Modeling tumor and treated lung volume influences in the irradiation of non-small-cell lung cancer patients

Purpose: The proposal of a hypothetical model in patients treated by irradi ation for non-small-cell lung cancer show the dependence of local tumor con trol and patient cure rates on the volume of tumor and irradiated lung tiss ue. Results: The local tumor control rates from conventional doses of irradiati on decreases and the metastases rate Increases with the tumor volume. Dose escalation will increase the potential cure rates (product of the local con trol and the freedom from metastases rates). Any potential gain will, howev er, be modified by the effect of irradiation on normal lung. Studies indica te that this is dependent on the volume of lung irradiated above a threshol d dose. Conclusion: A clinically significant and measurable increase in cure rates from dose escalation may be seen in smaller tumors. This is unlikely to occ ur in larger tumors, although dose escalation to a restricted volume combin ed with effective systemic chemotherapy is one of the options that may be e xplored. The relevance of modeling and future studies of tumor and normal t issue volume effects, will increase from the widespread usage of the dose-v olume histogram, (C) 2001 Elsevier Science Inc.