radionuclidetherapy放射性治疗ppt课件.ppt

Contraindication 1. Patients who are in pregnancy and lactation. 2. Patients whose leucocyte count are below 3.0×109/L or with severe hepatic and renal insufficiency. Selection of Therapeutic Dose The treatment for functioning metastatic thyroid carcinoma must balance the need for a cytocidal tumor dose against side effects produced in healthy tissue by such a dose. Inadequate treatment could simply reduce the iodine concentration ability of metastases, reducing effectiveness of future therapy, without leading to tumor sterilization. When the radiation dose to metastatic lesions exceeded 8 000 rads, 98% of lesions responded to treatment while none responded to doses less than 3 500 rads. It has excellent results using an empirically administered activity of 150 to 175 mCi for cervical node metastase, 175 to 200 mCi for pulmonary metastases, and 200 mCi for skeletal metastatic disease. Selection of Therapeutic Dose This radioisotope is often supplied as a solution of sodium iodide and, especially with a low pH, is volatile. Therefore the manipulation of 131I should be performed in a fume hood with the exhaust fan. All iodine vials must be handled behind lead glass shielding with long handle tongs, and then kept in lead containers. 2.3 Radiation Safety with Iodine-131 Hospitalized patients remain in a single room and are monitored one to two times daily for radiation burden, Saving urine for counting purpose can lead to contaminating spills. and this is not a recommended safety technique. No restrictions are required when the average exposure rate measures 2 mR/hr at any distance. 2.3 Radiation Safety with Iodine-131 1. Cytopenia； 2. Radiation pneumonitis； 3. Acute and/or chronic sialadenitis； 4. Gastrointestinal radiation is not uncommon, begins about 4 to 12 hours after 131I administration, has a prevalence of 50% to 70%,and generally resolved by 36 hours, probably related to the intestinal concentration of 131I. 2.4 Side Effect of 131I Therapy Autonomously fu