A. Reig

EP-1221: Accelerated hypofractionated three-dimensional conformal radiation therapy (AHRT) for NSCLC

Results: The main result was the reduction in primary and nodal volumes due to better definition of lung mass and nearby lung Collapse , the latter could be easily defined in 14 cases on the DW-MRI vs. 7 cases only by CT scans (P=0.016). Median GTV total (sum of 1ry and nodal GTV), on MRI Diffusion compared to that on the CT scan was 354 and 386 cm3 respectively (P= 0.009). In 15 cases, a mean decrease in the GTV total of 34% ±56% (median, 9%; range, 0.232.5%) by using DW-MRI. only in three other cases a mean increase in the GTV total of 12.7% ±14.9% (median, 9.7%; range, 0.4221%). was found. The median PTVs on the CT scans vs. the MRI Diffusion were 1623 (range, 493–2965 cm3) & 1419 (range, 542–3158 cm3) respectively which was statistically non significant (P= 0.391).