Purpose: The current study characterized pleural changes induced by talc pleurodesis (TP), based on serial positron emission tomography/computertomography (PET/CT) with F-18 fluorodeoxyglucose (FDG). Materials and Methods: A total of 8 cancer patients who had both TP and PET/CT and no evidence of active pleural involvement after TP were retrospectively evaluated. Maximum standard uptake values, maximum Hounsfield units (HU), and thickness were followed over time. Results: The 8 patients had 25 PET/CT scans performed in an average of 22 months after TP. An increased FDG uptake was associated with an increase in pleural thickness within 5 months after TP, and both parameters showed statistical significance as compared with findings before TP. After 5 months of TP, the standard uptake value appeared to persist or increase further, and the pleural thickening stabilized. The formation of calcification was a slow process and might lag behind the changes in FDG metabolism and pleural thickness. The HU did not change significantly once pleural calcification had been formed. Conclusions: Knowledge of aforementioned pleural changes may help differentiate TP induced pleural inflammation from pleural malignancy and to avoid false-positive interpretation of FDG PET/CT exams.

Abstract. Thyroid stunning is a phenomenon of impaired thyroid tissue function after administration of a therapeutic dose of 131I subsequent to a diagnostic dose of 111- MBq (3 mCi) or greater. The impact of stunning on the clinical outcomes is still not well documented. Aim: The purpose of this study was to investigate the clinical effects of stunning. Methods: Four to six weeks after total or near-total thyroidectomy forty patients with nonmetastatic papillary or follicular carcinoma of the thyroid were evaluated. TSH level should be above 30 mU/L. They were divided prospectively into 2 groups. Group 1: 20 patients underwent 131I ablative therapy without a preliminary 131I diagnostic whole body scan. Group 2: 20 patients underwent 131I ablative therapy after preliminary 131I diagnostic whole body scan. Comparisons of the postablation outcomes were evaluated by chi (2) analysis. Successful ablation required a negative follow-up thyroid scan 6 months after ablation and also thyroglobulin level 1.5 μg/L. Results: Only 30% of patients in the scanned group had the thyroid gland ablated after a single 131I dose, compared with 85% in the non scanned group (P0.005). 30% of patients in scanned group versus 15% in non-scanned group required second therapeutic dose. 40% of patients in scanned group required third therapeutic dose. In contrast no patients received third dose in the non-scanned group. Patients in the scanned group required higher total 131I therapeutic activity (199mCi or 7.36GBq) to ablate the thyroid gland compared to those in the non- scanned group (132 mCi or 4.8 GBq). In analysis of the relation between TSH level and number of patients required single 131I dose, to achieved thyroid remnant ablation, there are 5 patients in the range from 30 to 40 mU/l, 8 patients in the range of 41 to 50 mU/l and 10 patients in the range of 51 to 61 mU/l. The difference in outcome between the scanned and the non- scanned groups demonstrates that the efficacy of 131I ablation is reduced subsequent to the use of 185 MBq (5 mCi) of 131I for diagnostic imaging. Conclusions: this study confirms that thyroid stunning after diagnostic 131I whole body scan affect the clinical outcomes of 131I ablation. We also concluded that the higher the TSH level the greater the number of ablated thyroid remnant after single 131I therapeutic dose.

Objective. To evaluate the value of quantitative SPECT bone scintigraphy in assessment of the healing process of periapical defects after filling with algae- derived hydroxapatite. Methods. Twenty patients were included in the present study. Patients were randomly allocated into two equal groups each comprised 10 subjects. In group A periapical surgery was preformed with FRIOS® Algipore® material was applied in periapical bone defects, in group B periapical surgery was preformed without FRIOS® Algipore® material was applied in periapical bone defects. SPECT bone scintigraphy was done for all patients at one month, three months and five months postoperatively. Osteoblastic activity at the defect site was compared with the activity within the skull (reference) to calculate an osteoblastic activity index (AI). Results. It was found that 11 patients (nine were in study group and two were in control group) showed three distinct phases in relation to the bone activity index. (Phase 1) demonstrates a slow rise of the AI, suggesting increased osteoblastic activity. At three months, maximal activity reached, reflected to (Phase 2). At about five months, bone activity decreased to return toward lower level than baseline values (Phase 3). However, in other nine patients (one was in study group and eight were in control group) at phase 3, bone activity decreased to return toward baseline values and not lower than them. At one month, the difference between the control and the study groups’ activity index was non-significant (P > 0.05). While at the three months, the difference between the control and the study groups’ activity index was significant (P 0.05). At the five months, the difference between the control and the study groups’ activity index was highly significant (P 0.01). Conclusion. We concluded that SPECT bone scan offers a simple, quantitative reproducible, objective, and physiologic approach to studying the osseous regeneration process that occurs after bone grafting procedure. We also concluded that algae–derived hydroxyapatite (FRIOS® Algipore®) is a good bone substitute which accelerates healing process in periapical jaw defects.