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.

Automated treatment planning engine for prostate seed implant brachytherapy

International Nuclear Information System (INIS)

Yu Yan; Zhang, J.B.Y.; Brasacchio, Ralph A.; Okunieff, Paul G.; Rubens, Deborah J.; Strang, John G.; Soni, Arvind; Messing, Edward M.

1999-01-01

Purpose: To develop a computer-intelligent planning engine for automated treatment planning and optimization of ultrasound- and template-guided prostate seed implants. Methods and Materials: The genetic algorithm was modified to reflect the 2D nature of the implantation template. A multi-objective decision scheme was used to rank competing solutions, taking into account dose uniformity and conformity to the planning target volume (PTV), dose-sparing of the urethra and the rectum, and the sensitivity of the resulting dosimetry to seed misplacement. Optimized treatment plans were evaluated using selected dosimetric quantifiers, dose-volume histogram (DVH), and sensitivity analysis based on simulated seed placement errors. These dosimetric planning components were integrated into the Prostate Implant Planning Engine for Radiotherapy (PIPER). Results: PIPER has been used to produce a variety of plans for prostate seed implants. In general, maximization of the minimum peripheral dose (mPD) for given implanted total source strength tended to produce peripherally weighted seed patterns. Minimization of the urethral dose further reduced the loading in the central region of the PTV. Isodose conformity to the PTV was achieved when the set of objectives did not reflect seed positioning uncertainties; the corresponding optimal plan generally required fewer seeds and higher source strength per seed compared to the manual planning experience. When seed placement uncertainties were introduced into the set of treatment planning objectives, the optimal plan tended to reach a compromise between the preplanned outcome and the likelihood of retaining the preferred outcome after implantation. The reduction in the volatility of such seed configurations optimized under uncertainty was verified by sensitivity studies. Conclusion: An automated treatment planning engine incorporating real-time sensitivity analysis was found to be a useful tool in dosimetric planning for prostate

Automated planning volume definition in soft-tissue sarcoma adjuvant brachytherapy

International Nuclear Information System (INIS)

Lee, Eva K.; Fung, Albert Y.C.; Zaider, Marco; Brooks, J. Paul

2002-01-01

In current practice, the planning volume for adjuvant brachytherapy treatment for soft-tissue sarcoma is either not determined a priori (in this case, seed locations are selected based on isodose curves conforming to a visual estimate of the planning volume), or it is derived via a tedious manual process. In either case, the process is subjective and time consuming, and is highly dependent on the human planner. The focus of the work described herein involves the development of an automated contouring algorithm to outline the planning volume. Such an automatic procedure will save time and provide a consistent and objective method for determining planning volumes. In addition, a definitive representation of the planning volume will allow for sophisticated brachytherapy treatment planning approaches to be applied when designing treatment plans, so as to maximize local tumour control and minimize normal tissue complications. An automated tumour volume contouring algorithm is developed utilizing computational geometry and numerical interpolation techniques in conjunction with an artificial intelligence method. The target volume is defined to be the slab of tissue r cm perpendicularly away from the curvilinear plane defined by the mesh of catheters. We assume that if adjacent catheters are over 2r cm apart, the tissue between the two catheters is part of the tumour bed. Input data consist of the digitized coordinates of the catheter positions in each of several cross-sectional slices of the tumour bed, and the estimated distance r from the catheters to the tumour surface. Mathematically, one can view the planning volume as the volume enclosed within a minimal smoothly-connected surface which contains a set of circles, each circle centred at a given catheter position in a given cross-sectional slice. The algorithm performs local interpolation on consecutive triplets of circles. The effectiveness of the algorithm is evaluated based on its performance on a collection of

Automated planning volume definition in soft-tissue sarcoma adjuvant brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Lee, Eva K. [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA (United States); School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, GA (United States); Fung, Albert Y.C.; Zaider, Marco [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY (United States); Brooks, J. Paul [School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, GA (United States)

2002-06-07

In current practice, the planning volume for adjuvant brachytherapy treatment for soft-tissue sarcoma is either not determined a priori (in this case, seed locations are selected based on isodose curves conforming to a visual estimate of the planning volume), or it is derived via a tedious manual process. In either case, the process is subjective and time consuming, and is highly dependent on the human planner. The focus of the work described herein involves the development of an automated contouring algorithm to outline the planning volume. Such an automatic procedure will save time and provide a consistent and objective method for determining planning volumes. In addition, a definitive representation of the planning volume will allow for sophisticated brachytherapy treatment planning approaches to be applied when designing treatment plans, so as to maximize local tumour control and minimize normal tissue complications. An automated tumour volume contouring algorithm is developed utilizing computational geometry and numerical interpolation techniques in conjunction with an artificial intelligence method. The target volume is defined to be the slab of tissue r cm perpendicularly away from the curvilinear plane defined by the mesh of catheters. We assume that if adjacent catheters are over 2r cm apart, the tissue between the two catheters is part of the tumour bed. Input data consist of the digitized coordinates of the catheter positions in each of several cross-sectional slices of the tumour bed, and the estimated distance r from the catheters to the tumour surface. Mathematically, one can view the planning volume as the volume enclosed within a minimal smoothly-connected surface which contains a set of circles, each circle centred at a given catheter position in a given cross-sectional slice. The algorithm performs local interpolation on consecutive triplets of circles. The effectiveness of the algorithm is evaluated based on its performance on a collection of

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

Robustness of IPSA optimized high-dose-rate prostate brachytherapy treatment plans to catheter displacements.

Science.gov (United States)

Poder, Joel; Whitaker, May

2016-06-01

Inverse planning simulated annealing (IPSA) optimized brachytherapy treatment plans are characterized with large isolated dwell times at the first or last dwell position of each catheter. The potential of catheter shifts relative to the target and organs at risk in these plans may lead to a more significant change in delivered dose to the volumes of interest relative to plans with more uniform dwell times. This study aims to determine if the Nucletron Oncentra dwell time deviation constraint (DTDC) parameter can be optimized to improve the robustness of high-dose-rate (HDR) prostate brachytherapy plans to catheter displacements. A set of 10 clinically acceptable prostate plans were re-optimized with a DTDC parameter of 0 and 0.4. For each plan, catheter displacements of 3, 7, and 14 mm were retrospectively applied and the change in dose volume histogram (DVH) indices and conformity indices analyzed. The robustness of clinically acceptable prostate plans to catheter displacements in the caudal direction was found to be dependent on the DTDC parameter. A DTDC value of 0 improves the robustness of planning target volume (PTV) coverage to catheter displacements, whereas a DTDC value of 0.4 improves the robustness of the plans to changes in hotspots. The results indicate that if used in conjunction with a pre-treatment catheter displacement correction protocol and a tolerance of 3 mm, a DTDC value of 0.4 may produce clinically superior plans. However, the effect of the DTDC parameter in plan robustness was not observed to be as strong as initially suspected.

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

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

Standardization of prostate brachytherapy treatment plans

International Nuclear Information System (INIS)

Ove, Roger; Wallner, Kent; Badiozamani, Kas; Korjsseon, Tammy; Sutlief, Steven

2001-01-01

Purpose: Whereas custom-designed plans are the norm for prostate brachytherapy, the relationship between linear prostate dimensions and volume calls into question the routine need for customized treatment planning. With the goal of streamlining the treatment-planning process, we have compared the treatment margins (TMs) achieved with one standard plan applied to patients with a wide range of prostate volumes. Methods and Materials: Preimplant transrectal ultrasound (TRUS) images of 50 unselected University of Washington patients with T1-T2 cancer and a prostate volume between 20 cc and 50 cc were studied. Patients were arbitrarily grouped into categories of 20-30 cc, 30-40 cc, and 40-50 cc. A standard 19-needle plan was devised for patients in the 30- to 40-cc range, using an arbitrary minimum margin of 5 mm around the gross tumor volume (GTV), making use of inverse planning technology to achieve 100% coverage of the target volume with accentuation of dose at the periphery and sparing of the central region. The idealized plan was applied to each patient's TRUS study. The distances (TMs) between the prostatic edge (GTV) and treated volume (TV) were determined perpendicular to the prostatic margin. Results: Averaged over the entire patient group, the ratio of thickness to width was 1.4, whereas the ratio of length to width was 1.3. These values were fairly constant over the range of volumes, emphasizing that the prostate retains its general shape as volume increases. The idealized standard plan was overlaid on the ultrasound images of the 17 patients in the 30- to 40-cc group and the V100, the percentage of target volume receiving 100% or more of the prescription dose, was 98% or greater for 15 of the 17 patients. The lateral and posterior TMs fell within a narrow range, most being within 2 mm of the idealized 5-mm TM. To estimate whether a 10-cc volume-interval stratification was reasonable, the standard plan generated from the 30- to 40-cc prostate model was

Verification and optimization of HDR surface mould brachytherapy plans using GAFCHROMIC EBT2 film: the ideal geometric case

International Nuclear Information System (INIS)

Sobolewski, Matthew; Haque, Mamoon

2011-01-01

Full text: Surface mould brachytherapy is used to treat superficial cancers due to conformal dose distributions and rapid dose fall-off with depth. In this work, we determine the effect of varying catheter number and prescription distance on dose distributions for surface mould plans using radiochromic film. Eight surface mould plans were generated using PLATO BPS (Version 14.3.2). Measurements were taken with Gafchromic EBT2 film over depths of 5-30 mm with an Ir-192 HDR source. Films were scanned using an Epson Expression 10000 XL flatbed scanner and analysed using RIT 113 software. The EBT2 films showed good agreement with an average difference of 2.8% compared to the planning system. The dose gradient in the interval ranging ±5 mm from the prescription point showed an 80% increase from the plan with maximum catheters (II) to the minimum (3). The size and extent of local dose maxima increased when fewer catheters were used. Increasing prescription distance decreased the dose gradient with a 20% reduction in dose occurring 4 mm superficially to the prescription point when prescription distance increased from 5 to 20 mm. Gafchromic EBT2 was used successfully to evaluate surface mould brachytherapy plans and is a useful tool for dose verification checks. High dose regions ne,u' to the catheter plane can be reduced by using a larger number of catheters and the prescription distance should be adjusted as a function of treatment depth varied by mould thickness.

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

CT-image based conformal high-dose rate brachytherapy boost in the conservative treatment of stage I - II breast cancer - introducing the procedure

International Nuclear Information System (INIS)

Kubaszewska, M.; Skowronek, J.; Chichel, A.; Kanikowski, M.; Dymnicka, M.

2008-01-01

Aim: Breast-conserving surgery (BCS) followed by radiotherapy (RT) has become the standard treatment for the majority of patients with early breast cancer. With regard to boost technique some disagreements are found between groups that are emphasizing the value of electron boost treatment and groups pointing out the value of interstitial brachytherapy (BT) boost treatment. We present the preliminary results in treating selected patients with early-stage breast cancer using high-dose-rate brachytherapy (HD R-BT) as a boost after breast conservation therapy (BCT). Materials/Methods: Between January 2006 and August 2007, a total of 58 female patients with first and second stage breast cancer underwent BCT. This therapeutic procedure involves BCS, whole breast radiation therapy (WBRT) and additional irradiation to the tumour bed (boost) using interstitial HDR-BT via flexible implant tubes. A 10 Gy boost dose was received by all patients. The treatment planning was based on CT-guided 3D (three-dimensional) reconstruction of the surgical clips, implant tubes and critical structures localization (skin and ribs). The accuracy of tumour bed localization, the conformity of planning target volume and treated volume were analyzed. Results: The evaluations of implant parameters involved the use of: dose volume histogram (DVH), the volume encompassed by the 100% reference isodose surface (V100%), the high dose volumecalculation (V150%, V200%, V300%), the dose non-uniformity ratio (DNR), and the conformity index (COIN). Our results were as follows: the mean PTV volume, the mean high dose volume (V150%; V200%; V300%), the DNR and COIN mean value were estimated at 57.38, 42.98, 21.38, 7.90, 0.52 and 0.83 respectively. Conclusions: CT-guided 3D HDR-BT is most appropriate for planning the boost procedure after BT especially in large breast volume, in cases with a deep seated tumour bed, as well as in patients with high risk for local recurrences. This technique reduces the

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

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.

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

Ultrasound-guided high dose rate conformal brachytherapy boost in prostate cancer: treatment description and preliminary results of a phase I/II clinical trial

Energy Technology Data Exchange (ETDEWEB)

Stromberg, Jannifer; Martinez, Alvaro; Gonzalez, Jose; Edmundson, Gregory; Ohanian, Neshan; Vicini, Frank; Hollander, Jay; Gustafson, Gary; Spencer, William; Di, Yan; Brabbins, Donald

1995-08-30

Purpose: To improve results for locally advanced prostate cancer, a prospective clinical trial of concurrent external beam irradiation and fractionated iridium-192 (Ir-192) high dose rate (HDR) conformal boost brachytherapy was initiated. Methods and Materials: Between November 1991 and February 1994, 99 implants were performed on 33 patients with prostatic adenocarcinoma at William Beaumont Hospital. Using AJCC staging criteria, 9 patients had T2b tumors, 17 patients had T2c tumors, and 7 patients had T3 disease. Patients were treated with (a) 45.6 Gy whole pelvis external irradiation and (b) three HDR fractions of 5.5 Gy each (18 patients) or 6 Gy each (15 patients) to the prostate. Transperineal needle implants using real-time ultrasound guidance with interactive on-line isodose distributions were performed on an outpatient basis during weeks 1, 2, and 3 of external irradiation. Acute toxicity was scored using the Radiation Therapy Oncology Group (RTOG) morbidity grading system. Results: This technique of concurrent external pelvic irradiation and conformal HDR brachytherapy was well tolerated. No significant intraoperative or perioperative complications occurred. Three patients (9%) experienced Grade 3 acute toxicity (two dysuria and one diarrhea). All toxicities were otherwise Grades 1 or 2 and were primarily as expected from pelvic external irradiation. Persistent implant-related toxicities included Grades 1-2 perineal pain (12%) and hematospermia (15%). Median follow-up time was 13 months. Serum prostatic-specific antigen (PSA) levels normalized in 91% of patients (29 out of 32) within 1-14 months (median 2.8 months) after irradiation. PSA levels were progressively decreasing in the other three patients at last measurement. Prospectively planned prostatic rebiopsies done at 18 months in the first 10 patients were negative in 9 out of 10 (90%). Conclusions: Acute toxicity has been acceptable with this unique approach using conformal high dose rate Ir-192

Inverse treatment planning based on MRI for HDR prostate brachytherapy

International Nuclear Information System (INIS)

Citrin, Deborah; Ning, Holly; Guion, Peter; Li Guang; Susil, Robert C.; Miller, Robert W.; Lessard, Etienne; Pouliot, Jean; Xie Huchen; Capala, Jacek; Coleman, C. Norman; Camphausen, Kevin; Menard, Cynthia

2005-01-01

Purpose: To develop and optimize a technique for inverse treatment planning based solely on magnetic resonance imaging (MRI) during high-dose-rate brachytherapy for prostate cancer. Methods and materials: Phantom studies were performed to verify the spatial integrity of treatment planning based on MRI. Data were evaluated from 10 patients with clinically localized prostate cancer who had undergone two high-dose-rate prostate brachytherapy boosts under MRI guidance before and after pelvic radiotherapy. Treatment planning MRI scans were systematically evaluated to derive a class solution for inverse planning constraints that would reproducibly result in acceptable target and normal tissue dosimetry. Results: We verified the spatial integrity of MRI for treatment planning. MRI anatomic evaluation revealed no significant displacement of the prostate in the left lateral decubitus position, a mean distance of 14.47 mm from the prostatic apex to the penile bulb, and clear demarcation of the neurovascular bundles on postcontrast imaging. Derivation of a class solution for inverse planning constraints resulted in a mean target volume receiving 100% of the prescribed dose of 95.69%, while maintaining a rectal volume receiving 75% of the prescribed dose of <5% (mean 1.36%) and urethral volume receiving 125% of the prescribed dose of <2% (mean 0.54%). Conclusion: Systematic evaluation of image spatial integrity, delineation uncertainty, and inverse planning constraints in our procedure reduced uncertainty in planning and treatment

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

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

IPIP: A new approach to inverse planning for HDR brachytherapy by directly optimizing dosimetric indices

International Nuclear Information System (INIS)

Siauw, Timmy; Cunha, Adam; Atamtuerk, Alper; Hsu, I-Chow; Pouliot, Jean; Goldberg, Ken

2011-01-01

Purpose: Many planning methods for high dose rate (HDR) brachytherapy require an iterative approach. A set of computational parameters are hypothesized that will give a dose plan that meets dosimetric criteria. A dose plan is computed using these parameters, and if any dosimetric criteria are not met, the process is iterated until a suitable dose plan is found. In this way, the dose distribution is controlled by abstract parameters. The purpose of this study is to develop a new approach for HDR brachytherapy by directly optimizing the dose distribution based on dosimetric criteria. Methods: The authors developed inverse planning by integer program (IPIP), an optimization model for computing HDR brachytherapy dose plans and a fast heuristic for it. They used their heuristic to compute dose plans for 20 anonymized prostate cancer image data sets from patients previously treated at their clinic database. Dosimetry was evaluated and compared to dosimetric criteria. Results: Dose plans computed from IPIP satisfied all given dosimetric criteria for the target and healthy tissue after a single iteration. The average target coverage was 95%. The average computation time for IPIP was 30.1 s on an Intel(R) Core TM 2 Duo CPU 1.67 GHz processor with 3 Gib RAM. Conclusions: IPIP is an HDR brachytherapy planning system that directly incorporates dosimetric criteria. The authors have demonstrated that IPIP has clinically acceptable performance for the prostate cases and dosimetric criteria used in this study, in both dosimetry and runtime. Further study is required to determine if IPIP performs well for a more general group of patients and dosimetric criteria, including other cancer sites such as GYN.

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...

Intraoperative real-time planned conformal prostate brachytherapy: Post-implantation dosimetric outcome and clinical implications

International Nuclear Information System (INIS)

Zelefsky, Michael J.; Yamada, Yoshiya; Cohen, Gil'ad N.; Sharma, Neha; Shippy, Alison M.; Fridman, David; Zaider, Marco

2007-01-01

Purpose: To report the dosimetric outcome of patients with clinically localized prostate cancer treated with I-125 permanent implantation using an intraoperative real-time conformal planning technique. Methods and materials: Five hundred and sixty-two patients with prostate cancer were treated with I-125 permanent interstitial implantation using a transrectal ultrasound-guided approach. Real-time intraoperative treatment planning software that incorporates inverse planning optimization was used. Dose-volume constraints for this inverse-planning system included: prostate V100 ≥95%, maximal urethral dose ≤120%, and average rectal dose 3 of the rectum was exposed to the prescription dose, the incidence of late grade 2 toxicity rectal toxicity was 9% compared to 4% for smaller volumes of the rectum exposed to similar doses (p = 0.003). No dosimetric parameter in these patients with tight dose confines for the urethra influenced acute or late urinary toxicity. Conclusion: Real-time intraoperative planning was associated with a 90% consistency of achieving the planned intraoperative dose constraints for target coverage and maintaining planned urethral and rectal constraints in a high percentage of implants. Rectal volumes of ≥2.5 cm 3 exposed to the prescription doses were associated with an increased incidence of grade 2 rectal bleeding. Further enhancements in imaging guidance for optimal seed deposition are needed to guarantee optimal dose distribution for all patients. Whether such improvements lead to further reduction in acute and late morbidities associated with therapy requires further study

Sci-Thur PM – Brachytherapy 06: 3D Printed Surface Applicators for High Dose Rate Brachytherapy

International Nuclear Information System (INIS)

Clarke, Scott; Yewondwossen, Mammo; Robar, James

2016-01-01

Purpose: The purpose of this work is to develop a new applicator for administering high dose rate (HDR) brachytherapy using 3D printing technology. Primary advantages of using a 3D printed applicator will be to offer a more streamlined approach for therapists and patients while achieving better conformity, reproducibility, and patient specific applicators. Methods: A phantom study was conducted to measure the effectiveness of a 3D printed surface applicator by analyzing tumours on three locations of the body: the foot, nose, and scalp. The applicator was designed using Eclipse and further modified using Blender to create the catheter tunnels before being printed on a Lulzbot Taz 5 3D printer. A radiation plan was made using Oncentra Brachytherapy for a control treatment option using Freiburg Flaps and one with the novel method of a 3D printed applicator. A comparative analysis was made using D90, D100, V100, V150, and V200 Results: The 3D printed applicator showed comparable dose coverage with significant improvements on highly irregular surfaces when analyzed against a plan made using Freiburg Flaps. Although both plans exhibited complete tumour coverage, the 3D applicator showed improvements in D90 and V150 and the 3D applicator had a dose homogeneity index (DHI) of 0.99 compared to a DHI of 0.97 for the control. Therapist prep time also dropped significantly due to the lack of need for a thermoplastic mesh. Conclusions: 3D printed applicators for treatment of superficial sites proved to offer more patient convenience, less prep time, better conformity and tighter margins.

Sci-Thur PM – Brachytherapy 06: 3D Printed Surface Applicators for High Dose Rate Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Clarke, Scott; Yewondwossen, Mammo; Robar, James [Dalhousie University, Nova Scotia Cancer Centre, Capital District Health Authority (Canada)

2016-08-15

Purpose: The purpose of this work is to develop a new applicator for administering high dose rate (HDR) brachytherapy using 3D printing technology. Primary advantages of using a 3D printed applicator will be to offer a more streamlined approach for therapists and patients while achieving better conformity, reproducibility, and patient specific applicators. Methods: A phantom study was conducted to measure the effectiveness of a 3D printed surface applicator by analyzing tumours on three locations of the body: the foot, nose, and scalp. The applicator was designed using Eclipse and further modified using Blender to create the catheter tunnels before being printed on a Lulzbot Taz 5 3D printer. A radiation plan was made using Oncentra Brachytherapy for a control treatment option using Freiburg Flaps and one with the novel method of a 3D printed applicator. A comparative analysis was made using D90, D100, V100, V150, and V200 Results: The 3D printed applicator showed comparable dose coverage with significant improvements on highly irregular surfaces when analyzed against a plan made using Freiburg Flaps. Although both plans exhibited complete tumour coverage, the 3D applicator showed improvements in D90 and V150 and the 3D applicator had a dose homogeneity index (DHI) of 0.99 compared to a DHI of 0.97 for the control. Therapist prep time also dropped significantly due to the lack of need for a thermoplastic mesh. Conclusions: 3D printed applicators for treatment of superficial sites proved to offer more patient convenience, less prep time, better conformity and tighter margins.

Towards real-time 3D ultrasound planning and personalized 3D printing for breast HDR brachytherapy treatment

International Nuclear Information System (INIS)

Poulin, Eric; Gardi, Lori; Fenster, Aaron; Pouliot, Jean; Beaulieu, Luc

2015-01-01

Two different end-to-end procedures were tested for real-time planning in breast HDR brachytherapy treatment. Both methods are using a 3D ultrasound (3DUS) system and a freehand catheter optimization algorithm. They were found fast and efficient. We demonstrated a proof-of-concept approach for personalized real-time guidance and planning to breast HDR brachytherapy treatments

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.

Intensity Modulated Proton Beam Radiation for Brachytherapy in Patients With Cervical Carcinoma

Energy Technology Data Exchange (ETDEWEB)

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

Preparation of a program for the independent verification of the brachytherapy planning systems calculations

International Nuclear Information System (INIS)

V Carmona, V.; Perez-Calatayud, J.; Lliso, F.; Richart Sancho, J.; Ballester, F.; Pujades-Claumarchirant, M.C.; Munoz, M.

2010-01-01

In this work a program is presented that independently checks for each patient the treatment planning system calculations in low dose rate, high dose rate and pulsed dose rate brachytherapy. The treatment planning system output text files are automatically loaded in this program in order to get the source coordinates, the desired calculation point coordinates and the dwell times when it is the case. The source strength and the reference dates are introduced by the user. The program allows implementing the recommendations about independent verification of the clinical brachytherapy dosimetry in a simple and accurate way, in few minutes. (Author).

Dosimetric comparison of vaginal vault ovoid brachytherapy versus intensity-modulated radiation therapy plans in postoperative patients of cervical carcinoma following whole pelvic radiotherapy

Directory of Open Access Journals (Sweden)

Divya Khosla

2014-01-01

Full Text Available Introduction: Dosimetric study to compare high dose rate (HDR vaginal vault ovoid brachytherapy plan versus intensity-modulated radiation therapy (IMRT boost plan for doses delivered to target volume and organs at risk (OAR in postoperative patients of cervical carcinoma following whole pelvic radiotherapy (WPRT. Materials and Methods: Fifteen postoperative patients of cervical carcinoma suitable for vaginal ovoid brachytherapy following WPRT of 46 Gy/23 fractions/4.5 weeks were included. All were treated with brachytherapy (two sessions of 8.5 Gy each. The equivalent dose for IMRT was calculated by computing biologically effective dose of brachytherapy by linear quadratic model. Dose of brachytherapy (two sessions of 8.5 Gy was equivalent to IMRT dose of 26 Gy/13 fractions. Doses to target volume and OAR were compared between HDR and IMRT plans. Results: Target volume was well covered with both HDR and IMRT plans, but dose with brachytherapy was much higher (P < 0.05. Mean doses, doses to 0.1, 1, 2, and 5cc, 1/3 rd , 1/2, and 2/3 rd volume of bladder and rectum were significantly lower with HDR plans. Conclusion: In postoperative patients of cervical carcinoma, HDR brachytherapy following WPRT appears to be better than IMRT for tumor coverage and reducing dose to critical organs.

Impact of using linear optimization models in dose planning for HDR brachytherapy

International Nuclear Information System (INIS)

Holm, Aasa; Larsson, Torbjoern; Carlsson Tedgren, Aasa

2012-01-01

Purpose: Dose plans generated with optimization models hitherto used in high-dose-rate (HDR) brachytherapy have shown a tendency to yield longer dwell times than manually optimized plans. Concern has been raised for the corresponding undesired hot spots, and various methods to mitigate these have been developed. The hypotheses upon this work is based are (a) that one cause for the long dwell times is the use of objective functions comprising simple linear penalties and (b) that alternative penalties, as these are piecewise linear, would lead to reduced length of individual dwell times. Methods: The characteristics of the linear penalties and the piecewise linear penalties are analyzed mathematically. Experimental comparisons between the two types of penalties are carried out retrospectively for a set of prostate cancer patients. Results: When the two types of penalties are compared, significant changes can be seen in the dwell times, while most dose-volume parameters do not differ significantly. On average, total dwell times were reduced by 4.2%, with a reduction of maximum dwell times by 25%, when the alternative penalties were used. Conclusions: The use of linear penalties in optimization models for HDR brachytherapy is one cause for the undesired long dwell times that arise in mathematically optimized plans. By introducing alternative penalties, a significant reduction in dwell times can be achieved for HDR brachytherapy dose plans. Although various measures for mitigating the long dwell times are already available, the observation that linear penalties contribute to their appearance is of fundamental interest.

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.

A new optimization method using a compressed sensing inspired solver for real-time LDR-brachytherapy treatment planning

International Nuclear Information System (INIS)

Guthier, C; Aschenbrenner, K P; Buergy, D; Ehmann, M; Wenz, F; Hesser, J W

2015-01-01

This work discusses a novel strategy for inverse planning in low dose rate brachytherapy. It applies the idea of compressed sensing to the problem of inverse treatment planning and a new solver for this formulation is developed. An inverse planning algorithm was developed incorporating brachytherapy dose calculation methods as recommended by AAPM TG-43. For optimization of the functional a new variant of a matching pursuit type solver is presented. The results are compared with current state-of-the-art inverse treatment planning algorithms by means of real prostate cancer patient data. The novel strategy outperforms the best state-of-the-art methods in speed, while achieving comparable quality. It is able to find solutions with comparable values for the objective function and it achieves these results within a few microseconds, being up to 542 times faster than competing state-of-the-art strategies, allowing real-time treatment planning. The sparse solution of inverse brachytherapy planning achieved with methods from compressed sensing is a new paradigm for optimization in medical physics. Through the sparsity of required needles and seeds identified by this method, the cost of intervention may be reduced. (paper)

A new optimization method using a compressed sensing inspired solver for real-time LDR-brachytherapy treatment planning

Science.gov (United States)

Guthier, C.; Aschenbrenner, K. P.; Buergy, D.; Ehmann, M.; Wenz, F.; Hesser, J. W.

2015-03-01

This work discusses a novel strategy for inverse planning in low dose rate brachytherapy. It applies the idea of compressed sensing to the problem of inverse treatment planning and a new solver for this formulation is developed. An inverse planning algorithm was developed incorporating brachytherapy dose calculation methods as recommended by AAPM TG-43. For optimization of the functional a new variant of a matching pursuit type solver is presented. The results are compared with current state-of-the-art inverse treatment planning algorithms by means of real prostate cancer patient data. The novel strategy outperforms the best state-of-the-art methods in speed, while achieving comparable quality. It is able to find solutions with comparable values for the objective function and it achieves these results within a few microseconds, being up to 542 times faster than competing state-of-the-art strategies, allowing real-time treatment planning. The sparse solution of inverse brachytherapy planning achieved with methods from compressed sensing is a new paradigm for optimization in medical physics. Through the sparsity of required needles and seeds identified by this method, the cost of intervention may be reduced.

BrachyTPS -Interactive point kernel code package for brachytherapy treatment planning of gynaecological cancers

International Nuclear Information System (INIS)

Thilagam, L.; Subbaiah, K.V.

2008-01-01

Brachytherapy treatment planning systems (TPS) are always recommended to account for the effect of tissue, applicator and shielding material heterogeneities exist in Intracavitary brachytherapy (ICBT) applicators. Most of the commercially available brachytherapy TPS softwares estimate the absorbed dose at a point, only taking care of the contributions of individual sources and the source distribution, neglecting the dose perturbations arising from the applicator design and construction. So the doses estimated by them are not much accurate under realistic clinical conditions. In this regard, interactive point kernel rode (BrachyTPS) has been developed to perform independent dose calculations by taking into account the effect of these heterogeneities, using two regions build up factors, proposed by Kalos. As primary input data, the code takes patients' planning data including the source specifications, dwell positions, dwell times and it computes the doses at reference points by dose point kernel formalisms, with multi-layer shield build-up factors accounting for the contributions from scattered radiation. In addition to performing dose distribution calculations, this code package is capable of displaying an isodose distribution curve into the patient anatomy images. The primary aim of this study is to validate the developed point kernel code integrated with treatment planning systems against the other tools which are available in the market. In the present work, three brachytherapy applicators commonly used in the treatment of uterine cervical carcinoma, Board of Radiation Isotope and Technology (BRIT) made low dose rate (LDR) applicator, Fletcher Green type LDR applicator and Fletcher Williamson high dose rate (HDR) applicator were studied to test the accuracy of the software

A Dosimetric Comparison of Accelerated Partial Breast Irradiation Techniques: Multicatheter Interstitial Brachytherapy, Three-Dimensional Conformal Radiotherapy, and Supine Versus Prone Helical Tomotherapy

International Nuclear Information System (INIS)

Patel, Rakesh R.; Becker, Stewart J.; Das, Rupak K.; Mackie, Thomas R.

2007-01-01

Purpose: To compare dosimetrically four different techniques of accelerated partial breast irradiation (APBI) in the same patient. Methods and Materials: Thirteen post-lumpectomy interstitial brachytherapy (IB) patients underwent imaging with preimplant computed tomography (CT) in the prone and supine position. These CT scans were then used to generate three-dimensional conformal radiotherapy (3D-CRT) and prone and supine helical tomotherapy (PT and ST, respectively) APBI plans and compared with the treated IB plans. Dose-volume histogram analysis and the mean dose (NTD mean ) values were compared. Results: Planning target volume coverage was excellent for all methods. Statistical significance was considered to be a p value mean dose of 1.3 Gy 3 and 1.2 Gy 3 , respectively. Both of these methods were statistically significantly lower than the supine external beam techniques. Overall, all four methods yielded similar low doses to the heart. Conclusions: The use of IB and PT resulted in greater normal tissue sparing (especially ipsilateral breast and lung) than the use of supine external beam techniques of 3D-CRT or ST. However, the choice of APBI technique must be tailored to the patient's anatomy, lumpectomy cavity location, and overall treatment goals

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

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.

Dosimetric comparison of intensity-modulated, conformal, and four-field pelvic radiotherapy boost plans for gynecologic cancer: a retrospective planning study

International Nuclear Information System (INIS)

Chan, Philip; Yeo, Inhwan; Perkins, Gregory; Fyles, Anthony; Milosevic, Michael

2006-01-01

To evaluate intensity-modulated radiation therapy (IMRT) as an alternative to conformal radiotherapy (CRT) or 4-field box boost (4FB) in women with gynecologic malignancies who are unsuitable for brachytherapy for technical or medical reasons. Dosimetric and toxicity information was analyzed for 12 patients with cervical (8), endometrial (2) or vaginal (2) cancer previously treated with external beam pelvic radiotherapy and a CRT boost. Optimized IMRT boost treatment plans were then developed for each of the 12 patients and compared to CRT and 4FB plans. The plans were compared in terms of dose conformality and critical normal tissue avoidance. The median planning target volume (PTV) was 151 cm 3 (range 58–512 cm 3 ). The median overlap of the contoured rectum with the PTV was 15 (1–56) %, and 11 (4–35) % for the bladder. Two of the 12 patients, both with large PTVs and large overlap of the contoured rectum and PTV, developed grade 3 rectal bleeding. The dose conformity was significantly improved with IMRT over CRT and 4FB (p ≤ 0.001 for both). IMRT also yielded an overall improvement in the rectal and bladder dose-volume distributions relative to CRT and 4FB. The volume of rectum that received the highest doses (>66% of the prescription) was reduced by 22% (p < 0.001) with IMRT relative to 4FB, and the bladder volume was reduced by 19% (p < 0.001). This was at the expense of an increase in the volume of these organs receiving doses in the lowest range (<33%). These results indicate that IMRT can improve target coverage and reduce dose to critical structures in gynecologic patients receiving an external beam radiotherapy boost. This dosimetric advantage will be integrated with other patient and treatment-specific factors, particularly internal tumor movement during fractionated radiotherapy, in the context of a future image-guided radiation therapy study

Suitability of point kernel dose calculation techniques in brachytherapy treatment planning

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Lakshminarayanan Thilagam

2010-01-01

Full Text Available Brachytherapy treatment planning system (TPS is necessary to estimate the dose to target volume and organ at risk (OAR. TPS is always recommended to account for the effect of tissue, applicator and shielding material heterogeneities exist in applicators. However, most brachytherapy TPS software packages estimate the absorbed dose at a point, taking care of only the contributions of individual sources and the source distribution, neglecting the dose perturbations arising from the applicator design and construction. There are some degrees of uncertainties in dose rate estimations under realistic clinical conditions. In this regard, an attempt is made to explore the suitability of point kernels for brachytherapy dose rate calculations and develop new interactive brachytherapy package, named as BrachyTPS, to suit the clinical conditions. BrachyTPS is an interactive point kernel code package developed to perform independent dose rate calculations by taking into account the effect of these heterogeneities, using two regions build up factors, proposed by Kalos. The primary aim of this study is to validate the developed point kernel code package integrated with treatment planning computational systems against the Monte Carlo (MC results. In the present work, three brachytherapy applicators commonly used in the treatment of uterine cervical carcinoma, namely (i Board of Radiation Isotope and Technology (BRIT low dose rate (LDR applicator and (ii Fletcher Green type LDR applicator (iii Fletcher Williamson high dose rate (HDR applicator, are studied to test the accuracy of the software. Dose rates computed using the developed code are compared with the relevant results of the MC simulations. Further, attempts are also made to study the dose rate distribution around the commercially available shielded vaginal applicator set (Nucletron. The percentage deviations of BrachyTPS computed dose rate values from the MC results are observed to be within plus/minus 5

Assessment of dose homogeneity in conformal interstitial breast brachytherapy with special respect to ICRU recommendations

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Tibor Major

2011-09-01

Full Text Available Purpose: To present the results of dose homogeneity analysis for breast cancer patients treated with image-basedconformal interstitial brachytherapy, and to investigate the usefulness of the ICRU recommendations. Material and methods: Treatment plans of forty-nine patients who underwent partial breast irradiation with interstitialbrachytherapy were analyzed. Quantitative parameters were used to characterize dose homogeneity. Dose nonuniformityratio (DNR, dose homogeneity index (DHI, uniformity index (UI and quality index (QI were calculated.Furthermore, parameters recommended by the ICRU 58 such as minimum target dose (MTD, mean central dose (MCD,high dose volume, low dose volume and the spread between local minimum doses were determined. Correlationsbetween the calculated homogeneity parameters and usefulness of the ICRU parameters in image-based brachytherapywere investigated. Results: Catheters with mean number of 15 (range: 6-25 were implanted in median 4 (range: 3-6 planes. The volu -me of the PTV ranged from 15.5 cm3 to 176 cm3. The mean DNR was 0.32, the DHI 0.66, the UI 1.49 and the QI 1.94. Relatedto the prescribed dose, the MTD was 69% and the MCD 135%. The mean high dose volume was 8.1 cm3 (10%, whilethe low dose volume was 63.8 cm3 (96%. The spread between minimum doses in central plane ranged from –14% to+20%. Good correlation was found between the DNR and the DHI (R2 = 0.7874, and the DNR correlated well with theUI (R2 = 0.7615 also. No correlation was found between the ICRU parameters and any other volumetric parameters. Conclusions: To characterize the dose uniformity in high-dose rate breast implants, DVH-related homogeneityparameters representing the full 3D dose distributions are mandatory to be used. In many respects the current re commendationsof the ICRU Report 58 are already outdated, and it is well-timed to set up new recommendations, whichare more feasible for image-guided conformal interstitial brachytherapy.

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

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.

Verification of the plan dosimetry for high dose rate brachytherapy using metal-oxide-semiconductor field effect transistor detectors

International Nuclear Information System (INIS)

Qi Zhenyu; Deng Xiaowu; Huang Shaomin; Lu Jie; Lerch, Michael; Cutajar, Dean; Rosenfeld, Anatoly

2007-01-01

The feasibility of a recently designed metal-oxide-semiconductor field effect transistor (MOSFET) dosimetry system for dose verification of high dose rate (HDR) brachytherapy treatment planning was investigated. MOSFET detectors were calibrated with a 0.6 cm 3 NE-2571 Farmer-type ionization chamber in water. Key characteristics of the MOSFET detectors, such as the energy dependence, that will affect phantom measurements with HDR 192 Ir sources were measured. The MOSFET detector was then applied to verify the dosimetric accuracy of HDR brachytherapy treatments in a custom-made water phantom. Three MOSFET detectors were calibrated independently, with the calibration factors ranging from 0.187 to 0.215 cGy/mV. A distance dependent energy response was observed, significant within 2 cm from the source. The new MOSFET detector has a good reproducibility ( 2 =1). It was observed that the MOSFET detectors had a linear response to dose until the threshold voltage reached approximately 24 V for 192 Ir source measurements. Further comparison of phantom measurements using MOSFET detectors with dose calculations by a commercial treatment planning system for computed tomography-based brachytherapy treatment plans showed that the mean relative deviation was 2.2±0.2% for dose points 1 cm away from the source and 2.0±0.1% for dose points located 2 cm away. The percentage deviations between the measured doses and the planned doses were below 5% for all the measurements. The MOSFET detector, with its advantages of small physical size and ease of use, is a reliable tool for quality assurance of HDR brachytherapy. The phantom verification method described here is universal and can be applied to other HDR brachytherapy treatments

CT-Based Brachytherapy Treatment Planning using Monte Carlo Simulation Aided by an Interface Software

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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

Contributions of imaging to radiation therapy planning for uterine cervix carcinoma

International Nuclear Information System (INIS)

Thomas, L.

2000-01-01

External irradiation and brachytherapy are curative in the treatment of carcinoma of the cervix. The aim of radiotherapy is to optimize the irradiation of the target volume and to optimize the irradiation of the target volume and to reduce the dose to critical organs. The use of imaging (computed tomography and magnetic resonance imaging (computed tomography and magnetic resonance imaging added to clinical findings and standard guidelines) are studied in the treatment planning of external irradiation and brachytherapy in carcinoma of the cervix. Imaging allows an individualized and conformal treatment planning. (author)

Image Guided Cervical Brachytherapy: 2014 Survey of the American Brachytherapy Society

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Grover, Surbhi, E-mail: Surbhi.grover@uphs.upenn.edu [Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Harkenrider, Matthew M. [Department of Radiation Oncology, Stritch School of Medicine, Loyola University Chicago, Chicago, Illinois (United States); Cho, Linda P. [Department of Radiation Oncology, Brigham & Women' s Hospital/Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Erickson, Beth [Department Radiation Oncology, Froedtert Hospital and Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Small, Christina [Department of Public Health Sciences, Stritch School of Medicine, Loyola University Chicago, Chicago, Illinois (United States); Small, William [Department of Radiation Oncology, Stritch School of Medicine, Loyola University Chicago, Chicago, Illinois (United States); Viswanathan, Akila N. [Department of Radiation Oncology, Brigham & Women' s Hospital/Dana-Farber Cancer Institute, Boston, Massachusetts (United States)

2016-03-01

Purpose: To provide an update of the 2007 American brachytherapy survey on image-based brachytherapy, which showed that in the setting of treatment planning for gynecologic brachytherapy, although computed tomography (CT) was often used for treatment planning, most brachytherapists used point A for dose specification. Methods and Materials: A 45-question electronic survey on cervical cancer brachytherapy practice patterns was sent to all American Brachytherapy Society members and additional radiation oncologists and physicists based in the United States between January and September 2014. Responses from the 2007 survey and the present survey were compared using the χ{sup 2} test. Results: There were 370 respondents. Of those, only respondents, not in training, who treat more than 1 cervical cancer patient per year and practice in the United States, were included in the analysis (219). For dose specification to the target (cervix and tumor), 95% always use CT, and 34% always use MRI. However, 46% use point A only for dose specification to the target. There was a lot of variation in parameters used for dose evaluation of target volume and normal tissues. Compared with the 2007 survey, use of MRI has increased from 2% to 34% (P<.0001) for dose specification to the target. Use of volume-based dose delineation to the target has increased from 14% to 52% (P<.0001). Conclusion: Although use of image-based brachytherapy has increased in the United States since the 2007 survey, there is room for further growth, particularly with the use of MRI. This increase may be in part due to educational initiatives. However, there is still significant heterogeneity in brachytherapy practice in the United States, and future efforts should be geared toward standardizing treatment.

3-D conformal radiation therapy - Part I: Treatment planning

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Burman, Chandra M.; Mageras, Gikas S.

1997-01-01

Objective: In this presentation we will look into the basic components of 3-dimensional conformal treatment planning, and will discuss planning for some selected sites. We will also review some current and future trends in 3-D treatment planning. External beam radiation therapy is one of the arms of cancer treatment. In the recent years 3-D conformal therapy had significant impact on the practice of external beam radiation therapy. Conformal radiation therapy shapes the high-dose volume so as to conform to the target volume while minimizing the dose to the surrounding normal tissues. The advances that have been achieved in conformal therapy are in part due to the development of 3-D treatment planning, which in turn has capitalized on 3-D imaging for tumor and normal tissue localization, as well as on available computational power for the calculation of 3-D dose distributions, visualization of anatomical and dose volumes, and numerical evaluation of treatment plans. In this course we will give an overview of how 3-D conformal treatments are designed and transferred to the patient. Topics will include: 1) description of the major components of a 3-D treatment planning system, 2) techniques for designing treatments, 3) evaluation of treatment plans using dose distribution displays, dose-volume histograms and normal tissue complication probabilities, 4) implementation of treatments using shaped blocks and multileaf collimators, 5) verification of treatment delivery using portal films and electronic portal imaging devices. We will also discuss some current and future trends in 3-D treatment planning, such as field shaping with multileaf collimation, computerized treatment plan optimization, including the use of nonuniform beam profiles (intensity modulation), and incorporating treatment uncertainties due to patient positioning errors and organ motion into treatment planning process

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

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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.)

SU-F-T-65: AutomaticTreatment Planning for High-Dose Rate (HDR) Brachytherapy with a VaginalCylinder Applicator

International Nuclear Information System (INIS)

Zhou, Y; Tan, J; Jiang, S; Albuquerque, K; Jia, X

2016-01-01

Purpose: High dose rate (HDR) brachytherapy treatment planning is conventionally performed in a manual fashion. Yet it is highly desirable to perform computerized automated planning to improve treatment planning efficiency, eliminate human errors, and reduce plan quality variation. The goal of this research is to develop an automatic treatment planning tool for HDR brachytherapy with a cylinder applicator for vaginal cancer. Methods: After inserting the cylinder applicator into the patient, a CT scan was acquired and was loaded to an in-house developed treatment planning software. The cylinder applicator was automatically segmented using image-processing techniques. CTV was generated based on user-specified treatment depth and length. Locations of relevant points (apex point, prescription point, and vaginal surface point), central applicator channel coordinates, and dwell positions were determined according to their geometric relations with the applicator. Dwell time was computed through an inverse optimization process. The planning information was written into DICOM-RT plan and structure files to transfer the automatically generated plan to a commercial treatment planning system for plan verification and delivery. Results: We have tested the system retrospectively in nine patients treated with vaginal cylinder applicator. These cases were selected with different treatment prescriptions, lengths, depths, and cylinder diameters to represent a large patient population. Our system was able to generate treatment plans for these cases with clinically acceptable quality. Computation time varied from 3–6 min. Conclusion: We have developed a system to perform automated treatment planning for HDR brachytherapy with a cylinder applicator. Such a novel system has greatly improved treatment planning efficiency and reduced plan quality variation. It also served as a testbed to demonstrate the feasibility of automatic HDR treatment planning for more complicated cases.

