Koiku Yokoe

Contribution of whole body FDG-PET to the detection of distant metastasis in pancreatic cancer.

Objective: Accurate baseline staging is necessary to appropriately treat pancreatic cancer. The present study was undertaken to evaluate the clinical contribution of whole body FDG-PET to the detection of distant metastasis in pancreatic cancer.Methods: A total of consecutive 42 patients with previously untreated pancreatic cancer were examined. Whole body FDG-PET imaging for initial staging was performed with a 3D acquisition and iterative reconstruction on Siemens ECAT HR+ scanner at 1 hour post 185-200 MBq18F-FDG injection. PET findings were correlated with clinical and radiological data to determine the impact of PET on staging.Results: In 16 patients, there were one or more sites of metastasis based on clinical data. FDG-PET correctly identified the presence of metastasis in 13 of 16 patients and its absence in 23 of the remaining 26 patients. Thus, FDG-PET missed 4 metastatic sites in 4 patients (liver and lung metastasis). FDG-PET correctly identified 8 metastatic sites in 7 patients (peritoneal dissemination and liver, bone and supracla-vicular lymph node metastasis), which were missed on CT imaging. Based on whole body FDG-PET, the clinical stage was changed in 5 of 42 patients (11.9%).Conclusions: These results suggest that FDG-PET and CT appear to have a complementary role in the detection of distant metastasis in patients with pancreatic cancer.

FDG PET as a procedure for detecting simultaneous tumours in head and neck cancer patients.

AimThe presence of simultaneous primary tumours in other regions affects the prognosis and management decisions of head and neck cancer patients. Therefore, early detection of these tumours is necessary. Recent improvements in positron emission tomography (PET) have made it possible to examine the patients whole body. The present study was undertaken to evaluate the clinical contribution of whole-body PET using fluorodeoxyglucose (FDG) for head and neck cancer patients. MethodsFifty-three consecutive patients with previously untreated head and neck cancer were examined. Whole-body FDG PET imaging was performed at 1 h after injection of 18F-FDG. A 3-D acquisition was undertaken and iterative reconstruction was performed. The final diagnosis of simultaneous primary tumour was established by histological findings or clinical follow-up. ResultsOf 53 patients, six (11%) had evidence of simultaneous primary tumour. In five of these six patients, simultaneous primary tumours (two gastric cancer; one colon cancer; one pancreatic cancer; one thyroid cancer) were found by FDG PET. One more patient was found to have prostate cancer on the basis of blood test but this was not detected by FDG PET. In none of the remaining 47 patients, were additional simultaneous primary tumours found by FDG PET or any of the other routine examinations or during follow-up. ConclusionsThe results of this study show a high rate of simultaneous primary tumour in patients with primary head and neck cancer. FDG PET appears to be a promising imaging modality for the detection of simultaneous tumours in head and neck cancer patients.

Usefulness of FDG-PET imaging for the radiotherapy treatment planning of pyothorax-associated lymphoma

Pyothorax-associated lymphoma (PAL) is a non-Hodgkin’s lymphoma developing in the pleural cavity after a long-standing history of chronic pyothorax (CP). F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) imaging is a useful modality for determination of disease extent of various malignant tumors, including malignant lymphoma, but there have been no reports describing the usefulness of FDG-PET imaging in PAL. Here we report a case of PAL that relapsed after chemotherapy and was successfully treated by radiotherapy. FDG-PET imaging revealed that the tumor was localized to a soft-tissue attenuation mass behind the CP cavity in the right thorax, but did not infiltrate the CP cavity. A total dose of 40 Gy was administered to the area that included the PET-positive lesion, instead of including the entire CP cavity in the radiation field. Although computed tomography (CT) showed a residual mass, no FDG uptake was indicated by FDG-PET imaging performed just after the end of radiotherapy, and additional irradiation was not performed. No sign of relapse was found by FDG-PET imaging 3 months later. FDG-PET imaging was useful for both the planning of radiotherapy and assessing the treatment response of PAL.

Diagnosis of thyroid lymphoma and follow-up evaluation using Ga-67 scintigraphy

A strong association between malignant lymphoma and Hashimotos thyroiditis has frequently been reported. However, it is difficult to detect the lymphomatous transformation of Hashimotos thyroiditis in the early stage. The purpose of the present study was to examine the usefulness of67Ga scintigraphy in the diagnosis and evaluation of the therapeutic effects during follow-up, in patients with a suspected diagnosis of primary thyroid lymphoma. Twenty-five patients who were suspected of having primary thyroid lymphoma and had undergone67Ga scintigraphy were studied.67Ga planar scintigraphy was performed 72 hours after injection of67Ga-citrate. The degree and pattern of67Ga accumulation were graded visually. Histopathology on biopsy examination revealed thyroid lymphoma in 17 and Hashimotos thyroiditis in 8 patients. Abnormal accumulation of67Ga in the thyroid was seen in all of the 17 thyroid lymphoma cases with additional mediastinal and abdominal involvement in one. Fifteen of 17 thyroid lymphoma patients also underwent67Ga scintigraphy 2–4 weeks after chemotherapy and/or radiotherapy. All 15 patients showed diminishing67Ga accumulation and a good clinical course. In one patient with local recurrence, abnormal accumulation could be depicted by follow-up scintigraphy. However, diffuse or enlarged accumulation in the thyroid was seen in all of the 8 Hashimotos thyroiditis cases. The degree of abnormal accumulation in the thyroid in clinically active phase thyroiditis was more intense than that in the chronic phase thyroiditis.67Ga scintigraphy was helpful to confirm the diagnosis of thyroid lymphoma and to evaluate the therapeutic effects during follow-up. However,67Ga scintigraphy may not always distinguish thyroid lymphoma from Hashimotos thyroiditis, especially the active phase of the disease.

