We compared radiotherapy outcomes between 241 elderly patients aged ≥75 years and 867 younger controls (age <75 years) with clinically localized prostate cancer. The elderly group showed an equivalent actuarial seven-year biochemical failure-free survival rate (7y-bNED) (94.9%) to the younger control group (96.4%, p = 0.593). The incidence of late genitourinary (GU) and gastrointestinal (GI) toxicities grade ≥2 was also similar between the elderly and younger cohorts, while no grade ≥4 adverse events occurred. We also examined the role of brachytherapy (BT) in the elderly group, in comparison with image-guided intensity-modulated radiotherapy (IG-IMRT). BT showed superior 7y-bNED (94.1%) than IG-IMRT (84.6%, p = 0.0183) in elderly patients, which was 100% (100% for BT and 100% for IG-IMRT, p > 0.999) for the low-risk group, 94.6% (92.8% and 100%, p = 0.203) for the intermediate-risk group, and 80.5% (91.2% and 73.6%, p = 0.0195) for the high-risk group. BT showed higher GU toxicity and equivalent GI toxicity to IG-IMRT. In conclusion, elderly patients showed bNED and toxicity that were equivalent to those observed in younger controls, and BT is a plausible option also for healthy elderly with potential to improve bNED, with higher but acceptable GU toxicity.
Keywords: IG-IMRT; brachytherapy; elderly; high dose rate; low dose rate; prostate cancer.