Evaluation of Volume of Nasopharyngeal Cancers by the Cavalieri Principle

Document Type : Research Articles


1 Department of Otorhinolaryngology, Head and Neck Surgery, Medical Faculty, Ataturk University, Turkey.

2 Department of Radiation Oncology, Ataturk University, Turkey.


Prediction of tumor volume using the Cavalieri method may be helpful in management of therapy and evaluation of
treatment results. The aim of this study was to adapt the Cavalieri stereological method to magnetic resonance imaging
for determining volume of nasopharyngeal cancers and assess changes after treatment using the Cavalieri method.
Serial MRI images in the sagittal plane were obtained from a total of 33 patients with nasopharyngeal carcinomas
(11 with stage T2, 11 with stage T3, and 11 with stage T4 lesions). The images were analyzed retrospectively before
and two months following the cessation of radiochemotherapy for comparison. Average tumor volumes before and after
treatment in patients with stage T2 were 21. 5±10.5 cm3 and 2.82±3.43 cm3, respectively (p=0.000). The respective
figures were 35.1±19.0 cm3 and 6.27±7.82 cm3 (p=0.000) for stage T3 cases, and 62.8±27.8 cm3 and 11. 6±11.9 cm3
(p=0.000) for stage T4. Post-treatment tumor volumes were statistically reduced when compared to pre-treatment
volumes in all stages.


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