On-levothyroxine measurement of thyroglobulin is not a reliable test for the follow-up of patients at high risk for remnant/recurrent differentiated thyroid carcinoma

Wstęp: Obecnie najszerzej akceptowanym narzędziem używanym w badaniach kontrolnych u chorych ze zróżnicowanym rakiem tarczycy jest pomiar osoczowego stężenia tyreoglobuliny (Tg). Nierzadko zdarza się, iż pomiary stężenia Tg odbywają się, gdy chory jednocześnie przyjmuje preparaty hormonów tarczycowych. Celem niniejszego badania była ocena przydatności pomiaru osoczowego stężenia Tg w trakcie stosowania hormonów tarczycy w wykrywaniu choroby resztkowej/nawrotowej lub obecności przerzutów u chorych z wysokim ryzykiem wznowy zróżnicowanego raka tarczycy. Materiały i metody: Retrospektywnej analizie poddano dokumentację medyczną 26 pacjentów obciążonych dużym ryzykiem wystąpienia zróżnicowanego raka tarczycy. Porównano wartości pomiarów osoczowego stężenia Tg odpowiednio w trakcie stosowania hormonów tarczycy oraz po ich odstawieniu. U wszystkich badanych wykluczono obecność przeciwciał przeciwko Tg. Przyjmując pomiary stężenia Tg w okresie odstawienia hormonów tarczycy jako "złoty standard", przeanalizowano (ustalając czułość, specyficzność oraz dodatnią i ujemną wartoœæ predylekcyjną) wyniki oznaczeń stężenia Tg podczas przyjmowania hormonów tarczycy pod kątem diagnostyki resztkowej/nawrotowej choroby. Wyniki: Średnie osoczowe stężenie Tg w warunkach stosowania terapii supresyjnej za pomocą podawanych egzogennych hormonów tarczycy wynosiło 16,5 ng/ml, natomiast po zaprzestaniu stosowania tyroksyny - 95,0 ng/ml (wartość p = 0,001). U 6 chorych (23%) przyjmujących hormony tarczycy stężenie Tg nie potwierdzało wznowy procesu nowotworowego. Przy założeniu, że pomiary stężenia Tg w okresie odstawienia hormonalnych preparatów tarczycy stanowią "złoty standard", czułość, specyficzność dodatnia i ujemna wartość predylekcyjna wynosiły odpowiednio: 72,7%, 100%, 100% i 40%. Wnioski: Monitorowanie stężenia Tg w trakcie terapii tyroksyną nie jest wiarygodną metodą w wykrywaniu wznowy choroby u chorych na zróżnicowanego raka tarczycy.Introduction: At present the most widely accepted tool for follow-up management of differentiated thyroid cancer (DTC) patients is serum thyroglobulin (Tg) measurement. It is not uncommon for the serum Tg level to be measured while the patient is taking thyroid hormones (on-treatment Tg measurement). The purpose of the study was to evaluate the accuracy of on-treatment measurement of serum Tg in detecting remnant/recurrent or metastatic disease in high-risk DTC patients. Material and methods: We retrospectively analysed the medical records of 26 high-risk DTC patients and compared the on-treatment and off-treatment Tg levels of these patients. All patients were anti-Tg negative. Using off-treatment measurement of Tg as the gold standard, the results of on-treatment measurement of Tg in the diagnosis of remnant/recurrent disease were analysed for sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV). Results: The median serum Tg level under thyroid hormone suppressive therapy (on-treatment Tg) was 16.5 ng/ml and after withdrawal of thyroid hormone suppressive therapy (off-treatment Tg) was 95.0 ng/ml (P value = 0.001). In 6 patients (23%) the on-treatment Tg level missed the recurrence of the disease. Regarding the off-treatment Tg as the gold standard, the sensitivity, specificity, PPV and NPV of the on-treatment Tg measurement were 72.7%, 100%, 100%, and 40% respectively. Conclusion: Normal serum Tg level without TSH-stimulation (on-treatment) is not diagnostically reliable in the follow-up of DTC patients with a high probability of residual/recurrent or metastatic disease

Frequency and severity of myocardial perfusion abnormalities using Tc-99m MIBI SPECT in cardiac syndrome X

