Hirofumi Ishikawa

OC-086 Survival Benefit of FDG-Pet Oriented Surgery for Recurrent Colorectal Cancer

Introduction Pivotal treatment for localised recurrent colorectal cancer is surgical resection. Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) has been accepted as an effective tool to identify disease localizations for patients with known or suspected recurrent colorectal cancer. This study is to analyse the survival benefit of FDG-PET on the diagnosis and indication of surgical intervention for Methods Consecutive 61 patients, with known or suspected recurrence of colorectal cancer based on elevation of tumour markers or abnormal findings on the follow-up CT image, underwent FDG-PET for 85 times between December 2003 and September 2009. Patients were aged between 39 and 94 years (median 66); 35 were male, 22 were Duke’s A or B stage, and 31 had a history of colon cancer. The average period between operation and first FDG-PET was 24 months (range 4–114). Of 61 cases 50 had elevated serum CEA or CA19–9 (82.0%). For each case the diagnosis of FDG-PET image was compared with that of CT image and the final diagnosis. Results Recurrence developed 2 times in average (range 1–6). Of 61patients five were identified recurrence by FDG-PET solely and indicated operation for 7 times. One of four shows disease-free survival for 70 months after common iliac replacement operation. FDG-PET showed one false – positive and three false – negative findings. Totally, the sensitivity of FDG-PET was 93.3% and its accuracy was 91.8%, whereas those of CT were 85.0% and 83.6%, respectively. Of 61patients 19 had diffused disease spread by FDG-PET findings and were judged as contraindication of operation and the other 42 with localised disease spread received operation for 90 times (liver 28, lung 14, local 37, local with distant meta 5, etc.). Cumulative 1-year and 3-year survival ratios of operation cases after first recurrence were 95% and 80%, whereas, those of contraindication cases were 60% and 25%, respectively. At present, the median survival period after recurrence of operation cases was longer than that of contraindication cases ( 37months v.s. 13months ). Our results suggested that one FDG-PET oriented operation roughly corresponded to one year survival benefit with restart. Conclusion Conclusion: FDG-PET could identify malignant lesions at earlier stage, and was an effective modality to evaluate not only disease spread but distant metastasis for recurrence of colorectal cancer. In this study, we first concretely demonstrated that FDG-PET oriented surgical indication had survival benefit for recurrent colorectal cancer. Disclosure of Interest None Declared

FDG-PET oriented surgery for recurrent colorectal cancer

Introduction Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) has been accepted as an effective tool of diagnosis and staging for patients with known or suspected recurrent colorectal cancer. Methods This study is to analyze the clinical significance of FDG-PET on the diagnosis and indication of surgical intervention for recurrent colorectal cancer. Consecutive 48 patients, with known or suspected recurrence of colorectal cancer based on elevation of tumour markers or abnormal findings on the follow-up CT image, underwent FDG-PET for 70 times between December 2003 and August 2009. Patients were aged between 35 and 89 years (median 48); 27 were male, 16 were Dukes A or B stage, and 26 had a history of colon cancer. The average of recurrence was two times (range 1–6). The average period between operation and first FDG-PET was 25 months (range 1–89). Of 48 cases 42 had elevated serum CEA or CA19-9 (91.3%). For each case the diagnosis of FDG-PET image was compared with that of CT image and the final diagnosis. Results 48 patients were divided into these three groups according to the purposes of FDG-PET; to identify recurrent colorectal cancer by FDG-PET (identification group, n=5), to determine malignancy and disease spread (disease spreading group, n=37), and to evaluate the possibility of surgical intervention in recurrence-confirmed cases (follow-up group, n=6). In the identification group, FDG-PET solely could identify recurrence and indicate operation for 4 cases (7 times). One of three cases shows disease-free survival for 33 months after common iliac replacement operation. In the disease spreading group, 23 cases with localised disease spread by FDG-PET findings were indicated operation, 14 cases with diffused disease spread were judged as contraindication of operation. The median survival period after recurrence of operation series was longer than that of contraindication series (36 months vs 22 months). In the follow-up group, FDG-PET could detect lesions of whole body at one study and one was indicated for salvage operation for liver metastasis. FDG-PET showed to be false-positive in one case and false-negative in three. Totally, the sensitivity of FDG-PET was 95.7% and its accuracy was 94.2%, whereas those of CT were 87.1% and 87.1%, respectively. Conclusion FDG-PET could visualise a malignant lesions at earlier stage, and was an effective modality to evaluate not only disease spread but distant metastasis for recurrence of colorectal cancer. In this study, we first demonstrated that FDG-PET oriented surgical indication has clinical importance for recurrent colorectal cancer.