Moderately hypofractionated radiotherapy for localized prostate cancer: updated long-term outcome and toxicity analysis.

Evaluation of long-term outcome and toxicity of moderately hypofractionated radiotherapy using intensity-modulated radiotherapy (IMRT) with simultaneous integrated boost treatment planning and cone beam CT-based image guidance for localized prostate cancer.

Between 2005 and 2015, 346 consecutive patients with localized prostate cancer received primary radiotherapy using cone beam CT-based image-guided intensity-modulated radiotherapy (IG-IMRT) and volumetric modulated arc therapy (IG-VMAT) with a simultaneous integrated boost (SIB). Total doses of 73.9 Gy (n = 44) and 76.2 Gy (n = 302) to the high-dose PTV were delivered in 32 and 33 fractions, respectively. The low-dose PTV received a dose (D95) of 60.06 Gy in single doses of 1.82 Gy. The pelvic lymph nodes were treated in 91 high-risk patients to 45.5 Gy (D95).

Median follow-up was 61.8 months. The 5‑year biochemical relapse-free survival (bRFS) was 85.4% for all patients and 93.3, 87.4, and 79.4% for low-, intermediate-, and high-risk disease, respectively. The 5‑year prostate cancer-specific survival (PSS) was 94.8% for all patients and 98.7, 98.9, 89.3% for low-, intermediate-, and high-risk disease, respectively. The 5‑year and 10-year overall survival rates were 83.8 and 66.3% and the 5‑year and 10-year freedom from distant metastasis rates were 92.2 and 88.0%, respectively. Cumulative 5‑year late GU toxicity and late GI toxicity grade ≥2 was observed in 26.3 and 12.1% of the patients, respectively. Cumulative 5‑year late grade 3 GU/GI toxicity occurred in 4.0/1.2%.

Moderately hypofractionated radiotherapy using SIB treatment planning and cone beam CT image guidance resulted in high biochemical control and survival with low rates of late toxicity.

Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al]. 2020 Aug 24 [Epub ahead of print]

Jörg Tamihardja, Max Schortmann, Ingulf Lawrenz, Stefan Weick, Klaus Bratengeier, Michael Flentje, Matthias Guckenberger, Bülent Polat

Department of Radiation Oncology, University Hospital Wuerzburg, University of Wuerzburg, Wuerzburg, Germany. ., Department of Radiation Oncology, University Hospital Wuerzburg, University of Wuerzburg, Wuerzburg, Germany., Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.