Imaging Techniques In Prostate Cancer Research Articles

Tailored peptide nanomaterials for receptor targeted prostate cancer imaging.

We report the development of a peptide-based optical nanoprobe specifically tailored for prostate cancer imaging. The imaging probe is comprised of cyclic peptide nanotubes, formed via the aqueous co-assembly of four cyclic D,L-alternating octapeptides. The inherent properties of these cyclic building blocks have been carefully selected to enhance their efficacy in imaging applications, through the addition of a cancer targeting peptide and a fluorescent dye. Comprehensive characterization using scanning electron microscopy (FESEM) and low-voltage transmission electron microscopy (LV-TEM) confirms the formation of nanotubes through co-assembly of the cyclic peptides. The resulting nanotubes show an average diameter of 28 nm. Circular dichroism (CD) spectroscopy validates the formation of stable beta-sheet hydrogen bonding structures at both 20 and 37 °C, ensuring their suitability for biomedical applications. Evaluation of PSMA-binding specificity of the resulting peptide nanotubes is assessed using confocal fluorescence microscopy demonstrating receptor-mediated uptake in prostate cancer cells. We anticipate this strategy will provide the basis for the utilization of co-assembled systems for advancing molecular imaging techniques in prostate cancer and other cancers.

New Imaging Techniques in Prostate Cancer.

Rapid advances in diagnostic imaging have been developed in parallel with the changes in the contemporary management of prostate cancer. Increasingly, clinical management and decision making in prostate cancer are influenced by technologies such as magnetic resonance imaging-targeted prostate biopsies for men with elevated PSA, imaging for active surveillance, and nuclear medicine studies for men with advanced or recurrent prostate cancer. Furthermore, novel imaging techniques have been developed such as hyperpolarized MRI, choline and prostate-specific membrane antigen positron emission tomography that exploit features like the unique metabolism in prostate cancer tissues, as well as altered glycoprotein conformation. These technologies have allowed for the identification of tiny foci of prostate cancer in men with early biochemical recurrence, greatly surpassing the limitations of traditional morphological imaging. With promising findings, studies are ongoing to uncover the clinical application of these imaging modalities. Ultimately, several factors such as cost-effectiveness and the overall reduction in disease mortality will dictate the implementation of these imaging technologies in the future. This chapter provides an overview on new and emerging prostate imaging techniques that can be used in the diagnosis of primary cancer as well as the staging and detection of metastatic disease.

Laser Illumination Modality of Photoacoustic Imaging Technique for Prostate Cancer

Photoacoustic imaging (PAI) has recently emerged as a promising imaging technique for prostate cancer. But there was still a lot of challenge in the PAI for prostate cancer detection, such as laser illumination modality. Knowledge of absorbed light distribution in prostate tissue was essential since the distribution characteristic of absorbed light energy would influence the imaging depth and range of PAI. In order to make a comparison of different laser illumination modality of photoacoustic imaging technique for prostate cancer, optical model of human prostate was established and combined with Monte Carlo simulation method to calculate the light absorption distribution in the prostate tissue. Characteristic of light absorption distribution of transurethral and trans-rectal illumination case, and of tumor at different location was compared with each other.The relevant conclusions would be significant for optimizing the light illumination in a PAI system for prostate cancer detection.

Advances in imaging modalities in prostate cancer.

Imaging plays an important role in the clinical management of prostate cancer (PCa). Thus, much effort has gone into improving imaging modalities in PCa. This review focuses on the recent advancements in transrectal ultrasound, MRI and PET during the past year. Contrast-enhanced transrectal ultrasound with microbubbles may be useful in PCa, but needs further evaluation before more widespread use. Multiparametric MRI has emerged as a valuable tool to assist clinical management of PCa, and great progress has been made in the past year. Several radionuclides for PET/computed tomography have been tested in clinical trials; most of the studies have used radiolabeled choline. However, new PET tracers such as (18)F-1-amino-3-fluorine 18-fluorocyclobutane-1-carboxylic acid and (68)Ga-labeled prostate-specific membrane antigen ligands are demonstrating promising results. PET/MRI may further improve imaging in PCa, but this imaging modality needs to be evaluated further. Several advances in the imaging of PCa have been made during the past year. In particular, important clinical developments have been reported in multiparametric MRI, PET/computed tomography, and PET/MRI. The continuing development of imaging techniques in PCa has the potential to optimize treatment of PCa. However, the optimal imaging strategies for each of the major clinical scenarios in PCa have not yet been identified.

