TITLE:
Image-Guided Radiotherapy Dose Escalation in Intermediate and High Risk Cancer Prostate Patients and Its Effect on Treatment Toxicity
AUTHORS:
Mohsen S. Barsoum, Azza Mohamed Nasr, Ikram Hamed Mahmoud, Salem E. Salem, Rasha A. Elawady, Shaimaa Abdelallem, Ahmed Awad
KEYWORDS:
Prostate Cancer, High-Risk, Intermediate-Risk, Fiducial Markers, Image Guided Radiotherapy, Dose Escalation, Acute Toxicity, SIB-IMRT
JOURNAL NAME:
Journal of Cancer Therapy,
Vol.8 No.6,
June
27,
2017
ABSTRACT: Purpose: To study the effect of escalating radiation dose; in intermediate and high risk prostate cancer patients; via online image-guidance on acute toxicities. Patients and Methods: thirty-eight prostate cancer patients were treated by using simultaneous integrated boost-intensity modulated radiation therapy (SIB-IMRT) with online image guided correction via kilo voltage cone beam computed tomography (KV-CBCT)/electronic portal imaging device (EPID) of trans-rectal ultrasound (TRUS)-inserted intraprostatic gold fiduciary markers. High-risk patients received a median dose of 80.5 Gy to prostate and 56 Gy to pelvic nodes in 35 fractions over 7 weeks. Intermediate-risk patients received a similar prostate dose over the same overall treatment time. Acute toxicity (bladder, rectal and bowel symptoms) was reported once weekly during the radiation course and up to 3 months from the end of the radiation course. Results: The image guided (IG)-IMRT allows escalating the radiation dose delivered to the prostate through minimizing the margin of setup error to less than 0.5 cm with subsequent sparing of nearby organs at risk. Out of thirty-eight patients, no patient developed >grade 1 acute rectal toxicity, 7.9% of patients experienced grade 3 urinary toxicity and there was no reported small intestinal toxicity. Conclusion: Escalating the radiation dose more than 80 Gy in intermediate and high risk prostate cancer patients was safe and not associated with grade 3 - 4 RTOG toxicity when guided by online verification of intra-prostatic fiducial markers.