Imaging the Extent of Prostate Cancer
Name of the Trial
Phase I/II Pilot Study of Carbon-11 Acetate Positron Emission Tomography and 3-Tesla Magnetic Resonance Imaging in Patients With Localized Prostate Cancer Undergoing Prostatectomy (NCI-08-C-0092). See the protocol summary.
Dr. Peter Choyke, NCI Center for Cancer Research
Why This Trial Is Important
When doctors suspect a man has prostate cancer, they often use ultrasound to create images of the prostate gland and perform a series of core biopsies to collect samples of prostate tissue. Unfortunately, ultrasound does not provide very detailed images of prostate tumors, and "hit-or-miss" biopsy samples may not reveal the aggressiveness of the cancer. It is important, therefore, to develop more sensitive methods to detect and characterize prostate tumors.
Some other imaging methods, such as magnetic resonance imaging (MRI) and positron emission tomography (PET), offer some benefits in detecting and characterizing prostate cancer, but both of these methods still lack the required level of sensitivity. MRI can help determine the physical boundaries of tumor tissue, but it is not very useful in assessing which parts of the tumor are most actively growing. PET scans using radiolabeled-glucose molecules are capable of revealing areas of rapid cell growth in many tumor types; however, prostate tissue does not readily metabolize glucose, making glucose-based PET scans unreliable for prostate cancer.
In this clinical trial, researchers are testing PET scans using a different radiolabeled molecule, carbon-11 (C-11) acetate, in conjunction with subsequent MRI to see if the resulting images allow better characterization of both the physical extent and the relative level of cellular growth of prostate tumors in patients known to have prostate cancer. Following the imaging tests, the patients will undergo surgery to remove their prostates. The removed prostates will then be examined to assess the accuracy of the imaging scans.
"Detecting cancer when it is still confined to the prostate gland is the key to long survival," said Dr. Choyke. "Unfortunately, current imaging techniques have very poor sensitivity for prostate cancer. Our purpose with this study is to validate the use of both C-11 acetate PET and the latest MRI technology to detect cancer at an early stage.
"This research complements other treatment and diagnostic work at NIH, including research in robotic prostatectomy, image-guided radiotherapy, and minimally invasive radio-diagnostic procedures, making NCI a unique institution for the treatment of prostate cancer," Dr. Choyke added.