gms | German Medical Science

Objective: Cranial meningiomas are mostly benign tumors with a favorable prognosis after resection. In the case of local recurrence repeated resection with/ -out adjuvant radiotherapy is the treatment of choice. In rare cases, however, conventional treatment algorithms fail to achieve long-lasting tumor control. Here, Lu-177 labeled DOTATATE, an analogue for the somatostatin receptor II which is ubiquitously expressed by meningiomas, might be a new systemic treatment option.

Method: A retrospective analysis was performed on highly selected meningioma patients in whom compassionate off-label use of Lu-177 DOTATATE treatment was found indicated by our interdisciplinary tumor board between 02/2012 and 10/2014. Patients were then treated with 4 cycles of Lu-177 DOTATATE (standard dose: 7400 MBq per cycle). In most patients, DOTATATE-PET-CT was obtained before and after therapy as well as MRI after 2 and 4 cycles. Clinical examinations, renal scintigrams and laboratory tests were repeatedly performed during therapy and at regular follow-up visits.

Results: Overall, 9 patients were identified with meningioma recurrence after multimodal treatment. These patients had undergone a mean of 4 resections (range 2 to 7) and 2 times radiation therapy (range 1-3) prior to Lu-177 DOTATATE therapy. Histological diagnosis of latest tissue samples were 4 WHO grade I, 3 WHO grade II and 2 WHO grade III. 3 patients died due to progressive disease before 4 cycles could be completed. Mean follow-up of the remaining 6 patients was 6 months after therapy. 3 patients were found to have stable disease and 3 showed a mixed response with some tumors parts being stable or even regressing and some parts progressing at last follow-up. 1 patient required additional tumor resection 16 months after DOTATATE therapy due to a progressive space-occupying lesion. 1 patient developed pituitary insufficiency and 3 patients exhibited transient and asymptomatic decreases in renal function.

Conclusions: Lu-177 DOTATATE treatment might be considered as salvage therapy in highly selected patients with progressive meningiomas after failure of conventional therapy. Tumor response can be expected in a subgroup of patients. Why tumors respond differently remains the subject of further investigation. Given the reasonable safety record in our case series, we think that further prospective studies to evaluate Lu-177 DOTATATE therapy in uncontrolled meningioma are warranted.