose deposition kernel for the 125I directional source has been calculated. Treatment plans can use both directional and conventional 125I sources at the same source strength for low-dose-rate (LDR) implants to optimize the dose distributions. For prostate tumors, directional 125I LDR brachytherapy can potentially reduce genitourinary and gastrointestinal toxicities and improve potency preservation for low risk patients. The combination of better dose distribution of directional implants and better therapeutic ratio between tumor response and late reactions enables a novel temporary LDR treatment, as opposed to permanent or high-dose-rate (HDR) brachytherapy for the intermediate risk T2b and high risk T2c tumors. Supplemental external-beam treatments can be shortened with a better brachytherapy boost for T3 tumors. In conclusion, we have successfully finished the

Contemporary Toxicity Profile of Breast Brachytherapy Versus External Beam Radiation After Lumpectomy for Breast Cancer

Energy Technology Data Exchange (ETDEWEB)

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); Smith, Benjamin D. [Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Shaitelman, Simona F. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Smith, Grace L., E-mail: glsmith@mdanderson.org [Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

2016-03-15

Purpose: We compared toxicities after brachytherapy versus external beam radiation therapy (EBRT) in contemporary breast cancer patients. Methods and Materials: Using MarketScan healthcare claims, we identified 64,112 women treated from 2003 to 2012 with lumpectomy followed by radiation (brachytherapy vs EBRT). Brachytherapy was further classified by multichannel versus single-channel applicator approach. We identified the risks and predictors of 1-year infectious and noninfectious postoperative adverse events using logistic regression and temporal trends using Cochran-Armitage tests. We estimated the 5-year Kaplan-Meier cumulative incidence of radiation-associated adverse events. Results: A total of 4522 (7.1%) patients received brachytherapy (50.2% multichannel vs 48.7% single-channel applicator). The overall risk of infectious adverse events was higher after brachytherapy than after EBRT (odds ratio [OR] = 1.21; 95% confidence interval [CI] 1.09-1.34, P<.001). However, over time, the frequency of infectious adverse events after brachytherapy decreased, from 17.3% in 2003 to 11.6% in 2012, and was stable after EBRT at 9.7%. Beyond 2007, there were no longer excess infections with brachytherapy (P=.97). The overall risk of noninfectious adverse events was higher after brachytherapy than after EBRT (OR=2.27; 95% CI 2.09-2.47, P<.0001). Over time, the frequency of noninfectious adverse events detected increased: after multichannel brachytherapy, from 9.1% in 2004 to 18.9% in 2012 (Ptrend = .64); single-channel brachytherapy, from 12.8% to 29.8% (Ptrend<.001); and EBRT, from 6.1% to 10.3% (Ptrend<.0001). The risk was significantly higher with single-channel than with multichannel brachytherapy (hazard ratio = 1.32; 95% CI 1.03-1.69, P=.03). Of noninfectious adverse events, 70.9% were seroma. Seroma significantly increased breast pain risk (P<.0001). Patients with underlying diabetes, cardiovascular disease, and treatment with chemotherapy had increased

Contemporary Toxicity Profile of Breast Brachytherapy Versus External Beam Radiation After Lumpectomy for Breast Cancer

International Nuclear Information System (INIS)

Huo, Jinhai; Giordano, Sharon H.; Smith, Benjamin D.; Shaitelman, Simona F.; Smith, Grace L.

