Background: Conservative surgery (CS) brachytherapy (BT) techniques for local therapy in bladder-prostate rhabdomyosarcoma (BP-RMS) seek to retain organ function. We report bladder function after high-dose rate (HDR) BT combined with targeted CS for any vesical component of BP-RMS. Procedure:Prospective cohort of all BP-RMS patients between 2014 and 2019 receiving HDR-BT (iridium-192, 27.5 Gy in five fractions) with/without percutaneous endoscopic polypectomy (PEP) or partial cystectomy (PC). Functional assessment included frequency-volume chart, voided volumes, post-void residual, flow studies, continence status and ultrasound scanning; abnormalities triggered video urodynamics.Results: Thirteen patients (10 male), aged 9 months to 4 years (median 23 months), presented with localised fusion-negative embryonal BP-RMS measuring 23-140 mm (median 43 mm) in cranio-caudal extent. After induction chemotherapy, local treatment consisted of PC+BT in three, PEP+BT in four and BT alone in six. At a median 3.5 years (range 21 months to 7 years) follow-up, all were alive without relapse. At a median age of 6 years (4-9 years), the median bladder capacity was 86% (47%-144%) of that expected for age, including 75% (74%-114%) after PC. Radiation dose to the bladder was associated with urinary urgency, but not bladder capacity or nocturnal enuresis. Complications occurred in two: one urethral stricture and one vesical decompensation in a patient with pre-existing high-grade vesico-ureteric reflux (VUR). The remaining patients were dry by day; five with anticholinergic medication for urinary urgency. Three patients are enuretic.Conclusions: Day-time dryness at a median 3.5 years after CS-HDR-BT was achieved in 92%, with 85% voiding urethrally, and 62% attaining day-and-night continence aged 4-9 years. We report reduced open surgery with minimally invasive percutaneous surgery, with HDR-BT or BT alone being suitable for many.Abbreviations: BP-RMS, bladder-prostate rhabdomyosarcoma; BT, brachytherapy; CS, conservative surgery; CT, computed tomography; CTV, clinical target volume; D 0.1 cm3 , minimum dose received by 0.1 cm 3 of tissue that receives the highest dose; D 2 cm3 , minimum dose received by the 2 cm 3 of tissue that receives the highest dose; D90, minimum dose to 90% of the volume; EBCA, expected bladder capacity for age; EBR, external beam radiotherapy; EFS, event-free survival; EpSSG, European paediatric Soft tissue sarcoma Study Group; EQD 2 , dosimetric equivalent if the radiation is delivered in 2-Gy fractions and is based on the radiosensitivity of the tissue, quantified by the tissue alpha beta ratio; Fr, French; HDR, high-dose rate; LDR, low-dose rate; MRI, magnetic resonance imaging; OAR, organ at risk; PC, partial cystectomy; PDR, pulsed-dose rate; PEP, percutaneous endoscopic polypectomy; PVR, post-void residual; VUR, vesico-ureteric reflux.
Background: Conservative-surgery (CS) brachytherapy (BT) techniques for local therapy in bladder-prostate rhabdomyosarcoma (BP-RMS) seeks to retain organ function. We report bladder function after high-dose-rate (HDR) BT combined with targeted CS for any vesical component of BP-RMS. Procedure: Prospective cohort of all BP-RMS patients between 2014-19 receiving HDR-BT (Iridium-192, 27.5Gy in 5 fractions) with/without percutaneous endoscopic-polypectomy (PEP) or partial cystectomy (PC). Functional assessment included frequency-volume-chart, voided volumes, post-void residual, flow studies, continence status and ultrasound scanning; abnormalities triggered video-urodynamics. Results: Thirteen patients (10 male), aged 9 months to 4 years (median 23 months), presented with localised fusion-negative embryonal BP-RMS measuring 23-140mm (median 43mm) in cranio-caudal extent. After induction chemotherapy, local treatment consisted of PC+BT in three, PEP+BT in four and BT alone in six. At a median 3½ years (range 1¾-7 years) follow up, all were alive without relapse. At a median age of 6 years (4-9 years), the median bladder capacity was 86% (47%-144%) of that expected for age, including 75% (74-114%) after PC. There was no relation to radiation dose to the bladder. Complications occurred in two: one urethral stricture and one vesical decompensation in a patient with pre-existing high-grade VUR. The remaining patients are dry by day; five with anticholinergic medication for urinary urgency. Three patients are enuretic. Conclusions: Day-time dryness at a median 3½ years after CS-HDR-BT was achieved in 92%, with 85% voiding urethrally, and 62% attaining day-and-night continence aged 4-9 years. We report reduced open surgery, with minimally-invasive percutaneous surgery with HDR-BT or brachytherapy alone being suitable for many.
The purpose of this study was to compare low-dose-rate prostate brachytherapy treatment plans created using three retrospectively applied planning techniques with plans delivered to patients. METHODS AND MATERIALS: Treatment plans were created retrospectively on transrectal ultrasound (TRUS) scans for 26 patients. The technique dubbed 4D Brachytherapy was applied, using TRUS and MRI to obtain prostatic measurements required for the associated webBXT online nomogram. Using a patient's MRI scan to create a treatment plan involving loose seeds was also explored. Plans delivered to patients were made using an intraoperative loose seed TRUS-based planning technique. Prostate V 100 (%), prostate V 150 (%), prostate D 90 (Gy), rectum D 0.1cc (Gy), rectum D 2cc (Gy), urethra D 10 (%), urethra D 30 (%), and prostate volumes were measured for each patient. Statistical analysis was used to assess and compare plans. RESULTS: Prostate volumes measured by TRUS and MRI were significantly different. Prostate volumes calculated by the webBXT online nomogram using TRUS-and MRI-based measurements were not significantly different. Compared with delivered plans, TRUS-based 4D Brachytherapy plans showed significantly lower rectum D 0.1cc (Gy) values, MRI-based 4D Brachytherapy plans showed significantly higher prostate V 100 (%) values and significantly lower rectum D 0.1cc (Gy), urethra D 10 (%), and urethra D 30 (%) values, and loose seed MRI-based plans showed significantly lower prostate V 100 (%), prostate D 90 (Gy), rectum D 0.1cc (Gy), rectum D 2cc (Gy), urethra D 10 (%), and urethra D 30 (%) values. CONCLUSIONS: TRUS-based 4D Brachytherapy plans showed similar dosimetry to delivered plans; rectal dosimetry was superior. MRI can be integrated into the 4D Brachytherapy workflow. The webBXT online nomogram overestimates the required number of seeds.
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