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Prostate brachytherapy

J Kranz, G Maurer, U Maurer, O Deserno, S Schulte, J Steffens
BACKGROUND: A urethral stricture is a scar of the urethral epithelium which can cause obstructive voiding dysfunction with consequential damage of the upper urinary tract. Almost 45% of all strictures are iatrogenic; they develop in 2-9% of patients after radical prostatectomy, but can also occur after prostate cancer radiotherapy. This study provides 5‑year data of a certified prostate cancer center (PKZ) in terms of urethral strictures. MATERIALS AND METHODS: Between 01/2008 and 12/2012 a total of 519 men were irradiated for prostate cancer (LDR and HDR brachytherapy as well as external beam radiation)...
January 19, 2017: Der Urologe. Ausg. A
Jingfei Ma, Marinus A Moerland, Aradhana M Venkatesan, Tharakeswara K Bathala, Rajat J Kudchadker, Kristy K Brock, Steven J Frank
PURPOSE: The purpose of this work is to present a brief review of MRI physics principles pertinent to prostate brachytherapy, and a summary of our experience in optimizing protocols for prostate brachytherapy applications. METHODS AND MATERIALS: We summarized essential MR imaging characteristics and their interplays that need to be considered for prostate brachytherapy applications. These include spatial resolution, signal-to-noise ratio, image contrast, artifacts, geometric distortion, specific absorption rate, and total scan time...
January 4, 2017: Brachytherapy
Patrick W McLaughlin, Adam L Liss, Paul L Nguyen, Dean G Assimos, Anthony V D'Amico, Alexander R Gottschalk, Gary S Gustafson, Sameer R Keole, Stanley L Liauw, Shane Lloyd, Benjamin Movsas, Bradley R Prestidge, Timothy N Showalter, Al V Taira, Neha Vapiwala, Brian J Davis
PURPOSE: To present the most updated American College of Radiology consensus guidelines formed from an expert panel on treatment of locally advanced, high-risk prostate cancer METHODS:: The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios...
January 4, 2017: American Journal of Clinical Oncology
E Mok Tsze Chung, H Safigholi, A Nicolae, M Davidson, A Ravi, D Aleman, W Song
PURPOSE: The effectiveness of using a combination of three sources, (60) Co, (192) Ir and (169) Yb, is analyzed. Different combinations are compared against a single (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...
June 2016: Medical Physics
J Prisciandaro
: 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...
June 2016: Medical Physics
A Babier, C Joshi
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...
June 2016: Medical Physics
K Tamura, F Araki, T Ohno
PURPOSE: To investigate the difference of dose distributions with/without the effect of inter-seed attenuation and tissue compositions in prostate (125) I brachytherapy dose calculations, using Monte Carlo simulations of Particle and Heavy Ion Transport code System (PHITS). METHODS: The dose distributions in (125) I prostate brachytherapy were calculated using PHITS for non-simultaneous and simultaneous alignments of STM1251 sources in water or prostate phantom for six patients...
June 2016: Medical Physics
O Craciunescu
: The greater use of magnetic resonance imaging (MR) in brachytherapy, for both image based planning and image guided procedures, presents a number of challenges for the physicist involved. MR is widely acknowledged as the imaging modality of choice to appreciate a patient's pelvic anatomy and is thus used more often for brachytherapy of gynecologic and prostate cancers. Incorporating MR in brachytherapy treatments requires changes throughout the clinical workflow from implantation through target definition, applicator digitization and post-implant evaluation...
June 2016: Medical Physics
M Borot de Battisti, B Denis de Senneville, M Maenhout, G Hautvast, D Binnekamp, J J W Lagendijk, M Van Vulpen, M A Moerland
PURPOSE: This study assesses the potential of Fiber Bragg Grating (FBG)-based sensing for real-time needle (including catheter or tube) tracking during MR-guided HDR brachytherapy. METHODS: The proposed FBG-based sensing tracking approach involves a MR-compatible stylet composed of three optic fibers with nine sets of embedded FBG sensors each. When the stylet is inserted inside the lumen of the needle, the FBG sensing system can measure the needle's deflection...
June 2016: Medical Physics
J Roper, B Ghavidel, V Chanyavanich, K Godette, E Schreibmann
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...
