Federica Palorini1, Cesare Cozzarini2, Stefano Gianolini3, Andrea Botti4, Viviana Carillo1, Cinzia Iotti5, Tiziana Rancati6, Riccardo Valdagni7, Claudio Fiorino8. 1. Medical Physics, San Raffaele Scientific Institute, Milan, Italy. 2. Radiotherapy, San Raffaele Scientific Institute, Milan, Italy. 3. Medical Software Solutions GmbH, Switzerland. 4. Medical Physics, Arcispedale S.M. Nuova, Reggio Emilia, Italy. 5. Radiation Oncology Unit, Arcispedale S.M. Nuova, Reggio Emilia, Italy. 6. Prostate Cancer Program, Istituto Nazionale dei Tumori, Milan, Italy. 7. Prostate Cancer Program, Istituto Nazionale dei Tumori, Milan, Italy; Radiation Oncology 1, Istituto Nazionale dei Tumori, Milan, Italy. 8. Medical Physics, San Raffaele Scientific Institute, Milan, Italy. Electronic address: fiorino.claudio@hsr.it.
Abstract
PURPOSE: To develop a method for investigating local dose effects on the bladder after prostate cancer radiotherapy based on dose-surface maps (DSMs). BACKGROUND AND PURPOSE: DSMs of patients included in a prospective study (DUE01) were generated by virtually cutting bladder contours at the points intersecting the sagittal plane passing through its center-of-mass: maps were laterally normalized and aligned at the posterior inferior point. The average DSMs of patients with/without toxicity, the DSMs of differences and t statistic were used to select regions better discriminating patients with toxicity. A total of 72 patients with no/mild urinary symptoms before radiotherapy and who were treated with moderate hypo-fractionation (2.5-2.65Gy/fr, 70-74Gy) were considered, and the endpoint was an International Prostate Symptoms Score (IPSS)⩾15 at the end of therapy (IPSSend⩾15, n=25/72). RESULTS: The DSMs of patients with/without toxicity were significantly different (p<0.05). The percentage of bladder circumference receiving >50-70Gy at 5-7mm from the base was associated with an IPSSend⩾15 (odds ratios: 1.03-1.07). Different patterns were recognized for specific symptoms. With frequency/urgency, a quasi-threshold effect on the absolute posterior dose at 5-12mm from the base (2Gy equivalent doses=80-82Gy, α/β=3-5Gy) was observed. CONCLUSIONS: Local-dose effects for acute symptoms were detected in a group of patients treated within a moderately hypo-fractionated protocol. The results for frequency/urgency were consistent with a threshold effect on the trigone.
PURPOSE: To develop a method for investigating local dose effects on the bladder after prostate cancer radiotherapy based on dose-surface maps (DSMs). BACKGROUND AND PURPOSE: DSMs of patients included in a prospective study (DUE01) were generated by virtually cutting bladder contours at the points intersecting the sagittal plane passing through its center-of-mass: maps were laterally normalized and aligned at the posterior inferior point. The average DSMs of patients with/without toxicity, the DSMs of differences and t statistic were used to select regions better discriminating patients with toxicity. A total of 72 patients with no/mild urinary symptoms before radiotherapy and who were treated with moderate hypo-fractionation (2.5-2.65Gy/fr, 70-74Gy) were considered, and the endpoint was an International Prostate Symptoms Score (IPSS)⩾15 at the end of therapy (IPSSend⩾15, n=25/72). RESULTS: The DSMs of patients with/without toxicity were significantly different (p<0.05). The percentage of bladder circumference receiving >50-70Gy at 5-7mm from the base was associated with an IPSSend⩾15 (odds ratios: 1.03-1.07). Different patterns were recognized for specific symptoms. With frequency/urgency, a quasi-threshold effect on the absolute posterior dose at 5-12mm from the base (2Gy equivalent doses=80-82Gy, α/β=3-5Gy) was observed. CONCLUSIONS: Local-dose effects for acute symptoms were detected in a group of patients treated within a moderately hypo-fractionated protocol. The results for frequency/urgency were consistent with a threshold effect on the trigone.
Authors: Leila E A Shelley; Michael P F Sutcliffe; Simon J Thomas; David J Noble; Marina Romanchikova; Karl Harrison; Amy M Bates; Neil G Burnet; Raj Jena Journal: Phys Imaging Radiat Oncol Date: 2020-04
Authors: Oscar Casares-Magaz; Ludvig P Muren; Niclas Pettersson; Maria Thor; Austin Hopper; Rick Knopp; Joseph O Deasy; Michael Væth; John Einck; Vitali Moiseenko Journal: Phys Imaging Radiat Oncol Date: 2018-10-05
Authors: Wouter Schaake; Arjen van der Schaaf; Lisanne V van Dijk; Alfons C M van den Bergh; Johannes A Langendijk Journal: PLoS One Date: 2018-07-17 Impact factor: 3.240
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