Erratum to: Long-term follow-up and role of FDG PET in advanced pancreatic neuroendocrine patients treated with 177Lu-D OTATATE

In the ‘Authors’ contributions’ section, ‘Study concept and design’ was attributed to Maddalena Sansovini when in actual fact it should have been attributed to Giovanni Paganelli

Role of 18FDG PET/CT in patients treated with 177Lu-DOTATATE for advanced differentiated neuroendocrine tumours

Purpose The prognostic value of FDG PET for neuroendocrine tumours (NETs) has been reported. In this study we evaluated the role of FDG PET in predicting response and progression-free survival (PFS) after 177Lu-DOTATATE peptide receptor radionuclide therapy (Lu-PRRT) in patients with advanced well-differentiated grade 1/2 NETs. Methods We retrospectively evaluated 52 patients with progressive advanced NETs overexpressing somatostatin receptors and treated with Lu-PRRT with a cumulative activity up to 27.7 GBq divided into five courses. According to WHO 2010/ENETS classification, patients were stratified into two groups: those with grade 1 tumour (Ki-67 index â\u89¤2 %, 19 patients), and those with grade 2 tumour (Ki-67 index >3 % to 2.5) were frequently associated with more aggressive disease. PET+ patients with grade 2 NET, 32 % of whom did not respond to Lu-PRRT monotherapy, might benefit from more intensive therapy protocols, such as the combination of chemotherapy and PRRT. © 2013 Springer-Verlag Berlin Heidelberg

177 Lu-Dota-octreotate radionuclide therapy of advanced gastrointestinal neuroendocrine tumors: results from a phase II study

PURPOSE: We evaluated the activity and safety profile of (177)Lu-Dotatate peptide receptor radionuclide therapy (Lu-PRRT) in patients with advanced, well-differentiated (G1-G2) gastrointestinal neuroendocrine tumors (GI-NETs).METHODS: Forty-three patients with radiological tumor progression at baseline and a positive Octreoscan® completed the treatment with Lu-PRRT, resulting in the cumulative activity of 18.5 or 27.8 GBq in five cycles. Total activity was scheduled on the basis of kidney function or bone marrow reserve.RESULTS: Twenty-five (58 %) patients were treated with a "standard" Lu-PRRT full dosage (FD) of 25.7 GBq (range 22.2-27.8), while the remaining 18 patients (42 %) who, at enrolment, showed a higher probability of developing kidney or bone marrow toxicity received a reduced dosage (RD) of 18.4 GBq (range 14.4-20.4). According to SWOG criteria, the overall response was complete response (CR) in (7 %) cases and stable disease (SD) in 33 (77 %), with a disease control rate (DCR) of 84 %. Median response duration was 25 months (range 7-50). Median progression-free survival (PFS) was 36 months (95 % CI 24-nr), and median overall survival (OS) has not yet been reached. Remarkably, none of the patients, including those at a higher risk of toxicity, showed side-effects after either dosage of Lu-PRRT.CONCLUSION: Lu-PRRT was shown to be an effective therapeutic option in our patients with advanced progressive GI-NETs, showing an 84 % DCR (95 % CI 73-95) that lasted for 25 months and a PFS of 36 months. Both activities of 27.8 GBq and 18.5 GBq proved safe and effective in all patients, including those with a higher probability of developing kidney or bone marrow toxicity

Investigation of receptor radionuclide therapy with177Lu-DOTATATE in patients with GEP-NEN and a high Ki-67 proliferation index

