This article originally appeared in Cancer Therapy Advisor.
Daily image-guided radiotherapy (IGRT) may reduce the rate of late rectal toxicity vs weekly therapy, according to research being presented at the 2018 Genitourinary Cancers Symposium in San Francisco, California. Daily IGRT was, however, also associated with a greater risk of secondary cancers and worse overall survival (OS).
It is unestablished whether daily or weekly IGRT is optimal for patients with N0 localized prostate cancer. For this 1:1 randomized phase 3 trial (ClinicalTrials.gov Identifier: NCT00433706), researchers assigned 470 patients to receive IGRT on a daily or weekly basis. Total doses ranged between 70 and 80 Gy; patients assigned to the weekly group received IGRT on days 1, 2, 3, and weekly thereafter.
The median follow-up was 4.1 years. No significant difference in recurrence-free survival was observed. Patients in the daily group had a better rate of late rectal toxicity (hazard ratio [HR], 0.71; P =.027), a longer biochemical progression-free interval (HR, 0.45; P =.007), and a longer clinical progression-free interval (HR, 0.50; P =.057).
The secondary cancer-free interval was, however, longer in the weekly group (HR, 2.21; P =.026); OS was also improved in the weekly group (HR, 2.12; P =.042).
de Crevoisier R, Bayar MA, Pommier P, et al. Daily versus weekly prostate cancer image-guided radiotherapy: A phase 3, multicenter, randomized trial. Oral presentation at: 2018 Genitourinary Cancers Symposium; February 8-10, 2018; San Francisco, CA.