PETの保険収載のこれまでと今後の取り組み：18F-FDG PETを中心に

Past and future efforts for PET insurance coverage：focusing on 18F-FDG PET

1980年代に世界的に院内製造の¹⁸F-fluoro-2-deoxy-D-glucose/positron emission tomography（¹⁸F-FDG PET）が使用されるようになり，我が国では1993年に¹⁸F-FDG PETが高度先進医療で承認され，普及した。最初に保険適用になったのは，1996年4月から¹⁵O-CO₂ PET（脳血流），¹⁵O-O₂ PET（酸素代謝），¹⁵O-CO PET（脳血液量）である。2002年4月には，難治性てんかん，虚血性心疾患，脳腫瘍，肺癌，乳癌，大腸癌，頭頸部癌，膵癌，悪性リンパ腫，転移性肝癌，原発不明癌，悪性黒色腫（細かい要件あり）の¹⁸F-FDG PETが保険適用になった。さらに，2006年4月からは食道癌，子宮癌，卵巣癌（細かい要件あり）が加わり，2010年4月の改定でさらに拡大となり，難治性部分てんかん（外科切除が必要とされる患者に用いる），虚血性心疾患（虚血性心疾患による心不全患者で，心筋組織のバイアビリティ診断が必要とされる患者に使用，通常の心筋血流シンチグラフィで判定困難な場合に限るもの），悪性腫瘍（早期胃癌を除く。他の検査，画像診断により病期診断，転移・再発の診断が確定できない患者に使用）が保険適用になった。2012年4月には心サルコイドーシスにおける炎症部位の診断が必要とされる患者（¹⁸F-FDG PET，¹⁸F-FDG PET/CT）が加わり，悪性リンパ腫の治療効果判定，¹³N-アンモニアによる心筋血流診断（他の検査で判断がつかない虚血性心疾患）が加わり，2013年7月からは乳腺専用PET（positron emission mammography：PEM）が従来の¹⁸F-FDG PET/CTに加えて保険適用になった。2018年4月からは血管炎（¹⁸F-FDG PET/CT，高安動脈炎などの大型血管炎において，他の検査で病変の局在または活動性の判断がつかない患者に使用）が加わっている。PET/MRIは2016年2月から悪性腫瘍（脳，頭頸部，縦隔，胸膜，乳腺，直腸，泌尿器，卵巣，子宮，骨軟部組織，造血器，悪性黒色腫）で保険適用となっている。本稿では，これらの説明と今後のPETの保険適用に向けての取り組みを概説する。

In the 1980s, the use of hospital-manufactured ¹⁸F-fluoro-2-deoxy-D-glucose/positron emission tomography（¹⁸F-FDG PET）started worldwide. In Japan, ¹⁸F-FDG PET was approved as a highly advanced medical procedure in 1993 and became widely used. In April 1996, the first products covered by insurance were ¹⁵O-CO₂ PET（cerebral blood flow）, ¹⁵O-O₂ PET（oxygen metabolism）, and ¹⁵O-CO PET（cerebral blood volume）. In April 2002, ¹⁸F-FDG PET became eligible for insurance coverage for intractable epilepsy, ischemic heart disease, brain cancer, lung cancer, breast cancer, colorectal cancer, head and neck cancer, pancreatic cancer, malignant lymphoma, metastatic liver cancer, cancer of unknown primary, and malignant melanoma（with specific criteria）. In addition, in April 2006, esophageal cancer, uterine cancer, and ovarian cancer（with specific criteria）were added. In April 2010, several advancements in its eligibility were introduced. First, it became eligible for insurance coverage for intractable partial epilepsy in patients requiring surgical resection. Second, it was eligible for patients with heart failure due to ischemic heart disease who require a diagnosis of myocardial tissue viability, but only when the condition is difficult to determine by normal myocardial blood flow scintigraphy. Lastly, it was made available for malignancy, except for early gastric cancer, in patients where other tests and imaging diagnoses cannot determine the disease stage and metastasis/recurrence. In April 2012, patients requiring diagnosis of inflammatory sites in cardiac sarcoidosis（¹⁸F-FDG PET, ¹⁸F-FDG PET/CT）were added. In addition, an assessment of its treatment efficacy for malignant lymphoma and diagnosis of myocardial blood flow using ¹³N-ammonia（when an assessment cannot be made using other tests）were added. In July 2013, PET for mammary glands（PET/PEM）was added to the existing¹⁸F-FDG PET/CT and became eligible for insurance coverage. In April 2018, ¹⁸F-FDG PET/CT was introduced as an alternative method for determining the location of lesions or lesion activity in large vasculitis, such as Takayasu arteritis, for patients who cannot use other tests. In February 2016, PET/MRI became eligible for insurance coverage for the following malignancies：brain, head and neck, mediastinum, pleura, breast, rectum, urinary tract, ovary, uterus, bone and soft tissue, hematopoietic organ, and malignant melanoma. This article outlines these explanations and future efforts for PET insurance coverage.