METHODS
For image guidance, three fiducial gold markers were implanted
in each patient under transurethral ultrasound guidance.
According to the risk group classification, prostate
and/or seminal vesicles and/or pelvic lymph nodes were
defined as the clinical target volume. A median of 76 Gy
(range, 74-78 Gy) was delivered to the planning target volume.
The patients were evaluated once a week during the
treatment and one month after the completion of the treatment.
Acute toxicity was scored according to the RTOG
scoring system.
RESULTS
Acute grade 2 gastrointestinal (GI) toxicity was observed in
9% of the patients, acute grade 2 genitourinary (GU) toxicity
in 65%, and grade 3 GU toxicity in 1% of the patients. No
breaks were given except for the patient with grade 3 GU toxicity.
Logistic linear regression analysis revealed maximum
rectal dose as a predisposing factor for the acute GI toxicity
and previous history of transurethral resection (TUR) for the
acute grade 2 and greater GU toxicity.
CONCLUSION
IG-IMRT is a safe method for dose escalation in localized
prostate cancer, and is tolerated well by the patients.
Keywords: Prostate cancer; image guidance; intensity modulated radiotherapy; toxicity
