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The aim of this study was to study the technical factors affecting the reading of TLD (LiF:Mg:Ti) for radiation dosimetry. The method adapted was an exposure of LiF:Mg:Ti crystal with γ-ray with the following filters (Hp 0.07 and Hp 10), before and after usage of filter Hp (0.07), annealing, cooling by nitrogen flux and crystal morphology by scanning electron microscope. The collected data analyzed by EXCELL software showed that: TLD average count/second (C/s) with filter Hp (10) was greater than that obtained with filter Hp (0.07) with an amount of 1191 c/s (19%). Also the analysis showed that: the average C/s without filter Hp (0.07) was greater than that with filter by an amount of 994.5 C/s (16.4%), and there was proportional linear relationship; as the applied dose increased the TLD C/s increased significantly (R 2 = 0.9) based on the equations: y = 885.1x − 286.5 and y = 860.5x + 856.8 for filtered and without filtered beam respectively, where x refers to applied dose in mGy and y refers to C/s. Also the average C/s without nitrogen flux (cooling) was greater than with nitrogen count with an amount of 52.4 C/s (11%). The annealing (without filter) causes a reduction in dose by 82.2 μGy (19.2%), and in case of annealing with filter, the dose reduced by 66.7 μGy (21.9%) relative to annealing without filter. The morphology of TLD crystal shown by scanning electron microscope SEM was a darkening surface after irradiation.

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Consequences of breast, head and neck cancers (HNC) radiotherapy are common among developing country patients; hence the aim of this work was to assess the impact of HNC (nasopharyngeal, laryngeal and hypopharyngeal and parotid) radiotherapy in thyroid and lungs functions. The data (tumor dose, dose histogram) has been retrieved from treatment planning system (TPS) and the thyroid hormones (T 3 , T 4 and TSH) level pre/post radiotherapy was measured by radioimmunoassay (RIA) technique. Ages (18 -55 for HNC and 20 -65 for breast cancer) derived from PACS and respiratory rate (RR) assessed by counting the number of breathing/minutes. The analyzed data using Excel showed that: the impact of HNC without parotid and supraclavicular irradiation was significant (P = 0.00) reduction on T 3 & T 4 , and increasing TSH hormones relative to applied tumor dose. The average doses (2.8, 30, 32, 33 and 20.5 Gy) received by thyroid gland from irradiation of parotid, larynx, breast, hypopharynx and nasopharynx respectively reduced T 4 /T 3 hormones to 125.9/0.8, 109/0.6, 67.8/0.4, 33.9/0.3 and 105.8/0.7 respectively and increased TSH to 4.5, 6.3, 8.1, 11.5 and 0.65 mU/l respectively. The RR increased significantly (P = 0.05) from 19.1 ± 3.6 to 22.1 ± 3.4 in average due to tangential fields irradiation of breast. Conclusion addressing that: conventional radiotherapy for HNC & breast induce a significant reduction in thyroid hormones and increment of RR.

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