We aimed to assess the additional value of SPECT/CT over planar lymphoscintigraphy (PI) in sentinel node (SN) detection in malignancies with different lymphatic drainage such as breast cancer, melanoma, and pelvic tumors. Methods: From 2010 to 2013, 1,508 patients were recruited in a multicenter study: 1,182 breast cancer, 262 melanoma, and 64 pelvic malignancies (prostate, cervix, penis, vulva). PI was followed by SPECT/CT 1-3 h after injection of 99m Tccolloid particles. Surgery was performed the same or next day. Results: Significantly more SNs were detected by SPECT/CT for breast cancer (2,165 vs. 1,892), melanoma (602 vs. 532), and pelvic cancer (195 vs. 138), all P , 0.001. The drainage basin mismatch between PI and SPECT/CT was 16.5% for breast cancer, 11.1% for melanoma, and 51.6% for pelvic cancers. Surgical adjustment was 17% for breast cancer, 37% for melanoma, and 65.6% for pelvic cancer. Conclusion: SPECT/CT detected more SNs and changed the drainage territory, leading to surgical adjustments in a considerable number of patients in all malignancies studied but especially in the pelvic cancer group because of this group's deep lymphatic drainage. We recommend SPECT/CT in all breast cancer patients with no SN visualized on PI, all patients with melanoma of the head and neck or trunk, all patients with pelvic malignancies, and those breast cancer and melanoma patients with unexpected drainage on PI. The status of regional lymph nodes is a major prognostic factor in many malignant tumors. Sentinel lymph node (SN) biopsy in patients with clinically node-negative tumors is a validated technique for accurate staging of nodal disease in breast cancer (1,2) and melanoma (3,4) and is being used with promising results in other solid tumors including pelvic malignancies (5,6). The use of SN mapping in an increasing list of tumors shows a variety of lymphatic drainage basins containing the SN (7). SNs are the lymph nodes draining the primary tumor and therefore the most likely to contain tumor cells spreading to the drainage basin (8). Assuming an orderly progression of lymph flow, the tumor status of the SN predicts the status of the regional draining basin (1). Selective SN biopsy enables the detection of metastatic and occult micrometastatic nodal involvement by thorough histopathologic examination in the intraoperative setting, sparing patients a systematic regional lymphadenectomy when the node is negative.Planar lymphoscintigraphy (PI) after local injection of radiocolloid is well suited for the mapping of regional lymph nodes, but occasionally no SNs are visualized, for instance, in obese patients or when SNs are located too close to the injection site. In addition, the anatomic information provided by planar scintigraphy is limited and the exact SN location is difficult to define in deeply located nodes (9,10). Unexpected basin drainage sites and unpredictable pathways also hinder interpretation of planar images. Because of its superior contrast, resolution, and display of exact anatomic landmarks, SPECT...

An EU twinning project entitled 'Strengthening of administrative structures for radiation protection and safe use of ionising radiation in diagnostics and therapy' was established between Bulgaria and Finland, lasting from June 2008 to May 2009. One component of the project was to improve the optimisation of patient protection in nuclear medicine (NM) through revising diagnostic reference levels (DRLs). The revised DRLs are based on national surveys on the numbers of NM procedures and activities given to the patients in different procedures. The survey in Bulgaria was carried out in 2008 and that in Finland in 2007. National DRLs were established for the most frequent and dose-relevant examinations. The proposed DRLs in both countries are in good agreement with other national recommendations in Europe.

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Objectives: The aim of the study was to investigate the role of 18 fluorine-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) for evaluating the efficacy of radiofrequency ablation (RFA) in primary and metastatic liver tumors compared with contrast-enhanced ultrasound examination (CEUS) and to find its place in overall staging and the follow-up diagnostic algorithm. Methods: PET/CT examinations were performed 2 months after RFA for 20 patients with a total of 34 liver lesions. CEUS was performed within 10 days after PET/CT, and the results were compared. Seven patients were staged with PET/CT and the others with a contrast-enhanced CT. Results: A total of 48 18 F-FDG PET/CT examinations were performed. We observed complete response in 8 patients (40%), 2 patients (10%) had stable disease, one (5%) had partial response, and 9 patients (45%) had progression (including 2 cases with extrahepatic involvement). Compared with CEUS, there was a mismatch in 3 cases. Five patients underwent additional RFA for 7 lesions. Conclusion: According to our preliminary data, PET/CT may be a valuable method, with comparable or eventually even better sensitivity than CEUS, for early evaluation of the efficacy of RFA for the treatment of metastatic and primary liver lesions and planning of future treatment. PET/CT might be recommended as a staging method before undergoing RFA of liver lesions for determining the local extent of the disease in the liver in combination with CEUS with an advantage in visualization of extrahepatic involvement. However, more patients need to be investigated in order to demonstrate and confirm the obtained results with certainty.

Objectives:Radiation pneumonitis (RP) can be an adverse complication of radiotherapy (RT) and can limit the application of the already planned radiation dose. It is often associated with RT of lung carcinoma and is occasionally caused by radiation therapy of breast carcinoma and lymphomas located in the mediastinum. Positron emission tomography/computed tomography (PET/CT) emerges lately as a prospective modality for early diagnostics of RP. The aim of this study was to summarize the initial data from diagnostic application of PET/CT in patients suspicious of RP and to derive criteria, which can help differentiate RP from early recurrence of the disease and/or residual tumor.Methods:The current study included 23 patients who had metabolic (PET) and anatomical (CT) changes consistent with RP. We additionally defined metabolic activity (SUVmax) in the lung parenchyma of 20 patients without RT.Results:All patients had increased metabolic activity in the lung parenchyma involved in the irradiated area with a mean SUVmax 3.45 (ranging between 1 and 7.1). The control group had a physiological background metabolic activity-SUVmax 0.61 +/- 0.11.Conclusion:Metabolic changes in patients suspicious of RP involved diffusely increased metabolic activity coinciding with the anatomical changes in the irradiated area. Three out of 23 patients had a proven recurrence of the primary neoplastic process in the irradiated area. The metabolic changes in those patients involved an increase in metabolic activity at follow-up or lack of tendency towards normalization after chemotherapy, which implied the existence of viable tumor cells. Our initial experience in the diagnostic application of 18F-FDG PET/CT in patients suspicious of RP allows us to summarize the following: PET/CT is a reliable imaging modality in the diagnostics of RP. Through its sequential use, we can differentiate inflammatory changes related to RP from early recurrence of the primary neoplastic process.