Setting the Stage: Feasibility and Baseline Characteristics in the PARTIQoL Trial Comparing Proton Therapy Versus...

Area of Science:

• Radiation Oncology
• Clinical Trials
• Prostate Cancer Treatment

Background:

• Localized prostate cancer treatment options include photon-based intensity modulated radiation therapy (IMRT) and proton beam therapy (PBT).
• Assessing the comparative effectiveness and feasibility of large-scale trials for these modalities is crucial for optimizing patient care.

Purpose of the Study:

• To demonstrate the feasibility of conducting a large, multicenter, phase 3 randomized trial (PARTIQoL) comparing PBT and IMRT for localized prostate cancer.
• To report baseline characteristics of patients enrolled in the PARTIQoL trial and outline strategies for improving trial feasibility.

Main Methods:

• Patients with low- or intermediate-risk prostate cancer were randomized to PBT or IMRT.
• Stratification included institution, age, rectal spacer use, and fractionation schedule (conventional vs. moderate hypofractionation).
• Primary endpoint: change in bowel health (Expanded Prostate Index Composite score) at 24 months; secondary endpoints: urinary/erectile function, adverse events, and efficacy.

Main Results:

• 450 patients were accrued between July 2012 and November 2021, with 437 analyzed.
• Patient demographics and disease characteristics were balanced between the PBT (N=226) and IMRT (N=224) arms.
• Treatment modalities included conventional or hypofractionation, with 48% of PBT patients receiving pencil beam scanning and 48% using a rectal spacer.

Conclusions:

• The PARTIQoL trial successfully demonstrated the feasibility of a large, phase 3 randomized trial comparing PBT and IMRT for localized prostate cancer.
• Targeted recruitment, multicenter collaboration, payer engagement, and protocol updates were key to overcoming challenges.
• Further analysis of primary results and long-term follow-up for secondary endpoints are ongoing.