Background: This retrospective study analyzed factors influencing hypothyroidism development after radioactive iodine therapy for Graves' disease.
Patients and methods: Three hundred and three patients with Graves' disease treated with radioactive iodine (RAI) from 2013 to 2022 at two Egyptian hospitals were included. Data collected included demographics, lab values, thyroid imaging, RAI doses, and outcomes. Patients were followed for ≥1 year to assess hypothyroidism onset.
Results: At the end of 1 year, around 79.5% of the individuals developed hypothyroidism while 12.5% continued to experience hyperthyroidism. The onset of hypothyroidism occurred earlier in those with thyroid volume (≤75.5 cm 3 ), lower thyroid weight (≤84.7 g), thyroid uptake (≤18.8%), and higher RAI dose/volume (≥0.1022 mCi/ml) ( P < 0.001). Additionally, there was a correlation between anti-thyroid peroxidase (anti-TPO) antibodies and faster development of hypothyroidism compared to those who were negative for antibodies (2.9 vs 8.9 months, P = 0.001). When considering factors in analysis it was found that anti-TPO antibodies were the only independent predictor, for developing hypothyroidism (hazard risk 30.47, P < 0.001). Additionally, thyroid volume and uptake independently predicted successful treatment outcomes ( P < 0.05).
Conclusion: Positive anti-TPO antibodies strongly predict hypothyroidism risk after RAI therapy for Graves' disease. Smaller thyroid size, lower uptake, and higher RAI dose/volume correlate with earlier hypothyroidism onset but are less significant predictors than anti-TPO status. Findings can guide RAI therapy personalization to optimize outcomes.
: Breast cancer has the highest incidence among all female patients with different cancer types. It is a lethal disease which threaten women's health. There are many prognostic and predictive factors that implicated in breast cancer. The expression of Ki-67 is strongly associated with cancer proliferation and is a known indicator of breast cancer prognosis and outcome. Ki-67 expression levels are also useful to inform treatment decision making in some cases. As a result, measurement of Ki-67 is routinely done during pathological tumor evaluation.
In radiotherapy treatment couches, rigid carbon fiber couch inserts reduce set-up errors caused by couch sagging. These inserts have been described in several studies as radio-translucent with negligible radiation field attenuation. The majority of these tests were carried out with the radiation field normally incident on the center of the couch, and there appears to be no evidence in the literature of the effect of the thickest region (edge of the couch) on the attenuation and dose distribution during external beam radiotherapy. In this study, we evaluated and improved the calculated dose attenuation for the under-couch fields to reduce the skin surface dose. Using the difference between the measured and calculated attenuation doses obtained using the ion chamber and the “TPS” treatment planning system; an algorithm that identifies the influence of couch attenuation on patient dose verification. According to our results, the attenuation is affected by the gantry angle, where the maximum attenuation was at 180°, the angle at which the couch attenuates the 6 MV photon beam by 9.3 % for 10×10 cm2 field sizes, while the attenuation at 1600 and 1400 was less where the lowest attenuation recorded at 1400 at which angle the couch attenuated the 6 MV photon beam by 2.4. It would appear, therefore, that Connexion central opening couch with posterior beams results in significant decreases in the dose delivered to the target. The measured data were compared to the calculated values from the Monaco Treatment Planning System, and computed using the Monte Carlo (MC) and Collapsed Cone (CC) algorithms. The most minor agreement was observed at an angle of 1800 between the calculated and the measured attenuation for the 5 x 5 cm² field size with 6 MV and 10 MV photon beam energy where the difference was 5.3 % and 4 % for the MC and CC algorithm, respectively. Excellent agreement was observed at an angle of 160 between calculated and measured attenuation with the field sizes of 10 x 10 cm² for 6 MV, in which the difference (lose dose) was ±1.5 %.
