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Observer preference of artificial intelligence-generated versus clinical prostate contours for ultrasound-based high dose rate brachytherapy. Med Phys 2023; 50:5935-5943. [PMID: 37665729 DOI: 10.1002/mp.16716] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 07/21/2023] [Accepted: 08/23/2023] [Indexed: 09/06/2023] Open
Abstract
BACKGROUND For trans-rectal ultrasound (TRUS)-based high dose rate (HDR) prostate brachytherapy, prostate contouring can be challenging due to artifacts from implanted needles, bleeding, and calcifications. PURPOSE To evaluate the geometric accuracy and observer preference of an artificial intelligence (AI) algorithm for generating prostate contours on TRUS images with implanted needles. METHODS We conducted a retrospective study of 150 patients, who underwent HDR brachytherapy. These patients were randomly divided into training (104), validation (26) and testing (20) sets. An AI algorithm was trained/validated utilizing the TRUS image and reference (clinical) contours. The algorithm then provided contours for the test set. For evaluation, we calculated the Dice coefficient between AI and reference prostate contours. We then presented AI and reference contours to eight clinician observers, and asked observers to select their preference. Observers were blinded to the source of contours. We calculated the percentage of cases in which observers preferred AI contours. Lastly, we evaluate whether the presence of AI contours improved the geometric accuracy of prostate contours provided by five resident observers for a 10-patient subset. RESULTS The median Dice coefficient between AI and reference contours was 0.92 (IQR: 0.90-0.94). Observers preferred AI contours for a median of 57.5% (IQR: 47.5, 65.0) of the test cases. For resident observers, the presence of AI contours was associated with a 0.107 (95% CI: 0.086, 0.128; p < 0.001) improvement in Dice coefficient for the 10-patient subset. CONCLUSION The AI algorithm provided high-quality prostate contours on TRUS with implanted needles. Further prospective study is needed to better understand how to incorporate AI prostate contours into the TRUS-based HDR brachytherapy workflow.
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Catheter reconstruction and dosimetric verification of MRI-only treatment planning (MRTP) for interstitial HDR brachytherapy using PETRA sequence. Phys Med Biol 2023; 68. [PMID: 36584396 DOI: 10.1088/1361-6560/acaf48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 12/30/2022] [Indexed: 12/31/2022]
Abstract
Objective. The feasibility of MRI-only treatment planning (MRTP) for interstitial high-dose rate (HDR) brachytherapy (BT) was investigated for patients diagnosed with gynecologic cancer.Approach. A clinical MRTP workflow utilizing a 'pointwise encoding time reduction with radial acquisition (PETRA)' sequence was proposed. This is a clinically available MRI sequence optimized to improve interstitial catheter-tissue contrast. Interstitial needles outside the obturator region were reconstructed using MR images only. For catheters penetrating through the obturator, a library-based reconstruction was proposed. In this work, dwell coordinates from the clinical CT-based reconstruction were used as the surrogate for the library-based approach. For MR-only plan, dwell times were activated and assigned as in the clinical plans. The catheter reconstruction was assessed by comparing dwell position coordinates. The dosimetric comparisons between a clinical plan and MR-only plan were assessed for physical and EQD2 dose and volume parameters forD90,D50andD98for clinical target volume (CTV) andD2cc,D0.1ccandD5ccfor OARs.Main results. Catheter reconstruction was possible using the optimized PETRA sequence on MR images. An overall reconstruction difference of 1.7 ± 0.5 mm, attributed to registration-based errors, was found compared to the CT-based reconstruction. The MRTP workflow has the potential to generate a treatment plan with an equivalent dosimetric quality compared to the conventional CT/MRI-based approach. For CTVD90, physical and EQD2 dose and volume parameter differences were 1.5 ± 1.9% and 0.7 ± 1.0 Gy, respectively. ForD2ccOARs, DVH (EQD2) differences were -0.4 ± 1.1% (-0.2 ± 0.5 Gy), 0.5 ± 2.8% (0.2 ± 1.3 Gy) and -0.5 ± 1.4% (-0.2 ± 0.5 Gy) for rectum, bladder, and sigmoid, respectively.Significance. With the proposed MRTP approach, CT imaging may no longer be needed in HDR BT for interstitial gynecologic treatment. A proof-of-concept study was conducted to demonstrated that MRTP using PETRA is feasible, with comparable dosimetric results to the conventional CT/MRI-based approach.
