Spinal Fracture After EBRT for Myeloma: Prediction and Prevention

By: Celeste L. Dixon
Posted: Friday, December 1, 2023

Almost one-third of patients with multiple myeloma who underwent conventional external-beam radiation therapy to the spine developed new or progressed vertebral compression fractures within 3 years, according to retrospective multicenter cohort study results published in The Spine Journal. Hester Zijlstra, MD, of Massachusetts General Hospital, Harvard Medical School, Boston, and colleagues also noted the Spinal Instability Neoplastic Score (SINS) was independently associated with the development of such fractures.

The outcome “highlight[s] the need for improved strategies to prevent fractures after radiation,” stated the team. Although radiation may treat severe pain, spinal cord compression, and malignancy-related bone disease in patients with multiple myeloma, it also “may be associated with increased risk of vertebral compression fractures, [potentially] impair[ing] survival and quality of life.”

The study included 127 patients (median age, 64 years; 66.1% male) with 427 eligible vertebrae radiated between 2010 and 2021. At the start of radiation therapy, 57 patients (44.9%) had at least one vertebral compression fracture. After radiation therapy, 39 of the 127 (30.7%) reported new fractures or progressed existing fractures (11.2% of all radiated vertebrae).

Use of the SINS in multiple myeloma has been debated, but the total SINS and categorical SINS showed independent associations (P < .001 for both) with higher rates of new or progressed vertebral compression fractures. For this reason, the authors suggested, the SINS could be applied in multiple myeloma for fracture prediction and possibly prevention. They also mentioned that prospective investigations attempt to validate the applicability of the SINS across diverse populations of patients (ie, those at different multiple myeloma disease stages or with varied treatment histories) to further assess the score’s predictive value.

To corroborate the study’s overall findings, future trials should include “a matched patient cohort who did not undergo radiotherapy to find out if there is actually a benefit from radiotherapy,” said the team. They also noted that the use of bisphosphonates was independently associated with a lower rate of new or progressed vertebral compression fractures (P = .027).

Disclosure: The study authors reported no conflicts of interest.

The Spine Journal

---