The relation of CT-determined tumor parameters and local and regional outcome of tonsillar cancer after definitive radiation treatment.
OBJECTIVE
To investigate the value of CT-derived tumor parameters as predictor of local and regional outcome of tonsillar squamous cell carcinoma treated by definitive radiation therapy.


METHODS
The pretreatment CT studies of 112 patients with tonsillar squamous cell carcinoma were reviewed. After redigitizing the films, primary and nodal tumor volume was calculated with the summation-of-areas technique. The nodal CT aspect was graded using a 3-point scale (homogenous, inhomogeneous, and necrotic). Mean follow-up time was 33 months. Actuarial statistical analysis of local and regional outcome was done for each of the covariates; multivariate analysis was performed using Cox's proportional hazards model.


RESULTS
In the actuarial analysis, CT-determined primary tumor volume was significantly correlated with local recurrence rate (p < 0.05) when all patients were considered, but primary tumor volume did not predict local control within the T2, T3, and T4 category. CT-determined nodal volume was significantly related to regional outcome (p < 0.01), but nodal density was not. Total tumor volume was not significantly related to locoregional outcome (p = 0.1). In the multivariate analysis, the T and N categories were the independent predictors of local and regional outcomes, respectively.


CONCLUSIONS
Compared to other head-and-neck sites, primary and nodal tumor volume have only marginal predictive value regarding local and regional outcome after radiation therapy in tonsillar cancer.
Hermans
R
R
Department of Radiology, University Hospitals, Katholieke Universiteit, Herestraat 49, B-3000 Leuven, Belgium. Robert.Hermans@uz.kuleuven.ac.be
Op de beeck
K
K
Van den Bogaert
W
W
Rijnders
A
A
Staelens
L
L
Feron
M
M
Bellon
E
E
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000532:radiotherapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D014067:Tonsillar Neoplasms / Q000473:pathology* / Q000532:radiotherapy*; D016896:Treatment Outcome