Optimized method for normal range estimation of standardized uptake values (SUVmax, SUVmean) in liver SPECT/CT images with somatostatin analog [99mTc]-HYNIC-TOC (Tektrotyd)

Background: 99mTc-hydrazinonicotinyl-Tyr3-octreotide ([99mTc]-HYNIC-TOC [Tektrotyd]) is a radiopharmaceutical used for the diagnosis of lesions with overexpression of somatostatin receptors. The purpose of this study was to optimize the method and estimate normal ranges for standardized uptake values of Tektrotyd in healthy livers.Material and methods: An analysis of standardized uptake value (SUVs) normal ranges was performed for images acquired in a selected “healthy group” of 42 patients evaluated for neuroendocrin tumors. The “pathological group” comprised 20 patients with liver lesions detected by scintigraphic imaging. Normal ranges for radiopharmaceutical uptake values were estimated based on the quantitative analysis of images acquired with a GE Healthcare NM/CT 850 gamma camera.Results: The method for healthy liver segmentation in single photon emission computed tomography/computed tomography (SPECT/CT) was optimized. The normal range of SUVs for the liver was: standardized uptake value body weight (SUVbw) max [5.2–14.0] g/mL and standardized uptake value lean body mass (SUVlbm) [3.5–9.5] g/mL. The relative standard error (relative SE) of activity concentration estimated in the phantom study for the largest hot spheres was: ϕ = 37 mm — 5.9%, ϕ = 28 mm— 7.1%, ϕ = 22 mm — 11.4%, and ϕ = 17 mm — 22%.Conclusions: Segmentation in the mid-coronal computed tomography (CT) image, at one-fourth of the height of the liver measured from the top, with a medium-sized volume of interest (VOI) outlined on a given transverse SPECT slice was regarded as the optimal method for estimating normal ranges for standardized uptake values. It is necessary to standardize quantification methods in the SPECT/CT studies. Our work is a step forward in obtaining standardization of SPECT/CT SUV calculationmethods. Calculations for radiopharmaceutical uptake in tumors with volumes smaller than 5 mL are biased with a significant measurement error

The diagnostic value of dual-phase SPECT/CT scintigraphy based on transport kinetics of 99mTc-sestamibi confirmed with histopathological findings in patients with secondary hyperparathyroidism — practical consideration

BACKGROUND: Dual phase 99mTc-sestamibi SPECT/CT preoperative parathyroid scintigraphy (PPS) is seldom discussedin terms of the transport kinetics of the tracer.Objectives: To assess the relationship between the characteristic type of tracer transport in particular PPS and histopathologicalfindings in patients with secondary hyperparathyroidism (sHPT).MATERIAL AND METHODS: The study comprised 27 patients (13 females and 14 males) with sHPT. Based on tracer accumulationin early phase (EP) and delayed phase (DP), the following types of accumulation for PPS(+) lesions were identified: EP(–)/DP(+) (type I), EP(+)/DP(+) (type II), EP(+)/DP(–) (type III). EP(–)/DP(–) (type IV) lesions constituted PPS(–) group invisible inSPECT/CT. Overall, 69 lesions 59 PPS(+) and 10 PPS(–) were evaluated histopathologically.RESULTS: Among SPECT/CT PPS(+), types I, II and III occurred in 9 (15%), 49 (83%), and 1 (2%) lesions, respectively. Thefrequency of histopathological diagnosis of normal and abnormal (APG — adenoma or hyperplasia) parathyroid gland, as wellas non-parathyroid (thyroid, lymph nodes, or fat) lesions differed significantly between type I, II, and III lesions (p = 0.036).APG histopathological diagnosis was significantly more frequent in lesions with type II uptake than in lesions with type I uptake(76% vs. 33%, p = 0.0197). Type II lesions had significantly higher odds for histopathological diagnosis of APG or NPG thantype IV, PPS(–) lesions [odds ratio = 13.1 (95% CI: 2.75 to 63.27)].CONCLUSIONS: For SHP patients evaluated with SPECT/CT PPS accumulation type I is a weak premise for surgeon to findparathyroid pathology. Only persistent 99mTc-sestamibi accumulation in both phases - equivocal with accumulation type II— effectively differentiates parathyroid and non-parathyroid lesions as well as indicates with high probability the presence ofadenoma or hyperplasia. Type III consistent with washout pattern is rare in sHPT

