Value of PET-CT in avoiding multimodality therapy in operable cervical cancer

Abstract

Background: Posttreatment morbidity of multimodality therapy is substantially higher than either radical surgery or chemoradiation alone. Preoperative prediction of positive nodes limits optimal selection of the primary treatment modality. Computed tomography (CT) and magnetic resonance imaging have been tried for nodal assessment with modest results. Positron emission tomography (PET) combined with CT seems to be promising in this regard. This clinicopathologic study assesses the value of PET-CT in predicting nodal metastasis and avoiding multimodality therapy.

Materials and methods: Eighty patients with clinically operable cervical cancer underwent PET-CT during the preoperative evaluation followed by radical hysterectomy. Adjuvant chemoradiation was administered when indicated by histopathologic findings. The histopathologic finding of the pelvic nodes was correlated with the PET-CT findings for nodal metastasis. The chi2 test was used as the test of significance in the statistical analysis.

Observations: Of 62 patients found PET-CT negative for nodal disease, 52 were true negative, whereas 10 were false negative on histopathologic examination. On the other hand, 14 of 18 patients found PET-CT positive for nodal disease were true positives. Specificity, sensitivity, positive predictive value, and negative predictive value of PET-CT in nodal assessment were found to be 92.8, 58.33, 77.7, and 83.8, respectively. Twenty-four patients (30%) with pelvic nodes positive for disease on histopathologic examination were administered adjuvant chemoradiation. Had we operated only on those patients who were PET-CT negative for nodal disease, 10 of 62 patients would have required adjuvant chemoradiation for positive nodes. Eighteen patients found PET-CT positive for nodal disease would be treated with primary chemoradiation. Inclusion of PET-CT in the decision-making process for primary surgery versus primary chemoradiation would allow 87.5% patients to receive a single modality of treatment (65%, only surgery; 22.5%, only chemoradiation) and the proportion of patients requiring multimodality treatment would reduce significantly from 30% to 12.5% (P < 0.01).

Conclusion: Positron emission tomography combined with CT in the evaluation of operable cervical cancer can help in the optimal selection of patients for surgery such that multimodality treatment with its attendant increase in morbidity is avoided.