Real-time tumor tracking radiotherapy for patients with hypoxic primary lung cancer

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K10378
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Radiation science
• Research Institution: Hokkaido University
• Principal Investigator: INOUE TETSUYA 北海道大学, 医学研究院, 非常勤講師 (10431363)
• Co-Investigator(Kenkyū-buntansha): 榊原 純 (小西純) 北海道大学, 大学病院, 講師 (50374278) ; 志賀 哲 北海道大学, 医学研究院, 准教授 (80374495)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 原発性肺癌 / 体幹部定位放射線治療 / 低酸素

Outline of Final Research Achievements

Hypoxic regions in tumors are known to be radio-resistant. Hypoxic imaging became possible by positron emission tomography (PET) using 18F-fluoromisonidazole (FMISO). Here we sought to determine whether FMISO-PET/CT can be used to predict the outcome for stage I non-small cell lung cancer (NSCLC) patients treated by stereotactic body radiotherapy (SBRT). From September 2013 to August 2017, 29 patients at Hokkaido university hospital with histopathologically confirmed stage I NSCLC were enrolled. FMISO-PET/CT was performed before SBRT for all patients. 18F-fluorodeoxy glucose (FDG)-PET/CT was also performed before SBRT. Four patients had a relapse. They were both FDG- and FMISO-positive. The proportion of recurrence in FMISO was 4/12 in positive and 0/17 in negative (p=0.01), whereas that in FDG was 4/19 in positive and 0/10 in negative (p=0.12). FMISO-PET/CT can be considered useful for predicting the outcome for stage I NSCLC patients treated by SBRT rather than FDG-PET/CT.

Free Research Field

放射線腫瘍学

Academic Significance and Societal Importance of the Research Achievements

早期の非小細胞肺癌への体幹部定位放射線治療は手術に匹敵する有効な治療法として確立されてきたが、少なからず再発症例も経験し、治療成績改善の余地がある。本研究により低酸素細胞を有する原発性肺癌においては、低酸素細胞を有しないものよりも再発リスクが高い可能性が示された。早期原発性肺癌に対して、再発リスクの高い症例群が選別可能となったが、それらの群に対してより適切な治療法を模索していくことが今後の課題である。