Central lung re-irradiation achieved 80% one-year local control with limited severe toxicity

KEY POINTS

• The single-centre retrospective study included 30 patients re-irradiated between 2014 and 2024 for recurrent central lung cancer, including 24 NSCLC and 6 SCLC cases. Forty percent already had metastatic disease when the recurrence requiring re-irradiation was diagnosed.
• Median interval between RT courses was 12 months and median re-irradiation dose was 49.5 Gy EQD2₁₀. Median cumulative EQD2 from all courses was approximately 113.6 Gy, reflecting substantial prior exposure.
• Despite the high-risk central location, estimated 1-year local control was 80.1% and 1-year overall survival was 61%. Median overall survival was 24 months.
• Progression-free survival was much poorer at 19.3% at one year, largely because subsequent progression was predominantly distant: 59.1% of progressing patients developed distant metastases, compared with 18.2% local and 13.6% locoregional progression.
• Acute grade 2 esophagitis occurred in 5/30 patients (16.6%). All patients whose cumulative esophageal V60 exceeded 50% developed clinically relevant esophagitis, although toxicity also occurred below this threshold and the cohort is too small to define a constraint.
• Severe toxicity was uncommon during the available follow-up: one patient developed grade 3 esophageal stenosis, and one developed grade 2 radiation pneumonitis. Several patients exceeded contemporary cumulative OAR recommendations, including esophageal, airway and spinal-cord limits.
• Interpretation is limited by the 30-patient retrospective cohort, mixed NSCLC/SCLC population, heterogeneous prior therapy, short median follow-up and uncertainty in deformable registration and cumulative dose reconstruction. Late toxicities may therefore be underestimated.

CLINICAL TAKEAWAY

SOURCE

Strahlentherapie und Onkologie