Tomomitsu Higashi

Gallium-67 imaging in the evaluation of thyroid malignancy

One hundred thirty-six patients with suspected thyroid malignancy were studied prospectively with Ga-67 imaging of the thyroid and whole body. All patients subsequently had diagnoses proven by biopsy or surgical resection. Patients with malignant tumors (anaplastic carcinoma, malignant lymphoma, adenocarcinoma, medullary carcinoma, adenocarcinoma with squamous cell transformation, and metastases to the thyroid from other tumors) were examined serially after appropriate therapy. The authors draw on their own experience and a literature review to propose the following indications for Ga-67 imaging in patients with thyroid disease: 1) suspected anaplastic carcinoma or malignant lymphoma of the thyroid gland, 2) detection of distant metastases of anaplastic thyroid carcinoma and malignant lymphoma, 3) evaluation of efficacy of therapy, 4) suspected metastases to the thyroid gland from other malignancies, and 5) differentiation of malignant lymphoma from chronic thyroiditis. The strengths, limitations, and potential pitfalls of the technique are discussed.

Gallium-67 Scanning in the Differentiation of Maxillary Sinus Carcinoma from Chronic Maxillary Sinusitis

Gallium-67 scans of 25 patients in whom the clinical symptoms and radiographic findings were suggestive of either maxillary sinus carcinoma or chronic sinusitis proved to be valuable in the differentiation between the two disease processes. Those patients with carcinoma had positive scans, while those with sinusitis had either negative or only weakly positive scans.

Identification of Warthin's tumor with technetium-99m pertechnetate.

Salivary gland imaging with Tc-99m pertechnetate is a useful procedure for evaluating the functional status of salivary glands. The only neoplasms of salivary glands known to consistently concentrate Tc-99m pertechnetate are Warthins tumor and oncocytoma. In the five cases presented, increased concentration of Tc-99m pertechnetate was seen in these tumors of the parotid glands. This finding was useful for preoperative identification of Warthins tumor. During this investigation, the concentration of Tc-99m pertechnetate in Warthins tumor varied by histologic type. Thus, a dynamic study may be helpful in evaluating the accumulation rate of Tc-99m pertechnetate into this tumor type. Because the retention of Tc-99m pertechnetate in tumor following stimulation is useful for the diagnosis of Warthins tumor, a washout image is of importance in establishing this diagnosis.

Ga-67 scan as a prognostic indicator in primary lung carcinoma.

Ga-67 scintigraphy was performed on 74 patients with a variety of histologic types of untreated primary lung carcinoma. Ga-67 uptake was determined, allowing for differences in tumor size. Ga-67 uptake was compared with the response to the incidence of metastases, and to host survival in the 74 patients. From these results, it is suggested that the greater the Ga-67 accumulation in the tumor, the higher the incidence of metastases and the shorter the host survival. Ga-67 scintigraphy appears to be a valuable tool in indicating the prognosis following radiation therapy in patients with primary lung carcinoma.

Technetium-99m pertechnetate and Gallium-67 imaging in salivary gland disease

Thirty–two patients with salivary gland tumors or sialadenitis were studied with Tc–99m pertechnetate and Ga–67 imaging and, in some instances, sialography. The diagnostic algorithm presented allows the correct categorization of the salivary gland pathology in the vast majority of patients. The patients were studied serially with Tc–99m pertechnetate, Ga–67, and in certain situations sialography (or CT–sialography). Use of the algorithm can distinguish benign salivary tumors from malignant tumors and malignant tumors from inflammatory disease. The limitations and pitfalls of interpretation are discussed.

The relationship between Ga-67 accumulation and cell cycle in malignant tumor cells in vitro

Previously we reported that the deposition of 67Ga into malignant tumor may be a sensitive index of proliferative activity in tumor cells. For the purpose of elucidation of this hypothesis, we investigated the relationship between the accumulation of 67Ga into malignant tumor cells and the cell cycle in vitro. We discovered that the uptake of both 67Ga and 59Fe into synchronized mouse tumor cells reaches a peak at the G2 stage which precedes cellular proliferation. Both iron and transferrin are specifically required by cells in culture for cell division, and the fact that 67Ga and 59Fe uptake into tumor cells peaks at the G2 stage of the cell cycle suggests that there is a correlation between 67Ga uptake and the rate of cellular proliferation in malignant tumor cells.

The relationship between 67Ga accumulation and ATP metabolism in tumor cells in vitro

Previously, we reported that the deposition of 67Ga into malignant tumors may be a sensitive index of proliferative activity in tumor cells. For the purpose of elucidation of this hypothesis, we investigated the relationship between the accumulation of 67Ga into malignant tumor cells and the intra cellular ATP metabolism in vitro.The uptake of 67Ga into tumor cells was inhibited by adding NaF which is an inhibitor of ATP production. Furthermore, the uptake of 67Ga into tumor cells was strongly inhibited by adding ouabain which is a specific inhibitor of Na+−K+-ATPase. From these in vitro results, it was concluded that there is a correlation between 67Ga uptake and intra cellular ATP metabolism in tumor cells.

Salivary gland uptake of gallium-67 citrate after sialography.

Sialography may cause greatly increased Ga-67 activity within otherwise normal salivary glands. Five patients are presented in whom sialography with oily contrast material injected 8–26 days before Ga-67 imaging produced strongly positive examinations. In each patient it appears that sialography rather than pre-existing pathologic conditions accounted for the increased activity. Sialography-induced subclinical sialadenitis may be the mechanism for the phenomenon.

Identification of Warthin's tumor with 99mTc. Report of a case.

Abstract Nuclear imaging of the salivary glands with 99m Tc-pertechnetate and the gamma camera reveals increased accumulation in the right parotid gland facilitating a diagnosis of Warthins tumor.

Clinical evaluation of 67Ga-citrate scanning in the oral region.

Gallium-67-citrate was administered to thirty-nine patients who had a variety of benign, malignant, and inflammatory lesions of the oral region. The gallium-67 scintigram was noted to be valuable in the diagnosis of maxillary carcinoma, parotid carcinoma, and malignant lymphoma. Clinically, it is possible to differentiate malignant tumors from benign ones with the aid of 67Ga scanning. It is difficult, however, to differentiate malignant tumors from inflammatory lesions. At present, it is difficult to defect the small malignant lesion by means of a 67Ga scintigram.