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PO11. Brachytherapy 2022. [DOI: 10.1016/j.brachy.2022.09.117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Saturday, June 18, 20227:40 AM - 5:00 PMPO22 Presentation Time: 7:40 AM. Brachytherapy 2022. [DOI: 10.1016/j.brachy.2022.09.128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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PP03 Presentation Time: 9:20 AM. Brachytherapy 2022. [DOI: 10.1016/j.brachy.2022.09.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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PO27 Presentation Time: 7:40 AM. Brachytherapy 2022. [DOI: 10.1016/j.brachy.2022.09.133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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Risk-adaptive paradigm for focal versus whole-gland salvage treatment for radio-recurrent prostate cancer. Front Oncol 2022; 12:998390. [PMID: 36249064 PMCID: PMC9554650 DOI: 10.3389/fonc.2022.998390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/13/2022] [Indexed: 11/20/2022] Open
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Topical imiquimod in combination with brachytherapy for unresectable cutaneous melanoma scalp metastases. JAAD Case Rep 2022; 31:62-65. [PMID: 36505038 PMCID: PMC9731864 DOI: 10.1016/j.jdcr.2022.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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First pointwise encoding time reduction with radial acquisition (PETRA) implementation for catheter detection in interstitial high-dose-rate (HDR) brachytherapy. Brachytherapy 2022; 21:501-510. [PMID: 35337748 DOI: 10.1016/j.brachy.2022.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 12/15/2021] [Accepted: 01/15/2022] [Indexed: 11/02/2022]
Abstract
PURPOSE A pointwise encoding time reduction with radial acquisition (PETRA) sequence was optimized to detect empty catheters in interstitial (HDR) brachytherapy with clinically acceptable spatial accuracy for the first time. Image quality and catheter detectability were assessed in phantoms, and the feasibility of PETRA's clinical implementation was assessed on a gynecological cancer patient. METHODS AND RESULTS Empty catheters embedded in a gelatin phantom displayed positive signal on PETRA and more accurate cross-sections than on clinically employed T2-weighted sequences, differing by 0.4 mm on average from their nominal 2 mm diameter. PETRA presented minimal susceptibility differences and a symmetric metal artifact, contrary to the clinical sequences. The PETRA-CT catheter tip position differences assessed by a treatment planning system (TPS) were < 1 mm. PETRA also detected an interstitial template with empty catheters penetrating a poultry phantom and fused very well with CT. Interstitial catheter positional difference between PETRA and CT images was < 1 mm on average, increasing with distance from isocenter. All interstitial catheters and the employed interstitial template were detected on PETRA images of an endometrial adenocarcinoma patient. Empty needles were traceable using a TPS, with higher spatial resolution and more favorable contrast than on T2-weighted images used for contouring. A treatment plan could be produced by combining information from PETRA for catheter detection and from T2-weighted images for tumor and organs delineation. CONCLUSIONS PETRA detected successfully and accurately interstitial catheters in phantoms. Its first clinical implementation shows a potential for MR-only treatment planning in interstitial HDR brachytherapy.
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Interfraction dose deviation and catheter position in cervical interstitial and intracavitary image guided HDR brachytherapy. Med Dosim 2021; 47:e1-e6. [PMID: 34702633 DOI: 10.1016/j.meddos.2021.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/31/2021] [Accepted: 09/11/2021] [Indexed: 10/20/2022]
Abstract
Interstitial and intracavitary gynecological HDR brachytherapy involve precise, localized delivery to targets with high dose gradients, sparing adjacent organs at risk (OAR). Due to the proximity of the rectum, bowel and bladder to the target, deviations in the applicator or catheter with respect to patient anatomy can significantly increase dose to OAR. The magnitude and direction of applicator and catheter migration at each fraction was assessed for template interstitial and tandem and ring (T&R) cohorts. The cohort included twelve gynecological patients with intact cervical lesions treated with external beam and brachytherapy. Pre-treatment CT images were registered to the simulation CT with respect to the target. Treatment catheter positions transformed into the planning CT coordinate system to evaluate localized catheter displacement and dose distributions calculated at each fraction. Dose was evaluated on the planning CT with planning contours and dwell locations at treatment position. Absolute deviation, depth and deflection angle for all patients were 4.6 ± 4.2 mm, -1.4 ± 4.0 mm, and 3.1 ± 2.3° respectively (n = 516 catheter positions for all treatment fractions and patients, mean ± SD). Absolute catheter deviation and deflection magnitude for interstitial treatments increased overall with each subsequent fraction with an overall increase of catheter retraction at each fraction (p < 0.005, n = 492 catheters, Kruskal-Wallis). A target EQD2 D90 reduction of 10 ± 10% and 7.7 ± 8.7% of the planned dose for interstitial and T&R cohorts respectively. There was an overall increase in bladder and rectal doses at each fraction. Catheter tracking in interstitial and intracavitary gynecological treatments with CT imaging revealed significant changes in catheter positioning with respect to the target volume. Overall deviations increased in magnitude with each subsequent fraction in the interstitial treatments. This caused patient dosimetry deviations, including target dose reduction and adjacent OAR doses changes.
