ABSTRACT
Somatostatin (SST) receptor (R) (SSTR) scintigraphy has improved the ability to diagnose and detect, stage disease, and review the response to therapy in patients with neuroendocrine tumors. Many other tumor entities are also candidates for SSTR mediated therapy, including thyroid cancer, brain tumors, melanoma, breast cancer, and thymoma. The biodistribution of 111In-DTPA-D-Phe1-octreotide as well as of 111In-/90Y-DOTA-D-Phe1-Tyr3-octreotide differs from that of 111In-/90Y-DOTA-lanreotide in terms of higher liver and kidney, and less bone marrow uptake. The MAURITIUS (Multicenter Analysis of a Universal Receptor Imaging and Treatment Initiative, a European Study) trial was initiated in 1997 at the University of Vienna, and several centers throughout Europe have treated tumor patients with 90Y-DOTA-lanreotide. Data reported here are based on results from studies in Cesena, London, Milano, Innsbruck, and Vienna. At most centers, comparative scintigraphy with 111In-DTPA-D-Phe1-octreotide or 111In-DOTA-D-Phe1-Tyr3-octreotide was performed for tumor evaluation. Dosimetric studies were performed to predict individual tumor doses and doses for the critical organs. Patients (n = 235) with neuroendocrine tumors, thymoma, thyroid cancer, brain tumors, lymphoma, intestinal adenocarcinoma, or other rare tumors, received up to a total of 8.5 GBq of 90Y-DOTA-lanreotide 210in up to seven treatment applications. The therapeutic agent of 90Y-DOTA-lanreotide was given either intravenously (121 patients), intraarterially (21 patients), or by local intratumoral injection (93 patients). Patients were at a stage of progressive disease when entering treatment. During the follow-up period, disease was evaluated by repeated scintigraphy and computer tomography/magnetic resonance imaging, documenting the response to therapy (in terms of stable disease, progressive disease, partial remission, or complete remission), as well as by documenting the time of progression of disease and quality of life parameters. Overall results indicate that beneficial effects can be suspected from therapy with 90Y-DOTA-lanreotide. An update of the five years follow-up period indicated that 37% (40/109) of the patients treated with 90Y-DOTA-lanreotide had stable disease and 17% (18/109) partial remission of tumor lesions. Objective response of quality of life measurements was documented in 10–20% of patients, and subjective response was found in 30–50% of patients. So far, results of the MAURITIUS trial indicate that radiolabeled SST analogs may be considered in patients with SSTR-positive tumors for size reduction and improvement of quality of life paramaters.
