Lymph Node Staging In Prostate Cancer Research Articles

Functional and Targeted Lymph Node Imaging in Prostate Cancer: Current Status and Future Challenges.

Patients with prostate cancer who have regional lymph node (LN) metastases face an increased risk of death from disease and are therefore treated aggressively. Surgical LN dissection is the established method of staging regional nodes; however, this invasive technique carries substantial morbidities and a noninvasive imaging method is needed to reduce or eliminate the need for extended pelvic LN dissections (ePLND). Conventional computed tomography and magnetic resonance (MR) imaging have proven insensitive and nonspecific because both use nodal size criteria, which is notoriously inaccurate. Novel imaging techniques such as functional MR imaging by using diffusion-weighted MR imaging, MR lymphography with iron oxide particles, and targeted positron emission tomography imaging are currently under development and appear to improve LN staging of prostate cancer. Although progress is being made in staging nodes with imaging, it has not reached the point of replacing ePLND. In this review, the strengths and limitations of these new functional and targeted LN imaging techniques for prostate cancer are discussed. © RSNA, 2017.

Simplified intraoperative sentinel-node detection performed by the urologist accurately determines lymph-node stage in prostate cancer

Objective. The reference standard for lymph-node staging in prostate cancer is currently an extended pelvic lymph-node dissection (ePLND), which detects most, but not all, regional lymph-node metastases. As an alternative to ePLND, sentinel-node dissection with preoperative isotope injection and imaging has been reported. The objective was to determine whether intraoperative sentinel-node detection with a simplified protocol can accurately determine lymph-node stage in prostate cancer patients. Materials and methods. Patients with biopsy-verified high-risk prostate cancer with tumour stage T2–3 were included in the study. All patients underwent both ePLND and sentinel-node detection. 99mTc-marked nanocolloid was injected peritumourally by the operating urologist after induction of anaesthesia just before surgery. Sentinel nodes were detected both in vivo and ex vivo intraoperatively using a gamma probe. Sentinel nodes and metastases and their locations were recorded. Sensitivity and specificity were calculated. Results. At least one sentinel node was detected in 72 (87%) of the 83 patients. In 13 (18%) of these 72 patients sentinel nodes were detected outside the ePLND template. In six of these 13 patients, the Sentinel nodes from outside the template contained metastases, which proved to be the only metastases in two. For 12 patients the only metastatic deposit found was a micrometastasis (≤2 mm) in a sentinel node. In the 72 patients with detectable sentinel nodes, pathological analysis of the sentinel node correctly categorized 71 and ePLND 70 patients. Conclusions. This protocol yielded results comparable to the commonly used technique of sentinel-node detection, but with more cases of non-detection.

18F]fluoromethylcholine (FCH) positron emission tomography/computed tomography (PET/CT) for lymph node staging of prostate cancer: a prospective study of 210 patients

Study Type--Diagnostic (exploratory cohort) Level of Evidence 2a. What's known on the subject? and What does the study add? Staging of patients with prostate cancer is the cornerstone of treatment. However, after curative intended therapy a high portion of patients relapse with local and/or distant recurrence. Therefore, one may question whether surgical lymph node dissection (LND) is sufficiently reliable for staging of these patients. Several imaging methods for primary LN staging of patients with prostate cancer have been tested. Acceptable detection rates have not been achieved by CT or MRI or for that matter with PET/CT using the most common tracer fluoromethylcholine (FCH). Other more recent metabolic tracers like acetate and choline seem to be more sensitive for assessment of LNs in both primary staging and re-staging. However, previous studies were small. Therefore, we assessed the value of [(18) F]FCH PET/CT for primary LN staging in a prospective study of a larger sample and with a 'blinded' review. After a study period of 3 years and >200 included patients, we concluded that [(18) F]FCH PET/CT did not reach an optimal detection rate compared with LND, and, therefore, it cannot replace this procedure. However, we did detect several bone metastases with [(18) F]FCH PET/CT that the normal bone scans had missed, and this might be worth pursuing. • To assess the value of [(18) F]fluoromethylcholine (FCH) positron emission tomography/computed tomography (PET/CT) for lymph node (LN) staging of prostate cancer. • To evaluate if FCH PET/CT can replace LN dissection (LND) for LN staging of prostate cancer, as about one-third of patients with prostate cancer who receive intended curative therapy will have recurrence, one reason being undetected LN involvement. • From January 2008 to December 2010, 210 intermediate- or high-risk patients had a FCH PET/CT scan before regional LND. • After dissection, the result of histological examination of the LNs (gold standard) was compared with the result of FCH PET/CT obtained by 'blinded review'. • Sensitivity, specificity, positive (PPV), and negative predictive values (NPV) of FCH PET/CT were measured for detection of LNe metastases. • Of the 210 patients, 76 (36.2%) were in the intermediate-risk group and 134 (63.8%) were in the high-risk group. A medium (range) of 5 (1-28) LNs were removed per patient. • Histological examination of removed LNs showed metastases in 41 patients. Sensitivity, specificity, PPV, and NPV of FCH PET/CT for patient-based LN staging were 73.2%, 87.6%, 58.8% and 93.1%, respectively. • Corresponding values for LN-based analyses were 56.2%, 94.0%, 40.2%, and 96.8%, respectively. • The mean diameter of the true positive LN metastases was significantly larger than that of the false negative LNs (10.3 vs 4.6 mm; P < 0.001). • In addition, FCH PET/CT detected a high focal bone uptake, consistent with bone metastases, in 18 patients, 12 of which had histologically benign LNs. • Due to a relatively low sensitivity and a correspondingly rather low PPV, FCH PET/CT is not ideal for primary LN staging in patients with prostate cancer. • However, FCH PET/CT does convey important additional information otherwise not recognised, especially for bone metastases.