Postoperative Radiotherapy Following Spinal Surgery Safe, Effective in Multiple Myeloma

The current standard of spinal surgery followed by postoperative radiotherapy for osteolytic lesions of multiple myeloma (MM) is safe and associated with a low toxicity profile, according to research published in Strahlentherapie und Onkologie.

“[In patients with osteolytic bone lesions of MM], a radiation dose of 30Gy delivered in 10-15 fractions is one of the most common RT regimens in this situation and is able to achieve significant reduction of pain in most patients,” the authors explained in their report. “However, data regarding both oncological and symptomatic outcomes such as pain response remain sparse and inconclusive.”

Researchers conducted a single-center, retrospective study of the outcomes of patients who underwent spinal surgery and postoperative RT due to MM. The primary endpoint was overall survival (OS), and secondary endpoints were progression-free survival (PFS), pain response, local control, and skeletal-related events. They also analyzed post-therapeutic adverse events and the Bilsky score and its role as a prognostic factor.

The study included 54 patients (median age, 67 years; range, 42-82 years) with multiple myeloma who underwent prior spinal surgery and postoperative RT between 2009 and 2020. The median follow-up duration was 63 months (95% CI, 49-94 months)

After surgery, the 3‑ and 5‑year OS was 74.9% (95% CI, 63.5-88.4%) and 58% (95% CI, 44.5-75.6%), respectively. Median survival was not reached. Median PFS was 26.5 months (95% CI, 20.9-48.4 months).

The proportion of patients with good-to-adequate performance status (Karnofsky performance score ≥70) significantly increased after surgery (50% vs 79.2%; P <.01). A majority of patients (92%) reported reduced pain after radiotherapy, with 66% reporting complete pain response. Pain response was not significantly associated with Bilsky score. 

Multivariate Cox regression revealed a Bilsky score of 2 or 3 is an independent negative prognostic factor for OS (HR, 3.89; 95 CI, 1.4-10.7; P <.01). Grade 1/2 adverse events (AEs) occurred in 24% of patients, and no grade 3/4 AEs occurred. Skeletal-related events occurred in 2 patients (4%). 

“To our knowledge, this is the first study to demonstrate both the safety and efficacy of RT in MM patients in an exclusively postsurgical setting of spinal lesions,” the authors wrote in their report. “The low rate of [skeletal-related events] and the absence of in-field recurrences demonstrate the efficacy of RT in MM patients. The Bilsky score is an easy-to-calculate prognostic tool and should be considered before dose prescription, given its prognostic value in MM patients receiving postoperative RT after spinal surgery.”

This article originally appeared on Hematology Advisor