薬剤関連顎骨壊死の早期発見における骨シンチグラフィおよびFDG-PETの有用性

Utility of bone scintigraphy and 18F-FDG PET/CT in early detection and risk assessment of medication-related osteonecrosis of the jaw

薬剤関連顎骨壊死（medication-related osteonecrosis of the jaw：MRONJ）は骨吸収抑制薬や血管新生阻害薬の重要な副作用であり，詳細については本特集の他稿を参照いただきたい。MRONJは進行すると難治性であるものの，早期に発見して対処できれば予後改善に結びつく。本稿では，MRONJの早期発見における骨シンチグラフィおよびFDG-PET（¹⁸F-fluorodeoxyglucose positron-emission tomography）の有用性について紹介する。

Medication-related osteonecrosis of the jaw（MRONJ）is a significant side effect of antiresorptive and antiangiogenic drugs. Since MRONJ is intractable, early detection is the best way to limit progression. Bone scintigraphy and ¹⁸F-fluorodeoxyglucose positron-emission tomography can detect minimal and subclinical changes in bones earlier than conventional radiological modalities. A differential diagnosis including MRONJ is recommended when we detect abnormally high uptakes in the jaws of patients who have bone metastases. Quantitative analysis of uptakes, such as bone scan index of the jaw（BSIJ）using neural network analysis, could differentiate MRONJ from common dental diseases and be useful for the early detection and risk assessment of MRONJ.