60.下圖為何種射源? (A)Ra-226(dumbbell) (B)I-12..-阿摩線上測驗
60.下圖為何種射源?
(A)Ra-226(dumbbell)
(B)I-125 seed(model 6711)
(C)Pd-103 seed(model 200)
(D)I-125 seed(model 6702)
3F Goal 國二下 (2019/07/09)
Iodine-125 125I has gained a wide usenfor permanent implants in radiation therapy (18,19). The advantages of this isotope overnradon and 198Au are its longnhalf-life (59.4 days), which is convenient for storage, and its low photonnenergy, which requires less shielding. However, the dosimetry of 125I is much morencomplex than the conventional interstitial sources. Three 125I seed models,ndesignated 6701, 6702, and 6711, have been manufactured,2 which are identical in size and encapsulation but differnin the active source design. The earlier model 6701 is now obsolete. Figure 15.3 sh... 查看完整內容 |
4F
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