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

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. 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 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. 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 differences in measurement of TV by both methods decreases. CT TV results pre as well as post-treatment were more consistent than clinical method. 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