CT ventilation image-guided helical Tomotherapy at sparing functional lungs for locally advanced lung cancer: analysis of dose-function metrics and the impact on pulmonary toxicity

• DOI: 10.1186/s13014-022-02189-x
• Publication Date: 2023-01-09T15:05:22Z
• Authors: Shuangshuang Li; Juan Liu; Shanbao Gao; Yicai Yin; Ling Zhang; Yongchao Han; Xishun Zhang; Yuanyuan Li; Jing Yan; Zhen Hou
• Keywords: Tomotherapy; Image registration

CT ventilation image (CTVI)-guided radiotherapy that selectively avoids irradiating highly-functional lung regions has potential to reduce pulmonary toxicity. Considering Helical TomoTherapy (HT) higher modulation capabilities, we investigated the capability and characteristic of HT at sparing functional lungs for locally advanced cancer.Pretreatment 4DCT scans were carried out 17 patients. Local volume expansion (or contraction) during inspiration is related change a given voxel used as surrogate ventilation. The maps generated from two sets images (peak-exhale peak-inhale) by deformable registration Jacobian-based algorithm. Each map was normalized percentile images. Six plans designed each patient: one anatomical plan without five incorporating which spare varying degrees high-functional defined top 10%, 20%, 30%, 40%, 50% ranges, respectively. dosimetric evaluation factors recorded regarding planning target (PTV) other organs risk (OARs), with particular attention dose delivered total lungs. An established dose-function-based normal tissue complication probability (NTCP) model estimate radiation pneumonitis (RP) scenario.Patients divided into benefit group (8 patients) non-benefit (9 based on whether RP-risk lower than plan. distance between high-ventilated region PTV, well tumor had significant differences groups (P < 0.05). For patients in group, mean value fV5, fV10, fV20, fMLD (functional V5, V10, V20, dose, respectively) significantly starting 30% With expand avoidance plans, coverage PTV not sacrificed > 0.05) but cost increased received OARs.Ventilation image-guided can range up ventilated area. spatial distribution size critical better select who could