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Feasibility of magnetic resonance-only high-dose-rate surface brachytherapy for clinical application. Med Phys 2021; 48:7313-7322. [PMID: 34519360 DOI: 10.1002/mp.15224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 08/19/2021] [Accepted: 08/30/2021] [Indexed: 11/12/2022] Open
Abstract
PURPOSE In this article, we investigate the feasibility of magnetic resonance (MR)-only imaging for high-dose-rate (HDR) surface brachytherapy (SABT). We examined whether a standard CT-based planning can be replaced with an MR-only planning. For this purpose, the MRI digitization and plan quality check processes were compared against the standard CT-based processes. A prospective clinical implementation of the MR-only planning was evaluated on a clinical data set. METHODS A pointwise encoding time reduction with radial acquisition (PETRA) sequence was optimized for visualization of Freiburg flap (FF) on MR images. MR and conventional CT images were acquired with a FF applicator (Elekta, Stockholm, Sweden) placed on the following phantoms: (1) flat styrofoam (FST), FF locked-in placed with supporting structure; (2) cast-made facemask, and (3) porcine leg (PL). Catheters were digitized and activated with 10 mm step size on Oncentra Brachy 4.5.3 Treatment Planning System. The CT-only and MR-only treatment plans were generated by optimizing the dose to the target defined as volume at 3 mm skin depth. To compare the plans, the MRI-to-CT alignment was performed via rigid registration. Positional displacements of dwell positions between CT and MR plans were compared on the FST phantom and the relative percent dose difference in 2210 different points from CT or MR-only plans was compared. For all three phantoms, the comparabilities between CT and MR-only plans were assessed by calculating dice similarity coefficient (DSC) for volumes enclosing 150%, 125%, 100%, 95%, 90%, 80%, and 65% isodose lines (V150 -V65 ). The MR images of FF placed on the forearm of a healthy subject were acquired with this optimized PETRA sequence and used for treatment planning. The relative percent dose was calculated on 140 representative points placed at 3 mm skin depth to evaluate the dose to the skin. RESULTS Using the optimized PETRA sequence, MRTP digitization accuracy was < 1 mm in each dimension and on three-dimensional (3D) displacement for the FST phantom. In each phantom and clinical data set, it was possible to generate MR-only treatment plans with the 3 mm skin depth prescription. In the FST phantom, the mean relative dose at the points was not significantly different (< 0.1% difference) for CT or MR-based plans. The assessment of similarities in dose profiles between CT and MR-only plans' provided DSC values greater than 0.96, 0.92, and 0.73 for all volumes enclosing up to 100%, 125%, and 150% isodose lines, respectively. CONCLUSION The feasibility of generating a HDR treatment plan with FF using MR-only has been evaluated in phantoms with varying geometry and for a clinical data set. The optimization of a standard MRI sequence-PETRA-implemented in this study showed that FF-based catheters can be digitized and a plan can be generated using only MRI. The resulting MR-only plans were comparable to the conventional CT-based plans, suggesting that MRI alone can generate clinically acceptable plans for FF in phantoms and on a clinical data set. Reliable MR-only treatment planning could improve treatment prescription through more accurate characterization of soft tissue targets.
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PP-0154 Knowledge-based Inverse Treatment Planning for Low-Dose-Rate Prostate Brachytherapy. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)06446-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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OC-0020 Freiburg Flap Surface Applicator Brachytherapy positional accuracy on MR-only PETRA images. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)06273-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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PO-0229 Towards informed and digitized HDR brachytherapy QA: Quantitative analysis of GYN applicators. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)06388-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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PHSOR09 Presentation Time: 10:40 AM. Brachytherapy 2021. [DOI: 10.1016/j.brachy.2021.06.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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OC-0022 MRI-guided Treatment Planning for Skin Brachytherapy with PETRA. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)06275-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Biopsy Needle System With a Steerable Concentric Tube and Online Monitoring of Electrical Resistivity and Insertion Forces. IEEE Trans Biomed Eng 2021; 68:1702-1713. [PMID: 33606624 DOI: 10.1109/tbme.2021.3060541] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Biopsies are the gold standard for clinical diagnosis. However, a discrepancy between the biopsy sample and target tissue because of misplacement of the biopsy spoon can lead to errors in the diagnosis and subsequent treatment. Thus, correctly determining whether the needle tip is in the tumor is crucial for accurate biopsy results. METHODS A biopsy needle system was designed with a steerable, flexible, and superelastic concentric tube; electrodes to monitor the electrical resistivity; and load cells to monitor the insertion force. The degrees of freedom were analyzed for two working modes: straight-line and deflection. RESULTS Experimental results showed that the system could perceive the tissue type in online based on the electrical resistivity. In addition, changes in the insertion force indicated transitions between the interfaces of adjacent tissue layers. CONCLUSION The two monitoring methods guarantee that the biopsy spoon is at the desired position inside the tumor during an operation. SIGNIFICANCE The proposed biopsy needle system can be integrated into an autonomous robotic biopsy system.
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Definitive radiotherapy for vaginal recurrence of early-stage endometrial cancer: survival outcomes and effect of mismatch repair status. Int J Gynecol Cancer 2021; 31:1007-1013. [PMID: 33858956 DOI: 10.1136/ijgc-2021-002536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/25/2021] [Accepted: 03/29/2021] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE To evaluate clinical outcomes, prognostic factors, and toxicity in patients with vaginal recurrence of early-stage endometrial cancer treated with definitive radiotherapy. METHODS Retrospective review identified 62 patients with stage I-II endometrial cancer and vaginal recurrence treated with external beam radiotherapy and image-guided brachytherapy with definitive intent from November 2004 to July 2017. All patients had prior hysterectomy without adjuvant radiotherapy and >3 months follow-up. Mismatch repair (MMR) status was determined by immunohistochemical staining of the four mismatch repair proteins (MLH1, MSH2, PMS2, and MSH6) when available in the pathology record. Rates of vaginal control, recurrence-free survival, and overall survival were calculated by Kaplan-Meier. Univariate and multivariate analyses were performed by Cox proportional hazards. RESULTS Most patients had endometrioid histology (55, 89%), grade 1 or 2 tumor (53, 85%), and vaginal-only recurrence (55, 89%). With a median follow-up of 39 months (range, 3-167), 3- and 5-year rates of vaginal control, recurrence-free survival, and overall survival were 86% and 82%, 69% and 55%, and 80% and 61%, respectively. On multivariate analysis, non-endometrioid histology (HR 12.5, P<0.01) was associated with relapse when adjusted for chemotherapy use. Patients with non-endometrioid histology also had a 4.5-fold higher risk of death when adjusted for age (P=0.02). Twenty patients had known MMR status, all with grade 1-2 endometrioid tumors and 10 (50%) with MMR deficiency. The 3-year recurrence-free survival was 100% for MMR-proficient tumors and 52% for MMR-deficient (P=0.03). Late grade 2 and 3 gastrointestinal, genitourinary and vaginal toxicity was reported in 27% and 3%, 15% and 2%, and 16% and 2% of patients, respectively. CONCLUSION Definitive radiotherapy with image-guided brachytherapy resulted in 5-year local control rates exceeding 80% and late severe toxicity rates were under 3%. Distant recurrence was common and highest for those with grade 3 or non-endometrioid tumors and MMR deficient grade 1-2 disease.
