Background: The Tumor Node Metastasis (TNM) classification system describes head and neck tumors using anatomic or unidimensional criteria and may therefore fail to define the actual three-dimensional tumor bulk. To investigate this we measured variability of tumor volumes (Vvol) in T3-staged head and neck tumors.
Methods: Patient material consisted of pretreatment computerized tomography (CT) scans of 71 patients, seen between 1990 and 1995, with T3 head and neck carcinoma involving different subsites. Computerized tomographic scans of 42 patients displayed distinct tumor boundaries and were free of motion and/or dental artifacts. Using these scans, tumor volumes were measured using the summation-of-areas technique, and Vvol was determined.
Results: Following are the tumor-volume measurements: T3 larynx carcinoma (n = 12) Vvol, 1.7-17.0 mL (median 3.7 mL); T3 oropharynx carcinoma (n = 13) Vvol, 10.0-41.2 mL (median 18.3 mL); T3 hypopharynx carcinoma (n = 10) Vvol, 8.9-67.8 mL (me-dian 17.4 mL); T3 nasopharynx carcinoma (n = 3) Vvol, 3.7-30.1 mL; T3 maxillary sinus carcinoma (n = 4) Vvol, 56.0-103.1 mL.
Conclusions: T3-Staged tumors of the head and neck show considerable variability of tumor volumes. Incorporation of tumor volume data may further refine the TNM staging system.