隨著高齡化社會的來臨，各臨床專科醫師在日常診療當中，常會接觸到與日俱增的患者裝有金屬人工關節。這類金屬植入物在一般電腦斷層之影像中會造成干擾假影，而無法清楚地瞭解病灶；此外，因金屬會干擾磁場，這些病人也無法接受磁振掃描。　　
由於無法得到這些3D精密影像，因此對放射治療中相關病灶診斷與計畫的設定有很大的妨礙。在此我們利用 Tomotherapy（螺旋刀影像導引治療系統）之MVCT（百萬伏特電腦斷層掃描），不但可以減輕一般電腦斷層掃描的金屬假影，使得臨床醫師可以判別病灶所在，並將正子斷層造影之影像在放射治療計劃電腦系統上與MVCT之影像融合，可從對腫瘤細胞新陳代謝的認知，用以輔助癌症治療計劃。

In aging societies, it is common for clinicians to encounter difficulties in discerningpelvic lesions with hindrance from total hip replacement (THR) on computed tomography(CT) scans. For the patient with bilateral metallic hip prostheses, we utilizedmegavoltage computed tomography (MVCT) to overcome metallic artifacts diagnostically.The obscured lesion in conventional CT scans can be seen via MVCT providedby Tomotherapy. Serial MVCTs were merged with pretreatment positron emissiontomography (PET) images sets for target delineation during treatment planning.The application of MVCT provides insights and the feasibility of another therapeuticpathway in patients with metallic implantation.