2016-01-01

Purpose: We compared toxicities after brachytherapy versus external beam radiation therapy (EBRT) in contemporary breast cancer patients. Methods and Materials: Using MarketScan healthcare claims, we identified 64,112 women treated from 2003 to 2012 with lumpectomy followed by radiation (brachytherapy vs EBRT). Brachytherapy was further classified by multichannel versus single-channel applicator approach. We identified the risks and predictors of 1-year infectious and noninfectious postoperative adverse events using logistic regression and temporal trends using Cochran-Armitage tests. We estimated the 5-year Kaplan-Meier cumulative incidence of radiation-associated adverse events. Results: A total of 4522 (7.1%) patients received brachytherapy (50.2% multichannel vs 48.7% single-channel applicator). The overall risk of infectious adverse events was higher after brachytherapy than after EBRT (odds ratio [OR] = 1.21; 95% confidence interval [CI] 1.09-1.34, P<.001). However, over time, the frequency of infectious adverse events after brachytherapy decreased, from 17.3% in 2003 to 11.6% in 2012, and was stable after EBRT at 9.7%. Beyond 2007, there were no longer excess infections with brachytherapy (P=.97). The overall risk of noninfectious adverse events was higher after brachytherapy than after EBRT (OR=2.27; 95% CI 2.09-2.47, P<.0001). Over time, the frequency of noninfectious adverse events detected increased: after multichannel brachytherapy, from 9.1% in 2004 to 18.9% in 2012 (Ptrend = .64); single-channel brachytherapy, from 12.8% to 29.8% (Ptrend<.001); and EBRT, from 6.1% to 10.3% (Ptrend<.0001). The risk was significantly higher with single-channel than with multichannel brachytherapy (hazard ratio = 1.32; 95% CI 1.03-1.69, P=.03). Of noninfectious adverse events, 70.9% were seroma. Seroma significantly increased breast pain risk (P<.0001). Patients with underlying diabetes, cardiovascular disease, and treatment with chemotherapy had increased

Interstitial high-dose rate brachytherapy as boost for anal canal cancer

International Nuclear Information System (INIS)

Falk, Alexander Tuan; Claren, Audrey; Benezery, Karen; François, Eric; Gautier, Mathieu; Gerard, Jean-Pierre; Hannoun-Levi, Jean-Michel

2014-01-01

To assess clinical outcomes of patients treated with a high-dose rate brachytherapy boost for anal canal cancer (ACC). From August 2005 to February 2013, 28 patients presenting an ACC treated by split-course external beam radiotherapy (EBRT) and HDR brachytherapy with or without chemotherapy in a French regional cancer center in Nice were retrospectively analyzed. Median age was 60.6 years [34 – 83], 25 patients presented a squamous cell carcinoma and 3 an adenocarcinoma; 21 received chemotherapy. Median dose of EBRT was 45 Gy [43.2 – 52]. Median dose of HDR brachytherapy was 12 Gy [10 - 15] with a median duration of 2 days. Median overall treatment time was 63 days and median delay between EBRT and brachytherapy was 20 days. Two-year local relapse free, metastatic free, disease free and overall survivals were 83%, 81.9%, 71.8% and 87.7% respectively. Acute toxicities were frequent but not severe with mostly grade 1 toxicities: 37% of genito-urinary, 40.7% of gastro-intestinal and 3.7% of cutaneous toxicities. Late toxicities were mainly G1 (43.1%) and G2 (22%). Two-year colostomy-free survival was 75.1%, one patient had a definitive sphincter amputation. High-dose rate brachytherapy for anal canal carcinoma as boost represents a feasible technique compared to low or pulsed-dose rate brachytherapy. This technique remains an excellent approach to precisely boost the tumor in reducing the overall treatment time

Optimum plastic scintillator and optical fiber combination for brachytherapy dosimetry

International Nuclear Information System (INIS)

Arnfield, Mark R.; Gaballa, Hani E.; Zwicker, Robert D.; Islam, Quazi; Schmidt-Ullrich, Rupert

