Peptide receptor radionuclide therapy as a potential tool for neoadjuvant therapy in patients with inoperable neuroendocrine tumours (NETs)

Abstract

PurposeNeuroendocrine tumours (NET) are a heterogeneous group of neoplasms of diffuse neuroendocrine cells. Surgery is the main aim in the treatment of NETs, which becomes impossible in the case of large tumours or infiltration into other tissues and/or important blood vessels. Neoadjuvant therapy might be helpful in decreasing NET size also, leading us to the point where a tumour, previously considered inoperable, becomes operable. The aim of the study was to assess the usage of peptide receptor radionuclide therapy (PRRT) as a neoadjuvant treatment, enabling surgical intervention in primary inoperable NET.MethodsAmong 47 patients treated with PRRT, 6 patients were chosen with large, inoperable tumours, for whom enabling of complete surgical excision of the lesions might offer the prospect for a cure. Response to the therapy was assessed according to Response Evaluation Criteria In Solid Tumors (RECIST).ResultsThe mean tumour size decreased from 6.9 (min. 3.1 cm, max. 9.6 cm) before therapy to 5.4 cm (min. 3.1 cm, max. 9.5 cm) after the treatment. According to RECIST, stabilization of the disease was observed in four and partial responses in two patients. In two patients, reduction of the tumour size enabled surgical intervention.Conclusion(1) PRRT might be considered a neoadjuvant therapy in primary inoperable NETs. (2) According to RECIST, stabilization of the disease was observed in the majority of patients. (3) We suggest that not only tumour diameter changes, but also tumour volume and contrast enhancement changes in computed tomography should be taken into consideration in assessment of the response to the therapy. (4) Somatostatin receptor scintigraphy is an important tool for qualification of the radioisotope therapy and also for the assessment of the response to PRRT.

Neoadjuvant Treatment of Nonfunctioning Pancreatic Neuroendocrine Tumors with [177Lu-DOTA0,Tyr3]Octreotate

“…Three patients received 90 Y-based somatostatin analogs (10)(11)(12), and 2 patients 177 Lu-based somatostatin analogs (13,14). Although these case reports demonstrate the potential of PRRT in a neoadjuvant setting, follow-up after surgery was limited.…”

“…A few case reports have described the use of PRRT as neoadjuvant treatment in patients with pancreatic NETs (10)(11)(12)(13)(14). Here, we describe our experience with [ 177 Lu-DOTA 0 ,Tyr 3 ]octreotate ( 177 Lu-octreotate) treatment of a large series of patients with nonfunctioning pancreatic NETs in a neoadjuvant setting with a long follow-up.…”

Update on Surgical Management of Small Bowel Neuroendocrine Tumors

“…There are small series indicating that immunotherapy or PRRT, or both, may improve the possibility of achieving R0 resection (58).…”

Nowotwory neuroendokrynne trzustki — zasady diagnostyki i leczenia (rekomendowane przez Polską Sieć Guzów Neuroendokrynych)

“…PRRT may also be considered as a neoadjuvant treatment in tumours inoperable due to a significant local advancement [6,246]. Radiolabelled with 90 Y and 177 Lu somatostatine analogues were used in PNET as a neoadjuvant therapy.…”