A combination of capecitabine-temozolomide chemotherapy and 177Lu-DOTATATE peptide receptor radionuclide therapy successfully controlled life-threatening hypoglycemia and shrank tumors in a patient with recurrent metastatic insulinoma that had resisted multiple prior treatments.
Tumor shrinkage sustained at 8 monthsAfter failing four prior treatment regimens including sunitinib, everolimus, lanreotide, and streptozocin-based chemotherapy, the CAPTEM plus PRRT combination achieved ongoing anti-tumor response
What the researchers found
The combination of capecitabine plus temozolomide (CAPTEM) and 177Lu-DOTATATE peptide receptor radionuclide therapy (PRRT) achieved both symptom control and tumor shrinkage in a patient with heavily pretreated metastatic insulinoma. The patient had previously failed sunitinib, everolimus, lanreotide, and streptozocin plus 5-fluorouracil.
After starting the combined regimen, the frequency of hypoglycemic attacks decreased sufficiently to eliminate the need for daily intravenous glucose infusions, allowing hospital discharge on day 58. CT imaging at 8 months confirmed ongoing shrinkage of both the primary pancreatic tumor and metastatic lesions, with no major adverse events reported.
Why it matters
Insulinomas that recur after surgery and resist multiple drug therapies represent a serious clinical challenge, as the uncontrolled insulin secretion can cause life-threatening hypoglycemia. 177Lu-DOTATATE (marketed as Lutathera) is a peptide-based therapy that uses a somatostatin analog to target and deliver radiation directly to neuroendocrine tumor cells. This case demonstrates that even when many standard options have failed, combining PRRT with chemotherapy may offer meaningful disease control — highlighting the growing role of peptide-targeted therapies in hard-to-treat cancers.
How the study worked
This is a single-patient case report. The patient received CAPTEM chemotherapy followed by 177Lu-DOTATATE PRRT. Treatment response was monitored through clinical assessment of hypoglycemic attack frequency, need for glucose infusions, and CT imaging to evaluate tumor size changes over an 8-month follow-up period.
What this study cannot tell us
As a single case report, the findings cannot be generalized — what worked for this one patient may not work for others with insulinoma. There was no control group or comparison arm. The 8-month follow-up is relatively short for assessing long-term cancer outcomes. It is unclear whether the benefit came primarily from CAPTEM, PRRT, or specifically their combination. The somatostatin receptor status of the tumor was not detailed in the abstract.
How to read the evidence
This is a single case report — the lowest level of clinical evidence. While the outcome is encouraging, case reports cannot establish causation or generalizability. They are most useful for generating hypotheses and documenting unusual treatment responses that may warrant further study.
When this study was published
Published in 2023, this is a recent case report reflecting current treatment options for neuroendocrine tumors, including FDA-approved 177Lu-DOTATATE (Lutathera).
The bigger picture
177Lu-DOTATATE (Lutathera) was FDA-approved in 2018 for gastroenteropancreatic neuroendocrine tumors based on the landmark NETTER-1 trial. However, insulinomas — which are often negative for the somatostatin receptors that DOTATATE targets — have been less studied with PRRT. This case adds to the limited but growing evidence that some insulinomas do express sufficient somatostatin receptors to benefit from peptide-targeted radiation, especially when combined with sensitizing chemotherapy. It reflects a broader trend toward personalized, molecularly targeted treatment in rare cancers.
Questions still open
- Would 177Lu-DOTATATE PRRT alone have been sufficient, or was the chemotherapy combination essential for this response?
- What proportion of recurrent insulinomas express enough somatostatin receptors to be candidates for PRRT?
- How long can the tumor response and glycemic control be maintained with continued CAPTEM plus PRRT treatment?
Common questions
What is peptide receptor radionuclide therapy (PRRT) and how does it work?
What is an insulinoma and why is it dangerous?
Read the original research
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.
Clinical journal of gastroenterology, 16(5), 767-771
Citation
Terashima, Takeshi; Yamashita, Tatsuya; Takemura, Naoki; Inaki, Anri; Shimizu, Akinori; Harada, Kenichi; Yamashita, Taro; Kinuya, Seigo; Hanada, Keiji. (2023). 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.. Clinical journal of gastroenterology, 16(5), 767-771. https://doi.org/10.1007/s12328-023-01824-8