BACKGROUND: Cardiac syndrome X is defined by a typical angina pectoris with normal or near normal (stenosis <40%) coronary angiogram with or without electrocardiogram (ECG) change or atypical angina pectoris with normal or near normal coronary angiogram plus a positive none-invasive test (exercise tolerance test or myocardial perfusion scan) with or without ECG change. Studies with myocardial perfusion imaging on this syndrome have indicated some abnormal perfusion scan. We evaluated the role of myocardial perfusion imaging (MPI) and also the severity and extent of perfusion abnormality using Tc-99m MIBI Single Photon Emission Computed Tomography (SPECT) in these patients. METHODS: The study group consisted of 36 patients with cardiac syndrome X. The semiquantitative perfusion analysis was performed using exercise Tc-99m MIBI SPECT. The MPI results were analyzed by the number, location and severity of perfusion defects. RESULTS: Abnormal perfusion defects were detected in 13 (36.10%) cases, while the remaining 23 (63.90%) had normal cardiac imaging. Five of 13 (38.4%) abnormal studies showed multiple perfusion defects. The defects were localized in the apex in 3, apical segments in 4, midventricular segments in 12 and basal segments in 6 cases. Fourteen (56%) of all abnormal segments revealed mild, 7(28%) moderate and 4 (16%) severe reduction of tracer uptake. No fixed defects were identified. The vessel territories were approximately the same in all subjects. The Exercise treadmill test (ETT) was positive in 25(69%) and negative in 11(30%) patients. There was no consistent pattern as related to the extent of MPI defects or exercise test results. CONCLUSION: Our study suggests that multiple perfusion abnormalities with different levels of severity are common in cardiac syndrome X, with more than 30 % of these patients having at least one abnormal perfusion segment. Our findings suggest that in these patients microvascular angina is probably more common than is generally believed

Evaluation of the Possible Utilization of 68Ga-DOTATOC in Diagnosis of Adenocarcinoma Breast Cancer

Objective(s): Studies have indicated advantageous properties of [DOTA-DPhe1 , Tyr3 ] octreotide (DOTATOC) in tumor models and labeling with gallium. Breast cancer is the second leading cause of cancer mortality in women, and most of these cancers are often an adenocarcinoma. Due to the importance of target to non-target ratios in the efficacy of diagnosis, the pharmacokinetic of 68Ga-DOTATOC in an adenocarcinoma breast cancer animal model was studied in this research, and the optimized time for imaging was determined. Methods: 68Ga was obtained from 68Ge/68Ga generator. The complex was prepared at optimized conditions. Radiochemical purity of the complex was checked using both HPLC and ITLC methods. Biodistribution of the complex was studied in BALB/c mice bearing adenocarcinoma breast cancer. Also, PET/CT imaging was performed up to 120 min post injection. Results: The complex was produced with radiochemical purity of greater than %98 and specific activity of about 40 GBq/mM at optimized conditions. Biodistribution of the complex was studied in BALB/c mice bearing adenocarcinoma breast cancer indicated fast blood clearance and significant uptake in the tumor. Significant tumor:blood and tumor:muscle uptake ratios were observed even at early times postinjection. PET/CT images were also confirmed the considerable accumulation of the tracer in the tumor. Conclusion: Generally, the results proved the possible application of the radiolabelled complex for the detection of the adenocarcinoma breast cancer and according to the pharmacokenitic data, the suitable time for imaging was determined as at least 30 min after injection

Investigation of the effects of tumor size and type of radionuclide on tumor curability in targeted radiotherapy

Background: Targeted radiotherapy is one of the important methods of radiotherapy that involves the use of beta-emitting radionuclides to deliver a dose of radiation to tumor cells. An important feature of this method is the tumor size and the finite range of beta particles emitted as a result of radionuclide disintegration those have significant effects for the curability of tumors. Material and Methods: Monte Carlo simulations and mathematical models have been used to investigate the relationship of curability to tumors size for tumors treated with targeted 131I and 90Y. The model assumed that radionuclides are distributed uniformly throughout tumors. Results: The results show that there is an optimal tumor size for cure. For any given cumulated activity, cure probability is greatest for tumors whose diameter is close to the optimum value. There is a maximum value of curability that occurs at a diameter of approximately 3.5 mm for 131I. For 90Y maximum curability occurs at a tumor diameter of approximately 3.5 cm. Tumors smaller than the optimal size are less vulnerable to irradiation from radionuclides because a significant proportion of the disintegration energy escapes and is deposited outside the tumor volume. Tumors larger than the optimal size are less curable because of greater clonogenic cell number. Conclusion: With single radionuclide targeted radiotherapy, there is an optimal tumor size for tumor cure. It is suggested that single agent targeted radiotherapy should not be used for treatment of disseminated disease when multiple tumors of differing size may be present. The use of several radionuclides concurrently would be more effective than reliance on single radionuclide. This approach of using combination of radionuclides with complementary properties could hopefully prepare new measures and improve the efficiency of tumor therapy

