Different imaging methods in the assessment of radiation-induced lung injury following hemithorax irradiation for pleural mesothelioma

Abstract

We have characterized the radiation-induced lung injury on serial chest X-rays, CTs and ultralow field MRs and evaluated the clinical value and cost/benefit ratio of the different imaging methods in 30 patients receiving high-dose hemithorax irradiation for pleural mesothelioma. Lung injury was severe in all patients, but non-specific and essentially as described in text-books. CT provided no clinically relevant, cost effective diagnostic advantage over conventional X-rays in the detection of early or late radiationinduced lung injury, but it was necessary for the evaluation of the disease status of mesothelioma. The possible advantage of MR over CT could not be evaluated and needs further studies. Optimal time-points for imaging CTs or MRs to detect early radiation-induced lung injury following high dose hemithorax irradiation were during the latter part of treatment or very shortly after the end of irradiation. Late injury or irreversible fibrosis developed rapidly after 6 months and was clearly documented by chest X-rays. We recommend serial chest X-rays at 1–2, 6 and 12 months following radiotherapy as a cost-effective method for the detection of radiation-induced lung injury with additional CTs to document the stage of mesothelioma, when needed.