Clinical impact of margin reduction on late toxicity and short-term biochemical control for patients treated with daily on-line image guided IMRT for prostate cancer.

Gilles Crehange (1, 2) , Celine Mirjolet (1) , Melanie Gauthier (1) , Etienne Martin (1) , Gilles Truc (1) , Karine Peignaux-Casasnovas (1) , Caroline Azelie (1) , Franck Bonnetain (1) , Suzanne Naudy (1) , Philippe Maingon (1)

1 UNICANCER/CRLCC-CGFL - Centre Régional de Lutte contre le cancer Georges-François Leclerc [Dijon]
2 Le2i - Laboratoire Electronique, Informatique et Image [UMR6306]

To evaluate the impact of PTV reduction when delivering image-guided IMRT (IG-IMRT) for patients with prostate cancer. Between 2001 and 2007, 165 men were treated with daily IG-IMRT using a 3D ultrasound-based system. Median dose prescribed to the prostate was 78 Gy [74 Gy-78 Gy]. Patients were stratified regarding the CTV to the PTV margin: group A (n=87)=5mm or group B (n=78)=10mm. Late toxicity was scored using the CTC v3.0 scale. Biochemical progression-free survival (bPFS) was calculated using the Phoenix definition. Grade 2 genitourinary toxicity was 7.0% for group A and 6.6% for group B (p=1.00). Grade 2 gastrointestinal toxicity was 1.2% and 2.6% (p=0.38). With a median follow-up of 38.3 months [5.25-87.3], bPFS at 3 years was 92.5% [82.4%-96.9%] in group A and 94.3% [85.5%-97.8%] in group B (p=0.84). IG-IMRT yielded very low rates of late toxicity. Margin had impact neither on short-term bPFS nor late toxicity.

Domaines: Cancer; Imagerie médicale

Gilles Crehange, Celine Mirjolet, Melanie Gauthier, Etienne Martin, Gilles Truc, et al.. Clinical impact of margin reduction on late toxicity and short-term biochemical control for patients treated with daily on-line image guided IMRT for prostate cancer.. Radiotherapy & Oncology, 2012, 103 (2), pp.244-6. ⟨10.1016/j.radonc.2011.10.025⟩. ⟨hal-00937285⟩