Quantitative tumor volume VS TNM staging: the impact on prognosis in head and neck cancer.

Objectives: To evaluate the prognostic value of tumor volume (TV) by clinical method (CM) and Computerized Tomography (CT) scan in head and neck (H and N) cancer.

Materials And Methods: Total 25 patients' (pts) pretreatment tumor volume (PT TV) was assessed clinically by cuboid volume method. Afterwards contrast enhanced computerized tomography (CECT) images of the pts were transferred to workstation by DICOM software. The computerized tomography tumor volume (CT TV) was obtained on Radworks 6.0, using mouse control cursor. After assessment, the patients were given 3 cycles of neoadjuvant chemotherapy followed by radiotherapy by conventional method on Co-60 Theratron 780 C. After 1 month of treatment, TV was again measured.

Statistical Method: Statistical analysis was done on MSTAT statistical analysis software. Two-tailed student t test, chi square test and test for two proportions for significance had been used.

Results: Large variations in tumor volume were found both in intra as well as inter T-stages. As the tumor size increases with T stages, the difference in measurement of TV by both methods decreases. CT TV results pre as well as post-treatment were more consistent than clinical method.

Conclusion: The use of TV as a prognostic factor by CT scan seems to be more useful parameter than the CM. TV should be included in the TNM (tumor, node, and metastasis) classification after setting the strict guidelines for tumor delineation, to solve the discrepancy of treatment outcome in the same clinical stage.