Nodal staging

Abstract

Lymph node metastases are a poor prognostic indicator in many tumours and therefore accurate identification during staging is important prior to commencing treatment. The presence of lymph node metastases can significantly alter patient management and therefore accurate diagnosis of the presence and extent of nodal disease can help optimise patient management. In this review, the radiologic features that aid in the differentiation of malignant and benign lymph nodes are discussed. The keys to successful interpretation on cross-sectional computed tomography (CT) and magnetic resonance imaging of nodal metastases are highlighted. The clinical role of positron emission tomography-CT imaging for nodal staging is discussed and emerging imaging techniques that may further improve nodal staging accuracy are surveyed.

Figure 1

(A) An ultrasound demonstrating a normal lymph node in a 24-year-old man. (B) An ultrasound demonstrating fine-needle aspiration of an irregular right supraclavicular lymph node in a 46-year-old woman with breast cancer.

Figure 2

A coronal STIR image demonstrating a high signal intensity node(arrow) at right level II region in a 67-year-male patient with squamous cell cancer of the oropharynx.

Figure 3

An axial contrast-enhanced CT demonstrating an enlarged heterogeneous right external iliac lymph node (arrow) in a 64-year-old patient with endometrial cancer.

Figure 4

An axial contrast-enhanced CT demonstrating a large left common iliac cystic lymph node (arrow) in a 34-year-old man with a germ cell tumour.

Figure 5

(A) T1-weighted axial image of the pelvis demonstrating multiple enlarged inguinal lymph nodes (arrow) which are low signal in a 61-year-old woman with cervical cancer. (B) Fat-saturated post-contrast images of the pelvis demonstrating multiple enlarged inguinal lymph nodes (arrow) which are of high signal in a 61-year-old woman with cervical cancer.

Figure 6

A PET-CT image demonstrating a right obturator lymph node (arrow) in a 29-year-old woman with small cell carcinoma of the cervix.

Figure 7

Normal sidewall nodes (arrows) imaged using T2*-weighted MR imaging (MEDIC) (A) before and (B) 24 h after USPIO contrast administration in a 57-year-old man with rectal cancer. Prior to contrast administration, blood vessels and lymph nodes have relatively high signal intensity. Note signal darkening of the normal nodes after contrast, thus facilitating their detection.