Unknown primary carcinoma, diagnosed as inflammatory breast cancer,and successfully treated with trastuzumab and vinorelbine.

Occult breast cancer presenting with axillary lymph node metastases is uncommon, and inflammatory breast cancer (IBC), as a subtype, is quite rare. Here we describe a case of IBC, which arose as an unknown primary carcinoma; the patient presented with axillary lymph node metastasis, and was successfully treated with trastuzumab and vinorelbine. Specifically, a 55-year-old woman presented with right axillary lymphadenopathy. Although she underwent various examinations, the primary site of the disease was not revealed. Axillary lymph node dissection was performed, and the lesion was diagnosed as a poorly differentiated adenocarcinoma. The patient chose to be treated by alternative medicine. About 6 months later, she was referred to our hospital, due to marked bilateral neck and axillary lymph node swelling. She presented withdiffuse right breast enlargement, redness, and peau d’orange. Computed tomography (CT) of the breast showed skin thickening and swelling of the right breast.F-18 Fluorodeoxyglucose positron emission tomography (FDG-PET) showed FDG uptake in the right breast. The patient was clinically diagnosed with IBC. Because overexpression of the human epidermal growth factor receptor 2 (HER2) was found in the specimen from her right axillary lymph node, she was treated with trastuzumab and vinorelbine. Two months after the start of chemotherapy, CT revealed a complete response in the lymph nodes, and the skin thickening and parenchymal edema of the right breast had improved. FDG-PET was also performed at this time, and revealed no FDG uptake in either the right breast or the lymph nodes.

Superimposed dual-isotope SPECT using99mTc-hydroxymethylene diphosphonate and201Tl-chloride to assess cartilage invasion in laryngohypopharyngeal cancer

ObjectiveCartilage invasion in laryngohypopharyngeal cancer has a significant impact on the choice of treatment modality and outcome of the disease. We examined invasion of cartilage in laryngohypopharyngeal cancer by simultaneous bone and tumor dual-isotope SPECT using99mTc-hydroxymethylene diphosphonate and20lTl-chloride.MethodsEarly and delayed simultaneous bone and tumor dual-isotope SPECT were performed on 19 patients with laryngohypopharyngeal cancer. Dual-isotope SPECT images were superimposed to project tumor location from tumor SPECT onto the osseous structures shown by bone SPECT. The presence or absence of cartilage invasion was evaluated histopathologically or by radiological studies such as CT and/or MRI.ResultsHistopathological or radiological examination of the cartilage revealed invasion in 5 patients and no invasion in 14 patients. The results of both early and delayed dual-isotope SPECT were exactly the same. Using dual-isotope SPECT, the sensitivity, specificity, and accuracy in detecting cartilage invasion by laryngohypopharyngeal cancer were: 80% (4/5), 92.9% (13/14), and 89.5% (17/19), respectively.ConclusionsResults of the present study suggest that superimposed early bone and tumor dual-isotope SPECT images may be sufficient for the diagnostic evaluation of cartilage invasion by laryngohypopharyngeal cancer. Superimposed dual-isotope SPECT imaging is a useful technique in the evaluation of cartilage invasion in laryngohypopharyngeal cancer.

A comparative study of2O1T1 scintigraphy and three-phase bone scintigraphy following therapy in patients with bone and soft-tissue tumors

Objective: The purpose of this study was to evaluate the usefulness of201T1 scintigraphy in comparison with three-phase bone scintigraphy in the differentiation of residual/recurrent tumors from post-therapeutic changes, in patients previously treated for bone and soft-tissue tumors.Methods: Thirty-five201T1 and three-phase bone scintigraphy scans were obtained for 30 patients with a history of bone or soft-tissue tumor who had undergone chemotherapy, radiation therapy, tumor resection, or a combination of these treatments. The planar201Tl images were acquired 10 mins (early) and 2 hrs (delayed) after the intravenous injection of 111 MBq201Tl-chloride. Three-phase bone scintigraphy was performed using 740 MBq99mTc-HMDP at the same lesion site as for201T1 imaging. The blood flow images were obtained every 10 sec for 2 mins and were immediately followed by the blood pool image after 5 mins. Three to 4 hrs later, bone images were obtained.201Tl and three-phase bone scintigraphies were correlated with the histopathologic findings and/or clinical follow-up of more than 3 months.Results: Of the 35 cases, 15 were free of disease and 20 had residual or recurrent tumors. Of the 20 residual or recurrent cases, all had true-positive201T1 early and delayed scans, while bone scintigraphy was true-positive on the blood flow, blood pool and bone images in 16, 18 and 12 cases, respectively.201T1 early and delayed images and99mTc-HMDP blood flow and blood pool images were false-positive in one patient. The histology of this false-positive case showed the presence of lymph proliferative tissue.Conclusions: Although201Tl uptake after treatment does not always indicate recurrence,201T1 scintigraphy may still be more useful than three-phase bone scintigraphy in the follow-up of patients with bone and soft-tissue tumors following therapy.