SU-F-T-65: AutomaticTreatment Planning for High-Dose Rate (HDR) Brachytherapy with a VaginalCylinder Applicator

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Zhou, Y; Tan, J; Jiang, S; Albuquerque, K; Jia, X [UT Southwestern Medical Center, Dallas, TX (United States)

2016-06-15

Purpose: High dose rate (HDR) brachytherapy treatment planning is conventionally performed in a manual fashion. Yet it is highly desirable to perform computerized automated planning to improve treatment planning efficiency, eliminate human errors, and reduce plan quality variation. The goal of this research is to develop an automatic treatment planning tool for HDR brachytherapy with a cylinder applicator for vaginal cancer. Methods: After inserting the cylinder applicator into the patient, a CT scan was acquired and was loaded to an in-house developed treatment planning software. The cylinder applicator was automatically segmented using image-processing techniques. CTV was generated based on user-specified treatment depth and length. Locations of relevant points (apex point, prescription point, and vaginal surface point), central applicator channel coordinates, and dwell positions were determined according to their geometric relations with the applicator. Dwell time was computed through an inverse optimization process. The planning information was written into DICOM-RT plan and structure files to transfer the automatically generated plan to a commercial treatment planning system for plan verification and delivery. Results: We have tested the system retrospectively in nine patients treated with vaginal cylinder applicator. These cases were selected with different treatment prescriptions, lengths, depths, and cylinder diameters to represent a large patient population. Our system was able to generate treatment plans for these cases with clinically acceptable quality. Computation time varied from 3–6 min. Conclusion: We have developed a system to perform automated treatment planning for HDR brachytherapy with a cylinder applicator. Such a novel system has greatly improved treatment planning efficiency and reduced plan quality variation. It also served as a testbed to demonstrate the feasibility of automatic HDR treatment planning for more complicated cases.

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

The Adjoint Method for The Optimization of Brachytherapy and Radiotherapy Patient Treatment Planning Procedures Using Monte Carlo Calculations

International Nuclear Information System (INIS)

Henderson, D.L.; Yoo, S.; Kowalok, M.; Mackie, T.R.; Thomadsen, B.R.

2001-01-01

The goal of this project is to investigate the use of the adjoint method, commonly used in the reactor physics community, for the optimization of radiation therapy patient treatment plans. Two different types of radiation therapy are being examined, interstitial brachytherapy and radiotherapy. In brachytherapy radioactive sources are surgically implanted within the diseased organ such as the prostate to treat the cancerous tissue. With radiotherapy, the x-ray source is usually located at a distance of about 1-meter from the patient and focused on the treatment area. For brachytherapy the optimization phase of the treatment plan consists of determining the optimal placement of the radioactive sources, which delivers the prescribed dose to the disease tissue while simultaneously sparing (reducing) the dose to sensitive tissue and organs. For external beam radiation therapy the optimization phase of the treatment plan consists of determining the optimal direction and intensity of beam, which provides complete coverage of the tumor region with the prescribed dose while simultaneously avoiding sensitive tissue areas. For both therapy methods, the optimal treatment plan is one in which the diseased tissue has been treated with the prescribed dose and dose to the sensitive tissue and organs has been kept to a minimum

Computerized planning and dosimetry for brachytherapy in carcinomas cervix

International Nuclear Information System (INIS)

Kizilbash, N.A.; Jabeen, K.; Hussain, R.

1996-01-01

A project on the use of computerize planning and dosimetry for brachytherapy in carcinoma of cervix was started at NORI (Nuclear Medicine, Oncology and Radiotherapy Institute, Islamabad) in september 1990. A total number of 182 patients were included in the study over a period of three years. The treatment of all these patients was done by external radiation as well as the intracavitary therapy. Planning and dosimetry was done according to ICRU 38 recommendations. 70 patients were planned with two computers TP-II (Dr. J. Cunningham's software) and PC based system (Dr. Kallinger's software, BTI system). From the results of the two computers TP-II and PC, it can be seen that the difference in a absorbed dose for all recommended points in not going to harm the patient. The dose to the bladder and the rectum in our studies is quite low because of the low activity in the ovoid sources. (author)

SU-G-201-01: An Automated Treatment Plan Quality Assurance Program for High-Dose Rate (HDR) Brachytherapy with a VaginalCylinder Applicator

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Zhou, Y; Tan, J; Jiang, S; Albuquerque, K; Jia, X [UT Southwestern Medical Center, Dallas, TX (United States)

2016-06-15

Purpose: Plan specific quality assurance (QA) is an important step in high dose rate (HDR) brachytherapy to ensure the integrity of a treatment plan. The conventional approach is to assemble a set of plan screen-captures in a document and have an independent plan-checker to verify it. Not only is this approach cumbersome and time-consuming, using a document also limits the items that can be verified, hindering plan quality and patient safety. We have initiated efforts to develop a web-based HDR brachytherapy QA system called AutoBrachy QA, for comprehensive and efficient QA. This abstract reports a new plugin in this system for the QA of a cylinder HDR brachytherapy treatment. Methods: A cylinder plan QA module was developed using Python. It was plugged into our AutoBrachy QA system. This module extracted information from CT images and treatment plan. Image processing techniques were employed to obtain geometric parameters, e.g. cylinder diameter. A comprehensive set of eight geometrical and eight dosimetric features of the plan were validated against user specified planning parameter, such as prescription value, treatment depth and length, etc. A PDF document was generated, consisting of a summary QA sheet with all the QA results, as well as images showing plan details. Results: The cylinder QA program has been implemented in our clinic. To date, it has been used in 11 patient cases and was able to successfully perform QA tests in all of them. The QA program reduced the average plan QA time from 7 min using conventional manual approach to 0.5 min. Conclusion: Being a new module in our AutoBrachy QA system, an automated treatment plan QA module for cylinder HDR brachytherapy has been successfully developed and clinically implemented. This module improved clinical workflow and plan integrity compared to the conventional manual approach.

SU-G-201-01: An Automated Treatment Plan Quality Assurance Program for High-Dose Rate (HDR) Brachytherapy with a VaginalCylinder Applicator

International Nuclear Information System (INIS)

Zhou, Y; Tan, J; Jiang, S; Albuquerque, K; Jia, X

2016-01-01

Purpose: Plan specific quality assurance (QA) is an important step in high dose rate (HDR) brachytherapy to ensure the integrity of a treatment plan. The conventional approach is to assemble a set of plan screen-captures in a document and have an independent plan-checker to verify it. Not only is this approach cumbersome and time-consuming, using a document also limits the items that can be verified, hindering plan quality and patient safety. We have initiated efforts to develop a web-based HDR brachytherapy QA system called AutoBrachy QA, for comprehensive and efficient QA. This abstract reports a new plugin in this system for the QA of a cylinder HDR brachytherapy treatment. Methods: A cylinder plan QA module was developed using Python. It was plugged into our AutoBrachy QA system. This module extracted information from CT images and treatment plan. Image processing techniques were employed to obtain geometric parameters, e.g. cylinder diameter. A comprehensive set of eight geometrical and eight dosimetric features of the plan were validated against user specified planning parameter, such as prescription value, treatment depth and length, etc. A PDF document was generated, consisting of a summary QA sheet with all the QA results, as well as images showing plan details. Results: The cylinder QA program has been implemented in our clinic. To date, it has been used in 11 patient cases and was able to successfully perform QA tests in all of them. The QA program reduced the average plan QA time from 7 min using conventional manual approach to 0.5 min. Conclusion: Being a new module in our AutoBrachy QA system, an automated treatment plan QA module for cylinder HDR brachytherapy has been successfully developed and clinically implemented. This module improved clinical workflow and plan integrity compared to the conventional manual 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.

3-D conformal treatment of prostate cancer to 74 Gy vs. high-dose-rate brachytherapy boost: A cross-sectional quality-of-life survey

International Nuclear Information System (INIS)

Vordermark, Dirk

2006-01-01

The effects of two modalities of dose-escalated radiotherapy on health-related quality of life (HRQOL) were compared. Forty-one consecutive patients were treated with a 3-D conformal (3-DC) boost to 74 Gy, and 43 with high-dose rate (HDR) brachytherapy boost (2x9 Gy), following 3-D conformal treatment to 46 Gy. Median age was 70 years in both groups, median initial PSA was 7.9 μg/l in 3-DC boost patients and 8.1 μg/l in HDR boost patients. Stage was 7 in 52% and 47%, respectively. HRQOL was assessed cross-sectionally using EORTC QLQ-C30 and organ-specific PR25 modules 3-32 (median 19) and 4-25 (median 14) months after treatment, respectively. Questionnaires were completed by 93% and 97% of patients, respectively. Diarrhea and insomnia scores were significantly increased in both groups. In the PR25 module, scores of 3-DC boost and HDR boost patients for urinary, bowel and treatment-related symptoms were similar. Among responders, 34% of 3-DC boost patients and 86% of HDR boost patients had severe erectile problems. Dose escalation in prostate cancer by either 3-DC boost to 74 Gy or HDR brachytherapy boost appears to result in similar HRQOL profiles

Inverse planning anatomy-based dose optimization for HDR-brachytherapy of the prostate using fast simulated annealing algorithm and dedicated objective function

International Nuclear Information System (INIS)

Lessard, Etienne; Pouliot, Jean

2001-01-01

An anatomy-based dose optimization algorithm is developed to automatically and rapidly produce a highly conformal dose coverage of the target volume while minimizing urethra, bladder, and rectal doses in the delivery of an high dose-rate (HDR) brachytherapy boost for the treatment of prostate cancer. The dwell times are optimized using an inverse planning simulated annealing algorithm (IPSA) governed entirely from the anatomy extracted from a CT and by a dedicated objective function (cost function) reflecting clinical prescription and constraints. With this inverse planning approach, the focus is on the physician's prescription and constraint instead of on the technical limitations. Consequently, the physician's control on the treatment is improved. The capacity of this algorithm to represent the physician's prescription is presented for a clinical prostate case. The computation time (CPU) for IPSA optimization is less than 1 min (41 s for 142 915 iterations) for a typical clinical case, allowing fast and practical dose optimization. The achievement of highly conformal dose coverage to the target volume opens the possibility to deliver a higher dose to the prostate without inducing overdosage of urethra and normal tissues surrounding the prostate. Moreover, using the same concept, it will be possible to deliver a boost dose to a delimited tumor volume within the prostate. Finally, this method can be easily extended to other anatomical sites

Automated high-dose rate brachytherapy treatment planning for a single-channel vaginal cylinder applicator

Science.gov (United States)

Zhou, Yuhong; Klages, Peter; Tan, Jun; Chi, Yujie; Stojadinovic, Strahinja; Yang, Ming; Hrycushko, Brian; Medin, Paul; Pompos, Arnold; Jiang, Steve; Albuquerque, Kevin; Jia, Xun

2017-06-01

High dose rate (HDR) brachytherapy treatment planning is conventionally performed manually and/or with aids of preplanned templates. In general, the standard of care would be elevated by conducting an automated process to improve treatment planning efficiency, eliminate human error, and reduce plan quality variations. Thus, our group is developing AutoBrachy, an automated HDR brachytherapy planning suite of modules used to augment a clinical treatment planning system. This paper describes our proof-of-concept module for vaginal cylinder HDR planning that has been fully developed. After a patient CT scan is acquired, the cylinder applicator is automatically segmented using image-processing techniques. The target CTV is generated based on physician-specified treatment depth and length. Locations of the dose calculation point, apex point and vaginal surface point, as well as the central applicator channel coordinates, and the corresponding dwell positions are determined according to their geometric relationship with the applicator and written to a structure file. Dwell times are computed through iterative quadratic optimization techniques. The planning information is then transferred to the treatment planning system through a DICOM-RT interface. The entire process was tested for nine patients. The AutoBrachy cylindrical applicator module was able to generate treatment plans for these cases with clinical grade quality. Computation times varied between 1 and 3 min on an Intel Xeon CPU E3-1226 v3 processor. All geometric components in the automated treatment plans were generated accurately. The applicator channel tip positions agreed with the manually identified positions with submillimeter deviations and the channel orientations between the plans agreed within less than 1 degree. The automatically generated plans obtained clinically acceptable quality.

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)

Computed tomography-based treatment planning for high-dose-rate brachytherapy using the tandem and ring applicator: influence of applicator choice on organ dose and inter-fraction adaptive planning

Directory of Open Access Journals (Sweden)

Vishruta A. Dumane

2017-06-01

Full Text Available Three dimensional planning for high-dose-rate (HDR brachytherapy in cervical cancer has been highly recommended by consensus guidelines such as the American Brachytherapy Society (ABS and the Groupe Européen de Curiethérapie – European Society for Radiotherapy and Oncology (GEC-ESTRO. In this document, we describe our experience with computed tomography (CT-based planning using the tandem/ring applicator. We discuss the influence of applicator geometry on doses to organs at risk (OARs, namely the bladder, rectum, and sigmoid. Through example cases with dose prescribed to point A, we demonstrate how adaptive planning can help achieve constraints to the OARs as per guidelines.

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)

Comparison of different treatment planning optimization methods for vaginal HDR brachytherapy with multichannel applicators: A reduction of the high doses to the vaginal mucosa is possible.

Science.gov (United States)

Carrara, Mauro; Cusumano, Davide; Giandini, Tommaso; Tenconi, Chiara; Mazzarella, Ester; Grisotto, Simone; Massari, Eleonora; Mazzeo, Davide; Cerrotta, Annamaria; Pappalardi, Brigida; Fallai, Carlo; Pignoli, Emanuele

2017-12-01

A direct planning approach with multi-channel vaginal cylinders (MVCs) used for HDR brachytherapy of vaginal cancers is particularly challenging. Purpose of this study was to compare the dosimetric performances of different forward and inverse methods used for the optimization of MVC-based vaginal treatments for endometrial cancer, with a particular attention to the definition of strategies useful to limit the high doses to the vaginal mucosa. Twelve postoperative vaginal HDR brachytherapy treatments performed with MVCs were considered. Plans were retrospectively optimized with three different methods: Dose Point Optimization followed by Graphical Optimization (DPO + GrO), Inverse Planning Simulated Annealing with two different class solutions as starting conditions (surflPSA and homogIPSA) and Hybrid Inverse Planning Optimization (HIPO). Several dosimetric parameters related to target coverage, hot spot extensions and sparing of organs at risk were analyzed to evaluate the quality of the achieved treatment plans. Dose homogeneity index (DHI), conformal index (COIN) and a further parameter quantifying the proportion of the central catheter loading with respect to the overall loading (i.e., the central catheter loading index: CCLI) were also quantified. The achieved PTV coverage parameters were highly correlated with each other but uncorrelated with the hot spot quantifiers. HomogIPSA and HIPO achieved higher DHIs and CCLIs and lower volumes of high doses than DPO + GrO and surflPSA. Within the investigated optimization methods, HIPO and homoglPSA showed the highest dose homogeneity to the target. In particular, homogIPSA resulted also the most effective in reducing hot spots to the vaginal mucosa. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

SU-F-T-61: Treatment Planning Observations for the CivaSheet Directional Brachytherapy Device Using VariSeed 9.0

Energy Technology Data Exchange (ETDEWEB)

Rivard, MJ [Tufts University School of Medicine, Boston, MA (United States); Rothley, DJ [Cancer Treatment Centers of America, Newnan, GA (United States)

2016-06-15

Purpose: The VariSeed 9.0 brachytherapy TPS is recently available and has new features such as ability to rotate a brachytherapy source away from normal to the imaging plane. Consequently, a dosimetric analysis was performed for a directional brachytherapy source (CivaSheet) with tests of this functionality and experiences from clinical treatment planning were documented. These observations contribute to safe, practical, and accurate use of such new software features. Methods: Several tests were established to evaluate the new rotational feature, specific to the CivaSheet for the first patients treated using this new brachytherapy device. These included suitability of imaging slice-thickness and in-plane resolution, window/level adjustments for brachytherapy source visualization, commissioning the source physical length for performing rotations, and using different planar and 3D window views to identify source orientation. Additional CivaSheet-specific tests were performed to determine the dosimetric influence on target coverage: changing the source tilt angle, source positioning in the treatment plan based on the CivaSheet rectangular array of CivaDots, and influence of prescription depth on the necessary treatment margin for adequate target coverage. Results: Higher imaging-resolution produced better accuracy for source orientation and positioning, with sub-millimeter CT slice-thickness and in-plane resolution preferred. Source rotation was possible only in sagittal or coronal views. The process for validating source orientation required iteratively altering rotations then checking them in the 3D view, which was cumbersome given the absence of quantitative plan documentation to indicate orientation. Given the small Pd-103 source size, influence of source tilt within 30° was negligible for <1.0 cm. Influence of source position was important when the source was positioned in/out of the adjacent source plane, causing changes of 15%, 7%, and 3% at depths of 0.5, 0

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.

Mixed integer programming improves comprehensibility and plan quality in inverse optimization of prostate HDR Brachytherapy

NARCIS (Netherlands)

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

2013-01-01

Current inverse treatment planning methods that optimize both catheter positions and dwell times in prostate HDR brachytherapy use surrogate linear or quadratic objective functions that have no direct interpretation in terms of dose-volume histogram (DVH) criteria, do not result in an optimum or

Dose optimization of intra-operative high dose rate interstitial brachytherapy implants for soft tissue sarcoma

Directory of Open Access Journals (Sweden)

Jamema Swamidas

2009-01-01

Full Text Available Objective : A three dimensional (3D image-based dosimetric study to quantitatively compare geometric vs. dose-point optimization in combination with graphical optimization for interstitial brachytherapy of soft tissue sarcoma (STS. Materials and Methods : Fifteen consecutive STS patients, treated with intra-operative, interstitial Brachytherapy, were enrolled in this dosimetric study. Treatment plans were generated using dose points situated at the "central plane between the catheters", "between the catheters throughout the implanted volume", at "distances perpendicular to the implant axis" and "on the surface of the target volume" Geometrically optimized plans had dose points defined between the catheters, while dose-point optimized plans had dose points defined at a plane perpendicular to the implant axis and on the target surface. Each plan was graphically optimized and compared using dose volume indices. Results : Target coverage was suboptimal with coverage index (CI = 0.67 when dose points were defined at the central plane while it was superior when the dose points were defined at the target surface (CI=0.93. The coverage of graphically optimized plans (GrO was similar to non-GrO with dose points defined on surface or perpendicular to the implant axis. A similar pattern was noticed with conformity index (0.61 vs. 0.82. GrO were more conformal and less homogeneous compared to non-GrO. Sum index was superior for dose points defined on the surface of the target and relatively inferior for plans with dose points at other locations (1.35 vs. 1.27. Conclusions : Optimization with dose points defined away from the implant plane and on target results in superior target coverage with optimal values of other indices. GrO offer better target coverage for implants with non-uniform geometry and target volume.

MO-FG-BRA-01: Development of An Image-Guided Dosimetric Planning System for Injectable Brachytherapy Using ELP Nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Lafata, K [Duke University, Durham, North Carolina (United States); Duke University Medical Center, Durham, NC (United States); Schaal, J; Liu, W [Duke University, Durham, North Carolina (United States); Cai, J [Duke University Medical Center, Durham, NC (United States)

2015-06-15

Purpose: To develop, validate, and evaluate a methodology for determining dosimetry for intratumoral injections of elastin-like-polypeptide (ELP) brachytherapy nanoparticles. These organic-polymer-based nanoparticles are injectable, biodegradable, and genetically tunable. We present a genetically encoded polymer-solution, composed of novel radiolabeled-ELP nanoparticles that are custom-designed to self-assemble into a local source upon intratumoral injection. Our preliminary results of a small animal study demonstrate 100% tumor response, effective radionuclide retention-rates, strong in vivo stability, and no polymer-induced toxicities. While our approach is therefore highly promising for improved brachytherapy, the current workflow lacks a dosimetry framework. Methods: We are developing a robust software framework that provides image-guided dosimetric-planning capabilities for ELP brachytherapy. The user graphically places ELP injection sites within a µCT-planning-image, and independently defines each injection volume, concentration, and radioisotope to be used. The resulting internal dosimetry is then pre-determined by first modeling post-injection ELP advection-diffusion, and then calculating the resulting dose distribution based on a point- dose-kernel-convolution algorithm. We have experimentally measured ELP steady-state concentrations via µSPECT acquisition, and validated our dose calculation algorithm against Monte Carlo simulations of several radioactivity distributions. Finally, we have investigated potential advantages and limitations of various ELP injection parameters. Results: The µSPECT results demonstrated inhomogeneous steady-state distributions of ELP in tissue, and Monte Carlo radioactivity distributions were designed accordingly. Our algorithm yielded a root-mean-square-error of less than 2% for each distribution tested (average root-mean-square-error was 0.73%). Dose-Volume-Histogram analysis of five different plans showed how strategic

New inverse planning technology for image-guided cervical cancer brachytherapy: Description and evaluation within a clinical frame

International Nuclear Information System (INIS)

Trnkova, Petra; Poetter, Richard; Baltas, Dimos; Karabis, Andreas; Fidarova, Elena; Dimopoulos, Johannes; Georg, Dietmar; Kirisits, Christian

2009-01-01

Purpose: To test the feasibility of a new inverse planning technology based on the Hybrid Inverse treatment Planning and Optimisation (HIPO) algorithm for image-guided cervical cancer brachytherapy in comparison to conventional manual optimisation as applied in recent clinical practice based on long-term intracavitary cervical cancer brachytherapy experience. Materials and methods: The clinically applied treatment plans of 10 tandem/ring (T/R) and 10 cases with additional needles (T/R + N) planned with PLATO v14.3 were included. Standard loading patterns were manually optimised to reach an optimal coverage with 7 Gy per fraction to the High Risk CTV and to fulfil dose constraints for organs at risk. For each of these patients an inverse plan was retrospectively created with Oncentra GYN v0.9.14. Anatomy based automatic source activation was based on the topography of target and organs. The HIPO algorithm included individual gradient and modification restrictions for the T/R and needle dwell times to preserve the spatial high-dose distribution as known from the long-term clinical experience in the standard cervical cancer brachytherapy and with manual planning. Results: HIPO could achieve a better target coverage (V100) for all T/R and 7 T/R + N patients. Changes in the shape of the overdose volume (V200/400) were limited. The D 2cc per fraction for bladder, rectum and sigmoid colon was on average lower by 0.2 Gy, 0.4 Gy, 0.2 Gy, respectively, for T/R patients and 0.6 Gy, 0.3 Gy, 0.3 Gy for T/R + N patients (a decrease from 4.5 to 4 Gy per fraction means a total dose reduction of 5 Gy EQD2 for a 4-fraction schedule). In general the dwell times in the additional needles were lower compared to manual planning. The sparing factors were always better for HIPO plans. Additionally, in 7 T/R and 7 T/R + N patients all three D 0.1cc , D 1cc and D 2cc for vagina wall were lower and a smaller area of vagina was covered by the reference dose in HIPO plans. Overall loading

3-D conformal treatment of prostate cancer to 74 Gy vs. high-dose-rate brachytherapy boost: A cross-sectional quality-of-life survey

Energy Technology Data Exchange (ETDEWEB)

Vordermark, Dirk [Univ. of Wuerzburg (DE). Dept. of Radiation Oncology] (and others)

2006-09-15

The effects of two modalities of dose-escalated radiotherapy on health-related quality of life (HRQOL) were compared. Forty-one consecutive patients were treated with a 3-D conformal (3-DC) boost to 74 Gy, and 43 with high-dose rate (HDR) brachytherapy boost (2x9 Gy), following 3-D conformal treatment to 46 Gy. Median age was 70 years in both groups, median initial PSA was 7.9 {mu}g/l in 3-DC boost patients and 8.1 {mu}g/l in HDR boost patients. Stage was 7 in 52% and 47%, respectively. HRQOL was assessed cross-sectionally using EORTC QLQ-C30 and organ-specific PR25 modules 3-32 (median 19) and 4-25 (median 14) months after treatment, respectively. Questionnaires were completed by 93% and 97% of patients, respectively. Diarrhea and insomnia scores were significantly increased in both groups. In the PR25 module, scores of 3-DC boost and HDR boost patients for urinary, bowel and treatment-related symptoms were similar. Among responders, 34% of 3-DC boost patients and 86% of HDR boost patients had severe erectile problems. Dose escalation in prostate cancer by either 3-DC boost to 74 Gy or HDR brachytherapy boost appears to result in similar HRQOL profiles.

WE-F-BRD-01: HDR Brachytherapy II: Integrating Imaging with HDR

International Nuclear Information System (INIS)

Craciunescu, O; Todor, D; Leeuw, A de

2014-01-01

In recent years, with the advent of high/pulsed dose rate afterloading technology, advanced treatment planning systems, CT/MRI compatible applicators, and advanced imaging platforms, image-guided adaptive brachytherapy treatments (IGABT) have started to play an ever increasing role in modern radiation therapy. The most accurate way to approach IGABT treatment is to provide the infrastructure that combines in a single setting an appropriate imaging device, a treatment planning system, and a treatment unit. The Brachytherapy Suite is not a new concept, yet the modern suites are incorporating state-of-the-art imaging (MRI, CBCT equipped simulators, CT, and /or US) that require correct integration with each other and with the treatment planning and delivery systems. Arguably, an MRI-equipped Brachytherapy Suite is the ideal setup for real-time adaptive brachytherapy treatments. The main impediment to MRI-IGABT adoption is access to MRI scanners. Very few radiation oncology departments currently house MRI scanners, and even fewer in a dedicated Brachytherapy Suite. CBCT equipped simulators are increasingly offered by manufacturers as part of a Brachytherapy Suite installation. If optimized, images acquired can be used for treatment planning, or can be registered with other imaging modalities. This infrastructure is relevant for all forms of brachytherapy, especially those utilizing multi-fractionated courses of treatment such as prostate and cervix. Moreover, for prostate brachytherapy, US imaging systems can be part of the suite to allow for real-time HDR/LDR treatments. Learning Objectives: Understand the adaptive workflow of MR-based IGBT for cervical cancer. Familiarize with commissioning aspects of a CBCT equipped simulator with emphasis on brachytherapy applications Learn about the current status and future developments in US-based prostate brachytherapy

WE-F-BRD-01: HDR Brachytherapy II: Integrating Imaging with HDR

Energy Technology Data Exchange (ETDEWEB)

Craciunescu, O [Duke University Medical Center, Durham, NC (United States); Todor, D [Virginia Commonwealth University, Richmond, VA (United States); Leeuw, A de

2014-06-15

In recent years, with the advent of high/pulsed dose rate afterloading technology, advanced treatment planning systems, CT/MRI compatible applicators, and advanced imaging platforms, image-guided adaptive brachytherapy treatments (IGABT) have started to play an ever increasing role in modern radiation therapy. The most accurate way to approach IGABT treatment is to provide the infrastructure that combines in a single setting an appropriate imaging device, a treatment planning system, and a treatment unit. The Brachytherapy Suite is not a new concept, yet the modern suites are incorporating state-of-the-art imaging (MRI, CBCT equipped simulators, CT, and /or US) that require correct integration with each other and with the treatment planning and delivery systems. Arguably, an MRI-equipped Brachytherapy Suite is the ideal setup for real-time adaptive brachytherapy treatments. The main impediment to MRI-IGABT adoption is access to MRI scanners. Very few radiation oncology departments currently house MRI scanners, and even fewer in a dedicated Brachytherapy Suite. CBCT equipped simulators are increasingly offered by manufacturers as part of a Brachytherapy Suite installation. If optimized, images acquired can be used for treatment planning, or can be registered with other imaging modalities. This infrastructure is relevant for all forms of brachytherapy, especially those utilizing multi-fractionated courses of treatment such as prostate and cervix. Moreover, for prostate brachytherapy, US imaging systems can be part of the suite to allow for real-time HDR/LDR treatments. Learning Objectives: Understand the adaptive workflow of MR-based IGBT for cervical cancer. Familiarize with commissioning aspects of a CBCT equipped simulator with emphasis on brachytherapy applications Learn about the current status and future developments in US-based prostate brachytherapy.

[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.

Can the prostate brachytherapy by permanent implants represent an alternative to external radiotherapy for the localised prostate cancers with intermediary risk?

International Nuclear Information System (INIS)

Farnault, B.; Duberge, T.; Salem, N.; Boher, J.M.; Gravis, G.; Bladou, F.; Jochen, W.; Resbeut, M.

2009-01-01

Purpose: the prostate brachytherapy stands out as treatment of low risk prostate cancers, but the data concerning its use as exclusive treatment of intermediary risk prostate cancer are rare. We present a retrospective analysis of intermediary risk prostate cancers which treatment was either an external conformal radiotherapy or an exclusive brachytherapy. conclusion: In this mono centric series, the brachytherapy brings excellent results in comparison with external conformal radiotherapy with dose escalation and could be proposed as alternative to patients suffering of intermediary risk prostate cancer. (N.C.)

Permanent Seed Implant Dosimetry (PSID)TM 4.5 version as isodose and Treatment Planning System (TPS) programme for brachytherapy

International Nuclear Information System (INIS)

Indra Saptiama; Moch Subechi; Anung Pujiyanto; Hotman Lubis; Herlan Setiawan

2014-01-01

The medical treatment using radiation therapy for cancer diseases is increasingly developed. One of the method used in radiotherapy is brachytherapy. Brachytherapy is radiation therapy method in which a radiation source is implanted in cancer cell directly so the dose accepted by cancer cell is the highest dose and the dose accepted by normal cell is the lowest dose. I-125 Seed have been made successfully in domestic. To support the implant of I-125 seed for brachytherapy needs computer programme for the isodose calculation and Treatment Planning System (TPS). Permanent Seed Implant Dosimetry (PSID) 4.5 is one of the isodose calculation and Treatment Planning System (TPS) programme that is owned by Center for Radioisotope and Radiopharmaceutical-BATAN. In isodose calculation, PSID 4.5 uses 1D formalism and 2D formalism based on AAPM-TG43 (Association of American Physicist in Medicine- Task Group No.43). Anisotropic function on 1D formalism depend on distance function while on 2D formalism count on distance and angle function therefore 2D formalism has isodose calculation better than 1D formalism usage. PSID 4.5 can display the isodose contour of the seed I-125 radiation source in 2 dimension (2D) and 3 dimension (3D). The computer programme of isodose calculation and TPS uses PSID 4.5 is expected able to help planning for seed I-125 implantation process for brachytherapy that used by paramedics and to support the usage of seed I-125 as domestic product. (author)

SU-F-T-37: Dosimetric Evaluation of Planned Versus Decay Corrected Treatment Plans for the Treatment of Tandem-Based Cervical HDR Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Goyal, M [Texas Oncology, PA, Fort Worth, TX (United States); Shobhit University, Meerut, Uttar Pradesh (India); Manjhi, J; Rai, D [Shobhit University, Meerut, Uttar Pradesh (India); Kehwar, T [Pinnacle Health Cancer Center, Mechanicsburg, PA (United States); Barker, J; Heintz, B; Shide, K [Texas Oncology, PA, Fort Worth, TX (United States)

2016-06-15

Purpose: This study evaluated dosimetric parameters for actual treatment plans versus decay corrected treatment plans for cervical HDR brachytherapy. Methods: 125 plans of 25 patients, who received 5 fractions of HDR brachytherapy, were evaluated in this study. Dose was prescribed to point A (ICRU-38) and High risk clinical tumor volume (HR-CTV) and organs at risk (OAR) were, retrospectively, delineated on original CT images by treating physician. First HDR plan was considered as reference plan and decay correction was applied to calculate treatment time for subsequent fractions, and was applied, retrospectively, to determine point A, HR-CTV D90, and rectum and bladder doses. Results: The differences between mean point A reference doses and the point A doses of the plans computed using decay times were found to be 1.05%±0.74% (−2.26% to 3.26%) for second fraction; −0.25%±0.84% (−3.03% to 3.29%) for third fraction; 0.04%±0.70% (−2.68% to 2.56%) for fourth fraction and 0.30%±0.81% (−3.93% to 2.67%) for fifth fraction. Overall mean point A dose difference, for all fractions, was 0.29%±0.38% (within ± 5%). Mean rectum and bladder dose differences were calculated to be −3.46%±0.12% and −2.47%±0.09%, for points, respectively, and −1.72%±0.09% and −0.96%±0.06%, for D2cc, respectively. HR-CTV D90 mean dose difference was found to be −1.67% ± 0.11%. There was no statistically significant difference between the reference planned point A doses and that calculated using decay time to the subsequent fractions (p<0.05). Conclusion: This study reveals that a decay corrected treatment will provide comparable dosimetric results and can be utilized for subsequent fractions of cervical HDR brachytherapy instead of actual treatment planning. This approach will increase efficiency, decrease workload, reduce patient observation time between applicator insertion and treatment delivery. This would be particularly useful for institutions with limited

Verification of dosimetry planning in brachytherapy in format Dicom and EUD calculation of Risk in bodies

International Nuclear Information System (INIS)

Garcia Hernandez, M. J.; Sendon del Rio, J. R.; Ayala Lazaro, R.; Jimenez Rojas, M. R.; Gomez Cores, S.; Polo Cezon, R.; Lopez Bote, M. A.

2013-01-01

This work Describes a program that automates the verification of the schedules in brachytherapy (configuration and dosimetric treatment parameters) for sources of Ir-192 (mHDR v2) and Co-60 (Co0.A86) from the plan exported in DICOM format data. (Author)

94: Treatment plan optimization for conformal therapy

International Nuclear Information System (INIS)

Rosen, I.I.; Lane, R.G.

1987-01-01

Computer-controlled conformal radiation therapy techniques can deliver complex treatments utilizing large numbers of beams, gantry angles and beam shapes. Linear programming is well-suited for planning conformal treatments. Given a list of available treatment beams, linear programming calculates the relative weights of the beams such that the objective function is optimized and doses to constraint points are within the prescribed limits. 5 refs.; 3 figs

Evaluation of a Machine-Learning Algorithm for Treatment Planning in Prostate Low-Dose-Rate Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Nicolae, Alexandru [Department of Physics, Ryerson University, Toronto, Ontario (Canada); Department of Medical Physics, Odette Cancer Center, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Morton, Gerard; Chung, Hans; Loblaw, Andrew [Department of Radiation Oncology, Odette Cancer Center, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Jain, Suneil; Mitchell, Darren [Department of Clinical Oncology, The Northern Ireland Cancer Centre, Belfast City Hospital, Antrim, Northern Ireland (United Kingdom); Lu, Lin [Department of Radiation Therapy, Odette Cancer Center, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Helou, Joelle; Al-Hanaqta, Motasem [Department of Radiation Oncology, Odette Cancer Center, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Heath, Emily [Department of Physics, Carleton University, Ottawa, Ontario (Canada); Ravi, Ananth, E-mail: ananth.ravi@sunnybrook.ca [Department of Medical Physics, Odette Cancer Center, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada)

2017-03-15

Purpose: This work presents the application of a machine learning (ML) algorithm to automatically generate high-quality, prostate low-dose-rate (LDR) brachytherapy treatment plans. The ML algorithm can mimic characteristics of preoperative treatment plans deemed clinically acceptable by brachytherapists. The planning efficiency, dosimetry, and quality (as assessed by experts) of preoperative plans generated with an ML planning approach was retrospectively evaluated in this study. Methods and Materials: Preimplantation and postimplantation treatment plans were extracted from 100 high-quality LDR treatments and stored within a training database. The ML training algorithm matches similar features from a new LDR case to those within the training database to rapidly obtain an initial seed distribution; plans were then further fine-tuned using stochastic optimization. Preimplantation treatment plans generated by the ML algorithm were compared with brachytherapist (BT) treatment plans in terms of planning time (Wilcoxon rank sum, α = 0.05) and dosimetry (1-way analysis of variance, α = 0.05). Qualitative preimplantation plan quality was evaluated by expert LDR radiation oncologists using a Likert scale questionnaire. Results: The average planning time for the ML approach was 0.84 ± 0.57 minutes, compared with 17.88 ± 8.76 minutes for the expert planner (P=.020). Preimplantation plans were dosimetrically equivalent to the BT plans; the average prostate V150% was 4% lower for ML plans (P=.002), although the difference was not clinically significant. Respondents ranked the ML-generated plans as equivalent to expert BT treatment plans in terms of target coverage, normal tissue avoidance, implant confidence, and the need for plan modifications. Respondents had difficulty differentiating between plans generated by a human or those generated by the ML algorithm. Conclusions: Prostate LDR preimplantation treatment plans that have equivalent quality to plans created

Evaluation of a Machine-Learning Algorithm for Treatment Planning in Prostate Low-Dose-Rate Brachytherapy

International Nuclear Information System (INIS)

Nicolae, Alexandru; Morton, Gerard; Chung, Hans; Loblaw, Andrew; Jain, Suneil; Mitchell, Darren; Lu, Lin; Helou, Joelle; Al-Hanaqta, Motasem; Heath, Emily; Ravi, Ananth

2017-01-01

Purpose: This work presents the application of a machine learning (ML) algorithm to automatically generate high-quality, prostate low-dose-rate (LDR) brachytherapy treatment plans. The ML algorithm can mimic characteristics of preoperative treatment plans deemed clinically acceptable by brachytherapists. The planning efficiency, dosimetry, and quality (as assessed by experts) of preoperative plans generated with an ML planning approach was retrospectively evaluated in this study. Methods and Materials: Preimplantation and postimplantation treatment plans were extracted from 100 high-quality LDR treatments and stored within a training database. The ML training algorithm matches similar features from a new LDR case to those within the training database to rapidly obtain an initial seed distribution; plans were then further fine-tuned using stochastic optimization. Preimplantation treatment plans generated by the ML algorithm were compared with brachytherapist (BT) treatment plans in terms of planning time (Wilcoxon rank sum, α = 0.05) and dosimetry (1-way analysis of variance, α = 0.05). Qualitative preimplantation plan quality was evaluated by expert LDR radiation oncologists using a Likert scale questionnaire. Results: The average planning time for the ML approach was 0.84 ± 0.57 minutes, compared with 17.88 ± 8.76 minutes for the expert planner (P=.020). Preimplantation plans were dosimetrically equivalent to the BT plans; the average prostate V150% was 4% lower for ML plans (P=.002), although the difference was not clinically significant. Respondents ranked the ML-generated plans as equivalent to expert BT treatment plans in terms of target coverage, normal tissue avoidance, implant confidence, and the need for plan modifications. Respondents had difficulty differentiating between plans generated by a human or those generated by the ML algorithm. Conclusions: Prostate LDR preimplantation treatment plans that have equivalent quality to plans created

A quality assurance index for brachytherapy treatment plan verification

International Nuclear Information System (INIS)

Simpson, J.B.; Clarke, J.P.

2000-01-01

A method is described which provides an independent verification of a brachytherapy treatment plan. The method is applicable to any common geometric configuration and utilises a simple equation derived from a common form of nonlinear regression. The basis for the index value is the relationship between the treatment time, prescribed dose, source strength and plan geometry. This relationship may be described mathematically as: Total Treatment Time ∝ Prescribed Dose/Source Strength x (a geometric term) with the geometric term incorporating three geometric components, namely the distance from source positions to points of dose normalisation (d), the total length of the dwell positions (L), and the number of source trains or catheters (N). A general equation of the form GF = k (d) -α (L) -β (N) -y is used to describe the plan geometry, where GF is what we have termed the geometric factor, k is a constant of proportionality and the exponents are derived from the non-linear regression process. The resulting index is simple to calculate prior to patient treatment and sensitive enough to identify significant error whilst being robust enough to allow for a normal degree of geometric distortion

Interim report of image-guided conformal high-dose-rate brachytherapy for patients with unfavorable prostate cancer: the William Beaumont Phase II dose-escalating trial

International Nuclear Information System (INIS)

Martinez, Alvaro A.; Kestin, Larry L.; Stromberg, Jannifer S.; Gonzalez, Jose A.; Wallace, Michelle; Gustafson, Gary S.; Edmundson, Gregory K.; Spencer, William; Vicini, Frank A.

2000-01-01

Purpose: We analyzed our institution's experience treating patients with unfavorable prostate cancer in a prospective Phase II dose-escalating trial of external beam radiation therapy (EBRT) integrated with conformal high-dose-rate (HDR) brachytherapy boosts. This interim report discusses treatment outcome and prognostic factors using this treatment approach. Methods and Materials: From November 1991 through February 1998, 142 patients with unfavorable prostate cancer were prospectively treated in a dose-escalating trial with pelvic EBRT in combination with outpatient HDR brachytherapy at William Beaumont Hospital. Patients with any of the following characteristics were eligible: pretreatment prostate-specific antigen (PSA) ≥ 10.0 ng/ml, Gleason score ≥ 7, or clinical stage T2b or higher. All patients received pelvic EBRT to a median total dose of 46.0 Gy. Pelvic EBRT was integrated with ultrasound-guided transperineal conformal interstitial iridium-192 HDR implants. From 1991 to 1995, 58 patients underwent three conformal interstitial HDR implants during the first, second, and third weeks of pelvic EBRT. After October 1995, 84 patients received two interstitial implants during the first and third weeks of pelvic EBRT. The dose delivered via interstitial brachytherapy was escalated from 5.50 Gy to 6.50 Gy for each implant in those patients receiving three implants, and subsequently, from 8.25 Gy to 9.50 Gy per fraction in those patients receiving two implants. To improve implant quality and reduce operator dependency, an on-line, image-guided interactive dose optimization program was utilized during each HDR implant. No patient received hormonal therapy unless treatment failure was documented. The median follow-up was 2.1 years (range: 0.2-7.2 years). Biochemical failure was defined according to the American Society for Therapeutic Radiology and Oncology Consensus Panel definition. Results: The pretreatment PSA level was ≥ 10.0 ng/ml in 51% of patients. The

A fast inverse treatment planning strategy facilitating optimized catheter selection in image-guided high-dose-rate interstitial gynecologic brachytherapy.

