Metastatic Insulinoma Pancreatic Neuroendocrine Tumor Treated With 177Lu-DOTATATE Induction and Maintenance Peptide Receptor Radionuclide Therapy: A Suggested Protocol.

A 70-year-old woman presented with frequent episodes of hypoglycemia. Imaging revealed a 6-cm pancreatic mass with several liver lesions. The pancreatic mass was resected and confirmed to be a well-differentiated insulinoma. Surgery improved but did not resolve her hypoglycemic episodes, and she was referred for peptide receptor radionuclide therapy with 177Lu-DOTATATE to treat her residual disease. A modified protocol with a continuous IV dextrose infusion was used, and the treatments were well tolerated. After 4 induction and 2 maintenance treatments, her hypoglycemic symptoms resolved completely and her disease stabilized. She has been progression free for 24 months.

Orbital Metastases of Neuroendocrine Tumors Treated With 177Lu-DOTATATE PRRT or 131I-MIBG Therapies.

Neuroendocrine tumors have a propensity to metastasize to the orbit, although the reason is unknown. A review of 251 neuroendocrine tumors treated with Lu-DOTATATE or I-MIBG at our institution since 2003 revealed 4 patients with orbital metastases (1.6%), 2 treated with Lu-DOTATATE and 2 with I-MIBG. Of these 4 patients, 1 patient was symptomatic with diplopia and eye pain, and 2 patients had physical signs of orbital involvement. The symptomatic orbital metastasis improved with Lu-DOTATATE therapy, and proptosis improved with I-MIBG therapy in 1 of 2 patients. We present the imaging findings of these 4 patients, as well as their management.

Palliation of Extensive Metastatic Bone Disease With 223Ra-Dichloride α-Particle Therapy in a Patient With Malignant Hereditary Paraganglioma-Pheochromocytoma Syndrome With SDHB Mutation.

A 26-year-old woman with a 5-year history of metastatic paraganglioma due to hereditary paraganglioma-pheochromocytoma syndrome with SDHB mutation, who had failed multiple treatment regimens and had transfusion dependent pancytopenia, presented with progressive liver and bone metastases. She was unable to sleep due to painful skull metastases and had severe weakness in her extremities that limited her mobility and daily activities. She was treated with 2 doses of Ra-dichloride (Xofigo, Ra) and had a dramatic improvement in pain control, mobility, and overall quality of life for 8 weeks, before passing away from pulmonary hemorrhage.

Combined Treatment With 131I-MIBG and Sunitinib Induces Remission in a Patient With Metastatic Paraganglioma Due to Hereditary Paraganglioma-Pheochromocytoma Syndrome From an SDHB Mutation.

A 22-year-old woman with rapidly progressing metastatic paraganglioma due to hereditary paraganglioma-pheochromocytoma syndrome from an SDHB mutation, who recurred after neoadjuvant chemotherapy, was found to be MIBG avid. She was treated with 2 I-MIBG treatments and concurrent sunitinib, achieving a complete response. She was in full remission for 9 months before developing bone metastases.

Ectopic Corticotropin-Producing Neuroendocrine Tumor of the Pancreas Treated With 177Lu DOTATATE Induction and Maintenance Peptide Receptor Radionuclide Therapy.

A 57-year-old woman diagnosed with ectopic Cushing syndrome was found to have a 111In-octreotide-avid corticotropin-producing pancreatic neuroendocrine tumor with liver metastases. She was treated with 4 induction and 4 maintenance cycles of 177Lu-DOTATATE, which normalized her serum corticotropin levels and dramatically reduced the size of the pancreatic primary and liver metastases.

The Challenges of Treating Paraganglioma Patients with (177)Lu-DOTATATE PRRT: Catecholamine Crises, Tumor Lysis Syndrome and the Need for Modification of Treatment Protocols.

PURPOSE: A high percentage of paragangliomas express somatostatin receptors that can be utilized for targeted radioisotope therapy. The aim of this study was to describe and discuss the challenges of treating these tumors with (177)Lu-[DOTA(0),Tyr(3)]octreotate (DOTATATE) radioisotope therapy using established protocols. METHODS AND RESULTS: Three paraganglioma patients were treated with 4-5 cycles of (177)Lu-DOTATATE and were evaluated for side effects and response to therapy. Two of the three patients developed severe adverse reactions following their first (177)Lu-DOTATATE treatment. One patient developed a catecholamine crisis and tumor lysis syndrome within hours of treatment, requiring intensive care unit (ICU) support, and another developed a catecholamine crisis 3 days after treatment, requiring hospitalization. The treatment protocols at our institution were subsequently modified by increasing the radioisotope infusion time from 15 to 30 min, as recommended in the literature, to 2-4 h and by reducing the administered dose of (177)Lu-DOTATATE. Subsequent (177)Lu-DOTATATE treatments utilizing the modified protocols were well tolerated, and response to therapy was achieved in all three patients, resulting in significantly improved quality of life. CONCLUSION: (177)Lu-DOTATATE is an exciting new therapeutic option in the management of paragangliomas; however, current treatment protocols described in the literature may need to be modified by lengthening the infusion time and/or lowering the initial treatment dose to prevent or reduce the severity of adverse reactions.

