Does supplementation of CT and MRI with gallium-67 SPECT improve the differentiation between benign and malignant tumors of the head and neck?

UNLABELLED: The objective of our study is to determine whether 67Ga SPECT can supplement CT and/or MRI diagnostic information by visual comparison of the two separate data sets in patients with head and neck tumors.

METHODS: A total of 50 patients with head and neck tumors (benign: 19, malignant: 31) were entered in the study. Three board-certified radiologists who had practical experience in interpreting both head and neck CT/MRI and 67Ga SPECT images, participated as readers. All of the CT and/or MR images of each patient were shown to each reader first, who after they had finished interpreting them were shown the 67Ga SPECT images. They were asked to score each image on a 7-point scale for the likelihood of the presence or absence of malignancy. Histological or cytological evaluation was done in all cases, and the radiologic studies were correlated with these findings.

RESULTS: Improvement of all three readers' performance was from 70.7% to 83.3% in the mean accuracy and from 0.790 to 0.921 in the mean Az value (p = 0.033, 0.163, 0.105 in the Az values) after they were shown the 67Ga SPECT images.

CONCLUSIONS: 67Ga SPECT should substantially increase confidence in the diagnosis of head and neck tumors when CT and/or MRI do not permit differentiation between benign and malignant disease.