Science.gov (United States)

Guthier, Christian V; Damato, Antonio L; Hesser, Juergen W; Viswanathan, Akila N; Cormack, Robert A

2017-12-01

Interstitial high-dose rate (HDR) brachytherapy is an important therapeutic strategy for the treatment of locally advanced gynecologic (GYN) cancers. The outcome of this therapy is determined by the quality of dose distribution achieved. This paper focuses on a novel yet simple heuristic for catheter selection for GYN HDR brachytherapy and their comparison against state of the art optimization strategies. The proposed technique is intended to act as a decision-supporting tool to select a favorable needle configuration. The presented heuristic for catheter optimization is based on a shrinkage-type algorithm (SACO). It is compared against state of the art planning in a retrospective study of 20 patients who previously received image-guided interstitial HDR brachytherapy using a Syed Neblett template. From those plans, template orientation and position are estimated via a rigid registration of the template with the actual catheter trajectories. All potential straight trajectories intersecting the contoured clinical target volume (CTV) are considered for catheter optimization. Retrospectively generated plans and clinical plans are compared with respect to dosimetric performance and optimization time. All plans were generated with one single run of the optimizer lasting 0.6-97.4 s. Compared to manual optimization, SACO yields a statistically significant (P ≤ 0.05) improved target coverage while at the same time fulfilling all dosimetric constraints for organs at risk (OARs). Comparing inverse planning strategies, dosimetric evaluation for SACO and "hybrid inverse planning and optimization" (HIPO), as gold standard, shows no statistically significant difference (P > 0.05). However, SACO provides the potential to reduce the number of used catheters without compromising plan quality. The proposed heuristic for needle selection provides fast catheter selection with optimization times suited for intraoperative treatment planning. Compared to manual optimization, the

Rapid emission angle selection for rotating-shield brachytherapy

International Nuclear Information System (INIS)

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

2013-01-01

Purpose: The authors present a rapid emission angle selection (REAS) method that enables the efficient selection of the azimuthal shield angle for rotating shield brachytherapy (RSBT). The REAS method produces a Pareto curve from which a potential RSBT user can select a treatment plan that balances the tradeoff between delivery time and tumor dose conformity. Methods: Two cervical cancer patients were considered as test cases for the REAS method. The RSBT source considered was a Xoft Axxent TM electronic brachytherapy source, partially shielded with 0.5 mm of tungsten, which traveled inside a tandem intrauterine applicator. Three anchor RSBT plans were generated for each case using dose-volume optimization, with azimuthal shield emission angles of 90°, 180°, and 270°. The REAS method converts the anchor plans to treatment plans for all possible emission angles by combining neighboring beamlets to form beamlets for larger emission angles. Treatment plans based on exhaustive dose-volume optimization (ERVO) and exhaustive surface optimization (ERSO) were also generated for both cases. Uniform dwell-time scaling was applied to all plans such that that high-risk clinical target volume D 90 was maximized without violating the D 2cc tolerances of the rectum, bladder, and sigmoid colon. Results: By choosing three azimuthal emission angles out of 32 potential angles, the REAS method performs about 10 times faster than the ERVO method. By setting D 90 to 85–100 Gy 10 , the delivery times used by REAS generated plans are 21.0% and 19.5% less than exhaustive surface optimized plans used by the two clinical cases. By setting the delivery time budget to 5–25 and 10–30 min/fx, respectively, for two the cases, the D 90 contributions for REAS are improved by 5.8% and 5.1% compared to the ERSO plans. The ranges used in this comparison were selected in order to keep both D 90 and the delivery time within acceptable limits. Conclusions: The REAS method enables efficient RSBT

Inverse Planned High-Dose-Rate Brachytherapy for Locoregionally Advanced Cervical Cancer: 4-Year Outcomes

Energy Technology Data Exchange (ETDEWEB)

Tinkle, Christopher L.; Weinberg, Vivian [Department of Radiation Oncology, University of California, San Francisco, California (United States); Chen, Lee-May [Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, California (United States); Littell, Ramey [Gynecologic Oncology, The Permanente Medical Group, San Francisco, California (United States); Cunha, J. Adam M.; Sethi, Rajni A. [Department of Radiation Oncology, University of California, San Francisco, California (United States); Chan, John K. [Gynecologic Oncology, California Pacific Medical Center, San Francisco, California (United States); Hsu, I-Chow, E-mail: ichow.hsu@ucsf.edu [Department of Radiation Oncology, University of California, San Francisco, California (United States)

2015-08-01

Purpose: Evaluate the efficacy and toxicity of image guided brachytherapy using inverse planning simulated annealing (IPSA) high-dose-rate brachytherapy (HDRB) boost for locoregionally advanced cervical cancer. Methods and Materials: From December 2003 through September 2009, 111 patients with primary cervical cancer were treated definitively with IPSA-planned HDRB boost (28 Gy in 4 fractions) after external radiation at our institution. We performed a retrospective review of our experience using image guided brachytherapy. Of the patients, 70% had a tumor size >4 cm, 38% had regional nodal disease, and 15% had clinically evident distant metastasis, including nonregional nodal disease, at the time of diagnosis. Surgical staging involving pelvic lymph node dissection was performed in 15% of patients, and 93% received concurrent cisplatin-based chemotherapy. Toxicities are reported according to the Common Terminology Criteria for Adverse Events version 4.0 guidelines. Results: With a median follow-up time of 42 months (range, 3-84 months), no acute or late toxicities of grade 4 or higher were observed, and grade 3 toxicities (both acute and late) developed in 8 patients (1 constitutional, 1 hematologic, 2 genitourinary, 4 gastrointestinal). The 4-year Kaplan-Meier estimate of late grade 3 toxicity was 8%. Local recurrence developed in 5 patients (4 to 9 months after HDRB), regional recurrence in 3 (6, 16, and 72 months after HDRB), and locoregional recurrence in 1 (4 months after HDR boost). The 4-year estimates of local, locoregional, and distant control of disease were 94.0%, 91.9%, and 69.1%, respectively. The overall and disease-free survival rates at 4 years were 64.3% (95% confidence interval [CI] of 54%-73%) and 61.0% (95% CI, 51%-70%), respectively. Conclusions: Definitive radiation by use of inverse planned HDRB boost for locoregionally advanced cervical cancer is well tolerated and achieves excellent local control of disease. However, overall

Novel high dose rate lip brachytherapy technique to improve dose homogeneity and reduce toxicity by customized mold

International Nuclear Information System (INIS)

Feldman, Jon; Appelbaum, Limor; Sela, Mordechay; Voskoboinik, Ninel; Kadouri, Sarit; Weinberger, Jeffrey; Orion, Itzhak; Meirovitz, Amichay

2014-01-01

The purpose of this study is to describe a novel brachytherapy technique for lip Squamous Cell Carcinoma, utilizing a customized mold with embedded brachytherapy sleeves, which separates the lip from the mandible, and improves dose homogeneity. Seven patients with T2 lip cancer treated with a “sandwich” technique of High Dose Rate (HDR) brachytherapy to the lip, consisting of interstitial catheters and a customized mold with embedded catheters, were reviewed for dosimetry and outcome using 3D planning. Dosimetric comparison was made between the “sandwich” technique to “classic” – interstitial catheters only plan. We compared dose volume histograms for Clinical Tumor Volume (CTV), normal tissue “hot spots” and mandible dose. We are reporting according to the ICRU 58 and calculated the Conformal Index (COIN) to show the advantage of our technique. The seven patients (ages 36–81 years, male) had median follow-up of 47 months. Four patients received Brachytherapy and External Beam Radiation Therapy, 3 patients received brachytherapy alone. All achieved local control, with excellent esthetic and functional results. All patients are disease free. The Customized Mold Sandwich technique (CMS) reduced the high dose region receiving 150% (V150) by an average of 20% (range 1–47%), The low dose region (les then 90% of the prescribed dose) improved by 73% in average by using the CMS technique. The COIN value for the CMS was in average 0.92 as opposed to 0.88 for the interstitial catheter only. All differences (excluding the low dose region) were statistically significant. The CMS technique significantly reduces the high dose volume and increases treatment homogeneity. This may reduce the potential toxicity to the lip and adjacent mandible, and results in excellent tumor control, cosmetic and functionality

A study on a comparative analysis of 2D and 3D planning using CT simulator for transbronchial brachytherapy

International Nuclear Information System (INIS)

Seo, Dong Rin; Kim, Dae Sup; Back, Geum Mun

2013-01-01

Transbronchial brachytherapy used in the two-dimensional treatment planning difficult to identify the location of the tumor in the affected area to determine the process analysis. In this study, we have done a comparative analysis for the patient's treatment planning using a CT simulator. The analysis was performed by the patients who visited the hospital to June 2012. The patient carried out CT-image by CT simulator, and we were plan to compare with a two-dimensional and three dimensional treatment planning using a Oncentra Brachy planning system (Nucletron, Netherlands). The location of the catheter was confirmed the each time on a treatment planning for fractionated transbronchial brachytherapy. GTV volumes were 3.5 cm 3 and 3.3 cm 3 . Also easy to determine the dose distribution of the tumor, the errors of a dose delivery were confirmed dose distribution of the prescribed dose for GTV. In the first treatment was 92% and the second was 88%. In order to compensate for the problem through a two-dimensional treatment planning, it is necessary to be tested process for the accurate identification and analysis of the treatment volume and dose distribution. Quantitatively determine the dose delivery error process that is reflected to the treatment planning is required

A study on a comparative analysis of 2D and 3D planning using CT simulator for transbronchial brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Seo, Dong Rin; Kim, Dae Sup; Back, Geum Mun [Dept. of Radiation Oncology, Asan Medical Center, Seoul (Korea, Republic of)

2013-03-15

Transbronchial brachytherapy used in the two-dimensional treatment planning difficult to identify the location of the tumor in the affected area to determine the process analysis. In this study, we have done a comparative analysis for the patient's treatment planning using a CT simulator. The analysis was performed by the patients who visited the hospital to June 2012. The patient carried out CT-image by CT simulator, and we were plan to compare with a two-dimensional and three dimensional treatment planning using a Oncentra Brachy planning system (Nucletron, Netherlands). The location of the catheter was confirmed the each time on a treatment planning for fractionated transbronchial brachytherapy. GTV volumes were 3.5 cm{sup 3} and 3.3 cm{sup 3}. Also easy to determine the dose distribution of the tumor, the errors of a dose delivery were confirmed dose distribution of the prescribed dose for GTV. In the first treatment was 92% and the second was 88%. In order to compensate for the problem through a two-dimensional treatment planning, it is necessary to be tested process for the accurate identification and analysis of the treatment volume and dose distribution. Quantitatively determine the dose delivery error process that is reflected to the treatment planning is required.

Intraoperative HDR brachytherapy for rectal cancer using a flexible intraoperative template: standard plans versus individual planning

International Nuclear Information System (INIS)

Kolkman-Deurloo, Inger-Karine K.; Nuyttens, Joost J.; Hanssens, Patrick E.J.; Levendag, Peter C.

2004-01-01

HDR intraoperative brachytherapy (IOBT) is applied to locally advanced rectal tumors using a 5 mm thick flexible intraoperative template (FIT). To reduce the procedure time, treatment planning is performed using standard plans that neglect the curvature of the FIT. We have calculated the individual treatment plan, based on the real geometry of the FIT, and the dose at clips placed during surgery. A mean treatment dose of 9.55±0.21 Gy was found for the individual plan, compared to the prescribed 10 Gy (P<0.0001). The mean central dose was 10.03±0.10 Gy in the standard plan and 9.20±0.32 Gy in the individual plan (P<0.0001). The mean dose at the corners of the FIT was 10.3 Gy in the standard plan and ranged between 10.3 and 10.5 Gy in the individual plan. In 63% of the clips, the dose was larger than 15.0 Gy, which is equivalent to a gap between the FIT and the target smaller than 5 mm. In 18% of the clips, the dose was smaller than 13.0 Gy indicating that locally the gap was larger than 5 mm. Clinical practice will have to prove if these small dose deviations influence the clinical outcome

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

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)

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.

Placement of empty catheters for an HDR-emulating LDR prostate brachytherapy technique: comparison to standard intraoperative planning.

Science.gov (United States)

Niedermayr, Thomas R; Nguyen, Paul L; Murciano-Goroff, Yonina R; Kovtun, Konstantin A; Neubauer Sugar, Emily; Cail, Daniel W; O'Farrell, Desmond A; Hansen, Jorgen L; Cormack, Robert A; Buzurovic, Ivan; Wolfsberger, Luciant T; O'Leary, Michael P; Steele, Graeme S; Devlin, Philip M; Orio, Peter F

2014-01-01

We sought to determine whether placing empty catheters within the prostate and then inverse planning iodine-125 seed locations within those catheters (High Dose Rate-Emulating Low Dose Rate Prostate Brachytherapy [HELP] technique) would improve concordance between planned and achieved dosimetry compared with a standard intraoperative technique. We examined 30 consecutive low dose rate prostate cases performed by standard intraoperative technique of planning followed by needle placement/seed deposition and compared them to 30 consecutive low dose rate prostate cases performed by the HELP technique. The primary endpoint was concordance between planned percentage of the clinical target volume that receives at least 100% of the prescribed dose/dose that covers 90% of the volume of the clinical target volume (V100/D90) and the actual V100/D90 achieved at Postoperative Day 1. The HELP technique had superior concordance between the planned target dosimetry and what was actually achieved at Day 1 and Day 30. Specifically, target D90 at Day 1 was on average 33.7 Gy less than planned for the standard intraoperative technique but was only 10.5 Gy less than planned for the HELP technique (p 0.05). Placing empty needles first and optimizing the plan to the known positions of the needles resulted in improved concordance between the planned and the achieved dosimetry to the target, possibly because of elimination of errors in needle placement. Copyright © 2014 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Monte Carlo conformal treatment planning as an independent assessment

International Nuclear Information System (INIS)

Rincon, M.; Leal, A.; Perucha, M.; Carrasco, E.; Sanchez-Doblado, F.; Hospital Univ. Virgen Macarena, Sevilla; Arrans, R.; Sanchez-Calzado, J.A.; Errazquin, L.; Medrano, J.C.

2001-01-01

The wide range of possibilities available in Radiotherapy with conformal fields cannot be covered experimentally. For this reason, dosimetrical and planning procedures are based on approximate algorithms or systematic measurements. Dose distribution calculations based on Monte Carlo (MC) simulations can be used to check results. In this work, two examples of conformal field treatments are shown: A prostate carcinoma and an ocular lymphoma. The dose distributions obtained with a conventional Planning System and with MC have been compared. Some significant differences have been found. (orig.)

Reconstruction of MRI/CT compatible ring and tandem applicators in CT or MRI images used for treatment planning in brachytherapy

International Nuclear Information System (INIS)

Surendran, N.; Kim, Hayeon; Beriwal, Sushil; Saiful Huq, M.

2008-01-01

Brachytherapy (BT) plays a crucial role in the management of invasive cervix cancer from stage I to IV. Intracavitary techniques are based on afterloading devices, with different types of applicators. CT and/or MRI compatible applicators allow a sectional image based approach with a better assessment of gross tumour volume (GTV) and definition and delineation of target volume (CTV) compared to traditional approaches. To evaluate reconstruction of MRI/CT compatible ring and tandem applicators in 3D CT or MRI images used for treatment planning in Brachytherapy

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.

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.

Conformal Radiotherapy: Physics, Treatment Planning and Verification. Proceedings book

Energy Technology Data Exchange (ETDEWEB)

De Wagter, C [ed.

1995-12-01

The goal of conformal radiotherapy is to establish radiation dose distributions that conform tightly to the target volume in view of limiting radiation to normal tissues. Conformal radiotherapy significantly improves both local control and palliation and thus contributes to increase survival and to improve the quality of life. The subjects covered by the symposium include : (1) conformal radiotherapy and multi-leaf collimation; (2) three dimensional imaging; (3) treatment simulation, planning and optimization; (4) quality assurance; and (5) dosimetry. The book of proceedings contains the abstracts of the invited lectures, papers and poster presentations as well as the full papers of these contributions.

Conformal Radiotherapy: Physics, Treatment Planning and Verification. Proceedings book

International Nuclear Information System (INIS)

De Wagter, C.

1995-12-01

The goal of conformal radiotherapy is to establish radiation dose distributions that conform tightly to the target volume in view of limiting radiation to normal tissues. Conformal radiotherapy significantly improves both local control and palliation and thus contributes to increase survival and to improve the quality of life. The subjects covered by the symposium include : (1) conformal radiotherapy and multi-leaf collimation; (2) three dimensional imaging; (3) treatment simulation, planning and optimization; (4) quality assurance; and (5) dosimetry. The book of proceedings contains the abstracts of the invited lectures, papers and poster presentations as well as the full papers of these contributions

SU-E-T-538: Lung SBRT Dosimetric Comparison of 3D Conformal and RapidArc Planning

International Nuclear Information System (INIS)

Jiang, R; Zhan, L; Osei, E

2015-01-01

Purpose: Dose distributions of RapidArc Plan can be quite different from standard 3D conformal radiation therapy. SBRT plans can be optimized with high conformity or mimic the 3D conformal treatment planning with very high dose in the center of the tumor. This study quantifies the dosimetric differences among 3D conformal plan; flattened beam and FFF beam RapidArc Plans for lung SBRT. Methods: Five lung cancer patients treated with 3D non-coplanar SBRT were randomly selected. All the patients were CT scanned with 4DCT to determine the internal target volume. Abdominal compression was applied to minimize respiratory motion for SBRT patients. The prescription dose was 48 Gy in 4 fractions. The PTV coverage was optimized by two groups of objective function: one with high conformity, another mimicking 3D conformal dose distribution with high dose in the center of PTV. Optimization constraints were set to meet the criteria of the RTOG-0915 protocol. All VMAT plans were optimized with the RapidArc technique using four full arcs in Eclipse treatment planning system. The RapidArc SBRT plans with flattened 6MV beam and 6MV FFF beam were generated and dosimetric results were compared with the previous treated 3D non-coplanar plans. Results: All the RapidArc plans with flattened beam and FFF beam had similar results for the PTV and OARs. For the high conformity optimization group, The DVH of PTV exhibited a steep dose fall-off outside the PTV compared to the 3D non-coplanar plan. However, for the group mimicking the 3D conformal target dose distribution, although the PTV is very similar to the 3D conformal plan, the ITV coverage is better than 3D conformal plan. Conclusion: Due to excellent clinical experiences of 3D conformal SBRT treatment, the Rapid Arc optimization mimicking 3D conformal planning may be suggested for clinical use

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

International Nuclear Information System (INIS)

Joseph, F Maria; Podder, T; Yu, Y

2015-01-01

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

SU-F-T-48: Clinical Implementation of Brachytherapy Planning System for COMS Eye Plaques

International Nuclear Information System (INIS)

Ferreira, C; Islam, M; Ahmad, S; De La Fuente Herman, T

2016-01-01

Purpose: To commission the Brachytherapy Planning (BP) system (Varian, Palo Alto, CA) for the Collaborative Ocular Melanoma Study (COMS) eye plaques by evaluating dose differences against original plans from Nucletron Planning System (NPS). Methods: NPS system is the primary planning software for COMS-plaques at our facility; however, Brachytherapy Planning 11.0.47 (Varian Medical Systems) is used for secondary check and for seed placement configurations not originally commissioned. Dose comparisons of BP and NPS plans were performed for prescription of 8500 cGy at 5 mm depth and doses to normal structures: opposite retina, inner sclera, macula, optic disk and lens. Plans were calculated for Iodine-125 seeds (OncoSeeds, Model 6711) using COMS-plaques of 10, 12, 14, 16, 18 and 20 mm diameters. An in-house program based on inverse-square was utilized to calculate point doses for comparison as well. Results: The highest dose difference between BP and NPS was 3.7% for the prescription point for all plaques. Doses for BP were higher than doses reported by NPS for all points. The largest percent differences for apex, opposite retina, inner sclera, macula, optic disk, and lens were 3.2%, 0.9%, 13.5%, 20.5%, 15.7% and 2.2%, respectively. The dose calculated by the in-house program was 1.3% higher at the prescription point, and were as high as 42.1%, for points away from the plaque (i.e. opposite retina) when compared to NPS. Conclusion: Doses to the tumor, lens, retina, and optic nerve are paramount for a successful treatment and vision preservation. Both systems are based on TG-43 calculations and assume water medium tissue homogeneity (ρe=1, water medium). Variations seen may result from the different task group versions and/or mathematical algorithms of the software. BP was commissioned to serve as a backup system and it also enables dose calculation in cases where seeds don’t follow conventional placement configuration.

SU-F-T-48: Clinical Implementation of Brachytherapy Planning System for COMS Eye Plaques

Energy Technology Data Exchange (ETDEWEB)

Ferreira, C; Islam, M; Ahmad, S; De La Fuente Herman, T [University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

2016-06-15

Purpose: To commission the Brachytherapy Planning (BP) system (Varian, Palo Alto, CA) for the Collaborative Ocular Melanoma Study (COMS) eye plaques by evaluating dose differences against original plans from Nucletron Planning System (NPS). Methods: NPS system is the primary planning software for COMS-plaques at our facility; however, Brachytherapy Planning 11.0.47 (Varian Medical Systems) is used for secondary check and for seed placement configurations not originally commissioned. Dose comparisons of BP and NPS plans were performed for prescription of 8500 cGy at 5 mm depth and doses to normal structures: opposite retina, inner sclera, macula, optic disk and lens. Plans were calculated for Iodine-125 seeds (OncoSeeds, Model 6711) using COMS-plaques of 10, 12, 14, 16, 18 and 20 mm diameters. An in-house program based on inverse-square was utilized to calculate point doses for comparison as well. Results: The highest dose difference between BP and NPS was 3.7% for the prescription point for all plaques. Doses for BP were higher than doses reported by NPS for all points. The largest percent differences for apex, opposite retina, inner sclera, macula, optic disk, and lens were 3.2%, 0.9%, 13.5%, 20.5%, 15.7% and 2.2%, respectively. The dose calculated by the in-house program was 1.3% higher at the prescription point, and were as high as 42.1%, for points away from the plaque (i.e. opposite retina) when compared to NPS. Conclusion: Doses to the tumor, lens, retina, and optic nerve are paramount for a successful treatment and vision preservation. Both systems are based on TG-43 calculations and assume water medium tissue homogeneity (ρe=1, water medium). Variations seen may result from the different task group versions and/or mathematical algorithms of the software. BP was commissioned to serve as a backup system and it also enables dose calculation in cases where seeds don’t follow conventional placement configuration.

SU-G-201-11: Exploring the Upper Limits of Dose Sculpting Capacity of the Novel Direction Modulated Brachytherapy (DMBT) Tandem Applicator

International Nuclear Information System (INIS)

Han, D; Safigholi, H; Soliman, A; Song, W

2016-01-01

Purpose: To explore and quantify the upper limits in dose sculpting capacity of the novel direction modulated brachytherapy (DMBT) tandem applicator compared with conventional tandem design for "1"9"2Ir-based HDR planning. Methods: The proposed DMBT tandem applicator is designed for image-guided adaptive brachytherapy (IGABT), especially MRI, of cervical cancer. It has 6 peripheral holes of 1.3-mm width, grooved along a 5.4-mm diameter nonmagnetic tungsten alloy rod of density 18.0 g/cc, capable of generating directional dose profiles – leading to enhanced dose sculpting capacity through inverse planning. The external dimensions are identical to that of conventional tandem design to ensure clinical compatibility. To explore the expansive dose sculpting capacity, we constructed a hypothetical circular target with 20-mm radius and positioned the DMBT and conventional tandems at the center. We then incrementally shifted the positions laterally away from the center of up to 15 mm, at 1-mm steps. The in-house coded gradient projection-based inverse planning system was then used to generate inverse optimized plans ensuring identical V100=100% coverage. Conformity index (CI) was calculated for all plans. Results: Overall, the DMBT tandem generates more conformal dose distributions than conventional tandem for all lateral positional shifts of 0-15 mm (CI=0.91–0.52 and 0.99–0.34, respectively), with an exception at the central position due to the ideal circular dose distribution, generated by the "1"9"2Ir, fitting tightly around the circular target (CI = 0.91 and 0.99, respectively). The DMBT tandem is able to generate dose conformity of CI>0.8 at up to 6-mm positional shift while the conventional tandem violates this past 2-mm shift. Also, the CI ratio (=DMBT/conv.) increases rapidly until about 8 mm and then stabilizes beyond. Conclusion: A substantial enhancement in the dose sculpting capacity has been demonstrated for the novel DMBT tandem applicator. While

SU-G-201-11: Exploring the Upper Limits of Dose Sculpting Capacity of the Novel Direction Modulated Brachytherapy (DMBT) Tandem Applicator

Energy Technology Data Exchange (ETDEWEB)

Han, D [University of California San Francisco, San Francisco, CA (United States); Department of Medical Physics, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON (Canada); Safigholi, H; Soliman, A [Department of Medical Physics, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON (Canada); Song, W [Department of Medical Physics, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON (Canada); University of Toronto, Toronto, ON (Canada)

2016-06-15

Purpose: To explore and quantify the upper limits in dose sculpting capacity of the novel direction modulated brachytherapy (DMBT) tandem applicator compared with conventional tandem design for {sup 192}Ir-based HDR planning. Methods: The proposed DMBT tandem applicator is designed for image-guided adaptive brachytherapy (IGABT), especially MRI, of cervical cancer. It has 6 peripheral holes of 1.3-mm width, grooved along a 5.4-mm diameter nonmagnetic tungsten alloy rod of density 18.0 g/cc, capable of generating directional dose profiles – leading to enhanced dose sculpting capacity through inverse planning. The external dimensions are identical to that of conventional tandem design to ensure clinical compatibility. To explore the expansive dose sculpting capacity, we constructed a hypothetical circular target with 20-mm radius and positioned the DMBT and conventional tandems at the center. We then incrementally shifted the positions laterally away from the center of up to 15 mm, at 1-mm steps. The in-house coded gradient projection-based inverse planning system was then used to generate inverse optimized plans ensuring identical V100=100% coverage. Conformity index (CI) was calculated for all plans. Results: Overall, the DMBT tandem generates more conformal dose distributions than conventional tandem for all lateral positional shifts of 0-15 mm (CI=0.91–0.52 and 0.99–0.34, respectively), with an exception at the central position due to the ideal circular dose distribution, generated by the {sup 192}Ir, fitting tightly around the circular target (CI = 0.91 and 0.99, respectively). The DMBT tandem is able to generate dose conformity of CI>0.8 at up to 6-mm positional shift while the conventional tandem violates this past 2-mm shift. Also, the CI ratio (=DMBT/conv.) increases rapidly until about 8 mm and then stabilizes beyond. Conclusion: A substantial enhancement in the dose sculpting capacity has been demonstrated for the novel DMBT tandem applicator. While

Computed Tomography–Planned High-Dose-Rate Brachytherapy for Treating Uterine Cervical Cancer

Energy Technology Data Exchange (ETDEWEB)

Zolciak-Siwinska, Agnieszka, E-mail: agnieszka.zolciak@wp.pl [Department of Brachytherapy, The Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw (Poland); Gruszczynska, Ewelina; Bijok, Michal [Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw (Poland); Jonska-Gmyrek, Joanna [Department of Teleradiotherapy, The Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw (Poland); Dabkowski, Mateusz [Department of Brachytherapy, The Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw (Poland); Staniaszek, Jagna [Department of Teleradiotherapy, The Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw (Poland); Michalski, Wojciech [Department of Clinical Trials and Biostatistics, The Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw (Poland); Kowalczyk, Adam; Milanowska, Katarzyna [Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw (Poland)

2016-09-01

Purpose: To evaluate the long-term results of computed tomography (CT)–planned high-dose-rate (HDR) brachytherapy (BT) for treating cervical cancer patients. Methods and Materials: CT-planned HDR BT was performed according to the adapted Group European de Curietherapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) recommendations in 216 consecutive patients with locally advanced cervical cancer, International Federation of Gynecology and Obstetrics (FIGO) stage IB to IVA, who were treated with conformal external beam radiation therapy and concomitant chemotherapy. We analyzed outcomes and late side effects evaluated according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer and Subjective, Objective, Management, Analysis evaluation scoring system and compared them with the results from a historical group. Results: The median age was 56 years (range, 32-83 years). The median follow-up time for living patients was 52 months (range 37-63 months). The 5-year cumulative incidence function for the local recurrence rate for patients with FIGO II and III was 5.5% and 20%, respectively (P=.001). The 5-year rates of overall survival (OS) and disease-free survival (DFS) were 66.4% and 58.5%, respectively. The relative risk of failure for OS and DFS for FIGO III in relation to FIGO II was 2.24 (P=.003) and 2.6 (P=.000) and for lymph node enlargement was 2.3 (P=.002) and 2 (P=.006), respectively. In 2 patients, rectovaginal fistula occurred, and in 1 patient, vesicovaginal fistula occurred without local progression. Comparison of late adverse effects in patients treated according to the GEC-ESTRO recommendations and in the historical group revealed a reduction in fistula formation of 59% and also a reduction in rectal grade 3 to 4 late toxicity of >59%. Conclusions: This is the largest report with mature data of CT-planned BT HDR for the treatment of cervical cancer with good local control and

Urethra-Sparing, Intraoperative, Real-Time Planned, Permanent-Seed Prostate Brachytherapy: Toxicity Analysis

Energy Technology Data Exchange (ETDEWEB)

Zilli, Thomas [Department of Radiation Oncology, Centre hospitalier de l' Universite de Montreal-Hopital Notre-Dame, Montreal, QC (Canada); Taussky, Daniel, E-mail: daniel.taussky.chum@ssss.gouv.qc.ca [Department of Radiation Oncology, Centre hospitalier de l' Universite de Montreal-Hopital Notre-Dame, Montreal, QC (Canada); Donath, David; Le, Hoa Phong; Larouche, Renee-Xaviere; Beliveau-Nadeau, Dominique; Hervieux, Yannick; Delouya, Guila [Department of Radiation Oncology, Centre hospitalier de l' Universite de Montreal-Hopital Notre-Dame, Montreal, QC (Canada)

2011-11-15

Purpose: To report the toxicity outcome in patients with localized prostate cancer undergoing {sup 125}I permanent-seed brachytherapy (BT) according to a urethra-sparing, intraoperative (IO), real-time planned conformal technique. Methods and Materials: Data were analyzed on 250 patients treated consecutively for low- or intermediate-risk prostate cancer between 2005 and 2009. The planned goal was urethral V{sub 150} = 0. Acute and late genitourinary (GU), gastrointestinal (GI), and erectile toxicities were scored with the International Prostate Symptom Score (IPSS) questionnaire and Common Terminology Criteria for Adverse Events (version 3.0). Median follow-up time for patients with at least 2 years of follow-up (n = 130) was 34.4 months (range, 24-56.9 months). Results: Mean IO urethra V{sub 150} was 0.018% {+-} 0.08%. Mean prostate D{sub 90} and V{sub 100} on day-30 computed tomography scan were 158.0 {+-} 27.0 Gy and 92.1% {+-} 7.2%, respectively. Mean IPSS peak was 9.5 {+-} 6.3 1 month after BT (mean difference from baseline IPSS, 5.3). No acute GI toxicity was observed in 86.8% of patients. The 3-year probability of Grade {>=}2 late GU toxicity-free survival was 77.4% {+-} 4.0%, with Grade 3 late GU toxicity encountered in only 3 patients. Three-year Grade 1 late GI toxicity-free survival was 86.1% {+-} 3.2%. No patient presented Grade {>=}2 late GI toxicity. Of patients with normal sexual status at baseline, 20.7% manifested Grade {>=}2 erectile dysfunction after BT. On multivariate analysis, elevated baseline IPSS (p = 0.016) and high-activity sources (median 0.61 mCi) (p = 0.033) predicted increased Grade {>=}2 late GU toxicity. Conclusions: Urethra-sparing IO BT results in low acute and late GU toxicity compared with the literature. High seed activity and elevated IPSS at baseline increased long-term GU toxicity.

Comparison of Dose When Prescribed to Point A and Point H for Brachytherapy in Cervical Cancer

Energy Technology Data Exchange (ETDEWEB)

Gang, Ji Hyeong; Gim, Il Hwan; Hwang, Seon Boong; Kim, Woong; Im, Hyeong Seo; Gang, Jin Mook; Gim, Gi Hwan; Lee, Ah Ram [Dept. of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seou (Korea, Republic of)

2012-09-15

The purpose of this study is to compare plans prescribed to point A with these prescribed to point H recommended by ABS (American Brachytherapy Society) in high dose rate intracavitary brachytherapy for cervical carcinoma. This study selected 103 patients who received HDR (High Dose Rate) brachytherapy using tandem and ovoids from March 2010 to January 2012. Point A, bladder point, and rectal point conform with Manchester System. Point H conforms with ABS recommendation. Also Sigmoid colon point, and vagina point were established arbitrarily. We examined distance between point A and point H. The percent dose at point A was calculated when 100% dose was prescribed to point H. Additionally, the percent dose at each reference points when dose is prescribed to point H and point A were calculated. The relative dose at point A was lower when point H was located inferior to point A. The relative doses at bladder, rectal, sigmoid colon, and vagina points were higher when point H was located superior to point A, and lower when point H was located inferior to point A. This study found out that as point H got located much superior to point A, the absorbed dose of surrounding normal organs became higher, and as point H got located much inferior to point A, the absorbed dose of surrounding normal organs became lower. This differences dose not seem to affect the treatment. However, we suggest this new point is worth being considered for the treatment of HDR if dose distribution and absorbed dose at normal organs have large differences between prescribed to point A and H.

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.

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.

Evaluation of homogeneity and dose conformity in IMRT planning in prostate radiotherapy

International Nuclear Information System (INIS)

Lopes, Juliane S.; Leidens, Matheus; Estacio, Daniela R.; Razera, Ricardo A.Z.; Streck, Elaine E.; Silva, Ana M.M. da

2015-01-01

The goal of this study was to evaluate the dose distribution homogeneity and conformity of radiation therapy plans of prostate cancer using IMRT. Data from 34 treatment plans of Hospital Sao Lucas of PUCRS, where those plans were executed, were retrospectively analyzed. All of them were done with 6MV X-rays from a linear accelerator CLINAC IX, and the prescription doses varied between 60 and 74 Gy. Analyses showing the homogeneity and conformity indices for the dose distribution of those plans were made. During these analyses, some comparisons with the traditional radiation therapy planning technic, the 3D-CRT, were discussed. The results showed that there is no correlation between the prescribed dose and the homogeneity and conformity indices, indicating that IMRT works very well even for higher doses. Furthermore, a comparison between the results obtained and the recommendations of ICRU 83 was carried out. It has also been observed that the indices were really close to the ideal values. 82.4% of the cases showed a difference below 5% of the ideal value for the index of conformity, and 88.2% showed a difference below 10% for the homogeneity index. Concluding, it is possible to confirm the quality of the analyzed radiation therapy plans of prostate cancer using IMRT. (author)

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

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

2014-05-15

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

Methods for prostate stabilization during transperineal LDR brachytherapy.

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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

Design and implementation of a film dosimetry audit tool for comparison of planned and delivered dose distributions in high dose rate (HDR) brachytherapy

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Palmer, Antony L.; Lee, Chris; Ratcliffe, Ailsa J.; Bradley, David; Nisbet, Andrew

2013-10-01

A novel phantom is presented for ‘full system’ dosimetric audit comparing planned and delivered dose distributions in HDR gynaecological brachytherapy, using clinical treatment applicators. The brachytherapy applicator dosimetry test object consists of a near full-scatter water tank with applicator and film supports constructed of Solid Water, accommodating any typical cervix applicator. Film dosimeters are precisely held in four orthogonal planes bisecting the intrauterine tube, sampling dose distributions in the high risk clinical target volume, points A and B, bladder, rectum and sigmoid. The applicator position is fixed prior to CT scanning and through treatment planning and irradiation. The CT data is acquired with the applicator in a near clinical orientation to include applicator reconstruction in the system test. Gamma analysis is used to compare treatment planning system exported RTDose grid with measured multi-channel film dose maps. Results from two pilot audits are presented, using Ir-192 and Co-60 HDR sources, with a mean gamma passing rate of 98.6% using criteria of 3% local normalization and 3 mm distance to agreement (DTA). The mean DTA between prescribed dose and measured film dose at point A was 1.2 mm. The phantom was funded by IPEM and will be used for a UK national brachytherapy dosimetry audit.

Design and implementation of a film dosimetry audit tool for comparison of planned and delivered dose distributions in high dose rate (HDR) brachytherapy

International Nuclear Information System (INIS)

Palmer, Antony L; Bradley, David; Nisbet, Andrew; Lee, Chris; Ratcliffe, Ailsa J

2013-01-01

A novel phantom is presented for ‘full system’ dosimetric audit comparing planned and delivered dose distributions in HDR gynaecological brachytherapy, using clinical treatment applicators. The brachytherapy applicator dosimetry test object consists of a near full-scatter water tank with applicator and film supports constructed of Solid Water, accommodating any typical cervix applicator. Film dosimeters are precisely held in four orthogonal planes bisecting the intrauterine tube, sampling dose distributions in the high risk clinical target volume, points A and B, bladder, rectum and sigmoid. The applicator position is fixed prior to CT scanning and through treatment planning and irradiation. The CT data is acquired with the applicator in a near clinical orientation to include applicator reconstruction in the system test. Gamma analysis is used to compare treatment planning system exported RTDose grid with measured multi-channel film dose maps. Results from two pilot audits are presented, using Ir-192 and Co-60 HDR sources, with a mean gamma passing rate of 98.6% using criteria of 3% local normalization and 3 mm distance to agreement (DTA). The mean DTA between prescribed dose and measured film dose at point A was 1.2 mm. The phantom was funded by IPEM and will be used for a UK national brachytherapy dosimetry audit. (paper)

[Technique of intraoperative planning in prostatic brachytherapy with permanent implants of 125I or 103Pd].

Science.gov (United States)

Prada Gómez, Pedro José; Juan Rijo, Germán; Hevia Suarez, Miguel; Abascal García, José María; Abascal García, Ramón

2002-12-01

Prostatic brachytherapy with permanent 125I or 123Pd seeds implantation is a therapeutic option for organ-confined prostate cancer. We analyze the technique based on previous planning, our current intraoperative planning procedure and the reasons that moved us to introduce this change. Changes in prostate volume and spatial localization observed between previous planning and intraoperative images, and possible difficulties for seed implantation due to pubic arch interference are some of the reasons that induce us to change technique. Before the operation, we calculate the prostatic volume by transrectal ultrasound; with this information we determine the total implant activity following Wu's nomogram, and per-seed activity; therefore, it is an individual process for each patient. We perform a peripheral implant, placing 75-80% of the seeds within the peripheral prostatic zone, generally through 12-15 needles, the rest of the seeds are placed in the central prostatic zone using a maximum of 3-4 needles in high volume prostates. The day of intervention, after positioning and catheter insertion, volumetry is re-checked. Ultrasound images (from base to apex every 5 mm) are transferred to the planner were a suitable seed distribution is determined. Implantation is then performed placing all needles unloaded, and then intraoperative post-planning to allow us to check implant precision is performed after cistoscopically check that there is no urethral or bladder penetration by any needle. We finish with the insertion of seeds into the prostate. Total time for the procedure is around 90 minutes. Intraoperative planning is an additional step for the treatment of prostate cancer with permanent seeds brachytherapy, which avoids the disadvantages of previous planning and improves tumor inclusion in the ideal irradiation dose area, which will translate into better local disease control.

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

Technical aspects of the integration of three-dimensional treatment planning dose parameters (GEC-ESTRO Working Group) into pre-implant planning for LDR gynecological interstitial brachytherapy.

Science.gov (United States)

Chi, A; Gao, M; Nguyen, N P; Albuquerque, K

2009-06-01

This study investigates the technical feasibility of pre-implant image-based treatment planning for LDR GYN interstitial brachytherapy(IB) based on the GEC-ESTRO guidelines. Initially, a virtual plan is generated based on the prescription dose and GEC-ESTRO defined OAR dose constraints with a pre-implant CT. After the actual implant, a regular diagnostic CT was obtained and fused with our pre-implant scan/initial treatment plan in our planning software. The Flexi-needle position changes, and treatment plan modifications were made if needed. Dose values were normalized to equivalent doses in 2 Gy fractions (LQED 2 Gy) derived from the linear-quadratic model with alpha/beta of 3 for late responding tissues and alpha/beta of 10 for early responding tissues. D(90) to the CTV, which was gross tumor (GTV) at the time of brachytherapy with a margin to count for microscopic disease, was 84.7 +/- 4.9% of the prescribed dose. The OAR doses were evaluated by D(2cc) (EBRT+IB). Mean D(2cc) values (LQED(2Gy)) for the rectum, bladder, sigmoid, and small bowel were the following: 63.7 +/- 8.4 Gy, 61.2 +/- 6.9 Gy, 48.0 +/- 3.5 Gy, and 49.9 +/- 4.2 Gy. This study confirms the feasibility of applying the GEC-ESTRO recommended dose parameters in pre-implant CT-based treatment planning in GYN IB. In the process, this pre-implant technique also demonstrates a good approximation of the target volume dose coverage, and doses to the OARs.

Developing A Directional High-Dose Rate (d-HDR) Brachytherapy Source

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Heredia, Athena Yvonne

Conventional sources used in brachytherapy provide nearly isotropic or radially symmetric dose distributions. Optimizations of dose distributions have been limited to varied dwell times at specified locations within a given treatment volume, or manipulations in source position for seed implantation techniques. In years past, intensity modulated brachytherapy (IMBT) has been used to reduce the amount of radiation to surrounding sensitive structures in select intracavitary cases by adding space or partial shields. Previous work done by Lin et al., at the University of Wisconsin-Madison, has shown potential improvements in conformality for brachytherapy treatments using a directionally shielded low dose rate (LDR) source for treatments in breast and prostate. Directional brachytherapy sources irradiate approximately half of the radial angles around the source, and adequately shield a quarter of the radial angles on the opposite side, with sharp gradient zones between the treated half and shielded quarter. With internally shielded sources, the radiation can be preferentially emitted in such a way as to reduce toxicities in surrounding critical organs. The objective of this work is to present findings obtained in the development of a new directional high dose rate (d-HDR) source. To this goal, 103Pd (Z = 46) is reintroduced as a potential radionuclide for use in HDR brachytherapy. 103Pd has a low average photon energy (21 keV) and relatively short half -life (17 days), which is why it has historically been used in low dose rate applications and implantation techniques. Pd-103 has a carrier-free specific activity of 75000 Ci/g. Using cyclotron produced 103Pd, near carrier-free specific activities can be achieved, providing suitability for high dose rate applications. The evolution of the d-HDR source using Monte Carlo simulations is presented, along with dosimetric parameters used to fully characterize the source. In addition, a discussion on how to obtain elemental

A 3D computer graphics approach to brachytherapy planning.

Science.gov (United States)

Weichert, Frank; Wawro, Martin; Wilke, Carsten

2004-06-01

Intravascular brachytherapy (IVB) can significantly reduce the risk of restenosis after interventional treatment of stenotic arteries, if planned and applied correctly. In order to facilitate computer-based IVB planning, a three-dimensional reconstruction of the stenotic artery based on intravascular ultrasound (IVUS) sequences is desirable. For this purpose, the frames of the IVUS sequence are properly aligned in space, possible gaps inbetween the IVUS frames are filled by interpolation with radial basis functions known from scattered data interpolation. The alignment procedure uses additional information which is obtained from biplane X-ray angiography performed simultaneously during the capturing of the IVUS sequence. After IVUS images and biplane angiography data are acquired from the patient, the vessel-wall borders and the IVUS catheter are detected by an active contour algorithm. Next, the twist (relative orientation) between adjacent IVUS frames is determined by a sequential triangulation method. The absolute orientation of each frame is established by a stochastic analysis based on anatomical landmarks. Finally, the reconstructed 3D vessel model is visualized by methods of combined volume and polygon rendering. The reconstruction is then used for the computation of the radiation-distribution within the tissue, emitted from a beta-radiation source. All these steps are performed during the percutaneous intervention.

78 FR 78310 - Approval and Promulgation of Implementation Plans; North Carolina; Transportation Conformity...

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2013-12-26

...] Approval and Promulgation of Implementation Plans; North Carolina; Transportation Conformity Memorandum of... Resources. This submission adopts a memorandum of agreement establishing transportation conformity criteria...-related control measures and mitigation measures. This proposed action streamlines the conformity process...

78 FR 68005 - Approval and Promulgation of Implementation Plans; Mississippi; Transportation Conformity SIP...

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2013-11-13

...] Approval and Promulgation of Implementation Plans; Mississippi; Transportation Conformity SIP--Memorandum... transportation conformity criteria and procedures related to interagency consultation and enforceability of... conformity process to allow direct consultation among agencies at the Federal, state and local levels. This...

A method of quality audit for treatment planning system for intracavitary HDR brachytherapy

International Nuclear Information System (INIS)

Sharma, S.D.; Vandana, S.; Philomina, A.; Kannan, S.; Rituraj, U.

2007-01-01

High dose rate brachytherapy is a multipurpose modality. Quality audit (QAu) is an independent examination and evaluation of quality assurance activities and results of an institution. Both clinical and physical aspects of patient treatments must be subjected to careful control and planning to achieve a high degree of accuracy in radiation therapy treatments. Comprehensive quality assurance (QA) programmes should be established to cover all steps from dose prescription to dose delivery. These programmes should include detailed internal checks performed by the radiotherapy centres and external audits made by independent bodies. A systematic and independent examination and evaluation to determine whether quality activities and results comply with planned arrangements and whether the arrangements are implemented effectively and are suitable to achieve objectives is called quality audit. One purpose of a quality audit (QAu) is to evaluate the need for improvement or corrective action

A Monte Carlo dosimetry study using Henschke applicator for cervical brachytherapy

International Nuclear Information System (INIS)

Yu, Pei-Chieh; Chao, Tsi-Chian; Lee, Chung-Chi; Wu, Ching-Jung; Tung, Chuan-Jong

2010-01-01

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

On-line conformal HDR dose escalation trial in prostate cancer

International Nuclear Information System (INIS)

Martinez, Alvaro; Stromberg, Jannifer; Edmundson, Gregory; Gustafson, Gary; Vicini, Frank; Brabbins, Donald

1996-01-01

Purpose: To improve treatment results on prostatic adenocarcinoma, we began the first prospective Phase I/II dose-escalating clinical trial of conformal brachytherapy (CB) and concurrent external beam irradiation. Methods and Materials: Fifty-four patients with T2b-T3c prostatic adenocarcinoma received 172 transperineal conformal high-dose rate (HDR) boost implants. All patients received concomitant external beam pelvic irradiation. Dose escalation of the three HDR fractions were: 5.5 Gy (18 patients), 6 Gy (15 patients), and 6.5 Gy (21 patients). The urethra, anterior rectal wall, and prostate boundaries were identified individually and outlined at 5 mm intervals from the base to the apex of the gland. The CB using real-time ultrasound guidance with interactive online isodose distributions was performed on an outpatient basis. As needles were placed into the prostate, corrections for prostate displacement were recorded and the isodose distributions were recalculated to represent the new relationship between the needles, prostate, and normal structures. Results: Craniocaudal motion of the gland ranged from 0.5-2.0 cm (mean=1.0 cm), whereas lateral displacement was 0.1-0.4 cm. With the interactive online planning system, organ motion was immediately detected, accounted for, and corrected prior to each HDR treatment. The rectal dose has ranged from 45 to 87%, and the urethral dose from 97 to 112% of the prostate dose. Negative prostatic biopsies at 18 months were seen in (30(32)) patients. Biochemical (PSA <1.5 ng/ml) control at 36 months is is 89%. It is significant that operator dependence has been completely removed because the interactive online planning system uniformly guides the physicians. Conclusions: With ultrasound guidance and the interactive online dosimetry system, organ motion is insignificant because it can be corrected during the procedure. Common pitfalls of brachytherapy, including operator dependence and difficulty with reproducibility, have been

Comparison of absorbed dose in the cervix carcinoma therapy by brachytherapy of high dose rate using the conventional planning and Monte Carlo simulation

International Nuclear Information System (INIS)

Silva, Aneli Oliveira da

2010-01-01

This study aims to compare the doses received for patients submitted to brachytherapy High Dose Rate (HDR) brachytherapy, a method of treatment of the cervix carcinoma, performed in the planning system PLATO BPS with the doses obtained by Monte Carlo simulation using the radiation transport code MCNP 5 and one female anthropomorphic phantom based on voxel, the FAX. The implementation of HDR brachytherapy treatment for the cervix carcinoma consists of the insertion of an intrauterine probe and an intravaginal probe (ring or ovoid) and then two radiographs are obtained, anteroposterior (AP) and lateral (LAT) to confirm the position of the applicators in the patient and to allow the treatment planning and the determination of the absorbed dose at points of interest: rectum, bladder, sigmoid and point A, which corresponds anatomically to the crossings of the uterine arteries with ureters The absorbed doses obtained with the code MCNP 5, with the exception of the absorbed dose in the rectum and sigmoid for the simulation considering a point source of 192 Ir, are lower than the absorbed doses from PLATO BPS calculations because the MCNP 5 considers the chemical compositions and densities of FAX body, not considering the medium as water. When considering the Monte Carlo simulation for a source with dimensions equal to that used in the brachytherapy irradiator used in this study, the values of calculated absorbed dose to the bladder, to the rectum, to the right point A and to the left point A were respectively lower than those determined by the treatment planning system in 33.29, 5.01, 22.93 and 19.04%. These values are almost all larger than the maximum acceptable deviation between patient planned and administered doses (5 %). With regard to the rectum and bladder, which are organs that must be protected, the present results are in favor of the radiological protection of patients. The point A, that is on the isodose of 100%, used to tumor treatment, the results indicate

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

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

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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.

