Radiation-Associated Lung Adenosquamous Carcinoma Diagnosed by Robotic-Assisted Bronchoscopy With Cone-Beam CT Guidance and Treated With Robotic Superior Segmentectomy: A Case Report.

Prior thoracic or chest-wall radiotherapy carries a small but meaningful risk of second primary malignancy after a prolonged latency period. Chronic post-radiation changes may also complicate the evaluation of new pulmonary lesions, particularly when fibrosis, traction bronchiectasis, and architectural distortion are present. Advances in robotic-assisted bronchoscopy combined with radial endobronchial ultrasound (rEBUS), augmented fluoroscopy, and cone-beam computed tomography (CBCT) may facilitate localization and tissue diagnosis of suspicious peripheral pulmonary lesions in this setting. We report the case of an 82-year-old woman with a remote smoking history and recurrent myxofibrosarcoma of the left upper back. At Year 0, she underwent surgical resection followed by adjuvant radiotherapy to 60 Gy in 30 fractions. At Year 10, she developed a high-grade local recurrence that was managed with radical re-excision followed by electron re-irradiation to an additional 60 Gy in 30 fractions. Whole-body PET/CT performed during evaluation of the recurrence showed no evidence of distant metastatic disease. She did not receive systemic therapy for her myxofibrosarcoma. During surveillance following re-irradiation, imaging identified an enlarging spiculated left lower lobe lesion with associated traction bronchiectasis adjacent to post-treatment changes in the posterior thoracic region. PET/CT demonstrated increased fluorodeoxyglucose (FDG) uptake within the lesion, with a maximum standardized uptake value (SUVmax) of 2.9, increasing suspicion for malignancy, although inflammatory processes may also demonstrate FDG uptake. Robotic-assisted bronchoscopy with rEBUS, CBCT, and augmented fluoroscopic guidance established the diagnosis of primary lung adenocarcinoma. Following multidisciplinary evaluation, the patient underwent robotic-assisted superior segmentectomy with systematic lymph node dissection and additional margin resection. Final pathology demonstrated a 2.2 cm well-differentiated adenosquamous carcinoma confined to the lung parenchyma, with negative sampled lymph nodes and a negative final margin. Surveillance imaging approximately seven months after resection demonstrated no new pulmonary nodules or masses. The temporal and anatomic relationship of the lesion to prior chest-wall radiotherapy raised consideration of a radiation-associated malignancy; however, causality cannot be established from a single case. Available 2024 boost-plan dosimetry demonstrated limited average pulmonary exposure, although cumulative dose at the exact lesion site was not available. This case illustrates the successful use of robotic bronchoscopy, rEBUS, CBCT, and augmented fluoroscopy for lesion localization and tissue diagnosis in complex post-treatment thoracic anatomy without establishing superiority over alternative diagnostic approaches.