Biologically effective dose (BED) value lower than 120 Gy improve outcomes in lung SBRT

Area of Science:

• Radiation Oncology
• Medical Physics
• Oncology

Background:

• Stereotactic Body Radiation Therapy (SBRT) is established for early-stage non-small cell lung cancer (NSCLC) in non-surgical candidates.
• A biologically effective dose (BED) of ≥100 Gy is recommended, but optimal fractionation remains unclear.
• This study evaluates outcomes based on prescribed doses in patients treated with lung SBRT.

Purpose of the Study:

• To analyze patient outcomes treated with lung SBRT at our institution.
• To evaluate the relationship between prescribed radiation dose and patient survival.
• To determine optimal dose fractionation for lung SBRT.

Main Methods:

• Retrospective analysis of 109 patients with early-stage NSCLC treated with lung SBRT.
• Stratification of patients into high (BED > 120 Gy) and low (BED < 120 Gy) dose groups for comparison.
• Evaluation of local control and survival rates in relation to radiation dose received.

Main Results:

• A correlation between higher total radiation doses (mean 54.7 Gy ± 4.8) and increased mortality was observed (p < 0.003).
• Patients receiving BED > 120 Gy showed significantly increased mortality compared to those receiving BED < 120 Gy (p = 0.021).
• A mean dose per fraction of 12.6 Gy/f was identified as a protective factor against mortality.

Conclusions:

• Lower mean total doses (< 54 Gy) and BED < 120 Gy appear optimal for lung SBRT.
• These findings suggest that current high-dose SBRT may lead to increased mortality.
• Further prospective studies are required to confirm these results and establish optimal dose fractionation based on tumor characteristics.