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

Directory of Open Access Journals (Sweden)

Shilpa Sachdeva, MD

2017-03-01

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

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

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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.

SU-F-T-29: The Important of Each Fraction Image-Guided Planning for Postoperative HDR-Brachytherapy in Endometrial Carcinoma

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Piriyasang, D; Pattaranutaporn, P; Manokhoon, K [Ramathibodi Hospital, Rachatewi, Bangkok (Thailand)

2016-06-15

Purpose: Cylindrical applicators are often used for postoperative HDRbrachytherapy in endometrial carcinoma. It has been considered that dosimetric variation between fractions for this treatment is minimal and might not be necessary to perform treatment planning for every fractions. At our institute, it is traditional to perform treatment planning with CT simulation on the first fraction and uses this plan for the rest of treatment. This study was aim to evaluate the errors of critical structure doses between the fractions when simulation and planning were done for first fraction only. Methods: Treatment plans of 10 endometrial carcinoma patients who received postoperative HDR-brachytherapy and underwent CT-simulation for every HDR-fractions at our department were retrospectively reviewed. All of these patients were treated with cylindrical applicator and prescribed dose 15Gy in 3 fractions to 0.5cm from vaginal surface. The treatment plan from the first fraction was used to simulate in second and third CT-simulation. Radiation dose for critical structures in term of Dose-to-2cc (D2cc) were evaluated and compared between planning CT. Results: The D2cc for bladder and rectum were evaluated. For bladder, the mean error of D2cc estimation for second and third fractions was 7.6% (0.1–20.1%, SD=5.7). And the mean error for D2cc of rectum was 8.5% (0.1–29.4%, SD=8.5). Conclusion: The critical structure doses could be significant difference between fractions which may affects treatment outcomes or toxicities. From our data, image-guided brachytherapy at least with CT-Simulation should be done for every treatment fractions.

75 FR 50730 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Transportation Conformity...

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2010-08-17

... Promulgation of Air Quality Implementation Plans; Indiana; Transportation Conformity Consultation Requirement... consists of transportation conformity criteria and procedures related to interagency consultation and... meet a requirement of the Clean Air Act and Transportation Conformity regulations. DATES: Comments must...

Dose calculation and isodose curves determination in brachytherapy

International Nuclear Information System (INIS)

Maranhao, Frederico B.; Lima, Fernando R.A.; Khoury, Helen J.

2000-01-01

Brachytherapy is a form of cancer treatment in which small radioactive sources are placed inside of, or close to small tumors, in order to cause tissue necrosis and, consequently, to interrupt the tumor growth process. A very important aspect to the planning of this therapy is the calculation of dose distributions in the tumor and nearby tissues, to avoid the unnecessary irradiation of healthy tissue. The objective of this work is to develop a computer program that will permit treatment planning for brachytherapy at low dose rates, minimizing the possible errors introduced when such calculations are done manually. Results obtained showed good agreement with those from programs such as BRA, which is widely used in medical practice. (author)

77 FR 59100 - Approval and Promulgation of Implementation Plans; Alabama: General and Transportation Conformity...

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2012-09-26

... Promulgation of Implementation Plans; Alabama: General and Transportation Conformity & New Source Review... (SMC) Rule. The SIP revision also changes the State's general and transportation conformity regulations... federal general and transportation conformity regulations into the SIP. Alabama's May 2, 2011, SIP...

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

Relocation of a nucletron microselectron-HDR brachytherapy system

Energy Technology Data Exchange (ETDEWEB)

Bartrum, T; Tran, T; Freeman, N; Morales, J [St Vincents Hospital, Darlinghurst, NSW (Australia)

2004-12-15

Full text: For a period of four weeks, our clinical Nucletron microSelectron high dose rate (HDR) brachytherapy system was pulled out of clinical use and relocated to a new building. During this period decommission tests, de-wiring of the treatment unit and its associated safety system (such as radiation detector, emergency off circuits and door interlocks), transportation of all equipment, re-wiring of this equipment in the new location and recommission tests were carried out. The decommission and recommission test program was designed upon consultation with the manufacturer's (Nucletron) acceptance test procedures and work carried out by others. The ACPSEM tolerances for remote afterloaders was used as a guideline. In addition to mandatory dosimetry, positional, workstation database and safety tests, two Australian Standard compliance tests were carried out. The compliance tests involved one for remote afterloaders and another for treatment room design. This testing program was designed and implemented with the aim of ensuring ongoing safe delivery of brachytherapy doses to the patient. The testing program consisted of two parts. The first involved a series of decommissioning tests that consisted of dosimetry tests such as source and check cable positional accuracy and source calibration tests. In addition to these tests an inventory of standard plans, patient records and system configuration information was catalogued. The second part involved a series of recommission tests and involved carrying out dosimetry tests on the brachytherapy system (positional accuracy and calibration tests), simulating common treatment scenarios (prostate, cervical, vaginal and bile duct) and checking standard plans; patient records and system configuration had remained unchanged. During this period, other tests were carried out. These included Nucletron acceptance and preventative maintenance tests, Australian Standards compliance testing and integrity of network transfer of

Relocation of a nucletron microselectron-HDR brachytherapy system

International Nuclear Information System (INIS)

Bartrum, T.; Tran, T.; Freeman, N.; Morales, J.

2004-01-01

Full text: For a period of four weeks, our clinical Nucletron microSelectron high dose rate (HDR) brachytherapy system was pulled out of clinical use and relocated to a new building. During this period decommission tests, de-wiring of the treatment unit and its associated safety system (such as radiation detector, emergency off circuits and door interlocks), transportation of all equipment, re-wiring of this equipment in the new location and recommission tests were carried out. The decommission and recommission test program was designed upon consultation with the manufacturer's (Nucletron) acceptance test procedures and work carried out by others. The ACPSEM tolerances for remote afterloaders was used as a guideline. In addition to mandatory dosimetry, positional, workstation database and safety tests, two Australian Standard compliance tests were carried out. The compliance tests involved one for remote afterloaders and another for treatment room design. This testing program was designed and implemented with the aim of ensuring ongoing safe delivery of brachytherapy doses to the patient. The testing program consisted of two parts. The first involved a series of decommissioning tests that consisted of dosimetry tests such as source and check cable positional accuracy and source calibration tests. In addition to these tests an inventory of standard plans, patient records and system configuration information was catalogued. The second part involved a series of recommission tests and involved carrying out dosimetry tests on the brachytherapy system (positional accuracy and calibration tests), simulating common treatment scenarios (prostate, cervical, vaginal and bile duct) and checking standard plans; patient records and system configuration had remained unchanged. During this period, other tests were carried out. These included Nucletron acceptance and preventative maintenance tests, Australian Standards compliance testing and integrity of network transfer of

76 FR 77150 - Approval and Promulgation of Air Quality Implementation Plans; Virginia; General Conformity...

Science.gov (United States)

2011-12-12

... Promulgation of Air Quality Implementation Plans; Virginia; General Conformity Requirements for Federal... incorporate revisions to Federal general conformity requirements promulgated in July of 2006 and in April of 2010. EPA is approving this Virginia SIP revision to update its state general conformity requirements...

Determining the distribution of the absorbed dose for a body exposed to Cs-137 using the Monte Carlo method and application in a brachytherapy treatment planning

International Nuclear Information System (INIS)

Randriantsizafy, R.D.

2014-01-01

Brachytherapy is a means of precise and effective cancer treatment. This is due to the nearby sources of ionizing radiation. The precision and efficiency requires a good dosimetry and a good knowledge of the dose distribution in the patient. The aim is to give the right dose of ionizing radiation to destroy the tumor while reducing the dose to sensitive organs such as the bladder , liver, .... The Monte Carlo is a recognized model method for the distribution of radiation in the material. It is used in this work to determine the doses to organs during treatment planning for Cesium -137 brachytherapy. The programming language used is Python . Library outcome of this work is used in a web application BrachyPy, we designed to replace the manual processing in the Cs-137 brachytherapy planning. Model validation is done by comparing the isodose curves of the model with the isodose curves abacus NUCLETRON and the last report of the American Association of Medical Physics (AAPM) on the amendment to the algorithm TG43. [fr

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.

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

Verification of the calculation program for brachytherapy planning system of high dose rate (PLATO)

International Nuclear Information System (INIS)

Almansa, J.; Alaman, C.; Perez-Alija, J.; Herrero, C.; Real, R. del; Ososrio, J. L.

2011-01-01

In our treatments are performed brachytherapy high dose rate since 2007. The procedures performed include gynecological intracavitary treatment and interstitial. The treatments are performed with a source of Ir-192 activity between 5 and 10 Ci such that small variations in treatment times can cause damage to the patient. In addition the Royal Decree 1566/1998 on Quality Criteria in radiotherapy establishes the need to verify the monitor units or treatment time in radiotherapy and brachytherapy. All this justifies the existence of a redundant system for brachytherapy dose calculation that can reveal any abnormality is present.

76 FR 77182 - Approval and Promulgation of Air Quality Implementation Plans; Virginia; General Conformity...

Science.gov (United States)

2011-12-12

... Promulgation of Air Quality Implementation Plans; Virginia; General Conformity Requirements for Federal... purpose of incorporating Federal general conformity requirements revisions promulgated in July of 2006 and... conformity SIP revision and if that provision may be severed from the remainder of the rule, EPA may adopt as...

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

Experimental dosimetry in conformal breast teletherapy compared with the planning system

International Nuclear Information System (INIS)

Nogueira, Luciana Batista; Silva, Hugo Leonardo Lemos; Passos Ribeiro de Campos, Tarcísio

2015-01-01

The objective of this study was to compare and analyse the absorbed dose profiles from the conformal radiotherapy planning and experimental dosimetry taken in a breast anthropomorphic and anthropometric phantom. Conformal radiotherapy planning was elaborated in the Treatment Planning System (TPS). EBT2 Gafchromic radiochromic films were applied as dosimeters, positioned internally and superficially in the breast phantom. The standard radiation protocol was applied in the breast phantom. The films were digitalised, and their responses were analysed in RGB. The optical densities were processed, reproducing the spatial dose distribution. - Highlights: • Distributions of absorbed doses were generated by the TPS and measured by radiochromic films. • The breast phantom simulated a human breast in position for treatment. • A large portion of the glandular tissue absorbed doses that were equivalent to the radiotherapy planning. • There were regions of hot spots and small areas of under dosage in deeper areas at the lung interface

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

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. 

SU-G-TeP1-01: A Simulation Study to Investigate Maximum Allowable Deformations of Implant Geometry Before Plan Objectives Are Violated in Prostate HDR Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Babier, A [Department of Physics, Engineering Physics and Astronomy, Queens University, Kingston, Ontario (Canada); Joshi, C [Department of Physics, Engineering Physics and Astronomy, Queens University, Kingston, Ontario (Canada); Cancer Center of Southeastern Ontario, Kingston General Hospital, Kingston, Ontario (Canada)

2016-06-15

Purpose: In prostate HDR brachytherapy dose distributions are highly sensitive to changes in prostate volume and catheter displacements. We investigate the maximum deformations in implant geometry before planning objectives are violated. Methods: A typical prostate Ir-192 HDR brachytherapy reference plan was calculated on the Oncentra planning system, which used CT images from a tissue equivalent prostate phantom (CIRS Model 053S) embedded inside a pelvis wax phantom. The prostate was deformed and catheters were displaced in simulations using a code written in MATLAB. For each deformation dose distributions were calculated, based on TG43 methods, using the MATLAB code. The calculations were validated through comparison with Oncentra calculations for the reference plan, and agreed within 0.12%SD and 0.3%SD for dose and volume, respectively. Isotropic prostate volume deformations of up to +34% to −27% relative to its original volume, and longitudinal catheter displacements of 7.5 mm in superior and inferior directions were simulated. Planning objectives were based on American Brachytherapy Society guidelines for prostate and urethra volumes. A plan violated the planning objectives when less than 90% of the prostate volume received the prescribed dose or higher (V{sub 100}), or the urethral volume receiving 125% of prescribed dose or higher was more than 1 cc (U{sub 125}). Lastly, the dose homogeneity index (DHI=1-V{sub 150}/V{sub 100}) was evaluated; a plan was considered sub-optimal when the DHI fell below 0.62. Results and Conclusion: Planning objectives were violated when the prostate expanded by 10.7±0.5% or contracted by 11.0±0.2%; objectives were also violated when catheters were displaced by 4.15±0.15 mm and 3.70±0.15 mm in the superior and inferior directions, respectively. The DHI changes did not affect the plan optimality, except in the case of prostate compression. In general, catheter displacements have a significantly larger impact on plan

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

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)

Implant strategies for endocervical and interstitial ultrasound hyperthermia adjunct to HDR brachytherapy for the treatment of cervical cancer

International Nuclear Information System (INIS)

Wootton, Jeffery H; Prakash, Punit; Hsu, I-Chow Joe; Diederich, Chris J

2011-01-01

Catheter-based ultrasound devices provide a method to deliver 3D conformable heating integrated with HDR brachytherapy delivery. Theoretical characterization of heating patterns was performed to identify implant strategies for these devices which can best be used to apply hyperthermia to cervical cancer. A constrained optimization-based hyperthermia treatment planning platform was used for the analysis. The proportion of tissue ≥41 deg. C in a hyperthermia treatment volume was maximized with constraints T max ≤ 47 deg. C, T rectum ≤ 41.5 deg. C, and T bladder ≤ 42.5 deg. C. Hyperthermia treatment was modeled for generalized implant configurations and complex configurations from a database of patients (n = 14) treated with HDR brachytherapy. Various combinations of endocervical (360 0 or 2 x 180 0 output; 6 mm OD) and interstitial (180 0 , 270 0 , or 360 0 output; 2.4 mm OD) applicators within catheter locations from brachytherapy implants were modeled, with perfusion constant (1 or 3 kg m -3 s -1 ) or varying with location or temperature. Device positioning, sectoring, active length and aiming were empirically optimized to maximize thermal coverage. Conformable heating of appreciable volumes (>200 cm 3 ) is possible using multiple sectored interstitial and endocervical ultrasound devices. The endocervical device can heat >41 deg. C to 4.6 cm diameter compared to 3.6 cm for the interstitial. Sectored applicators afford tight control of heating that is robust to perfusion changes in most regularly spaced configurations. T 90 in example patient cases was 40.5-42.7 deg. C (1.9-39.6 EM 43deg.C ) at 1 kg m -3 s -1 with 10/14 patients ≥41 deg. C. Guidelines are presented for positioning of implant catheters during the initial surgery, selection of ultrasound applicator configurations, and tailored power schemes for achieving T 90 ≥ 41 deg. C in clinically practical implant configurations. Catheter-based ultrasound devices, when adhering to the guidelines, show

Dose modeling of noninvasive image-guided breast brachytherapy in comparison to electron beam boost and three-dimensional conformal accelerated partial breast irradiation.

Science.gov (United States)

Sioshansi, Shirin; Rivard, Mark J; Hiatt, Jessica R; Hurley, Amanda A; Lee, Yoojin; Wazer, David E

2011-06-01

To perform dose modeling of a noninvasive image-guided breast brachytherapy (NIIGBB) for comparison to electrons and 3DCRT. The novel technology used in this study is a mammography-based, noninvasive breast brachytherapy system whereby the treatment applicators are centered on the planning target volume (PTV) to direct (192)Ir emissions along orthogonal axes. To date, three-dimensional dose modeling of NIIGBB has not been possible because of the limitations of conventional treatment planning systems (TPS) to model variable tissue deformation associated with breast compression. In this study, the TPS was adapted such that the NIIGBB dose distributions were modeled as a virtual point source. This dose calculation technique was applied to CT data from 8 patients imaged with the breast compressed between parallel plates in the cranial-caudal and medial-lateral axes. A dose-volume comparison was performed to simulated electron boost and 3DCRT APBI. The NIIGBB PTV was significantly reduced as compared with both electrons and 3DCRT. Electron boost plans had a lower D(min) than the NIIGBB technique but higher V(100), D(90), and D(50). With regard to PTV coverage for APBI, the only significant differences were minimally higher D(90), D(100), V(80), and V(90), with 3DCRT and D(max) with NIIGBB. The NIIGBB technique, as compared with electrons and 3D-CRT, achieved a lower maximum dose to skin (60% and 10%, respectively) and chest wall/lung (70-90%). NIIGBB achieves a PTV that is smaller than electron beam and 3DCRT techniques. This results in significant normal tissue sparing while maintaining dosimetric benchmarks to the target tissue. Copyright © 2011 Elsevier Inc. All rights reserved.

Evaluation of two intracavitary high-dose-rate brachytherapy devices for irradiating additional and irregularly shaped volumes of breast tissue

International Nuclear Information System (INIS)

Lu, Sharon M.; Scanderbeg, Daniel J.; Barna, Patrick; Yashar, William; Yashar, Catheryn

2012-01-01

The SAVI and Contura breast brachytherapy applicators represent 2 recent advancements in brachytherapy technology that have expanded the number of women eligible for accelerated partial breast irradiation in the treatment of early-stage breast cancer. Early clinical experience with these 2 single-entry, multichannel high-dose-rate brachytherapy devices confirms their ease of use and dosimetric versatility. However, current clinical guidelines for SAVI and Contura brachytherapy may result in a smaller or less optimal volume of treated tissue compared with traditional interstitial brachytherapy. This study evaluates the feasibility of using the SAVI and Contura to irradiate larger and irregularly shaped target volumes, approaching what is treatable with the interstitial technique. To investigate whether additional tissue can be treated, 17 patients treated with the SAVI and 3 with the Contura were selected. For each patient, the planning target volume (PTV) was modified to extend 1.1 cm, 1.3 cm, and 1.5 cm beyond the tumor bed cavity. To evaluate dose conformance to an irregularly shaped target volume, 9 patients treated with the SAVI and 3 with the Contura were selected from the original 20 patients. The following asymmetric PTV margin combinations were assessed for each patient: 1.5/0.3, 1.3/0.3, and 1.1/0.3 cm. For all patients, treatment planning was performed, adopting the National Surgical Adjuvant Breast and Bowel Project guidelines, and dosimetric comparisons were made. The 6–1 and 8–1 SAVI devices can theoretically treat a maximal tissue margin of 1.5 cm and an asymmetric PTV with margins ranging from 0.3 to 1.5 cm. The 10–1 SAVI and Contura can treat a maximal margin of 1.3 cm and 1.1 cm, respectively, and asymmetric PTV with margins ranging from 0.3–1.3 cm. Compared with the Contura, the SAVI demonstrated greater dosimetric flexibility. Risk of developing excessive hot spots increased with the size of the SAVI device. Both the SAVI and Contura

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.

Conformal three dimensional radiotherapy treatment planning in Lund

International Nuclear Information System (INIS)

Knoos, T.; Nilsson, P.; Anders, A.

1995-01-01

The use of conformal therapy is based on 3-dimensional treatment planning as well as on methods and routines for 3-dimensional patient mapping, 3-dimensional virtual simulation and others. The management of patients at the Radiotherapy Department at the University Hospital in Lund (Sweden) is discussed. About 2100 new patients are annually treated with external radiotherapy using seven linear accelerators. Three of the accelerators have dual photon energies and electron treatment facilities. A multi-leaf collimator as well as an electronic portal imaging device are available on one machine. Two simulators and an in-house CT-scanner are used for treatment planning. From 1988 to 1992 Scandiplan (Umplan) was used. Since 1992, the treatment planning system is TMS (HELAX AB, Sweden), which is based on the pencil beam algorithm of Ahnesjo. The calculations use patient modulated accelerator specific energy fluence spectra which are compiled with pencil beams from Monte Carlo generated energy absorption kernels. Heterogeneity corrections are performed with results close to conventional algorithms. Irregular fields, either from standard or individual blocks and from multi-leaf collimators are handled by the treatment planning system. The field shape is determined conveniently using the beam's eye view. The final field shape is exported electronically to either the block cutting machine or the multileaf collimator control computer. All patient fields are checked against the beam's eye view during simulation using manual methods. Treatment verification is performed by portal films and in vivo dosimetry with silicon diodes or TL-dosimetry. Up to now, approximately 4400 patients have received a highly individualized 3-dimensional conformal treatment

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.)

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

Directory of Open Access Journals (Sweden)

Matthew M. Harkenrider

2017-03-01

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

External beam techniques to boost cervical cancer when brachytherapy is not an option—theories and applications

Science.gov (United States)

Kilic, Sarah; Khan, Atif J.; Beriwal, Sushil; Small, William

2017-01-01

The management of locally advanced cervical cancer relies on brachytherapy (BT) as an integral part of the radiotherapy delivery armamentarium. Occasionally, intracavitary BT is neither possible nor available. In these circumstances, post-external beam radiotherapy (EBRT) interstitial brachytherapy and/or hysterectomy may represent viable options that must be adequately executed in a timely manner. However, if these options are not applicable due to patient related or facility related reasons, a formal contingency plan should be in place. Innovative EBRT techniques such as intensity modulated and stereotactic radiotherapy may be considered for patients unable to undergo brachytherapy. Relying on provocative arguments and recent data, this review explores the rationale for and limitations of non-brachytherapy substitutes in that setting aiming to establish a formal process for the optimal execution of this alternative plan. PMID:28603722

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

WE-DE-201-11: Sensitivity and Specificity of Verification Methods Based On Total Reference Air Kerma (TRAK) Or On User Provided Dose Points for Graphically Planned Skin HDR Brachytherapy

International Nuclear Information System (INIS)

Damato, A; Devlin, P; Bhagwat, M; Buzurovic, I; Hansen, J; O’Farrell, D; Cormack, R

2016-01-01

Purpose: To investigate the sensitivity and specificity of a novel verification methodology for image-guided skin HDR brachytherapy plans using a TRAK-based reasonableness test, compared to a typical manual verification methodology. Methods: Two methodologies were used to flag treatment plans necessitating additional review due to a potential discrepancy of 3 mm between planned dose and clinical target in the skin. Manual verification was used to calculate the discrepancy between the average dose to points positioned at time of planning representative of the prescribed depth and the expected prescription dose. Automatic verification was used to calculate the discrepancy between TRAK of the clinical plan and its expected value, which was calculated using standard plans with varying curvatures, ranging from flat to cylindrically circumferential. A plan was flagged if a discrepancy >10% was observed. Sensitivity and specificity were calculated using as a criteria for true positive that >10% of plan dwells had a distance to prescription dose >1 mm different than prescription depth (3 mm + size of applicator). All HDR image-based skin brachytherapy plans treated at our institution in 2013 were analyzed. Results: 108 surface applicator plans to treat skin of the face, scalp, limbs, feet, hands or abdomen were analyzed. Median number of catheters was 19 (range, 4 to 71) and median number of dwells was 257 (range, 20 to 1100). Sensitivity/specificity were 57%/78% for manual and 70%/89% for automatic verification. Conclusion: A check based on expected TRAK value is feasible for irregularly shaped, image-guided skin HDR brachytherapy. This test yielded higher sensitivity and specificity than a test based on the identification of representative points, and can be implemented with a dedicated calculation code or with pre-calculated lookup tables of ideally shaped, uniform surface applicators.

WE-DE-201-11: Sensitivity and Specificity of Verification Methods Based On Total Reference Air Kerma (TRAK) Or On User Provided Dose Points for Graphically Planned Skin HDR Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Damato, A; Devlin, P; Bhagwat, M; Buzurovic, I; Hansen, J; O’Farrell, D; Cormack, R [Harvard Medical School, Boston, MA (United States)

2016-06-15

Purpose: To investigate the sensitivity and specificity of a novel verification methodology for image-guided skin HDR brachytherapy plans using a TRAK-based reasonableness test, compared to a typical manual verification methodology. Methods: Two methodologies were used to flag treatment plans necessitating additional review due to a potential discrepancy of 3 mm between planned dose and clinical target in the skin. Manual verification was used to calculate the discrepancy between the average dose to points positioned at time of planning representative of the prescribed depth and the expected prescription dose. Automatic verification was used to calculate the discrepancy between TRAK of the clinical plan and its expected value, which was calculated using standard plans with varying curvatures, ranging from flat to cylindrically circumferential. A plan was flagged if a discrepancy >10% was observed. Sensitivity and specificity were calculated using as a criteria for true positive that >10% of plan dwells had a distance to prescription dose >1 mm different than prescription depth (3 mm + size of applicator). All HDR image-based skin brachytherapy plans treated at our institution in 2013 were analyzed. Results: 108 surface applicator plans to treat skin of the face, scalp, limbs, feet, hands or abdomen were analyzed. Median number of catheters was 19 (range, 4 to 71) and median number of dwells was 257 (range, 20 to 1100). Sensitivity/specificity were 57%/78% for manual and 70%/89% for automatic verification. Conclusion: A check based on expected TRAK value is feasible for irregularly shaped, image-guided skin HDR brachytherapy. This test yielded higher sensitivity and specificity than a test based on the identification of representative points, and can be implemented with a dedicated calculation code or with pre-calculated lookup tables of ideally shaped, uniform surface applicators.

SU-G-201-04: Can the Dynamic Library of Flap Applicators Replace Treatment Planning in Surface Brachytherapy?

Energy Technology Data Exchange (ETDEWEB)

Buzurovic, I; Devlin, P; Hansen, J; O’Farrell, D; Bhagwat, M; Friesen, S; Damato, A; Harris, T; Cormack, R [Dana-Farber/Brigham and Women’s Cancer Center, Harvard Medical School, Boston, MA (United States)

2016-06-15

Purpose: Contemporary brachytherapy treatment planning systems-(TPS) include the applicator model libraries to improve digitization; however, the library of surface-flap-applicators-(SFA) is not incorporated into the commercial TPS. We propose the dynamic library-(DL) for SFA and investigate if such library can eliminate applicator reconstruction, source activation and dose normalization. Methods: DL was generated for the SFA using the C++class libraries of the Visualization Toolkit-(VTK) and Qt-application framework for complete abstraction of the graphical interface. DL was designed such that the user can initially choose the size of the applicator that corresponds to the one clinically placed to the patient. The virtual applicator-(VA) has an elastic property so that it can be registered to the clinical CT images with a real applicator-(RA) on it. The VA and RA matching is performed by adjusting the position and curvature of the VA. The VA does not elongate or change its size so each catheter could always be at a distance of 5mm from the skin and 10mm apart from the closest catheter maintaining the physical accuracy of the clinical setup. Upon the applicator placement, the dwell positions were automatically activated, and the dose is normalized to the prescription depth. The accuracy of source positioning was evaluated using various applicator sizes. Results: The accuracy of the applicator placement was in the sub-millimeter range. The time-study reveals that up to 50% of the planning time can be saved depending on the complexity of the clinical setup. Unlike in the classic approach, the planning time was not highly dependent on the applicator size. Conclusion: The practical benefits of the DL of the SFA were demonstrated. The time demanding planning processes can be partially automated. Consequently, the planner can dedicate effort to fine tuning, which can result in the improvement of the quality of treatment plans in surface brachytherapy.

SU-G-201-04: Can the Dynamic Library of Flap Applicators Replace Treatment Planning in Surface Brachytherapy?

International Nuclear Information System (INIS)

Buzurovic, I; Devlin, P; Hansen, J; O’Farrell, D; Bhagwat, M; Friesen, S; Damato, A; Harris, T; Cormack, R

2016-01-01

Purpose: Contemporary brachytherapy treatment planning systems-(TPS) include the applicator model libraries to improve digitization; however, the library of surface-flap-applicators-(SFA) is not incorporated into the commercial TPS. We propose the dynamic library-(DL) for SFA and investigate if such library can eliminate applicator reconstruction, source activation and dose normalization. Methods: DL was generated for the SFA using the C++class libraries of the Visualization Toolkit-(VTK) and Qt-application framework for complete abstraction of the graphical interface. DL was designed such that the user can initially choose the size of the applicator that corresponds to the one clinically placed to the patient. The virtual applicator-(VA) has an elastic property so that it can be registered to the clinical CT images with a real applicator-(RA) on it. The VA and RA matching is performed by adjusting the position and curvature of the VA. The VA does not elongate or change its size so each catheter could always be at a distance of 5mm from the skin and 10mm apart from the closest catheter maintaining the physical accuracy of the clinical setup. Upon the applicator placement, the dwell positions were automatically activated, and the dose is normalized to the prescription depth. The accuracy of source positioning was evaluated using various applicator sizes. Results: The accuracy of the applicator placement was in the sub-millimeter range. The time-study reveals that up to 50% of the planning time can be saved depending on the complexity of the clinical setup. Unlike in the classic approach, the planning time was not highly dependent on the applicator size. Conclusion: The practical benefits of the DL of the SFA were demonstrated. The time demanding planning processes can be partially automated. Consequently, the planner can dedicate effort to fine tuning, which can result in the improvement of the quality of treatment plans in surface brachytherapy.

WE-DE-201-04: Cross Validation of Knowledge-Based Treatment Planning for Prostate LDR Brachytherapy Using Principle Component Analysis

Energy Technology Data Exchange (ETDEWEB)

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

2016-06-15

Purpose: To validate a knowledge-based algorithm for prostate LDR brachytherapy treatment planning. Methods: A dataset of 100 cases was compiled from an active prostate seed implant service. Cases were randomized into 10 subsets. For each subset, the 90 remaining library cases were registered to a common reference frame and then characterized on a point by point basis using principle component analysis (PCA). Each test case was converted to PCA vectors using the same process and 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. Any subsequent modifications were recorded that required input from a treatment planner to achieve V100>95%, V150<60%, V200<20%. To simulate operating-room planning constraints, seed activity was held constant, and the seed count could not increase. Results: The computational time required to register test-case contours and evaluate PCA similarity across the library was 10s. Preliminary analysis of 2 subsets shows that 9 of 20 test cases did not require any seed modifications to obtain an acceptable plan. Five test cases required fewer than 10 seed modifications or a grid shift. Another 5 test cases required approximately 20 seed modifications. An acceptable plan was not achieved for 1 outlier, which was substantially larger than its best match. Modifications took between 5s and 6min. Conclusion: A knowledge-based treatment planning algorithm for prostate LDR brachytherapy is being cross validated using 100 prior cases. Preliminary results suggest that for this size library, acceptable plans can be achieved without planner input in about half of the cases while varying amounts of planner input are needed in remaining cases. Computational time and planning time are compatible with clinical practice.

SU-F-T-15: Evaluation of 192Ir, 60Co and 169Yb Sources for High Dose Rate Prostate Brachytherapy Inverse Planning Using An Interior Point Constraint Generation Algorithm

Energy Technology Data Exchange (ETDEWEB)

Mok Tsze Chung, E; Aleman, D [University of Toronto, Toronto, Ontario (Canada); Safigholi, H; Nicolae, A; Davidson, M; Ravi, A; Song, W [Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada)

2016-06-15

Purpose: The effectiveness of using a combination of three sources, {sup 60}Co, {sup 192}Ir and {sup 169}Yb, is analyzed. Different combinations are compared against a single {sup 192}Ir source on prostate cancer cases. A novel inverse planning interior point algorithm is developed in-house to generate the treatment plans. Methods: Thirteen prostate cancer patients are separated into two groups: Group A includes eight patients with the prostate as target volume, while group B consists of four patients with a boost nodule inside the prostate that is assigned 150% of the prescription dose. The mean target volume is 35.7±9.3cc and 30.6±8.5cc for groups A and B, respectively. All patients are treated with each source individually, then with paired sources, and finally with all three sources. To compare the results, boost volume V150 and D90, urethra Dmax and D10, and rectum Dmax and V80 are evaluated. For fair comparison, all plans are normalized to a uniform V100=100. Results: Overall, double- and triple-source plans were better than single-source plans. The triple-source plans resulted in an average decrease of 21.7% and 1.5% in urethra Dmax and D10, respectively, and 8.0% and 0.8% in rectum Dmax and V80, respectively, for group A. For group B, boost volume V150 and D90 increased by 4.7% and 3.0%, respectively, while keeping similar dose delivered to the urethra and rectum. {sup 60}Co and {sup 192}Ir produced better plans than their counterparts in the double-source category, whereas {sup 60}Co produced more favorable results than the remaining individual sources. Conclusion: This study demonstrates the potential advantage of using a combination of two or three sources, reflected in dose reduction to organs-at-risk and more conformal dose to the target. three sources, reflected in dose reduction to organs-at-risk and more conformal dose to the target. Our results show that {sup 60}Co, {sup 192}Ir and {sup 169}Yb produce the best plans when used simultaneously and

WE-DE-201-02: A Statistical Analysis Tool for Plan Quality Verification in HDR Brachytherapy Forward Planning for Cervix Cancer

Energy Technology Data Exchange (ETDEWEB)

Ma, R; Zhu, X; Li, S; Zheng, D; Lei, Y; Wang, S; Verma, V; Bennion, N; Wahl, A; Zhou, S [University of Nebraska Medical Center, Omaha, NE (United States)

2016-06-15

Purpose: High Dose Rate (HDR) brachytherapy forward planning is principally an iterative process; hence, plan quality is affected by planners’ experiences and limited planning time. Thus, this may lead to sporadic errors and inconsistencies in planning. A statistical tool based on previous approved clinical treatment plans would help to maintain the consistency of planning quality and improve the efficiency of second checking. Methods: An independent dose calculation tool was developed from commercial software. Thirty-three previously approved cervical HDR plans with the same prescription dose (550cGy), applicator type, and treatment protocol were examined, and ICRU defined reference point doses (bladder, vaginal mucosa, rectum, and points A/B) along with dwell times were collected. Dose calculation tool then calculated appropriate range with a 95% confidence interval for each parameter obtained, which would be used as the benchmark for evaluation of those parameters in future HDR treatment plans. Model quality was verified using five randomly selected approved plans from the same dataset. Results: Dose variations appears to be larger at the reference point of bladder and mucosa as compared with rectum. Most reference point doses from verification plans fell between the predicted range, except the doses of two points of rectum and two points of reference position A (owing to rectal anatomical variations & clinical adjustment in prescription points, respectively). Similar results were obtained for tandem and ring dwell times despite relatively larger uncertainties. Conclusion: This statistical tool provides an insight into clinically acceptable range of cervical HDR plans, which could be useful in plan checking and identifying potential planning errors, thus improving the consistency of plan quality.

Conformal three dimensional radiotherapy treatment planning in Lund

Energy Technology Data Exchange (ETDEWEB)

Knoos, T; Nilsson, P [Lund Univ. (Sweden). Dept. of Radiation Physics; Anders, A [Lund Univ. (Sweden). Dept. of Oncology

1995-12-01

The use of conformal therapy is based on 3-dimensional treatment planning as well as on methods and routines for 3-dimensional patient mapping, 3-dimensional virtual simulation and others. The management of patients at the Radiotherapy Department at the University Hospital in Lund (Sweden) is discussed. About 2100 new patients are annually treated with external radiotherapy using seven linear accelerators. Three of the accelerators have dual photon energies and electron treatment facilities. A multi-leaf collimator as well as an electronic portal imaging device are available on one machine. Two simulators and an in-house CT-scanner are used for treatment planning. From 1988 to 1992 Scandiplan (Umplan) was used. Since 1992, the treatment planning system is TMS (HELAX AB, Sweden), which is based on the pencil beam algorithm of Ahnesjo. The calculations use patient modulated accelerator specific energy fluence spectra which are compiled with pencil beams from Monte Carlo generated energy absorption kernels. Heterogeneity corrections are performed with results close to conventional algorithms. Irregular fields, either from standard or individual blocks and from multi-leaf collimators are handled by the treatment planning system. The field shape is determined conveniently using the beam`s eye view. The final field shape is exported electronically to either the block cutting machine or the multileaf collimator control computer. All patient fields are checked against the beam`s eye view during simulation using manual methods. Treatment verification is performed by portal films and in vivo dosimetry with silicon diodes or TL-dosimetry. Up to now, approximately 4400 patients have received a highly individualized 3-dimensional conformal treatment.

MO-A-BRB-00: Electronic Charting in EBRT and Brachytherapy

International Nuclear Information System (INIS)

2015-01-01

The process of converting to an electronic chart for radiation therapy can be daunting. It requires a dedicated committee to first research and choose appropriate software, to review the entire documentation policy and flow of the clinic, to convert this system to electronic form or if necessary, redesign the system to more easily conform to the electronic process. Those making the conversion and those who already use electronic charting would benefit from the shared experience of those who have been through the process in the past. Therefore TG262 was convened to provide guidance on electronic charting for external beam radiation therapy and brachytherapy. This course will present the results of an internal survey of task group members on EMR practices in External Beam Radiation Therapy as well as discuss important issues in EMR development and structure for both EBRT and brachytherapy. Learning Objectives: Be familiarized with common practices and pitfalls in development and maintenance of an electronic chart in Radiation Oncology Be familiarized with important issues related to electronic charting in External Beam Radiation Therapy Be familiarized with important issues related to electronic charting in Brachytherapy

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.

Keeping an eye on the ring: COMS plaque loading optimization for improved dose conformity and homogeneity.

Science.gov (United States)

Gagne, Nolan L; Cutright, Daniel R; Rivard, Mark J

2012-09-01

To improve tumor dose conformity and homogeneity for COMS plaque brachytherapy by investigating the dosimetric effects of varying component source ring radionuclides and source strengths. The MCNP5 Monte Carlo (MC) radiation transport code was used to simulate plaque heterogeneity-corrected dose distributions for individually-activated source rings of 14, 16 and 18 mm diameter COMS plaques, populated with (103)Pd, (125)I and (131)Cs sources. Ellipsoidal tumors were contoured for each plaque size and MATLAB programming was developed to generate tumor dose distributions for all possible ring weighting and radionuclide permutations for a given plaque size and source strength resolution, assuming a 75 Gy apical prescription dose. These dose distributions were analyzed for conformity and homogeneity and compared to reference dose distributions from uniformly-loaded (125)I plaques. The most conformal and homogeneous dose distributions were reproduced within a reference eye environment to assess organ-at-risk (OAR) doses in the Pinnacle(3) treatment planning system (TPS). The gamma-index analysis method was used to quantitatively compare MC and TPS-generated dose distributions. Concentrating > 97% of the total source strength in a single or pair of central (103)Pd seeds produced the most conformal dose distributions, with tumor basal doses a factor of 2-3 higher and OAR doses a factor of 2-3 lower than those of corresponding uniformly-loaded (125)I plaques. Concentrating 82-86% of the total source strength in peripherally-loaded (131)Cs seeds produced the most homogeneous dose distributions, with tumor basal doses 17-25% lower and OAR doses typically 20% higher than those of corresponding uniformly-loaded (125)I plaques. Gamma-index analysis found > 99% agreement between MC and TPS dose distributions. A method was developed to select intra-plaque ring radionuclide compositions and source strengths to deliver more conformal and homogeneous tumor dose distributions than

Novel Use of the Contura for High Dose Rate Cranial Brachytherapy

International Nuclear Information System (INIS)

Scanderbeg, Daniel J.; Alksne, John F.; Lawson, Joshua D.; Murphy, Kevin T.

2011-01-01

A popular choice for treatment of recurrent gliomas was cranial brachytherapy using the GliaSite Radiation Therapy System. However, this device was taken off the market in late 2008, thus leaving a treatment void. This case study presents our experience treating a cranial lesion for the first time using a Contura multilumen, high-dose-rate (HDR) brachytherapy balloon applicator. The patient was a 47-year-old male who was diagnosed with a recurrent right frontal anaplastic oligodendroglioma. Previous radiosurgery made him a good candidate for brachytherapy. An intracavitary HDR balloon brachytherapy device (Contura) was placed in the resection cavity and treated with a single fraction of 20 Gy. The implant, treatment, and removal of the device were all completed without incident. Dosimetry of the device was excellent because the dose conformed very well to the target. V90, V100, V150, and V200 were 98.9%, 95.7%, 27.2, and 8.8 cc, respectively. This patient was treated successfully using the Contura multilumen balloon. Contura was originally designed for deployment in a postlumpectomy breast for treatment by accelerated partial breast irradiation. Being an intracavitary balloon device, its similarity to the GliaSite system makes it a viable replacement candidate. Multiple lumens in the device also make it possible to shape the dose delivered to the target, something not possible before with the GliaSite applicator.

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

Preparation of a program for the independent verification of the brachytherapy planning systems calculations; Confeccion de un programa para la verificacion independiente de los calculos de los sistemas de planificacion en braquiterapia

Energy Technology Data Exchange (ETDEWEB)

V Carmona, V.; Perez-Calatayud, J.; Lliso, F.; Richart Sancho, J.; Ballester, F.; Pujades-Claumarchirant, M.C.; Munoz, M.

2010-07-01

In this work a program is presented that independently checks for each patient the treatment planning system calculations in low dose rate, high dose rate and pulsed dose rate brachytherapy. The treatment planning system output text files are automatically loaded in this program in order to get the source coordinates, the desired calculation point coordinates and the dwell times when it is the case. The source strength and the reference dates are introduced by the user. The program allows implementing the recommendations about independent verification of the clinical brachytherapy dosimetry in a simple and accurate way, in few minutes. (Author).

Treatment planning for prostate brachytherapy using region of interest adjoint functions and a greedy heuristic

International Nuclear Information System (INIS)

Yoo, Sua; Kowalok, Michael E; Thomadsen, Bruce R; Henderson, Douglass L

2003-01-01

We have developed an efficient treatment-planning algorithm for prostate implants that is based on region of interest (ROI) adjoint functions and a greedy heuristic. For this work, we define the adjoint function for an ROI as the sensitivity of the average dose in the ROI to a unit-strength brachytherapy source at any seed position. The greedy heuristic uses a ratio of target and critical structure adjoint functions to rank seed positions according to their ability to irradiate the target ROI while sparing critical structure ROIs. This ratio is computed once for each seed position prior to the optimization process. Optimization is performed by a greedy heuristic that selects seed positions according to their ratio values. With this method, clinically acceptable treatment plans are obtained in less than 2 s. For comparison, a branch-and-bound method to solve a mixed integer-programming model took more than 50 min to arrive at a feasible solution. Both methods achieved good treatment plans, but the speedup provided by the greedy heuristic was a factor of approximately 1500. This attribute makes this algorithm suitable for intra-operative real-time treatment planning

SU-F-T-420: Dosimetry Comparison of Advanced External Beam Radiation Treatment Modalities to Brachytherapy Treatments in Patients with Cervical Cancer

Energy Technology Data Exchange (ETDEWEB)

Mwidu, U; Devic, S [McGill University, Montreal, QC (Canada); Shehadeh, M; AlKafi, M; Mahmood, R; Moftah, B [King Faisal Specialist Hospital & Research Center, Riyadh, Riyadh (Saudi Arabia)

2016-06-15

Purpose: A retrospective comparison of dose distributions achievable by High dose rate brachytherapy (HDRBT), Helical TomoTherapy (TOMO), CyberKnife (CK) and RapidArc (RA) in locally advanced inoperable cervical cancer patients is presented. Methods: Five patients with advanced stage cervical carcinoma were selected for this study after a full course of external beam radiotherapy (EBRT), chemotherapy and HDR Brachytherapy. To highlight any significant similarities/differences in dose distributions, high-risk clinical target volume (HRCTV) coverage, organs at risk (OAR) sparing, and machine specific delivery limitations, we used D90 (dose received by 90% of the volume) as the parameter for HRCTV coverage as recommended by the GEC-ESTRO Working Group. We also compared both integral and differential dose volume histograms (DVH) between different dose distributions treatment modalities for HRCTV and OAR. Results: TOMO and RA provided the most conformal dose distributions to HRCTV. Median doses (in Gy) to organs at risk were; for rectal wall: 1.7±0.6, 2.5±0.6,1.2±0.3, and 1.5±0.6, and for bladder wall: 1.6±0.1, 2.4±0.4, 0.8±0.6, and 1.5±0.5, for HDRBT, TOMO, CK, and RA, respectively. Conclusion: Contemporary EBRT modalities might be able to replace brachytherapy treatments for cervix cancer. While brachytherapy dose distributions feature high dose gradients, EBRT modalities provide highly conformal dose distributions to the target. However, it is still not clear whether a highly conformal dose or high gradient dose is more clinically relevant for the HRCTV in cervix cancer patients.

A multicentre ‘end to end’ dosimetry audit for cervix HDR brachytherapy treatment

International Nuclear Information System (INIS)

Palmer, Antony L.; Diez, Patricia; Gandon, Laura; Wynn-Jones, Andrea; Bownes, Peter; Lee, Chris; Aird, Edwin; Bidmead, Margaret; Lowe, Gerry; Bradley, David; Nisbet, Andrew

2015-01-01

Purpose: To undertake the first multicentre fully ‘end to end’ dosimetry audit for HDR cervix brachytherapy, comparing planned and delivered dose distributions around clinical treatment applicators, with review of local procedures. Materials and methods: A film-dosimetry audit was performed at 46 centres, including imaging, applicator reconstruction, treatment planning and delivery. Film dose maps were calculated using triple-channel dosimetry and compared to RTDose data from treatment planning systems. Deviations between plan and measurement were quantified at prescription Point A and using gamma analysis. Local procedures were also discussed. Results: The mean difference between planned and measured dose at Point A was −0.6% for plastic applicators and −3.0% for metal applicators, at standard uncertainty 3.0% (k = 1). Isodose distributions agreed within 1 mm over a dose range 2–16 Gy. Mean gamma passing rates exceeded 97% for plastic and metal applicators at 3% (local) 2 mm criteria. Two errors were found: one dose normalisation error and one applicator library misaligned with the imaged applicator. Suggestions for quality improvement were also made. Conclusions: The concept of ‘end to end’ dosimetry audit for HDR brachytherapy has been successfully implemented in a multicentre environment, providing evidence that a high level of accuracy in brachytherapy dosimetry can be achieved

Novel use of ViewRay MRI guidance for high-dose-rate brachytherapy in the treatment of cervical cancer.

