Hypoxia-guided treatment planning for lung cancer with dose painting by numbers

Abstract

Tumor hypoxia significantly impacts the efficacy of radiotherapy. Recent advances in the methodology of dose painting by numbers (DPBN) promise to obviously improve the tumor control probability (TCP) in conventional radiotherapy for hypoxic cancer. This study firstly integrated the DPBN technique with hypoxia-guided dose distribution optimization to overcome hypoxia for lung cancers, and the DPBN plans’ efficacy and clinical suitability were assessed. 18F-FMISO PET-CT scans from 13 lung cancer patients were retrospectively employed in our study to make hypoxia-guided radiotherapy. To demonstrate clinical feasibility, TCP and normal tissue complication probability (NTCP) derived from the DPBN plans in comparison to conventional intensity modulated radiation therapy (IMRT) plans were evaluated. Furthermore, to explore the enhanced clinical acceptability, the robustness of DPBN plans against potential patient positioning errors and radiation resistance variations throughout the treatment course was assessed. The DPBN approach, employing voxelized prescription doses, led to an average increase of 24.47% in TCP, alongside a reduction of 1.83% in NTCP, compared to the conventional radiotherapy treatment plans. As for the robustness of the DPBN plans, we found that positional uncertainties confined to within 2mm and the radiosensitivity deviations within 4%. The lung NTCP showed a minimal increase when the isocenter was moved by 3mm in any direction, indicating that the DPBN plan is clinically acceptable. Thus, our study demonstrated the considerable potential of the DPBN technique as an innovative strategy to enhance the efficacy of radiotherapy for lung cancer with hypoxic regions.