title: Hypofractionated Prostate Radiotherapy with or without Conventionally Fractionated Nodal Irradiation: Clinical Toxicity Observations and Retrospective Daily Dosimetry.
abstract: Purpose. To evaluate toxicity associated with the addition of elective nodal irradiation (ENI) to a hypofractionated regimen for the treatment of prostate cancer. Methods and Materials. Fifty-seven patients received pelvic image-guided IMRT to 50.4 Gy in 28 fractions with a hypofractionated simultaneous boost to the prostate to 70 Gy. Thirty-one patients received prostate-only treatment to 70 Gy in 28 fractions. Results. Median followup was 41.1 months. Early grade ≥2 urinary toxicity rates were 49% (28 of 57) for patients receiving ENI and 58% (18 of 31) for those not (P = 0.61). Early grade ≥2 rectal toxicity rates were 40% (23 of 57) and 23% (7 of 31), respectively (P = 0.09). The addition of ENI resulted in a 21% actuarial rate of late grade ≥2 rectal toxicity at 4 years, compared to 0% for patients treated to the prostate only (P = 0.02). Retrospective daily dosimetry of patients experiencing late rectal toxicity revealed an average increase of 2.67% of the rectal volume receiving 70 Gy compared to the original plan. Conclusions. The addition of ENI resulted in an increased risk of late rectal toxicity. Grade ≥2 late rectal toxicity was associated with worse daily rectal dosimetry compared to the treatment plan.
authors.affiliation: Department of Radiation Oncology, Hazelrig-Salter Radiation Oncology Center, University of Alabama at Birmingham, 1700 6th Avenue South Birmingham, Birmingham, AL 35249, USA.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: McDonald
authors.forename: Justin M
authors.initials: JM
authors.lastname: Bishop
authors.forename: Rojymon
authors.initials: R
authors.lastname: Jacob
authors.forename: Michael C
authors.initials: MC
authors.lastname: Dobelbower
authors.forename: Robert Y
authors.initials: RY
authors.lastname: Kim
authors.forename: Eddy S
authors.initials: ES
authors.lastname: Yang
authors.forename: Heather
authors.initials: H
authors.lastname: Smith
authors.forename: Xingen
authors.initials: X
authors.lastname: Wu
authors.forename: John B
authors.initials: JB
authors.lastname: Fiveash