Science.gov (United States)

Ko, Huaising C; Huang, Jessie Y; Miller, Jessica R; Das, Rupak K; Wallace, Charles R; De Costa, Anna-Maria A; Francis, David M; Straub, Margaret R; Anderson, Bethany M; Bradley, Kristin A

To characterize image quality and feasibility of using ViewRay MRI (VR)-guided brachytherapy planning for cervical cancer. Cervical cancer patients receiving intracavitary brachytherapy with tandem and ovoids, planned using 0.35T VR MRI at our institution, were included in this series. The high-risk clinical target volume (HR-CTV), visible gross tumor volume, bladder, sigmoid, bowel, and rectum contours for each fraction of brachytherapy were evaluated for dosimetric parameters. Typically, five brachytherapy treatments were planned using the T2 sequence on diagnostic MRI for the first and third fractions, and a noncontrast true fast imaging with steady-state precession sequence on VR or CT scan for the remaining fractions. Most patients received 5.5 Gy × 5 fractions using high-dose-rate Ir-192 following 45 Gy of whole-pelvis radiotherapy. The plan was initiated at 5.5 Gy to point A and subsequently optimized and prescribed to the HR-CTV. The goal equivalent dose in 2 Gy fractions for the combined external beam and brachytherapy dose was 85 Gy. Soft-tissue visualization using contrast-to-noise ratios to distinguish normal tissues from tumor at their interface was compared between diagnostic MRI, CT, and VR. One hundred and forty-two fractions of intracavitary brachytherapy were performed from April 2015 to January 2017 on 29 cervical cancer patients, ranging from stages IB1 to IVA. The median HR-CTV was 27.78 cc, with median D 90 HR-CTV of 6.1 Gy. The median time from instrument placement to start of treatment using VR was 65 min (scan time 2 min), compared to 105 min using diagnostic MRI (scan time 11 min) (t-test, p < 0.01). The contrast-to-noise ratio of tumor to cervix in both diagnostic MRI and VR had significantly higher values compared to CT (ANOVA and t-tests, p < 0.01). We report the first clinical use of VR-guided brachytherapy. Time to treatment using this approach was shorter compared to diagnostic MRI. VR also provided significant

Direction Modulated Brachytherapy for Treatment of Cervical Cancer. II: Comparative Planning Study With Intracavitary and Intracavitary–Interstitial Techniques

Energy Technology Data Exchange (ETDEWEB)

Han, Dae Yup [Department of Medical Physics, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Department of Radiation Oncology, University of California, San Francisco, San Francisco, California (United States); Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California (United States); Safigholi, Habib; Soliman, Abraam [Department of Medical Physics, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario (Canada); Ravi, Ananth [Department of Medical Physics, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Leung, Eric [Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Scanderbeg, Daniel J. [Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California (United States); Liu, Zhaowei [Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California (United States); Owrangi, Amir [Department of Medical Physics, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Song, William Y., E-mail: william.song@sunnybrook.ca [Department of Medical Physics, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada)

2016-10-01

Purpose: To perform a comprehensive comparative planning study evaluating the utility of the proposed direction modulated brachytherapy (DMBT) tandem applicator against standard applicators, in the setting of image guided adaptive brachytherapy of cervical cancer. Methods and Materials: A detailed conceptual article was published in 2014. The proposed DMBT tandem applicator has 6 peripheral grooves of 1.3-mm width, along a 5.4-mm-thick nonmagnetic tungsten alloy rod of density 18.0 g/cm{sup 3}, capable of generating directional dose profiles. We performed a comparative planning study with 45 cervical cancer patients enrolled consecutively in the prospective observational EMBRACE study. In all patients, MRI-based planning was performed while utilizing various tandem-ring (27 patients) and tandem-ring-needles (18 patients) applicators, in accordance with the Groupe Européen de Curiethérapie–European Society for Radiotherapy and Oncology recommendations. For unbiased comparisons, all cases were replanned with an in-house–developed inverse optimization code while enforcing a uniform set of constraints that are reflective of the clinical practice. All plans were normalized to the same high-risk clinical target volume D90 values achieved in the original clinical plans. Results: In general, if the standard tandem was replaced with the DMBT tandem while maintaining all other planning conditions the same, there was consistent improvement in the plan quality. For example, among the 18 tandem-ring-needles cases, the average D2cm{sup 3} reductions achieved were −2.48% ± 11.03%, −4.45% ± 5.24%, and −5.66% ± 6.43% for the bladder, rectum, and sigmoid, respectively. An opportunity may also exist in avoiding use of needles altogether for when the total number of needles required is small (approximately 2 to 3 needles or less), if DMBT tandem is used. Conclusions: Integrating the novel DMBT tandem onto both intracavitary and intracavitary�

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

Frustration-guided motion planning reveals conformational transitions in proteins.

Science.gov (United States)

Budday, Dominik; Fonseca, Rasmus; Leyendecker, Sigrid; van den Bedem, Henry

2017-10-01

Proteins exist as conformational ensembles, exchanging between substates to perform their function. Advances in experimental techniques yield unprecedented access to structural snapshots of their conformational landscape. However, computationally modeling how proteins use collective motions to transition between substates is challenging owing to a rugged landscape and large energy barriers. Here, we present a new, robotics-inspired motion planning procedure called dCC-RRT that navigates the rugged landscape between substates by introducing dynamic, interatomic constraints to modulate frustration. The constraints balance non-native contacts and flexibility, and instantaneously redirect the motion towards sterically favorable conformations. On a test set of eight proteins determined in two conformations separated by, on average, 7.5 Å root mean square deviation (RMSD), our pathways reduced the Cα atom RMSD to the goal conformation by 78%, outperforming peer methods. We then applied dCC-RRT to examine how collective, small-scale motions of four side-chains in the active site of cyclophilin A propagate through the protein. dCC-RRT uncovered a spatially contiguous network of residues linked by steric interactions and collective motion connecting the active site to a recently proposed, non-canonical capsid binding site 25 Å away, rationalizing NMR and multi-temperature crystallography experiments. In all, dCC-RRT can reveal detailed, all-atom molecular mechanisms for small and large amplitude motions. Source code and binaries are freely available at https://github.com/ExcitedStates/KGS/. © 2017 Wiley Periodicals, Inc.

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.

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

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

International Nuclear Information System (INIS)

Balvert, Marleen; Gorissen, Bram L; Den Hertog, Dick; Hoffmann, Aswin L

2015-01-01

Inverse planning algorithms for dwell time optimisation in interstitial high-dose-rate (HDR) brachytherapy may produce solutions with large dwell time variations within catheters, which may result in undesirable selective high-dose subvolumes. Extending the dwell time optimisation model with a dwell time modulation restriction (DTMR) that limits dwell time differences between neighboring dwell positions has been suggested to eliminate this problem. DTMRs may additionally reduce the sensitivity for uncertainties in dwell positions that inevitably result from catheter reconstruction errors and afterloader source positioning inaccuracies. This study quantifies the reduction of high-dose subvolumes and the robustness against these uncertainties by applying a DTMR to template-based prostate HDR brachytherapy implants. Three different DTMRs were consecutively applied to a linear dose-based penalty model (LD) and a dose-volume based model (LDV), both obtained from literature. The models were solved with DTMR levels ranging from no restriction to uniform dwell times within catheters in discrete steps. Uncertainties were simulated on clinical cases using in-house developed software, and dose-volume metrics were calculated in each simulation. For the assessment of high-dose subvolumes, the dose homogeneity index (DHI) and the contiguous dose volume histogram were analysed. Robustness was measured by the improvement of the lowest D 90% of the planning target volume (PTV) observed in the simulations. For (LD), a DTMR yields an increase in DHI of approximately 30% and reduces the size of the largest high-dose volume by 2–5 cc. However, this comes at a cost of a reduction in D 90% of the PTV of 10%, which often implies that it drops below the desired minimum of 100%. For (LDV), none of the DTMRs were able to improve high-dose volume measures. DTMRs were not capable of improving robustness of PTV D 90% against uncertainty in dwell positions for both models. (paper)

Using the computed tomography in comparison to the orthogonal radiography based treatment planning in high dose rate (HDR) brachytherapy in cervical uteri cancer patients; a single institution feasibility study.

Science.gov (United States)

Bahadur, Yasir A; El-Sayed, Mohamed E; El-Taher, Zeinab H; Zaza, Khaled O; Moftah, Belal A; Hassouna, Ashraf H; Ghassal, Noor M

2008-03-01

Brachytherapy is an integral part in the treatment of cervical uteri cancer patients. Orthogonal treatment planning is the standard mode of calculation based on reference points. Introduction of the innovative 3-D computer based treatment planning allows accurate calculation based on volumetric information as regards the target volume and organs at risk (OAR). Also provide dose volume histogram (DVH) for proper estimation of the dose in relation to the volume. To correlate and compare the information obtained from the two approaches for high dose rate brachytherapy of cervical uteri cancer; the orthogonal conventional method and the computerized tomography (CT) three dimensions (3D) based calculation method in relation to the target and organ at risk (OAR). From 6 patients of cervical uteri cancer, 21 applications with orthogonal planning using the Brachy Vision treatment planning system version 7.3.10 were performed. In 10 applications; comparison between orthogonal and CT based planning was done. In orthogonal planning; the dose to point A, rectum and bladder were defined according to the American Brachytherapy Society (ABS) recommendation. From the CT based planning the target volume and dose volume histogram lpar;DVH) were calculated for the clinical target volume (CTV), rectum and bladder. From these two sets, information was obtained and compared and mean values were derived. For dose prescription at point A, an average of 63.5% of CTV received the prescribed dose. The mean ICRU dose to the bladder point is 2.9 Gy+/-1.2 SD (Standard Deviation) and 17% of the bladder volume derived from CT was encompassed by 2.9 Gy isodose line. The mean ICRU dose at the rectum point is 3.4 Gy+/-1.2 SD and 21% of the rectum volume from CT was encompassed by 3.4 Gy isodose line. The maximum dose to the rectum and the bladder derived from the CT and compared to the maximal dose at ICRU is 1.7 and 2.8 times higher than the orthogonal reference points; with the corresponding p

Using the Computed Tomography in Comparison to the Orthogonal Radiography Based Treatment Planning in High dose Rate (HDR) Brachytherapy in Cervical Uteri Cancer Patients; A Single Institution Feasibility Study

International Nuclear Information System (INIS)

BAHADUR, Y.A.; EL-SAYED, M.E.; HASSOUNA, A.H.; EL-TAHER, Z.H.; GHASSAL, N.M.; ZAZA, Kh.O.M.D.; OFTAH, B.A.

2008-01-01

Brachytherapy is an integral part in the treatment of cervical uteri cancer patients. Orthogonal treatment planning is the standard mode of calculation based on reference points. Introduction of the innovative 3-D computer based treatment planning allows accurate calculation based on volumetric information as regards the target volume and organs at risk (OAR). Also provide dose volume histogram (DVH) for proper estimation of the dose in relation to the volume. Aim: To correlate and compare the information obtained from the two approaches for high dose rate brachytherapy of cervical uteri cancer; the orthogonal conventional method and the computerized tomography (CT) three dimensions (3D) based calculation method in relation to the target and organ at risk (OAR). Methods: From 6 patients of cervical uteri cancer, 21 applications with orthogonal planning using the Brachy Vision treatment planning system version 7.3.10 were performed. In 10 applications; comparison between orthogonal and CT based planning was done. In orthogonal planning; the dose to point A, rectum and bladder were defined according to the American Brachytherapy Society (ABS) recommendation. From the CT based planning the target volume and dose volume histogram (DVH) were calculated for the clinical target volume (CTV), rectum and bladder. From these two sets, information was obtained and compared and mean values were derived. Results: For dose prescription at point A, an average of 63.5% of CTV received the prescribed dose. The mean ICRU dose to the bladder point is 2.9 Gy±l .2 SD (Standard Deviation) and 17% of the bladder volume derived from CT was encompassed by 2.9 Gy isodose line. The mean ICRU dose at the rectum point is 3.4 Gy±1.2 SD and 21% of the rectum volume from CT was encompassed by 3.4 Gy isodose line. The maximum dose to the rectum and the bladder derived from the CT and compared to the maximal dose at ICRU is 1.7 and 2.8 times higher than the orthogonal reference points; with the

SU-E-T-397: Include Organ Deformation Into Dose Calculation of Prostate Brachytherapy

International Nuclear Information System (INIS)

Shao, Y; Shen, D; Chen, R; Wang, A; Lian, J

2014-01-01

Purpose: Prostate brachytherapy is an important curative treatment for patients with localized prostate cancer. In brachytherapy, rectal balloon is generally needed to adjust for unfavorable prostate position for seed placement. However, rectal balloon causes prostate deformation, which is not accounted for in dosimetric planning. Therefore, it is possible that brachytherapy dosimetry deviates significantly from initial plan when prostate returns to its non-deformed state (after procedure). The goal of this study is to develop a method to include prostate deformation into the treatment planning of brachytherapy dosimetry. Methods: We prospectively collected ultrasound images of prostate pre- and post- rectal balloon inflation from thirty five consecutive patients undergoing I-125 brachytherapy. Based on the cylinder coordinate systems, we learned the initial coordinate transformation parameters between the manual segmentations of both deformed and non-deformed prostates of each patient in training set. With the nearest-neighbor interpolation, we searched the best transformation between two coordinate systems to maximum the mutual information of deformed and non-deformed images. We then mapped the implanted seeds of five selected patients from the deformed prostate into non-deformed prostate. The seed position is marked on original pre-inflation US image and it is imported into VariSeed software for dose calculation. Results: The accuracy of image registration is 87.5% as quantified by Dice Index. The prostate coverage V100% dropped from 96.5±0.5% of prostate deformed plan to 91.9±2.6% (p<0.05) of non-deformed plan. The rectum V100% decreased from 0.44±0.26 cc to 0.10±0.18 cc (p<0.05). The dosimetry of the urethra showed mild change but not significant: V150% changed from 0.05±0.10 cc to 0.14±0.15 cc (p>0.05) and D1% changed from 212.9±37.3 Gy to 248.4±42.8 Gy (p>0.05). Conclusion: We have developed a deformable image registration method that allows

Dosimetric equivalence of nonstandard HDR brachytherapy catheter patterns

International Nuclear Information System (INIS)

Cunha, J. A. M.; Hsu, I-C.; Pouliot, J.

2009-01-01

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

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

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

Spine stereotactic body radiation therapy plans: Achieving dose coverage, conformity, and dose falloff

International Nuclear Information System (INIS)

Hong, Linda X.; Shankar, Viswanathan; Shen, Jin; Kuo, Hsiang-Chi; Mynampati, Dinesh; Yaparpalvi, Ravindra; Goddard, Lee; Basavatia, Amar; Fox, Jana; Garg, Madhur; Kalnicki, Shalom; Tomé, Wolfgang A.

2015-01-01

We report our experience of establishing planning objectives to achieve dose coverage, conformity, and dose falloff for spine stereotactic body radiation therapy (SBRT) plans. Patients with spine lesions were treated using SBRT in our institution since September 2009. Since September 2011, we established the following planning objectives for our SBRT spine plans in addition to the cord dose constraints: (1) dose coverage—prescription dose (PD) to cover at least 95% planning target volume (PTV) and 90% PD to cover at least 99% PTV; (2) conformity index (CI)—ratio of prescription isodose volume (PIV) to the PTV < 1.2; (3) dose falloff—ratio of 50% PIV to the PTV (R 50% ); (4) and maximum dose in percentage of PD at 2 cm from PTV in any direction (D 2cm ) to follow Radiation Therapy Oncology Group (RTOG) 0915. We have retrospectively reviewed 66 separate spine lesions treated between September 2009 and December 2012 (31 treated before September 2011 [group 1] and 35 treated after [group 2]). The χ 2 test was used to examine the difference in parameters between groups. The PTV V 100% PD ≥ 95% objective was met in 29.0% of group 1 vs 91.4% of group 2 (p < 0.01) plans. The PTV V 90% PD ≥ 99% objective was met in 38.7% of group 1 vs 88.6% of group 2 (p < 0.01) plans. Overall, 4 plans in group 1 had CI > 1.2 vs none in group 2 (p = 0.04). For D 2cm , 48.3% plans yielded a minor violation of the objectives and 16.1% a major violation for group 1, whereas 17.1% exhibited a minor violation and 2.9% a major violation for group 2 (p < 0.01). Spine SBRT plans can be improved on dose coverage, conformity, and dose falloff employing a combination of RTOG spine and lung SBRT protocol planning objectives

Spine stereotactic body radiation therapy plans: Achieving dose coverage, conformity, and dose falloff

Energy Technology Data Exchange (ETDEWEB)

Hong, Linda X., E-mail: lhong0812@gmail.com [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY (United States); Shankar, Viswanathan [Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY (United States); Shen, Jin [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Kuo, Hsiang-Chi [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY (United States); Mynampati, Dinesh [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Yaparpalvi, Ravindra [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY (United States); Goddard, Lee [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Basavatia, Amar; Fox, Jana; Garg, Madhur; Kalnicki, Shalom; Tomé, Wolfgang A. [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY (United States)

2015-10-01

We report our experience of establishing planning objectives to achieve dose coverage, conformity, and dose falloff for spine stereotactic body radiation therapy (SBRT) plans. Patients with spine lesions were treated using SBRT in our institution since September 2009. Since September 2011, we established the following planning objectives for our SBRT spine plans in addition to the cord dose constraints: (1) dose coverage—prescription dose (PD) to cover at least 95% planning target volume (PTV) and 90% PD to cover at least 99% PTV; (2) conformity index (CI)—ratio of prescription isodose volume (PIV) to the PTV < 1.2; (3) dose falloff—ratio of 50% PIV to the PTV (R{sub 50%}); (4) and maximum dose in percentage of PD at 2 cm from PTV in any direction (D{sub 2cm}) to follow Radiation Therapy Oncology Group (RTOG) 0915. We have retrospectively reviewed 66 separate spine lesions treated between September 2009 and December 2012 (31 treated before September 2011 [group 1] and 35 treated after [group 2]). The χ{sup 2} test was used to examine the difference in parameters between groups. The PTV V{sub 100%} {sub PD} ≥ 95% objective was met in 29.0% of group 1 vs 91.4% of group 2 (p < 0.01) plans. The PTV V{sub 90%} {sub PD} ≥ 99% objective was met in 38.7% of group 1 vs 88.6% of group 2 (p < 0.01) plans. Overall, 4 plans in group 1 had CI > 1.2 vs none in group 2 (p = 0.04). For D{sub 2cm}, 48.3% plans yielded a minor violation of the objectives and 16.1% a major violation for group 1, whereas 17.1% exhibited a minor violation and 2.9% a major violation for group 2 (p < 0.01). Spine SBRT plans can be improved on dose coverage, conformity, and dose falloff employing a combination of RTOG spine and lung SBRT protocol planning objectives.

Dosimetric and Radiobiologic Comparison of 3D Conformal Versus Intensity Modulated Planning Techniques for Prostate Bed Radiotherapy

International Nuclear Information System (INIS)

Koontz, Bridget F.; Das, Shiva; Temple, Kathy; Bynum, Sigrun; Catalano, Suzanne; Koontz, Jason I.; Montana, Gustavo S.; Oleson, James R.

2009-01-01

Adjuvant radiotherapy for locally advanced prostate cancer improves biochemical and clinical disease-free survival. While comparisons in intact prostate cancer show a benefit for intensity modulated radiation therapy (IMRT) over 3D conformal planning, this has not been studied for post-prostatectomy radiotherapy (RT). This study compares normal tissue and target dosimetry and radiobiological modeling of IMRT vs. 3D conformal planning in the postoperative setting. 3D conformal plans were designed for 15 patients who had been treated with IMRT planning for salvage post-prostatectomy RT. The same computed tomography (CT) and target/normal structure contours, as well as prescription dose, was used for both IMRT and 3D plans. Normal tissue complication probabilities (NTCPs) were calculated based on the dose given to the bladder and rectum by both plans. Dose-volume histogram and NTCP data were compared by paired t-test. Bladder and rectal sparing were improved with IMRT planning compared to 3D conformal planning. The volume of the bladder receiving at least 75% (V75) and 50% (V50) of the dose was significantly reduced by 28% and 17%, respectively (p = 0.002 and 0.037). Rectal dose was similarly reduced, V75 by 33% and V50 by 17% (p = 0.001 and 0.004). While there was no difference in the volume of rectum receiving at least 65 Gy (V65), IMRT planning significant reduced the volume receiving 40 Gy or more (V40, p = 0.009). Bladder V40 and V65 were not significantly different between planning modalities. Despite these dosimetric differences, there was no significant difference in the NTCP for either bladder or rectal injury. IMRT planning reduces the volume of bladder and rectum receiving high doses during post-prostatectomy RT. Because of relatively low doses given to the bladder and rectum, there was no statistically significant improvement in NTCP between the 3D conformal and IMRT plans.

Dosimetric and radiobiologic comparison of 3D conformal versus intensity modulated planning techniques for prostate bed radiotherapy.

Science.gov (United States)

Koontz, Bridget F; Das, Shiva; Temple, Kathy; Bynum, Sigrun; Catalano, Suzanne; Koontz, Jason I; Montana, Gustavo S; Oleson, James R

2009-01-01

Adjuvant radiotherapy for locally advanced prostate cancer improves biochemical and clinical disease-free survival. While comparisons in intact prostate cancer show a benefit for intensity modulated radiation therapy (IMRT) over 3D conformal planning, this has not been studied for post-prostatectomy radiotherapy (RT). This study compares normal tissue and target dosimetry and radiobiological modeling of IMRT vs. 3D conformal planning in the postoperative setting. 3D conformal plans were designed for 15 patients who had been treated with IMRT planning for salvage post-prostatectomy RT. The same computed tomography (CT) and target/normal structure contours, as well as prescription dose, was used for both IMRT and 3D plans. Normal tissue complication probabilities (NTCPs) were calculated based on the dose given to the bladder and rectum by both plans. Dose-volume histogram and NTCP data were compared by paired t-test. Bladder and rectal sparing were improved with IMRT planning compared to 3D conformal planning. The volume of the bladder receiving at least 75% (V75) and 50% (V50) of the dose was significantly reduced by 28% and 17%, respectively (p = 0.002 and 0.037). Rectal dose was similarly reduced, V75 by 33% and V50 by 17% (p = 0.001 and 0.004). While there was no difference in the volume of rectum receiving at least 65 Gy (V65), IMRT planning significant reduced the volume receiving 40 Gy or more (V40, p = 0.009). Bladder V40 and V65 were not significantly different between planning modalities. Despite these dosimetric differences, there was no significant difference in the NTCP for either bladder or rectal injury. IMRT planning reduces the volume of bladder and rectum receiving high doses during post-prostatectomy RT. Because of relatively low doses given to the bladder and rectum, there was no statistically significant improvement in NTCP between the 3D conformal and IMRT plans.

Source position verification and dosimetry in HDR brachytherapy using an EPID

International Nuclear Information System (INIS)

Smith, R. L.; Taylor, M. L.; McDermott, L. N.; Franich, R. D.; Haworth, A.; Millar, J. L.

2013-01-01

Purpose: Accurate treatment delivery in high dose rate (HDR) brachytherapy requires correct source dwell positions and dwell times to be administered relative to each other and to the surrounding anatomy. Treatment delivery inaccuracies predominantly occur for two reasons: (i) anatomical movement or (ii) as a result of human errors that are usually related to incorrect implementation of the planned treatment. Electronic portal imaging devices (EPIDs) were originally developed for patient position verification in external beam radiotherapy and their application has been extended to provide dosimetric information. The authors have characterized the response of an EPID for use with an 192 Ir brachytherapy source to demonstrate its use as a verification device, providing both source position and dosimetric information.Methods: Characterization of the EPID response using an 192 Ir brachytherapy source included investigations of reproducibility, linearity with dose rate, photon energy dependence, and charge build-up effects associated with exposure time and image acquisition time. Source position resolution in three dimensions was determined. To illustrate treatment verification, a simple treatment plan was delivered to a phantom and the measured EPID dose distribution compared with the planned dose.Results: The mean absolute source position error in the plane parallel to the EPID, for dwells measured at 50, 100, and 150 mm source to detector distances (SDD), was determined to be 0.26 mm. The resolution of the z coordinate (perpendicular distance from detector plane) is SDD dependent with 95% confidence intervals of ±0.1, ±0.5, and ±2.0 mm at SDDs of 50, 100, and 150 mm, respectively. The response of the EPID is highly linear to dose rate. The EPID exhibits an over-response to low energy incident photons and this nonlinearity is incorporated into the dose calibration procedure. A distance (spectral) dependent dose rate calibration procedure has been developed. The

Novel use of the Contura for high dose rate cranial brachytherapy.

Science.gov (United States)

Scanderbeg, Daniel J; Alksne, John F; Lawson, Joshua D; Murphy, Kevin T

2011-01-01

A popular choice for treatment of recurrent gliomas was cranial brachytherapy using the GliaSite Radiation Therapy System. However, this device was taken off the market in late 2008, thus leaving a treatment void. This case study presents our experience treating a cranial lesion for the first time using a Contura multilumen, high-dose-rate (HDR) brachytherapy balloon applicator. The patient was a 47-year-old male who was diagnosed with a recurrent right frontal anaplastic oligodendroglioma. Previous radiosurgery made him a good candidate for brachytherapy. An intracavitary HDR balloon brachytherapy device (Contura) was placed in the resection cavity and treated with a single fraction of 20 Gy. The implant, treatment, and removal of the device were all completed without incident. Dosimetry of the device was excellent because the dose conformed very well to the target. V90, V100, V150, and V200 were 98.9%, 95.7%, 27.2, and 8.8 cc, respectively. This patient was treated successfully using the Contura multilumen balloon. Contura was originally designed for deployment in a postlumpectomy breast for treatment by accelerated partial breast irradiation. Being an intracavitary balloon device, its similarity to the GliaSite system makes it a viable replacement candidate. Multiple lumens in the device also make it possible to shape the dose delivered to the target, something not possible before with the GliaSite applicator. Copyright © 2011 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

Evaluation of failure modes of computerized planning phase of interstitial implants with high dose rate brachytherapy using HFMEA

International Nuclear Information System (INIS)

Biazotto, Bruna; Tokarski, Marcio

2014-01-01

This paper evaluates the failure modes of the computerized planning step in interstitial implants with high dose rate brachytherapy. The prospective tool of risk management Health Care Failure Mode and Effects Analysis (HFMEA) was used. Twelve subprocesses were identified, and 33 failure modes of which 21 justified new safety actions, and 9 of them were intolerable risks. The method proved itself useful in identifying failure modes, but laborious and subjective in their assessment. The main risks were due to human factors, which require training and commitment of management to their mitigation. (author)

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

Optimal 3-D conformal treatment planning of posterior lateral supratentorial tumors

International Nuclear Information System (INIS)

Gius, David; Klein, Eric; Oehmke, Fred

1995-01-01

Purpose/Objective: The ability to treat the brain to greater doses is limited by normal brain tissue tolerance. With the use of 3-dimensional treatment planning dose escalation will result in increased target dose while sparing normal tissue. Treatment of the supratentorial region of the brain presents several unique difficulties due to the changing contour of the calvarium, which are especially noticeable with treatment to the posterior lateral quadrant. The use of a single wedge beam is sub-optimal and a more appropriate solution would employ a two tier wedge arrangement to better conform the isodoses around the target volume. In the past it has only been possible to use a single wedge during treatment with a single port, however, the dynamic wedge presents the opportunity to employ a two tier wedge system by simultaneously using conventional and dynamic wedging. Methods and Materials: An anthropomorphic phantom with a lesion located in the posterior lateral aspect of the brain where the external surface slopes at a maximum was configured. CT generated contours outlined the external surface, normal anatomy, gross tumor, and target volumes. We used the beam's-eye-view projection from the 3D planning system to derive the conformal beams. A standard opposed lateral and posterior oblique wedge pair beam arrangements, were compared to a three field technique (PA, lateral, and vertex) which used both a single wedge arrangement and a two-tier wedge plan. Treatment plans were evaluated by calculating isodose distribution, DVH, TCP, and NTCP. Each beam arrangement was used to treat our phantom with film placed in between the phantom layers at the tumor levels to confirm the accuracy of the 3-D system calculations. Results: The three field, two-tier wedge technique isodose distribution was significantly superior when compared to the standard 2-D plans, and a moderate improvement over the three field, single wedge technique in terms of conforming dose to the tumor and

SU-G-201-15: Nomogram as an Efficient Dosimetric Verification Tool in HDR Prostate Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Liang, J; Todor, D [Virginia Commonwealth University, Richmond, VA (United States)

2016-06-15

Purpose: Nomogram as a simple QA tool for HDR prostate brachytherapy treatment planning has been developed and validated clinically. Reproducibility including patient-to-patient and physician-to-physician variability was assessed. Methods: The study was performed on HDR prostate implants from physician A (n=34) and B (n=15) using different implant techniques and planning methodologies. A nomogram was implemented as an independent QA of computer-based treatment planning before plan execution. Normalized implant strength (total air kerma strength Sk*t in cGy cm{sup 2} divided by prescribed dose in cGy) was plotted as a function of PTV volume and total V100. A quadratic equation was used to fit the data with R{sup 2} denoting the model predictive power. Results: All plans showed good target coverage while OARs met the dose constraint guidelines. Vastly different implant and planning styles were reflected on conformity index (entire dose matrix V100/PTV volume, physician A implants: 1.27±0.14, physician B: 1.47±0.17) and PTV V150/PTV volume ratio (physician A: 0.34±0.09, physician B: 0.24±0.07). The quadratic model provided a better fit for the curved relationship between normalized implant strength and total V100 (or PTV volume) than a simple linear function. Unlike the normalized implant strength versus PTV volume nomogram which differed between physicians, a unique quadratic model based nomogram (Sk*t)/D=−0.0008V2+0.0542V+1.1185 (R{sup 2}=0.9977) described the dependence of normalized implant strength on total V100 over all the patients from both physicians despite two different implant and planning philosophies. Normalized implant strength - total V100 model also generated less deviant points distorting the smoothed ones with a significantly higher correlation. Conclusion: A simple and universal, excel-based nomogram was created as an independent calculation tool for HDR prostate brachytherapy. Unlike similar attempts, our nomogram is insensitive to implant

Novel high resolution 125I brachytherapy source dosimetry using Ge-doped optical fibres

International Nuclear Information System (INIS)

Issa, Fatma; Hugtenburg, Richard P.; Nisbet, Andrew; Bradley, David A.

2013-01-01

The steep dose gradients close to brachytherapy sources limit the ability to obtain accurate measurements of dose. Here we use a novel high spatial resolution dosimeter to measure dose around a 125 I source and compare against simulations. Ge-doped optical fibres, used as thermoluminescent dosimeters, offer sub-mm spatial resolution, linear response from 10 cGy to >1 kGy and dose-rate independence. For a 125 I brachytherapy seed in a PMMA phantom, doses were obtained for source-dosimeter separations from 0.1 cm up to several cm, supported by EGSnrc/DOSRZznrc Monte Carlo simulations and treatment planning system data. The measurements agree with simulations to within 2.3%±0.3% along the transverse and perpendicular axes and within 3.0%±0.5% for measurements investigating anisotropy in angular dose distribution. Measured and Veriseed™ brachytherapy treatment planning system (TPS) values agreed to within 2.7%±0.5%. Ge-doped optical fibre dosimeters allow detailed dose mapping around brachytherapy sources, not least in situations of high dose gradient. - Highlights: • We evaluate fall-off in dose for distances from an 125 I source of 1 mm to 60 mm. • The TL of optical fibres accommodate high dose gradients and doses that reduce by a factor of 10 3 across the range of separations. • We verify measured values using DOSRZnrc Monte Carlo code simulations and the Variseed™ Treatment Planning System. • Measured radial and angular dose are obtained with ≤3% uncertainty

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-06-15

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

Endorectal high dose rate brachytherapy quality assurance

International Nuclear Information System (INIS)

Devic, S.; Vuong, T.; Evans, M.; Podgorsak, E.

2008-01-01

We describe our quality assurance method for preoperative high dose rate (HDR) brachytherapy of endorectal tumours. Reproduction of the treatment planning dose distribution on a daily basis is crucial for treatment success. Due to the cylindrical symmetry, two types of adjustments are necessary: applicator rotation and dose distribution shift along the applicator axis. (author)

MO-A-BRB-02: Considerations and Issues in Electronic Charting for Brachytherapy

International Nuclear Information System (INIS)

Richardson, S.

2015-01-01

The process of converting to an electronic chart for radiation therapy can be daunting. It requires a dedicated committee to first research and choose appropriate software, to review the entire documentation policy and flow of the clinic, to convert this system to electronic form or if necessary, redesign the system to more easily conform to the electronic process. Those making the conversion and those who already use electronic charting would benefit from the shared experience of those who have been through the process in the past. Therefore TG262 was convened to provide guidance on electronic charting for external beam radiation therapy and brachytherapy. This course will present the results of an internal survey of task group members on EMR practices in External Beam Radiation Therapy as well as discuss important issues in EMR development and structure for both EBRT and brachytherapy. Learning Objectives: Be familiarized with common practices and pitfalls in development and maintenance of an electronic chart in Radiation Oncology Be familiarized with important issues related to electronic charting in External Beam Radiation Therapy Be familiarized with important issues related to electronic charting in Brachytherapy

A study of brachytherapy for intraocular tumor

International Nuclear Information System (INIS)

Ji, Yung Hoon; Lee, Dong Han; Ko, Kyung Hwan; Lee, Tae Won; Lee, Sung Koo; Choi, Moon Sik

1994-12-01

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

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...

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

Intensity-Modulated Radiotherapy Causes Fewer Side Effects than Three-Dimensional Conformal Radiotherapy When Used in Combination With Brachytherapy for the Treatment of Prostate Cancer

International Nuclear Information System (INIS)

Forsythe, Kevin; Blacksburg, Seth; Stone, Nelson; Stock, Richard G.

2012-01-01

Purpose: To measure the benefits of intensity-modulated radiotherapy (IMRT) compared with three-dimensional conformal radiotherapy (3D-CRT) when used in combination with brachytherapy for the treatment of prostate cancer. Methods and Materials: We conducted a retrospective review of all patients with localized prostate cancer who received external-beam radiotherapy (EBRT) in combination with brachytherapy with at least 1 year follow-up (n = 812). Combination therapy consisted of 103 Pd or 125 I implant, followed by a course of EBRT. From 1993 to March 2003 521 patients were treated with 3D-CRT, and from April 2003 to March 2009 291 patients were treated with IMRT. Urinary symptoms were prospectively measured with the International Prostate Symptom Score questionnaire with a single quality of life (QOL) question; rectal bleeding was assessed per the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Schema. The Pearson χ 2 test was used to compare toxicities experienced by patients who were treated with either IMRT or 3D-CRT. Logistic regression analyses were also performed to rule out possible confounding factors. Results: Within the first 3 months after treatment, patients treated with 3D-CRT scored their urinary symptoms as follows: 19% mild, 44% moderate, and 37% severe; patients treated with IMRT scored their urinary symptoms as follows: 36% mild, 47% moderate, and 17% severe (p < 0.001). The 3D-CRT patients rated their QOL as follows: 35% positive, 20% neutral, and 45% negative; IMRT patients rated their QOL as follows: 51% positive, 18% neutral, and 31% negative (p < 0.001). After 1 year of follow-up there was no longer any difference in urinary morbidity between the two groups. Logistic regression confirmed the differences in International Prostate Symptom Score and QOL in the acute setting (p < 0.001 for both). Grade ≥2 rectal bleeding was reported by 11% of 3D-CRT patients and 7

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

3D Conformal radiotherapy for gastric cancer-results of a comparative planning study

International Nuclear Information System (INIS)

Leong, Trevor; Willis, David; Joon, Daryl Lim; Condron, Sara; Hui, Andrew; Ngan, Samuel Y.K.

2005-01-01

Background and purpose: Many radiation oncologists are reluctant to use anteroposterior-posteroanterior (AP-PA) field arrangements when treating gastric cancer with adjuvant postoperative radiotherapy due to concerns about normal tissue toxicity, particularly in relation to the kidneys and spinal cord. In this report, we describe a multiple-field conformal radiotherapy technique, and compare this technique to the more commonly used AP-PA technique that was used in the recently reported Intergroup study (INT0116). Materials and methods: Fifteen patients with stages II-IV adenocarcinoma of the stomach were treated with adjuvant postoperative chemoradiotherapy using a standardised 3D conformal radiotherapy technique that consisted of a 'split-field', mono-isocentric arrangement employing 6 radiation fields. For each patient, a second radiotherapy treatment plan was generated utilising AP-PA fields. The two techniques were then compared for target volume coverage and dose to normal tissues using dose volume histogram (DVH) analysis. Results: The conformal technique provides more adequate coverage of the target volume with 99% of the planning target volume (PTV) receiving 95% of the prescribed dose, compared to 93% using AP-PA fields. Comparative DVHs for the right kidney, left kidney and spinal cord demonstrate lower radiation doses using the conformal technique, and although the liver dose is higher, it is still well below liver tolerance. Conclusions: 3D conformal radiotherapy produces superior dose distributions and reduced radiation doses to the kidneys and spinal cord compared to AP-PA techniques, with the potential to reduce treatment toxicity

Australian high-dose-rate brachytherapy protocols for gynaecological malignancy

International Nuclear Information System (INIS)

MacLeod, C.; Dally, M.; Stevens, M.; Thornton, D.; Carruthers, S.; Jeal, P.

2001-01-01

There is no consensus over the optimal dose fractionation schedules for high-dose-rate (HDR) brachytherapy used for gynaecological malignancy. In Australian public hospital departments of radiation oncology, HDR brachytherapy for gynaecological cancer is being more commonly used. A survey of public departments that are using this technology, or that plan to introduce this technology, was performed. Their current protocols are presented. In general, protocols are similar biologically; however, the practical aspects such as the number of fractions given do vary and may reflect resource restrictions or, alternatively, differences in interpretations of the literature and of the best protocols by clinicians. Copyright (2001) Blackwell Science Pty Ltd

A study of Brachytherapy for Intraocular Tumor

International Nuclear Information System (INIS)

Ji, Kwang Soo; Yoo, Dae Hyun; Lee, Sung Goo; Kim, Jae Hu; Ji, Young Hun

1996-01-01

The eye enucleation or external-beam radiation therapy that has been commonly used for the treatment of intraocular tumor have demerits of visual loss and in deficiency of effective tumor dose. Recently, brachytherapy using the plaques containing radioisotope-now treatment method that decrease the demerits of the above mentioned treatment methods and increase the treatment effect-is introduced and performed in the countries, Our purpose of this research is to design suitable shape of plaque for the ophthalmic brachytherapy, and to measure absorbed doses of Ir-192 ophthalmic plaque and thereby calculate the exact radiation dose of tumor and it's adjacent normal tissue. In order to brachytherapy for intraocular tumor, 1. to determine the eye model and selected suitable radioisotope 2. to design the suitable shape of plaque 3. to measure transmission factor and dose distribution for custom made plaques 4. to compare with the these data and results of computer dose calculation models. The result were as followed. 1. Eye model was determined as a 25 mm diameter sphere, Ir-192 was considered the most appropriate as radioisotope for brachytherapy, because of the size, half, energy and availability. 2. Considering the biological response with human tissue and protection of exposed dose, we made the plaques with gold, of which size were 15 mm, 17 mm and 20 mm in diameter, and 1.5 mm in thickness. 3. Transmission factor of plaques are all 0.71 with TLD and film dosimetry at the surface of plaques and 0.45, 0.49 at 1.5 mm distance of surface, respectively. 4. As compared the measured data for the plaque with Ir-192 seeds to results of computer dose calculation model by Gary Luxton et al. and CAP-PLAN (Radiation Treatment Planning System), absorbed doses are within ±10% and distance deviations are within 0.4 mm Maximum error is -11.3% and 0.8 mm, respectively. As a result of it, we can treat the intraocular tumor more effectively by using custom made gold plaque and Ir-192

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.

Radioactive seed immobilization techniques for interstitial brachytherapy

International Nuclear Information System (INIS)

Yan, K.; Podder, T.; Buzurovic, I.; Hu, Y.; Dicker, A.; Valicenti, R.; Yu, Y.; Messing, E.; Rubens, D.; Sarkar, N.; Ng, W.

2008-01-01

In prostate brachytherapy, seeds can detach from their deposited sites and move locally in the pelvis or migrate to distant sites including the pulmonary and cardiac regions. Undesirable consequences of seed migration include inadequate dose coverage of the prostate and tissue irradiation effects at the site of migration. Thus, it is clinically important to develop seed immobilization techniques. We first analyze the possible causes for seed movement, and propose three potential techniques for seed immobilization: (1) surgical glue, (2) laser coagulation and (3) diathermy coagulation. The feasibility of each method is explored. Experiments were carried out using fresh bovine livers to investigate the efficacy of seed immobilization using surgical glue. Results have shown that the surgical glue can effectively immobilize the seeds. Evaluation of the radiation dose distribution revealed that the non-immobilized seed movement would change the planned isodose distribution considerably; while by using surgical glue method to immobilize the seeds, the changes were negligible. Prostate brachytherapy seed immobilization is necessary and three alternative mechanisms are promising for addressing this issue. Experiments for exploring the efficacy of the other two proposed methods are ongoing. Devices compatible with the brachytherapy procedure will be designed in future. (orig.)

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

Science.gov (United States)

Shi, Chengyu; Guo, Bingqi; Cheng, Chih-Yao; Eng, Tony; Papanikolaou, Nikos

2010-09-01

A low-energy electronic brachytherapy source (EBS), the model S700 Axxent™ x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V100 reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as compared to 95

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-09-21

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

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

International Nuclear Information System (INIS)

Shi Chengyu; Guo Bingqi; Eng, Tony; Papanikolaou, Nikos; Cheng, Chih-Yao

2010-01-01

A low-energy electronic brachytherapy source (EBS), the model S700 Axxent(TM) x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V 100 reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as compared to 95

Intravascular brachytherapy for peripheral vascular disease

Directory of Open Access Journals (Sweden)

Hagen, Anja

2008-09-01

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

Patterns of failure after use of 18F-FDG PET/CT in integration of extended-field chemo-IMRT and 3D-brachytherapy plannings for advanced cervical cancers with extensive lymph node metastases

International Nuclear Information System (INIS)

Chung, Yih-Lin; Horng, Cheng-Fang; Lee, Pei-Ing; Chen, Fong-Lin

2016-01-01

The study is to evaluate the patterns of failure, toxicities and long-term outcomes of aggressive treatment using 18 F-FDG PET/CT-guided chemoradiation plannings for advanced cervical cancer with extensive nodal extent that has been regarded as a systemic disease. We retrospectively reviewed 72 consecutive patients with 18 F-FDG PET/CT-detected widespread pelvic, para-aortic and/or supraclavicular lymph nodes treated with curative-intent PET-guided cisplatin-based extended-field dose-escalating intensity-modulated radiotherapy (IMRT) and adaptive high-dose-rate intracavitary 3D-brachytherapy between 2002 and 2010. The failure sites were specifically localized by comparing recurrences on fusion of post-therapy recurrent 18 F-FDG PET/CT scans to the initial PET-guided radiation plannings for IMRT and brachytherapy. The median follow-up time for the 72 patients was 66 months (range, 3–142 months). The 5-year disease-free survival rate calculated by the Kaplan-Meier method for the patients with extensive N1 disease with the uppermost PET-positive pelvic-only nodes (26 patients), and the patients with M1 disease with the uppermost PET-positive para-aortic (31 patients) or supraclavicular (15 patients) nodes was 78.5 %, and 41.8–50 %, respectively (N1 vs. M1, p = 0.0465). Eight (11.1 %), 18 (25.0 %), and 3 (4.2 %) of the patients developed in-field recurrence, out-of-field and/or distant metastasis, and combined failure, respectively. The 6 (8.3 %) local failures around the uterine cervix were all at the junction between IMRT and brachytherapy in the parametrium. The rate of late grade 3/4 bladder and bowel toxicities was 4.2 and 9.7 %, respectively. When compared to conventional pelvic chemoradiation/2D-brachytherapy during 1990–2001, the adoption of 18 F-FDG PET-guided extended-field dose-escalating chemoradiation plannings in IMRT and 3D-brachytherapy after 2002 appeared to provide higher disease-free and overall survival rates with acceptable toxicities in

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)

Brachytherapy optimization using radiobiological-based planning for high dose rate and permanent implants for prostate cancer treatment

Science.gov (United States)

Seeley, Kaelyn; Cunha, J. Adam; Hong, Tae Min

2017-01-01

We discuss an improvement in brachytherapy--a prostate cancer treatment method that directly places radioactive seeds inside target cancerous regions--by optimizing the current standard for delivering dose. Currently, the seeds' spatiotemporal placement is determined by optimizing the dose based on a set of physical, user-defined constraints. One particular approach is the ``inverse planning'' algorithms that allow for tightly fit isodose lines around the target volumes in order to reduce dose to the patient's organs at risk. However, these dose distributions are typically computed assuming the same biological response to radiation for different types of tissues. In our work, we consider radiobiological parameters to account for the differences in the individual sensitivities and responses to radiation for tissues surrounding the target. Among the benefits are a more accurate toxicity rate and more coverage to target regions for planning high-dose-rate treatments as well as permanent implants.

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...