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Knowledge-based inverse treatment planning for low-dose-rate prostate brachytherapy. Med Phys 2021; 48:2108-2117. [PMID: 33586191 DOI: 10.1002/mp.14775] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/17/2021] [Accepted: 02/04/2021] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Permanent low-dose-rate brachytherapy is a widely used treatment modality for managing prostate cancer. In such interventions, treatment planning can be a challenging task and requires experience and skills of the planner. We developed a novel knowledge-based (KB) optimization method based on previous treatment plans. The purpose of this method was to generate clinically acceptable plans that do not require extensive manual adjustments in clinical scenarios. METHODS Objective functions used in current inverse planning methods are preferably based on spatial invariant dose objectives rather than spatial dose distributions. Therefore, they are prone to return suboptimal plans resulting in time consuming plan adjustments. To overcome this limitation, a KB approach is introduced. The KB model uses the dose distributions of previous clinical plans projected onto a standardized geometry. From those standardized distributions a template plan is generated. The treatment plans were optimized with an in-house developed planning system by solving a constraint inverse optimization problem that mimics the projected template dose plan constraint to DVH metrics. The method is benchmarked under an IRB-approved retrospective study by comparing optimization time, dosimetric performance, and clinical acceptability against current clinical practice. The quality of the KB model is evaluated with a Turing test. RESULTS The KB model consists of five high-quality treatment plans. Those plans were selected by one of our experts and showed all desired dosimetric features. After generating the model treatment plans were created with one run of the optimizer for the remaining 20 patients. The optimization time including needle optimization ranged from 6 to 29 s. Based on a Wilcoxon signed rank test the new plans are dosimetrically equivalent to current clinical practice. The Turing test showed that the proposed method generates plans that are equivalent to current clinical practice and that the dose prediction drives the optimization to achieve high-quality treatment plans. CONCLUSIONS This study demonstrated that the proposed KB model was able to capture user-specific features in isodose lines which can be used to generate acceptable treatment plans with a single run of the optimization engine in under a minute. This could potentially reduce the time in the operating room and the time a patient is under anesthesia.
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OC-1043: Automated Plan Verification Software for Ultrasound-Planned High Dose Rate Prostate Brachytherapy. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)01980-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Evaluating Errors and Inefficiencies in Brachytherapy: An Approach Toward Process Redesign and Patient Safety. Int J Radiat Oncol Biol Phys 2020. [DOI: 10.1016/j.ijrobp.2020.07.1437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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OC-1027: Comparing GU toxicity of LDR I-125 prostate brachytherapy by robotic and manual loading techniques. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)01966-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Surface brachytherapy: Joint report of the AAPM and the GEC‐ESTRO Task Group No. 253. Med Phys 2020; 47:e951-e987. [DOI: 10.1002/mp.14436] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 07/15/2020] [Accepted: 07/16/2020] [Indexed: 02/06/2023] Open
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Low-dose adjuvant vaginal cylinder brachytherapy for early-stage non-endometrioid endometrial cancer: recurrence risk and survival outcomes. Int J Gynecol Cancer 2020; 30:1908-1914. [PMID: 32655012 DOI: 10.1136/ijgc-2020-001623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/15/2020] [Accepted: 06/18/2020] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE The aim of this study was to evaluate recurrence patterns and survival outcomes for patients with early-stage non-endometrioid endometrial adenocarcinoma treated with adjuvant high-dose rate vaginal brachytherapy with a low-dose scheme. METHODS A retrospective review was performed of patients with International Federation of Gynecology and Obstetrics (FIGO) stage I-II non-endometrioid endometrial cancer who received adjuvant vaginal brachytherapy with a low-dose regimen of 24 Gy in six fractions from November 2005 to May 2017. All patients had >6 months of follow-up. Rates of recurrence-free survival, overall survival, vaginal, pelvic, and distant recurrence were calculated by the Kaplan-Meier method. Prognostic factors for recurrence and survival were evaluated by Cox proportional hazards modeling. RESULTS A total of 106 patients were analyzed. Median follow-up was 49 months (range 9-119). Histologic subtypes were serous (47%, n=50), clear cell (10%, n=11), mixed (27%, n=29), and carcinosarcoma (15%, n=16). Most patients (79%) had stage IA disease, 94% had surgical nodal assessment, and 13% had lymphovascular invasion. Adjuvant chemotherapy was delivered to 75%. The 5-year recurrence-free and overall survival rates were 74% and 83%, respectively. By histology, 5-year recurrence-free/overall survival rates were: serous 73%/78%, clear cell 68%/88%, mixed 88%/100%, and carcinosarcoma 56%/60% (p=0.046 and p<0.01). On multivariate analysis, lymphovascular invasion was significantly associated with recurrence (HR 3.3, p<0.01). The 5-year vaginal, pelvic, and distant recurrence rates were 7%, 8%, and 21%, respectively. Vaginal and pelvic recurrence rates were highest for patients with carcinosarcoma, lymphovascular invasion and/or FIGO stage IB/II disease. At 5 years, vaginal and pelvic recurrence rates for patients with lymphovascular invasion were 33% and 40%, respectively. Patients with stage IA disease or no lymphovascular invasion had 5-year vaginal recurrence rates of 4% and pelvic recurrence rates of 6% and 3%, respectively. CONCLUSIONS Adjuvant high-dose rate brachytherapy with a low-dose scheme is effective for most patients with early-stage non-endometrioid endometrial cancer, particularly stage IA disease and no lymphovascular invasion. Pelvic radiation therapy should be considered for those with carcinosarcoma, lymphovascular invasion and/or stage IB/II disease.
