Long-term results of dose-intensified fractionated stereotactic body radiotherapy (SBRT) for painful spinal metastases
Mené sur 57 patients présentant des métastases vertébrales douloureuses (durée de suivi médiane : 60 mois), cet essai multicentrique de phase 2 évalue l'efficacité, du point de vue du soulagement de la douleur après 3 mois, d'un traitement par radiothérapie stéréotaxique
Purpose: To report long-term outcome of fractionated stereotactic body radiotherapy (SBRT) for painful spinal metastases. Material and Methods: This prospective single arm multi-center phase 2 clinical trial enrolled 57 patients with 63 painful, unirradiated spinal metastases between March 2012 and July 2015. Patients were treated 48.5 Gy in 10 SBRT fractions (long life expectancy [Mizumoto score ≤4]) or 35 Gy in 5 SBRT fractions (intermediate life expectancy [Mizumoto score 5-9]). Pain response was defined as pain improvement of minimum 2 points on a visual analogue scale (VAS) and net pain relief was defined as the sum of time with pain response (complete and partial) divided by overall follow-up time. Results: All 57 patients received treatment per-protocol, 32 and 25 patients were treated with 10- and 5-fraction SBRT, respectively. The median follow-up of living patients was 60 months, range 33-74. Of evaluable patients, 82% had complete or partial pain response (responders) at 3 months follow-up (primary endpoint) and pain response remained stable over 5 years. Net pain relief was 74% (95% CI, 65-80%). One-, 3- and 5-year overall survival rates were 59.6% (95% CI, 47-72%), 33.3% (95% CI, 21-46%) and 21% (95% CI, 10-32%), respectively. Freedom from local spinal-metastasis progression was 82% at the last imaging follow-up. Late Grade 3 toxicity was limited to pain in 2 patients (non-responders). There was no case of myelopathy. SBRT resulted in long-term improvements of all Euro-QoL-5D-5L dimensions except Anxiety/Depression. Conclusions: Fractionated SBRT achieved durable pain response and improved quality-of-life at minimum late toxicity.
International Journal of Radiation Oncology, Biology, Physics 2021