悪性骨軟部腫瘍の治療効果判定における99mTc-MIBIシンチグラムの有用性の検討―201Tlシンチグラム，血管造影との比較

Use of 99mTc-MIBI Scintigram in the Evaluation of the Response of Chemotherapy to Malignant Bone and Soft Tissue Tumor. ; Comparison with 201Tl Scintigram and Angiogram

　悪性骨軟部腫瘍の64例に対し，^99mTc-MIBI，²⁰¹Tl，血管造影を施行し，化学療法の効果を判定した．^99mTc-MIBI，²⁰¹Tlのuptake ratioの％reductionと血管造影での評価を病理組織学的評価と比較した．血管造影像で新生血管を消失(CR)，減少(PR)，不変(NC)，増大(PD)に分類し，CRとPRを反応群とした．^99mTc-MIBIでは％reduction25％以上を反応群，²⁰¹Tlでは％reduction30％以上を反応群とした．すべての症例において切除標本を病理組織学的に評価し，壊死率90％以上を反応群とした．感度，特異度，正確度は^99mTc-MIBIで86.7％，91.2％，89.1％，²⁰¹Tlで80.0％，70.6％，75.0％，血管造影で86.7％，38.2％，60.9％であった．悪性骨軟部腫瘍に対する化学療法の効果判定において^99mTc-MIBIは最も有用な検査であると考えた．

　All 64 patients with malignant bone or soft tissue tumors who were the subjects of this study were examined by ^99mTc-MIBI scintigram, ²⁰¹Tl scintigram, and angiography to evaluate their response to chemotherapy.　The percentage reductions in uptake ratios and the changes vascularity assessed by angiography were compared with histological assessments.　Based on the angiographic findings the results were assessed as CR (complete response), PR (partial response), NC (no change), or PD (progressive disease).　On the images, ^99mTc-MIBI≧25%, ²⁰¹Tl≧30%, and CR/PR in the angiograms were assessed as responders.　All tumors were surgically resected, and the therapeutic effect was assessed by histopathological examination of the resected specimen.　The tumors of poor responders showed less than 90% necrosis, and the tumors of good responders showed 90% or more necrosis.　Sensitivity, specificity, and accuracy were 86.7%, 91.2%, and 89.1%, respectively, for ^99mTc-MIBI imaging, 80.0%, 70.6%, and 75.0%, respectively for ²⁰¹Tl imaging, and 86.7%, 38.2%, and 60.9%, respectively for angiography.　The results of this study showed that ^99mTc-MIBI scintigram could be effectively used to predict the final response of malignant bone and soft tissue tumors to chemotherapy.