Preoperative concurrent chemoradiotherapy (CCRT) followed by surgery has become the standard treatment for potentially resectable superior sulcus (SS) tumours. To date, intraoperative radiotherapy (IORT) for SS tumour treatment is primarily performed via brachytherapy; it achieves high local control, but has no influence on overall survival. Therefore, a novel therapy is required to increase the local control of SS tumours. The purpose of this study was to evaluate the feasibility and safety of IORT with low-energy X-rays for treating SS tumours.
Patients diagnosed with stage IIB-IIIA SS tumours with chest wall invasion and scheduled to undergo surgery were eligible for this prospective pilot study. Every patient was discussed at a lung cancer multidisciplinary team meeting. Patients with potentially resectable tumour were scheduled for neoadjuvant chemoradiotherapy followed by surgery, while those with resectable tumour were scheduled to receive surgery alone. Neoadjuvant chemotherapy consisted of two cycles of platinum-based doublet chemotherapy. Concurrent radiotherapy of 50 Gy in 25 fractions over 5 weeks was performed via intensity-modulated radiation therapy. IORT was administered to the tumour bed with close margin. The primary endpoint was acute toxicity and secondary endpoints were late spinal cord and brachial plexus toxicity.
Between August 22, 2014 and November 30, 2017, we enrolled nine patients (seven males and two females). Anaemia was the most common acute complication, with grade 3 anaemia occurring in three patients who received preoperative CCRT. Other side effects included pneumonia (1 patient), prolonged air leakage (1), and grade 1 brachial plexus injury (1). The average follow-up period was 29.4 (range; 13.3-50.4) months. All patients are alive. Distant metastasis was observed in two patients, one with contralateral lung metastasis and another with pericardial metastasis.
IORT with low-energy X-rays is a technically feasible and relatively safe treatment modality for patients with superior pulmonary sulcus tumours.