<abstract xmlns="http://www.w3.org/1999/xhtml"><sec id="j_raon-2020-0075_s_006_w2aab3b7c78b1b6b1aab1c17b1Aa"><h3>Background</h3><p>Cure- and toxicity rates after intensity-modulated radiotherapy (IMRT) of prostate cancer are dose-and volume dependent. We prospectively studied the potential for organ at risk (OAR) sparing and compensation of tumor movement with the coverage probability (CovP) concept.</p></sec><sec id="j_raon-2020-0075_s_007_w2aab3b7c78b1b6b1aab1c17b2Aa"><h3>Patients and methods</h3><p>Twenty-eight prostate cancer patients (median age 70) with localized disease (cT1c–2c, N0, M0) and intermediate risk features (prostate-specific antigen [PSA] &lt; 20, Gleason score ≤ 7b) were treated in a prospective study with the CovP concept. Planning-CTs were performed on three subsequent days to capture form changes and movement of prostate and OARs. The clinical target volume (CTV) prostate and the OARs (bladder and rectum) were contoured in each CT. The union of CTV1–3 was encompassed by an isotropic margin of 7 mm to define the internal target volume (ITV). Dose prescription/escalation depended on coverage of all CTVs within the ITV. IMRT was given in 39 fractions to 78 Gy using the Monte-Carlo algorithm. Short-term androgen deprivation was recommended and given in 78.6% of patients.</p></sec><sec id="j_raon-2020-0075_s_008_w2aab3b7c78b1b6b1aab1c17b3Aa"><h3>Results</h3><p>Long-term toxicity was evaluated in 26/28 patients after a median follow-up of 7.1 years. At last follow-up, late bladder toxicity (Radiation Therapy Oncology Group, RTOG) G1 was observed in 14.3% of patients and late rectal toxicities (RTOG) of G1 (7.1%) and of G2 (3.6%) were observed. No higher graded toxicity occurred. After 7.1 years, biochemical control (biochemically no evidence of disease, bNED) was 95.5%, prostate cancer-specific survival and the distant metastasis-free survival after 7.1 years were 100% each.</p></sec><sec id="j_raon-2020-0075_s_009_w2aab3b7c78b1b6b1aab1c17b4Aa"><h3>Conclusions</h3><p>CovP-based IMRT was feasible in a clinical study. Dose escalation with the CovP concept was associated by a low rate of toxicity and a high efficacy regarding local and distant control.</p></sec></abstract>

BackgroundCure- and toxicity rates after intensity-modulated radiotherapy (IMRT) of prostate cancer are dose-and volume dependent. We prospectively studied the potential for organ at risk (OAR) sparing and compensation of tumor movement with the coverage probability (CovP) concept.Patients and methodsTwenty-eight prostate cancer patients (median age 70) with localized disease (cT1c–2c, N0, M0) and intermediate risk features (prostate-specific antigen [PSA] < 20, Gleason score ≤ 7b) were treated in a prospective study with the CovP concept. Planning-CTs were performed on three subsequent days to capture form changes and movement of prostate and OARs. The clinical target volume (CTV) prostate and the OARs (bladder and rectum) were contoured in each CT. The union of CTV1–3 was encompassed by an isotropic margin of 7 mm to define the internal target volume (ITV). Dose prescription/escalation depended on coverage of all CTVs within the ITV. IMRT was given in 39 fractions to 78 Gy using the Monte-Carlo algorithm. Short-term androgen deprivation was recommended and given in 78.6% of patients.ResultsLong-term toxicity was evaluated in 26/28 patients after a median follow-up of 7.1 years. At last follow-up, late bladder toxicity (Radiation Therapy Oncology Group, RTOG) G1 was observed in 14.3% of patients and late rectal toxicities (RTOG) of G1 (7.1%) and of G2 (3.6%) were observed. No higher graded toxicity occurred. After 7.1 years, biochemical control (biochemically no evidence of disease, bNED) was 95.5%, prostate cancer-specific survival and the distant metastasis-free survival after 7.1 years were 100% each.ConclusionsCovP-based IMRT was feasible in a clinical study. Dose escalation with the CovP concept was associated by a low rate of toxicity and a high efficacy regarding local and distant control.

Prospective evaluation of probabilistic dose-escalated IMRT in prostate cancer

Radiology and Oncology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Prospective evaluation of probabilistic dose-escalated IMRT in prostate cancer"}

BackgroundCure- and toxicity rates after intensity-modulated radiotherapy (IMRT) of prostate cancer are dose-and volume dependent. We prospectively studied the...

Prospective evaluation of probabilistic dose-escalated IMRT in prostate cancer

Article Category: Research Article

Published Online: Dec 22, 2020

Page range: 88 - 96

Received: Aug 31, 2020

Accepted: Nov 02, 2020

DOI: https://doi.org/10.2478/raon-2020-0075

© 2021 Daniel Wegener, Bernhard Berger, Zhoulika Outtagarts, Daniel Zips, Frank Paulsen, Martin Bleif, Daniela Thorwarth, Markus Alber, Oliver Dohm, Arndt-Christian Müller, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.