Clinical application of high-dose, image-guided intensity-modulated radiotherapy in high-risk XXXX .

@entity1 @entity137 @entity263 @entity1600 @entity343 @entity342
PURPOSE: To report the feasibility and early @entity137 of dose-escalated image-guided IMRT to the pelvic @entity1600 ( @entity1600 ), prostate (P), and seminal vesicles (SV). METHODS AND MATERIALS: A total of 103 high-risk @entity263 @entity1 received two-phase, dose-escalated, image-guided IMRT with 3 years of @entity342 deprivation therapy. Clinical target volumes (CTVs) were delineated using computed tomography/magnetic resonance co-registration and included the prostate, portions of the SV, and the @entity1600 . Planning target volume margins ( @entity343 ) used were as follows: P (10 mm, 7 mm posteriorly), SV (10 mm), and @entity1600 (5 mm). Organs at risk (OaR) were the rectal and bladder walls, femoral heads, and large and small bowel. The IMRT was planned with an intended dose of 55.1 Gy in 29 fractions to all CTVs (Phase 1), with P+SV consecutive boost of 24.7 Gy in 13 fractions. Daily online image guidance was performed using bony landmarks and intraprostatic markers. Feasibility criteria included delivery of intended doses in 80% of @entity1 , 95% of CTV displacements incorporated within @entity343 during Phase 1, and acute @entity137 rate comparable to that of lower-dose pelvic techniques. RESULTS: A total of 91 @entity1 (88%) received the total prescription dose. All @entity1 received at least 72 Gy. In Phase 1, 63 @entity1 (61%) received the intended 55.1 Gy, whereas 87% of @entity1 received at least 50 Gy. Dose reductions were caused by small bowel and rectal wall constraints. All CTVs received the planned dose in >95% of treatment fractions. There were no Radiation Therapy Oncology Group acute @entity137 greater than Grade 3, although there were five incidences equivalent to Grade 3 within a median follow-up of 23 months. CONCLUSION: These results suggest that dose escalation to the PLN+P+SV using IMRT is feasible, with acceptable rates of acute @entity137 .
