Study on the impact of treatment planning system target volume delineation on the efficacy of iodine-125 seed therapy for non-small cell lung cancer

Abstract

This study evaluates the impact of target delineation on the dosimetric outcomes and therapeutic efficacy of iodine-125 seed implantation in the treatment of non-small cell lung cancer. A retrospective analysis was conducted on 31 patients who underwent iodine-125 seed implantation at our center. Post-operative dosimetric parameters, including target volume (Vol), minimum peripheral dose received by 90% of the target Vol (D₉₀), as well as the percentage of target Vol covered by 100% (V₁₀₀), 150% (V₁₅₀), and 200% (V₂₀₀) of the prescription dose, were recorded. Patients were divided into two groups based on treatment response: Group A (complete remission [CR]) and Group B (non-CR group). In addition, the gross target Vol (GTV) of both groups was expanded by 5 mm (clinical target volume [CTV]_5mm) and 1 cm (CTV_1mm), and the corresponding dosimetric parameters were obtained. The independent sample t-tests were used to assess differences between the two groups. All patients successfully completed surgery; among them, 15 achieved CR, 12 had partial response, three had stable disease, and one experienced disease progression. Intraoperative complications included pneumothorax (32%), with three cases (10%) requiring pleural drainage, and intrapulmonary hemorrhage (42%), including hemoptysis (13%), all of which recovered after hemostatic treatment. No other adverse reactions occurred. Statistical analysis revealed no significant difference in dosimetric parameters between the two groups immediately after surgery. However, for CTV_5mm, D₉₀ was significantly lower than its immediate post-operative value (p=0.03, <0.05), whereas the other parameters were not significantly different. Expanding the GTV by 5 mm to define the CTV improves treatment outcomes and may enhance local tumor control.

Keywords

Target delineation / Brachytherapy / Treatment efficacy / Dosimetric outcomes

Acknowledgments

None.

Funding

This study was funded by the Research Fund Project of Hebei Provincial Health and Family Planning Commission (20242265).

Conflict of interest

Hongtao Zhang is the Editorial Board Member of this journal but was not in any way involved in the editorial and peer-review process conducted for this paper, directly or indirectly. Separately, other authors declared that they have no known competing financial interests or personal relationships that could have influenced the work reported in this paper.

Author contributions

Conceptualization: Hongtao Zhang, Juan Wang

Formal analysis: Ke Xu

Investigation: Jinxin Zhao, Zezhou Liu

Methodology: Guohui Cao, Xiaoli Liu

Writing - original draft: Ke Xu

Writing - review & editing: Xiaoli Liu, Ke Xu

Ethics approval and consent to participate

This study has been approved by the Ethics Committee Application for Approval of Research Protocol, Hebei General Hospital (NO.2025-LW-0078).

Consent for publication

Not applicable.

Availability of data

The original findings presented in this study are included in the article/supplementary material. Further inquiries can be directed to the corresponding author.

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