1995-01-01

Purpose/Objective: There have been several recent reports using plastic scintillators to measure dose in photon and electron beams. External beam measurements agreed well with standard ion chamber dosimetry. This was implemented by using two identical, parallel optical fibers with a small piece of plastic scintillator attached to one. We have constructed a similar device for application to brachytherapy. Brachytherapy dosimetry is a more difficult problem than external beam because of high dose gradients and widely ranging photon energies. Based on detailed spectral measurements, we have designed a dosimeter specifically to meet the unique, stringent needs of brachytherapy. Materials and Methods: The work consisted of two stages. In the first stage, we measured the optical spectra emitted by commercial plastic scintillators and silica core optical fibers in the presence of a 10 Curie iridium 192 HDR source. In the second stage, the spectral information was used to select an optimum combination of scintillator and fiber which were incorporated in the dosimeter. Equipment for the spectral measurements included a 0.1 meter monochromator with a sensitive photomultiplier (PMT) with flat response across the visible. The resolution of spectral scans was 4 nm. The dosimeter was constructed with a 1mm x 3mm piece of plastic scintillator bonded with optical cement to a 0.6 mm diameter silica core optical fiber. A second, identical optical fiber running alongside the first, with no scintillator attached, was used for background subtraction. Two PMTs with high sensitivity in the visible were used at the fiber distal ends. There was a space for an optical filter between the fiber and the PMTs, whose purpose is described below. The PMTs were connected to a differential pair whose output was transferred to a current source for measurement by a standard electrometer. Results: The scintillation spectra of six different types of silica core optical fibers in the presence of the

Precise MRI-based stereotaxic surgery in large animal models

DEFF Research Database (Denmark)

Glud, Andreas Nørgaard; Bech, Johannes; Tvilling, Laura

BACKGROUND: Stereotaxic neurosurgery in large animals is used widely in different sophisticated models, where precision is becoming more crucial as desired anatomical target regions are becoming smaller. Individually calculated coordinates are necessary in large animal models with cortical...... and subcortical anatomical differences. NEW METHOD: We present a convenient method to make an MRI-visible skull fiducial for 3D MRI-based stereotaxic procedures in larger experimental animals. Plastic screws were filled with either copper-sulphate solution or MRI-visible paste from a commercially available...... cranial head marker. The screw fiducials were inserted in the animal skulls and T1 weighted MRI was performed allowing identification of the inserted skull marker. RESULTS: Both types of fiducial markers were clearly visible on the MRÍs. This allows high precision in the stereotaxic space. COMPARISON...

Developing a Treatment Planning Software Based on TG-43U1 Formalism for Cs-137 LDR Brachytherapy.

Science.gov (United States)

Sina, Sedigheh; Faghihi, Reza; Soleimani Meigooni, Ali; Siavashpour, Zahra; Mosleh-Shirazi, Mohammad Amin

2013-08-01

The old Treatment Planning Systems (TPSs) used for intracavitary brachytherapy with Cs-137 Selectron source utilize traditional dose calculation methods, considering each source as a point source. Using such methods introduces significant errors in dose estimation. As of 1995, TG-43 is used as the main dose calculation formalism in treatment TPSs. The purpose of this study is to design and establish a treatment planning software for Cs-137 Solectron brachytherapy source, based on TG-43U1 formalism by applying the effects of the applicator and dummy spacers. Two softwares used for treatment planning of Cs-137 sources in Iran (STPS and PLATO), are based on old formalisms. The purpose of this work is to establish and develop a TPS for Selectron source based on TG-43 formalism. In this planning system, the dosimetry parameters of each pellet in different places inside applicators were obtained by MCNP4c code. Then the dose distribution around every combination of active and inactive pellets was obtained by summing the doses. The accuracy of this algorithm was checked by comparing its results for special combination of active and inactive pellets with MC simulations. Finally, the uncertainty of old dose calculation formalism was investigated by comparing the results of STPS and PLATO softwares with those obtained by the new algorithm. For a typical arrangement of 10 active pellets in the applicator, the percentage difference between doses obtained by the new algorithm at 1cm distance from the tip of the applicator and those obtained by old formalisms is about 30%, while the difference between the results of MCNP and the new algorithm is less than 5%. According to the results, the old dosimetry formalisms, overestimate the dose especially towards the applicator's tip. While the TG-43U1 based software perform the calculations more accurately.

Quality assurance of Vari-source high dose rate (HDR) brachytherapy- remote after loader and cost effectiveness of Vari-source HDR- brachytherapy: NORI, Islamabad experience

International Nuclear Information System (INIS)

Ahmad, N.; Mahmood, H.; Jafri, S.R.A.

