BONE METASTASES IN PATIENTS WITH GASTRINOMAS - A PROSPECTIVE-STUDY OFBONE SCANNING, SOMATOSTATIN RECEPTOR SCANNING, AND MAGNETIC-RESONANCEIMAGE IN THEIR DEFECTION, FREQUENCY, LOCATION, AND EFFECT OF THEIR DETECTION ON MANAGEMENT

Purpose: To determine whether bone scan, magnetic resonance imaging (M RI), or somatostatin receptor scintigraphy (SRS) is best for identifyi ng bone metastases in patients with gastrinomas, as well as their freq uency and location, whether their detection affects management, and wh at patient subgroups should be examined. Materials and Methods: One hu ndred fifteen patients with gastrinoma were prospectively studied. Pat ients were examined yearly and those with liver metastases were reexam ined every 3 months. Based on clinical history, histology, growth patt ern, and development of new bone lesions, possible bone metastases wer e classified as to whether they were or were not bone metastases. Imag ing results were correlated at different times in the disease course a nd with disease extent. Results: Bone scan was positive in 52 patients , MRI in seven, and SRS in six. Eight patients (7%) were determined to have bone metastases and MRI was correctly positive in seven, SRS in six, and bone scan in five. SRS or MRI was positive in all patients wi th bone metastases. Bone scan had significantly lower specific-ity and sensitivity, and a higher rate (P < .02) of false-negative results th an MRI or SRS. Bone metastases occurred in 31% of patients with liver metastases and 0% with only lymph node metastases. The initial bone me tastases were in the spine or sacrum (75%) followed in descending orde r by the pelvis or sacroiliac joints (38%), scapula or shoulder, and r ibs. In all cases, detection of bone metastases changed the management . Conclusion: SRS and MRI, because of high sensitivity and specificity , are recommended over bone scanning to screen for bone metastases in patients with gastrinomas. However, because bone metastases can occur initially outside the axial skeleton, SRS is the recommended initial l ocalization method of choice. Bone metastases occur in 7% of all patie nts and 31% of patients with liver metastases, only occur in patients with liver metastases, are usually in the axial skeleton initially, an d their detection changes management in all cases. Patients with pancr eatic endocrine tumors with liver metastases should undergo SRS every 6 months to 1 year to detect bone metastases. This is a US government work. There are no restrictions on its use.