Current Imaging Techniques for Lymph Node Staging in Prostate Cancer: A Review

Introduction: Lymph node metastases (LNM) represent a proven prognostic factor for biochemical recurrence (BCR)-free survival, metastatic free survival and overall survival in prostate cancer (PCa). Although pelvic node dissection remains the gold standard for the detection of LNM, novel imaging techniques are entering clinical practice, in the effort to improve LNM detection and spare unnecessary surgeries. Aim of the current review is to describe such imaging techniques and explore their advantages and limitations.Evidence Acquisition: The National Library of Medicine Database was searched for relevant articles published between January 2013 and August 2018. A wide search was performed including the combination of following words: “Prostate” and “Cancer” and “staging” and “Lymph Node” and “imaging” and (“MRI” or “PET”). The initial list of selected papers was enriched by individual suggestions of the authors of the present review.Evidence Synthesis: DWI-MRI in detection of lymph node invasion has a sensitivity and specificity of 41 and 94%, respectively. For SPIO MRI using ferumoxtran-10, the sensitivity for detection of LNM with short axis diameter of 5–10 mm is reported at 96.4%, compared to 28.5% with MRI alone. PSMA PET/CT is growing exponentially, both in the initial detection of LNM and for BCR evaluation. Fluciclovine PET could improve detection of subcentimetric pathologic lymph nodes. Sentinel lymph node techniques remain experimental and not validated in the field of PCa.Conclusions: Molecular imaging, particularly PSMA ligand PET imaging, present interesting diagnostic accuracy in LN diagnosis even in subcentimetric LN. DWI-MRI yields good results in LN involvement evaluation and the use of contrast agent such SPIO may improve the detection rate. The SLN technique is limited to experimental protocols and for intermediate or high-risk PCa. Prospective trials are awaited to evaluate the true clinical impact of these imaging techniques on PCa oncologic outcomes

La tomographie par émission de positons des indications classiques aux applications récentes et futures

First clinical indications of positron emission tomography (PET) were in the fields of neurology and cardiology, but oncology is the domain in which PET got its recognition as an essential diagnostic tool. Its fast diffusion as an imaging method for diagnosis and follow-up of cancer has been facilitated by the existence of a single tracer for all kinds of oncological PET explorations. Nowadays, this tracer, fluorodeoxyglucose (FDG) is so largely distributed that non oncological PET indications have emerged. For instance, PET with FDG has totally supplanted gallium-67 for the evaluation of inflammatory conditions. Another non oncological domain in which PET with FDG has kept an important clinical role is neurology. The strong local relationship between neuronal activity and cerebral glucose uptake confers to PET with FDG a primordial role in neurological conditions in which structural changes are insufficient to establish a firm diagnosis. This is the case for focal epilepsy that remains an undisputed indication of PET with FDG, and for neurodegenerative disorders, in particular those that lead to dementia for which tracers detecting amyloid and tau depositions are now available. New tracers have enlarged PET indications in oncology, in particular for cancers that are not well evaluated with FDG. Since the early clinical PET introduction, patients with brain tumours are benefiting from PET exploration with amino-acid tracers, in particular for therapeutic tumour targeting. The recent development of tracers for neuroendocrine and prostatic cancers has opened a new field of applications for PET, linked to innovative radiotherapeutic approaches.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

An Exceptional Cause of Increased ¹⁸F-Fluorodeoxyglucose Uptake on PET/CT in a Thyroid Nodule

A 41-year-old female underwent a cervical spine CT for the workup of posterior neck pain irradiating to the shoulders for several months. An incidental thyroid nodule was found and classified as Bethesda III on the Fine-needle aspiration cytology (FNAC) results. Three months later, the patient developed mild shortness of breath, dry cough, and fever. Chest X-ray revealed a mild enlargement in the bilateral hilar regions. CT showed mediastinal and bilateral hilar enlarged lymph nodes and pulmonary micronodules. The workup was further completed with a 18F-FDG PET/CT, showing intense FDG uptake in the mediastinal and bilateral hilar lymph nodes and increased uptake in the thyroid nodule. Endobronchial Ultrasound-guided Transbronchial needle aspiration (EBUS-TBNA) of a left hilar lymph node showed epithelioid non-necrotizing granulomas. Because of the FNAC results, size of the nodule and tracheal shift, thyroid lobectomy was performed one month later. Histopathological results also revealed multiple non-necrotizing epithelioid granulomas, suggesting systemic sarcoidosis with involvement of the thyroid. To our knowledge, this is the first report of thyroid sarcoidosis detected on 18F-FDG PET/CT. Although an increased FDG uptake in a thyroid nodule is usually suggestive of thyroid malignancy, toxic nodule, or follicular hyperplasia, our case report shows that it could also suggest thyroid sarcoidosis

Unusual diffuse liver 18F-FDG uptake in melanoma patient treated by ipilimumab

We present herein a case of unusual 18F-FDG PET-CT diffuse hypermetabolic liver uptake in melanoma patient treated by ipilimumab.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Prognostic value of a three-scale grading system based on combining molecular imaging with 68Ga-DOTATATE and 18F-FDG PET/CT in patients with metastatic gastroenteropancreatic neuroendocrine neoplasias

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The metabolic clinical risk score as a new prognostic model for surgical decision-making in patients with colorectal liver metastases

Background and Objectives: Selection for surgery in patients with colorectal liver metastases (CRLM) remains inaccurate. We evaluated if CRLM baseline metabolic characteristics, assessed by [18]F-fluorodeoxyglucose-positron emission tomography/computed tomography (18FDG-PET/CT), could predict postoperative outcomes. Methods: In a retrospective series of patients undergoing surgery for CRLM, we defined two groups: the long-term survival (LTS) and early relapse (ER) groups, where the postoperative recurrence-free survivals were ≥5 years or 4.3, defining low- and high-risk mCRS by scores of 0 to 2 and 3 to 6, respectively. Results: From a series of 450 patients operated for CRLM (mean follow-up of 58 months), we included for analysis 23 and 30 patients in the LTS and ER groups, respectively. Clinicopathologic parameters and CRS were similar in the LTS and ER groups. Median SUVmax/SUVmean(liver) ratios were higher in ER vs LTS patients (4.2 and 2.8, P =.008, respectively). mCRS was increased in ER patients (P =.024); 61% of LTS patients had low-risk mCRS and 73% of the ER patients had high-risk mCRS (P =.023). Conclusions: 18FDG-PET/CT characteristics combined with traditional CRS may represent a new tool to improve selection for surgery in patients with CRLM.SCOPUS: ar.jinfo:eu-repo/semantics/publishe