2004-01-01

A quality control of Vari-Source high dose rate (HDR) remote after loading brachytherapy machine was carried out and the cost effectiveness of HDR brachytherapy machine was also evaluated considering the cost of ten Iridium-192 wire sources at Nuclear Medicine, Oncology and Radiotherapy Institute (NORI), Islamabad, Pakistan. A total number of 253 intracavitary insertions were done in 98 patients from October 1996 to May 2001. The results of the quality control tests performed during 1996 to 2001 were within the acceptable limits. The cost effectiveness of Vari-Source HDR brachytherapy machine was also evaluated. The average cost per patient was calculated as US$ 491. Small number of patients was treated as the machine was used for gynecologic malignancies only. The objective was to assess the quality control status of HDR brachytherapy machine on patient treatment day, source exchange day and periodic day (monthly basis). It was found that the cost per patient can be minimized if other type of cancer patients are also treated on Vari-Source HDR machine. (author)

Brachytherapy needle deflection evaluation and correction

International Nuclear Information System (INIS)

Wan Gang; Wei Zhouping; Gardi, Lori; Downey, Donal B.; Fenster, Aaron

2005-01-01

In prostate brachytherapy, an 18-gauge needle is used to implant radioactive seeds. This thin needle can be deflected from the preplanned trajectory in the prostate, potentially resulting in a suboptimum dose pattern and at times requiring repeated needle insertion to achieve optimal dosimetry. In this paper, we report on the evaluation of brachytherapy needle deflection and bending in test phantoms and two approaches to overcome the problem. First we tested the relationship between needle deflection and insertion depth as well as whether needle bending occurred. Targeting accuracy was tested by inserting a brachytherapy needle to target 16 points in chicken tissue phantoms. By implanting dummy seeds into chicken tissue phantoms under 3D ultrasound guidance, the overall accuracy of seed implantation was determined. We evaluated methods to overcome brachytherapy needle deflection with three different insertion methods: constant orientation, constant rotation, and orientation reversal at half of the insertion depth. Our results showed that needle deflection is linear with needle insertion depth, and that no noticeable bending occurs with needle insertion into the tissue and agar phantoms. A 3D principal component analysis was performed to obtain the population distribution of needle tip and seed position relative to the target positions. Our results showed that with the constant orientation insertion method, the mean needle targeting error was 2.8 mm and the mean seed implantation error was 2.9 mm. Using the constant rotation and orientation reversal at half insertion depth methods, the deflection error was reduced. The mean needle targeting errors were 0.8 and 1.2 mm for the constant rotation and orientation reversal methods, respectively, and the seed implantation errors were 0.9 and 1.5 mm for constant rotation insertion and orientation reversal methods, respectively

Erectile function after permanent prostate brachytherapy

International Nuclear Information System (INIS)

Merrick, Gregory S.; Butler, Wayne M.; Galbreath, Robert W.; Stipetich, Robin L.; Abel, Laurie J.; Lief, Jonathan H.

2002-01-01

Purpose: To determine the incidence of potency preservation after permanent prostate brachytherapy using a validated patient-administered questionnaire and to evaluate the effect of multiple clinical and treatment parameters on penile erectile function. Methods and Materials: Four hundred twenty-five patients underwent permanent prostate brachytherapy from April 1995 to October 1999. Two hundred nine patients who were potent before brachytherapy and who at the time of the survey were not receiving hormonal therapy were mailed the specific erectile questions of the International Index of Erectile Function (IIEF) questionnaire with a self-addressed stamped envelope. The questionnaire consisted of 5 questions, with a maximal score of 25. Of the 209 patients, 181 (87%) completed and returned the questionnaire. The mean and median follow-up was 40.4±14.9 and 40.6 months, respectively (range 19-75). Preimplant erectile function was assigned using a three-tiered scoring system (2 = erections always or nearly always sufficient for vaginal penetration; 1 = erections sufficient for vaginal penetration but considered suboptimal; 0 = the inability to obtain erections and/or erections inadequate for vaginal penetration). Postimplant potency was defined as an IIEF score ≥11. The clinical parameters evaluated for erectile function included patient age, preimplant potency, clinical T-stage, pretreatment prostate-specific antigen level, Gleason score, elapsed time after implantation, hypertension, diabetes mellitus, and tobacco consumption. Treatment parameters included radiation dose to the prostate gland, use of hormonal manipulation, use of supplemental external beam radiotherapy (EBRT), choice of isotope, prostate volume, and planning volume. The efficacy of sildenafil citrate in brachytherapy-induced erectile dysfunction (ED) was also evaluated. Results: Pretreatment erectile function scores of 2 and 1 were assigned to 125 and 56 patients, respectively. With a 6-year follow

