Initial clinical experience with stereotactic lung radiotherapy, based on a biological model-driven prescription...

Area of Science:

• Oncology
• Radiotherapy
• Medical Physics

Background:

• Stereotactic body radiotherapy (SBRT) is a key treatment for early-stage non-small cell lung cancer (NSCLC).
• Accurate dose selection is crucial for balancing treatment efficacy and toxicity.
• Patient-specific biological dose selection models aim to optimize SBRT fractionation.

Purpose of the Study:

• To evaluate the initial clinical outcomes of SBRT for early-stage NSCLC using a patient-specific nomogram-based biological dose selection (NBDS) model.
• To assess the safety and efficacy of SBRT guided by the NBDS model in terms of local control, survival, and toxicity.

Main Methods:

• 23 patients with stage IA/B NSCLC received SBRT with a prescription isodose volume/residual lung volume ratio of 2-3%.
• Dose fractionation schemes were determined by the NBDS model to predict low rates of pneumonitis.
• Kaplan-Meier analysis was used to evaluate survival and local control; toxicity and response rates were also analyzed.

Main Results:

• Median follow-up was 43.2 months.
• 80% major response rate observed in 20 evaluable lesions.
• 3-year survival rates were 60% (overall), 79% (cause-specific), and 55% (disease-free).
• 3-year local control was 89%.
• Grade 2 or higher pulmonary toxicity occurred in 15-27% of patients, with grade 3 incidence at 4-10%.

Conclusions:

• SBRT utilizing an NBDS model achieved local control and survival rates comparable to higher-dose regimens.
• Observed pulmonary toxicity rates were within the model's predicted parameters.
• Further follow-up is required to confirm the long-term validity of the NBDS model.