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Development and clinical implementation of semi-automated treatment planning including 3D printable applicator holders in complex skin brachytherapy. Med Phys 2020; 47:869-879. [PMID: 31855280 DOI: 10.1002/mp.13975] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 12/04/2019] [Accepted: 12/09/2019] [Indexed: 11/09/2022] Open
Abstract
PURPOSE High-dose-rate brachytherapy (HDR-BT) is a treatment option for malignant skin diseases compared to external beam radiation therapy, HDR-BT provides improved target coverage, better organ sparing, and has comparable treatment times. This is especially true for large clinical targets with complex topologies. To standardize and improve the quality and efficacy of the treatments, a novel streamlined treatment approach in complex skin HDR-BT was developed and implemented. This approach consists of auto generated treatment plans and a 3D printable applicator holder (3D-AH). MATERIALS AND METHODS The in-house developed planning system automatically segments computed tomography simulation images (a), optimizes a treatment plan (b), and generates a model of the 3D-AH (c). The 3D-AH is used as an immobilization device for the flexible Freiburg flap applicator used to deliver treatment. The developed, automated planning is compared against the standard clinical plan generation process for a flat 10 × 10 cm2 field, curved fields with radii of 4, 6, and 8 cm, and a representative clinical case. The quality of the 3D print is verified via an additional CT of the flap applicator latched into the holder, followed by an automated rigid registration with the original planning CT. Finally, the methodology is implemented and tested clinically under an IRB approval. RESULTS All automatically generated plans were reviewed and accepted for clinical use. For the clinical workflow, the coverage achieved at a prescription depth for the flat 4, 6, and 8 cm applicator was (100.0 ± 4.9)%, (100.0 ± 4.9)%, (96.0 ± 0.3)%, and (98.4 ± 0.3)%, respectively. For auto planning, the coverage was (99.9 ± 0.3)%, (100.0 ± 0.2)%, (100.0 ± 0.3)%, and (100.1 ± 0.2)%. For the clinical test case, the D90 for the clinical workflow and auto planning was found to be 93.5% and 100.29% of the prescribed dose, respectively. Processing of the patient's CT to generate trajectories and positions as well as the 3D model of the applicator took <5 min. CONCLUSION This workflow automates time intensive catheter digitizing and treatment planning. Compared to printing full applicators, the use of 3D-AH reduces the complexity of the 3D prints, the amount of the material to be used, the time of 3D printing, and amount of quality assurance required. The proposed methodology improves the overall treatment plan quality in complex HDR-BT and impact patient treatment outcomes potentially.
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Definitive and Postoperative Radiation Therapy for Basal and Squamous Cell Cancers of the Skin: Executive Summary of an American Society for Radiation Oncology Clinical Practice Guideline. Pract Radiat Oncol 2019; 10:8-20. [PMID: 31831330 DOI: 10.1016/j.prro.2019.10.014] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 10/01/2019] [Indexed: 01/21/2023]
Abstract
PURPOSE This guideline reviews the evidence for the use of definitive and postoperative radiation therapy (RT) in patients with basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC). METHODS The American Society for Radiation Oncology convened a task force to address 5 key questions focused on indications for RT in the definitive and postoperative setting for BCC and cSCC, as well as dose-fractionation schemes, target volumes, basic aspects of treatment planning, choice of radiation modality, and the role of systemic therapy in combination with radiation. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength. RESULTS The guideline recommends definitive RT as primary treatment for patients with BCC and cSCC who are not surgical candidates while conditionally recommending RT with an emphasis on shared decision-making in those situations in which adequate resection can lead to a less than satisfactory cosmetic or functional outcome. In the postoperative setting, a number of indications for RT after an adequate resection are provided while distinguishing the strength of the recommendations between BCC and cSCC. One key question is dedicated to defining indications for regional nodal irradiation. The task force suggests a range of appropriate dose-fractionation schemes for treatment of primary and nodal volumes in definitive and postoperative scenarios. The guideline also recommends against the use of carboplatin concurrently with adjuvant RT and conditionally recommends the use of systemic therapies for unresectable primaries where treatment may need escalation. CONCLUSIONS Defining the role of RT in the management of BCC and cSCC has been hindered by a lack of high-quality evidence. This document synthesizes available evidence to define practice guidelines for the most common clinical situations. We encourage practitioners to enroll patients in prospective trials and to approach care in a multidisciplinary fashion whenever possible.
