Peroperative radioimmunodetection of ovarian carcinoma using a hand-held gamma detection probe

Abstract

Summary Radioimmunoscintigraphy (RIS) can be used in the preoperative localisation of ovarian carcinoma to demonstrate uptake of radiolabelled monoclonal antibodies into neoplastic tissue. The tissue uptake of radiotracer was evaluated at laparotomy in 16 patients with suspected ovarian cancer who had preoperative RIS using technetium-99m-labelled monoclonal antibodies SM3 and H17E2. A gamma detection probe ('DP) was used to measure uptake in possible tumour deposits at operation and also the uptake in tissues resected for histology. The percentage uptake of the initial injected dose of radiotracer was also measured in resected tissues. Activity was found to be significantly higher in malignant than in non-neoplastic tissue by all three methods of evaluation. The yDP used peroperatively yielded a 82% sensitivity with a 72% specificity for an uptake ratio of 1.5:1. When tissue was examined immediately after resection, for a 100% specificity the sensitivity was 64%. In vitro measurements of monoclonal antibody uptake by tissue similarly gave a 65% sensitivity with a 100% specificity. Peroperative and immediate post-operative measurements of tissue radioactivity can be performed quickly and conveniently, and in some cases may be of benefit in the localisation of tumour at laparotomy and in providing extra information when tissue is examined by frozen section.Ovarian cancer has the worst prognosis of all gynaecological malignancies in the UK. It presents late and is often difficult to differentiate from benign lesions until surgery and histological examination have been performed. The surgical management of ovarian carcinoma is more complex than that of benign tumours and may be dictated by the results of histological frozen sections performed at the time of laparotomy. This is especially important in young women with unilateral ovarian tumours. In addition, a major factor determining the prognosis is whether or not there has been complete resection of the tumour. Therefore, accurate determination of the amount and extent of the tumour is essential. CT scans, pelvic ultrasound and surgical exploration, even when used together, are less than 100% accurate . However, radioimmunoscintigraphy using monoclonal antibodies against polymorphic epithelial mucin and other epitopes may yield more complete preoperative information (Granowska et al., 1984(Granowska et al., , 1990(Granowska et al., , 1993Davies et al., 1985;Epenetos et al., 1985;Jackson et al., 1985; Critchley et al., 1986;Shepherd et al., 1987;Jobling et al., 1990). We decided to assess the value of peroperative radioimmunodetection (PROD) using a specially designed gamma detection probe (yDP). We have also studied the value of measuring monoclonal antibody uptake in excised tissue as an aid to interpreting a frozen section. Patients and methodsSixteen patients having conventional routine radioimmunoscintigraphy prior to surgery for proven or suspected ovarian carcinoma were studied ( and other sites of possible involvement: Radioactivity that might come from ...

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