Comparison of CT and PET-CT based planning of radiation therapy in locally advanced pancreatic carcinoma

Abstract Background To compare computed tomography (CT) with co-registered positron emission tomography-computed tomography (PET-CT) as the basis for delineating gross tumor volume (GTV) in unresectable, locally advanced pancreatic carcinoma (LAPC). Methods Fourteen patients with unresectable LAPC had both CT and PET images acquired. For each patient, two three-dimensional conformal plans were made using the CT and PET-CT fusion data sets. We analyzed differences in treatment plans and doses of radiation to primary tumors and critical organs. Results Changes in GTV delineation were necessary in 5 patients based on PET-CT information. In these patients, the average increase in GTV was 29.7%, due to the incorporation of additional lymph node metastases and extension of the primary tumor beyond that defined by CT. For all patients, the GTVCT versus GTVPET-CT was 92.5 ± 32.3 cm3 versus 104.5 ± 32.6 cm3 (p = 0.009). Toxicity analysis revealed no clinically significant differences between two plans with regard to doses to critical organs. Conclusion Co-registration of PET and CT information in unresectable LAPC may improve the delineation of GTV and theoretically reduce the likelihood of geographic misses.</p

Hepatobiliary scintigraphy to detect duodenogastric reflux: Intravenous administration of Tc-99m pertechnetate to define the location of the stomach

PubMedID: 11290908A 65-year-old man who had a cholecystectomy 20 years previously and a recent 6-month history of right upper abdominal pain that spread to the back was evaluated for duodenogastric reflux by hepatobiliary scintigraphy. Abnormal activity in two frames suggested duodenogastric reflux. To determine file location of the stomach, intravenous administration of Tc-99m pertechnetate was administered after the hepatobiliary scan. This is a simple method that includes only the intravenous administration of 3 to 5 mCi (111 MBq) Tc-99m pertechnetate and is a good alternative to the oral use of technetium agents, which have a carefully calculated dose adjustment to avoid scatter, and dual-isotope imaging, which requires a second isotope

The value of F-18-fluorodeoxyglucose positron emission tomography/computed tomography in carcinoma of an unknown primary: diagnosis and follow-up

WOS: 000272915000010PubMed ID: 19952921Background The management of the patients with carcinoma of an unknown primary represents a difficult challenge in oncology. F-18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) has provided new insights in the diagnosis, staging, and follow-up of oncological patients. Aim This study aimed to investigate the value of FDG PET/CT in clarifying the primary site in our patients with histologically proven tumor metastasis (HPM) or with a high clinical suspicion of malignancy, and the clinical impact of this technique on the management of these patients. Methods In total 94 patients from two centers underwent FDG PET/CT imaging; 78 patients with HPIVI and 16 patients with a clinical suspicion of malignancy. The histology and/or follow-up data were used as the gold standard. Hypermetabolic findings at the site of the pathological CT changes or at physiological FDG uptake sites were the criteria for malignancy. PET/CT findings were analyzed for the identification of the primary tumor site, for the relationship with survival, and also for the effect in chemotherapy monitoring. Results Primary malignancy was discovered in 53 of 90 patients (59%) histologically and 37 (41%) patients' primary tumor sites were not found during the study period. Amongst 90 patients, five (6%) were normal on FDG PET/CT. Of 85 patients (94%) with pathological findings on FDG PET/CT, 27 patients (32%) had solitary and 58 (68%) patients had multiple organs affected. Regarding the whole study population, a sensitivity of 74% and a specificity of 78% were calculated for FDG PET/CT imaging. Regarding the patients with HPM, the sensitivity and specificity values were 84 and 81%, respectively. The mean survival time of the patients with disseminated disease was significantly shorter than those of the patients with single or no lesion (13.44 +/- 1.61, 20.98 +/- 2.0 and 26.67 +/- 2.73 months, respectively, P = 0.014). In seven of eight patients, follow-up FDG PET/CT scans effectively monitored the patients' therapies. Conclusion Whole-body FDG PET/CT has to be considered a useful method, especially in an early phase of the diagnostic workup of patients with carcinoma of an unknown primary syndrome, to optimize the management. Nucl Med Commun 31:59-66 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins

Tc-99m(V)-DMSA SPECT for the assessment of disease activity in Graves' ophthalmopathy

WOS: 000249773700004PubMed ID: 17728607Objective The aim of this study was to evaluate the use of Tc-99m(V)-dimercaptosuccinic acid (Tc-99m(V)-DMSA) scintigraphy for the assessment of disease activity in patients with Graves' ophthalmopathy (GO) and compare their clinical parameters. Methods The study involved 20 patients who were clinically inactive and eight patients who were clinically active, a total 28 GO patients (18 female, 10 male; mean age: 39.2 +/- 13.4 years) and 12 control subjects (six female, six male; mean age: 57.12 12 years). Planar and SPECT orbital images were obtained 4 h after the intravenous injection of 555-740MBq Tc-99m(V)-DMSA, using low-energy, high-resolution, parallel-hole collimators with dual-head detectors. All SPECT data were reconstructed on conventional axial, sagittal and coronal projections using an iterative reconstruction. Semi-quantitative evaluation was performed comparing the orbital activity with nasal activity based on four grades. GO was classified according to the NOSPECS classification of the American Thyroid Association. Disease was considered clinically active if symptoms and signs deteriorated over 3 months. Results No significant correlation was detected between clinical activity and classification (P=0.192). However, clinical activity and Tc-99m(V)-DMSA uptake were significantly correlated (P=0.0001). There was no correlation between the clinical classification and scintigraphic grading. Bilateral orbital index of the active group was significantly higher than that of the inactive group (P=0.0001). Conclusion Tc-99m(V)-DMSA imaging discriminates the active from inactive GO as well as showing an ongoing subclinical inflammation in the orbits of the patients with GO, regardless of the disease activity clinically. Our results revealed that Tc-99m(V)-DMSA is a promising agent for the diagnosis of active Graves' ophthalmopathy