High-dose fractionated radiotherapy to 80 Gy for stage I-II medically inoperable non-small-cell lung cancer

Introduction: Management of medically inoperable non-small-cell lung cancer (NSCLC) has been historically challenging, with poor rates of local control and disease-specific survival. Nearly all published series of standard fractionation radiotherapy have utilised doses <70 Gy. The present investigation describes disease control and survival outcomes for a large series of patients prescribed high-dose radiotherapy for early-stage NSCLC.

Methods: Retrospective analysis of disease control and survival outcomes for stages I-II NSCLC patients prescribed ≥70 Gy at 1.8-2.5 Gy per fraction.

Results: Between May 1997 and August 2008, 100 primary lung tumours in 98 patients (two metachronous) were eligible for analysis. The median age was 71 years (range 49-93), and 92 patients were considered medically inoperable. Nearly all cases were clinical stage cT1N0 (51 patients) or cT2N0 (35). The median radiotherapy dose prescribed was 80.5 Gy (range 70-90). At a median follow-up of 18 months, 72 patients died (44 of/with disease) and 50 experienced recurrence. The estimated 3-year in-field control, progression-free survival, disease-specific, and overall survival rates were 50, 29, 30 and 24%, respectively. Univariate analyses demonstrated an inverse association between local control and tumour size. Medical inoperability was associated with decreased disease-specific and overall survivals. Patient age and biologically equivalent dose were also associated with overall survival.

Conclusions: Disease control and survival of fractionated radiotherapy for early-stage NSCLC remain suboptimal. Medical inoperability is associated with worse overall survival; however, local control remains a predominant pattern of failure despite 80 Gy in standard fractionation, particularly in patients with larger tumour size.