Purpose: In the 2010 WHO classification, a Ki-67 proliferation index of 20% is the cut-off between intermediate-grade and high-grade gastroenteropancreatic neuroendocrine neoplasia (GEP-NEN). However, in clinical practice, tumours with a Ki-67 index of >15% are often considered high grade and treated with chemotherapy. In 40–70% of high-grade NENs, somatostatin receptors are overexpressed, enabling peptide receptor radionuclide therapy (PRRT) to be performed. We investigated the role of PRRT with177Lu-DOTATATE in patients with GEP-NEN and a high Ki-67 proliferation index. Methods: A total of 33 patients with advanced GEP-NENs, positive somatostatin receptor imaging (SRI+) and a Ki-67 proliferation index ranging from 15% to 70% were treated with Lu-PRRT. A cumulative activity of 18.5 GBq or 27.8 GBq of177Lu-DOTATATE was administered in four or five cycles. Receiver operating characteristic (ROC) curve analysis was used to determine the best threshold of Ki-67 expression to predict disease progression. Results: All patients completed the intended treatment. The median follow-up was 43 months (range 3–69 months). Two patients (6%) achieved a partial response and 21 (64%) showed stable disease, giving a disease control rate (DCR) of 70%. The median progression-free survival (PFS) was 23 months (95% CI 14.9–31.0 months) and the median overall survival was 52.9 months (95% CI 17.1–68.9 months). ROC curve analysis at 23 months revealed that the best Ki-67 index cut-off was 35%. In 23 patients (70%) the Ki-67 index was ≤35% and in 10 patients (30%) the Ki-67 index was in the range 36–70%. The DCR in the former group was 87% and 30% in the latter. The median PFS was 26.3 months (95% CI 18.4–37.7 months) and 6.8 months (95% CI 2.1–27 months), respectively (p = 0.005). Conclusions: Lu-PRRT showed antitumour activity in SRI+ GEP-NENs of intermediate and high-grade. DCR and PFS were significantly better in patients with a Ki-67 index of ≤35% than in those with a Ki-67 index of >35%. On the basis of these results, PRRT should be considered as a therapeutic option in patients with high-grade SRI+ GEP-NENs, in particular those with a Ki-67 proliferation index of ≤35%

Feasibility and utility of re-treatment with 177Lu-DOTATATE in GEP-NENs relapsed after treatment with 90Y-DOTATOC

Purpose: Peptide receptor radionuclide therapy (PRRT) is a valid therapy for grade 1/2 gastroenteropancreatic (GEP) neuroendocrine neoplasms (NENs). Although a median progression-free survival (PFS) of more than 20 months is frequently observed, the majority of patients relapse after 2 â\u80\u93 3 years. In the present study, we investigated the use of low dosage re-treatment with 177Lu-DOTATATE (Lu-PRRT) in patients with GEP-NENs who relapsed after treatment with 90Y-DOTATOC (Y-PRRT). Methods: Upon tumour progression, 26 patients with a PFS of at least 12 months after Y-PRRT were consecutively enrolled in a phase II study of re-treatment with Lu-PRRT. All patients had preserved kidney and haematological parameters and received 14.8 â\u80\u93 18.5 GBq of Lu-PRRT in four or five cycles. The disease control rate (DCR), toxicity, PFS and prognostic factors were evaluated. Results: Median total activity of Lu-PRRT was 16.5 GBq in five cycles. The DCR was 84.6 %, median PFS was 22 months (95 % CI 16 months â\u80\u93 not reached) compared to 28 months (95 % CI 20 â\u80\u93 36 months) after Y-PRRT. Tumour burden and number of liver metastases were important prognostic factors. Toxicity was mild after Lu-PRRT re-treatment in the majority of patients, with only two patients with grade 2 and one with grade 3 bone marrow toxicity; one patient had grade 2 and one grade 3 renal toxicity. Conclusion: Patients with GEP-NEN who have previously responded to Y-PRRT are suitable candidates for Lu-PRRT re-treatment on progression. Although our sample size was limited, low-dosage Lu-PRRT was safe, and led to DCR and PFS rates comparable with those observed when Y-PRRT was used as primary treatment

Long-term follow-up and role of FDG PET in advanced pancreatic neuroendocrine patients treated with 177Lu-D OTATATE

