TURKISH JOURNAL OF ONCOLOGY 2009 , Vol 24 , Num 3
Dosimetry and acute toxicity in prostate cancer patients treated with image-guided intensity modulated radiotherapy: preliminary results in the first 100 men
Şefik İĞDEM,1 Gül ALÇO,2 Tülay ERCAN,2 Haluk AKPINAR,3 Sedat TURKAN,2 Sait OKKAN1
1Istanbul Bilim Üniversitesi Tıp Fakültesi, Radyasyon Onkolojisi Anabilim Dalı, İstanbul
2Florence Nightingale Gayrettepe Hastanesi, Radyasyon Onkolojisi Kliniği, İstanbul
3Istanbul Bilim Üniversitesi Tıp Fakültesi, Üroloji Anabilim Dalı, İstanbul
OBJECTIVES
We aimed to analyze the dosimetric criteria and preliminary acute toxicity in the first 100 men treated with image-guided intensity modulated radiotherapy (IG-IMRT) for localized prostate cancer.

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