Timing and dosage of postoperative radiotherapy for squamous cell carcinoma of the upper aerodigestive tract.

Seventy patients who received postoperative irradiation (PI) after curative surgery for stage III or IV squamous cell carcinoma of the upper aerodigestive tract were studied retrospectively to compare the rate of local and regional recurrence (LRR) and the effect of total dose on LRR rate in patients irradiated timely (n = 40) with those who were not (n = 30). Overall, the LRR rate was higher when PI was delayed than when timely (37% vs 20%). No advantage resulted from increasing total dose when PI was delayed; the LRR rate in the primary site and upper neck was 18% with less than 60 Gy and was 26% with 60 Gy or more; the LRR rate in the lower neck was 13% with 50 Gy or less and was 14% with more than 50 Gy. These data seem to corroborate the findings of other investigators regarding the importance of initiating timely PI, but not the observation that a pronounced delay is not detrimental provided higher tumoricidal doses are used.