Esthesioneuroblastoma (olfactory neuroblastoma) treated with 111In-octreotide and 177Lu-DOTATATE PRRT.

A 51-year-old man with a recurrent metastatic esthesioneuroblastoma (olfactory neuroblastoma) was referred for peptide receptor radionuclide therapy (PRRT). He received 4 treatments of 111In-octreotide over 8 months and 3 treatments of 177Lu-DOTATATE over 4 months, which helped alleviate his symptoms and improved his quality of life; however, the tumor ultimately progressed and he passed away shortly thereafter. PRRT with 111In-octreotide or 177Lu-DOTATATE could play a role in the management of esthesioneuroblastoma.

Medullary thyroid carcinoma (MTC) treated with 177Lu-DOTATATE PRRT: a report of two cases.

Two patients diagnosed with metastatic medullary thyroid carcinoma (MTC) were referred for peptide receptor radionuclide therapy (PRRT) with Lu-[DOTA,Tyr]octreotate (DOTATATE). Each patient was treated with 4 doses of Lu-DOTATATE given 2 months apart. One patient achieved stable disease for 10 months then chose to pursue surgery, and the other achieved stable disease for 9 months on imaging; however, calcitonin continued to rise. The use of Lu-DOTATATE PRRT therapy in the management of MTC warrants further research.

Incidental Acinic Cell Carcinoma of the Parotid Gland Discordant on 123I-MIBG, 111In-Octreotide, and 18F-FDG PET/CT in a Patient With Neuroendocrine Tumor of the Cecum.

A 61-year-old woman diagnosed with a metastatic well-differentiated neuroendocrine tumor of the cecum was referred for radioisotope therapy. Although her metastatic neuroendocrine tumor was positive on both (123)I-MIBG and (111)In-octreotide, there was a left parotid mass that was octreotide avid but MIBG negative. Further investigation also showed discordance on (18)F-FDG PET/CT and excision of the mass revealed an incidental acinic cell carcinoma of the parotid gland. Somatostatin analog imaging and PRRT (peptide receptor radionuclide therapy) may have a role in the management of acinic cell carcinoma.

Thymoma treated with 177Lu DOTATATE induction and maintenance PRRT.

A 47-year-old man presented with a recurrent thymoma World Health Organization type A of the anterior chest wall with pleural metastases after failing chemotherapy. The tumor was positive on In-octreotide, and he was referred for peptide receptor radionuclide therapy (PRRT) with Lu DOTATATE. He received 4 induction and 2 maintenance Lu DOTATATE treatments (total dose, 1000 mCi) and reported significant improvement in symptoms. Before the seventh treatment, mild progression was diagnosed on CT, and PRRT was terminated. The use of induction and maintenance Lu DOTATATE PRRT therapy in the management of thymoma warrants further research.

Extraventricular neurocytoma treated with 177Lu DOTATATE PRRT induction and maintenance therapies.

A 64-year-old woman with a 30-year history of recurrent sellar masses presented with severe headache and rapidly progressive visual field loss in the left eye. She was diagnosed with an extraventricular neurocytoma, which was octreotide positive, and was referred for PRRT (peptide receptor radionuclide therapy) with 177Lu [DOTA0,Tyr3]octreotate (DOTATATE). After 4 induction and 4 maintenance treatment cycles, her headaches resolved, her vision improved, and her sellar mass stabilized. The use of 177Lu DOTATATE PRRT in the management of extraventricular neurocytoma warrants further research.

Rhabdoid papillary meningioma treated with 177Lu DOTATATE PRRT.

An 18-year-old girl presented with a 3-year history of a recurrent skull base mass confirmed to be a rhabdoid papillary meningioma. The tumor was octreotide avid and metastatic to the lungs, thoracic lymph nodes, and bones, and she was referred for PRRT (peptide receptor radionuclide therapy) with 177Lu DOTATATE. After 3 induction treatment cycles of 177Lu DOTATATE, she experienced significant improvements in her symptoms; however, just before the fourth treatment, she developed cervical spinal cord compression and passed away shortly thereafter. The use of 177Lu DOTATATE therapy in the management of rhabdoid papillary meningioma warrants further research.

