Are positron emission tomography-computed tomography (PET-CT) scans useful in preoperative assessment of patients with peritoneal disease before cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC)?

Abstract

Introduction: CRS and HIPEC confer survival benefit in selected patients with peritoneal metatases (PM). Accurate preoperative assessment of disease burden and exclusion of distant metastases are crucial in selecting the appropriate patient. We evaluate the utility of PET-CT scans in comparison with CT and MRI scans in patients considered for CRS and HIPEC. Methods: Data were retrospectively collected from patients who had been discussed for CRS and HIPEC between January 2011 and December 2015, at our institutional multidisciplinary tumour board. Patients who underwent PET-CT scan were included. Results of PET-CT were compared against traditional imaging. Patient and tumour factors were analysed to identify those who were most likely to benefit from PET imaging. Results: Four hundred and seven patients were considered for CRS and HIPEC. PET-CT was performed for 128(31.4%) patients: being the only imaging modality in 37 and used as an adjunct in 91. In the latter group, it was not beneficial in 58 patients as it provided no additional information (n = 33) or showed lesions of minimal FDG uptake (n = 25). In 33 patients, PET-CT provided definitive answers for indeterminate lesions seen on CT and MRI, confirmed the diagnosis of peritoneal disease in 10 patients (30.3%), identified extra-peritoneal disease and/or nodal metastases in 15 (45.5%) and excluded peritoneal disease in 8 (24.2%). The usefulness of PET-CT was predicted by tumour histology (p =.009), with non-mucinous tumours benefitting the most. Conclusion: Our results suggest that PET-CT can be used as an adjunct to CT and/or MRI scans, when lesions on the CT/MRI scans are indeterminate, and that it is most useful in patients with non-mucinous tumours.