RESUMO
BACKGROUND: Uterine artery embolization (UAE) is a minimally invasive procedure performed under fluoroscopy for the treatment of uterine fibroids and accompanied by radiation exposure. OBJECTIVES: To compare ovarian radiation doses during uterine artery embolization (UAE) in patients using conventional digital subtraction angiography (DSA) with those using digital flat-panel technology. PATIENTS AND METHODS: Thirty women who were candidates for UAE were randomly enrolled for one of the two angiographic systems. Ovarian doses were calculated according to in-vitro phantom study results using entrance and exit doses and were compared between the two groups. RESULTS: The mean right entrance dose was 1586±1221 mGy in the conventional and 522.3±400.1 mGy in the flat panel group (P=0.005). These figures were 1470±1170 mGy and 456±396 mGy, respectively for the left side (P=0.006). The mean right exit dose was 18.8±12.3 for the conventional and 9.4±6.4 mGy for the flat panel group (P=0.013). These figures were 16.7±11.3 and 10.2±7.2 mGy, respectively for the left side (P=0.06). The mean right ovarian dose was 139.9±92 in the conventional and 23.6±16.2 mGy in the flat panel group (P<0.0001). These figures were 101.7±77.6 and 24.6±16.9 mGy, respectively for the left side (P=0.002). CONCLUSION: Flat panel system can significantly reduce the ovarian radiation dose during UAE compared with conventional DSA.
RESUMO
Total Body Irradiation (TBI) is a form of radiotherapy used for patients prior to bone marrow or stem cell transplant to destroy any undetectable cancer cells. The dosimetry characteristics of a (60)Co unit for TBI were studied and a simple method for the calculation of the prescribed dose for TBI is presented. Dose homogeneity was verified in a human phantom. Dose measurements were made in water phantom (30 × 30 × 30 cm(3)), using farmer ionization chamber (0.6 cc, TM30010, PTW) and a parallel plate ionization chamber (TM23343, PTW). Point dose measurements for AP/PA irradiation were measured in a human phantom using silicon diodes (T60010L, PTW). The lung dose was measured with an ionization chamber (0.3 cc, TM31013). The validity of the proposed algorithm was checked at TBI distance using the human phantom. The accuracy of the proposed algorithm was within 3.5%. The dose delivered to the mid-lobe of the lung was 14.14 Gy and it has been reduced to 8.16 Gy by applying the proper shield. Dose homogeneity was within ±7% for all measured points. The results indicate that a good agreement between the total prescribed and calculated midplane doses can be achieved using this method. Therefore, it could be possible to use calculated data for TBI treatments.