ROC analysis of benefit and limitation in radiotherapy for cancer of the oral cavity.

The ROC analysis of optimalization of radiation treatment of cancer of the oral cavity was carried out. Material of 210 patients with squamous cell carcinoma (SCC) of the oral cavity was included into the study. Based on dose-response curves for tumor and late mucosal reactions, iso-utility curves and optimal k values were estimated. Optimal k values decreased from 0.792 to 0.584 with extension of overall treatment time from 35 to 49 days. It may suggest that the planning of additional dose to compensate tumor clonogens repopulation during prolonged treatment time does not improve therapeutic gain in radiotherapy for cancer of the oral cavity. The ROC is a useful model to estimate optimal radiation treatment for a given tumor because it is independent of any arbitrary consensus or theoretical assumption.