Resting-State Functional Connectivity-Based Biomarkers and Functional MRI-Based Neurofeedback for Psychiatric Disorders: A Challenge for Developing Theranostic Biomarkers.

Science.gov (United States)

Yamada, Takashi; Hashimoto, Ryu-Ichiro; Yahata, Noriaki; Ichikawa, Naho; Yoshihara, Yujiro; Okamoto, Yasumasa; Kato, Nobumasa; Takahashi, Hidehiko; Kawato, Mitsuo

2017-10-01

Psychiatric research has been hampered by an explanatory gap between psychiatric symptoms and their neural underpinnings, which has resulted in poor treatment outcomes. This situation has prompted us to shift from symptom-based diagnosis to data-driven diagnosis, aiming to redefine psychiatric disorders as disorders of neural circuitry. Promising candidates for data-driven diagnosis include resting-state functional connectivity MRI (rs-fcMRI)-based biomarkers. Although biomarkers have been developed with the aim of diagnosing patients and predicting the efficacy of therapy, the focus has shifted to the identification of biomarkers that represent therapeutic targets, which would allow for more personalized treatment approaches. This type of biomarker (i.e., "theranostic biomarker") is expected to elucidate the disease mechanism of psychiatric conditions and to offer an individualized neural circuit-based therapeutic target based on the neural cause of a condition. To this end, researchers have developed rs-fcMRI-based biomarkers and investigated a causal relationship between potential biomarkers and disease-specific behavior using functional MRI (fMRI)-based neurofeedback on functional connectivity. In this review, we introduce a recent approach for creating a theranostic biomarker, which consists mainly of 2 parts: (1) developing an rs-fcMRI-based biomarker that can predict diagnosis and/or symptoms with high accuracy, and (2) the introduction of a proof-of-concept study investigating the relationship between normalizing the biomarker and symptom changes using fMRI-based neurofeedback. In parallel with the introduction of recent studies, we review rs-fcMRI-based biomarker and fMRI-based neurofeedback, focusing on the technological improvements and limitations associated with clinical use. © The Author 2017. Published by Oxford University Press on behalf of CINP.

Low-Dose-Rate Brachytherapy Versus Cryotherapy in Low- and Intermediate-Risk Prostate Cancer

International Nuclear Information System (INIS)

Gestaut, Matthew M.; Cai, Wendi; Vyas, Shilpa; Patel, Belur J.; Hasan, Salman A.; MunozMaldonado, Yolanda; Deb, Niloyjyoti; Swanson, Gregory

2017-01-01

Purpose: Cryotherapy and brachytherapy are definitive local treatment options for low- to intermediate-risk prostate cancer. There are both prospective and retrospective data for brachytherapy, but the use of cryotherapy has been limited primarily to single-institution retrospective studies. Currently, no published evidence has compared low-dose-rate brachytherapy versus cryotherapy. Methods and Materials: Institutional review board approval was obtained to conduct a retrospective chart review of consecutive patients treated at our institution from 1990 to 2012. For inclusion, patients must have received a prostate cancer diagnosis and have been considered to have low- to intermediate-risk disease according to the National Comprehensive Cancer Network criteria. All patients received brachytherapy or cryotherapy treatment. Disease specifics and failure details were collected for all patients. Failure was defined as prostate-specific antigen nadir +2 ng/mL. Results: A total of 359 patients were analyzed. The groups comprised 50 low-risk cryotherapy (LRC), 92 intermediate-risk cryotherapy (IRC), 133 low-risk brachytherapy (LRB), and 84 intermediate-risk brachytherapy (IRB) patients. The median prostate-specific antigen follow-up periods were 85.6 months (LRC), 59.2 months (IRC), 74.9 months (LRB), and 59.8 months (IRB). The 5-year biochemical progression–free survival (bPFS) rate was 57.9% in the cryotherapy group versus 89.6% in the brachytherapy group (P<.0001). The 5-year bPFS rate was 70.0% (LRC), 51.4% (IRC), 89.4% (LRB), and 89.7% (IRB). The bPFS rate was significantly different between brachytherapy and cryotherapy for low- and intermediate-risk groups (P<.05). The mean nadir temperature reached for cryotherapy patients was −35°C (range, −96°C to −6°C). Cryotherapy used a median of 2 freeze-thaw cycles (range, 2-4 freeze-thaw cycles). Conclusions: Results from this study suggest that cryotherapy is inferior to brachytherapy for patients with

