Studies of at least 10 patients with histologically proven primary carcinoma that evaluated gadolinium enhanced MRI (index test) compared to histopathology of lymph nodes obtained by surgery, autopsy or biopsy (reference standard) were eligible for inclusion if they reported sufficient data to construct a 2x2 table of test performance. Studies of health volunteers only or patients with non-lymphatic metastases were excluded.
Included studies evaluated patients with colon/rectal, cervical, breast, lung, head and neck, oesophageal, pancreatic, renal cell, urinary bladder, gall bladder, endometrial, ovarian and gastric cancers. Mean age at diagnosis was 58 years.
One reviewer screened the results of the searches and two reviewers independently assessed full-text studies for inclusion. Disagreements were resolved through referral to a third reviewer.