Radiosynthesis and biodistribution studies of [62Zn/62Cu]-plerixafor complex as a novel in vivo PET generator for chemokine receptor imaging

In order to develop a possible C-X-C chemokine receptor type 4 (CXCR4) imaging agent for oncological scintigraphy, [62Zn]labeled 1,1'-[1,4-phenylenebis(methylene)]bis-1,4,8,11-tetraazacyclotetradecane ([62Zn]-AMD3100) was prepared using in-house made [62Zn]ZnCl2 and AMD-3100 for 1h at 50 °C (radiochemical purity: >97 % ITLC, >96 % HPLC, specific activity: 20-22 GBq/mmol) in acetate buffer. The complex showed highly hydrophilic properties (log P = -1.114). Stability of the complex was checked in presence of human serum (37 °C) and in final formulation for 1 day. The biodistribution of the labeled compound in vital organs of wild-type Sprague-Dawdley rats were determined and compared with that of free Zn2+ cation up to 6h. Co-incidence imaging of the complex was consistent with the distribution data up to 3h. The complex can be a possible in vivo generator compound for PET imaging in CXCR4 positive tumors

Neuroendocrine tumors treatment with I-131 Metaiodobenzylguanidine (MIBG)

Background: I-131 Metaiodobenzylguanidine (MIBG) is a radiopharmaceutical which is proved effective in treatment of tumors with neuroendocrine origin, especially the neuroectodermal (sympathoadrenal) type, including pheochromocytoma, paraganglioma and neuroblastoma. It is also of some value in other neuroendocrine tumors (mainly carcinoid and medullary carcinoma of thyroid). Methods: The method employed in this research was a systematic bibliographic review, in which only valid studies or the clinically detailed enough open-labeled studies using validated scales were used. Results: I-131 MIBG is the best nonsurgical method for treatment of pheochromocytoma. It not only increases survival, but also significantly improves patients&rsquo; symptoms (75-90%). Although the efficacy of this method for refractory or relapsing neuroblastoma has been 30%, adding other treatment modalities increases the impact of this treatment. For other neuroendocrine tumors including carcinoid tumor and medullary carcinoma of thyroid, MIBG therapy has been effective in reducing patients&rsquo; symptoms. The most important complication of this method is myelosuppression which needs follow-up and if necessary relevant treatment. Conclusion: I-131 MIBG has an important role in treatment of chromafin tumors. For pheochromocytoma and neuroblastoma it is the best nonsurgical treatment. It is effective in neuroblastoma especially if it is used in conjunction with other treatment modalities. I-131 MIBG can also diminish symptoms of carcinoid tumor and medullary thyroid carcinoma efficiently

Successful application of technetium-99m-labeled octreotide acetate scintigraphy in the detection of ectopic adrenocorticotropin-producing bronchial carcinoid lung tumor: a case report

Abstract Introduction The diagnostic efficacy of somatostatin receptor scintigraphy labeling with 111 indium in the localization of tumors has been assessed in a limited number of patients with contradictory outcomes. Here, we describe the case of a patient with an ectopic adrenocorticotropic hormone-producing bronchial carcinoid tumor diagnosed preoperatively using technetium-99m-labeled octreotide acetate scintigraphy. Case presentation A 29-year-old Asian man presented to our hospital with the typical clinical features of Cushing's syndrome, which he had had for a duration of 18 months. The results of a biochemical evaluation revealed he had adrenocorticotropic hormone-dependent Cushing's syndrome. The results of a spiral abdominal computed tomography scan showed he had bilateral adrenal hypertrophy. A magnetic resonance image of the patient's brain showed he had a normal hypophysis. Whole body technetium-99m-labeled octreotide acetate scintigraphy was performed to check for the presence of an ectopic adrenocorticotropic hormone-producing tumor. The scan results showed a small focal increase in uptake in the lower lobe of our patient's right lung, just above his diaphragm. A spiral chest computed tomography scan also revealed a small non-specific lesion in the same region. A transthoracic biopsy was then performed. Pathological evaluation confirmed the diagnosis of a carcinoid tumor, of the adrenocorticotropic hormone-producing type. After surgical removal, the patient's symptoms resolved and significant clinical improvement was achieved. Conclusions This case report shows that technetium-99m-labeled octreotide acetate scintigraphy can effectively detect an ectopic adrenocorticotropic hormone-producing bronchial carcinoid.</p