Somatostatin receptor scintigraphy in postsurgical follow-up examinations of meningioma.

UNLABELLED

Surgery is the treatment of choice in patients with meningioma. However, the risk of postoperative, local recurrence is well-known since total resection is not always feasible. Moreover, in these patients MRI may fail to differentiate between tumor remnants, recurrent meningioma or nonspecific hyperperfusion. In this study, the value of functional imaging using somatostatin receptor scintigraphy (SRS) was evaluated in postsurgical follow-up.

METHODS

Before and 2-3 mo after surgery, 27 patients with meningioma received MRI as well as SRS after intravenous injection of 200 MBq 111In-octreotide. Planar whole-body images were obtained at 10 min, 1, 4 and 24 hr postinjection, and SPECT was performed at 4 and 24 hr postinjection. The final diagnosis was proven histologically in all patients.

RESULTS

Before surgery, MRI showed focal contrast enhancement in all patients, and SRS revealed focal accumulation of 111In-octreotide. Thus, MRI and SRS yielded comparable results in all 27 patients. After surgery, MRI showed diffuse contrast enhancement in the area of the primary tumor site in all patients. Thus, MRI did not allow a differentiation between tumor and nonspecific hyperperfusion. In contrast, SRS revealed focal accumulation of 111In-octreotide in 16 of 27 patients indicating remaining tumor tissue or relapse of meningioma. This resulted either in an operative revision or in more frequent postsurgical follow-up examinations. In 11 of 27 patients, SRS was negative. Thus, total resection of meningioma was assumed, and no further interventions were performed.

CONCLUSION

Functional imaging using SRS is a highly specific imaging modality and has a significant impact in postsurgical follow-up in patients with meningioma.