Safety and response after peptide receptor radionuclide therapy with 177 Lu-DOTATATE for neuroendocrine tumors in phase 1/2 prospective Japanese trial

Maximum tumor diameter and renal function can predict the declining surface dose rate after 177Lu-Dotatate: preliminary results of single institution in Japan

PURPOSE

This study aimed to develop a user-friendly prediction formula for dose rate adjustment after initial 177Lu-Dotatate therapy from a prospective observational study of patients.

MATERIALS AND METHODS

This study included consenting patients in a prospective observational study who underwent their first treatment in four cycles of 177Lu-Dotatate treatment at our hospital between January 2022 and February 2024. All patients received 7.4 GBq of 177Lu-Dotatate. The prediction formula was derived from the regression analysis of tumor-related factors and renal function. Creatinine clearance was estimated using the Cockcroft-Gault equation in this study for renal function.

RESULTS

Among the 13 patients (seven males, six females, median age: 59 years), logarithmically transformed total tumor volume (cc) and maximum tumor diameter (mm) of primary tumors or metastases showed strong correlations (p < 0.001, R2 = 0.897). As such, the maximum tumor diameter was used as the tumor parameter in the prediction formula. Additionally, maximum tumor diameter and creatinine clearance showed strong (p < 0.001, R2 = 0.768) and moderate (p = 0.013, R2 = 445) correlations, respectively, with the ratio of the dose rate 5.5-h post-administration to the dose rate immediately post-administration (%) at 1 m from the body surface. The resulting formula, 51.4 + 0.360 × maximum tumor diameter (mm) - 0.212 × creatinine clearance (ml/min), demonstrated an extremely strong correlation (p < 0.001, R2 = 0.937).

CONCLUSION

The present study showed that the maximum tumor diameter and renal function affected the declining the dose rate of patients surface after 177Lu-Dotatate, which can inform post-administration dose rate management and potentially facilitate outpatient treatment in Japan.

Multimodal management of foregut neuroendocrine neoplasms

The foregut, which includes the esophagus, stomach and duodenum, represents one of the most common sites for neuroendocrine neoplasms. These are highly heterogenous with different risk of progression depending on location, cell-type of origin, size, grade and other factors. Various endoscopic and imaging modalities exist to inform therapeutic decision-making, which may be in the form of surgical or endoscopic resection and medical therapy depending on the extent of the disease after diagnostic evaluation. This narrative review aims to explore the literature on the multimodal management of such foregut neuroendocrine neoplasms.

A case of frequent hypoglycemic attacks successfully controlled with capecitabine plus temozolomide and 177Lu-DOTATATE peptide receptor radionuclide therapy in a patient with recurrent pancreatic insulinoma

A 59-year-old woman with metastatic pancreatic insulinoma, having undergone several treatment regimens including sunitinib, everolimus, lanreotide and streptozocin plus 5-fluorouracil, was admitted to our hospital because of frequent hypoglycemic attacks. These were refractory to medical treatment using diazoxide and required frequent daily intravenous glucose infusions. She was started on capecitabine and temozolomide (CAPTEM), followed by initiation of 177Lu-DOTATATE peptide receptor radionuclide therapy (PRRT). The frequency of hypoglycemic attacks decreased after treatment began and she was discharged on day 58 post-admission, without requiring daily glucose infusions. CAPTEM and PRRT were continued without any major adverse events. Computed tomography revealed shrinkage of primary and metastatic lesions, an anti-tumor effect that continued 8 months after treatment was initiated. Hypoglycemic attacks caused by insulinomas are often refractory to conventional therapy; however, combination treatment using CAPTEM and PRRT has demonstrated a positive and significant response, successfully restoring glycemic control.

Gastro-Enteric-Pancreatic Neuroendocrine Tumor Treatment: 177Lu-DOTATATE

177Lu-DOTA-TATE therapy is a highly effective therapy in metastatic, well-differentiated, somatostatin receptor-positive GEP-neuroendocrine tumors (NETs) with mostly tolerable adverse effects. Guidelines generally refer to peptide receptor radionuclide therapy as a second-line therapy after SSA in gastroenteric and second- or third-line therapy in pancreatic NETs to improve survival rates and quality of life. Although we do not have sufficient data, 177Lu-DOTA-TATE therapy may also have a role in high-grade NET therapy, mostly in combination with other treatments such as chemotherapy.

Efficacy and safety of 177Lu-DOTATATE targeted therapy in advanced/metastatic pulmonary neuroendocrine tumors: A systematic review and meta-analysis

Objective

To perform a meta-analysis of the efficacy and safety about ¹⁷⁷Lu-DOTATATE therapy for advanced/metastatic pNETs based on the current clinical evidence.

Methods

This systematic review follows the PRISMA guideline. Search PubMed, Medline, EMBASE and CNKI, VIP, Wanfang databases, from establishment to June 2022, on the study of ¹⁷⁷Lu-DOTATATE for advanced/metastatic pNETs, the primary endpoint was to evaluate the treatment effect through DRRs and DCRs. Secondary endpoint included assessment of OS, PFS, and treatment-related adverse events across all studies. Two researchers conducted literature screening, data extraction and quality evaluation according to the inclusion and exclusion criteria. Meta-analysis was performed using stata16.0 software, and the data were merged and displayed using forest graphs.

Results

A total of 5 studies, 174 patients, on ¹⁷⁷Lu-DOTATATE for advanced/metastatic pNETs were included. The pools of DRRs and DCRs were 24% (95% CI: 15%~32%) and 77% (95% CI: 62%~92%), respectively. The pool of OS was 48.78 months (95% CI: 41~56.57 months) and the pool of PFS was 21.59 months (95% CI: 17.65~25.53 months). In all studies, the most common side effect of treatment was hematological toxicity. In 174 patients, hematological toxicity of grade III accounted for 4.0% (7/174), and only 4.0% (7/174) and 1.0% (2/174) of patients had mild nephrotoxicity and hepatotoxicity. Gastrointestinal adverse reactions in 3% (6/174), nausea in 2% (3/174), superior vena cava occlusion in 0.5% (1/174).

Conclusion

¹⁷⁷Lu-DOTATATE is effective and safe for advanced/metastatic pNETs, which can delay the progression of the disease, may improve patients' survival, and has low treatment-related toxicity and high safety. However, its efficacy and safety need to be further evaluated in high-quality, multicenter randomized controlled trials in the future.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022344436.