Dražen Huić

Radioiodine uptake in thyroid cancer patients after diagnostic application of low-dose 131I

The aim of this study was to investigate the influence of the diagnostic administration of 74 MBq 131I on subsequent uptake of therapeutic radioiodine in thyroid cancer patients. Retention measurements were performed using a whole-body counter in 24 patients 6 weeks after total thyroidectomy. Profile scans were performed 2, 24, 48 and 72 h after the administration of the diagnostic dose and 72 h after the administration of the ablation-therapeutic dose (4.4 GBq). The mean ( +/- S.D.) effective half-life of the diagnostic dose in thyroid remnants was 40.3 +/- 23.0 h. The uptake in the thyroid remnants of the subsequent ablation dose 72 h after administration was 30.4 +/- 19.8% of that predicted from the diagnostic study. The greater reduction in uptake was associated with the longer half-life of iodine and higher uptake in the thyroid remnants at 24 h, with a longer interval between surgery and administration of the diagnostic dose and a shorter period between administration of the diagnostic and ablation doses. Our results show that a diagnostic dose of 74 MBq 131I markedly reduces thyroid uptake of an ablation dose of 131I. This should be taken into account during radiation dose planning whenever a quantitative dosimetric study is to be performed.

Results of a Prospective Multicenter International Atomic Energy Agency Sentinel Node Trial on the Value of SPECT/CT Over Planar Imaging in Various Malignancies

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 99mTc-colloid 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 groups 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.

Bone marrow immunoscintigraphy in haematological patients with pancytopenia: preliminary results.

The aim of this study was to assess the clinical value of bone marrow immunoscintigraphy using the 99mTc labelled anti-NCA-95 antigranulocyte antibodies (AGAb) and of AGAb bone marrow uptake ratio (UR) in the initial diagnostic work-up of diseases with depression of the bone marrow. Twenty-four whole-body bone marrow scans were performed in 23 patients (11 women, 12 men; median age 46 years, range 17-74 years) 5 h after i.v. injection of 370 MBq of AGAb. The UR was calculated from the posterior view drawing an irregular region of interest around the sacroiliac and a background areas. The mean UR in pancytopenic patients was 2.3±1.5 (range 0.3-5.8), thus being significantly lower (P = 0.45×10−6) than the mean UR in a control group of 50 patients (mean UR 7.3±2.3; range 4.4-12.6) obtained previously. Considering patient age, there was no overlap between UR of pancytopenic patients and the respective normal ranges. The bone marrow appearance on scans seemed to be characteristic for the different haematological diseases investigated. In six patients with myelofibrosis, bone marrow scans demonstrated diffusely decreased bone marrow activity and prominent splenic uptake, possibly related to extramedullary haematopoiesis. In aplastic anaemia, highly reduced and patchy marrow uptake was observed in four patients (five scans), in one of them persisting even after blood cell counts had recovered to the near-normal range. In another two patients with aplastic anaemia, diffusely decreased bone marrow uptake was obtained. In patients with myeloid leukaemia, bone marrow patterns were almost normal probably because the target antigen is often expressed on neoplastic myeloid cells, too. Bone marrow extension was a common finding in these patients. There is an obvious differentiation between haematological patients with pancytopenia and normal subjects by means of AGAb bone marrow uptake ratio. The distinct patterns of AGAb distribution may be indicative for particular haematological diseases.

The nonspecific lymph node uptake of 18F-choline in patients with prostate cancer--a prospective observational study.

BACKGROUND The aim of this study was to observe and characterize the nonspecific ¹⁸F-choline lymph node uptake in patients with prostate cancer. MATERIAL AND METHODS In this single center, prospective observational study which was done in University Hospital Center Zagreb between December 2012 and October 2014, 69 patients (median age 71 years; range 50-92) with prostate cancer were included. Patients underwent ¹⁸F-choline PET/CT for staging or restaging of prostate cancer. The mean follow-up period was 11.5 months. Kruskal-Wallis test was used to find out if the differences between SUV values of specific and nonspecific accumulation of the tracer are statistically significant. RESULTS Nonspecific accumulation of ¹⁸F-choline in lymph nodes was found in 36 patients (52.7%). Most of these findings (n = 24) were nonspecific accumulation of the tracer in mediastinal lymph nodes. Other sites of nonspecific tracer uptake were pulmonary hila (n = 20), inguinal lymph nodes (n = 15), and axillary lymph nodes (n = 10). Mean SUV values for mediastinal lymph nodes, pulmonary hila, axillary and inguinal lymph nodes were 4.8, 4.3, 3.1 and 4.1, respectively. Mean SUV value of nonspecific sites of tracer accumulation was lower (not significantly; (p = 0.2) than tracer uptake values measured in metastases sites (bone metastases mean SUVmax value - 13.2, metastatic lymph nodes mean SUVmax value - 9.2). CONCLUSIONS ¹⁸F-choline PET/CT is a valuable and an established functional diagnostic imaging method for staging and restaging prostate cancer. However, nonspecific uptake of the tracer can often be seen in lymph nodes not related to primary disease. Patient history, clinical examination, laboratory tests and correlation with other imaging methods, must be taken into consideration when interpreting ¹⁸F-choline PET/CT findings.