Purpose: Lu-DOTATATE (Lu-PRRT) is a valid therapeutic option in differentiated pancreatic neuroendocrine tumors (P-NETs). FDG PET seems to be an important prognostic factor in P-NETs. We evaluated the efficacy of Lu-PRRT and the role of FDG PET in 60 patients with advanced P-NETs. Methods: From March 2008 to June 2011, 60 consecutive patients with P-NETs were enrolled in the study. Follow-up lasted until March 2016. Eligible patients were treated with two different total cumulative activities (18.5 or 27.8 GBq in 5 cycles every 6â\u80\u938 weeks), according to kidney and bone marrow parameters. Results: Twenty-eight patients received a mean full activity (FA) of 25.9 GBq and 32 a mean reduced activity (RA) of 18.5 GBq. The disease control rate (DCR), defined as the sum of CR+PR+SD was 85.7 % in the FA group and 78.1 % in the RA group. Median progression-free survival (mPFS) was 53.4 months in the FA group and 21.7 months in the RA group (P = 0.353). Median overall survival (mOS) was not reached (nr) in FA patients and was 63.8 months in the RA group (P = 0.007). Fifty-five patients underwent an FDG PET scan before Lu-PRRT, 32 (58 %) showing an increased FDG uptake in tumor sites. mPFS was 21.1 months in FDG PET-positive patients and 68.7 months in the FDG PET-negative group (P < 0.0002), regardless of the total activity administered. Conclusion: Both FA and RA are active in patients undergoing Lu-PRRT. However, an FA of 27.8 GBq of Lu-PRRT prolongs PFS and OS compared to an RA of 18.5 GBq. Our results indicate that FDG PET is an independent prognostic factor in this patient setting

Peptide receptor radionuclide therapy with 177Lu-DOTATATE in advanced bronchial carcinoids: prognostic role of thyroid transcription factor 1 and 18F-FDG PET

Purpose: Typical and atypical carcinoids (TC and AC) represent 20 â\u80\u93 25 % of all neuroendocrine tumours. No standard therapeutic approach is available for patients with advanced disease. The aim of this phase II study was to investigate the efficacy and safety of peptide receptor radionuclide therapy with 177Lu-DOTATATE (Lu-PRRT) and the role of thyroid transcription factor 1 (TTF-1) and 18F-FDG PET as prognostic factors in patients with advanced TC or AC. Methods: A total of 34 consecutive patients with radiologically documented progressive disease were treated with Lu-PRRT at a therapeutic cumulative activity of 18.5 or 27.8 GBq in four or five cycles according to the patientâ\u80\u99s kidney function and bone marrow reserve. Information on TTF-1 was available in all patients. FDG PET studies prior to Lu-PRRT were available in 29 patients. Results: The median follow-up was 29 months (range 7 â\u80\u93 69 months). The disease control rate (DCR) in patients with TC was 80 %: 6 % complete response, 27 % partial response and 47 % stable disease. The median progression-free survival (mPFS) was 20.1 months (95 % CI 11.8 â\u80\u93 26.8 months). Stable disease was achieved in 47 % of patients with AC with a mPFS of 15.7 months (95 % CI 10.6 â\u80\u93 25.9 months). No major acute or delayed toxicity occurred in either group or with either cumulative activity. mPFS in patients with TTF-1-negative TC was 26.3 months (95 % CI 12.9 â\u80\u93 45.2 months), but in patients with TTF-1-positive TC mPFS was 7.2 months (4.2 â\u80\u93 14.0 months; p = 0.0009). FDG PET was negative in 13 patients (10 TC and 3 AC) and positive in 16 patients (4 TC and 12 AC). The mPFS in the FDG PET-negative group was 26.4 months (95 % CI 14.2 â\u80\u93 48.9 months) and 15.3 months (11.7 â\u80\u93 31.1 months) in the FDG PET-positive group. Conclusion: Lu-PRRT showed antitumour activity in terms of DCR and PFS and proved safe, even in patients with a higher risk of side effects. TTF-1 would appear to be a prognostic factor. FDG PET positivity in bronchial carcinoids is a hallmark of aggressive tumour and is more frequent in patients with AC than in those with TC