TITLE:
Evaluation of Acute Toxicity and Dosimetric Parameters in High Risk Prostate Cancer Patients Treated by High Radiation Doses
AUTHORS:
Mohamed A. Daoud, Yasser M. Saleh, Mohamed Elsherbini, Mostafa Al Etreby
KEYWORDS:
Radiation Therapy, Dose Escalation, Cancer Prostate, Androgen Deprivation Therapy
JOURNAL NAME:
Journal of Cancer Therapy,
Vol.10 No.8,
August
21,
2019
ABSTRACT: For high risk prostate cancer, the treatment volumes and even dose levels
are still a controversial issue. The aim of this study is to evaluate the
dosemetric parameters and acute toxicity of dose-escalated whole pelvis (WP)
Intensity Modulated Radiation Therapy (IMRT) and volumetric modulated arc
therapy (VMAT) prostate boost following neoadjuvant and concomitant with
androgen deprivation therapy in high-risk prostate cancer patients. This
analysis included 73 high-risk prostate cancer patients treated with WP-IMRT
followed by boost to the prostate by VMAT to total dose of 80 Gy; between January 2014 and October 2016. Androgen deprivation therapy
(ADT) was given for all patients before and during radiation therapy. Drawing
the dose volume histograms (DVHs) was done for planning target volumes (PTVs),
including Prostate PTV & nodal PTV, and organs at risk including rectum,
bladder, femoral heads, and bowel bag for the plans. Acute radiation toxicities
were reported during the radiation course and the following 3 months. The DVH
analysis showed good coverage of PTVs and organs at risk doses were acceptable.
No recorded acute Grade ≥ 3 toxicity. Acute grade 1 toxicity for
Gastrointestinal (GI) and Genitourinary (GU) were 65% and 35% respectively,
while Grade 2 toxicity was 30% for both. The Proctitis and frequency were the
commonest acute toxicity and were maximal during the 5th week of radiation
therapy. Dose escalation in two phases utilizing Simultaneous integrated boost
(SIB) combined with ADT in high risk prostate cancer patient is feasible and
associated with acceptable acute GI and GU toxicity.