Stage 1 EGFR lung adenocarcinoma treated with radiotherapy

What happened, in summary

A 71-year-old man was being evaluated after a thoracic spinal cord infarction that caused leg weakness, wheelchair dependence, and bladder-rectal dysfunction when CT incidentally found a band-like lesion in the left upper lung near the pleura. He was an ex-smoker and was taking clopidogrel. The lesion measured 37 x 7 mm, was not visible on conventional chest radiography, and initially looked possibly inflammatory, so it was monitored with serial CT scans. After 2.5 years, it had enlarged slightly to 38 x 10 mm. Blood tests, tumor markers, and infectious studies were unremarkable, but PET showed FDG uptake, raising concern for malignancy. Because the lesion was near the pleura and the patient was on antiplatelet therapy, the team used virtual bronchoscopy navigation with endobronchial ultrasound using a guide sheath. Although fluoroscopy could not detect the lesion, ultrasound localized it, allowing brushings and 4 biopsies without major bleeding or pneumothorax. Histology showed TTF-1-positive adenocarcinoma cells in fibrotic tissue. A high-sensitivity compact gene panel on cytology material found an EGFR exon 19 deletion, with no detected ERBB2, KRAS, BRAF, ALK, ROS1, RET, or MET alterations. He was diagnosed with Stage IB cT2aN0M0 lung adenocarcinoma. Because of his fragile condition, he received radical radiotherapy rather than surgery or chemotherapy: 66 Gy in 33 fractions to the primary lesion, including hilar and mediastinal lymph nodes. Grade 2 radiation esophagitis improved with oral sodium alginate, and treatment was completed. At 5 months, the lesion was stable, with no recurrence or radiation pneumonitis. He was disappointed by the lung-cancer diagnosis after the spinal-cord event but reassured that it had not metastasized, and he continued rehabilitation.