Abstract IA23: Diagnosing prostate cancer with image fusion (MRI, PET, CT, US)

Abstract

Abstract The localization of cancer within the prostate is important for diagnosis, staging, biopsy guidance, focal therapy and active surveillance. Among the available imaging methods ultrasound offers real time monitoring but poor sensitivity, MRI offers higher sensitivity but is not real time, PET has the highest sensitivity but poor resolution and CT offers high resolution with poor sensitivity. Thus, no single imaging modality is ideal for this challenging application. This talk will focus on how we can use image fusion to combine the best aspects of each modality into a “hybrid scan” that is more than additive in its value. MRI is the best current modality for localizing prostate cancer. MRI depends on the use of multiple parameters such as T2 weighting, diffusion weighting, spectroscopy and dynamic contrast enhancement. Since each of these methods are slightly different in their acquisition parameters, these images must first be fused to create a composite multiparametric MRI. However, having localized a suspicious area on MRI, it is necessary to direct a biopsy into it. Unfortunately, doing this under MR is a tedious and imperfect process. Thus, MRI can be fused to transrectal Ultrasound for purposes of biopsy. Under ultrasound (with MR guidance), real time biopsies and even focal therapies can be performed. One disadvantage of this approach is that with focal therapies the ability to perform real time MR thermometry is lost. PET scanning has the highest sensitivity among the available modalities. To date, however, there is no ideal PET agent for localizing prostate cancer while it is still confined to the gland. However, there are a growing number of exciting PET agents that will be useful in the setting of local recurrence and advanced disease. For instance, agents such as Sodium Fluoride (F18 NaF), Dihydrotestosterone (F18-DHT), Prostate Specific Membrane Antigen (F18 DCFBC) and synthetic leucine analogs (F18-FACBC) are among the promising agents available for advanced prostate cancer. Unfortunately, PET suffers from poor spatial resolution, however fusion with CT is now commonplace. Newer scanners combine PET and MRI, thus completing the circle of possible fusions between MRI, PET, CT and Ultrasound. Such hybrid imaging promises great dividends for the management of patients with prostate cancer. Citation Format: Peter L. Choyke. Diagnosing prostate cancer with image fusion (MRI, PET, CT, US) [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr IA23.