The Role of 18F-FDG PET/CT in the Primary Staging of Gastric Cancer.

OBJECTIVE: The aim of this study is to explore the role of 18F-FDG PET/CT in the primary staging of gastric cancer in the comparison of ceCT as routine staging method and evaluate influencing parameters of 18F-FDG uptake. METHODS: Thirty-one patients (mean age: 58.9±12.6) who underwent 18F-FDG PET/CT for primary staging of gastric cancer between June 2011 and June 2012 were included to the study. 18F-FDG PET/CT findings were compared with pathological reports in patients who underwent surgery following PET/CT. 18F-FDG PET/CT findings of primary lesions, lymph nodes and adjacent organs were compared with ceCT findings and pathological reports. Since 6 patients were accepted as inoperable according to 18F-FDG PET/CT and/or ceCT and/or laparotomy and/or laparoscopy findings, pathological confirmation could not be possible. RESULTS: In the postoperative TNM staging of patients, while 1 (4%), 1 (4%), 4 (16%), 2 (8%), 12 (48%) and 5 (20%) patients were staged as T0, Tis, T1, T2, T3 and T4, respectively, 8 (32%), 6 (24%), 6 (24%) and 5 (20%) patients were N0, N1, N2 and N3 respectively. 18F-FDG PET/CT was totally normal in 2 patients. While primary tumors were FDG avid in 27 patients, in 17 and 6 patients FDG uptake was observed in perigastric lymph nodes and distant organs, respectively. Mean SUVmax of FDG avid tumors was calculated as 13.49±9.29 (3.00-44.60). However, SUVmax of lymph nodes was computed as 9.28±6.92 (2.80-29.10). According to sub-analysis of histopathological subtypes of primary tumors, SUVmax of adenocarsinomas was calculated as 15.16 (3.00-44.60), of signet ring cells as 9.90 (5.50-17.70), of adenocarcinomas with signet ring cell component as 11.27 (6.20-13.90) (p=0.721). In the comparison with histopathological examination while ceCT was TP, TN, FN in 23, 1 and 1 patients, 18F-FDG PET/CT was TP, FP, FN in 20, 1 and 4 patients, respectively. Sensitivity, specificity, accuracy, PPD and NPV of ceCT in the detection of lymph node metastasis was calculated as 83.3%, 75%, 80%, 87.5% and 66.6%, respectively. These parameters for 18F-FDG PET/CT were 64.7%, 100%, 76%, 100% and 57.1%. CONCLUSION: Despite lower sensitivity than ceCT, diagnostic power of 18F-FDG PET/CT in the preoperative staging of gastric cancer is acceptable. Because of its high PPV, it might be beneficial in the evaluation of patients with suspected lymph nodes. The role of 18F-FDG PET/CT seems to be limited in the early stage and signet ring cell carcinomas due to lower 18F-FDG uptake.

Pelvic perfusion for locally recurrent unresectable rectal tumors.

BACKGROUND/AIMS: Pelvic perfusion evolved as a palliative and curative treatment modality for advanced pelvic tumors and literature data support its use in different steps of the disease. METHODOLOGY: 15 patients with recurrent rectal tumor, without any systemic metastases were included in the study. Mean age was 49.7 years, 12 males, 3 females. Mean survival was 18 months. RESULTS: 15 unresectable rectal cancer patients were included in this study. Three (20%) complete response, 6 (40%) partial response, 2 stable disease (13.3%) and 4 (26.7%) progression were seen after pelvic perfusion. Mean survival is 26.54 months after perfusion (median=10). In multivariate analysis response rate to isolated perfusion and tumor size are significant factors effecting survival (p<0.05). The patients who did not receive chemotherapy after detection of pelvic recurrence did better (p=0.0086). Response to isolated pelvic perfusion (IPP) is an important factor for survival of locally advanced rectal tumors in log-rank test (p=0.0001). CONCLUSIONS: Isolated pelvic perfusion is a good alternative for non-resectable pelvic malignancies and should be considered as an important part of the multidisciplinary approach for these tumors.

Regional chemotherapy for advanced pancreatic carcinoma.

BACKGROUND/AIMS: Since 1990, 14 patients with advanced pancreatic cancer were treated by regional chemotherapy. Five patients had locally advanced unresectable cancer and 9 had locally advanced disease with liver metastasis. METHODOLOGY: Fourteen patients underwent laparotomy, splenic artery catheterization and received a mean therapy of 3.8 cycles and 3 patients had completed 6 cycles of chemotherapy. Every cycle given monthly consisted of 5-fluorouracil 600 mg/m2 3 days, mitomycin 10 mg/m2 1 day, and cisplatinum 60 mg/m2 1 day. Tumor response was evaluated on the basis of imaging methods, tumor markers and life quality marker pain relief. RESULTS: Four patients had stabilization, 4 had partial response, 5 had progression and 1 had complete response. Median survival was 8 months for the whole group. Palliation for pain was successful and 71.4% of the patients had pain palliation. One patient had complete, 1 patient had partial, 8 patients had stable pain relief. Four patients had poor response to treatment and had progressive pain. Side effects, mainly leukopenia and thrombocytopenia, occurred in 5 patients and responded to medical measures. Mild to moderate nausea and vomiting was common and they responded well to antiemetic treatment. CONCLUSIONS: Although the objective response rate of regional chemotherapy for overall survival is low, in an individual patient it may produce an adequate response and acceptable toxicity so that the patient experiences overall improvement in symptoms, and rarely as in one case in our group may be cured by this method.