Clinical results of accelerated hypofractionated radiotherapy for central-type small lung tumours.

I Fujioka,Y Hatayama,H Akimoto,M Aoki,M Sato,K Ichise,Y Takai,M Tanaka,H Kawaguchi,K Hirose,S Ono

doi:10.3747/co.24.3500

Abstract

We evaluated the efficacy and toxicity of accelerated hypofractionated radiotherapy (ahypof-rt) for central-type small lung tumours. Between November 2006 and January 2015, 40 patients with central-type small lung tumours underwent ahypof-rt delivered using 10 MV X-rays and a coplanar 3-field technique. The number of fractions ranged from 24 to 28, with a fraction size of 2.5-3 Gy. A total dose of 69-75 Gy to the isocentre of the planning target volume was administered to each patient. Cumulative survival and local control rates were calculated using the Kaplan-Meier method. The 27 men and 13 women enrolled in the study had a median age of 79 years (range: 60-87 years). The tumour stage was T1a in 9 patients, T1b in 17 patients, and T2a in 14 patients, with a median size of 26.5 cm (range: 11-49 cm). The median follow-up period was 23 months. A complete response was achieved in 3 patients (7.5%), and a partial response, in 17 patients (42.5%). The overall 2-year and 3-year local control rates were 87.3% and 81.8% respectively; the 2-year and 3-year overall survival rates were 78.9% and 66.7% respectively. Grade 3 pneumonitis occurred in 3 patients; no other severe adverse events (≥grade 3) were observed in any patient. Accelerated hypofractionated radiotherapy using a fraction size of 2.5-3 Gy was highly safe and can be a more effective treatment option than conventional radiotherapy for patients with central-type small lung tumours.

Highlights

Lung cancer is one of the most common causes of cancer death in Japan
Stereotactic body radiotherapy for medically inoperable stage i non-small-cell lung cancers and small solitary metastatic lung tumours has recently become more widespread in Japan and countries in Europe
We introduced ahypof-rt for central-type small lung tumours to improve outcomes compared with conventional rt and to reduce toxicities compared with sbrt

Summary

Introduction

The standard treatment for patients with stage i non-small-cell lung cancer is surgical, which has a 5-year overall survival (os) rate of approximately 50%−70%1–3. The number of medically inoperable stage i non-small-cell lung cancers has been increasing because of complications and older age at the time of diagnosis. Stereotactic body radiotherapy (sbrt) for medically inoperable stage i non-small-cell lung cancers and small solitary metastatic lung tumours has recently become more widespread in Japan and countries in Europe. Patients treated with conventional rt eventually develop local recurrence and distant metastasis, which lead to death, even if the initial disease is stage i. According to the literature with respect to rt using conventional fractionation, dose escalation is an important factor for local control that influences survival in patients with stage i disease[4].

Objectives

Methods

Results

Conclusion