Early pulmonary toxicity following lung stereotactic body radiation therapy delivered in consecutive daily fractions

Background and purpose: Identify the incidence of early pulmonary toxicity in a cohort of patients treated with lung stereotactic body radiation therapy (SBRT) on consecutive treatment days. Material and methods: A total of 88 lesions in 84 patients were treated with SBRT in consecutive daily fractions (Fx) for medically inoperable non-small cell lung cancer or metastasis. The incidence of pneumonitis was evaluated and graded according to the NCI CTCAE v3.0. Results: With a median follow-up of 15.8 months (range 2.5-28.6), the median age at SBRT was 71.8 years (range 23.8-87.8). 47 lesions were centrally located and 41 were peripheral. Most central lesions were treated with 48 Gy in 4 Fx, and most peripheral lesions with 54 Gy in 3 Fx. The incidence of grade ≥2 pneumonitis was 12.5% in all patients treated, and 14.3% among the subset of patients treated with 54 Gy in 3 Fx. A total of two grade 3 toxicities were seen as one grade 5 toxicity in a patient treated for recurrence after pneumonectomy. Conclusions: Treating both central and peripheral lung lesions with SBRT in consecutive daily fractions in this cohort was well tolerated and did not cause excessive early pulmonary toxicity.