Dr. William Oh on Reducing Prostate Cancer Risk
The detection rate depends on the tumour configuration. Detection is also limited by a considerable number of microcarcinomas that cannot be detected due to partial volume effects.
Therefore small and in part rind-like tumours can often not be visualized. Furthermore, the differentiation between Cholin Prostata changes like prostatitis, high-grade intraepithelial neoplasia HGPIN or prostatic hyperplasia is not always possible. The gold standard for diagnosing prostate cancer is histopathological examination of prostate tissue obtained by prostate needle biopsy.
Commonly used diagnostic tools in the evaluation of prostate cancer are digital rectal examination, measurement of serum levels of Cholin Prostata specific antigen PSACholin Prostata ultrasound TRUS as well as TRUS-guided biopsies 2.
Morphological imaging techniques such as TRUS, CT and MRI have demonstrated only limited accuracy for primary diagnosis of prostate cancer, recurrent disease as well as advanced disease.
Concerning diagnosis of primary prostate Cholin Prostata, CT has shown limited specificity. Furthermore the detection of lymph node metastases is limited by morphological imaging such as CT and MRI; first, small lymph node metastases cannot be visualized; second, size as only criterion might not be sufficient to detect metastatic involvement in lymph nodes.
For the detection of bone metastases, CT may be of Cholin Prostata in imaging trabecular changes caused by metastasis which appear relatively late in the course of bone metastases.
Therefore increasing the diagnostic performance in prostate cancer imaging remains a major challenge. Increased FDG Cholin Prostata and accumulation is regularly only found in dedifferentiated, aggressive and metastasized prostate cancer.
The use of choline for imaging prostate cancer is based on increased phosphorylcholine levels and an elevated phosphatidylcholine turnover in prostate cancer cells 13 - After uptake into the tumor cell through a high affinity transporter system, choline is metabolized by Cholin Prostata kinase - which is the first step of the Kennedy pathway - and is incorporated into the Cholin Prostata membrane.
Key enzymes of the choline metabolism, like choline kinase, are up-regulated in Cholin Prostata cancer cells 15 - Additionally, an increased expression of choline transporters and an elevated choline transportation rate have been described 16 - The use of [ 11 C]- and [ 18 F]-labelled choline derivates for the detection of primary prostate cancer has been examined in many studies with conflicting results, for an overview see Souvatzoglou et al.
While some studies with selected patient groups Cholin Prostata high sensitivities Cholin Prostata the detection of primary prostate cancer 21 - 23other studies reported Cholin Prostata detection rates 24 - Regarding the diagnosis of primary prostate cancer, CT cannot differentiate benign from malignant prostatic tissue; therefore the Cholin Prostata in differentiating malignant from benign prostatic lesions is limited At present, CT imaging has no Cholin Prostata role in the diagnosis of primary prostate cancer For detection, localization and definition of local extent of prostate cancer morphological and functional MRI techniques are increasingly being used.
In T2-weighted MRI, prostate cancer tissue normally presents with a decreased signal intensity compared to the high signal intensity of the normal peripheral zone This result was corroborated by Hricak et al.
Determination of the local tumor stage can be improved by using high resolution endorectal coil MRI Bloch et al. High resolution endorectal coil MRI is recommended for use as an additional imaging modality in patients with negative biopsy and suspected primary prostate cancer and patients with a medium or high Cholin Prostata of extraprostatic disease Recent studies have evaluated functional and molecular MRI techniques for primary and nodal staging of prostate cancer such Cholin Prostata diffusion weighted imaging DWI and dynamic-contrast-enhanced MRI Cholin Prostata well as magnetic resonance spectroscopy MRS.
Cholin Prostata et al. These results showed Cholin Prostata MRI and MRS had an accuracy similar to biopsy for intraprostatic localization of cancer and that they were more accurate than biopsy in the prostate Cholin Prostata Mazaheri et al. Testa et al. On contrary, Yamaguchi et al. Eschmann et al. The use of MRI with ultrasmall superparamagnetic Cholin Prostata oxide USPIO was reported to Cholin Prostata significantly better than conventional MRI in differentiating benign from malignant lymph nodes and showed a high sensitivity in Cholin Prostata of prostate cancer lymph nodes Eiber et al.
Beer et al. Based on the available literature, MRI imaging of prostate cancer is not routinely used in the diagnosis of primary prostate cancer at the Cholin Prostata time. Furthermore, MRI Cholin Prostata be useful as additional diagnostic tool in patients with multiple negative biopsies. In patients with high risk prostate cancer, an MRI or CT can be useful if the decision on the therapeutic strategy is under way.
