Dose-averaged linear energy transfer within the gross tumor volume of non-small-cell lung cancer affects the local control in carbon-ion radiotherapy.
retrospective_cohort · Level III
Where this comes from
- Record sourced from PubMed, PMID 39414084.
- Also identified by DOI 10.1016/j.radonc.2024.110584.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
High linear energy transfer (LET) radiation exhibits stronger tumor-killing effect. However, the correlation between LET and the therapeutic efficacy in Carbon-ion radiotherapy (CIRT) for locally advanced non-small-cell lung cancer (LA-NSCLC) is currently not clear. This study aimed to investigate the relationship between the dose-averaged LET (LET<sub>d</sub>) distribution within tumor and local recurrence for LA-NSCLC treated with CIRT. An analysis of 62 consecutive patients with LA-NSCLC who underwent CIRT from 2018 to 2022 was conducted. The LET<sub>d</sub> distribution was calculated based on their treated plans, and the correlation between local recurrence and LET<sub>d</sub>, relative biological effectiveness (RBE)-weighted doses (D<sub>RBE</sub>) and clinical factors was investigated. Receiver operating characteristic (ROC) curve, log-rank test, and Cox regression analysis were performed based on that. 16 patients were defined as local recurrence. Overall survival (OS) and local control (LC) at 24 months were 76.9 % and 73.2 %, respectively. The mean LET<sub>d</sub> in internal gross tumor volume (iGTV) in the local recurrence group was 48.7 keV/µm, significantly lower than the mean LET<sub>d</sub> of 53.2 keV/µm in the local control group (p = 0.016). No significant difference was observed in D<sub>RBE</sub> between the local recurrence and local control groups. ROC curve analysis indicated that a percentage of 88 % of volume in iGTV receiving at least 40 keV/µm (V<sub>40keV/μm</sub>) is the optimal threshold for predicting local recurrence (Area under curve (AUC) = 0.7636). The log-rank test and Cox regression analysis revealed that the LET<sub>d</sub> value covering 98 % volume of iGTV (LET<sub>d</sub>98%) was a significant risk factor for LC (p = 0.020). Our study revealed an association between LET<sub>d</sub> distribution and local recurrence in patients with LA-NSCLC. These findings suggest that lower LET<sub>d</sub> may increase the probability of local recurrence. We suggest that LET<sub>d</sub> distribution within iGTV should be routinely assessed in CIRT for lung cancer.
Medical subject headings
- Carcinoma, Non-Small-Cell Lung
- Lung Neoplasms
- Heavy Ion Radiotherapy
- Neoplasm Recurrence, Local
- Linear Energy Transfer
- Tumor Burden