Neuroendocrine cancers are rare malignancies; however, their incidence is thought to be increasing. Such tumors are characterized by their overexpression of somatostatin receptors, present in up to 80% of cases. However, a novel radiopharmaceutical may give advanced practice RNs (APRNs) a new option to treat certain gastroenteropancreatic neuroendocrine tumors (GEP-NETs).
Lutetium Lu 177 dotatate, a peptide receptor radionuclide therapy (PRRT), was approved by the U.S. Food and Drug Administration in January 2018 to treat patients with GEP-NETs. Patients with inoperable or metastatic GEP-NETs must have a somatostatin receptor-positive status to be eligible for PRRT. Historically, those patients had very limited treatment options.
The phase III NETTER-1 trial demonstrated that lutetium Lu 177 dotatate in combination with long-acting somatostatin analog (SSA) significantly improved progression-free survival and led to higher response rate when compared with high-dose SSA alone. The treatment schedule consists of four lutetium Lu 177 dotatate infusions in eight-week intervals. SSAs are held for four weeks prior to infusion of PRRT; however short-acting SSAs can be used as needed for control of carcinoid syndrome symptoms. SSAs should be given the day after treatment as determined by the provider.
A potential rare acute complication is carcinoid crisis, which results from the release of an overwhelming amount of hormones.
Monitoring and Follow-Up
PRRT is generally well tolerated. Grade 3 or 4 neutropenia, thrombocytopenia, and lymphopenia occurred in 1%, 2%, and 9% of patients, respectively, in the NETTER-1 trial. Late hematologic effects, including delayed myeloid neoplasms, myelodysplastic syndrome (3%), and acute myeloid leukemia (3%) as well as renal failure (3%), are possible.
Because of the potential for nephrotoxicity, patients are given positively charged amino acid infusion (AA). However, delayed renal function impairment may still occur one to five years after PRRT. Kidney impairment may be more likely in patients with risk factors such as hypertension, diabetes, previous chemotherapy, or prior chemoembolization.
Although lutetium Lu 177 dotatate is given over 30 minutes, AA is infused over at least four hours. The AA determines the emetogenic potential, with lower osmolality solutions that contain two amino acids (arginine and lysine) being typically well tolerated. Antiemetics are given as premedications only if higher osmolality amino acid solutions are used. Antiemetics should be prescribed for home use as needed.
The risk of radiation emission and excretion is fairly low, but patients should be cautioned about good bathroom hygiene and to avoid contact with children, pregnant women, and crowds for one to three days after the therapy. They should also be encouraged to hydrate well to promote clearance of the radiopharmaceutical.
Post-treatment labs are sometimes used to look for electrolyte abnormalities. A potential rare acute complication is carcinoid crisis, which results from the release of an overwhelming amount of hormones. Symptoms include wide blood pressure fluctuations with a predominance of hypotension. SSA should be kept handy during any infusion to address it.
APRNs have a critical role in caring for patients receiving lutetium Lu 177 dotatate by increasing awareness, providing symptom management, monitoring for toxicity, and addressing acute and long-term toxicities. APRNs must become familiar with the management and toxicities of this newly approved therapy.