Efficacy and safety of a simplified SBRT regimen for central and peripheral lung tumours

Evaluate the safety, toxicity and efficacy of an institutional-simplified SBRT protocol with two short SBRT regimens (three or five fractions) for the treatment of lung cancer and oligometastases, according to the volume and localization of tumours.

Patients with stage I (T1 or T2) non-small cell lung cancer or lung oligometastases were treated from August 2011 to October 2015. Patients were required to be considered medically inoperable and were discussed in a multidisciplinary team.

100 patients were analysed, 59 had a peripheral location (P), and 41 a central location (C).All patients finished their SBRT course without interruptions related to acute toxicity. The most frequent acute toxicity was grade 1 asthenia, only one patient developed grade 3 toxicity (pneumonitis) and there were no grade 4 or 5 acute toxicities. Three asymptomatic radiation-induced rib fractures were identified, the 1 and 2-year rib fracture-free survival were 97% and 94%, respectively. Two-year progression-free survival and 2-year overall survival of all patients were 52% and 70%, respectively, with a median PFS and OS of 26 and 43 months. Survival free of local progression (SFLP) at 2 years was 89%. A higher PFS in primary lung cancer compared with metastatic tumours was observed, with a median of 35 months with 19 months (p = 0.01). However, no statistical difference was observed in terms of OS between both diseases.

SBRT in lung cancer with three sessions for peripheral tumours and five sessions for central tumours may be safely delivered, with low morbidity.