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Low-Dose Adjuvant Cylinder Brachytherapy for Endometrioid Endometrial Cancer. Pract Radiat Oncol 2019; 10:95-103. [PMID: 31783169 DOI: 10.1016/j.prro.2019.11.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 11/04/2019] [Accepted: 11/07/2019] [Indexed: 12/22/2022]
Abstract
PURPOSE Our purpose was to evaluate outcomes and sites of failure for women with early stage endometrial adenocarcinoma treated with adjuvant high-dose-rate (HDR) vaginal brachytherapy (VB) with a low dose scheme. METHODS AND MATERIALS Retrospective review identified 318 patients with International Federation of Gynecology and Obstetrics (FIGO) stage I-II endometrioid endometrial cancer who received adjuvant HDR VB to a dose of 24 Gray (Gy) in 6 fractions from 2005 to 2017. Patients with <6 months follow-up were excluded. Dose was prescribed to cylinder surface and computerized tomography (CT) imaging was performed before each fraction to assess cylinder placement. Rates of vaginal relapse (VR), pelvic nodal relapse, distant metastasis, recurrence-free survival, and overall survival were calculated by Kaplan-Meier method. Univariate analysis was performed by log rank test or Cox proportional hazards. Pretreatment CT images were analyzed for patients with VR. RESULTS Median follow-up was 42 months for 243 patients. The 3-year rates of VR, pelvic nodal relapse, distant metastasis, recurrence-free survival, and overall survival were 1.9%, 1.5%, 4.3%, 94.1%, and 98.9%, respectively. The 3-year VR rates by Gynecologic Oncology (GOG)-99 risk groups were 0%, 1.4%, and 3.2% for low risk, low-intermediate risk, and high-intermediate risk (HIR) disease (P = .5). By Post-operative Radiation Therapy in Endometrial Carcinoma (PORTEC) risk stratification, 3-year VR rate was 1.3% for HIR disease. On review of pretreatment CT images of the 6 patients with VR, 3 patients had relapse at the introitus outside of the treated vaginal length, and 3 had in-field recurrence at the vaginal apex. Higher body mass index (BMI) was associated with VR, with a 14% increase in risk per BMI unit (kg/m2, P = .02). There were no reported grade 2 GI or any grade 3 toxicities. CONCLUSIONS Adjuvant HDR VB with a low-dose regimen results in excellent clinical outcomes for patients with early stage endometrioid endometrial cancer. Patients with higher BMI may be at increased risk of VR, and additional study is needed to optimize brachytherapy treatment parameters.
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Vaginal Brachytherapy for Stage I-II Non-endometrioid Endometrial Cancer Using a Low-dose Scheme. Int J Radiat Oncol Biol Phys 2018. [DOI: 10.1016/j.ijrobp.2018.07.1756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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CT-guided Adjuvant Vaginal Brachytherapy for Endometrial Cancer: Efficacy and Sites of Failure with a Low-Dose Regimen. Int J Radiat Oncol Biol Phys 2018. [DOI: 10.1016/j.ijrobp.2018.07.1751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Fully Automated Planning with Patient Specific 3D-Printed Applicator-Holders for High-Dose-Rate Surface Brachytherapy. Brachytherapy 2018. [DOI: 10.1016/j.brachy.2018.04.061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Dosimetric Impact of Source Position Variation Inside Different Catheter Sizes in HDR Brachytherapy. Brachytherapy 2018. [DOI: 10.1016/j.brachy.2018.04.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Decomposition of Source Dwell Positions and Dwell Times: A Novel Method for Accurate Source Tracking and Quality Assurance in HDR Brachytherapy Based on Film Dosimetry. Brachytherapy 2018. [DOI: 10.1016/j.brachy.2018.04.239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Monte Carlo Insight into Inter-Seed Attenuation (ISA) in Salvage Brachytherapy of Post Permanent Prostate Implant (PPI). Brachytherapy 2018. [DOI: 10.1016/j.brachy.2018.04.152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Brachytherapy monotherapy may be sufficient for a subset of patients with unfavorable intermediate risk prostate cancer. Urol Oncol 2017; 36:157.e15-157.e20. [PMID: 29276060 DOI: 10.1016/j.urolonc.2017.11.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/22/2017] [Accepted: 11/30/2017] [Indexed: 11/28/2022]
Abstract
PURPOSE/OBJECTIVE(S) Brachytherapy (BT) monotherapy is a well-established treatment modality for favorable intermediate risk (FIR) prostate cancer. However, patients with unfavorable intermediate risk (UIR) disease are often recommended trimodality therapy involving BT, androgen deprivation therapy (ADT), and external beam radiation therapy (EBRT). We sought to investigate the relative benefit of supplemental therapies (ADT and/or EBRT) for FIR and UIR prostate cancer in a large dataset. MATERIALS/METHODS We identified 3,723 patients with intermediate risk prostate cancer treated with BT between 1997 and 2013, including 1,989 and 1,734 patients with FIR and UIR disease, respectively. For the FIR cohort, Fine and Gray's competing risks regression model was used to evaluate whether there was a difference in prostate cancer specific mortality (PCSM) between BT vs. BT + supplemental therapy (ADT, EBRT, or both). For the UIR cohort, this regression model was used to evaluate whether supplemental ADT, EBRT, or both decreased PCSM beyond BT alone. Both regression models were adjusted for clinical and treatment-related factors. RESULTS The median follow-up periods were 7.7 years (interquartile range: 5.4-10.5) for the FIR cohort and 7.8 years (interquartile range: 5.3-10.6) for the UIR cohort. For the FIR cohort, there was no difference in PCSM between BT monotherapy vs. BT + supplemental therapy (adjusted hazard ratio [AHR] = 1.70; 95% CI: 0.46-6.29; P = 0.43). For the UIR cohort, supplemental EBRT (AHR = 2.66; 95% CI: 1.12-6.34; P = 0.03), ADT (AHR = 0.96; 95% CI: 0.38-2.43; P = 0.93), or both (AHR = 1.46; 95% CI: 0.42-5.01; P = 0.55) were not associated with improved PCSM compared with BT alone. CONCLUSION In our analysis, supplemental therapies did not offer an improvement in PCSM compared with BT alone for FIR or UIR prostate cancers. Further prospective clinical trials are required to determine whether BT monotherapy may be sufficient for a subset of patients with UIR disease.