Cardiac metastases of neuroendocrine tumors treated with 177Lu DOTATATE peptide receptor radionuclide therapy or 131I-MIBG therapy.

Neuroendocrine tumors have a propensity to metastasize to the heart, although the reason for this remains unknown. A review of 251 neuroendocrine tumor patients treated with Lu DOTATATE peptide receptor radionuclide therapy or I-MIBG therapy at our institution since 2003 revealed 2 patients with cardiac metastases (incidence, 0.8%), one treated with Lu DOTATATE and one with I-MIBG. We present the imaging findings of these 2 patients, as well as their management and responses to therapy.

Resolution of Hyperreninemia, Secondary Hyperaldosteronism, and Hypokalemia With 177Lu-DOTATATE Induction and Maintenance Peptide Receptor Radionuclide Therapy in a Patient With Pancreatic Neuroendocrine Tumor.

A 54-year-old woman presented with a history of nausea, vomiting, diarrhea, and recurrent episodes of severe hypokalemia requiring hospitalization. Imaging revealed a pancreatic mass with liver metastases, histologically confirmed to be a neuroendocrine tumor. Elevated active renin and aldosterone levels were identified, and the patient was treated with 4 induction cycles of Lu-DOTATATE, which resolved the diarrhea, nausea, and hypokalemia, and normalized the renin and aldosterone levels. After 3 additional maintenance Lu-DOTATATE treatments, the pancreatic tumor had decreased in size, was deemed operable, and was resected. She remains on maintenance Lu-DOTATATE therapy with progression-free survival of 45 months thus far.

Liver and bone metastases from small bowel neuroendocrine tumor respond to 177Lu-DOTATATE induction and maintenance therapies.

A 73-year-old man diagnosed with small bowel neuroendocrine tumor (NET) with liver and bone metastases was treated with 4 induction cycles and 2 maintenance cycles of Lu-DOTATATE peptide receptor radionuclide therapy (PRRT). His symptoms and mobility improved significantly following induction as well as maintenance treatments, and posttherapy imaging studies showed significant improvement in metastatic liver and bone disease. Current protocols consisting of 4 induction cycles of Lu-DOTATATE only may not be sufficient to optimally treat neuroendocrine liver and bone metastases, and further research into maintenance Lu-DOTATATE therapy is warranted.

Glucagonoma Pancreatic Neuroendocrine Tumor Treated With 177Lu DOTATATE Induction and Maintenance Peptide Receptor Radionuclide Therapy.

A 56-year-old man presented with a history of 2 prior resections of a recurrent pancreatic glucagonoma in the past 4 years. Workup revealed new liver and abdominal nodal metastases with a rising serum glucagon level. He was started on peptide receptor radionuclide therapy with Lu DOTATATE, and his disease stabilized, while his glucagon levels decreased and also stabilized. After 4 induction and 2 maintenance cycles, he remains progression free for 23 months.

Resolution of Malignant Ascites and Stabilization of Metastases in a Patient With Small Bowel Neuroendocrine Tumor With 177Lu-DOTATATE Following Progression After 17 131I-MIBG Treatments and Chemotherapy.

A 39-year-old man diagnosed with a small bowel neuroendocrine tumor metastatic to the liver, lymph nodes, and bones achieved stable disease with ¹³¹I-MIBG therapy totalling 17 treatments over 9 years (cumulative dose of 1.9 Ci). His disease progressed after the 17th ¹³¹I-MIBG treatment, and he went on to fail chemotherapy, developing severe ascites requiring up to 8 L of weekly paracentesis. He was referred for ¹77Lu-[DOTA°,Tyr³]octreotate (DOTATATE) therapy, and after 4 induction cycles, his ascites resolved completely, and his metastatic disease stabilized. ¹77Lu-DOTATATE may be useful in patients with an extensive history of radioisotope therapy with ¹³¹I-MIBG.

Complete Resolution of Neuroendocrine Tumor Soft Tissue Metastases After 177Lu DOTATATE PRRT Induction and Maintenance Therapy.

A 60-year-old woman diagnosed with a well-differentiated neuroendocrine tumor metastatic to the liver and lymph nodes was treated with 4 induction cycles and 2 maintenance cycles of (177)Lu [DOTA,(0)Tyr(3)]octreotate (DOTATATE) peptide receptor radionuclide therapy. Her posttreatment imaging showed partial response after 4 induction cycles and complete response after 2 additional maintenance cycles. This case highlights the need for further research into maintenance (177)Lu DOTATATE therapy to improve outcomes in neuroendocrine tumor patients.