Individualization of Radionuclide Therapies: Challenges and Prospects

The article presents the problems of clinical implementation of personalized radioisotope therapy. The use of radioactive drugs in the treatment of malignant and benign diseases is rapidly expanding. Currently, in the majority of nuclear medicine departments worldwide, patients receive standard activities of therapeutic radiopharmaceuticals. Intensively conducted clinical trials constantly provide more evidence of a close relationship between the dose of radiopharmaceutical absorbed in pathological tissues and the therapeutic effect of radioisotope therapy. Due to the lack of individual internal dosimetry (based on the quantitative analysis of a series of diagnostic images) before or during the treatment, only a small fraction of patients receives optimal radioactivity. The vast majority of patients receive too-low doses of ionizing radiation to the target tissues. This conservative approach provides “radiation safety” to healthy tissues, but also delivers lower radiopharmaceutical activity to the neoplastic tissue, resulting in a low level of response and a higher relapse rate. The article presents information on the currently used radionuclides in individual radioisotope therapies and on radionuclides newly introduced to the therapeutic market. It discusses the causes of difficulties with the implementation of individualized radioisotope therapies as well as possible changes in the current clinical situation

Nuclear medicine training and practice in Poland.

In Poland, nuclear medicine (NM) has been an independent specialty since 1988. At the end of 2013, the syllabus for postgraduate specialization in NM has been modified to be in close accordance with the syllabus approved by the European Union of Medical Specialists and is expected to be enforced before the end of 2014. The National Consultant in Nuclear Medicine is responsible for the specialization program in NM. The Medical Center of Postgraduate Training is the administrative body which accepts the specialization programs, supervises the training, organizes the examinations, and awards the specialist title. Specialization in NM for physicians lasts for five years. It consists of 36 months of training in a native nuclear medicine department, 12 months of internship in radiology, 3 months in cardiology, 3 months in endocrinology, 3 months in oncology, and 3 months in two other departments of NM. If a NM trainee is a specialist of a clinical discipline and/or is after a long residency in NM departments, the specialization in NM can be shortened to three years. During the training, there are obligatory courses to be attended which include the elements of anatomy imaging in USG, CT, and MR. Currently, there are about 170 active NM specialists working for 38.5 million inhabitants in Poland. For other professionals working in NM departments, it is possible to get the title of a medical physics specialist after completing 3.5 years of training (for those with a master's in physics, technical physics or biomedical engineering) or the title of a radiopharmacy specialist after completing 3 years of training (for those with a master's in chemistry or biology). At present, the specialization program in NM for nurses is being developed by the Medical Centre of Postgraduate Education. Continuing education and professional development are obligatory for all physicians and governed by the Polish Medical Chamber. The Polish Society of Nuclear Medicine (PTMN) organizes regular postgraduate training for physicians working in NM. Educational programs are comprehensive, covering both diagnostics and current forms of radioisotope therapy. They are aimed not only at physicians specialized/specializing in NM, but also at other medical professionals employed in radionuclide departments as well as physicians of other specialties.5 halama

Patient-specific dosimetry of 99mTc-HYNIC-Tyr3-Octreotide in children

Background: Technetium-99m-hydrazinonicotinamide-Tyr3-octreotide (99mTc-HYNIC-TOC) is recognized as a promising radiopharmaceutical for diagnosing neuroendocrine tumors (NETs). However, 99mTc-HYNIC-TOC dosimetry has been investigated only for adults. As pediatric radionuclide therapies become increasingly common, similar dosimetric studies for children are urgently needed. The aim of this study is to report personalized image-based biodistributions and dosimetry evaluations for children studies performed using 99mTc-HYNIC-TOC and to compare them with those from adult subjects. Eleven children/teenage patients with suspected or diagnosed NETs were enrolled. Patient imaging included a series of 2–3 whole-body planar scans and SPECT/CT performed over 2–24 h after the 99mTc-HYNIC-TOC injections. The time-integrated activity coefficients (TIACs) were obtained from the hybrid planar/SPECT technique. Patient-specific doses were calculated using both the voxel-level and the organ-level approaches. Estimated children doses were compared with adults’ dosimetry. Results: Pathologic uptake was observed in five patients. TIACs for normal organs with significant uptakes, i.e., kidneys, spleen, and liver, were similar to adults’ TIACs. Using the voxel-level approach, the average organ doses for children were 0.024 ± 0.009, 0.032 ± 0.017, and 0.017 ± 0.007 mGy/MBq for the kidneys, spleen, and liver, respectively, which were 30% larger than adults’ doses. Similar values were obtained from the organ-level dosimetry when using OLINDA with adapted organ masses. Tumor doses were 0.010–0.024 mGy/MBq. However, cross-organ contributions were much larger in children than in adults, comprising about 15–40% of the total organ/tumor doses. No statistical differences were found between mean doses and dose distributions in patients with and without pathologic uptakes. Conclusion: Although the children TIACs were similar to those in adults, their doses were about 30% higher. No significant correlation was found between the children’s doses and their ages. However, substantial inter-patient variability in radiotracer uptake, indicating disparity in expression of somatostatin receptor between different patients, emphasizes the importance and necessity of patient-specific dosimetry for clinical studies.Medicine, Faculty ofNon UBCRadiology, Department ofReviewedFacult