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Lack of Benefit From the Addition of External Beam Radiation Therapy to Brachytherapy for Intermediate- and High-risk Prostate Cancer. Int J Radiat Oncol Biol Phys 2017; 99:904-911. [PMID: 29063853 DOI: 10.1016/j.ijrobp.2017.07.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 07/11/2017] [Accepted: 07/24/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE A recent randomized controlled trial demonstrated that the addition of external beam radiation therapy (EBRT) to brachytherapy did not improve progression-free survival in select patients with intermediate-risk prostate cancer. We evaluated whether the addition of EBRT to brachytherapy improves prostate cancer-specific mortality (PCSM) for intermediate- and high-risk disease using a large national database. METHODS AND MATERIALS We identified 5836 patients in the Surveillance, Epidemiology, and End Results-Medicare linked database with a diagnosis of National Comprehensive Cancer Network intermediate-risk (Gleason score 7, prostate-specific antigen 10-20 ng/mL, or stage cT2b-T2c) or high-risk (Gleason score 8-10 or prostate-specific antigen >20 ng/mL and stage ≤cT3a) prostate cancer who had undergone brachytherapy, with or without EBRT and androgen deprivation therapy (ADT). Patients were diagnosed from 2004 through 2009. Intermediate-risk patients with Gleason score ≤3+4 and 1 intermediate-risk factor were considered favorable and all others unfavorable. We used multivariable Fine-Gray competing risks regression to study PCSM while adjusting for sociodemographic and clinical factors and ADT use. RESULTS Overall, 50.3% of intermediate- and high-risk patients who received brachytherapy and EBRT did not have significantly improved PCSM compared with that of the patients who received brachytherapy alone (adjusted hazard ratio [AHR] 1.46, 95% confidence interval [CI] 0.69-3.11; P=.322; 5-year PCSM 2.4% vs 1.0%). This lack of benefit was seen among favorable intermediate-risk (AHR 2.66, 95% CI 0.93-7.62, P=.069; 5-year PCSM 1.3% vs 0.6%), unfavorable intermediate-risk (AHR 0.68, 95% CI 0.16-2.96, P=.612; 5-year PCSM 1.0% vs 1.2%), and high-risk (AHR 1.82, 95% CI 0.67-4.98, P=.242; 5-year PCSM 5.3% vs 2.1%) subgroups. CONCLUSIONS These results suggest that certain patients with intermediate- or high-risk prostate cancer treated with brachytherapy might not benefit from the addition of EBRT. A randomized controlled trial of brachytherapy plus ADT with or without EBRT for unfavorable intermediate- and favorable high-risk organ-confined prostate cancer should be undertaken.
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Supplemental Androgen Deprivation Therapy Is More Beneficial Than Supplemental External Beam Radiation Therapy for Men with Unfavorable Intermediate Risk Prostate Cancer Treated with Brachytherapy. Int J Radiat Oncol Biol Phys 2017. [DOI: 10.1016/j.ijrobp.2017.06.1193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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The value of systematic contouring of the bowel for treatment plan optimization in image-guided cervical cancer high-dose-rate brachytherapy. Brachytherapy 2017; 16:579-585. [PMID: 28256433 DOI: 10.1016/j.brachy.2017.01.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 01/17/2017] [Accepted: 01/18/2017] [Indexed: 11/24/2022]
Abstract
PURPOSE To investigate the dose-volume histogram metrics and optimization results of the contoured bowel in cervical cancer brachytherapy. METHODS AND MATERIALS Treatment plans of cervical cancer patients treated with image-guided high dose rate were retrospectively analyzed with institutional review board approval. In addition to the clinical target volume, rectum, bladder, and sigmoid, the bowel was contoured at the time of planning (Group 1) or at the time of this analysis (Group 2). RESULTS Thirty-two patients treated with 145 insertions were included. Before optimization, mean ± 1 standard deviation overall bowel minimum dose to the most irradiated 2 cm3 volume of an organ (D2cc) was 67.8 Gyα/β3 ± 13.7 Gyα/β3 (Group 1: 72.6 ± 13.2 Gyα/β3; Group 2: 57.3 ± 8.0 Gyα/β3). Before optimization, one patient in Group 1 presented a bowel D2cc metric exceeding 100 Gyα/β3. After optimization, bowel D2cc mean ± 1 standard deviation was 59.4 ± 6.7 Gyα/β3 (Group 1: 61.4 ± 6.0 Gyα/β3, p < 0.001; Group 2: 55.2 ± 6.5 Gyα/β3, p = 0.026). CONCLUSIONS Given the potentially high doses and the benefit of optimization in reducing dose to the organs at risk, we recommend consideration of systematic contouring of the bowel when bowel is present in the pelvis.
