Observations on the sequential use of Tc-99m phosphonate and Ga-67 imaging in untreated primary and secondary malignant tumors of the head and neck.

Scintigraphy using both Tc-99m phosphonate and Ga-67 was performed in 55 cases of untreated primary and secondary tumors of the head and neck. In 21 patients with primary tumors of jaws, eye, tongue, or parotid gland, Ga-67 scintigraphy visualized the primary tumor in all cases and metastases in 12. Scintigraphy using Tc-99m phosphonate disclosed primary bone involvement in 12 cases and skeletal metastases in two. In eight of 13 patients with metastatic lesions of jaws and skull, bone scintigraphy showed skeletal metastases. In seven of these patients, Ga-67 scintigraphy detected the primary tumor and in 11 cases detected metastases. Bone scintigraphy disclosed skeletal metastases in six of 21 patients with malignant neck tumors. In 13 of these patients, Ga-67 scintigraphy visualized the primary tumor, whereas it showed metastases in seven. It is concluded that Ga-67 scintigraphy should be used in the investigation of untreated primary or secondary malignant tumors of the head and neck. Bone scintigraphy may be indicated as an additional study in selected cases only.