Dynamic Contrast-enhanced CT for Prostate Cancer: Relationship between Image Noise, Voxel Size, and Repeatability

To evaluate the relationship between image noise, voxel size, and voxel-wise repeatability of a dynamic contrast agent-enhanced (DCE) computed tomographic (CT) examination for prostate cancer. This prospective study was approved by the local research ethics committee, and all patients gave written informed consent. Twenty-nine patients (mean age, 69.1 years; range, 56-80 years) with biopsy-proved prostate cancer underwent two DCE CT examinations within 1 week prior to radiation therapy. Parameter maps of transfer constant (K(trans)), the fraction of blood plasma (v(p)), the fraction of extravascular extracellular space (v(e)), and the flux rate constant between the extravascular extracellular space and plasma (k(ep)) were calculated at 15 different image resolutions, with kernel sizes ranging from 0.002 to 2.57 cm(3). Statistical analysis to quantify the voxel-wise repeatability was performed by using a Bland-Altman analysis on all tracer kinetic model parameter maps of each patient. From this analysis, the within-voxel standard deviation (wSD) was calculated as a function of spatial resolution. A kernel size in the range of 0.1-0.3 cm(3) yields reliable information. At 0.15 cm(3), the median wSDs of K(trans), k(ep), v(p), and v(e) are 0.047 min(-1), 0.144 min(-1), 0.011, and 0.104, respectively. With increasing kernel size, these values reach stable levels of approximately 0.02 min(-1), 0.05 min(-1), 0.005, and 0.05, respectively. There is a high voxel-wise repeatability of the DCE CT imaging technique for prostate cancer for kernel sizes as small as 0.1 cm(3). With the relationship between kernel size, image noise and voxel-wise repeatability, it becomes possible to estimate for alternative DCE CT protocols (eg, those with a reduced radiation dose) at what kernel size a sufficient repeatability can be obtained.

Editorial Comment

No AccessJournal of UrologyAdult urology1 May 2007Editorial Comment Leonard G. Gomella Leonard G. GomellaLeonard G. Gomella More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2007.01.199AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "Editorial Comment." The Journal of Urology, 177(5), p. 1752 References 1 : Chemoprevention of prostate cancer in men at high risk: rationale and design of the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) trial. J Urol2004; 172: 1314. Link, Google Scholar 2 : New imaging techniques in prostate cancer. Curr Urol Rep2006; 7: 175. Google Scholar Department of Urology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania© 2007 by American Urological AssociationFiguresReferencesRelatedDetails Volume 177Issue 5May 2007Page: 1752 Advertisement Copyright & Permissions© 2007 by American Urological AssociationMetricsAuthor Information Leonard G. Gomella More articles by this author Expand All Advertisement PDF downloadLoading ...

11C-Choline Positron Emission Tomography/Computerized Tomography for Tumor Localization of Primary Prostate Cancer in Comparison With 12-Core Biopsy

(11)C-choline positron emission tomography is an innovative imaging technique for prostate cancer. We assessed the sensitivity of positron emission tomography used together with computerized tomography for intraprostatic localization of primary prostate cancer on a nodule-by-nodule basis, and compared its performance with 12-core transrectal biopsy. In 43 patients with known prostate cancer who had received positron emission tomography/computerized tomography before initial biopsy, we assessed sensitivity of positron emission tomography/computerized tomography for localization of nodules 5 mm or greater (those theoretically large enough for visualization) using radical prostatectomy histopathology as the reference standard. Comparison with transrectal ultrasound guided biopsy was based on sextant assessment of all cancer foci following sextant-by-sextant matching and reconstruction. Sensitivity/specificity of positron emission tomography/computerized tomography and magnetic resonance imaging for prediction of extraprostatic extension was also assessed. Positron emission tomography/computerized tomography showed 83% sensitivity for localization of nodules 5 mm or greater. At logistic regression analysis only nodule size appeared to influence sensitivity. At sextant assessment positron emission tomography/computerized tomography had slightly better sensitivity than transrectal ultrasound guided biopsy (66% vs 61%, p = 0.434) but was less specific (84% vs 97%, p = 0.008). For assessment of extraprostatic extension, sensitivity of PET/CT was low in comparison with magnetic resonance imaging (22% vs 63%, p <0.001). Positron emission tomography/computerized tomography has good sensitivity for intraprostatic localization of primary prostate cancer nodules 5 mm or greater. Positron emission tomography/computerized tomography and transrectal ultrasound guided biopsy show similar sensitivity for localization of any cancer focus. Positron emission tomography/computerized tomography does not seem to have any role in extraprostatic extension detection. Studies of diagnostic accuracy (as opposed to tumor localization) are needed in patients with suspected prostate cancer to see whether positron emission tomography/computerized tomography could have a role in not selected patients.

