The factors that make BS inconclusive do not affect (18)F-fluoride PET/CT which shows a high sensitivity and negative predictive value for excluding bone metastases even in patients with inconclusive conventional BS.

Radiofármacos são produzidos e distribuídos no Brasil há mais de 40 anos pelos Institutos da Comissão Nacional de Energia INTRODUÇÃORadiofármacos podem ser definidos simplesmente como substratos que contêm um átomo radioativo em sua estrutura, podendo ser considerados como vetores que apresentam certa especificidade por algum órgão ou uma função fisiológica ou fisiopatológica. Por sua forma farmacêutica, quantidade e qualidade da radiação emitida, podem ser utilizados com finalidade diagnóstica ou terapêutica, qualquer que seja a via de administração empregada

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OBJECTIVES:Cancer has been investigated using various pre‐targeting techniques or models focusing on radiobombesin analogues; however, both are not offered together. In this study, nano‐bombesin labeling by a pre‐targeting system was undertaken to develop an alternative approach for prostate tumor treatment.METHODS:A two‐step pre‐targeting system utilizing a combination of streptavidin (SA), biotinylated morpholino (B‐MORF), biotinylated BBN (B‐BBN) with two different spacers (β‐Ala and PEG), and a radiolabeled cMORF was evaluated in vitro and in vivo.RESULTS:Final conjugation conditions consisted of a 1:1:2 ratio of SA:B‐MORF:B‐BBN, followed by addition of 99mTc‐cMORF to compensate for free MORF. In vitro binding experiments with prostate cancer cells (PC‐3) revealed that total binding was time‐dependent for the Ala spacer but not for the PEG spacer. The highest accumulation (5.06±1.98 %) was achieved with 1 hour of incubation, decreasing as time progressed. Specific binding fell to 1.05±0.35 %. The pre‐targeting biodistribution in healthy Swiss mice was measured at different time points, with the best responses observed for 7‐h and 15‐h incubations. The effector, 99mTc‐MAG3‐cMORF, was administered 2 h later. Strong kidney excretion was always documented. The greatest tumor uptake was 2.58±0.59 %ID/g at 7 h for B‐βAla‐BBN, with a region of interest (ROI) value of 3.9 % during imaging. The tumor/blood ratio was low due to the slow blood clearance; however, the tumor/muscle ratio was 5.95.CONCLUSIONS:The pre‐targeting approach with a peptide was a viable concept. Further evaluation with modified sequences of MORF, including less cytosine, and additional test intervals could be worthwhile.

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To compare the use of 740 Mbq (20 mCi) of (153) Sm and 185 Mbq (5mCi) of (90) Y, both labelling hydroxyapatite (HA), for knee synovectomy in haemophilic patients, 1 year after the intervention. Thirty three men (36 knees) were studied, divided into two groups: 1 - treatment using 740 Mbq of (153) Sm-HA: 20 knees of 18 patients, with mean age of 21.4 ± 13.3 years (ranging from 7 to 56 years) and mean Pettersson score of 5.3; 2 - treatment using 185 Mbq of (90) Y-HA: 16 knees of 15 patients, with mean age of 26.3 ± 10.3 (ranging from 7 to 51 years) and mean Pettersson score of 6.3. The following criteria were adopted for the evaluation before and 1 year after synovectomy: reduction in haemarthrosis episodes and pain using a visual analogue scale, as well as improved joint mobility. The occurrence of adverse events in the treatment was also considered. The chi-square, Wilcoxon and Mann-Whitney tests were used with P ≤ 0.05 set as significant. The occurrence of haemarthrosis declined by 65.7% with the use of (153) Sm-HA and 82.6% for (90) Y-HA, with no statistical difference between the groups (P = 0.632); pain reduction was 42.5% in group 1 and 30.7% in group 2, once again with no statistical difference (P = 0.637). Improvement in joint mobility was not significant for both groups. Two cases of mild reactive synovitis were observed in group 1 and one in group 2, which cleared up without medical intervention. Although the beta energy from (90) Y is the gold standard for knee synovectomy, higher activities of (153) Sm may be used in places which have only production of this material.

ObjectiveTo evaluate SPECT/CT with radiolabeled somatostatin analogues (RSAs) in systemic granulomatous infections in comparison with gallium-67 (67Ga) citrate scintigraphy.Materials and MethodsWe studied 28 patients with active systemic granulomatous infections, including tuberculosis, paracoccidioidomycosis, pneumocystosis, cryptococcosis, aspergillosis, leishmaniasis, infectious vasculitis, and an unspecified opportunistic infection. Of the 28 patients, 23 had started specific treatment before the study outset. All patients underwent whole-body SPECT/CT imaging: 7 after injection of 99mTc-EDDA-HYNIC-TOC, and 21 after injection of 111In-DTPA-octreotide. All patients also underwent 67Ga citrate imaging, except for one patient who died before the 67Ga was available.ResultsIn 20 of the 27 patients who underwent imaging with both tracers, 27 sites of active disease were detected by 67Ga citrate imaging and by SPECT/CT with an RSA. Both tracers had negative results in the other 7 patients. RSA uptake was visually lower than 67Ga uptake in 11 of the 20 patients with positive images and similar to 67Ga uptake in the other 9 patients. The only patient who did not undergo 67Ga scintigraphy underwent 99mTc-EDDA-HYNIC-TOC SPECT/CT-guided biopsy of a lung cavity with focal RSA uptake, which turned to be positive for aspergillosis.ConclusionSPECT/CT with 99mTc-EDDA-HYNIC-TOC or 111In-DTPA-octreotide seems to be a good alternative to 67Ga citrate imaging for the evaluation of patients with systemic granulomatous disease.