Pauliina Wright1,2, Marius Røthe Arnesen3, Per-Ivar Lønne4, Sami Suilamo1,2, Antti Silvoniemi5, Einar Dale6, Heikki Minn7, Eirik Malinen4,8. 1. Department of Oncology and Radiotherapy, Turku University Hospital, Turku, Finland. 2. Department of Medical Physics, Turku University Hospital, Turku, Finland. 3. Icon Cancer Centre Toowoomba, Toowoomba, Australia. 4. Department of Medical Physics, Oslo University Hospital, Oslo, Norway. 5. Department of Otorhinolaryngology-Head and Neck Surgery, Turku University Hospital, Turku PET Centre, University of Turku, Turku, Finland. 6. Department of Oncology, Oslo University Hospital, Oslo, Norway. 7. Department of Oncology and Radiotherapy, Turku University Hospital, Turku PET Centre, University of Turku, Turku, Finland. 8. Department of Physics, University of Oslo, Oslo, Norway.
Abstract
BACKGROUND: Hypoxia dose painting is a radiotherapy technique to increase the dose to hypoxic regions of the tumour. Still, the clinical effect relies on the reproducibility of the hypoxic region shown in the medical image. 18F-EF5 is a hypoxia tracer for positron emission tomography (PET), and this study investigated the repeatability of 18F-EF5-based dose painting by numbers (DPBN) in head and neck cancer (HNC). MATERIALS AND METHODS: Eight HNC patients undergoing two 18F-EF5-PET/CT sessions (A and B) before radiotherapy were included. A linear conversion of PET signal intensity to radiotherapy dose prescription was employed and DPBN treatment plans were created using the image basis acquired at each PET/CT session. Also, plan A was recalculated on the image basis for session B. Voxel-by-voxel Pearson's correlation and quality factor were calculated to assess the DPBN plan quality and repeatability. RESULTS: The mean (SD) correlation coefficient between DPBN prescription and plan was 0.92 (0.02) and 0.93 (0.02) for sessions A and B, respectively, with corresponding quality factors of 0.02 (0.002) and 0.02 (0.003), respectively. The mean correlation between dose prescriptions at day A and B was 0.72 (0.13), and 0.77 (0.12) for the corresponding plans. A mean correlation of 0.80 (0.08) was found between plan A, recalculated on image basis B, and plan B. CONCLUSION: Hypoxia DPBN planning based on 18F-EF5-PET/CT showed high repeatability. This illustrates that 18F-EF5-PET provides a robust target for dose painting.
BACKGROUND: Hypoxia dose painting is a radiotherapy technique to increase the dose to hypoxic regions of the tumour. Still, the clinical effect relies on the reproducibility of the hypoxic region shown in the medical image. 18F-EF5 is a hypoxia tracer for positron emission tomography (PET), and this study investigated the repeatability of 18F-EF5-based dose painting by numbers (DPBN) in head and neck cancer (HNC). MATERIALS AND METHODS: Eight HNC patients undergoing two 18F-EF5-PET/CT sessions (A and B) before radiotherapy were included. A linear conversion of PET signal intensity to radiotherapy dose prescription was employed and DPBN treatment plans were created using the image basis acquired at each PET/CT session. Also, plan A was recalculated on the image basis for session B. Voxel-by-voxel Pearson's correlation and quality factor were calculated to assess the DPBN plan quality and repeatability. RESULTS: The mean (SD) correlation coefficient between DPBN prescription and plan was 0.92 (0.02) and 0.93 (0.02) for sessions A and B, respectively, with corresponding quality factors of 0.02 (0.002) and 0.02 (0.003), respectively. The mean correlation between dose prescriptions at day A and B was 0.72 (0.13), and 0.77 (0.12) for the corresponding plans. A mean correlation of 0.80 (0.08) was found between plan A, recalculated on image basis B, and plan B. CONCLUSION: Hypoxia DPBN planning based on 18F-EF5-PET/CT showed high repeatability. This illustrates that 18F-EF5-PET provides a robust target for dose painting.
Authors: Arian Pérez Nario; Jenilee Woodfield; Sofia Nascimento Dos Santos; Cody Bergman; Melinda Wuest; Yasniel Babí Araújo; André Luis Lapolli; Frederick G West; Frank Wuest; Emerson Soares Bernardes Journal: EJNMMI Radiopharm Chem Date: 2022-06-13