A study of optimization techniques in HDR brachytherapy for the prostate

Science.gov (United States)

Pokharel, Ghana Shyam

Several studies carried out thus far are in favor of dose escalation to the prostate gland to have better local control of the disease. But optimal way of delivery of higher doses of radiation therapy to the prostate without hurting neighboring critical structures is still debatable. In this study, we proposed that real time high dose rate (HDR) brachytherapy with highly efficient and effective optimization could be an alternative means of precise delivery of such higher doses. This approach of delivery eliminates the critical issues such as treatment setup uncertainties and target localization as in external beam radiation therapy. Likewise, dosimetry in HDR brachytherapy is not influenced by organ edema and potential source migration as in permanent interstitial implants. Moreover, the recent report of radiobiological parameters further strengthen the argument of using hypofractionated HDR brachytherapy for the management of prostate cancer. Firstly, we studied the essential features and requirements of real time HDR brachytherapy treatment planning system. Automating catheter reconstruction with fast editing tools, fast yet accurate dose engine, robust and fast optimization and evaluation engine are some of the essential requirements for such procedures. Moreover, in most of the cases we performed, treatment plan optimization took significant amount of time of overall procedure. So, making treatment plan optimization automatic or semi-automatic with sufficient speed and accuracy was the goal of the remaining part of the project. Secondly, we studied the role of optimization function and constraints in overall quality of optimized plan. We have studied the gradient based deterministic algorithm with dose volume histogram (DVH) and more conventional variance based objective functions for optimization. In this optimization strategy, the relative weight of particular objective in aggregate objective function signifies its importance with respect to other objectives

Reirradiation of nasopharyngeal carcinoma with intracavitary mold brachytherapy: an effective means of local salvage

International Nuclear Information System (INIS)

Law, Stephen C.K.; Lam, W.-K.; Ng, M.-F.; Au, S.-K.; Mak, W.-T.; Lau, W.-H.

2002-01-01

Purpose: To assess the role of intracavitary mold brachytherapy in salvaging local failure of nasopharyngeal carcinoma (NPC). Methods and Materials: The outcomes of 118 consecutive NPC patients with local failure treated with mold brachytherapy between 1989 and 1996 were retrospectively reviewed. Eleven patients received additional external radiotherapy. Results: All molds were tailor-made, and the whole procedure was performed under local anesthesia. Pharyngeal recess dissection was routinely performed to allow direct contact of the radioactive source with the pharyngeal recess, a common site of local failure. Initially, the molds were preloaded with 192 Ir wires, but since 1992, the sources have been manually afterloaded; the mold has also been redesigned for better conformity, ease of insertion, and radiation safety. Using brachytherapy alone, 50-55 Gy was given for recurrence in 4-7 days; for persistence, 40 Gy was administered. The overall complete remission rate was 97%. The rates of 5-year local control, relapse-free survival, disease-specific survival, overall survival, and major complication were 85%, 68.3%, 74.8%, 61.3%, and 46.9%, respectively. Major complications included nasopharyngeal necrosis with headache, necrosis of cervical vertebrae with atlantoaxial instability, temporal lobe necrosis, and palsy of the cranial nerves. The afterloaded mold was as effective as the preloaded version, but with fewer complications. Conclusions: Intracavitary mold brachytherapy was effective in salvaging NPC with early-stage local persistence or first recurrence

MRI-guided brachytherapy for cancer of the oesophagus

International Nuclear Information System (INIS)

Aydin, H.; Bachmann, G.; Lieven, H. von; Sens, M.

1993-01-01

A method of brachytherapy treatment planning using MRI is presented. In 13 patients with inoperable squamous cell cancer of the thoracic oesophagus an intraluminal afterloading boost with MRI assistance was performed. A new type of flexible catheter was filled with 1/100 diluted Gd-DTPA and introduced into the oesophagus before performing MRI in the sagittal, coronal and transverse planes. One sagittal or coronal picture which showed the catheter tip and the residual cancer was magnified to ''life size''. The position of the catheter was corrected if necessary and the treatment volume decided. The contrast medium was then aspirated out of the catheter and a thinner afterloading catheter pushed into the outer catheter. The patient was moved immediately to the afterloading room and received the first dose of boost irradiation. This method allows much more precise brachytherapy planning since it shows the cancer and the catheter together. It is superior to localising the cancer with a barium swallow or endoscopy because MRI visualises the whole extent of the residual cancer, which can then be covered with the necessary dose. (orig.)

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)

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

Conventional and conformal technique of external beam radiotherapy in locally advanced cervical cancer: Dose distribution, tumor response, and side effects

Science.gov (United States)

Mutrikah, N.; Winarno, H.; Amalia, T.; Djakaria, M.

2017-08-01

The objective of this study was to compare conventional and conformal techniques of external beam radiotherapy (EBRT) in terms of the dose distribution, tumor response, and side effects in the treatment of locally advanced cervical cancer patients. A retrospective cohort study was conducted on cervical cancer patients who underwent EBRT before brachytherapy in the Radiotherapy Department of Cipto Mangunkusumo Hospital. The prescribed dose distribution, tumor response, and acute side effects of EBRT using conventional and conformal techniques were investigated. In total, 51 patients who underwent EBRT using conventional techniques (25 cases using Cobalt-60 and 26 cases using a linear accelerator (LINAC)) and 29 patients who underwent EBRT using conformal techniques were included in the study. The distribution of the prescribed dose in the target had an impact on the patient’s final response to EBRT. The complete response rate of patients to conformal techniques was significantly greater (58%) than that of patients to conventional techniques (42%). No severe acute local side effects were seen in any of the patients (Radiation Therapy Oncology Group (RTOG) grades 3-4). The distribution of the dose and volume to the gastrointestinal tract affected the proportion of mild acute side effects (RTOG grades 1-2). The urinary bladder was significantly greater using conventional techniques (Cobalt-60/LINAC) than using conformal techniques at 72% and 78% compared to 28% and 22%, respectively. The use of conformal techniques in pelvic radiation therapy is suggested in radiotherapy centers with CT simulators and 3D Radiotherapy Treatment Planning Systems (RTPSs) to decrease some uncertainties in radiotherapy planning. The use of AP/PA pelvic radiation techniques with Cobalt-60 should be limited in body thicknesses equal to or less than 18 cm. When using conformal techniques, delineation should be applied in the small bowel, as it is considered a critical organ according to RTOG

Reduced dose to urethra and rectum with the use of variable needle spacing in prostate brachytherapy: a potential role for robotic technology.

Science.gov (United States)

Vyas, Shilpa; Le, Yi; Zhang, Zhe; Armour, Woody; Song, Daniel Y

2015-08-01

Several robotic delivery systems for prostate brachytherapy are under development or in pre-clinical testing. One of the features of robotic brachytherapy is the ability to vary spacing of needles at non-fixed intervals. This feature may play an important role in prostate brachytherapy, which is traditionally template-based with fixed needle spacing of 0.5 cm. We sought to quantify potential reductions in the dose to urethra and rectum by utilizing variable needle spacing, as compared to fixed needle spacing. Transrectal ultrasound images from 10 patients were used by 3 experienced planners to create 120 treatment plans. Each planner created 4 plan variations per patient with respect to needle positions: (125)I fixed spacing, (125)I variable spacing, (103)Pd fixed spacing, and (103)Pd variable spacing. The primary planning objective was to achieve a prostate V100 of 100% while minimizing dose to urethra and rectum. All plans met the objective of achieving prostate V100 of 100%. Combined results for all plans show statistically significant improvements in all assessed dosimetric variables for urethra (Umax, Umean, D30, D5) and rectum (Rmax, Rmean, RV100) when using variable spacing. The dose reductions for mean and maximum urethra dose using variable spacing had p values of 0.011 and 0.024 with (103)Pd, and 0.007 and 0.029 with (125)I plans. Similarly dose reductions for mean and maximum rectal dose using variable spacing had p values of 0.007 and 0.052 with (103)Pd, and 0.012 and 0.037 with (125)I plans. The variable needle spacing achievable by the use of robotics in prostate brachytherapy allows for reductions in both urethral and rectal planned doses while maintaining prostate dose coverage. Such dosimetric advantages have the potential in translating to significant clinical benefits with the use of robotic brachytherapy.

Radiological protection of patients in brachytherapy

International Nuclear Information System (INIS)

Sacc, Ricardo; Herrero, Flavia

2008-01-01

Full text: The prefix 'brachy' means short-range, so brachytherapy is the administration of radiation therapy using small radioactive sources in the form of needles, tubes, wires or seeds, which are placed within the tumor -interstitial form- or very near of it, superficially or in an endo-cavity form. This technique, which was limited by the size of the primary tumor, has the advantage, that the radiation, can be adjusted to the size and shape of the tumor volume and the radioisotope used, - short range -, is selected with the criteria of getting the dose in the organs at risk, as low as possible, making what it is known as conformal radiotherapy. Radioactive sources may be permanent or temporary implants. The application of radioactive material, can be manually or automatically. In the first case, a major breakthrough from the radioprotection point of view, was the use of afterloading devices, methodology highly recommended to reduce the radiation exposure to staff. With the development of technology, remotely controlled afterloading devices were introduced, which in addition to complying with the above requirement, allow the source to move in different positions along catheters housed in one or more channels, making therapeutic brachytherapy treatments in tumor volumes possible, that due to its length, decades ago would have been an unthinkable deal. In all cases, sources, which may vary from the 3 mm in length, 125 Iodine or 198 Gold seeds, to extensive wires of 192 Iridium, are encapsulated for two main purposes: preventing leakage of radioactive material and absorption of unwanted radiation, alpha and beta, produced by the radioactive decay. Consequently, it should be highly unlikely that the radioactive material, could be lost or located in the patient, in a different place of the one that was planned. However, history shows us the opposite. Its is known the kind of deterministic effect that radiation is going to produce in the tumor, where the severity of

Impact of systematic errors on DVH parameters of different OAR and target volumes in Intracavitary Brachytherapy (ICBT)

International Nuclear Information System (INIS)

Mourya, Ankur; Singh, Gaganpreet; Kumar, Vivek; Oinam, Arun S.

2016-01-01

Aim of this study is to analyze the impact of systematic errors on DVH parameters of different OAR and Target volumes in intracavitary brachytherapy (ICBT). To quantify the changes in dose-volume histogram parameters due to systematic errors in applicator reconstruction of brachytherapy planning, known errors in catheter reconstructions have to be introduced in applicator coordinate system

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

Directory of Open Access Journals (Sweden)

Barlanka Ravikumar

2012-01-01

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

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)

Conformational episcleral brachytherapy in ocular tumors

International Nuclear Information System (INIS)

Goset, Karen; Barriga, Hernan; Guevara, Juan; Zelada, Gabriel; Badinez, Leonardo; Gonzalez, German

2000-01-01

Brachytherapy with an episcleral plate is an alternative treatment for choroid melanomas and retinoblastomas that allows the sight to be saved. The most common techniques use a metal applicator with beta or Co-60 transmitters, which have a standard geometry, require surgical installation of the active devices and do not allow optimized dosimetry. In 1997, the Clinica Alemana in Santiago, Chile, developed a new device based on the one described by J.P. Gerard (1988), with plastic material, personalized and with delayed charge. Three cases have been treated. Two retinoblastomas: 1) Primary treatment in unilateral Rb, R.E. group II in a 9 month old boy, 2) External post radiotherapy rescue in oculus ultimus by bilateral Rb in a 10 year old girl, and 3) Choroid melanoma T3N0M0 in a 77 year old woman. A personalized applicator was prepared in each case depending on the size and location of the tumor. The distribution of the vector catheters was designed following the Paris system standards. The applicator was inserted in the operating room, under general anesthesia by a team of trained ophthalmologists. An X-ray and helichoidal simulation scan were taken with fictitious sources. Previsional dosimetry was undertaken, with evaluation of the dosage to the tumor apex, crystalline lens, sclera and optic nerve. Prolonged activation with low level dosage Ir-192 wires was performed in a protected room. When the programmed dosage was completed, the sources and then the inactive applicator were removed. Dosage: A 40 Gy dose was applied in the retinoblastoma to the tumor apex and 60 Gy to the melanoma, over a 2 to 3 day period. Tolerance was excellent, there were no incidents or acute complications. The retinoblastomas fully regressed in 1 to 2 weeks, with no local relapse or after affects after 2, 4 and 6 months of follow-up. The 3 patients have retained their sight. The development of this technique is feasible and with enough resources, relatively easy to implement. It has

SU-C-202-02: A Comprehensive Evaluation of Adaptive Daily Planning for Cervical Cancer HDR Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Meerschaert, R; Paul, A; Zhuang, L [Department of Oncology, Radiation Oncology Division, Wayne State University School of Medicine, Detroit, MI (United States); Nalichowski, A [Department of Oncology, Radiation Oncology Division, Karmanos Cancer Institute, Detroit, MI (United States); Burmeister, J; Miller, A [Department of Oncology, Radiation Oncology Division, Wayne State University School of Medicine, Detroit, MI (United States); Department of Oncology, Radiation Oncology Division, Karmanos Cancer Institute, Detroit, MI (United States)

2016-06-15

Purpose: To evaluate adaptive daily planning for cervical cancer patients who underwent high-dose-rate intra-cavitary brachytherapy (HDR-ICBT). Methods: This study included 22 cervical cancer patients who underwent 5 fractions of HDR ICBT. Regions of interest (ROIs) including high-risk clinical tumor volume (HR-CTV) and organs-at-risk (OARs) were manually contoured on daily CT images. All patients were treated with adaptive daily plans, which involved ROI delineation and dose optimization at each treatment fraction. Single treatment plans were retrospectively generated by applying the first treatment fraction’s dwell times adjusted for decay and dwell positions of the applicator to subsequent treatment fractions. Various existing similarity metrics were calculated for the ROIs to quantify interfractional organ variations. A novel similarity score (JRARM) was established, which combined both volumetric overlap metrics (DSC, JSC, and RVD) and distance metrics (ASD, MSD, and RMSD). Linear regression was performed to determine a relationship between inter-fractional organ variations of various similarity metrics and D2cc variations from both plans. Wilcoxon Signed Rank Tests were used to assess adaptive daily plans and single plans by comparing EQD2 D2cc (α/β=3) for OARs. Results: For inter-fractional organ variations, the sigmoid demonstrated the greatest variations based on the JRARM and DSC similarity metrics. Comparisons between paired ROIs showed differences in JRARM scores and DSCs at each treatment fraction. RVD, MSD, and RMSD were found to be significantly correlated to D2cc variations for bladder and sigmoid. The comparison between plans found that adaptive daily planning provided lower EQD2 D2cc of OARs than single planning, specifically for the sigmoid (p=0.015). Conclusion: Substantial inter-fractional organ motion can occur during HDR-BT, which may significantly affect D2cc of OARs. Adaptive daily planning provides improved dose sparing for OARs

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-06-01

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

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-06-15

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

Multihelix rotating shield brachytherapy for cervical cancer

Energy Technology Data Exchange (ETDEWEB)

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

2015-11-15

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

A dosimetric selectivity intercomparison of HDR brachytherapy, IMRT and helical tomotherapy in prostate cancer radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Hermesse, Johanne; Biver, Sylvie; Jansen, Nicolas; Coucke, Philippe [Dept. of Radiation Oncology, Liege Univ. Hospital (Belgium); Lenaerts, Eric [Dept. of Medical Physics, Liege Univ. Hospital (Belgium); De Patoul, Nathalie; Vynckier, Stefaan [Dept. of Medical Physics, St Luc Univ. Hospital, Brussels (Belgium); Scalliet, Pierre [Dept. of Radiation Oncology, St Luc Univ. Hospital, Brussels (Belgium); Nickers, Philippe [Dept. of Radiation Oncology, Oscar Lambret Center, Lille (France)

2009-11-15

Background and purpose: dose escalation in order to improve the biochemical control in prostate cancer requires the application of irradiation techniques with high conformality. The dosimetric selectivity of three radiation modalities is compared: high-dose-rate brachytherapy (HDR-BT), intensity-modulated radiation radiotherapy (IMRT), and helical tomotherapy (HT). Patients and methods: ten patients with prostate adenocarcinoma treated by a 10-Gy HDR-BT boost after external-beam radiotherapy were investigated. For each patient, HDR-BT, IMRT and HT theoretical treatment plans were realized using common contour sets. A 10-Gy dose was prescribed to the planning target volume (PTV). The PTVs and critical organs' dose-volume histograms obtained were compared using Student's t-test. Results: HDR-BT delivers spontaneously higher mean doses to the PTV with smaller cold spots compared to IMRT and HT. 33% of the rectal volume received a mean HDR-BT dose of 3.86 {+-} 0.3 Gy in comparison with a mean IMRT dose of 6.57 {+-} 0.68 Gy and a mean HT dose of 5.58 {+-} 0.71 Gy (p < 0.0001). HDR-BT also enables to better spare the bladder. The hot spots inside the urethra are greater with HDR-BT. The volume of healthy tissue receiving 10% of the prescribed dose is reduced at least by a factor of 8 with HDR-BT (p < 0.0001). Conclusion: HDR-BT offers better conformality in comparison with HT and IMRT and reduces the volume of healthy tissue receiving a low dose. (orig.)

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.

40 CFR 93.154 - Conformity analysis.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Conformity analysis. 93.154 Section 93...) DETERMINING CONFORMITY OF FEDERAL ACTIONS TO STATE OR FEDERAL IMPLEMENTATION PLANS Determining Conformity of General Federal Actions to State or Federal Implementation Plans § 93.154 Conformity analysis. Any Federal...

HDR brachytherapy in carcinoma of cervix: initial experience at AWARE hospitals

International Nuclear Information System (INIS)

Rajendran, M.; Reddy, K.D.; Reddy, R.M.; Reddy, J.M.; Reddy, B.V.N.; Kiran Kumar; Gopi, S.; Dharaniraj; Janardhanan

2002-01-01

High dose rate (HDR) brachytherapy is well established in the management of gynaecological malignancies. A report on the initial results of one and half year experience with a consistent dose/fractionation schedule and procedure of planning with delivery of treatment schedule is presented

Brachytherapy reconstruction using orthogonal scout views from the CT

International Nuclear Information System (INIS)

Perez, J.; Lliso, F.; Carmona, V.; Bea, J.; Tormo, A.; Petschen, I.

1996-01-01

Introduction: CT assisted brachytherapy planning is demonstrating to have great advantages as external RT planning does. One of the problems we have found in this approach with the conventional gynecological Fletcher applicators is the high amount of artefacts (ovoids with rectal and vessical protections) in the CT slice. We have introduced a reconstruction method based on scout views in order to avoid this problem, allowing us to perform brachytherapy reconstruction completely CT assisted. We use a virtual simulation chain by General Electric Medical Systems. Method and discussion: Two orthogonal scout views (0 and 90 tube positions) are performed. The reconstruction method takes into account the virtual position of the focus and the fact that there is only divergence in the transverse plane. Algorithms developed for sources as well as for reference points localisation (A, B, lymphatic Fletcher trapezoid, pelvic wall, etc.) are presented. This method has the following practical advantages: the porte-cassette is not necessary, the image quality can be improved (it is very helpful in pelvic lateral views that are critical in conventional radiographs), the total time to get the data is smaller than for conventional radiographs (reduction of patient motion effects) and problems that appear in CT-slice based reconstruction in the case of strongly curved intrauterine applicators are avoided. Even though the resolution is smaller than in conventional radiographs it is good enough for brachytherapy. Regarding the CT planning this method presents the interesting feature that the co-ordinate system is the same for the reconstruction process that for the CT-slices set. As the application can be reconstructed from scout views and the doses can be evaluated on CT slices it is easier to correlate the dose values obtained for the traditional points with those provided by the CT information

Sci-Thur PM – Brachytherapy 04: Commissioning and Implementation of a Cobalt-60 High Dose Rate Brachytherapy Source

Energy Technology Data Exchange (ETDEWEB)

Dysart, Jonathan [Horizon Health Network (Canada)

2016-08-15

An Eckert & Ziegler Bebig Co0.A86 cobalt 60 high dose rate (HDR) brachytherapy source was commissioned for clinical use. Long-lived Co-60 HDR sources offer potential logistical and economic advantages over Ir-192 sources, and should be considered for low to medium workload brachytherapy departments where modest increases in treatment times are not a factor. In optimized plans, the Co-60 source provides a similar dose distribution to Ir-192 despite the difference in radiation energy. By switching to Co-60, source exchange frequency can be reduced by a factor of 20, resulting in overall financial savings of more than 50% compared to Ir-192 sources. In addition, a reduction in Physicist QA workload of roughly 200 hours over the 5 year life of the Co-60 source is also expected. These benefits should be considered against the modest increases in average treatment time compared to those of Ir-192 sources, as well as the centre-specific needs for operating room shielding modification.

A dose homogeneity and conformity evaluation between ViewRay and pinnacle-based linear accelerator IMRT treatment plans

Directory of Open Access Journals (Sweden)

Daniel L Saenz

2014-01-01

Full Text Available ViewRay, a novel technology providing soft-tissue imaging during radiotherapy is investigated for treatment planning capabilities assessing treatment plan dose homogeneity and conformity compared with linear accelerator plans. ViewRay offers both adaptive radiotherapy and image guidance. The combination of cobalt-60 (Co-60 with 0.35 Tesla magnetic resonance imaging (MRI allows for magnetic resonance (MR-guided intensity-modulated radiation therapy (IMRT delivery with multiple beams. This study investigated head and neck, lung, and prostate treatment plans to understand what is possible on ViewRay to narrow focus toward sites with optimal dosimetry. The goal is not to provide a rigorous assessment of planning capabilities, but rather a first order demonstration of ViewRay planning abilities. Images, structure sets, points, and dose from treatment plans created in Pinnacle for patients in our clinic were imported into ViewRay. The same objectives were used to assess plan quality and all critical structures were treated as similarly as possible. Homogeneity index (HI, conformity index (CI, and volume receiving <20% of prescription dose (DRx were calculated to assess the plans. The 95% confidence intervals were recorded for all measurements and presented with the associated bars in graphs. The homogeneity index (D5/D95 had a 1-5% inhomogeneity increase for head and neck, 3-8% for lung, and 4-16% for prostate. CI revealed a modest conformity increase for lung. The volume receiving 20% of the prescription dose increased 2-8% for head and neck and up to 4% for lung and prostate. Overall, for head and neck Co-60 ViewRay treatments planned with its Monte Carlo treatment planning software were comparable with 6 MV plans computed with convolution superposition algorithm on Pinnacle treatment planning system.

A dose homogeneity and conformity evaluation between ViewRay and pinnacle-based linear accelerator IMRT treatment plans

International Nuclear Information System (INIS)

Saenz, Daniel L.; Paliwal, Bhudatt R.; Bayouth, John E.

2014-01-01

ViewRay, a novel technology providing soft-tissue imaging during radiotherapy is investigated for treatment planning capabilities assessing treatment plan dose homogeneity and conformity compared with linear accelerator plans. ViewRay offers both adaptive radiotherapy and image guidance. The combination of cobalt-60 ( 60 Co) with 0.35 Tesla magnetic resonance imaging (MRI) allows for magnetic resonance (MR)-guided intensity-modulated radiation therapy (IMRT) delivery with multiple beams. This study investigated head and neck, lung, and prostate treatment plans to understand what is possible on ViewRay to narrow focus toward sites with optimal dosimetry. The goal is not to provide a rigorous assessment of planning capabilities, but rather a first order demonstration of ViewRay planning abilities. Images, structure sets, points, and dose from treatment plans created in Pinnacle for patients in our clinic were imported into ViewRay. The same objectives were used to assess plan quality and all critical structures were treated as similarly as possible. Homogeneity index (HI), conformity index (CI), and volume receiving 60 Co ViewRay treatments planned with its Monte Carlo treatment planning software were comparable with 6 MV plans computed with convolution superposition algorithm on Pinnacle treatment planning system. (author)

A dose homogeneity and conformity evaluation between ViewRay and pinnacle-based linear accelerator IMRT treatment plans.

Science.gov (United States)

Saenz, Daniel L; Paliwal, Bhudatt R; Bayouth, John E

2014-04-01

ViewRay, a novel technology providing soft-tissue imaging during radiotherapy is investigated for treatment planning capabilities assessing treatment plan dose homogeneity and conformity compared with linear accelerator plans. ViewRay offers both adaptive radiotherapy and image guidance. The combination of cobalt-60 (Co-60) with 0.35 Tesla magnetic resonance imaging (MRI) allows for magnetic resonance (MR)-guided intensity-modulated radiation therapy (IMRT) delivery with multiple beams. This study investigated head and neck, lung, and prostate treatment plans to understand what is possible on ViewRay to narrow focus toward sites with optimal dosimetry. The goal is not to provide a rigorous assessment of planning capabilities, but rather a first order demonstration of ViewRay planning abilities. Images, structure sets, points, and dose from treatment plans created in Pinnacle for patients in our clinic were imported into ViewRay. The same objectives were used to assess plan quality and all critical structures were treated as similarly as possible. Homogeneity index (HI), conformity index (CI), and volume receiving ViewRay treatments planned with its Monte Carlo treatment planning software were comparable with 6 MV plans computed with convolution superposition algorithm on Pinnacle treatment planning system.

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)

Assessing the quality of conformal treatment planning: a new tool for quantitative comparison

International Nuclear Information System (INIS)

Menhel, J; Levin, D; Alezra, D; Symon, Z; Pfeffer, R

2006-01-01

We develop a novel radiotherapy plan comparison index, critical organ scoring index (COSI), which is a measure of both target coverage and critical organ overdose. COSI is defined as COSI = 1 - (V(OAR) >tol /TC), where V(OAR) >tol is the fraction of volume of organ at risk receiving more than tolerance dose, and TC is the target coverage, V T,PI /V T , where V T,PI is the target volume receiving at a least prescription dose and V T is the total target volume. COSI approaches unity when the critical structure is completely spared and the target coverage is unity. We propose a two-dimensional, graphical representation of COSI versus conformity index (CI), where CI is a measure of a normal tissue overdose. We show that this 2D representation is a reliable, visual quantitative tool for evaluating competing plans. We generate COSI-CI plots for three sites: head and neck, cavernous sinus, and pancreas, and evaluate competing non-coplanar 3D and IMRT treatment plans. For all three sites this novel 2D representation assisted the physician in choosing the optimal plan, both in terms of target coverage and in terms of critical organ sparing. We verified each choice by analysing individual DVHs and isodose lines. Comparing our results to the widely used conformation number, we found that in all cases where there were discrepancies in the choice of the best treatment plan, the COSI-CI choice was considered the correct one, in several cases indicating that a non-coplanar 3D plan was superior to the IMRT plans. The choice of plan was quick, simple and accurate using the new graphical representation

Development of model plans in three dimensional conformal radiotherapy for brain tumors

International Nuclear Information System (INIS)

Pyo, Hongryull; Kim, Gwieon; Keum, Kichang; Chang, Sekyung; Suh, Changok; Lee, Sanghoon

2002-01-01

Three dimensional conformal radiotherapy planning is being used widely for the treatment of patients with brain tumor. However, it takes much time to develop an optimal treatment plan, therefore, it is difficult to apply this technique to all patients. To increase the efficiency of this technique, we need to develop standard radiotherapy plans for each site of the brain. Therefore we developed several 3 dimensional conformal radiotherapy plans (3D plans) for tumors at each site of brain, compared them with each other, and with 2 dimensional radiotherapy plans. Finally model plans for each site of the brain were decided. Imaginary tumors, with sizes commonly observed in the clinic, were designed for each site of the brain and drawn on CT images. The planning target volumes (PTVs) were as follows; temporal tumor-5.7 x 8.2 x 7.6 cm, suprasellar tumor-3 x 4 x 4.1 cm, thalamic tumor-3.1 x 5.9 x 3.7 cm, frontoparietal tumor-5.5 x 7 x 5.5 cm, and occipitoparietal tumor-5 x 5.5 x 5 cm. Plans using parallel opposed 2-portals and/or 3 portals including fronto-vertex and 2 lateral fields were developed manually as the conventional 2D plans, and 3D noncoplanar conformal plans were developed using beam's eye view and the automatic block drawing tool. Total tumor dose was 54 Gy for a suprasellar tumor, 59.4 Gy and 72 Gy for the other tumors. All dose plans (including 2D plans) were calculated using 3D plan software. Developed plans were compared with each other using dose-volume histograms (DVH), normal tissue complication probabilities (NTCP) and variable dose statistic values (minimum, maximum and mean dose, D5, V83, V85 and V95). Finally a best radiotherapy plan for each site of brain was selected. 1) Temporal tumor; NTCPs and DVHs of the normal tissue of all 3D plans were superior to 2D plans and this trend was more definite when total dose was escalated to 72 Gy (NTCPs of normal brain 2D plans: 27%, 8% → 3D plans: 1%, 1%). Various dose statistic values did not show any

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

Preliminary results of a new workflow for MRI/CT-based image-guided brachytherapy in cervical carcinoma.

Science.gov (United States)

Nemoto, Miho Watanabe; Iwai, Yuma; Togasaki, Gentaro; Kurokawa, Marie; Harada, Rintarou; Kobayashi, Hiroki; Uno, Takashi

2017-12-01

We propose a method of image-guided brachytherapy (IGBT) that combines MRI-based target volume delineation for the first fraction with CT datasets of subsequent fractions, using an automatic, applicator-based co-registration, and report our preliminary experience. The MRI of the first fraction was used for the first brachytherapy planning. For each subsequent brachytherapy fraction, after the same applicator insertion, a new CT scan with the applicator in place was obtained. The MR image set was registered to the subsequent brachytherapy treatment planning CT using the applicator for rigid body registration. To demonstrate the registration quality, we used here the Dice index as a measurement of tandem delineation overlap between CT and MRI. The median Dice index was 0.879 (range 0.610-0.932), which indicated that the contours on CT and MRI fitted well. With this combination method, the median D90 of HR CTV and the calculated D2 cm 3 of the bladder, rectum, and sigmoid in each fraction were 7.2 (4.0-10.4), 5.9 (2.3-7.7), 4.0 (1.9-6.7), and 3.8 (0.6-7.2) Gy, respectively. Our described method of MRI-guided IGBT offers a practical option for the benefits of target delineation.

Reduced dose to urethra and rectum with the use of variable needle spacing in prostate brachytherapy: a potential role for robotic technology

Science.gov (United States)

Vyas, Shilpa; Le, Yi; Zhang, Zhe; Armour, Woody

2015-01-01

Purpose Several robotic delivery systems for prostate brachytherapy are under development or in pre-clinical testing. One of the features of robotic brachytherapy is the ability to vary spacing of needles at non-fixed intervals. This feature may play an important role in prostate brachytherapy, which is traditionally template-based with fixed needle spacing of 0.5 cm. We sought to quantify potential reductions in the dose to urethra and rectum by utilizing variable needle spacing, as compared to fixed needle spacing. Material and methods Transrectal ultrasound images from 10 patients were used by 3 experienced planners to create 120 treatment plans. Each planner created 4 plan variations per patient with respect to needle positions: 125I fixed spacing, 125I variable spacing, 103Pd fixed spacing, and 103Pd variable spacing. The primary planning objective was to achieve a prostate V100 of 100% while minimizing dose to urethra and rectum. Results All plans met the objective of achieving prostate V100 of 100%. Combined results for all plans show statistically significant improvements in all assessed dosimetric variables for urethra (Umax, Umean, D30, D5) and rectum (Rmax, Rmean, RV100) when using variable spacing. The dose reductions for mean and maximum urethra dose using variable spacing had p values of 0.011 and 0.024 with 103Pd, and 0.007 and 0.029 with 125I plans. Similarly dose reductions for mean and maximum rectal dose using variable spacing had p values of 0.007 and 0.052 with 103Pd, and 0.012 and 0.037 with 125I plans. Conclusions The variable needle spacing achievable by the use of robotics in prostate brachytherapy allows for reductions in both urethral and rectal planned doses while maintaining prostate dose coverage. Such dosimetric advantages have the potential in translating to significant clinical benefits with the use of robotic brachytherapy. PMID:26622227

Conformity index: A review

International Nuclear Information System (INIS)

Feuvret, Loic; Noel, Georges; Mazeron, Jean-Jacques; Bey, Pierre

2006-01-01

We present a critical analysis of the conformity indices described in the literature and an evaluation of their field of application. Three-dimensional conformal radiotherapy, with or without intensity modulation, is based on medical imaging techniques, three-dimensional dosimetry software, compression accessories, and verification procedures. It consists of delineating target volumes and critical healthy tissues to select the best combination of beams. This approach allows better adaptation of the isodose to the tumor volume, while limiting irradiation of healthy tissues. Tools must be developed to evaluate the quality of proposed treatment plans. Dosimetry software provides the dose distribution in each CT section and dose-volume histograms without really indicating the degree of conformity. The conformity index is a complementary tool that attributes a score to a treatment plan or that can compare several treatment plans for the same patient. The future of conformal index in everyday practice therefore remains unclear

SU-G-201-09: Evaluation of a Novel Machine-Learning Algorithm for Permanent Prostate Brachytherapy Treatment Planning

International Nuclear Information System (INIS)

Nicolae, A; Lu, L; Morton, G; Chung, H; Helou, J; Al Hanaqta, M; Loblaw, A; Ravi, A; Heath, E

2016-01-01

Purpose: A novel, automated, algorithm for permanent prostate brachytherapy (PPB) treatment planning has been developed. The novel approach uses machine-learning (ML), a form of artificial intelligence, to substantially decrease planning time while simultaneously retaining the clinical intuition of plans created by radiation oncologists. This study seeks to compare the ML algorithm against expert-planned PPB plans to evaluate the equivalency of dosimetric and clinical plan quality. Methods: Plan features were computed from historical high-quality PPB treatments (N = 100) and stored in a relational database (RDB). The ML algorithm matched new PPB features to a highly similar case in the RDB; this initial plan configuration was then further optimized using a stochastic search algorithm. PPB pre-plans (N = 30) generated using the ML algorithm were compared to plan variants created by an expert dosimetrist (RT), and radiation oncologist (MD). Planning time and pre-plan dosimetry were evaluated using a one-way Student’s t-test and ANOVA, respectively (significance level = 0.05). Clinical implant quality was evaluated by expert PPB radiation oncologists as part of a qualitative study. Results: Average planning time was 0.44 ± 0.42 min compared to 17.88 ± 8.76 min for the ML algorithm and RT, respectively, a significant advantage [t(9), p = 0.01]. A post-hoc ANOVA [F(2,87) = 6.59, p = 0.002] using Tukey-Kramer criteria showed a significantly lower mean prostate V150% for the ML plans (52.9%) compared to the RT (57.3%), and MD (56.2%) plans. Preliminary qualitative study results indicate comparable clinical implant quality between RT and ML plans with a trend towards preference for ML plans. Conclusion: PPB pre-treatment plans highly comparable to those of an expert radiation oncologist can be created using a novel ML planning model. The use of an ML-based planning approach is expected to translate into improved PPB accessibility and plan uniformity.

SU-G-201-09: Evaluation of a Novel Machine-Learning Algorithm for Permanent Prostate Brachytherapy Treatment Planning

Energy Technology Data Exchange (ETDEWEB)

Nicolae, A [Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, ON (Canada); Department of Physics, Ryerson University, Toronto, ON (Canada); Lu, L; Morton, G; Chung, H; Helou, J; Al Hanaqta, M; Loblaw, A; Ravi, A [Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, ON (Canada); Heath, E [Carleton Laboratory for Radiotherapy Physics, Carleton University, Ottawa, ON, CA (Canada)

2016-06-15

Purpose: A novel, automated, algorithm for permanent prostate brachytherapy (PPB) treatment planning has been developed. The novel approach uses machine-learning (ML), a form of artificial intelligence, to substantially decrease planning time while simultaneously retaining the clinical intuition of plans created by radiation oncologists. This study seeks to compare the ML algorithm against expert-planned PPB plans to evaluate the equivalency of dosimetric and clinical plan quality. Methods: Plan features were computed from historical high-quality PPB treatments (N = 100) and stored in a relational database (RDB). The ML algorithm matched new PPB features to a highly similar case in the RDB; this initial plan configuration was then further optimized using a stochastic search algorithm. PPB pre-plans (N = 30) generated using the ML algorithm were compared to plan variants created by an expert dosimetrist (RT), and radiation oncologist (MD). Planning time and pre-plan dosimetry were evaluated using a one-way Student’s t-test and ANOVA, respectively (significance level = 0.05). Clinical implant quality was evaluated by expert PPB radiation oncologists as part of a qualitative study. Results: Average planning time was 0.44 ± 0.42 min compared to 17.88 ± 8.76 min for the ML algorithm and RT, respectively, a significant advantage [t(9), p = 0.01]. A post-hoc ANOVA [F(2,87) = 6.59, p = 0.002] using Tukey-Kramer criteria showed a significantly lower mean prostate V150% for the ML plans (52.9%) compared to the RT (57.3%), and MD (56.2%) plans. Preliminary qualitative study results indicate comparable clinical implant quality between RT and ML plans with a trend towards preference for ML plans. Conclusion: PPB pre-treatment plans highly comparable to those of an expert radiation oncologist can be created using a novel ML planning model. The use of an ML-based planning approach is expected to translate into improved PPB accessibility and plan uniformity.

Dosimetric Impact of Primary Planning Parameters in Dynamic Conformal Arc Technique for Lung SBRT

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Park, Ji Yeon; Suh, Tae Suk [Dept. of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of); Kim, Si Yong [Dept. of Radiation Oncology, Mayo Clinic, Jacksonvile (United States); Lee, Jeong Woo [Dept. of Radiation Oncology, Konkuk University Medical Center, Seoul (Korea, Republic of); Choi, Kyoung Sik [Dept. of Radiation Oncology, Anyang SAM Hospital, Anyang (Korea, Republic of)

2011-04-15

As one of the stereotactic body radiation therapy (SBRT) techniques, dynamic conformal arc therapy (DCAT) is commonly adopted to efficiently deliver conformal doses. However, as the DCAT uses numerous beams at individual control points, the dosimetric errors generated from each beam can be accumulated and manifested. In SBRT, therefore, due to the high fractional dose within a few fractions to moving target, the determination of the applied plan parameters can be critical and the evaluation of dosimetric impact of planning parameters would play an important role in DCAT planning process. In this study, we systematically evaluated the dosimetric influence caused by the variable grid size and the angular increment in DCAT for lung SBRT. Dose variations with different parameters were estimated for spherical and elongated tumors on an anthropomorphic phantom. The systematic analysis of the generated dose variation would guide to determine appropriate plan parameters and to estimate the dose errors in planning process in a clinical perspective of DCAT. It was found that two plan parameters, grid size and angular increment, in DCAT could cause non-negligible dose uncertainty. Coarse grid size led patients to get unnecessary overdose. Coarse angular increment could make significantly inaccurate prediction of OAR dose, resulting in either over- or under- estimation depending on the location of OAR relative to the isocenter.

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

The influence of the dwell time deviation constraint (DTDC) parameter on dosimetry with IPSA optimisation for HDR prostate brachytherapy

International Nuclear Information System (INIS)

Smith, Ryan L.; Millar, Jeremy L.; Panettieri, Vanessa; Mason, Natasha; Lancaster, Craig; Francih, Rick D.

2015-01-01

To investigate how the dwell time deviation constraint (DTDC) parameter, applied to inverse planning by simulated annealing (IPSA) optimisation limits large dwell times from occurring in each catheter and to characterise the effect on the resulting dosimetry for prostate high dose rate (HDR) brachytherapy treatment plans. An unconstrained IPSA optimised treatment plan, using the Oncentra Brachytherapy treatment planning system (version 4.3, Nucletron an Elekta company, Elekta AB, Stockholm, Sweden), was generated for 20 consecutive HDR prostate brachytherapy patients, with the DTDC set to zero. Successive constrained optimisation plans were also created for each patient by increasing the DTDC parameter by 0.2, up to a maximum value of 1.0. We defined a “plan modulation index”, to characterise the change of dwell time modulation as the DTDC parameter was increased. We calculated the dose volume histogram indices for the PTV (D90, V100, V150, V200%) and urethra (D10%) to characterise the effect on the resulting dosimetry. The average PTV D90% decreases as the DTDC is applied, on average by only 1.5 %, for a DTDC = 0.4. The measures of high dose regions in the PTV, V150 and V200%, increase on average by less than 5 and 2 % respectively. The net effect of DTDC on the modulation of dwell times has been characterised by the introduction of the plan modulation index. DTDC applied during IPSA optimisation of HDR prostate brachytherapy plans reduce the occurrence of large isolated dwell times within individual catheters. The mechanism by which DTDC works has been described and its effect on the modulation of dwell times has been characterised. The authors recommend using a DTDC parameter no greater than 0.4 to obtain a plan with dwell time modulation comparable to a geometric optimised plan. This yielded on average a 1.5 % decrease in PTV coverage and an acceptable increase in V150%, without compromising the urethral dose.

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)

Results of different modes conformal radiotherapy in treatment of cervical cancer

International Nuclear Information System (INIS)

Baranovs'ka, L.M.; Yivankova, V.S.; Khrulenko, T.V.; Skomorokhova, T.V.; Gorelyina, G.L.

2017-01-01

Development of techniques for cytotoxic treatment applying different modes of conformal radiotherapy, brachytherapy and high-energy (high dose rate - HDR) is one of the promising areas of optimization and efficiency of conservative treatment of patients with regional forms of cervical cancer. At Radiation Oncology Department, National Cancer Institute, 89 patients with stage 2b-3b cervical cancer, aged 29 to 70, underwent examination and combined radiotherapy course. The patients were divided into 2 main groups (56 patients) depending on the mode of developed conformal radiation therapy, and a control group made up by 33 patients (classic, default conformal radiotherapy). Results. Along with external beam radiotherapy, the patients of Group 2 were provided with conformal radiotherapy carried out by means of the linear accelerator of electrons in the mode of enhanced multi fractionation of irradiation dose applied to the small pelvis area (tumor and lymph efflux channels) with the single tumor dose 1.3 Gy twice per day once 4-6 hours up to the total radiation dose of 45 Gy applied to the small pelvis lymph nodes. The patients of Group 1 and the ones of the control group underwent conformal radiotherapy in the mode of standard fractionation applied to the small pelvis area with the single tumor dose of 1.8 Gy up to the total radiation dose of 45 Gy. Conformal radiotherapy was carried out for the patients of Group 1 associated with chemoradiomodifiers (tegafur, cisplatin). At the stage 2 of combined radiotherapy course, all patients underwent HDR brachytherapy via Co60 source in the mode of the single tumor dose of 5 Gy at point A up to the total radiation dose of 35-40 Gy. Therefore, employing accelerated mode of multifractiation in conformal radiotherapy of patients with regional cervical cancer makes it possible to enhance canrcinocidal irradiation doses applied to a tumor, and an interval between radiotherapy fractions provides conditions for initiation of

BrachyView: proof-of-principle of a novel in-body gamma camera for low dose-rate prostate brachytherapy.

Science.gov (United States)

Petasecca, M; Loo, K J; Safavi-Naeini, M; Han, Z; Metcalfe, P E; Meikle, S; Pospisil, S; Jakubek, J; Bucci, J A; Zaider, M; Lerch, M L F; Qi, Y; Rosenfeld, A B

2013-04-01

The conformity of the achieved dose distribution to the treatment plan strongly correlates with the accuracy of seed implantation in a prostate brachytherapy treatment procedure. Incorrect seed placement leads to both short and long term complications, including urethral and rectal toxicity. The authors present BrachyView, a novel concept of a fast intraoperative treatment planning system, to provide real-time seed placement information based on in-body gamma camera data. BrachyView combines the high spatial resolution of a pixellated silicon detector (Medipix2) with the volumetric information acquired by a transrectal ultrasound (TRUS). The two systems will be embedded in the same probe so as to provide anatomically correct seed positions for intraoperative planning and postimplant dosimetry. Dosimetric calculations are based on the TG-43 method using the real position of the seeds. The purpose of this paper is to demonstrate the feasibility of BrachyView using the Medipix2 pixel detector and a pinhole collimator to reconstruct the real-time 3D position of low dose-rate brachytherapy seeds in a phantom. BrachyView incorporates three Medipix2 detectors coupled to a multipinhole collimator. Three-dimensionally triangulated seed positions from multiple planar images are used to determine the seed placement in a PMMA prostate phantom in real time. MATLAB codes were used to test the reconstruction method and to optimize the device geometry. The results presented in this paper show a 3D position reconstruction accuracy of the seed in the range of 0.5-3 mm for a 10-60 mm seed-to-detector distance interval (Z direction), respectively. The BrachyView system also demonstrates a spatial resolution of 0.25 mm in the XY plane for sources at 10 mm distance from Medipix2 detector plane, comparable to the theoretical value calculated for an equivalent gamma camera arrangement. The authors successfully demonstrated the capability of BrachyView for real-time imaging (using a 3 s

BrachyView: Proof-of-principle of a novel in-body gamma camera for low dose-rate prostate brachytherapy

International Nuclear Information System (INIS)

Petasecca, M.; Loo, K. J.; Safavi-Naeini, M.; Han, Z.; Metcalfe, P. E.; Lerch, M. L. F.; Qi, Y.; Rosenfeld, A. B.; Meikle, S.; Pospisil, S.; Jakubek, J.; Bucci, J. A.; Zaider, M.

