Detection of lymph nodes in pelvic malignancies with computed tomography and magnetic resonance imaging

Radiologic Assessment of Lymph Nodes in Oncologic Patients

“…In a study about LN detection of pelvic malignancies, Saokar et al reported that MRI detected more LNs compared to CT in all nodal regions, including the external iliac, obturator, and internal iliac chains. Based on size, the numbers of nodes detected by CT and MRI were equal when nodal size above 10 mm; however, when size is 1-5 mm, MRI is capable to detect more nodes [36]. In a MRI study of pelvic LNs in cervical carcinoma, Yang et al obtained a higher sensitivity and specificity of 70.6 and 89.8 %, respectively, using a size threshold of 1 cm in long axis diameter or the presence of central necrosis [37].…”

Contemporary role of advanced imaging for bladder cancer staging

“…Up to 25% of patients with lymph node metastases found on final pathology were not visualized on imaging characterization before undergoing radical cystectomy. This realized nodal understaging with conventional imaging, is a result of simply using size parameters as an indirect surrogate for predicting metastatic involvement with reported sensitivity of detecting lymph node positivity in cases of bladder cancer taken to radical cystectomy ranging between 31% and approximately 50% [22,[24][25][26]. Specificity of CT imaging based on size criteria has been reported between 68% and 100%, but falls short of consistently perfect correlation with pathology owing to enlargement of lymph nodes secondary to reactive inflammatory etiologies often propagated by prior intervention or medication administration common in this patient population who has undergone prior TURBT and possibly preoperative intravesical or systemic therapies.…”

Lymph Node Staging in Prostate Cancer

“…For both modalities, the definition of suspicious LNs is based mostly on size thresholds for enlarged LNs. The most commonly used threshold is 10 mm in short axis diameter [6]. However, recommended thresholds vary from 8 to 15 mm [7–10].…”