Effect comparison between a new hypofractionated radiotherapy regimen and conventional moderately hypofractionated regimen for localized prostate cancer
摘要
The incidence of Prostate cancer (PC) has risen steadily in China, and hypofractionated radiotherapy offers a biologically advantageous and time-efficient treatment strategy. However, long-term data in Chinese populations are limited. This study evaluated the 10-year outcomes of hypofractionated radiotherapy regimen (45 Gy in 9 fractions) for localized PC. A propensity score–matched comparison was conducted to contextualize its effectiveness and toxicity relative to a moderately hypofractionated regimen.
MethodsFrom October 2011 to April 2017, thirty patients with localized PC who received hypofractionated radiotherapy (45 Gy in 9 fractions) were enrolled in this prospective trial. Ninety-five patients treated with a moderately hypofractionated regimen at the same center between February 2009 and October 2019 were selected. The propensity score matching (PSM) was applied to balance the potential confounding bias. Survival outcomes were analyzed using the Kaplan–Meier method. Genitourinary (GU) and gastrointestinal (GI) toxicities (grade ≥ 2) were assessed using the National Cancer Institute’s Common Terminology Criteria for Adverse Events (version 3.0) and Radiation Therapy Oncology Group late morbidity criteria. The primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS), biochemical recurrence-free survival (bRFS), PC-specific survival (PCSS), and GU and GI toxicities.
ResultsAfter a median follow-up of 10.3 years, patients treated with the 45 Gy in 9 fractions regimen achieved favorable long-term outcomes, with the 10-year PFS, bRFS, and OS rates of 78.1%, 93.3%, and 84.3%, respectively, with no prostate cancer–related deaths. PSM analysis yielded 60 comparable patients: (36 in the 67.5 Gy/25 fractions group and 24 in the 45 Gy//9 fractions group). No significant differences were observed between the 45 Gy/9 fractions and 67.5 Gy/25 fractions groups in 10-year OS (72.1% vs. 73.5%, P = 0.583), PFS (68.8% vs. 75%,P = 0.205), or freedom from failure(95.8% vs.94.0%, P = 0.757) Regarding toxicity, the 45 Gy /9 fractions was associated with significantly lower GI toxicity compared with the moderately hypofractionated regimen (P = 0.018), whereas GU toxicity did not differ significantly between groups (P = 0.757).
ConclusionsAfter long-term follow-up, the hypofractionated radiotherapy regimen of 45 Gy /9 fractions showed encouraging survival outcomes and acceptable toxicity in patients with localized PC. In the propensity score-matched analysis, no statistically significant differences in oncologic outcomes were observed between the 45 Gy/9 fractions regimen and the moderately hypofractionated regimen, while lower gastrointestinal toxicity was observed in the 45 Gy/9 fractions group. however, this finding should be interpreted cautiously in light of the limited sample size, non-randomized design, and technical differences between the cohorts.
Trial registrationChiCTR-ONC-12001895. Registered retrospectively on 28 January 2012.