2013-01-01

Purpose: The conformity of the achieved dose distribution to the treatment plan strongly correlates with the accuracy of seed implantation in a prostate brachytherapy treatment procedure. Incorrect seed placement leads to both short and long term complications, including urethral and rectal toxicity. The authors present BrachyView, a novel concept of a fast intraoperative treatment planning system, to provide real-time seed placement information based on in-body gamma camera data. BrachyView combines the high spatial resolution of a pixellated silicon detector (Medipix2) with the volumetric information acquired by a transrectal ultrasound (TRUS). The two systems will be embedded in the same probe so as to provide anatomically correct seed positions for intraoperative planning and postimplant dosimetry. Dosimetric calculations are based on the TG-43 method using the real position of the seeds. The purpose of this paper is to demonstrate the feasibility of BrachyView using the Medipix2 pixel detector and a pinhole collimator to reconstruct the real-time 3D position of low dose-rate brachytherapy seeds in a phantom. Methods: BrachyView incorporates three Medipix2 detectors coupled to a multipinhole collimator. Three-dimensionally triangulated seed positions from multiple planar images are used to determine the seed placement in a PMMA prostate phantom in real time. MATLAB codes were used to test the reconstruction method and to optimize the device geometry. Results: The results presented in this paper show a 3D position reconstruction accuracy of the seed in the range of 0.5–3 mm for a 10–60 mm seed-to-detector distance interval (Z direction), respectively. The BrachyView system also demonstrates a spatial resolution of 0.25 mm in the XY plane for sources at 10 mm distance from Medipix2 detector plane, comparable to the theoretical value calculated for an equivalent gamma camera arrangement. The authors successfully demonstrated the capability of BrachyView for

In vivo dosimetry with semiconductors in medium dose rate (MDR) brachytherapy for cervical cancer.

Science.gov (United States)

Allahverdi, Mahmoud; Jaberi, Ramin; Aghili, Mehdi; Ghahremani, Fatemeh; Geraily, Ghazale

2013-03-01

This study was performed to evaluate the role of in vivo dosimetry with semiconductor detectors in gynaecological medium dose rate brachytherapy, and to compare the actual doses delivered to organs at risk (as measured using in vivo dosimetry) with those calculated during treatment planning. Doses to the rectum and bladder were measured in a group of patients with cervical carcinoma using semiconductor detectors and compared to the doses calculated using a treatment planning system. 36 applications of brachytherapy at dose rates of 1.8-2.3 Gy/h were performed in the patients. The mean differences between the measured and calculated doses were 3 % for the rectum and 11 % for the bladder. The main reason for the differences between the measured and calculated doses was patient movement. To reduce the risk of large errors in the dose delivered, in vivo dosimetry should be performed in addition to treatment planning system computations.

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

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

40 CFR 52.2133 - General conformity.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 4 2010-07-01 2010-07-01 false General conformity. 52.2133 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) South Carolina § 52.2133 General conformity. The General Conformity regulations adopted into the South Carolina State Implementation Plan which...

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.

Paddle-based rotating-shield brachytherapy

Energy Technology Data Exchange (ETDEWEB)

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

2015-10-15

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

40 CFR 51.854 - Conformity analysis.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Conformity analysis. 51.854 Section 51... FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Determining Conformity of General Federal Actions to State or Federal Implementation Plans § 51.854 Conformity analysis. Link to an...

Fully automated MRI-guided robotics for prostate brachytherapy

International Nuclear Information System (INIS)

Stoianovici, D.; Vigaru, B.; Petrisor, D.; Muntener, M.; Patriciu, A.; Song, D.

2008-01-01

The uncertainties encountered in the deployment of brachytherapy seeds are related to the commonly used ultrasound imager and the basic instrumentation used for the implant. An alternative solution is under development in which a fully automated robot is used to place the seeds according to the dosimetry plan under direct MRI-guidance. Incorporation of MRI-guidance creates potential for physiological and molecular image-guided therapies. Moreover, MRI-guided brachytherapy is also enabling for re-estimating dosimetry during the procedure, because with the MRI the seeds already implanted can be localised. An MRI compatible robot (MrBot) was developed. The robot is designed for transperineal percutaneous prostate interventions, and customised for fully automated MRI-guided brachytherapy. With different end-effectors, the robot applies to other image-guided interventions of the prostate. The robot is constructed of non-magnetic and dielectric materials and is electricity free using pneumatic actuation and optic sensing. A new motor (PneuStep) was purposely developed to set this robot in motion. The robot fits alongside the patient in closed-bore MRI scanners. It is able to stay fully operational during MR imaging without deteriorating the quality of the scan. In vitro, cadaver, and animal tests showed millimetre needle targeting accuracy, and very precise seed placement. The robot tested without any interference up to 7T. The robot is the first fully automated robot to function in MRI scanners. Its first application is MRI-guided seed brachytherapy. It is capable of automated, highly accurate needle placement. Extensive testing is in progress prior to clinical trials. Preliminary results show that the robot may become a useful image-guided intervention instrument. (author)

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)

Workflow efficiency for the treatment planning process in CT-guided high-dose-rate brachytherapy for cervical cancer.

Science.gov (United States)

Michaud, Anthony L; Benedict, Stanley; Montemayor, Eliseo; Hunt, Jon Paul; Wright, Cari; Mathai, Mathew; Mayadev, Jyoti S

2016-01-01

To investigate process efficiency, we present a prospective investigation of the treatment planning phase of image-guided brachytherapy (BT) for cervical cancer using a specific checklist. From October 2012 to January 2014, 76 BT procedures were consecutively performed. Prospective data on the CT-based treatment planning process was collected using a specific checklist which details the following steps: (1) dosimetry planning, (2) physician review start, (3) physician review time, (4) dosimetry processing, (5) physics review start, (6) physics review, and (7) procedural pause. Variables examined included the use of a pre-BT MRI, clinic duty conflicts, resident teaching, and the use of specific BT planners. Analysis was performed using descriptive statistics, t-test, and analysis of variance. Seventy-five prospectively gathered checklists comprised this analysis. The mean time for treatment planning was 95 minutes (med 94, std 18). The mean intervals in the above steps were (1) = 42, (2) = 5, (3) = 19, (4) = 10, (5) = 6, (6) = 13, and (7) = 26 minutes. There was no statistical difference in patients who had a pre-BT MRI. Resident teaching did not influence time, p = 0.17. Treatment planning time was decreased with a specific planner, p = 0.0015. A skillful team approach is required for treatment planning efficiency in image-guided BT. We have found that the specific BT planners can have a significant effect on the overall planning efficiency. We continue to examine clinical and workflow-related factors that will enhance our safety and workflow process with BT. Published by Elsevier Inc.

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...

TH-AB-BRA-04: Dosimetric Evaluation of MR-Guided HDR Brachytherapy Planning for Cervical Cancer

Energy Technology Data Exchange (ETDEWEB)

Kamio, Y; Barkati, M; Beliveau-Nadeau, D [CHUM Notre Dame Hospital, Montreal, QC, CA (Canada)

2016-06-15

Purpose: To perform a retrospective study on 16 patients that had both CT and T2-weighted MR scans done at first fraction using the Utrecht CT/MR applicator (Elekta Brachytherapy) in order to evaluate uncertainties associated with an MR-only planning workflow. Methods: MR-workflow uncertainties were classified in three categories: reconstruction, registration and contouring. A systematic comparison of the CT and MR contouring, manual reconstruction and optimization process was performed to evaluate the impact of these uncertainties on the recommended GEC ESTRO DVH parameters: D90% and V100% for HR-CTV as well as D2cc for bladder, rectum, sigmoid colon and small bowel. This comparison was done using the following four steps: 1. Catheter reconstruction done on MR images with original CT-plan contours and dwell times. 2. OAR contours adjusted on MR images with original CT-plan reconstruction and dwell times. 3. Both reconstruction and contours done on MR images with original CT-plan dwell times. 4. Entire MR-based workflow optimized dwell times reimported to the original CT-plan. Results: The MR-based reconstruction process showed average D2cc deviations of 4.5 ± 3.0%, 1.5 ± 2.0%, 2.5 ± 2.0% and 2.0 ± 1.0% for the bladder, rectum, sigmoid colon and small bowels respectively with a maximum of 10%, 6%, 6% and 4%. The HR-CTV’s D90% and V100% average deviations was found to be 4.0 ± 3.0%, and 2.0 ± 2.0% respectively with a maximum of 10% and 6%. Adjusting contours on MR-images was found to have a similar impact. Finally, the optimized MR-based workflow dwell times were found to still give acceptable plans when re-imported to the original CT-plan which validated the entire workflow. Conclusion: This work illustrates a systematic validation method for centers wanting to move towards an MR-only workflow. This work will be expanded to model based reconstruction, PD-weighted images and other types of applicators.

TH-AB-BRA-04: Dosimetric Evaluation of MR-Guided HDR Brachytherapy Planning for Cervical Cancer

International Nuclear Information System (INIS)

Kamio, Y; Barkati, M; Beliveau-Nadeau, D

2016-01-01

Purpose: To perform a retrospective study on 16 patients that had both CT and T2-weighted MR scans done at first fraction using the Utrecht CT/MR applicator (Elekta Brachytherapy) in order to evaluate uncertainties associated with an MR-only planning workflow. Methods: MR-workflow uncertainties were classified in three categories: reconstruction, registration and contouring. A systematic comparison of the CT and MR contouring, manual reconstruction and optimization process was performed to evaluate the impact of these uncertainties on the recommended GEC ESTRO DVH parameters: D90% and V100% for HR-CTV as well as D2cc for bladder, rectum, sigmoid colon and small bowel. This comparison was done using the following four steps: 1. Catheter reconstruction done on MR images with original CT-plan contours and dwell times. 2. OAR contours adjusted on MR images with original CT-plan reconstruction and dwell times. 3. Both reconstruction and contours done on MR images with original CT-plan dwell times. 4. Entire MR-based workflow optimized dwell times reimported to the original CT-plan. Results: The MR-based reconstruction process showed average D2cc deviations of 4.5 ± 3.0%, 1.5 ± 2.0%, 2.5 ± 2.0% and 2.0 ± 1.0% for the bladder, rectum, sigmoid colon and small bowels respectively with a maximum of 10%, 6%, 6% and 4%. The HR-CTV’s D90% and V100% average deviations was found to be 4.0 ± 3.0%, and 2.0 ± 2.0% respectively with a maximum of 10% and 6%. Adjusting contours on MR-images was found to have a similar impact. Finally, the optimized MR-based workflow dwell times were found to still give acceptable plans when re-imported to the original CT-plan which validated the entire workflow. Conclusion: This work illustrates a systematic validation method for centers wanting to move towards an MR-only workflow. This work will be expanded to model based reconstruction, PD-weighted images and other types of applicators.

Potential clinical efficacy of intensity-modulated conformal therapy

International Nuclear Information System (INIS)

Meeks, Sanford L.; Buatti, John M.; Bova, Francis J.; Friedman, William A.; Mendenhall, William M.; Zlotecki, Robert A.

1998-01-01

Purpose: The purpose of this study was to examine the potential benefit of using intensity-modulated conformal therapy for a variety of lesions currently treated with stereotactic radiosurgery or conventional radiotherapy. Methods and Materials: Intensity-modulated conformal treatment plans were generated for small intracranial lesions, as well as head and neck, lung, breast, and prostate cases, using the Peacock Plan[reg] treatment-planning system (Nomos Corporation). For small intracranial lesions, intensity-modulated conformal treatment plans were compared with stereotactic radiosurgery treatment plans generated for patient treatment at the University of Florida Shands Cancer Center. For other sites (head and neck, lung, breast, and prostate), plans generated using the Peacock Plan[reg] were compared with conventional treatment plans, as well as beam's-eye-view conformal treatment plans. Plan comparisons were accomplished through conventional qualitative review of two-dimensional (2D) dose distributions in conjunction with quantitative techniques, such as dose-volume histograms, dosimetric statistics, normal tissue complication probabilities, tumor control probabilities, and objective numerical scoring. Results: For small intracranial lesions, there is little difference between intensity-modulated conformal treatment planning and radiosurgery treatment planning in the conformation of high isodose lines with the target volume. However, stereotactic treatment planning provides a steeper dose gradient outside the target volume and, hence, a lower normal tissue toxicity index. For extracranial sites, objective numerical scores for beam's-eye-view and intensity-modulated conformal planning techniques are superior to scores for conventional treatment plans. The beam's-eye-view planning technique prevents geographic target misses and better excludes healthy tissues from the treatment portal. Compared with scores for the beam's-eye-view planning technique, scores for

Fricke gel-layer dosimetry in HDR brachytherapy

International Nuclear Information System (INIS)

Gambarini, G.; Negri, A.; Carrara, M.; Marchesini, R.

2008-01-01

Full text: In the last decade, technological improvements in radiotherapy have been significant and consequently the use and importance of radiotherapy in cancer treatment have increased greatly. In brachytherapy, new possibilities have been opened by the impressive progresses in 3D imaging, by the development of sophisticated techniques for modern afterloaders and by the constantly increasing speed and capacity of computers. However, these methodological improvements require corresponding improvements in the dosimetry methods, in order to ensure that the values calculated with computer treatment planning systems, adopted in the clinical praxis, agree with the delivered dose distributions. Fricke gel-layer dosimeters (FGLD) are under study by our group as a reliable alternative to films, semiconductors arrays or thermoluminescent dosimeters (TLDs). In the last years, we have significantly improved this technique by defining the FGLD best chemical composition, by optimizing the image acquisition assessment and by developing a dedicated software for image analysis. In this study, experimental measurements of planar dose distributions of a clinical 192 Ir source (Microselectron HDR, Nucletron) obtained by irradiating a series of piled-up FGL dosimeters in a tissue-equivalent phantom are presented. The obtained results were in accordance to TLD measurements and to treatment planning system (Plato, Nucletron) calculations. FGLD have proven to be a reliable tool to achieve HDR brachytherapy dose distribution measurements

Impact of catheter reconstruction error on dose distribution in high dose rate intracavitary brachytherapy and evaluation of OAR doses

International Nuclear Information System (INIS)

Thaper, Deepak; Shukla, Arvind; Rathore, Narendra; Oinam, Arun S.

2016-01-01

In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this study is to evaluate the impact of catheter reconstruction error on dose distribution in CT based intracavitary brachytherapy planning and evaluation of its effect on organ at risk (OAR) like bladder, rectum and sigmoid and target volume High risk clinical target volume (HR-CTV)

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.

Implementation of High-Dose-Rate Brachytherapy and Androgen Deprivation in Patients With Prostate Cancer

Energy Technology Data Exchange (ETDEWEB)

Lilleby, Wolfgang, E-mail: wolfgang.lilleby@ous-hf.no [Cancer Clinic, Oslo University Hospital, Norwegian Radiumhospital, Department of Radiotherapy and Oncology, Oslo (Norway); Tafjord, Gunnar; Raabe, Nils K. [Cancer Clinic, Oslo University Hospital, Norwegian Radiumhospital, Department of Radiotherapy and Oncology, Oslo (Norway)

2012-07-01

Purpose: To evaluate outcome (overall survival [OS], the actuarial 5-year cancer-specific survival [CSS], disease-free survival [DFS], biochemical failure-free survival [BFS]), complications and morbidity in patients treated with high-dose-rate brachytherapy (HDR-BT) boost and hormonal treatment with curative aims. Methods: Between 2004 and 2009, 275 prospectively followed pN0/N0M0 patients were included: 19 patients (7%) with T2, Gleason score 7 and prostate-specific antigen (PSA) <10 and 256 patients (93%) with T3 or Gleason score 8-10 or PSA >20 received multimodal treatment with conformal four-field radiotherapy (prostate/vesiculae 2 Gy Multiplication-Sign 25) combined with HDR-BT (iridium 192; prostate 10 Gy Multiplication-Sign 2) with long-term androgen deprivation therapy (ADT). Results: After a median observation time of 44.2 months (range, 10.4-90.5 months) 12 patients had relapsed clinically and/or biochemically and 10 patients were dead, of which 2 patients died from prostate cancer. Five-year estimates of BFS, CSS, DFS, and OS rates were 98.5%, 99.3%, 95.6%, and 96.3%, respectively. None of the patients with either Gleason score <8 or with intermediate risk profile had relapsed. The number of HDR-BT treatments was not related to outcome. Despite of age (median, 65.7 years; range, 45.7-77 years) and considerable pretreatment comorbidity in 39 of 275 patients, Genitourinary treatment-related morbidity was moderate with long-lasting Radiation Therapy Oncology Group Grade 2 voiding problems in 26 patients (9.5%) and occasionally mucous discharge in 20 patients (7%), none with Grade >2 for gastrointestinal at follow-up. Complications during implantations were related to pubic arch interference (4 patients) and lithotomy time, causing 2 patients to develop compartment syndrome. Conclusion: Despite still preliminary observations, our 5-year outcome estimates favor the implementation of high-dose-rate brachytherapy in high-risk patients combined with conformal

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)

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.

The brachytherapy with low dose-rate iridium for prostate cancer

International Nuclear Information System (INIS)

Momma, Tetsuo; Saito, Shiro; Ohki, Takahiro; Satoh, Hiroyuki; Toya, Kazuhito; Dokiya, Takushi; Murai, Masaru

2000-01-01

Brachytherapy as an option for the treatment of prostate cancer has been commonly performed in USA. As the permanent seeding of the radioactive materials is strictly restricted by the law in Japan, brachytherapy must be performed by the temporary implant. This treatment has been performed at a few facilities in Japan mostly using high dose-rate iridium. Only our facility has been using low dose-rate iridium (LDR-Ir) for prostate cancer. This study evaluates the clinical results of the treatment. Since December 1997 to December 1999, 26 patients with histologically diagnosed as prostate cancer (Stage B, 92%; Stage C, 8%) underwent brachytherapy. Twenty-two patients received brachytherapy alone, three were treated with a combination of brachytherapy and external beam radiotherapy (ERT) and one was treated with a combination of brachytherapy and neoadjuvant endocrine therapy. Patients ranged in age from 61 to 84 (median 76) years old. Treatment was initiated with perineal needle placement. From 10 to 14 needles were placed through the holes on the template which was fixed to the stabilizer of the transrectal ultrasound probe. After the needle placement, CT scan was performed to draw distribution curves for the treatment planning. LDR-Ir wires were introduced to the sheath and indwelled during the time calculated from dosimetry. Peripheral dose was 70 Gy for the monotherapy of brachytherapy. For the combination therapy, 40 Gy was given by brachytherapy and 36 Gy with ERT afterwards. LDR-Ir wires were removed after completion of the radiation and patients were followed with serum PSA level and annual biopsy. During 2 to 26 (median 12) months follow-up, 8 out of 9 patients with initial PSA level above 20 ng/ml showed PSA failure. All 13 patients with initial PSA level lower than 20 ng/ml were free from PSA failure. Eight out of 11 patients with Gleason's score 7 or higher showed PSA failure, and all 14 patients (including three patients with combined therapy) with

A brachytherapy photon radiation quality index Q(BT) for probe-type dosimetry.

Science.gov (United States)

Quast, Ulrich; Kaulich, Theodor W; Álvarez-Romero, José T; Carlsson Tedgren, Sa; Enger, Shirin A; Medich, David C; Mourtada, Firas; Perez-Calatayud, Jose; Rivard, Mark J; Zakaria, G Abu

2016-06-01

In photon brachytherapy (BT), experimental dosimetry is needed to verify treatment plans if planning algorithms neglect varying attenuation, absorption or scattering conditions. The detector's response is energy dependent, including the detector material to water dose ratio and the intrinsic mechanisms. The local mean photon energy E¯(r) must be known or another equivalent energy quality parameter used. We propose the brachytherapy photon radiation quality indexQ(BT)(E¯), to characterize the photon radiation quality in view of measurements of distributions of the absorbed dose to water, Dw, around BT sources. While the external photon beam radiotherapy (EBRT) radiation quality index Q(EBRT)(E¯)=TPR10(20)(E¯) is not applicable to BT, the authors have applied a novel energy dependent parameter, called brachytherapy photon radiation quality index, defined as Q(BT)(E¯)=Dprim(r=2cm,θ0=90°)/Dprim(r0=1cm,θ0=90°), utilizing precise primary absorbed dose data, Dprim, from source reference databases, without additional MC-calculations. For BT photon sources used clinically, Q(BT)(E¯) enables to determine the effective mean linear attenuation coefficient μ¯(E) and thus the effective energy of the primary photons Eprim(eff)(r0,θ0) at the TG-43 reference position Pref(r0=1cm,θ0=90°), being close to the mean total photon energy E¯tot(r0,θ0). If one has calibrated detectors, published E¯tot(r) and the BT radiation quality correction factor [Formula: see text] for different BT radiation qualities Q and Q0, the detector's response can be determined and Dw(r,θ) measured in the vicinity of BT photon sources. This novel brachytherapy photon radiation quality indexQ(BT) characterizes sufficiently accurate and precise the primary photon's penetration probability and scattering potential. Copyright © 2016. Published by Elsevier Ltd.

SU-F-T-08: Brachytherapy Film Dosimetry in a Water Phantom for a Ring and Tandem HDR Applicator

International Nuclear Information System (INIS)

Lee, B; Grelewicz, Z; Kang, Z; Cutright, D; Gopalakrishnan, M; Sathiaseelan, V; Zhang, H

2016-01-01

Purpose: The feasibility of dose measurement using new generation EBT3 film was explored in a water phantom for a ring and tandem HDR applicator for measurements tracking mucosal dose during cervical brachytherapy. Methods: An experimental fixture was assembled to position the applicator in a water phantom. Prior to measurement, calibration curves for EBT3 film in water and in solidwater were verified. EBT3 film was placed at different known locations around the applicator in the water tank. A CT scan of the phantom with applicator was performed using clinical protocol. A typical cervical cancer treatment plan was then generated by Oncentra brachytherapy planning system. A dose of 500 cGy was prescribed to point A (2 cm, 2 cm). Locations measured by film included the outer surface of the ring, measurement point A-m (2.2 cm, 2.2 cm), and profiles extending from point A-m parallel to the tandem. Three independent measurements were conducted. The doses recorded by film were carefully analyzed and compared with values calculated by the treatment planning system. Results: Assessment of the EBT3 films indicate that the dose at point A matches the values predicted by the planning system. Dose to the point A-m was 411.5 cGy, and the outer circumferential surface dose of the ring was between 500 and 1150 cGy. It was found that from the point A-m, the dose drops 60% within 4.5 cm on the line parallel to the tandem. The measurement doses agree with the treatment planning system. Conclusion: Use of EBT3 film is feasible for in-water measurements for brachytherapy. A carefully machined apparatus will likely improve measurement accuracy. In a typical plan, our study found that the ring surface dose can be 2.5 times larger than the point A prescription dose. EBT3 film can be used to monitor mucosal dose in brachytherapy treatments.

SU-F-T-08: Brachytherapy Film Dosimetry in a Water Phantom for a Ring and Tandem HDR Applicator

Energy Technology Data Exchange (ETDEWEB)

Lee, B; Grelewicz, Z; Kang, Z; Cutright, D; Gopalakrishnan, M; Sathiaseelan, V; Zhang, H [Northwestern Memorial Hospital, Chicago, IL (United States)

2016-06-15

Purpose: The feasibility of dose measurement using new generation EBT3 film was explored in a water phantom for a ring and tandem HDR applicator for measurements tracking mucosal dose during cervical brachytherapy. Methods: An experimental fixture was assembled to position the applicator in a water phantom. Prior to measurement, calibration curves for EBT3 film in water and in solidwater were verified. EBT3 film was placed at different known locations around the applicator in the water tank. A CT scan of the phantom with applicator was performed using clinical protocol. A typical cervical cancer treatment plan was then generated by Oncentra brachytherapy planning system. A dose of 500 cGy was prescribed to point A (2 cm, 2 cm). Locations measured by film included the outer surface of the ring, measurement point A-m (2.2 cm, 2.2 cm), and profiles extending from point A-m parallel to the tandem. Three independent measurements were conducted. The doses recorded by film were carefully analyzed and compared with values calculated by the treatment planning system. Results: Assessment of the EBT3 films indicate that the dose at point A matches the values predicted by the planning system. Dose to the point A-m was 411.5 cGy, and the outer circumferential surface dose of the ring was between 500 and 1150 cGy. It was found that from the point A-m, the dose drops 60% within 4.5 cm on the line parallel to the tandem. The measurement doses agree with the treatment planning system. Conclusion: Use of EBT3 film is feasible for in-water measurements for brachytherapy. A carefully machined apparatus will likely improve measurement accuracy. In a typical plan, our study found that the ring surface dose can be 2.5 times larger than the point A prescription dose. EBT3 film can be used to monitor mucosal dose in brachytherapy treatments.

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

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 ...

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

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.

Individualized margins in 3D conformal radiotherapy planning for lung cancer: analysis of physiological movements and their dosimetric impacts.

Science.gov (United States)

Germain, François; Beaulieu, Luc; Fortin, André

2008-01-01

In conformal radiotherapy planning for lung cancer, respiratory movements are not taken into account when a single computed tomography (CT) scan is performed. This study examines tumor movements to design individualized margins to account for these movements and evaluates their dosimetric impacts on planning volume. Fifteen patients undergoing CT-based planning for radical radiotherapy for localized lung cancer formed the study cohort. A reference plan was constructed based on reference gross, clinical, and planning target volumes (rGTV, rCTV, and rPTV, respectively). The reference plans were compared with individualized plans using individualized margins obtained by using 5 serial CT scans to generate individualized target volumes (iGTV, iCTV, and iPTV). Three-dimensional conformal radiation therapy was used for plan generation using 6- and 23-MV photon beams. Ten plans for each patient were generated and dose-volume histograms (DVHs) were calculated. Comparisons of volumetric and dosimetric parameters were performed using paired Student t-tests. Relative to the rGTV, the total volume occupied by the superimposed GTVs increased progressively with each additional CT scans. With the use of all 5 scans, the average increase in GTV was 52.1%. For the plans with closest dosimetric coverage, target volume was smaller (iPTV/rPTV ratio 0.808) but lung irradiation was only slightly decreased. Reduction in the proportion of lung tissue that received 20 Gy or more outside the PTV (V20) was observed both for 6-MV plans (-0.73%) and 23-MV plans (-0.65%), with p = 0.02 and p = 0.04, respectively. In conformal RT planning for the treatment of lung cancer, the use of serial CT scans to evaluate respiratory motion and to generate individualized margins to account for these motions produced only a limited lung sparing advantage.

Individualized Margins in 3D Conformal Radiotherapy Planning for Lung Cancer: Analysis of Physiological Movements and Their Dosimetric Impacts

International Nuclear Information System (INIS)

Germain, Francois; Beaulieu, Luc; Fortin, Andre

2008-01-01

In conformal radiotherapy planning for lung cancer, respiratory movements are not taken into account when a single computed tomography (CT) scan is performed. This study examines tumor movements to design individualized margins to account for these movements and evaluates their dosimetric impacts on planning volume. Fifteen patients undergoing CT-based planning for radical radiotherapy for localized lung cancer formed the study cohort. A reference plan was constructed based on reference gross, clinical, and planning target volumes (rGTV, rCTV, and rPTV, respectively). The reference plans were compared with individualized plans using individualized margins obtained by using 5 serial CT scans to generate individualized target volumes (iGTV, iCTV, and iPTV). Three-dimensional conformal radiation therapy was used for plan generation using 6- and 23-MV photon beams. Ten plans for each patient were generated and dose-volume histograms (DVHs) were calculated. Comparisons of volumetric and dosimetric parameters were performed using paired Student t-tests. Relative to the rGTV, the total volume occupied by the superimposed GTVs increased progressively with each additional CT scans. With the use of all 5 scans, the average increase in GTV was 52.1%. For the plans with closest dosimetric coverage, target volume was smaller (iPTV/rPTV ratio 0.808) but lung irradiation was only slightly decreased. Reduction in the proportion of lung tissue that received 20 Gy or more outside the PTV (V20) was observed both for 6-MV plans (-0.73%) and 23-MV plans (-0.65%), with p = 0.02 and p = 0.04, respectively. In conformal RT planning for the treatment of lung cancer, the use of serial CT scans to evaluate respiratory motion and to generate individualized margins to account for these motions produced only a limited lung sparing advantage

SU-E-J-222: Evaluation of Deformable Registration of PET/CT Images for Cervical Cancer Brachytherapy

International Nuclear Information System (INIS)

Liao, Y; Turian, J; Templeton, A; Kiel, K; Chu, J; Kadir, T

2014-01-01

Purpose: PET/CT provides important functional information for radiotherapy targeting of cervical cancer. However, repeated PET/CT procedures for external beam and subsequent brachytherapy expose patients to additional radiation and are not cost effective. Our goal is to investigate the possibility of propagating PET-active volumes for brachytherapy procedures through deformable image registration (DIR) of earlier PET/CT and ultimately to minimize the number of PET/CT image sessions required. Methods: Nine cervical cancer patients each received their brachytherapy preplanning PET/CT at the end of EBRT with a Syed template in place. The planning PET/CT was acquired on the day of brachytherapy treatment with the actual applicator (Syed or Tandem and Ring) and rigidly registered. The PET/CT images were then deformably registered creating a third (deformed) image set for target prediction. Regions of interest with standardized uptake values (SUV) greater than 65% of maximum SUV were contoured as target volumes in all three sets of PET images. The predictive value of the registered images was evaluated by comparing the preplanning and deformed PET volumes with the planning PET volume using Dice's coefficient (DC) and center-of-mass (COM) displacement. Results: The average DCs were 0.12±0.14 and 0.19±0.16 for rigid and deformable predicted target volumes, respectively. The average COM displacements were 1.9±0.9 cm and 1.7±0.7 cm for rigid and deformable registration, respectively. The DCs were improved by deformable registration, however, both were lower than published data for DIR in other modalities and clinical sites. Anatomical changes caused by different brachytherapy applicators could have posed a challenge to the DIR algorithm. The physiological change from interstitial needle placement may also contribute to lower DC. Conclusion: The clinical use of DIR in PET/CT for cervical cancer brachytherapy appears to be limited by applicator choice and requires further

Verification of dosimetry planning in brachytherapy in format Dicom and EUD calculation of Risk in bodies; Verificacion de la planificacion dosimetria en braquiterapia en formato Dicom y calculo del EUD en organos de riesgo

Energy Technology Data Exchange (ETDEWEB)

Garcia Hernandez, M. J.; Sendon del Rio, J. R.; Ayala Lazaro, R.; Jimenez Rojas, M. R.; Gomez Cores, S.; Polo Cezon, R.; Lopez Bote, M. A.

2013-07-01

This work Describes a program that automates the verification of the schedules in brachytherapy (configuration and dosimetric treatment parameters) for sources of Ir-192 (mHDR v2) and Co-60 (Co0.A86) from the plan exported in DICOM format data. (Author)

Feasibility of four-dimensional conformal planning for robotic radiosurgery

International Nuclear Information System (INIS)

Schlaefer, A.; Fisseler, J.; Dieterich, S.; Shiomi, H.; Cleary, K.; Schweikard, A.

2005-01-01

Organ motion can have a severe impact on the dose delivered by radiation therapy, and different procedures have been developed to address its effects. Conventional techniques include breath hold methods and gating. A different approach is the compensation for target motion by moving the treatment beams synchronously. Practical results have been reported for robot based radiosurgery, where a linear accelerator mounted on a robotic arm delivers the dose. However, not all organs move in the same way, which results in a relative motion of the beams with respect to the body and the tissues in the proximity of the tumor. This relative motion can severely effect the dose delivered to critical structures. We propose a method to incorporate motion in the treatment planning for robotic radiosurgery to avoid potential overdosing of organs surrounding the target. The method takes into account the motion of all considered volumes, which is discretized for dose calculations. Similarly, the beam motion is taken into account and the aggregated dose coefficient over all discrete steps is used for planning. We simulated the treatment of a moving target with three different planning methods. First, we computed beam weights based on a 3D planning situation and simulated treatment with organ motion and the beams moving synchronously to the target. Second, beam weights were computed by the 4D planning method incorporating the organ and beam motion and treatment was simulated for beams moving synchronously to the target. Third, the beam weights were determined by the 4D planning method with the beams fixed during planning and simulation. For comparison we also give results for the 3D treatment plan if there was no organ motion and when the plan is delivered by fixed beams in the presence of organ motion. The results indicate that the new 4D method is preferable and can further improve the overall conformality of motion compensated robotic radiosurgery

Development of novel conformity indices for quantitative comparison of radiation treatment plans

Energy Technology Data Exchange (ETDEWEB)

Park, Jong Min; Park, So Yeon; Wu, Hong Gyun; Ye, Sung Joon; Kim, Jin Ho; Kim, Jung In [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

2013-11-15

The conformity index (CI) is an indicator to assess the degree of congruence between a shape of reference isodose volume (VRI) and a shape of the target volume (TV). Two concepts are included in the CI, which are the target coverage and the degree of normal tissue sparing in the proximity of the target. Even though this could be verified by a manual review of dose distributions calculated on patient CT images slice by slice, detailed comparisons among several treatment plans would be inconvenient. The conformity could be also verified by reviewing dose-volume histograms (DVHs) of each structure calculated by treatment planning system (TPS). The prerequisite for this is the contouring of not only organs at risk (OARs) but also every structure in a patient body, which is not practical in the clinic. Therefore, a value possible to quantify the conformity was needed, and various studies on CI have been performed. Various CIs have been developed since 1993. Most of them are based on the calculation of the volumes except for the CI suggested by Wu et al. and Cheung et al. which were based on the distance. The aim of this study was to develop new CIs based on the calculations of angles and distances. The CI angle based on the analysis of the angle differences as well as the CIabs{sub d}istance and the CIdistance based on the analysis of the distances between the TV and the VRI were developed and evaluated in this study. The CI distance with Sornatomedins better performances than the CIangle and the CIabs{sub d}istance as well as the conventional CIs in various situations.

Online in vivo dosimetry in conformal radio therapies with MOSkin detectors

International Nuclear Information System (INIS)

Gambarini, G.; Tenconi, C.; Mantaut, N.; Carrara, M.; Borroni, M.; Pignoli, E.; Cutajar, D.; Petasecca, M.; Fuduli, I.; Lerch, M.; Rosenfeld, A.

2012-10-01

A novel MOSFET based dosimeter, the MOSkin, has been developed at the Centre for Medical Radiation Physics, University of Wollongong (Australia). This dosimeter is designed with suitable packaging that allows skin dose measurements at depths of 0.07 mm, as recommended by the ICRP. Initially proposed for real-time skin dose measurement, it is now studied for real-time in vivo dosimetry during high dose rate (Hdr) brachytherapy and intensity modulated radiotherapy. MOSkin detectors have shown good characteristics of reproducibility and linearity. Experiments performed with the 192 Ir source of a Hdr brachytherapy facility have shown negligible energy response for photons from the Ir-192 source. The angular response is within the experimental error when used in a dual-MOSkin configuration. In this work, urethral dose measurements were performed in a tissue-equivalent phantom reproducing prostate brachytherapy treatments. The obtained urethral doses were compared to the dose values calculated by the treatment planning system and the discrepancy was found to be within 4%, showing that dual-MOSkin detectors can be profitably utilized for real-time in vivo dosimetry during a brachytherapy treatment. (Author)

SU-F-BRA-05: Utility of the Combined Use of Two Types of HDR Sources with the Direction Modulation 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, Nevada (United States); Scanderbeg, D [UCSD Medical Center, La Jolla, CA (United States)

2015-06-15

Purpose: To maximize the dose to HRCTV while minimizing dose to the OARs, the combination of two HDR brachytherapy sources, 192-Ir and 169-Yb, used in combination with the recently-proposed novel direction modulated brachytherapy (DMBT) tandem applicator were examined. Methods: The DMBT tandem, made from nonmagnetic tungsten-alloy rod, with diameter of 5.4mm, has 6 symmetric peripheral holes of 1.3mm diameter. The 0.3mm thick bio-compatible plastic tubing wraps the tandem. MCNPX v.2.6 was used to simulate the mHDR 192-Ir V2 and 4140 HDR 169-Yb sources inside the DMBT applicator. Thought was by combining the higher energy 192-Ir (380keV) and lower energy 169-Yb (92.7keV) sources could create unprecedented level of dose conformality when combined with the high-degree intensity modulation capable DMBT tandem applicator. 3D dose matrices, with 1 mm3 resolution, were imported into an in-house-coded inverse optimization planning system to evaluate plan quality of 19 clinical patient cases. Prescription dose was 15Gy. All plans were normalized to receive the same HRCTV D90. Results: Generally, the use of dual sources produced better plans than using either of the sources alone, with significantly better performance in some patients. The mean D2cc for bladder, rectum, and sigmoid were 11.65±2.30Gy, 7.47±3.05Gy, and 9.84±2.48Gy for 192-Ir-only, respectively. For 169 -Yb-only, they were 11.67±2.26Gy, 7.44±3.02Gy, and 9.83±2.38Gy, respectively. The corresponding data for the dual sources were 11.51±2.24Gy, 7.30±3.00Gy, and 9.68 ±2.39Gy, respectively. The HRCTV D98 and V100 were 16.37±1.86Gy and 97.37±1.92Gy for Ir-192-only, respectively. For 169-Yb-only, they were 16.43±1.86Gy, and 97.51±1.91Gy, respectively. For the dual source, they were 16.42±1.87Gy and 97.47±1.93Gy, respectively. Conclusion: The plan quality improves, in some cases quite significantly, for when dual 192-Ir and 169-Yb sources are used in combination with highly intensity modulation capable

Brachytherapy dose-volume histogram computations using optimized stratified sampling methods

International Nuclear Information System (INIS)

Karouzakis, K.; Lahanas, M.; Milickovic, N.; Giannouli, S.; Baltas, D.; Zamboglou, N.

2002-01-01

A stratified sampling method for the efficient repeated computation of dose-volume histograms (DVHs) in brachytherapy is presented as used for anatomy based brachytherapy optimization methods. The aim of the method is to reduce the number of sampling points required for the calculation of DVHs for the body and the PTV. From the DVHs are derived the quantities such as Conformity Index COIN and COIN integrals. This is achieved by using partial uniform distributed sampling points with a density in each region obtained from a survey of the gradients or the variance of the dose distribution in these regions. The shape of the sampling regions is adapted to the patient anatomy and the shape and size of the implant. For the application of this method a single preprocessing step is necessary which requires only a few seconds. Ten clinical implants were used to study the appropriate number of sampling points, given a required accuracy for quantities such as cumulative DVHs, COIN indices and COIN integrals. We found that DVHs of very large tissue volumes surrounding the PTV, and also COIN distributions, can be obtained using a factor of 5-10 times smaller the number of sampling points in comparison with uniform distributed points

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

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, ...

Matlab Tools: An Alternative to Planning Systems in Brachytherapy Treatments

International Nuclear Information System (INIS)

Herrera, Higmar; Rodriguez, Mercedes; Rodriguez, Miguel

2006-01-01

This work proposes the use of the Matlab environment to obtain the treatment dose based on the reported data by Krishnaswamy and Liu et al. The comparison with reported measurements is showed for the Amersham source model. For the 3M source model, measurements with TLDs and a Monte Carlo simulation are compared to the data obtained by Matlab. The difference for the Amersham model is well under the 15% recommended by the IAEA and for the 3M model, although the difference is greater, the results are consistent. The good agreement to the reported data allows the Matlab calculations to be used in daily brachytherapy treatments

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

Dose-volume analysis for quality assurance of interstitial brachytherapy for breast cancer

International Nuclear Information System (INIS)

Vicini, Frank A.; Kestin, Larry L.; Edmundson, Gregory K.; Jaffray, David A.; Wong, John W.; Kini, Vijay R.; Chen, Peter Y.; Martinez, Alvaro A.

1999-01-01

Purpose/Objective: The use of brachytherapy in the management of breast cancer has increased significantly over the past several years. Unfortunately, few techniques have been developed to compare dosimetric quality and target volume coverage concurrently. We present a new method of implant evaluation that incorporates computed tomography-based three-dimensional (3D) dose-volume analysis with traditional measures of brachytherapy quality. Analyses performed in this fashion will be needed to ultimately assist in determining the efficacy of breast implants. Methods and Materials: Since March of 1993, brachytherapy has been used as the sole radiation modality after lumpectomy in selected protocol patients with early-stage breast cancer treated with breast-conserving therapy. Eight patients treated with high-dose-rate (HDR) brachytherapy who had surgical clips outlining the lumpectomy cavity and underwent computed tomography (CT) scanning after implant placement were selected for this study. For each patient, the postimplant CT dataset was transferred to a 3D treatment planning system. The lumpectomy cavity, target volume (lumpectomy cavity plus a 1-cm margin), and entire breast were outlined on each axial slice. Once all volumes were entered, the programmed HDR brachytherapy source positions and dwell times were imported into the 3D planning system. Using the tools provided by the 3D planning system, the implant dataset was then registered to the visible implant template in the CT dataset. The distribution of the implant dose was analyzed with respect to defined volumes via dose-volume histograms (DVH). Isodose surfaces, the dose homogeneity index, and dosimetric coverage of the defined volumes were calculated and contrasted. All patients received 32 Gy to the entire implanted volume in 8 fractions of 4 Gy over 4 days. Results: Three-plane implants were used for 7 patients and a two-plane implant for 1 patient. The median number of needles per implant was 16.5 (range

A dose homogeneity and conformity evaluation between ViewRay and pinnacle-based linear accelerator IMRT treatment plans

OpenAIRE

Daniel L Saenz; Bhudatt R Paliwal; John E Bayouth

2014-01-01

ViewRay, a novel technology providing soft-tissue imaging during radiotherapy is investigated for treatment planning capabilities assessing treatment plan dose homogeneity and conformity compared with linear accelerator plans. ViewRay offers both adaptive radiotherapy and image guidance. The combination of cobalt-60 (Co-60) with 0.35 Tesla magnetic resonance imaging (MRI) allows for magnetic resonance (MR)-guided intensity-modulated radiation therapy (IMRT) delivery with multiple beams. This ...

SU-E-T-263: Point Dose Variation Using a Single Ir-192 HDR Brachytherapy Plan for Two Treatments with a Single Tandem-Ovoid Insertion for Cervical Cancer

Energy Technology Data Exchange (ETDEWEB)

Liang, X; Morrill, S; Hardee, M; Han, E; Penagaricano, J; Zhang, X; Vaneerat, R [University of Arkansas Medical Science, Little Rock, AR (United States)

2014-06-01

Purpose: To evaluate the point dose variations between Ir-192 HDR treatments on two consecutive days using a single tandem-ovoid insertion without replanning in cervical cancer patients. Methods: This study includes eleven cervical cancer patients undergoing HDR brachytherapy with a prescribed dose of 28 Gy in 4 fractions. Each patient had two tandemovoid insertions one week apart. Each insertion was treated on consecutive days with rescanning and replanning prior to each treatment. To study the effect of no replanning for day 2 treatments, the day 1 plan dwell position and dwell time with decay were applied to the day 2 CT dataset. The point dose variations on the prescription point H (defined according to American Brachytherapy Society), and normal tissue doses at point B, bladder, rectum and vaginal mucosa (based on ICRU Report 38) were obtained. Results: Without replanning, the mean point H dose variation was 4.6 ± 10.7% on the left; 2.3 ± 2.9% on the right. The mean B point variation was 3.8 ± 4.9% on the left; 3.6 ± 4.7% on the right. The variation in the left vaginal mucosal point was 12.2 ± 10.7%; 9.5 ± 12.5% on the right; the bladder point 5.5 ± 7.4%; and the rectal point 7.9 ± 9.1%. Conclusion: Without replanning, there are variations both in the prescription point and the normal tissue point doses. The latter can vary as much as 10% or more. This is likely due to the steep dose gradient from brachytherapy compounded by shifts in the positions of the applicator in relationship to the patients anatomy. Imaging prior to each treatment and replanning ensure effective and safe brachytherapy are recommended.