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Improving Dose Accuracy of HDR Brachytherapy Treatment of Skin Lesions Using Freiburg Flap Applicator Based on Reference Radiochromic Film Dose Measurements. Brachytherapy 2017. [DOI: 10.1016/j.brachy.2017.04.191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Outcomes with volume-based dose specification in CT-planned high-dose-rate brachytherapy for stage I-II cervical carcinoma: A 10-year institutional experience. Gynecol Oncol 2016; 143:545-551. [PMID: 27720445 DOI: 10.1016/j.ygyno.2016.09.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 09/13/2016] [Accepted: 09/16/2016] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To determine prognostic factors for progression-free survival (PFS) and overall survival (OS) for stage I-II cervical-cancer patients treated using computed-tomography (CT)-planned high-dose-rate (HDR) intracavitary brachytherapy (BT). METHODS A total of 150 patients were treated for Stage I-II cervical cancer using CT-planned BT between 4/2004 and 10/2014. Of these, 128 were eligible for inclusion. Kaplan-Meier local control (LC), pelvic control (PC), overall survival (OS), and PFS estimates were calculated. RESULTS After a median follow-up of 30months, the 2-year LC rate was 96%, PFS was 88%, and OS was 88%. Overall, 18 patients (14%) experienced any recurrence (AR), 8 had distant recurrence only and 10 had a combination of local, pelvic, regional, and distant recurrence. No patients had LR only. A prognostic factor for AR was tumor size >4cm (p=0.01). Patients with tumors >4cm were 3.3 times more likely to have AR than those with tumors ≤4cm (hazard ratio [HR]=3.3; 95% confidence interval [CI] 1.28-9.47). Point A was 85% of prescription for tumors < 4 cm and decreased approximately 3% over 5 fractions compared to 90% of prescription for tumors > 4 cm that decreased approximately 4% over 5 fractions. Two patients (2%) experienced grade≥2 late toxicity. There were no acute or late grade≥3 toxicities. CONCLUSION CT-planned BT resulted in excellent local control and survival. Large tumor size was associated with an increased risk of recurrence outside the radiation field and worse PFS and OS. A volume-optimized plan treated a smaller area than a point A standard plan for patients with Stage I-II cervical cancer that have received chemoradiation. Given the outstanding LC achieved with modern therapy including chemoradiation, HDR, and image-based BT, further efforts to combat spread outside the radiation field with novel therapies are warranted.
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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. Med Phys 2016. [DOI: 10.1118/1.4957816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-F-T-242: A Method for Collision Avoidance in External Beam Radiation Therapy. Med Phys 2016. [DOI: 10.1118/1.4956382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-G-201-04: Can the Dynamic Library of Flap Applicators Replace Treatment Planning in Surface Brachytherapy? Med Phys 2016. [DOI: 10.1118/1.4956877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Improved Dose Conformality in Non-Image Based Treatment Planning for Vaginal Cylinders Using Shallower Dose Optimization Points. Brachytherapy 2016. [DOI: 10.1016/j.brachy.2016.04.198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Outcomes of Uterine Papillary Serous and Uterine Clear Cell Carcinoma Treated with Vaginal-Cylinder Brachytherapy Alone. Brachytherapy 2016. [DOI: 10.1016/j.brachy.2016.04.196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Use of a control film piece in radiochromic film dosimetry. Phys Med 2016; 32:202-7. [DOI: 10.1016/j.ejmp.2015.12.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Revised: 11/25/2015] [Accepted: 12/11/2015] [Indexed: 10/22/2022] Open
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Dosimetric Evaluations of CT and MR-Based Brachytherapy Treatment Plans for Cervical Cancers Using Consensus Contouring Atlases. Int J Radiat Oncol Biol Phys 2015. [DOI: 10.1016/j.ijrobp.2015.07.1260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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SU-E-J-226: Efficient Use of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) for Cervical-Cancer Brachytherapy. Med Phys 2015. [DOI: 10.1118/1.4924312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-E-T-413: Examining Acquisition Rate for Using MatriXX Ion Chamber Array to Measure HDR Brachytherapy Treatments. Med Phys 2015. [DOI: 10.1118/1.4924774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-E-T-783: Using Matrixx to Determine Transit Dose Contribution Over Clinically Useful Limits of HDR Source Activity. Med Phys 2015. [DOI: 10.1118/1.4925147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-E-T-301: Dosimetric Comparison Between Adaptive and Rectilinear Template-Based Prostate Seed Implants. Med Phys 2015. [DOI: 10.1118/1.4924662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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