2023 World Conference on Lung Cancer (Posters)-EP08.02. Dosimetric Contribution of LAD Sparing Radiotherapy Plan in Patients with Postoperative Lung Cancer

EP08.02. Dosimetric Contribution of LAD Sparing Radiotherapy Plan in Patients with Postoperative Lung Cancer - PDF(Abstract)

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This study aimed to evaluate the dosimetric contribution of a left anterior descending coronary artery (LAD)-sparing radiotherapy plan in patients with postoperative lung cancer. The study used the newly defined criterion of limiting the 15Gy volume of LAD to less than 10% (LAD-V15<10%) to avoid major cardiac events. The goal was to optimize the LAD while maintaining target volume and other organ at risk (OAR) dose limitation parameters.<br /><br />The study analyzed 30 patients who received radiotherapy to the mediastinum out of a total of 54 postoperative lung cancer patients who received PORT. Previous radiotherapy plans were categorized as 3D radiotherapy (3DRT), intensity-modulated radiotherapy (IMRT), or a combination of both. The mean LAD-V15 in these patients was 38%.<br /><br />When the patients were replanned with LAD optimization, it was observed that 88% of the plans were performed with IMRT and 12% with 3DRTIMRT. The mean LAD-V15 value in the new plans was reduced to 8%. In 71% of patients, the LAD-V15 value was reduced below 10%. For the remaining 5 patients, although the LAD-V15 value could not be reduced below 10%, a significant reduction in the mean LAD-V15 value was achieved.<br /><br />In terms of cardiac dose and V30 values, the new plans showed a reduction compared to the previous plans. The mean lung V20 and mean lung dose did not show a significant difference between the previous and new plans. The mean esophageal dose was slightly reduced in the new plans.<br /><br />In conclusion, LAD-sparing radiotherapy plan optimization can effectively reduce the LAD-V15 value while maintaining target coverage and meeting standard OAR dose constraints. However, in patients who underwent radiotherapy to all lymphatic stations in the left mediastinum, significant dose reduction in LAD-V15 may not be achieved.

Asset Subtitle

Serap Akyürek

Meta Tag

Speaker Serap Akyürek

Topic Local-Regional NSCLC: Multimodality Therapy

Keywords

dosimetric contribution

left anterior descending coronary artery

LAD-sparing radiotherapy plan

postoperative lung cancer

LAD-V15<10%

major cardiac events

radiotherapy to the mediastinum

organ at risk (OAR)

3D radiotherapy (3DRT)

intensity-modulated radiotherapy (IMRT)