Comparing the Effectiveness of Combined External Beam Radiation and Hyperthermia Versus External Beam Radiation Alone in Treating Patients With Painful Bony Metastases: A Phase 3 Prospective, Randomized, Controlled Trial

Abstract

Purpose: To compare the response, duration of pain relief, and time to achieve complete pain relief after radiation therapy (RT) with or without hyperthermia (HT) in patients with painful bony metastases.

Methods and materials: Cancer patients with bony metastases and pain score ≥4 on the Brief Pain Inventory (BPI) were randomized to RT of 30 Gy in 10 fractions combined with HT (RT + HT) versus RT alone. Hyperthermia was performed by the Thermotron RF-8, with maintenance of the target temperature for 40 minutes per treatment within 2 hours after RT, twice weekly for 2 weeks. Patients were stratified by lesion number (solitary or multiple), BPI score (4-6 vs 7-10), and primary site. The primary endpoint was complete response (CR) (BPI = 0 with no increase of analgesics) within 3 months after treatment. This study was registered with ClinicalTrials.gov.

Results: The study was terminated early after an interim analysis of 57 patients, 3 years after the first enrollment (November 2013 to November 2016): 29 patients in the RT + HT group and 28 patients in the RT-alone group. The CR rate at 3 months after treatment was 37.9% in the RT + HT group versus 7.1% in the RT-alone group (P=.006). The accumulated CR rate within 3 months after treatment was 58.6% in the RT + HT group versus 32.1% in the RT-alone group (P=.045). Median time to pain progression was 55 days in patients with CR (n=9) in the RT-alone group, whereas the endpoint was not reached during the 24-week follow-up in the RT + HT group (P<.01).

Conclusions: The addition of HT to RT significantly increases the pain control rate and extends response duration compared with RT alone for painful bony metastases.