[Radiotherapy of skeletal metastases]

Patients with skeletal metastases represent a large cohort in clinical oncology, and the single most frequent indication for palliative radiotherapy. Patients with cancer of the breast, lung, prostate and those with myelomatosis, constitute approximately 80% of this group.

This paper summarizes data from relevant published clinical trials employing external irradiation for painful skeletal metastases. More recent randomised trials support the view that a single radiation dose of 8-10 Gy is equally efficient as ten treatments of 3 Gy delivered over two weeks. However, some still believe that fractioned regimes to a higher total dose provide better pain relief of a longer duration than a single fraction.

We review the current diagnosis and treatment of patients with skeletal metastases and discuss some aspect of tumour biology. The etiology of pain and the pathogenesis of tumour cells affecting bone tissue, resulting in osteolysis and/or osteosclerosis, are discussed. Associated leukocyte-derived osteoclast-activating cytokines that stimulate pain receptors locally, can in part explain why radiotherapy gives such rapid pain relief.

The aims of radiotherapy must be assessed in relation to the life expectancy of the patient. Based on actual publications and own experiences, we suggest treatment with 8 Gy x 1 for the majority of patients, and reserve 3 Gy x 10 for patients with longer life expectancy. Both regimes allow retreatment, if and when pain eventually reoccur in previously irradiated areas.