Makiko Murota

Detection of gastric cancer using 18F-FLT PET: comparison with 18F-FDG PET.

PurposeWe prospectively investigated the feasibility of 3′-deoxy-3′-18F-fluorothymidine (FLT) positron emission tomography (PET) for the detection of gastric cancer, in comparison with 2-deoxy-2-18F-fluoro-d-glucose (FDG) PET, and determined the degree of correlation between the two radiotracers and proliferative activity as indicated by Ki-67 index.MethodsA total of 21 patients with newly diagnosed advanced gastric cancer were examined with FLT PET and FDG PET. Tumour lesions were identified as areas of focally increased uptake, exceeding that of surrounding normal tissue. For semiquantitative analysis, the maximal standardized uptake value (SUV) was calculated.ResultsFor detection of advanced gastric cancer, the sensitivities of FLT PET and FDG PET were 95.2% and 95.0%, respectively. The mean (±SD) SUV for FLT (7.0 ± 3.3) was significantly lower than that for FDG (9.4 ± 6.3 p < 0.05). The mean FLT SUV and FDG SUV in nonintestinal tumours were higher than in intestinal tumours, although the difference was not statistically significant. The mean (±SD) FLT SUV in poorly differentiated tumours (8.5 ± 3.5) was significantly higher than that in well and moderately differentiated tumours (5.3 ± 2.1; p < 0.04). The mean FDG SUV in poorly differentiated tumours was higher than in well and moderately differentiated tumours, although the difference was not statistically significant. There was no significant correlation between Ki-67 index and either FLT SUV or FDG SUV.ConclusionFLT PET showed as high a sensitivity as FDG PET for the detection of gastric cancer, although uptake of FLT in gastric cancer was significantly lower than that of FDG.

Early Assessment of Therapeutic Response using FDG PET in Small Cell Lung Cancer

PurposeWe evaluated the ability of 2-deoxy-2-18F-fluoro-d-glucose (FDG) positron emission tomography (PET) in the early assessment of therapeutic response in patients with small cell lung cancer (SCLC).ProceduresFDG PET studies were performed before (baseline PET), after the first cycle of chemotherapy (early PET), and after completion of therapy (final PET) in 12 patients with SCLC. The standardized uptake value (SUVmax) was measured. Metabolic response was defined as a reduction in SUVmax of more than 20% on the early PET, compared with the baseline PET. Tumor response after completion of therapy was evaluated according to the Response Evaluation Criteria in Solid Tumors (RECIST).ResultsEleven patients were classified as metabolic responders and had a mean (±SD) reduction in SUVmax of 57.9 ± 10.3%. The remaining one patient was classified as a metabolic nonresponder with a reduction in SUVmax of 13.5%. In all patients, metabolic response after the first cycle of chemotherapy was associated with subsequent response according to RECIST.ConclusionsFDG PET has the potential to identify the therapeutic response in patients with SCLC as early as after the first cycle of chemotherapy.

Evaluation of subsubsegmental pulmonary arteries of the posterior and anterior segments of the right upper lobe using multidetector row computed tomography with multiplanar reconstruction images

PurposeWe evaluated the patterns of subsubsegmental pulmonary arteries of the right upper lobe (posterior segment: S2; anterior segment: S3) with multiplanar reconstruction (MPR) images by multidetector row computed tomography (MDCT).Materials and methodsA total of 64 patients who had undergone MDCT scans were included in the study. The subsubsegmental arteries were named by adding “i” or “ii” as the superior or the inferior branch, respectively, of the subsegmental arteries. The subsubsegmental arteries of S2 (A2ai, A2aii, A2bi, A2bii) and S3 (A3ai, A3aii, A3bi, A3bii) were evaluated as arising from either the recurrent artery (RA) or the ascending artery (AA).ResultsA2ai originated from the RA and AA in 43 and 21 patients, respectively. The corresponding numbers were 32 each for A2aii; 28 and 36 for A2bi; 23 and 41 for A2bii; 60 and 4 for A3ai; 43 and 21 for A3aii; 59 and 5 for A3bi; and 54 and 10 for A3bii.ConclusionThe branching pattern of the subsubsegmental pulmonary arteries in the right upper lobe (S2 and S3) could be visualized using MDCT with MPR images.

Pulmonary Multiloculated 'Lotus Torus-like' Sarcoidosis Mimicking Lung Adenocarcinoma

A 34-year-old Japanese woman exhibited a 35×25-mm solitary multiloculated mass shadow in the left lower lobe mimicking lung adenocarcinoma. On computed tomography, the mass resembled a lotus torus. A transbronchial lung biopsy and mediastinal lymph node biopsy led to the diagnosis of sarcoidosis. This lotus torus-like mass regressed spontaneously. This is the second reported case of pulmonary cavitary sarcoidosis with a ‘lotus torus-like’ appearance. We propose several findings regarding the lotus torus-like appearance by comparing the findings to those of lung adenocarcinoma. Knowledge of this unique sign may be helpful for the differential diagnosis of pulmonary sarcoidosis from lung adenocarcinoma.

A case of pulmonary sclerosing hemangioma surrounded by giant cystic change on high-resolution computed tomography.

Pulmonary sclerosing hemangioma is a rare benign neoplasm, usually presenting as a well-defined round or oval mass. We report a case of pulmonary sclerosing hemangioma surrounded by an unusual giant cystic change on high-resolution computed tomography, which led to the suspicion of this tumor.