Palliative radiotherapy in plasma cell myeloma.

Pain symptoms caused by bone lesions of multiple myeloma can be relieved by a local irradiation treatment. To estimate the influence of systemic treatment on the palliative effect of local radiotherapy the records of 70 myeloma patients treated with chemotherapy combined with or followed by local irradiation were reviewed. The local response rate, defined as complete pain relief at the irradiated site, was 80% in patients receiving irradiation during chemotherapy (melphalan and prednisone) and this palliative effect endured 31.8 +/- 3.6 months. If irradiation was started in the period without systemic treatment the local response rate was 39.6% and lasted 24.8 +/- 17.9 months. In sites treated with more than one radiotherapy course 94% response rate after the first treatment, 56% after the second treatment and no response after the third course was achieved. The duration of local pain control was positively related to the applied radiation dose. It is concluded that irradiation during concomitant chemotherapy is superior to radiotherapy performed in a period without systemic treatment. Local long-term palliation can only be achieved by a sufficient high radiation dose.