Low-Dose-Rate Brachytherapy Versus Cryotherapy in Low- and Intermediate-Risk Prostate Cancer

Energy Technology Data Exchange (ETDEWEB)

Gestaut, Matthew M., E-mail: Matthew.Gestaut@BSWHealth.org [Department of Radiation Oncology, Baylor Scott and White Memorial Hospital, Texas A& M University School of Medicine, Temple, Texas (United States); Cai, Wendi [Department of Biostatistics, Baylor Scott and White Health, Temple, Texas (United States); Vyas, Shilpa [Department of Radiation Oncology, Swedish Cancer Institute, Seattle, Washington (United States); Patel, Belur J. [Department of Urology, Baylor Scott and White Memorial Hospital, Texas A& M University School of Medicine, Temple, Texas (United States); Hasan, Salman A. [Department of Radiation Oncology, Baylor Scott and White Memorial Hospital, Texas A& M University School of Medicine, Temple, Texas (United States); MunozMaldonado, Yolanda [Department of Biostatistics, Baylor Scott and White Health, Temple, Texas (United States); Deb, Niloyjyoti; Swanson, Gregory [Department of Radiation Oncology, Baylor Scott and White Memorial Hospital, Texas A& M University School of Medicine, Temple, Texas (United States)

2017-05-01

Purpose: Cryotherapy and brachytherapy are definitive local treatment options for low- to intermediate-risk prostate cancer. There are both prospective and retrospective data for brachytherapy, but the use of cryotherapy has been limited primarily to single-institution retrospective studies. Currently, no published evidence has compared low-dose-rate brachytherapy versus cryotherapy. Methods and Materials: Institutional review board approval was obtained to conduct a retrospective chart review of consecutive patients treated at our institution from 1990 to 2012. For inclusion, patients must have received a prostate cancer diagnosis and have been considered to have low- to intermediate-risk disease according to the National Comprehensive Cancer Network criteria. All patients received brachytherapy or cryotherapy treatment. Disease specifics and failure details were collected for all patients. Failure was defined as prostate-specific antigen nadir +2 ng/mL. Results: A total of 359 patients were analyzed. The groups comprised 50 low-risk cryotherapy (LRC), 92 intermediate-risk cryotherapy (IRC), 133 low-risk brachytherapy (LRB), and 84 intermediate-risk brachytherapy (IRB) patients. The median prostate-specific antigen follow-up periods were 85.6 months (LRC), 59.2 months (IRC), 74.9 months (LRB), and 59.8 months (IRB). The 5-year biochemical progression–free survival (bPFS) rate was 57.9% in the cryotherapy group versus 89.6% in the brachytherapy group (P<.0001). The 5-year bPFS rate was 70.0% (LRC), 51.4% (IRC), 89.4% (LRB), and 89.7% (IRB). The bPFS rate was significantly different between brachytherapy and cryotherapy for low- and intermediate-risk groups (P<.05). The mean nadir temperature reached for cryotherapy patients was −35°C (range, −96°C to −6°C). Cryotherapy used a median of 2 freeze-thaw cycles (range, 2-4 freeze-thaw cycles). Conclusions: Results from this study suggest that cryotherapy is inferior to brachytherapy for patients with