Therapeutic treatment using radiopharmaceutical I-131 mIBG can effectively mitigate symptoms of certain neuroendocrine tumors and improve prognosis for patients with symptomatic improvement, radiographic response or stability, and biochemical response.
The study, performed by scientists from Duke University and The University of North Carolina-Chapel Hill, was published online May 18 in the Journal of Nuclear Medicine.
“This suggests that despite previous recommendations, regular imaging, biochemical assay and clinical follow-up should be performed in patients with metastatic neuroendocrine tumors, particularly those undergoing I-131-mIBG treatment,” wrote corresponding author Salvador Borges-Neto, MD, with Duke University Medical Center’s department of radiology, and colleagues.
In this study, the group analyzed survival, symptoms, imaging and biochemical response data of 211 stage IV pulmonary and gastroenteropancreatic neuroendocrine tumor (P/GEP-NET) patients treated with mIBG between 1991 and 2014.
Some 71 percent of patients demonstrated symptomatic response with a 12-month median symptomatic relief time. Symptomatic response at first follow-up predicted a survival benefit of 30 months, according to the authors.
Additionally, biochemical response at first clinical follow up was seen in 34 percent of patients. Imaging response (20 percent of patients) or stability (60 percent) at three-month follow-up imaging extended a patient’s lifespan by 32 months.
Multiple mIBG treatments were associated with an additional 24 months of survival time, suggesting additional treatment may be more beneficial than a single session.
“Over the course of the disease, many patients with neuroendocrine tumors exhaust the standard options of somatostatin analogues, targeted therapies, and endovascular embolic techniques,” authors wrote. “I-131-mIBG may be of benefit in patients who fail these treatments or for patients whose tumors do not demonstrate the necessary scintigraphic uptake with radiolabeled somatostatin analogues.”
Borges-Neto suggested their results may lend proof that oncologists can utilize with patients for pre-treatment prognostic information and provide data for an individual’s response to treatment.