BACKGROUND AND PURPOSE: To define the influence of the dose and time on the response to treatment in postoperatively irradiated @entity135 @entity1 and to establish a good prediction of failure. METHODS AND MATERIALS: From January 1985 to December 1995, 214 @entity1 with histologically proven @entity213 were irradiated after radical surgery or single @entity5 resection according to surgical and histopathological findings. The total doses given ranged between 50 and 75 Gy to the primary bed @entity5 and between 42 and 56 Gy to the neck with fraction sizes of 1.7-2 Gy/day. The median length of the time interval between surgery and radiotherapy, time of irradiation and total treatment time were 81, 59 and 139 days, respectively. The end-point analyzed was the local-regional @entity5 control rate at the primary @entity5 bed and neck for 5 years from the beginning of radiotherapy. Univariate and multivariate analyses were used to determine predictors of failure from among the following studied variables: (i), clinical stage (T/N) of the @entity1 ; (ii), @entity5 grade; (iii), neck surgery; (iv), @entity5 margins; (v), histological @entity5 nodal extension; (vi), chemotherapy; (vii), normalized total dose; (viii), time interval between surgery and radiotherapy; (ix), time of irradiation; and (x), total treatment time. RESULTS: The actuarial 5-year @entity5 control rate for the entire group was 72%, and 92% of the @entity1 who achieved local control are currently alive without disease. Tumour control was inversely related to T stage (83% for T2 vs. 57% for T4) and the probability of local control within each stage was dependent on the N status (> or =71% for T3-T4/N0 vs. 31-44% for T3-T4/N1-N3). Histological N status and @entity5 margins, but not @entity5 grade, @entity5 control. When local control was analyzed as a function of the dose to the primary, a non-significant negative dose-response relationship was found. The total treatment time was a significant prognostic factor, and the time interval between surgery and irradiation proved to be an independent predictor of failure. CONCLUSIONS: Despite the absence of a statistically significant dose-response relationship, the present results suggest that postoperative irradiation treatment given to @entity1 with @entity213 should not be unduly prolonged, in order to minimize the amount of @entity5 cell proliferation. In these @entity1 , nodal involvement, positive margins of the resected specimens and time interval between surgery and irradiation were the most important prognostic factors.

Time-dose-response relationships in postoperatively irradiated @entity1 with XXXX .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity135 :: ('MESH:D006258', 'Disease') :: ['head and neck cancer'] @entity5 :: ('MESH:D009369', 'Disease') :: ['impacted significantly on tumour', 'tumour'] @entity213 :: ('MESH:C535575', 'Disease') :: ['head and neck squamous cell carcinomas']
@entity213 :: (MESH:C535575,Disease) :: ['head and neck squamous cell carcinomas']
