Pain after palliative radiotherapy for spine metastases

The purpose of the study was to evaluate the response to palliative radiotherapy in patients with painful spinal metastatic disease (SMD).

Three hundred and fifty-five patients admitted to the Norwegian Radium Hospital for radiotherapy for painful SMD were included in a prospective study and were followed up 2 months later. The Brief Pain Inventory was used to assess pain. Analgesic consumption was recalculated into the daily oral morphine-equivalent dose. The radiotherapy-related response rates were calculated using the criteria of the International Bone Metastases Consensus Group (IBMCG), taking into account the use of concomitant analgesics. The response to radiotherapy was assessed as complete or partial and non-response as stable pain, pain progression or 'other'.

Brief Pain Inventory forms were obtained at follow-up from 229 of the 355 patients. Two months after radiotherapy, the median self-reported worst pain decreased significantly, but the median oral morphine-equivalent dose increased from 40 to 60 mg (P<0.001). Forty-three per cent of the patients reported pain relief, but a radiotherapy-related response was found in 37% of the patients. Overall correspondence between the patients' self-reported changes in pain experience and the IBMCG-based response categories was obtained in 63% of the patients.

The radiotherapy-related response rates in our study were lower than those reported previously in patients with bone metastases in general, which possibly indicates the presence of more complex pathophysiological mechanisms of pain in SMD.