Abstract
Purpose: The purpose of this study was to prospectively analyze the safety and feasibility of spot scanning carbon ion radiotherapy (CIRT) for patients with localized prostate cancer.Methods: 118 localized prostate cancer patients treated with spot scanning CIRT at Shanghai Proton and Heavy Ion Center (SPHIC) were enrolled in this dose escalated study. The dose was gradually increased from 59.2GyE to 65.6GyE in 16 fractions. The primary endpoint was the acute and late toxicities. Secondary endpoints were biochemical relapse free survival (bRFS), distant metastasis free survival (DMFS), prostate cancer-specific survival (PCSS), and overall survival (OS).Results: The median follow-up time was 30.2 months (4.8-62.7 months). Acute grade 1 and 2 genitourinary (GU) toxicities were 15.3% and 18.6%, while acute grade 1 and 2 gastrointestinal (GI) toxicities were 2.5% and 0%, respectively. Late grade 1 and 2 GU toxicities were 4.2% and 1.7%, respectively. No late GI toxicity were observed. There were no cases of severe acute or late toxicity (≥grade 3). The significant association was not found between the factors and the acute GU toxicities except for CTV volume (p=0.031) on multivariate analysis. The 2-year bRFS, DMFS, PCSS, OS were 100%, 100%, 100% and 98.8%, respectively.Conclusion: The 2 years’ outcomes are encouraging, providing additional and useful information on the feasibility and safety of spot scanning CIRT for prostate cancer. Long term follow-up and prospective multi-institutional data are warranted to reinforce the role of CIRT in the management of localized prostate cancer.Trial registration: Clinicaltrial, NCT02739659. Registered 15 April 2016
A beam of hope for heavy ion radiotherapy: Promising clinical results and better designs are adding new momentum to the push for more proton and carbon ion radiotherapy centers
