Stereological Evaluation of Laryngeal Cancers Using Computed Tomography Via the Cavalieri Method

Abstract

Tumor volume is accepted to be a significant prognostic factor for cancers arising in the head and neck regions. There were few studies on laryngeal tumor volume calculations. The purposes of this study were (1) to describe and adapt the relevant methods of computed tomography and stereology to estimate laryngeal tumor volume measured by the Cavalieri method; (2) to examine the possible correlation between tumor size and the number of involved neck lymph nodes in patients with laryngeal malignancies; and (3) to investigate if there is left-right asymmetry for this correlation and the number of involved lymph nodes in bilateral laryngeal malignancies. Fifty-two patients with bilateral laryngeal cancer only from a total of 137 patients with laryngeal cancer who underwent neck dissection during the study period were included in the study. In all cases, neck dissection was part of the treatment of laryngeal cancer. The Cavalieri estimator was used to estimate the tumor volumes on computed tomographic images. The tumor volume increased with the number of involved lymph nodes in the bilateral laryngeal malignancies in both the right and left neck regions. In addition, the volume of the primary lesion and the number of lymph node metastases in the cancer cells in the right neck region were well correlated in patients with laryngeal cancer but not the number of lymph node metastases in the left neck region. Correct, unbiased, reliable volume measurements for staging and therapeutic decision making of laryngeal cancers via the Cavalieri method may be possible.