Early detection of response to imatinib therapy for gastrointestinal stromal tumor by using 18F-FDG-positron emission tomography and computed tomography imaging

A 41-year old female with metastatic gastrointestinal stromal tumor was referred to 18F-FDG-positron emission tomography and computed tomography （PET/CT） scan before and after one-month treatment with imatinib （Glivec, Gleevec, Novartis, Basel, Switzerland）, a tyrosine kinase inhibitor （400 mg/d）. Metabolic response was evaluated before and after one month of therapy. The decrease of the maximum standardised uptake value （SUV） was 79% （from 9.8 to 2.1）. Positron emission tomography demonstrated complete metabolic response after one-month of imatinib treatment. Additionally, the previous lesion was compared with the coronal computerized tomographic image. There was no difference in the size of the tumor before and after therapy according to CT images. However, metabolic activity was inhibited. 18F-FDG-PEr is a valuable method for the detection of response to one-month imatinib treatment in patients with gastrointestinal stromal tumors.

Effect of sunitinib on metastatic gastrointestinal stromal tumor in patients with neurofibromatosis type 1: A case report

Gastrointestinal stromal tumor （GIST） represents the most common mesenchymal malignancy of the gastrointestinal （GI） tract. In neurofibromatosis （NF）, the increased incidence of tumor needs to be considered even in non-symptomatic individuals. Patients with neurofibromatosis NF type 1 have an increased risk of developing GI tumors including rare types such as GIST. We report a case of GIST in a 53-year-old male patient with neurofibromatosis. The patient was diagnosed with NF four years ago and his medical history revealed that he was hospitalized 5 times with a provisional diagnosis of massive lower gastrointestinal bleeding. GIST was diagnosed at explorative laparotomy and the tumor was 21 cm × 13 cm × 7 cm in size. Immunohistochemical examination showed that vimentin, actin and CDl17 were positive. Computerized tomography showed peritoneal implants three months later. Imatinib mesylate （600 mg/d） was initiated. However, control computerized tomography revealed liver and omental metastasis. The dosage was elevated to 800 mg/d. Despite high dosage, the progression of the metastatic lesions continued in the liver and omentum. The patient started oral sunitinib malate （Sutent~ Pfizer Inc, New York, NY, USA） 50 mg per day for 4 consecutive weeks, followed by 2 wk off per treatment cycle. The metastatic lesions in the liver and omentum were decreased in size after four courses, suggesting that sunitinib is also an effective treatment modality for metastatic GIST in NF patients.

Leptin levels in the differential diagnosis between benign and malignant ascites

AIM： To evaluate the role of leptin levels in the differentia diagnosis of ascites. METHODS： Ascitic leptin, TNFα and serum leptin levels were measured in 77 patients with ascites （35 with malignancies, 30 cirrhosis and 12 tuberculosis）. Control serum samples were obtained from 20 healthy subjects. Leptin and TNFα levels were measured by EUSA. Body mass index （BMI） and percentage of body fat （BFM） by skin fold measurement were calculated for all patients and control groups. Peritoneal biopsy, ascites cytology and cultures or biochemical values were used for the diagnosis of patients. RESULTS： In patients with malignancies, the mean serum and ascites leptin levels and their ratios were significantly decreased compared to the other patient groups and controls. In tuberculosis peritonitis, ascitic fluid TNFα levels were significantly higher than malignant ascites and cirrhotic sterile ascites. BMI and BFM values did not distinguish between patients and controls. CONCLUSION： In patients with malignant ascites, levels of leptin and TNFα were significantly lower than in patients with tuberculous ascites.