How would you post-operatively manage a peripheral stage I small cell lung carcinoma s/p upfront wedge resection with an R1 microscopic positive margin along the staple line and visceral pleural invasion?

I would advise 4 cycles of chemotherapy followed by immunotherapy. It would be hard to define a “reasonable radiotherapy target” with visceral pleural involvement and surgical suture line, which is true in NSCLC as well. I would not recommend thoracic or prophylactic cranial radiotherapy.