Conformity index for brain cancer patients

International Nuclear Information System (INIS)

Petkovska, Sonja; Tolevska, Cveta; Kraleva, Slavica; Petreska, Elena

2010-01-01

The purpose of this study is to present the level of conformity achieved by using 3D conformal radiotherapy for brain cancer patients. Conformity index is a helpful quantitative tool for assessing (evaluating) the quality of a treatment plan. Treatment plans made for ninety patients with brain tumor are worked on this paper. The patients are in supine position and immobilized with thermoplastic masks for the head. Computed tomography data sets with 5 mm scan thickness are used to create a 3D image. All structures of interest are contoured. In order to obtain an optimal dose distribution, treatment fields are fit around target volume with set-up margins of 7mm in each direction. The conformity index values are between 1.21 and 2.04. Value of 1.8 is exceeded in eighteen cases; nine of them are bigger than 1.9 and only three of them are above 2. The target volume for each of these extreme CI values is ideal covered (between 95% and 105% of the prescribed dose). The most acceptable conformity index value in this paper belongs to the plan with the lowest minimal dose (84.7%). It can be concluded that conformity index is necessary but not sufficient factor for assessing radiation treatment plan conformity. To be able to estimate the acceptability of some treatment plan in daily practice, additional information as minimal, maximal and mean dose into target volume, as well as health tissues coverage must be taken into account.(Author)

Evaluation of radiation doses on critical organs in the treatment of cancer of the cervix using HDR-brachytherapy

International Nuclear Information System (INIS)

Soares, Taciana; Jansem, Teresa

2000-01-01

High dose-rate (HDR) brachytherapy is one type of treatment of the cervix carcinoma. During the planning for this therapy, especial attention is given to proximal normal organs such as bladder and rectum. In fact, due to their radiosensibility and localization, bladder and rectum are considered as critical organs. In this work we have studied the influence of the positioning of patient legs in the dose delivered to these critical organs in the treatment of cancer of the cervix using HDR-brachytherapy. (author)

Assessment of I-125 seed implant accuracy when using the live-planning technique for low dose rate prostate brachytherapy

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Moorrees Joshua

2012-11-01

Full Text Available Abstract Background Low risk prostate cancers are commonly treated with low dose rate (LDR brachytherapy involving I-125 seeds. The implementation of a ‘live-planning’ technique at the Royal Adelaide Hospital (RAH in 2007 enabled the completion of the whole procedure (i.e. scanning, planning and implant in one sitting. ‘Live-planning’ has the advantage of a more reliable delivery of the planned treatment compared to the ‘traditional pre-plan’ technique (where patient is scanned and planned in the weeks prior to implant. During live planning, the actual implanted needle positions are updated real-time on the treatment planning system and the dosimetry is automatically recalculated. The aim of this investigation was to assess the differences and clinical relevance between the planned dosimetry and the updated real-time implant dosimetry. Methods A number of 162 patients were included in this dosimetric study. A paired t-test was performed on the D90, V100, V150 and V200 target parameters and the differences between the planned and implanted dose distributions were analysed. Similarly, dosimetric differences for the organs at risk (OAR were also evaluated. Results Small differences between the primary dosimetric parameters for the target were found. Still, the incidence of hotspots was increased with approximately 20% for V200. Statistically significant increases were observed in the doses delivered to the OAR between the planned and implanted data; however, these increases were consistently below 3% thus probably without clinical consequences. Conclusions The current study assessed the accuracy of prostate implants with I-125 seeds when compared to initial plans. The results confirmed the precision of the implant technique which RAH has in place. Nevertheless, geographical misses, anatomical restrictions and needle displacements during implant can have repercussions for centres without live-planning option if dosimetric changes are not

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

Health-Related Quality of Life 2 Years After Treatment With Radical Prostatectomy, Prostate Brachytherapy, or External Beam Radiotherapy in Patients With Clinically Localized Prostate Cancer

International Nuclear Information System (INIS)

Ferrer, Montserrat; Suarez, Jose Francisco; Guedea, Ferran; Fernandez, Pablo; Macias, Victor; Marino, Alfonso; Hervas, Asuncion; Herruzo, Ismael; Ortiz, Maria Jose; Villavicencio, Humberto; Craven-Bratle, Jordi; Garin, Olatz; Aguilo, Ferran

2008-01-01

Purpose: To compare treatment impact on health-related quality of life (HRQL) in patients with localized prostate cancer, from before treatment to 2 years after the intervention. Methods and Materials: This was a longitudinal, prospective study of 614 patients with localized prostate cancer treated with radical prostatectomy (134), three-dimensional external conformal radiotherapy (205), and brachytherapy (275). The HRQL questionnaires administered before and after treatment (months 1, 3, 6, 12, and 24) were the Medical Outcomes Study 36-Item Short Form, the Functional Assessment of Cancer Therapy (General and Prostate Specific), the Expanded Prostate Cancer Index Composite (EPIC), and the American Urological Association Symptom Index. Differences between groups were tested by analysis of variance and within-group changes by univariate repeated-measures analysis of variance. Generalized estimating equations (GEE) models were constructed to assess between-group differences in HRQL at 2 years of follow-up after adjusting for clinical variables. Results: In each treatment group, HRQL initially deteriorated after treatment with subsequent partial recovery. However, some dimension scores were still significantly lower after 2 years of treatment. The GEE models showed that, compared with the brachytherapy group, radical prostatectomy patients had worse EPIC sexual summary and urinary incontinence scores (-20.4 and -14.1; p < 0.001), and external radiotherapy patients had worse EPIC bowel, sexual, and hormonal summary scores (-3.55, -5.24, and -1.94; p < 0.05). Prostatectomy patients had significantly better EPIC urinary irritation scores than brachytherapy patients (+4.16; p < 0.001). Conclusions: Relevant differences between treatment groups persisted after 2 years of follow-up. Radical prostatectomy had a considerable negative effect on sexual functioning and urinary continence. Three-dimensional conformal radiotherapy had a moderate negative impact on bowel

Retrospective Dosimetric Comparison of Low-Dose-Rate and Pulsed-Dose-Rate Intracavitary Brachytherapy Using a Tandem and Mini-Ovoids

International Nuclear Information System (INIS)

Mourtada, Firas; Gifford, Kent A.; Berner, Paula A.; Horton, John L.; Price, Michael J.; Lawyer, Ann A.; Eifel, Patricia J.

2007-01-01

The purpose of this study was to compare the dose distribution of Iridium-192 ( 192 Ir) pulsed-dose-rate (PDR) brachytherapy to that of Cesium-137 ( 137 Cs) low-dose-rate (LDR) brachytherapy around mini-ovoids and an intrauterine tandem. Ten patient treatment plans were selected from our clinical database, all of which used mini-ovoids and an intrauterine tandem. A commercial treatment planning system using AAPM TG43 formalism was used to calculate the dose in water for both the 137 Cs and 192 Ir sources. For equivalent system loadings, we compared the dose distributions in relevant clinical planes, points A and B, and to the ICRU bladder and rectal reference points. The mean PDR doses to points A and B were 3% ± 1% and 6% ± 1% higher than the LDR doses, respectively. For the rectum point, the PDR dose was 4% ± 3% lower than the LDR dose, mainly because of the 192 Ir PDR source anisotropy. For the bladder point, the PDR dose was 1% ± 4% higher than the LDR dose. We conclude that the PDR and LDR dose distributions are equivalent for intracavitary brachytherapy with a tandem and mini-ovoids. These findings will aid in the transfer from the current practice of LDR intracavitary brachytherapy to PDR for the treatment of gynecologic cancers

Comparison between conventional and three-dimensional conformal treatment planning for radiotherapy of cerebral tumors

International Nuclear Information System (INIS)

Caudrelier, J.M.; Auliard, A.; Sarrazin, T.; Gibon, D.; Coche-Dequeant, B.; Castelain, B.

2001-01-01

Comparison between conventional and three-dimensional conformal treatment planning for radiotherapy of cerebral tumors. Purpose. - We prospectively compared a conventional treatment planning (PT2D) and 3-dimensional conformal treatment planning (PT3D) for radiotherapy of cerebral tumours. Patients and methods.- Patients treated between 1/10/98 and 1/4/99 by irradiation for cerebral tumours were analysed. For each case, we planned PT2D using conventional orthogonal x-ray films, and afterward, PT3D using CT scan. Gross tumor volume, planning target volume and normal tissue volumes were defined. Dose was prescribed according to report 50 of the International Commission on Radiation Units and Measurements (ICRU). We compared surfaces of sagittal view targets defined on PT2D and PT3D and called them S2D and S3D, respectively. Irradiated volumes by 90% isodoses (VE-90%) and normal tissue volumes irradiated by 20, 50, 90% isodoses were calculated and compared using Student's paired t-test. Results. -There was a concordance of 84% of target surfaces defined on PT2D and PT3D. Percentages of target surface under- or-over defined by PT2D were 16 and 13% respectively. VE-90% was decreased by 15% (p = 0.07) with PT3D. Normal brain volume irradiated by 90% isodose was decreased by 27% with PT3D (p = 0.04). Conclusion.- For radiotherapy of cerebral tumors using only coplanar beams, PT3D leads to a reduction of normal brain tissue irradiated. We recommend PT3D for radiotherapy of cerebral tumors, particularly for low-grade or benign tumors (meningiomas, neuromas, etc.). (authors)

Online in vivo dosimetry in conformal radio therapies with MOSkin detectors

Energy Technology Data Exchange (ETDEWEB)

Gambarini, G.; Tenconi, C.; Mantaut, N. [Universita degli Studi di Milano, Department of Physics, Via Festa del Perdono 7, 20122 Milano (Italy); Carrara, M.; Borroni, M.; Pignoli, E. [Fondazione IRCCS Istituto Nazionale dei Tumori, Medical Physics Unit, Via Giuseppe Ponzio 44, Milan (Italy); Cutajar, D.; Petasecca, M.; Fuduli, I.; Lerch, M.; Rosenfeld, A. [University of Wollongong, Centre for Medical Radiation Physics, 2522 Wollongong, New South Wales (Australia)

2012-10-15

A novel MOSFET based dosimeter, the MOSkin, has been developed at the Centre for Medical Radiation Physics, University of Wollongong (Australia). This dosimeter is designed with suitable packaging that allows skin dose measurements at depths of 0.07 mm, as recommended by the ICRP. Initially proposed for real-time skin dose measurement, it is now studied for real-time in vivo dosimetry during high dose rate (Hdr) brachytherapy and intensity modulated radiotherapy. MOSkin detectors have shown good characteristics of reproducibility and linearity. Experiments performed with the {sup 192}Ir source of a Hdr brachytherapy facility have shown negligible energy response for photons from the Ir-192 source. The angular response is within the experimental error when used in a dual-MOSkin configuration. In this work, urethral dose measurements were performed in a tissue-equivalent phantom reproducing prostate brachytherapy treatments. The obtained urethral doses were compared to the dose values calculated by the treatment planning system and the discrepancy was found to be within 4%, showing that dual-MOSkin detectors can be profitably utilized for real-time in vivo dosimetry during a brachytherapy treatment. (Author)

Correlation of conventional simulation x-ray films and CT images for HDR-brachytherapy catheters reconstruction

International Nuclear Information System (INIS)

Rajendran, M.; Reddy, K.D.; Reddy, R.M.; Reddy, J.M.; Reddy, B.V.N.; Kiran Kumar; Gopi, S.; Dharaniraj; Janardhanan

2002-01-01

In order to plan a brachytherapy implant, it is imperative that implant reconstruction is done accurately. The purpose of this paper is to evaluate whether implant reconstruction done with transverse CT images is comparable to reconstruction done with conventional x-ray films

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

Energy Technology Data Exchange (ETDEWEB)

Owrangi, A; Jolly, S; Balter, J; Cao, Y; Young, L; Zhu, T; Prisciandaro, J [University of Michigan, Ann Arbor, MI (United States)

2014-06-01

Purpose: To evaluate the accuracy of MR-based vaginal brachytherapy source localization using an in-house MR-visible marker versus the alignment of an applicator model to MR images. Methods: Three consecutive patients undergoing vaginal HDR brachytherapy with a plastic cylinder were scanned with both CT and MRI (including T1- and T2- weighted images). An MR-visible source localization marker, consisting of a sealed thin catheter filled with either water (for T2 contrast) or Gd-doped water (for T1 contrast), was assembled shortly before scanning. Clinically, the applicator channel was digitized on CT with an x-ray marker. To evaluate the efficacy of MR-based applicator reconstruction, each MR image volume was aligned locally to the CT images based on the region containing the cylinder. Applicator digitization was performed on the MR images using (1) the MR visible marker and (2) alignment of an applicator surface model from Varian's Brachytherapy Planning software to the MRI images. Resulting source positions were compared with the original CT digitization. Results: Although the source path was visualized by the MR marker, the applicator tip proved difficult to identify due to challenges in achieving a watertight seal. This resulted in observed displacements of the catheter tip, at times >1cm. Deviations between the central source positions identified via aligning the applicator surface model to MR and using the xray marker on CT ranged from 0.07 – 0.19 cm and 0.07 – 0.20 cm on T1- weighted and T2-weighted images, respectively. Conclusion: Based on the current study, aligning the applicator model to MRI provides a practical, current approach to perform MR-based brachytherapy planning. Further study is needed to produce catheters with reliably and reproducibly identifiable tips. Attempts are being made to improve catheter seals, as well as to increase the viscosity of the contrast material to decrease fluid mobility inside the catheter.

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

Dosimetric effects of saline- versus water-filled balloon applicators for IORT using the model S700 electronic brachytherapy source.

Science.gov (United States)

Redler, Gage; Templeton, Alistair; Zhen, Heming; Turian, Julius; Bernard, Damian; Chu, James C H; Griem, Katherine L; Liao, Yixiang

The Xoft Axxent Electronic Brachytherapy System (Xoft, Inc., San Jose, CA) is a viable option for intraoperative radiation therapy (IORT) treatment of early-stage breast cancer. The low-energy (50-kVp) X-ray source simplifies shielding and increases relative biological effectiveness but increases dose distribution sensitivity to medium composition. Treatment planning systems typically assume homogenous water for brachytherapy dose calculations, including precalculated atlas plans for Xoft IORT. However, Xoft recommends saline for balloon applicator filling. This study investigates dosimetric differences due to increased effective atomic number (Z eff ) for saline (Z eff  = 7.56) versus water (Z eff  = 7.42). Balloon applicator diameters range from 3 to 6 cm. Monte Carlo N-Particle software is used to calculate dose at the surface (D s ) of and 1 cm away (D 1cm ) from the water-/saline-filled balloon applicator using a single dwell at the applicator center as a simple estimation of the dosimetry and multiple dwells simulating the clinical dose distributions for the atlas plans. Single-dwell plans show a 4.4-6.1% decrease in D s for the 3- to 6-cm diameter applicators due to the saline. Multidwell plans show similar results: 4.9% and 6.4% D s decrease, for 4-cm and 6-cm diameter applicators, respectively. For the single-dwell plans, D 1cm decreases 3.6-5.2% for the 3- to 6-cm diameter applicators. For the multidwell plans, D 1cm decreases 3.3% and 5.3% for the 4-cm and 6-cm applicators, respectively. The dosimetric effect introduced by saline versus water filling for Xoft balloon applicator-based IORT treatments is ∼5%. Users should be aware of this in the context of both treatment planning and patient outcome studies. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

AAPM and GEC-ESTRO guidelines for image-guided robotic brachytherapy: Report of Task Group 192

Energy Technology Data Exchange (ETDEWEB)

Podder, Tarun K., E-mail: tarun.podder@uhhospitals.org [Department of Radiation Oncology, University Hospitals, Case Western Reserve University, Cleveland, Ohio 44122 (United States); Beaulieu, Luc [Department of Radiation Oncology, Centre Hospitalier Univ de Quebec, Quebec G1R 2J6 (Canada); Caldwell, Barrett [Schools of Industrial Engineering and Aeronautics and Astronautics, Purdue University, West Lafayette, Indiana 47907 (United States); Cormack, Robert A. [Department of Radiation Oncology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Crass, Jostin B. [Department of Radiation Oncology, Vanderbilt University, Nashville, Tennessee 37232 (United States); Dicker, Adam P.; Yu, Yan [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States); Fenster, Aaron [Department of Imaging Research, Robarts Research Institute, London, Ontario N6A 5K8 (Canada); Fichtinger, Gabor [School of Computer Science, Queen’s University, Kingston, Ontario K7L 3N6 (Canada); Meltsner, Michael A. [Philips Radiation Oncology Systems, Fitchburg, Wisconsin 53711 (United States); Moerland, Marinus A. [Department of Radiotherapy, University Medical Center Utrecht, Utrecht, 3508 GA (Netherlands); Nath, Ravinder [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520 (United States); Rivard, Mark J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Salcudean, Tim [Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada); Song, Danny Y. [Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231 (United States); Thomadsen, Bruce R. [Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705 (United States)

2014-10-15

In the last decade, there have been significant developments into integration of robots and automation tools with brachytherapy delivery systems. These systems aim to improve the current paradigm by executing higher precision and accuracy in seed placement, improving calculation of optimal seed locations, minimizing surgical trauma, and reducing radiation exposure to medical staff. Most of the applications of this technology have been in the implantation of seeds in patients with early-stage prostate cancer. Nevertheless, the techniques apply to any clinical site where interstitial brachytherapy is appropriate. In consideration of the rapid developments in this area, the American Association of Physicists in Medicine (AAPM) commissioned Task Group 192 to review the state-of-the-art in the field of robotic interstitial brachytherapy. This is a joint Task Group with the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO). All developed and reported robotic brachytherapy systems were reviewed. Commissioning and quality assurance procedures for the safe and consistent use of these systems are also provided. Manual seed placement techniques with a rigid template have an estimated in vivo accuracy of 3–6 mm. In addition to the placement accuracy, factors such as tissue deformation, needle deviation, and edema may result in a delivered dose distribution that differs from the preimplant or intraoperative plan. However, real-time needle tracking and seed identification for dynamic updating of dosimetry may improve the quality of seed implantation. The AAPM and GEC-ESTRO recommend that robotic systems should demonstrate a spatial accuracy of seed placement ≤1.0 mm in a phantom. This recommendation is based on the current performance of existing robotic brachytherapy systems and propagation of uncertainties. During clinical commissioning, tests should be conducted to ensure that this level of accuracy is achieved. These tests

AAPM and GEC-ESTRO guidelines for image-guided robotic brachytherapy: Report of Task Group 192

International Nuclear Information System (INIS)

Podder, Tarun K.; Beaulieu, Luc; Caldwell, Barrett; Cormack, Robert A.; Crass, Jostin B.; Dicker, Adam P.; Yu, Yan; Fenster, Aaron; Fichtinger, Gabor; Meltsner, Michael A.; Moerland, Marinus A.; Nath, Ravinder; Rivard, Mark J.; Salcudean, Tim; Song, Danny Y.; Thomadsen, Bruce R.

2014-01-01

In the last decade, there have been significant developments into integration of robots and automation tools with brachytherapy delivery systems. These systems aim to improve the current paradigm by executing higher precision and accuracy in seed placement, improving calculation of optimal seed locations, minimizing surgical trauma, and reducing radiation exposure to medical staff. Most of the applications of this technology have been in the implantation of seeds in patients with early-stage prostate cancer. Nevertheless, the techniques apply to any clinical site where interstitial brachytherapy is appropriate. In consideration of the rapid developments in this area, the American Association of Physicists in Medicine (AAPM) commissioned Task Group 192 to review the state-of-the-art in the field of robotic interstitial brachytherapy. This is a joint Task Group with the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO). All developed and reported robotic brachytherapy systems were reviewed. Commissioning and quality assurance procedures for the safe and consistent use of these systems are also provided. Manual seed placement techniques with a rigid template have an estimated in vivo accuracy of 3–6 mm. In addition to the placement accuracy, factors such as tissue deformation, needle deviation, and edema may result in a delivered dose distribution that differs from the preimplant or intraoperative plan. However, real-time needle tracking and seed identification for dynamic updating of dosimetry may improve the quality of seed implantation. The AAPM and GEC-ESTRO recommend that robotic systems should demonstrate a spatial accuracy of seed placement ≤1.0 mm in a phantom. This recommendation is based on the current performance of existing robotic brachytherapy systems and propagation of uncertainties. During clinical commissioning, tests should be conducted to ensure that this level of accuracy is achieved. These tests

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.

Optimization of stereotactically-guided conformal treatment planning of sellar and parasellar tumors, based on normal brain dose volume histograms

International Nuclear Information System (INIS)

Perks, Julian R.; Jalali, Rakesh; Cosgrove, Vivian P.; Adams, Elizabeth J.; Shepherd, Stephen F.; Warrington, Alan P.; Brada, Michael

1999-01-01

Purpose: To investigate the optimal treatment plan for stereo tactically-guided conformal radiotherapy (SCRT) of sellar and parasellar lesions, with respect to sparing normal brain tissue, in the context of routine treatment delivery, based on dose volume histogram analysis. Methods and Materials: Computed tomography (CT) data sets for 8 patients with sellar- and parasellar-based tumors (6 pituitary adenomas and 2 meningiomas) have been used in this study. Treatment plans were prepared for 3-coplanar and 3-, 4-, 6-, and 30-noncoplanar-field arrangements to obtain 95% isodose coverage of the planning target volume (PTV) for each plan. Conformal shaping was achieved by customized blocks generated with the beams eye view (BEV) facility. Dose volume histograms (DVH) were calculated for the normal brain (excluding the PTV), and comparisons made for normal tissue sparing for all treatment plans at ≥80%, ≥60%, and ≥40% of the prescribed dose. Results: The mean volume of normal brain receiving ≥80% and ≥60% of the prescribed dose decreased by 22.3% (range 14.8-35.1%, standard deviation σ = 7.5%) and 47.6% (range 25.8-69.1%, σ 13.2%), respectively, with a 4-field noncoplanar technique when compared with a conventional 3-field coplanar technique. Adding 2 further fields, from 4-noncoplanar to 6-noncoplanar fields reduced the mean normal brain volume receiving ≥80% of the prescribed dose by a further 4.1% (range -6.5-11.8%, σ = 6.4%), and the volume receiving ≥60% by 3.3% (range -5.5-12.2%, σ = 5.4%), neither of which were statistically significant. Each case must be considered individually however, as a wide range is seen in the volume spared when increasing the number of fields from 4 to 6. Comparing the 4- and 6-field noncoplanar techniques to a 30-field conformal field approach (simulating a dynamic arc plan) revealed near-equivalent normal tissue sparing. Conclusion: Four to six widely spaced, fixed-conformal fields provide the optimum class solution

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

Energy Technology Data Exchange (ETDEWEB)

Kim, Yeon-Joo; Kim, Joo-Young [National Cancer Center, Proton Therapy Center, Goyang (Korea, Republic of); National Cancer Center, Center for Uterine Cancer, Goyang (Korea, Republic of); Kim, Youngkyong; Lim, Young Kyung; Jeong, Jonghwi [National Cancer Center, Proton Therapy Center, Goyang (Korea, Republic of); Jeong, Chiyoung [National Cancer Center, Proton Therapy Center, Goyang (Korea, Republic of); University of Ulsan College of Medicine, Department of Radiation Oncology, Asan Medical Center, Seoul (Korea, Republic of); Kim, Meyoung [National Cancer Center, Proton Therapy Center, Goyang (Korea, Republic of); Dongnam Inst. of Radiology and Medical Sciences, Research center, Busan (Korea, Republic of); Lim, Myong Cheol; Seo, Sang-Soo; Park, Sang-Yoon [National Cancer Center, Center for Uterine Cancer, Goyang (Korea, Republic of)

2016-12-15

The purpose of this work was to identify prognostic factors for survival after magnetic resonance image (MRI)-guided brachytherapy combined with external beam radiotherapy for cervical cancer. External beam radiotherapy of 45-50.4 Gy was delivered by either three-dimensional conformal radiotherapy or helical tomotherapy. Patients also received high-dose-rate MRI-guided brachytherapy of 5 Gy in 6 fractions. We analyzed 128 patients with International Federation of Gynecology and Obstetrics stage IB-IVB cervical cancer who underwent MRI-guided brachytherapy. Most patients (96 %) received concurrent chemotherapy. Pelvic lymph node metastases and para-aortic lymphadenopathies were found in 62 % and 14 % of patients, respectively. The median follow-up time was 44 months. Complete remission was achieved in 119 of 128 patients (93 %). The 5-year local recurrence-free, cancer-specific, and overall survival rates were 94, 89, and 85 %, respectively. Negative pelvic lymphadenopathy, gross tumor volume (GTV) dose covering 90 % of the target (GTV D90) of >110 Gy, and treatment duration ≤56 days were associated with better overall survival in univariate analyses. Multivariable analysis showed that GTV D90 of >110 Gy and treatment duration ≤56 days were possibly associated with overall survival with near-significant P-values of 0.062 and 0.073, respectively. The outcome of MRI-guided brachytherapy combined with external beam radiotherapy in patients with cervical cancer was excellent. GTV D90 of >110 Gy and treatment duration ≤56 days were potentially associated with overall survival. (orig.) [German] Ziel der Arbeit war es, prognostische Faktoren nach magnetresonanztomographisch (MRT-)gesteuerter Brachytherapie in Verbindung mit externer Strahlentherapie fuer Gebaermutterhalskrebs zu identifizieren. Externe Strahlentherapie von 45-50,4 Gy erfolgte entweder mittels dreidimensionaler konformaler Strahlentherapie oder helikaler Tomotherapie. Die Patientinnen erhielten auch

'Homogeneity in brachytherapy' - Dummy run experience in Belgium

International Nuclear Information System (INIS)

Methords

1996-01-01

Purpose: The homogeneity of brachytherapy treatments in Belgium was appreciated through a dummy run with two fictive patients. Materiel and Methods: All members of the Belgian Brachytherapy Board received last year a questionnaire about treatment technique, technical approach, dosimetry and treatment planning, for 2 selected clinical histories. Case 1: T1 G1 NO MO - SCC of the lateral border of the mobile tongue (dimensions: 12x10x5mm). Case 2: T1 G1 NO MO - SCC of the lateral side of the nose (10x12x3mm). Results: 10 members out of 14 from the Belgian Brachytherapy Board returned their questionnaire. Little variation has been observed regarding treatment technique, technical approach (H and N: hairpins or loops, skin: plastic tubes), dose (60-65 Gy), activity of Ir-192 (1-2 mCi/cm), definition of Gross Tumor Volume and dosimetry (Paris System). On the contrary, a large difference was observed in the definition of the Clinical Target Volume and the Treated Volume. Despite of this large difference, the ratio treated volume on clinical target volume was always satisfactory (1,2 for skin cancer - 2 for H and N cancer), indicating that the treatment was well adapted to the Clinical Target Volume in all but 1 instance. Variations of a factor 2 in the dose rate of irradiation were tolerated (40-80 cGy/h). Conclusion: Rigid guidelines are mostly followed by the responders concerning dose, dose prescription and implantation techniques. Large variations are encountered concerning safety margins (Clinical Target definition) and dose rate

Tracking brachytherapy sources using emission imaging with one flat panel detector

International Nuclear Information System (INIS)

Song Haijun; Bowsher, James; Das, Shiva; Yin Fangfang

2009-01-01

This work proposes to use the radiation from brachytherapy sources to track their dwell positions in three-dimensional (3D) space. The prototype device uses a single flat panel detector and a BB tray. The BBs are arranged in a defined pattern. The shadow of the BBs on the flat panel is analyzed to derive the 3D coordinates of the illumination source, i.e., the dwell position of the brachytherapy source. A kilovoltage x-ray source located 3.3 m away was used to align the center BB with the center pixel on the flat panel detector. For a test plan of 11 dwell positions, with an Ir-192 high dose rate unit, one projection was taken for each dwell point, and locations of the BB shadows were manually identified on the projection images. The 3D coordinates for the 11 dwell positions were reconstructed based on two BBs. The distances between dwell points were compared with the expected values. The average difference was 0.07 cm with a standard deviation of 0.15 cm. With automated BB shadow recognition in the future, this technique possesses the potential of tracking the 3D trajectory and the dwell times of a brachytherapy source in real time, enabling real time source position verification.

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.

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.

Bladder radiotherapy treatment: A retrospective comparison of 3-dimensional conformal radiotherapy, intensity-modulated radiation therapy, and volumetric-modulated arc therapy plans

Energy Technology Data Exchange (ETDEWEB)

Pasciuti, Katia, E-mail: k.pasciuti@virgilio.it [Department of Radiotherapy Physics, Royal Free Hospital, London (United Kingdom); Kuthpady, Shrinivas [Department of Radiotherapy, Royal Free Hospital, London (United Kingdom); Anderson, Anne; Best, Bronagh [Department of Radiotherapy Physics, Royal Free Hospital, London (United Kingdom); Waqar, Saleem; Chowdhury, Subhra [Department of Radiotherapy, Royal Free Hospital, London (United Kingdom)

2017-04-01

To examine tumor's and organ's response when different radiotherapy plan techniques are used. Ten patients with confirmed bladder tumors were first treated using 3-dimensional conformal radiotherapy (3DCRT) and subsequently the original plans were re-optimized using the intensity-modulated radiation treatment (IMRT) and volumetric-modulated arc therapy (VMAT)-techniques. Targets coverage in terms of conformity and homogeneity index, TCP, and organs' dose limits, including integral dose analysis were evaluated. In addition, MUs and treatment delivery times were compared. Better minimum target coverage (1.3%) was observed in VMAT plans when compared to 3DCRT and IMRT ones confirmed by a statistically significant conformity index (CI) results. Large differences were observed among techniques in integral dose results of the femoral heads. Even if no statistically significant differences were reported in rectum and tissue, a large amount of energy deposition was observed in 3DCRT plans. In any case, VMAT plans provided better organs and tissue sparing confirmed also by the normal tissue complication probability (NTCP) analysis as well as a better tumor control probability (TCP) result. Our analysis showed better overall results in planning using VMAT techniques. Furthermore, a total time reduction in treatment observed among techniques including gantry and collimator rotation could encourage using the more recent one, reducing target movements and patient discomfort.

Experiences with alanine dosimetry in afterloading brachytherapy

International Nuclear Information System (INIS)

Eberhardt, H.-J.; Gohs, U.

1996-01-01

the mucosal surface. The dose measurements as well were performed in each single radiation therapy session as cumulatively during the whole course. Measurements of absorbed brachytherapy doses were made on 5 patients. The good agreement between the dosages determined by alanine/ESR dosimetry and those predicted by treatment planning indicate that this technique can be used for quality assurance in brachytherapy

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...

SU-F-T-44: A Comparison of the Pre-Plan, Intra-Operative Plan, and Post-Implant Dosimetry for a Prostate Implant Case Using Prefabricated Linear Polymer-Encapsulated Pd-103

International Nuclear Information System (INIS)

Sheu, R; Powers, A; McGee, H; Stock, R; Lo, Y

2016-01-01

Purpose: To investigate the reproducibility and limitations of Pd-103 prostate brachytherapy using fixed length linear sources (CivaString). Methods: An LDR prostate brachytherapy case which was preplanned on MR images with prefabricated linear polymer-encapsulated Pd-103 sources (CivaString) was studied and compared with ultrasound based intra-operative planning and CT based post-implant dosimetry. We evaluated the following parameters among the three studies: prostate geometry (volume and cross sectional area), needle position and alignment deviations, and dosimetry parameters (D90). Results: The prostate volumes and axial cross sectional areas at center of prostate were measured as 41.8, 39.3 and 36.8 cc, and 14.9, 14.3, and 11.3 respectively on pre-plan MR, inter-op US, and post-implant CT studies. The deviation of prostate volumes and axial cross sectional areas measured on pre-planning MR and intra-operative US were within 5%. 17 out of 19 pre-planned needles were positioned within 5mm (the template grid size). One needle location was adjusted intra-operatively and another needle was removed due to proximity to urethra. The needle pathways were not always parallel to the trans-rectal probe due to the flexibility of CivaString. The angle of deviation was up to 10 degrees. Two pairs of needles were exchanged to better fit the length of prostate at the time of implant. This resulted in a prostate D90 of 153.8 Gy (124%) and 131.4 Gy (106.7%) for intra-op and PID respectively. Conclusion: Preplanning is a necessary part of implants performed with prefabricated linear polymer sources. However, as is often the case, there were real-time deviations from the pre-plan. Intra-op planning provides the ability conform to anatomy at the time of implant. Therefore, we propose to develop a systematic way to order extra strings of different length to provide the flexibility to perform intra-operative planning with fixed length strands.

SU-F-T-44: A Comparison of the Pre-Plan, Intra-Operative Plan, and Post-Implant Dosimetry for a Prostate Implant Case Using Prefabricated Linear Polymer-Encapsulated Pd-103

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Sheu, R; Powers, A; McGee, H; Stock, R; Lo, Y [Mount Sinai Medical Center, New York, NY (United States)

2016-06-15

Purpose: To investigate the reproducibility and limitations of Pd-103 prostate brachytherapy using fixed length linear sources (CivaString). Methods: An LDR prostate brachytherapy case which was preplanned on MR images with prefabricated linear polymer-encapsulated Pd-103 sources (CivaString) was studied and compared with ultrasound based intra-operative planning and CT based post-implant dosimetry. We evaluated the following parameters among the three studies: prostate geometry (volume and cross sectional area), needle position and alignment deviations, and dosimetry parameters (D90). Results: The prostate volumes and axial cross sectional areas at center of prostate were measured as 41.8, 39.3 and 36.8 cc, and 14.9, 14.3, and 11.3 respectively on pre-plan MR, inter-op US, and post-implant CT studies. The deviation of prostate volumes and axial cross sectional areas measured on pre-planning MR and intra-operative US were within 5%. 17 out of 19 pre-planned needles were positioned within 5mm (the template grid size). One needle location was adjusted intra-operatively and another needle was removed due to proximity to urethra. The needle pathways were not always parallel to the trans-rectal probe due to the flexibility of CivaString. The angle of deviation was up to 10 degrees. Two pairs of needles were exchanged to better fit the length of prostate at the time of implant. This resulted in a prostate D90 of 153.8 Gy (124%) and 131.4 Gy (106.7%) for intra-op and PID respectively. Conclusion: Preplanning is a necessary part of implants performed with prefabricated linear polymer sources. However, as is often the case, there were real-time deviations from the pre-plan. Intra-op planning provides the ability conform to anatomy at the time of implant. Therefore, we propose to develop a systematic way to order extra strings of different length to provide the flexibility to perform intra-operative planning with fixed length strands.

BED-Volume histograms calculation for routine clinical dosimetry in brachytherapy

International Nuclear Information System (INIS)

Galelli, M.; Feroldi, P.

1995-01-01

The consideration of volumes is essential in Brachytherapy clinical dosimetry (I.C.R.U). Indeed, several indices, all based on dose-volume histograms (DVHs), have been designed in order to evaluate: before the therapy the volumetric quality of different possible implant geometries; during the therapy the consistency of the real and the previsional implants. Radiobiological evaluations, considering the dose deposition temporal pattern of treatment, can be usefully added to dosimetric calculations, to compare different treatment schedules. The Linear-Quadratic model is the most used: radiobiological modelisation and Biologically Effective Dose (BED) is principal related dosimetric quantity. Therefore, the consideration of BED-volume histogram (BED-VHs) is a straightforward extension of DVHs. In practice, BED-VHs can help relative comparisons and optimisations in treatment planning when combined to dose-volume histograms. Since 1994 the dosimetric calculations for all the gynecological brachytherapy treatments are performed considering also DVHs and BED-VHs. In this presentation we show the methods of BEDVHs calculation, together with some typical results

Importance of the neutrons kerma coefficient in the planning of Brachytherapy treatments with Cf-252 sources

International Nuclear Information System (INIS)

Paredes G, L.; Balcazar G, M.; Azorin N, J.; Francois L, J.L.

2006-01-01

The Cf-252 is a fast neutrons emitting radioisotope by spontaneous fission that can be used as sealed source in medicine applications, industry and research. Commercially its offer sources of different sizes, compact and with a fast neutrons emission of the order of 10 6 n/s-μg and an energy spectra that presents respectively maxim and average energy in 2.1 MeV and 0.7 MeV. In medicine new applications are being developed for the treatment of patient with hypoxic and voluminous tumors, where the therapy with photons has not given positive results, as well as for the protocols of therapy treatment by boron neutron capture, where very small sources of Cf-252 will be used with the interstitial brachytherapy technique of high and low dose rate. In this work an analysis of how the small differences that exist in the elementary composition of 4 wicked tumors, 4 ICRU healthy tissues and 3 substitute materials of ICRU tissue used in dosimetry are presented, its generate changes in the neutrons kerma coefficient in function of the energy and consequently in the absorbed dose in the interval of 11 eV to 29 MeV. These differences can produce maximum variations of the neutron kerma coefficients ratio for E n > 1 keV of the one: 15% tumor/ICRU guest healthy tissue, 12% ICRU tumor/muscle, 12% ICRU healthy tissues ICRU/ICRU muscle, 22% substitutes tissue/tumor and 22% ICRU substitutes tissue/muscle. Also, it was found that the average value of the neutrons kerma coefficient for the 4 wicked tumors is from 6% to 7% smaller that the average value for the soft tissue in the interval energy of interest for therapy with fast neutrons with E n > 1 MeV. These results have a special importance during the planning process of brachytherapy treatments with sources of 252 Cf, to optimize and to individualize the patients treatments. (Author)

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

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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

Matched-pair analysis and dosimetric variations of two types of software for interstitial permanent brachytherapy for prostate cancer

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Ishiyama, Hiromichi, E-mail: hishiyam@kitasato-u.ac.jp [Department of Radiology, Kitasato University School of Medicine, Sagamihara, Kanagawa (Japan); Nakamura, Ryuji [Department of Radiology, Iwate Medical University, Morioka, Iwate (Japan); Satoh, Takefumi [Department of Urology, Kitasato University School of Medicine, Sagamihara, Kanagawa (Japan); Tanji, Susumu [Department of Urology, Iwate Medical University, Morioka, Iwate (Japan); Teh, Bin S. [Department of Radiation Oncology, The Methodist Hospital, Houston, TX (United States); Uemae, Mineko [Division of Radiation Oncology, Kitasato University Hospital, Sagamihara, Kanagawa (Japan); Baba, Shiro [Department of Urology, Kitasato University School of Medicine, Sagamihara, Kanagawa (Japan); Hayakawa, Kazushige [Department of Radiology, Kitasato University School of Medicine, Sagamihara, Kanagawa (Japan)

2012-04-01

The purpose of this study was to determine whether identical dosimetric results could be achieved using different planning software for permanent interstitial brachytherapy for prostate cancer. Data from 492 patients treated with brachytherapy were used for matched-pair analysis. Interplant and Variseed were used as software for ultrasound-based treatment planning. Institution, neoadjuvant hormonal therapy, prostate volume, and source strength were used for factors to match the 2 groups. The study population comprised of 126 patients with treatment planning using Interplant software and 127 matched patients using Variseed software. Dosimetric results were compared between the 2 groups. The Variseed group showed significantly higher values for dose covering 90% of prostate volume (pD90), prostate volume covered by 150% of prescription dose (pV150), and dose covering 30% of the urethra (uD30) compared with the Interplant group. Our results showed that use of different software could lead to different dosimetric results, which might affect the clinical outcomes.

Prostate brachytherapy - discharge

Science.gov (United States)

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.

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.

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

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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)

Critical Organ Preservation in Reirradiation Brachytherapy by Injectable Spacer

International Nuclear Information System (INIS)

Kishi, Kazushi; Sonomura, Tetsuo; Shirai, Shintaro; Sato, Morio; Tanaka, Kayo

2009-01-01

Purpose: This case series study evaluated the feasibility and effectiveness of an interstitial high-dose rate brachytherapy (HDR-BT) procedure combined with an at-risk organ-sparing procedure. Methods and Materials: Thirty patients who were scheduled for reirradiation treatment for recurrent cancer after receiving a median dose of 60 Gy (range, 44-70 Gy) in 2-Gy fractions of previous external beam treatment were enrolled. Thirteen patients had lesions in the head and neck, and other lesions were located in the axilla, skeleton, breast, pelvis, and abdominal wall. Chief complaints included local masses (for 25) and refractory pain (for 21). After high-dose rate brachytherapy applicator needle implantation, an optimal CT-based three-dimensional brachytherapy plan was created with a virtual at-risk organ shift from the target. According to the plan, hyaluronic acid gel was injected to maintain the shift during irradiation. The prescribed dose was the result of an individualized tradeoff between target dose and at-risk organ dose, to avoid serious complications. A single-fraction dose of 18.0 Gy (median, equivalent to 75.6 Gy at an α/β value of 3; range, 16-20 Gy) was applied to the tumor. Results: The at-risk organ dose decreased from 9.1 ± 0.9 Gy to 4.4 ± 0.4 Gy (mean ± standard deviation, p < 0.01), and the normal tissue complication probability decreased from 60.8% ± 12.6% to 16.1% ± 19.8% (p < 0.01). The shift effect lasted at least 4 hours and disappeared gradually. Distinct tumor shrinkage in 20 of 21 eligible patients, including tumor disappearance in 6 patients, pain reduction in 18 of 21 eligible patients, and no unexpected late toxicity greater than grade 2 were observed during the 19.5-month observation period. Conclusions: This at-risk organ-sparing preservation procedure may provide a safe and efficient reirradiation treatment.

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

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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

Ultrasound-guided interstitial brachytherapy in the treatment of advanced vaginal recurrences from cervical and endometrial carcinoma

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Weitmann, H.D.; Knocke, T.H.; Waldhaeusl, C.; Poetter, R. [Dept. of Radiotherapy and Radiobiology, Medical Univ. of Vienna (Austria)

2006-02-01

Background: in advanced vaginal recurrences of cervical and endometrial carcinomas therapeutic options are rare because of preceding therapy. Patients and methods: 23 patients developing advanced vaginal recurrences of cervical and endometrial carcinomas were included. 15 patients started with external-beam therapy to the pelvis and eight patients after preceding radiotherapy underwent brachytherapy alone. All patients had ultrasound-guided implantation of transvaginal or transperineal interstitial needles for brachytherapy. Median prescribed total dose was 64 Gy. Results: 18 patients (78%) achieved complete remission. Six patients are alive without tumor and one with tumor after a median follow-up of 64 months. 14 patients died of tumor and two of intercurrent disease. 5-year disease-specific survival and local control rate were 43% and 47%, respectively, in patients with complete remission. Univariate analysis found time to relapse > 2 years, initial diameter {<=} 4 cm, initial volume < 15 cm{sup 3}, no extension to the pelvic side wall, volume before brachytherapy < 7.5 cm{sup 3}, brachytherapy coverage index > 0.8, and prescribed total dose > 64 Gy being positive predictors for local control and survival. Conclusion: the use of ultrasound guidance for placement of interstitial needles in template-based brachytherapy of advanced recurrent gynecologic malignancies is a feasible, safe, and cheap method with encouraging results. Today, ultrasound imaging can be also used to some extent for treatment planning which requires further development. Patient- and treatment-related prognostic factors can be defined. (orig.)

Quality control in pulsed dose rate brachytherapy; Controle de qualite en curietherapie de debit de dose pulse

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Metayer, Y.; Brunaud, C.; Peiffert, D. [Centre Alexis-Vautrin, Unite de Radiophysique, 54 - Vandoeuvre-les-Nancy (France); Meyer, P. [Centre Paul-Strauss, 67 - Strasbourg (France)

2009-07-15

A prospective multicenter study (P.D.R.) was leaded on pulsed dose rate brachytherapy over 2 years (2005/2006) in 20 French centres, as part of a programme entitled (Support for the innovative and expensive techniques) S.t.i.c.-P.D.R. and supported by the French ministry of health. Eight hundred and fifty patients were treated for cervix carcinoma with 2D classic or 3D innovative brachytherapy (425 in each arm). The main objectives of this study were to assess the cost of P.D.R. brachytherapy with dose optimization compared to traditional treatments, and to evaluate the complications and local control. A joint programme of quality control was established by the physicists of the different centres, concerning the software treatment planning, the source replacement, the projector and the technical parameters of the course of patient treatment. This technical note lists these controls, and their frequency. (authors)

Dosimetric evaluation of PLATO and Oncentra treatment planning systems for High Dose Rate (HDR) brachytherapy gynecological treatments

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Singh, Hardev; De La Fuente Herman, Tania; Showalter, Barry; Thompson, Spencer J.; Syzek, Elizabeth J.; Herman, Terence; Ahmad, Salahuddin [Department of Radiation Oncology, Peggy and Charles Stephenson Oklahoma Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104 (United States)

2012-10-23

This study compares the dosimetric differences in HDR brachytherapy treatment plans calculated with Nucletron's PLATO and Oncentra MasterPlan treatment planning systems (TPS). Ten patients (1 T1b, 1 T2a, 6 T2b, 2 T4) having cervical carcinoma, median age of 43.5 years (range, 34-79 years) treated with tandem and ring applicator in our institution were selected retrospectively for this study. For both Plato and Oncentra TPS, the same orthogonal films anterior-posterior (AP) and lateral were used to manually draw the prescription and anatomical points using definitions from the Manchester system and recommendations from the ICRU report 38. Data input for PLATO was done using a digitizer and Epson Expression 10000XL scanner was used for Oncentra where the points were selected on the images in the screen. The prescription doses for these patients were 30 Gy to points right A (RA) and left A (LA) delivered in 5 fractions with Ir-192 HDR source. Two arrangements: one dwell position and two dwell positions on the tandem were used for dose calculation. The doses to the patient points right B (RB) and left B (LB), and to the organs at risk (OAR), bladder and rectum for each patient were calculated. The mean dose and the mean percentage difference in dose calculated by the two treatment planning systems were compared. Paired t-tests were used for statistical analysis. No significant differences in mean RB, LB, bladder and rectum doses were found with p-values > 0.14. The mean percent difference of doses in RB, LB, bladder and rectum are found to be less than 2.2%, 1.8%, 1.3% and 2.2%, respectively. Dose calculations based on the two different treatment planning systems were found to be consistent and the treatment plans can be made with either system in our department without any concern.

Accuracy Evaluation of Oncentra™ TPS in HDR Brachytherapy of Nasopharynx Cancer Using EGSnrc Monte Carlo Code

Science.gov (United States)

Hadad, K.; Zohrevand, M.; Faghihi, R.; Sedighi Pashaki, A.

2015-01-01

Background HDR brachytherapy is one of the commonest methods of nasopharyngeal cancer treatment. In this method, depending on how advanced one tumor is, 2 to 6 Gy dose as intracavitary brachytherapy is prescribed. Due to high dose rate and tumor location, accuracy evaluation of treatment planning system (TPS) is particularly important. Common methods used in TPS dosimetry are based on computations in a homogeneous phantom. Heterogeneous phantoms, especially patient-specific voxel phantoms can increase dosimetric accuracy. Materials and Methods In this study, using CT images taken from a patient and ctcreate-which is a part of the DOSXYZnrc computational code, patient-specific phantom was made. Dose distribution was plotted by DOSXYZnrc and compared with TPS one. Also, by extracting the voxels absorbed dose in treatment volume, dose-volume histograms (DVH) was plotted and compared with Oncentra™ TPS DVHs. Results The results from calculations were compared with data from Oncentra™ treatment planning system and it was observed that TPS calculation predicts lower dose in areas near the source, and higher dose in areas far from the source relative to MC code. Absorbed dose values in the voxels also showed that TPS reports D90 value is 40% higher than the Monte Carlo method. Conclusion Today, most treatment planning systems use TG-43 protocol. This protocol may results in errors such as neglecting tissue heterogeneity, scattered radiation as well as applicator attenuation. Due to these errors, AAPM emphasized departing from TG-43 protocol and approaching new brachytherapy protocol TG-186 in which patient-specific phantom is used and heterogeneities are affected in dosimetry. PMID:25973408

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)