June 2016: Medical Physics
C Lin, Y Tsai, H Lin, K Chuang, C Chiang
PURPOSE: To monitor the activity distribution and needle position during and after implantation in operating rooms. METHODS: Simulation studies were conducted to assess the feasibility of measurement activity distribution and seed localization using the DuPECT system. The system consists of a LaBr3-based probe and planar detection heads, a collimation system, and a coincidence circuit. The two heads can be manipulated independently. Simplified Yb-169 brachytherapy seeds were used...
June 2016: Medical Physics
F Hueso-Gonzalez, J Vijande, F Ballester, J Perez-Calatayud, F Siebert
PURPOSE: Tissue heterogeneities and calcifications have significant impact on the dosimetry of low energy brachytherapy (BT). RayStretch is an analytical algorithm developed in our institution to incorporate heterogeneity corrections in LDR prostate brachytherapy. The aim of this work is to study its application in clinical cases by comparing its predictions with the results obtained with TG-43 and Monte Carlo (MC) simulations. METHODS: A clinical implant (71 I-125 seeds, 15 needles) from a real patient was considered...
June 2016: Medical Physics
R Sheu, A Powers, H McGee, R Stock, Y Lo
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)...
June 2016: Medical Physics
S Mashouf, H Safigholi, T Merino, A Soliman, A Ravi, G Morton, W Song
PURPOSE: There is strong evidence relating post-implant dosimetry for low-dose-rate (LDR) prostate seed brachytherapy to local control rates. The delineation of the prostate on CT images, however, represents a challenge due to the lack of soft tissue contrast in order to identify the prostate borders. This study aims at quantifying the sensitivity of clinically relevant dosimetric parameters to uncertainty in the contouring of prostate. METHODS: CT images, post-op plans and contours of a cohort of patients (n=43) (low risk=55...
June 2016: Medical Physics
A Soliman, R Nosrati, H Safigholi, A Owrangi, G Morton, W Song
PURPOSE: To propose a new method that provides a positive contrast visualization of the prostate brachytherapy seeds using the phase information from MR images. Additionally, the feasibility of using the processed phase information to distinguish seeds from calcifications is explored. METHODS: A gel phantom was constructed using 2% agar dissolved in 1 L of distilled water. Contrast agents were added to adjust the relaxation times. Four iodine-125 (Eckert & Ziegler SML86999) dummy seeds were placed at different orientations with respect to the main magnetic field (B0)...
June 2016: Medical Physics
A Nicolae, L Lu, G Morton, H Chung, J Helou, M Al Hanaqta, A Loblaw, E Heath, A Ravi
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)...
June 2016: Medical Physics
J Cheung, J Cunha, A Sudhyadhom, C McGuinness, M Roach, M Descovich
PURPOSE: Robotic radiosurgery is a salvage treatment option for patients with recurrent prostate cancer. We explored the feasibility of tracking the bolus of permanent prostate implants (PPI) using image recognition software optimized to track spinal anatomy. METHODS: Forty-five inert iodine seeds were implanted into a gelatin-based prostate phantom. Four superficial gold seeds were inserted to provide ground-truth alignment. A CT scan of the phantom (120 kVp, 1 mm slice thickness) was acquired and a single-energy iterative metal artifact reduction (MAR) algorithm was used to enhance the quality of the DRR used for tracking...
June 2016: Medical Physics
A Likhacheva, E Grade, A Sadeghi, T Sokolowski
PURPOSE: The purpose of this study is to compare dosimetric calculations using traditional TG-43 formalism and Oncentra Brachy Advanced Collapsed cone Engine (ACE) TG-186 calculation algorithm in clinical setting. METHODS: We analyzed dosimetry of four patients treated with accelerated partial breast irradiation using a multi-channel intracavitary device (SAVI). All patients were treated to 34 Gy in 10 fractions using a high-dose-rate (192) Ir source. The plans were designed and treated using the TG-43 model...
June 2016: Medical Physics
Z Chang
: 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...
June 2016: Medical Physics
H Xu, S Lee, T Diwanji, P Amin, K Krudys, M Guerrero
PURPOSE: In our clinic, the planning CT is used for definitive and boost low-dose-rate (LDR) brachytherapy treatments to determine the ultrasound volume in the operating room (OR) at the time of the implant. While the CT overestimation of OR volume is known, a larger estimation discrepancy has been observed for boost treatments. A possible reason is the prostate size reduction during EBRT for boost patients. Since cone-beam CT (CBCT) is often used as routine imaging guidance of EBRT, this prostate volume change may be captured...
June 2016: Medical Physics
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