Radiologically Occult Lung Cancer Curatively Treated with High-Dose Rate Endobronchial Brachytherapy

Abstract
Most patients diagnosed with early-stage non-small cell lung cancer (NSCLC) can be easily cured with surgery or stereotactic body radiotherapy (SBRT). Modalities such as photodynamic therapy, cryotherapy, or laser therapy only offer temporary palliation. A 79-year-old gentleman with early-stage NSCLC who underwent a left lower lobe lobectomy in 2009 presented to us again in 2010 with hemoptysis. A friable ~5 cm tumor along the bifurcation of anterior and the posterior segment of the right upper lobe was noted on bronchoscopic examination, and biopsy confirmed this to be squamous cell carcinoma. Because of his previous surgery, the patient was not a candidate for another surgery. SBRT was not possible as the lesion could not be seen on radiologic imaging. The patient was, therefore, treated with curative intent high-dose rate endobronchial brachytherapy (HDR-EBBT) in 4 weekly sessions of 7 Gy per fraction delivered at a depth of 8 mm, covering ~5 cm tumor plus 1 cm margin proximally and distally. He tolerated the treatment well without any acute or late side effects and was followed every 3 months thereafter with bronchoscopy examinations for 6 months and subsequently with computerized tomography (CT) imaging. In July 2018, the patient started having episodes of hemoptysis and evaluation leads to diagnosis of a third primary lung cancer, which was successfully treated with SBRT with image-guided radiotherapy using a five-fraction regimen. The patient’s most recent CT from July 2019 showed no evidence of disease. We conclude that in patients with early-stage NSCLC, when surgery or SBRT is not feasible due to radiologic occult nature, HDR-EBBT can yield excellent long-term outcome.