Purpose: To compare the results of CT and positron emission tomography (PET) and F-18 fluorodeoxyglucose (FDG) in the detection of the primary tumor and lymph node metastases in carcinoma of the vagina.
Methods and materials: This was a prospective registry study of 23 consecutive patients with carcinoma of the vagina, in which we respectively compared the results of CT and whole-body FDG-PET. The tumor was clinical Stage II in 16 patients, Stage III in 6, and Stage IVa in 1 patient. The primary tumor ranged in size from 2 to 10 cm (mean 4.9), and 4 patients had palpable groin lymph nodes. All patients were treated with external beam radiotherapy and brachytherapy, 14 received concurrent chemotherapy, and 2 underwent primary tumor excision before the imaging evaluation. The median follow-up was 21 months in those patients alive without disease. Survival was estimated by the Kaplan-Meier method.
Results: Of the 21 patients with an intact primary tumor, CT visualized it in 9 (43%). CT also demonstrated abnormally enlarged groin lymph nodes in 3 patients and both groin and pelvic lymph nodes in 1 patient (4 of 23, 17%). FDG-PET identified abnormal uptake in all 21 intact primary tumors (100%). Abnormal uptake was found in the groin lymph nodes in 4 patients, pelvic lymph nodes in 2, and both groin and pelvic lymph nodes in 2 patients (8 of 23, 35%). The 3-year progression-free and overall survival estimate was 73% and 68%, respectively.
Conclusion: The results of this study have demonstrated that FDG-PET detects the primary tumor and abnormal lymph nodes more often than does CT.