New imaging techniques in prostate cancer

New imaging techniques in prostate cancer

New imaging techniques in prostate cancer

Correct staging of prostate cancer at initial diagnosis, as well as accurate staging and tumor localization with biochemical recurrence, remains generally inaccurate with current imaging techniques. Newer modalities are being investigated to accurately identify patients with prostate cancer at different stages of disease. Identification of locally recurrent disease or distant metastasis at the time of biochemical failure after local therapy will help guide treatment options and avoid potentially toxic salvage therapies in patients who will not benefit. A review of prostate cancer imaging literature over the past 12 months was performed to identify emerging imaging modalities that may be beneficial in the management of prostate cancer. Enhanced transrectal ultrasonography modalities, including ultrasound contrast agents, color and power Doppler, and elastrography, have demonstrated incremental benefit when combined with standard gray-scale ultrasonography to accurately target and diagnose prostate cancer. Endorectal MRI, with contrast enhancement and spectroscopic imaging, shows promise in the initial staging of prostate cancer prior to local therapy. The use of positron-emission tomography scan for prostate cancer remains to be defined, but may help delineate the site of recurrence with biochemical failure after local therapy. Several new imaging modalities show promise for the evaluation of the patient with prostate cancer. Enhanced ultrasonography techniques may prove to be more accurate in diagnosing prostate cancer over standard gray-scale ultrasonography. Accumulating evidence supports the use of endorectal MRI and spectroscopy to help treatment planning with either surgical or radiotherapeutic approaches. Although intriguing, the available data for positron-emission tomography in prostate cancer remains too shallow to advocate routine use.

Improved prostate cancer imaging with SPECT/CT and MRI/MRSI

We propose a combined imaging technique for prostate cancer using /sup 111/In-ProstaScint SPECT/CT and MRI/MRSI. When used alone, either SPECT/CT or MRI/MRSI has limitations in assessing the patient undergoing clinical prostate cancer management. However, combined imaging can use MRI/MRSI to assess the prostate gland while SPECT/CT /sup 111/In-ProstaScint imaging can evaluate nearby and distant lymph nodes for metastases. The combined imaging study thereby provides complementary information useful for the cancer management. /sup 111/In-ProstaScint SPECT data are reconstructed using an iterative algorithm that includes CT-derived attenuation correction and depth-dependent collimator blurring compensation. 3D MR spectra are overlaid on the T2-weighted MR image. Image data from 3 patient studies demonstrate the potential role of combined /sup 111/In-ProstaScint SPECT/CT and MRI/MRSI imaging of prostate cancer. In the first, SPECT/CT revealed increased uptake of /sup 111/In-ProstaScint, but that occurred beyond the sensitive region of MRSI. Images from a second patient sequentially received /sup 111/In-ProstaScint SPECT/CT and MRI/MRSI in one and half months and were correlative and complementary to each other. Images from a third patient who had undergone androgen deprivation therapy show that MRI improved anatomical definition in comparison to CT, with /sup 111/In-ProstaScint indicating disease where MRSI was either equivocal or indicated atrophy. Overall, MRI/MRSI generally provided better specificity for the cancer detection within the prostate in the absence of androgen deprivation therapy, and better anatomic details of the prostate than /sup 111/In-ProstaScint SPECT/CT. Yet, /sup 111/In-ProstaScint SPECT/CT improves sensitivity for detection of distant lymph node metastases, and also is more sensitive when the patient is undergoing androgen deprivation therapy and thereby provides useful diagnostic information that complements the MRI/MRSI study alone.