Letter: The potentiating effect of prior local irradiation of the lungs on the development of pulmonary metastases.

Abstract

Radiotherapists who use wide-field regional techniques, or who electively irradiate clinically uninvolved sites may well be disturbed by experimental reports of increased “metastases” in irradiated organs. Several papers have been published in the past two years on the effect of local thoracic irradiation in promoting the efficiency of lung colony formation after intravenous injection of tumour cells in mice (Brown, 1973; Withers and Milas, 1973) and rats (van den Brenk et al., 1973; van den Brenk and Kelly, 1974). I should like to present here some limited data bearing on this topic and to make some personal observations on its implications for clinical radiotherapy.