LAUSR

chemotherapy. With a median follow up of 73.8 months the local progression free survival at 3 years was 90.9% after 24Gy and 74.6% after 4Gy; the corresponding rates at 5 years are 89.9% after 24Gy and 74.4% after 4Gy; at the median follow up of 73.8 months the rates are 89.3% and 68% (Hazard ratio (HR): 3.46 (95% CI: 2.25 – 5.33, p<0.001)see figure below. There remains no difference in overall survival (HR: 1.03 (0.74 – 1.43, p = 0.86). Median time to local progression has not been reached but for patients who had local progression these occurred at a median time of 19.3 months (range: 1.3 – 65.0) for sites treated with 24 Gy and 11.7 months (range: 0.9 – 88.3) for sites treated with 4Gy. In the subgroup treated with curative intent there were 5/119 relapses after 24Gy and 29/129 after 4Gy: HR: 5.80 (2.25 – 14.99) p<0.0001. Conclusions: Whilst 4 Gy in 2 fractions can be effective in the palliative setting, it is significantly inferior to 24 Gy in 12 fractions. This difference is maintained with long term follow up and is greatest in patients treated with radical intent. 24Gy in 12 fractions should remain the schedule of choice for curative radiation therapy in follicular or marginal zone lymphoma.