FDG is the most frequently used positron emission tomography probe but it has certain limitations when used in urological cancers due to its urinary elimination, which prevents the proper visualization of the bladder and kidneys. The introduction of co-registered PET and computed tomography (PET/CT) represents a major advance in technology and now become the new standard for many cancers. For the staging and surveillance of renal cell cancer, FDG PET/ CT had results that were at least as good as conventional methods, which are potentially harmful for the remained renal function. FDG-PET/CT is able to evaluate early response to sunitinib or sorafenib treatment in metastatic renal cell cancer. An early decrease in the mean glucose uptake was found in both soft and skeletal lesions after treatment, thus PET seems to be more advantageous compared with RECIST evaluation. In addition, the survival of patients with advanced renal cell cancer can be predicted by evaluating their SUVmax using FDG-PET/CT. Although urinary bladder cancer demonstrates sufficiently increased FDG uptake, primary tumors are difficult to identify due to the renal excretion of FDG. The accuracy of FDG-PET/CT in metabolically active metastases is generally higher when compared to conventional CT except for identifying small lung deposits. PET/CT with delayed images after a diuretic and oral hydration may improve detection of locally recurrent or residual UBC and could replace standard CT and bone scintigraphy in the presurgical staging and monitoring of patients with urinary bladder cancer. 18F-choline PET may be useful for staging of urinary bladder cancer in addition to FDG PET

A 54-year-old woman was referred to thyroid evaluation because of a lump on the left side of the neck. Ultrasound exam did not show any thyroid abnormality, but highly perfused nodule at the left common carotid artery bifurcation was found. Because of the specific location, somatostatin receptor scintigraphy with Tc EDDA HYNIC-TOC was performed, starting with perfusion images and followed with SPECT/CT imaging at 2 and 4 hours. Well-perfused nodule with intensive accumulation and no other visible pathology in the body raised suspicion of a glomus tumor, consistent with MR exam performed later. Subsequent surgical removal confirmed carotid paraganglioma.

Dose assessment of diagnostic nuclear medicine procedures is necessary to further optimize respective procedure, estimate radiation risk, improve radiation safety and verify compliance of local practice with guidelines. In line with Council Directive 2013/59/EURATOM, patient medical documentation should include information related to radiation exposure. The aim of this work is to present the patient radiation dose assessment system designed for routine clinical use, that uses in-house designed worksheets for dose calculation based on relevant parameters introduced by the ICRP publications. Dose reports provide information about the absorbed dose delivered to the target and non-target organs of interest and the effective dose for each diagnostic procedure. The data from the dose reports was used to investigate average patient exposure levels during a one-year period and the results are presented. The implemented system has improved the quality of services provided and understanding of radiation risks. Moreover, the presented results have stimulated further optimization of nuclear medicine processes.

Summary 99mTc-DMSA scintigraphy is generally accepted as the method of choice for detecting renal parenchymal damage in pyelonephritis. 99mTc-MAG3 dynamic scintigraphy is not routinely used for this purpose. The aim of this study was to evaluate the MAG3 scintigraphic presentation in the acute phase of pyelonephritis in children and re-evaluate them at least 6 months later, as well as to establish whether a MAG3 in the parenchymal phase is as reliable and sensitive in the detection of a renal parenchymal damage as the DMSA. Patients, methods: The MAG3 scintigraphic pattern was evaluated during the first episode of acute pyelonephritis in 31 children (median age: 2.5 years) and compared to the DMSA scan. The scintigraphy was performed on the same day with both radiopharmaceuticals. After at least 6 months the whole procedure was repeated on 28 patients. A scoring system was designed to evaluate the parenchymal lesions, and categorize them as positive or equivocal. The findings on the initial scans were compared to those obtained in the follow up studies. Results: When all lesions (equivocal + positive) were analysed, MAG3 sensitivity was 98%, and specificity 78%, while for positive lesions only, the values were 83 and 100%, respectively. The average acute severity score was significantly lower for both MAG3 and DMSA then the follow up score (p <0.0001). These results corresponded to a clinical convalescence, which was observed in 26/28 children in the follow up. Conclusion: With the MAG3 scintigraphy a reliable semi quantitative and qualitative detection of the renal inflammatory lesions can be obtained in acute pyelonephritis, as well as their recovery, thus obviating the need for a DMSA scan. Moreover, the duration of the MAG3 procedure is shorter, enabling the visualization of the entire collecting system as well, while the radiation exposure is approximately a half of that delivered by the DMSA scan.

Cilj: Cilj rada bio je procijeniti doprinos jednofotonske emisijske tomografije / kompjutorizirane tomografije somatostatinskih receptora (SR SPECT/CT) s 99mTc-EDDA/HYNIC-Tyr3-oktreotidom (99mTc-Tektrotyd) u dijagnostici i procjeni proširenosti bolesti kod pacijenata oboljelih od neuroendokrinih tumora (NET-ova). Ispitanici i metode: Retrospektivno je analizirano 120 SR SPECT/CT snimanja pacijenata s patohistološki dokazanim NET-om s obzirom na vizualizaciju primarnih lezija i metastaza. U 45 pacijenata učinjena je i pozitronska emisijska tomografija 18F-fluorodeoksiglukozom (18F-FDG PET/CT) te su nalazi uspoređeni s nalazima SR SPECT/CT-a i vrijednostima kromogranina A. Rezultati: Od 120 pacijenata 47 (39 %) je na SR SPECT/CT upućeno nakon odstranjenja primarne lezije. Od preostala 73 pacijenta (61 %), u 56 (77 %) primarni je tumor bio vidljiv SR SPECT/CT-om, a u 9 (12 %) poznata lezija nije akumulirala radiofarmak. U 8 (11 %) pacijenata s NET-om nepoznatog primarnog sijela nalaz je bio negativan. Od 68 (57 %) pacijenta s dokazanim metastazama, u njih 57 (84 %) bile su vidljive SR SPECT/CT-om, a u 11 (16 %) nisu akumulirale radiofarmak. Od 45 (38 %) pacijenata kojima je učinjen i 18F-FDG PET/CT, u 27 (60 %) detekcija primarnih lezija i metastaza bila je sukladna nalazu SR SPECT/CT-a. Osjetljivost SR SPECT/CT-a bila je 77 % za primarne lezije i 84 % za metastaze, a 18F-FDG PET/CT-a 75 % za primarne lezije i 76 % za metastaze. Vrijednosti kromogranina A nisu pokazale statistički signifikantnu korelaciju s nalazima slikovne dijagnostike. Zaključci: SR SPECT/CT ima visoku osjetljivost za detekciju NET-ova. Osim toga, potvrđena je komplementarnost s 18F-FDG PET/CT-om te kod pacijenata s negativnim nalazom SR SPECT/CT-a treba učiniti 18F-FDG PET/CT i obrnuto.