This study will evaluate the safety and effectiveness of a drug called amifostine in
reducing the bowel side effects of radiation treatment for prostate cancer. Amifostine is a
'radioprotector' medicine that to protects normal tissue from radiation damage. This study
will determine whether placing amifostine in the rectum during radiation treatment for
prostate cancer can decrease common side effects of treatment, including diarrhea, painful
bowel movements, bleeding, and gas.
Patients 18 years of age or older with prostate cancer may be eligible for this study.
Candidates will be screened with a medical history and physical examination, blood tests,
bone scan if a recent one is not available, and possibly computed tomography (CT) and
magnetic resonance imaging (MRI) scans of the pelvis. They will also have a liquid retention
test, in which they are given an enema of 4 tablespoons of salt water that they must retain
for 20 minutes.
Participants will receive standard radiation therapy for prostate cancer-5 consecutive days
for 8 weeks-in the National Institutes of Health (NIH) Radiation Oncology Clinic. Amifostine
will be placed in the rectum by a mini-enema before each radiation treatment so that it
covers the lining of the rectum. To determine the side effects of the treatment, patients
will undergo a proctoscopic examination before beginning radiation therapy, two times during
therapy, and at each follow-up visit for 5 years after treatment ends. This examination
involves inserting a proctoscope (a thin flexible tube with a light at the end) into the
rectum and taking pictures.
Patients will be followed in the clinic at visits scheduled 1, 3, 6, 12, 18, 24, 36, 48, and
60 months after treatment for a physical examination and routine blood tests, proctoscopic
examination, and review of bowel symptoms.
Normal tissue tolerance of the rectum limits the dose of radiation that can be delivered to
the prostate for curative treatment of prostate cancer. Amifostine is a radioprotector, an
agent that reduces tissue damage incurred by ionizing radiation. It has been well studied
in humans and is approved for intravenous use. Rectal administration results in a
preferential accumulation of Amifostine in the rectal mucosa, and neither free parent
compound nor free active metabolite have been detected in systemic circulation. This trial
proposes to observe the rate of early and late bowel toxicity in a group of patients with
prostate cancer receiving standard high dose, 3D conformal external beam radiotherapy and
concurrent intra-rectal applications of Amifostine. Primary measures of rectal toxicity
(RTOG radiation morbidity scoring) will also be compared with self-assessment measures of
quality of life, and rectal radiation dose as assessed by dose-volume histograms.
- INCLUSION CRITERIA:
Pathologically confirmed adenocarcinoma of the prostate gland.
Age greater than or equal to 18 years.
Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
Informed consent: All patients must sign a document of informed consent indicating their
understanding of the investigational nature and risks of the study before any protocol
related studies are performed (this does not include routine laboratory tests or imaging
studies required to establish eligibility).
Other active malignancy (except for non-melanoma skin cancer).
Patient with a prior history of pelvic or prostate radiotherapy.
Patients with chronic inflammatory bowel disease.
Patients with distant metastatic disease.
Cognitively impaired patients who cannot give informed consent.
Human Immunodeficiency Virus (HIV) positivity.
Other medical conditions deemed by the principal investigator (PI) or associates to make
the patient ineligible for high dose radiotherapy.