The clinical application of a dual head gamma camera with coincidence detection in 20 women with suspected ovarian cancer.

Abstract

To assess the effectiveness of a dual head coincidence gamma camera in identifying ovarian cancer as a less expensive alternative to the traditional 2-[18F] fluoro-2-deoxy-D-glucose (18FDG) system using positron emission tomography. Prospective study. Twenty consecutive women suspected of having ovarian carcinoma. Inclusion was based on abnormal serum CA125 (reference range is 0-35 units/L), ultrasound, computerised tomography or clinical findings. Women underwent assessment before staging laparotomy. Two nuclear medicine physicians, who were blinded to the pre-operative assessment, reported on 18FDG- dual head coincidence gamma camera imaging. The histology and operative staging were compared with the 18FDG- dual head coincidence gamma camera findings. Twelve women had pelvic malignancies (nine primary and three recurrences), seven women had benign pathology and one patient had a borderline malignancy. We were able to image accurately all malignant pelvic masses with dual head coincidence gamma camera, as well as accurately demonstrate disease spread. Two of the benign pelvic masses localised 18FDG. The positive predictive value for detecting malignancy was 86%. Dual head coincidence gamma camera offers accurate and affordable imaging in suspected ovarian masses, with improved specificity over CA125, ultrasound and computerised tomography. These results are similar to those obtained on more expensive dedicated PET systems. We report on a series of patients believed to have primary or recurrent carcinoma and recognise the need to include patients more likely to have benign lesions to assess false positive results. However, we believe that dual head coincidence gamma camera is useful in the pre-operative assessment of women with suspected ovarian cancer.