60鈷治療機光野邊界偏差不得超過()
A.1mm B.2mm C.3mm D.0.5mm E.1.5mm
60鈷治療機經(jīng)修整的半影區(qū)寬度不超過()
A.5mm B.10mm C.15mm D.20mm E.25mm
60鈷治療機等中心誤差應(yīng)不大于()
A.1mm B.2mm C.1.5mm D.2.5mm E.0.5mm