The value of 18F-DOPA PET/CT in patients with medullary thyroid carcinoma and increased calcitonin values

Aim The aim of this prospective observational study was to examine the benefit of a fluorine-18-L-dihydroxyphenylalanine (18F-DOPA) PET/computed tomography (CT) scan in patients with medullary thyroid carcinoma (MTC) in terms of increased calcitonin levels. Patients and methods Twenty-eight MTC patients after initial total thyreoidectomy with increasing follow-up calcitonin levels suggestive for active disease after negative conventional imaging findings (neck ultrasound or thorax, abdomen, pelvis multislice computed tomography as standard imaging) were scanned using 18F-DOPA PET/CT from November 2012 to April 2016. The mean calcitonin level was 108.5 (range: 6.7–290) pmol/l and the mean carcinoembryonic antigen level was 15.7 (range: 1.1–221.9) &mgr;g/l. The mean follow-up period was 19.7 months. Results 18F-DOPA PET/CT was positive in 16 out of 28 (57%) patients, mostly because of metabolically active neck and mediastinal lymph nodes metastases. Previously unknown bone metastases were found in six patients. A positive scan was reported in four patients (25% of positive scans) with a very low calcitonin value of less than 49.9 pmol/l. PET/CT findings led to a change of management and therapy in 16 out of 28 patients, with surgical procedure performed in eight patients, radiotherapy in five patients, and chemotherapy in two patients. Conclusion 18F-DOPA PET/CT is a clinically useful modality in MTC whenever the calcitonin level is increased. There is a clear trend toward more positive scans with the higher calcitonin values, but patients with moderately elevated calcitonin values should also be taken into consideration for molecular imaging with 18F-DOPA PET/CT as the tumor burden in these patients is probably low, enabling further therapy to be individualized and consequently more efficient.

Bone marrow scintigraphy with 99mTc labelled monoclonal anti-NCA 90 Fab' fragment: a feasibility study and comparison of bone marrow uptake with 99mTc labelled monoclonal anti-NCA 95 antigranulocyte antibody

The aim of this retrospective study was to evaluate the usefulness of 99mTc labelled monoclonal anti-NCA 90 antigranulocyte antibody Fab′ fragment (MN3 Fab′) as a bone marrow imaging agent. One hundred and ten planar scans (88 patients) of the lumbar and sacroiliac regions as well as whole-body scans were performed after 1, 5 and 24 h. All the scans were evaluated visually and bone marrow uptake was determined semiquantitatively as count density ratio from sacroiliac-minus-background to background area. Results were compared to 50 age-matched patients with normal bone marrow scans obtained with the intact 99mTc labelled monoclonal anti-NCA 95 antigranulocyte antibody (BW 250/183) in a previous study. Seventy-three patients showed a physiological activity distribution in the central bone marrow. Ten patients showed a bone marrow extension, while in two patients central bone marrow depression was observed. Evaluation of the ribs, lower thoracic and upper lumbar spine was hampered by soft-tissue activity. Bone marrow uptake was 1.36±0.56 after 1 h, decreased thereafter and was significantly lower than that of BW 250/183 (P < 0.001). In conclusion, MN3 Fab′ cannot be recommended for bone marrow scintigraphy, because relevant parts of the haemopoietically active bone marrow are not accessible to visual evaluation. A significant role of the semiquantitative evaluation of MN3 Fab′ bone marrow uptake in patients with potential marrow depression seems unlikely.

F-18 FDG PET/CT in pulmonary artery sarcoma: clinical vignette

Pulmonary artery sarcomas (PASs) are extremely rare malignant tumors that arise from the endothelial lining of the pulmonary arteries. On CT scans PASs appear as intraluminal filling defects in the pulmonary arteries, mimicking pulmonary embolism (PE). Due to the similarities in radiographic features as well as in clinical presentation, PASs are usually misdiagnosed as pulmonary embolism. Since PASs are F-18 FDG avid, F-18 FDG PET/CT scan is a useful imaging tool for differentiating between these two conditions, as shown in this case report. We report a case of a 60-year-old woman presented with a 6-month history of chest pain, dyspnea on exertion, non-productive cough and weight loss. The initial CT pulmonary artery angiography showed extensive intraluminal mass in the pulmonary trunk and left pulmonary artery, diagnosed as massive pulmonary embolism. Since there was no clinical improvement after anticoagulant therapy, CT pulmonary angiography was repeated, and with no change observed in the intraluminal filling defect in pulmonary trunk, the possibility of tumor was raised. For further evaluation of a possible malignancy, F-18 FDG PET/CT was performed. It showed increased FDG uptake, suspicious for an aggressive tumor, in the intraluminal lesion of the pulmonary trunk and along the wall of the left pulmonary artery. There was no extrathoracic abnormality seen on PET/CT scan. Histopathological finding after complete pulmonary artery resection showed high grade undifferentiated pleomorphic sarcoma. F-18 FDG PET/CT is a useful tool for differentiating between pulmonary embolism and malignant intraluminal mass, and at the same time it enables the proper staging of the malignancy. < p > < /p >.

