Metastatic Malignant Paraganglioma Presenting as a Neck Mass Treated with Radiolabeled Somatostatin Analog

Paragangliomas are rare neuroendocrine tumors that arise from chromaffin-containing tissue. Surgical resection and/or radiation are used for locoregional disease, and reduction of tumor burden with systemic therapy is reserved for metastatic disease. Iobenguane I-131, somatostatin analog (octreotide), and Sunitinib are noncytotoxic options for treatment, while cyclophosphamide, vincristine, and dacarbazine (CVD) and temozolomide are often used as initial chemotherapy options as studies have shown that they offer some tumor response. However, there are no randomized clinical trials demonstrating prolonged survival with the use of chemotherapeutics in metastatic cases. Investigation of alternative therapies that provide survival benefit is thus necessary. We present a case of a 69-year-old female with metastatic malignant paraganglioma presenting as a left parapharyngeal neck mass, which metastasized after surgery, requiring radiation therapy for bony metastasis who was treated with a radioisotope somatostatin analog for disease progression.

Targeted radiopeptide therapy Re188-P2045 to treat neuroendocrine lung cancer.

e20016 Background: : Despite the recent success of checkpoint inhibitors, there continues to be a significant medical need for lung cancer therapies that can be directed to the patients most likely to respond. Somatostatin receptor subtype 2 (SSTR2) is the most widely up-regulated subtype in both small and non-small cell lung cancers and is also expressed in tumoral (but not mature) blood vessels. Peptide targeted radiotherapy has advantages over traditional targeted therapies in that targeted tumor cells as well as surrounding cancer cells and supporting stroma are selectively killed. This study was conducted to determine the ability of Rhenium Re 188 P2045, a radiolabeled somatostatin analog specific for SSTR2 to both image (to select the most appropriate patients) and treat lung cancer patients who over-express somatostatin receptors. Methods: In an open label, single arm study, refractory lung cancer patients to standard of care therapy were identified by image analysis using Rhenium Re 188 P2045, a radiolabeled somatostatin analog. 25 Patients received the imaging dose of 10uCi of Re188 and 265ng of peptide by intravenous injection. Three patients were selected based on high SSTR expression levels to receive 30uCi of Re188 P2045 as a therapeutic dose 14 days after imaging. Patients were followed for 8 weeks post treatment. Results: The imaging study revealed a high density of expression of the somatostatin receptor in the lungs of patients. Patients in the imaging and therapeutic treatment groups reported no adverse advents or signs of toxicity. The image analysis using Re188 P2045 was compared to CT images and demonstrated accurate detection of lung tumor lesions. The images obtained using Re188 P2045 were of sufficiently high quality to enable identification of receptor expression at the tumor site as shown in Figures 1&2. Conclusions: Rhenium Re 188 P2045, a radiolabeled somatostatin analog, may be used to both identify and treat lung cancer tumors. The ability to image and dose patients with the same targeted molecule enables a personalized medicine approach and this highly targeted patient therapy may significantly improve treatment of tumors that over express somatostatin receptor.

Growth hormone–secreting macroadenoma of the pituitary gland successfully treated with the radiolabeled somatostatin analog 90Y-DOTATATE: case report

Pituitary tumors causing acromegaly are usually macroadenomas at the time of diagnosis, and they can grow aggressively, infiltrating surrounding tissues. Difficulty in achieving complete tumor removal at surgery can lead toward a strong tendency for recurrence, making it necessary to consider a means of treatment other than those currently used such as somatostatin analogs (SSAs), growth hormone (GH) receptor antagonist, surgical removal, and radiotherapy. The purpose of this paper is to describe a patient diagnosed with an aggressive, giant GH-secreting tumor refractory to medical therapy but ultimately treated with the radiolabeled somatostatin analog 90Y-DOTATATE. A 26-year-old male with an invasive macroadenoma of the pituitary gland (5.6 × 2.5 × 3.6 cm) and biochemically confirmed acromegaly underwent 2 partial tumor resections: the first used the transsphenoidal approach and the second used the transcranial method. The patient received SSAs pre- and postoperatively. Because of the progression in pituitary tumor size, he underwent classic irradiation of the tumor (50 Gy). One and a half years later, the patient presented with clinically and biochemically active disease, and the tumor size was still 52 mm in diameter (height). Two neurosurgeons disqualified him from further surgical procedures. After confirming the presence of somatostatin receptors in the pituitary tumor by using 68Ga-DOTATATE PET/CT, we treated the patient 4 times with an SSA bound with 90Y-DOTATATE. After this treatment, the patient attained partial biochemical remission and a reduction in the tumor mass for the first time. Treatment with an SSA bound with 90Y-DOTATATE may be a promising option for some aggressive GH-secreting pituitary adenomas when other methods have failed.

Metastatic Insulinoma Managed with Radiolabeled Somatostatin Analog

Insulinoma is a rare pancreatic neuroendocrine tumor. Overproduction of insulin and associated hypoglycemia are hallmark features of this disease. Diagnosis can be made through demonstration of hypoglycemia and elevated plasma levels of insulin or C-Peptide. Metastatic disease can be detected through computerized tomography (CT) scans, magnetic resonance imaging (MRI), and positron emission tomography (PET)/CT. Somatostatin receptor scintigraphy can be used not only to document metastatic disease but also as a predictive marker of the benefit from therapy with radiolabeled somatostatin analog. Unresectable metastatic insulinomas may present as a major therapeutic challenge for the treating physician. When feasible, resection is the mainstay of treatment. Prevention of hypoglycemia is a crucial goal of therapy for unresectable/metastatic tumors. Diazoxide, hydrochlorothiazide, glucagon, and intravenous glucose infusions have been used for glycemic control yielding temporary and inconsistent results. Sandostatin and its long-acting depot forms have occasionally been used in the treatment of Octreoscan-positive insulinomas. Herein, we report a case of metastatic insulinoma with very difficult glycemic control successfully treated with the radiolabeled somatostatin analog lutetium (177LU).