Caineng Cao1, Pengfei Yang2, Yuanfan Xu3, Tianye Niu2, Qiaoying Hu1, Xiaozhong Chen4. 1. Department of Radiation Oncology, Zhejiang Cancer Hospital, Zhejiang Key Laboratory of Radiation Oncology, Hangzhou, Zhejiang, China. 2. Department of Radiation Oncology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang, China. 3. Hangzhou Universal Medical Imagine Diagnostion Center, Hangzhou, Zhejiang, China. 4. Department of Radiation Oncology, Zhejiang Cancer Hospital, Zhejiang Key Laboratory of Radiation Oncology, Hangzhou, Zhejiang, China. Electronic address: chenxiaozhong2016@163.com.
Abstract
OBJECTIVE: The aim of this pilot study was to explore the integrated positron emission tomography and magnetic resonance imaging scanner (PET/MR) for biological characterization of nasopharyngeal carcinoma (NPC) and potential therapeutic applications of dose painting (DP). PATIENTS AND METHODS: Twenty-one NPC patients with PET/MR were included in this study. Overlap of tumor volumes was analyzed on T2-weighted images (volume of interest, VOIT2), diffusion-weighted magnetic resonance imaging (VOIDWI) and 18F-fluorodeoxyglucose positron emission tomography (VOIPET). The overlap percentages of low-metabolic sub-region (cluster 1) and high-metabolic sub-region (cluster 2) in VOIPET and VOIDWI were analyzed by cluster analysis. RESULTS: Both the VOIDWI and VOIPET were encompassed in the VOIT2, respectively 99.6% and 97.5%. The median tumor overlap was 94.4% (VOIDWI within VOIPET). The median overlap of cluster 2 in VOIPET and VOIDWI was 43.61% (27.67-52.66%) and 21.86%(10.47-40.89%), respectively. The median overlap of cluster 1 in VOIPET and VOIDWI was 48.03% (23.91-63.15%) and 24.40% (7.44-51.44%), respectively. Separation between clusters appeared to be defined by a SUV value. CONCLUSION: For NPC, the VOIs of DWI and FDG PET were not overlapped completely and the volume defined by cluster-analysis might be meaningful for DP.
OBJECTIVE: The aim of this pilot study was to explore the integrated positron emission tomography and magnetic resonance imaging scanner (PET/MR) for biological characterization of nasopharyngeal carcinoma (NPC) and potential therapeutic applications of dose painting (DP). PATIENTS AND METHODS: Twenty-one NPC patients with PET/MR were included in this study. Overlap of tumor volumes was analyzed on T2-weighted images (volume of interest, VOIT2), diffusion-weighted magnetic resonance imaging (VOIDWI) and 18F-fluorodeoxyglucose positron emission tomography (VOIPET). The overlap percentages of low-metabolic sub-region (cluster 1) and high-metabolic sub-region (cluster 2) in VOIPET and VOIDWI were analyzed by cluster analysis. RESULTS: Both the VOIDWI and VOIPET were encompassed in the VOIT2, respectively 99.6% and 97.5%. The median tumor overlap was 94.4% (VOIDWI within VOIPET). The median overlap of cluster 2 in VOIPET and VOIDWI was 43.61% (27.67-52.66%) and 21.86%(10.47-40.89%), respectively. The median overlap of cluster 1 in VOIPET and VOIDWI was 48.03% (23.91-63.15%) and 24.40% (7.44-51.44%), respectively. Separation between clusters appeared to be defined by a SUV value. CONCLUSION: For NPC, the VOIs of DWI and FDG PET were not overlapped completely and the volume defined by cluster-analysis might be meaningful for DP.