A Phase I Study of Image Guided Dose Escalation With Intensity Modulated Radiation Therapy (IMRT) to Histologically Confirmed Regions of Prostate Cancer

BACKGROUND:

-This study represents a progression from findings in four previous National Cancer Institute (NCI) Radiation Oncology Branch (ROB) protocols (02-C-0167A, 02-C-0207E, 03-C-0190B, 04-C-0171). In these previous works we have begun to develop techniques to obtain magnetic resonance (MR) biological images and co-register tissue in prostate cancer patients.

OBJECTIVES:

-The scientific objective of this protocol is to determine the maximum tolerated dose (MTD) of external beam radiation to regions of interest within the prostate based acute toxicity.

Secondary objectives of this study are to relate patterns in gene and protein expression to response and toxicity and to evaluate the frequency of late term toxicity.

ELIGIBILITY:

-Patients with prostate cancer without evidence of metastasis will be eligible for this study.

DESIGN:

• This phase I trial will use intensity modulated radiation therapy (IMRT) to deliver escalating doses of external beam radiation to regions of histologically confirmed prostate cancer. The study will be conducted using a standard 3-6 dose-escalation with an initial 3 patients in each dose cohort and the potential expansion of the cohort to 6 patients.
• Anatomic magnetic resonance imaging (MRI) and magnetic resonance (MR) biological images, such as magnetic resonance spectroscopy (MRS), will be obtained. Tissue will be acquired from sites of interest, with biopsy locations precisely translated (co-registered) to an MR image of reference. Tissue samples will be processed for complementary deoxyribonucleic acid (cDNA) microarray testing and stored for future analysis in the Radiation Oncology Branch, NCI. A gold seed will be left at the biopsy site as a fiducial marker to direct future radiation therapy. If necessary, additional fiducial markers will be placed for target localization during treatment.
• Once MR guided biopsies are obtained and fiducial markers placed, the patient will undergo a standard computed tomography (CT) simulation for radiation therapy treatment planning. The MR and CT images will be fused. Areas of pathologically confirmed malignancy will undergo dose escalation as described below. Areas of image abnormality that could not be biopsied or were without definite pathologic evidence of malignancy will be given intermediate doses. The remainder of the prostate gland will receive standard dose (7560 centigray (cGy)').
• The trial will accrue 18 to 36 patients with an anticipated accrual period of 2 years.