COMPLICATIONS FOLLOWING DEFINITIVE IRRADIATION FOR CANCERS OF THE ORAL CAVITY AND THE OROPHARYNX (IN A SERIES OF 1134 PATIENTS)

Purpose: To study the rate and severity of complications in a series o f 1134 patients treated by definitive irradiation for tumors of the or al cavity (772 cases) or the oropharynx (361 cases). Methods and Mater ials: Patients were staged as 29.5% T1, 42% T2, 26% T3, 2.5% T4-Tx, an d 74.5% N0 tumors. We treated 364 patients with brachytherapy only (Ir -192) for the primary lesion. External irradiation and brachytherapy w ere combined for 770 patients. Results: The results included local con trol and survival. Out of 1134 patients, 330 had 376 complications. Gr ade 1 complications occurred in 20% of the patients, Grade 2 in 9%; Gr ade 3 in 4%; and Grade 4 in 0.2%. Of the Grade 1 complications, 78% we re soft tissue and only 24% were bone complications. For the more seve re grades (2, 3, and 4), there were 56 soft tissue complications and 9 0 bone complications out of 1340 patients. The statistical analysis in cluded tumor-related factors and treatment-related factors. For the fi rst two factors, only tumor location was significant. The treatment-re lated factors significant for complications were studied in univariate and multivariate study. This multivariate study confirmed that for so ft tissue complications dose rate and volume treated were important (p < 0.001). It also confirmed that for bone complications, total dose > 80 Gy, dose rate >0.7 Gy/h, and the absence of leaded protection of th e mandible were all important factors. Conclusion: This statistical st udy should allow future reduction of severe complications (Grades 2, 3 , 4), if treatment factors inducing them can be taken into account. Th is is not always possible for very large tumors. (C) 1997 Elsevier Sci ence Inc.