The Significance of Thallium-201-Chloride SPECT Myocardial Perfusion Imaging in the Management of Patients With Stable Chronic Coronary Artery Disease

Background: Patients with stable coronary artery disease (CAD) can be evaluated for myocardial viability by examining reverse redistribution of Thallium-201 (201TI) through cardiac scintigraphy. There is limited knowledge about association of a reverse redistribution with favorable cardiac outcomes. In this study, we hypothesized that higher left ventricular ejection fraction (LVEF), lower myocardial necrosis, fewer ischemic events, and less angina will be associated with reverse redistribution of 201TI imaging. Methods: Adult patients with stable CAD included in this study underwent exercise-redistribution Thallium single-photon emission computed tomography (SPECT) and were followed for one year. LVEF and regional wall motion abnormalities were evaluated with echocardiography, exercise duration by bicycle testing, and myocardial ischemia and viability by Thallium SPECT. Results: We studied 159 patients (87 men, 72 women, median age 60 years, range: 38-84) with well-developed collaterals. Those with reverse redistribution on SPECT (n = 61, 38.3%) had significantly better exercise tolerance (⩾85%; P < .001). Subjects with reverse redistribution had better LVEF (P < .001), wall motion parameters (P < .001), a lower degree of myocardial necrosis (P < .05), less angina during follow-up (P = .02), and fewer ischemic events whether treated with OMT or PCI (P < .001). Conclusions: Reverse redistribution of 201Tl on scintigraphic images is a predictor of myocardial viability. Evidence from our study suggests that optimally treated chronic CAD patients with reverse redistribution may have lower likelihood of future adverse cardiovascular events and better prognosis.

The ninth international congress of the Croatian Society of Nuclear Medicine – Rovinj, May 04–07, 2017

The Ninth International Congress of the Croatian Society of Nuclear Medicine (CSNM) was held in Rovinj, from May 04– 07, 2017. As in previous years, it was recognized as the largest nuclear medicine meeting in the region, with 230 participants from more than a dozen countries. After several successful congresses held in Opatija and 3 years ago in Šibenik, on the coastline of Dalmatia, this years’ Congress was held at the Saint Andrew Island near the old and unique city of Rovinj, on the western coast of Istria. In over 20 years since the first Congress of the Croatian Society of Nuclear Medicine held in Zagreb in 1994, there have been many scientific developments in the field of nuclear medicine and molecular imaging. This event again provided the perfect opportunity tomeet many of the internationally recognized nuclear medicine experts, to discuss and to share novel nuclear medicine achievements. Original scientific work submitted included a total of eighty-three papers, with presenters from several European countries (Austria, Croatia, Italy, Slovenia, Bosnia and Herzegovina, Germany, UK, Macedonia, France, Sweden), as well as from the USA. The program consisted of 22 invited lectures, 26 oral presentations and 35 poster presentations. The President of CSNM, Professor Dražen Huić, opened the 9th International Congress by welcoming the participants and presenting the commendations to several distinguished experts of the nuclear medicine field, prof. Michel Bourguignon, prof.Damir Dodig, prof.Onelio Geatti, and prof.Peter Lind for many years of exceptional cooperation and contribution to the development and affirmation of nuclear medicine (Figs. 1 and 2).

The Eight International Congress of the Croatian Society of Nuclear Medicine — second announcement

It is my great pleasure to invite you to the Eight International Congress of the Croatian Society of Nuclear Medicine, May 09–12, 2014, which will take place in beautiful Šibenik — a historic town, located in central Dalmatia. This is a very special occasion since 2014 we are celebrating 20th anniversary of our first congress which took place in Zagreb 1994. Our next congress will be the perfect opportunity to meet many of the world experts (about 20 invited lecturers) and to present your own achievements in the form of oral or poster presentations. We are particularly glad to announce the 10th Alpe-Adria Nuclear Medicine Symposium organized by the Austrian, Italian, Slovenian and Croatian Nuclear Medicine Societies which will be held on the same venue, on Sunday, May 11. The main topics of the symposium will be Hypothyroidism and Infection/Inflammation imaging. Simultaneously with the main program, the Annual Meeting of the Croatian Society of Nuclear Medicine Technologists will be held on May 10–12, 2014. Don’t miss the opportunity to explore Šibenik and several national parks in the neighborhood. Joining our social events you will have a chance to meet your colleagues in person and discuss with them the most interesting topics of nuclear medicine. Croatia is one of the most beautiful countries in Europe and we shall do our best to offer you a very pleasant stay and make you feel at home while being with us. The most relevant information about the congress you’ll find on our web-site http://public.carnet.hr/nuclmedzg-rebro/. The final program will be available in March 2014. We cordially invite you and look forward to seeing you in Šibenik in May 2014!