ABSTRACT
Purpose: The study is intended to perform an end-to-end test of the entire intraoperative process using cadaver heads. A simulation of tumor removal was performed, followed by irradiation of the bed and measurement of absorbed doses with radiochromic films. Materials and Methods: Low-energy X-ray intraoperative radiotherapy (IORT) was used for irradiation. A computed tomography study was performed at each site and the absorbed doses calculated by the treatment planning system, as well as absorbed doses with radiochromic films, were studied. Results: The absorbed doses in the organs at risk (OAR) were evaluated in each case, obtaining maximum doses within the tolerance limits. The absorbed doses in the target were verified and the deviations were <1%. Conclusions: These tests demonstrated that this comprehensive procedure is a reproducible quality assurance tool which allows continuous assessment of the dosimetric and geometric accuracy of clinical brain IORT treatments. Furthermore, the absorbed doses measured in both target and OAR are optimal for these treatments.
ABSTRACT
OBJECTIVES: The aim of this study was to analyze the operator radiation exposure (ORE) and the image quality in a coronary angiography (CA) of the standard left lateral view (LLV) and compare it with an alternative right lateral view (RLV). BACKGROUND: Interventional cardiologists are exposed to high doses of scatter radiation, especially in angulated projections. METHODS: We prospectively included consecutive patients who underwent diagnostic CA. A standard +90° LLV and an alternative RLV (-90°) were done in each patient with the same protocol. The operator effective dose rate (mSv/h) was determined for each projection with digital dosimeters located in the collar, waist and knee. The image quality of both the LLV and RLV was analyzed and compared to a standard projection. RESULTS: 116 patients were enrolled; left coronary artery (LCA) was assessed in 52 patients and right coronary artery (RCA) in 64 patients. The ORE was significantly lower with the RLV compared to the conventional LLV with a maximum ORE reduction of 91.5% in the operator waist (LLV: 6.84 mSv h-1 versus RLV: 0.58 mSv h-1, p < 0.001). No significant differences in image quality were observed for the RCA in both projections. For the LCA, a slight loss of quality was observed with the RLV. CONCLUSIONS: -90° RLV is associated with a significant decrease in ORE compared to the conventional +90° LLV without losing image resolution for the RCA and resulting in a slight quality loss for the LCA evaluation. The RLV should be the first choice for RCA evaluation. For the LCA, the RLV loss of resolution should be balanced with the benefit of minimizing ORE, mainly in cases with long fluoroscopy times, such as complex percutaneous coronary interventional procedures.