The use of [ 18 F]fluorodeoxyglucose FDG in oncology is based on an increased glucose uptake in cancer cells by increased glucose transport through the cell membrane of malignant cells and an overexpression of the enzyme hexokinase. Liu et al. Relatively low FDG uptake has been attributed to a relatively slow metabolic rate with a lower expression of glucose transport proteins of prostate cancer cells in comparison to other cancers. There is a relationship between differentiation of prostate cancer cells and FDG uptake: low differentiated prostate cancer cells show higher FDG Cholin Prostata in comparison to higher differentiated prostate cancer cells Fig.
FDG shows renal excretion which leads Cholin Prostata activity accumulation in the ureters and the bladder potentially obscuring the target organ and the Cholin Prostata tissues like seminal vesicles, hampering the detection of prostate cancer Oyama et al. This result was confirmed by Melchior et al.
Additionally, Jadvar et al. An increase in fatty acid synthesis and an overexpression of the key enzyme fatty acid synthase have been demonstrated in prostate cancer cells In a comparative study by Oyama et Cholin Prostata.
However, [ 11 Cholin Prostata is not a cancer-specific tracer and also accumulates in normal and hyperplastic tissue. Kato et al. Wachter et al. Uptake of [ 11 C]methionine Cholin Prostata related to an increased amino acid transport and protein synthesis of cancer cells.
Nunez et al. Shiiba et al. SUV max was compared with the pathological findings. The authors divided the tumors into three groups. If the summed Gleason score of the specimens was 5 or less, they were grouped as NG no Cholin Prostata with the Gleason score. If the summed Gleason score was 6 or 7, the tumors were defined as LG low Cholin Prostata score group Cholin Prostata, and if the summed Gleason score was 8, 9 or 10, the tumors were classified as HG high Gleason score group. Therefore, [ 11 C]methionine appeared to be useful for detecting prostate cancer of both low and high Gleason score However, expression of androgen receptors is similar in prostate cancer cells compared to normal prostate cells.
Therefore, [ 18 F]FDHT might be more suitable for therapy monitoring than for diagnosing primary prostate cancer. Larson et al and Dehdashti et al. Some of the studies with a given selection of patient groups Cholin Prostata higher sensitivities for the detection of primary prostate cancer 21 - 23while other studies reported lower detection rates 24 - De Jong Cholin Prostata al.
Normal prostate and prostate cancer tissue showed Cholin Prostata SUV of 2. In 24 of 25 patients there was a focal increased choline uptake Sutinen et al. In all 14 patients visualization and detection of primary prostate cancer was possible by means of an increased choline uptake Kwee et al. Eleven of the 17 patients had bilateral positive findings in histopathology, 6 of 17 had unilateral positive findings.
Yamaguchi et al. Yoshida et al. Primary prostate cancer could be identified by means of increased choline uptake in 5 of 6 patients mean SUV of 4. Reske et al. Farsad et al. On a sextant basis histopathology was used to evaluate [ 11 C]choline uptake with respect to prostate cancer, prostatitis, benign Cholin Prostata hyperplasia and high-grade intraepithelial neoplasia HGPIN.
Scher et al. Prostate cancer prevalence in this group was Mean SUV max for prostate cancer was 4. Mean SUV max for patients without prostate carcinoma was 3. Martorana et al. Logistic regression analysis revealed that only size had an influence Cholin Prostata sensitivity. Giovacchini et al. With a SUV max cut-off of 2. Souvatzoglou et al. Therefore there is emerging evidence as discussed by Souvatzoglou et al.
SUVmean of benign prostatic lesion 2. The authors concluded that a differentiation between benign and malignant lesions is possible in most cases if imaging analysis is mainly based on qualitative criteria. The authors discussed a SUV max cut-off of 3. Therefore the authors concluded that differentiation between benign and malignant prostatic lesions was possible using [ 18 F]choline PET.
The mean SUV max for malignant findings significantly increased from 7. The mean SUV max for presumably benign lesions significantly decreased between the initial and Cholin Prostata late image 4.
The mean ratio between malignant and benign lesions increased significantly 1. Piert et al. Choline uptake correlated positively with the proliferation index Schmid et al. The mean K i -values were 0. The authors demonstrated that a high [ 11 C]choline uptake not only exists in prostate cancer but also in prostate hyperplasia meaning there is an extensive overlap in K i -values and SUV