Theranostics for neuroendocrine tumors: A patient’s experience ​

After receiving the diagnosis of neuroendocrine tumors, Glenda’s oncologist was unable to provide effective treatment options. Considering her disease burden and noting the progression of the tumors that were difficult to surgically remove, Glenda was referred for theranostics treatment. 

Photography by Maria Julie Borer | Data courtesy of Nebraska Cancer Specialists, Nebraska, USA

Glenda’s severe abdominal pain went undiagnosed and was then misdiagnosed for years before a CT scan revealed an abnormality, ultimately leading to a diagnosis of neuroendocrine tumors. After her cancer progressed despite treatment with a somatostatin agonist, she began a theranostic treatment that has turned a life-threatening disease into a chronic, manageable illness.

With her theranostic treatment complete, the 61-year-old credits her referring physician and clinical team at Nebraska Cancer Specialists (NCS), led by Samuel Mehr, MD, director of Nuclear Oncology, with providing her hope through personalized therapy and seamlessly coordinated care.

“On the last day of my treatment, Dr. Mehr told me that he has every reason to believe this is working beautifully for me, but if it doesn’t, there are lots of other things we can do,” Glenda says. “I have complete faith in them and feel like they were all put in my life for a reason.”

Theranostics is an innovative form of personalized therapy that focuses on both the accurate selection of patients and providing them with targeted radioligand therapy to improve their prognosis.¹ After considering her disease burden and noting the progression of tumors that were difficult to surgically remove, her oncologist referred her to NCS for theranostic treatment with ¹⁷⁷Lu-DOTATATE.

Theranostic treatment incorporates the use of targeted radioligands, imaging modalities such as PET/CT and SPECT/ CT, and laboratory diagnostics. The number of clinicians and steps required for a successful theranostic treatment necessitates a high degree of coordination, which is why NCS has a designated nurse case manager who supports patients receiving standard theranostic treatments as well as those enrolled in clinical trials.

As the theranostics nurse case manager and theranostics research nurse coordinator, Marlene Bridwell, RN, is the primary point of contact for patients and is responsible for coordinating clinical care within NCS and with the patients’ referring physicians and supplemental care providers.

With the patient’s consent, Bridwell is present for the initial physician consultation and all subsequent appointments. She orders tests, schedules exams and treatments, and is in regular contact with patients and other care providers. 

“In my role, I make sure patients get what they need when they need it prior to treatment, and then also throughout the course of their treatment,” Bridwell says. “I monitor lab values along with Dr. Mehr and am on the phone with patients quite a bit because I want them to be fully aware of what’s going on in their treatments. There’s no question that if they have any concerns, they can reach out to me.” 

NCS serves as a model theranostics program for the OnCare Alliance and the Exigent Research Network, and Mehr emphasizes the importance of having a designed nurse case manager for theranostics care. 

“Marlene’s role is critical for a seamless and successful theranostics program,” Mehr says. “Without someone doing what she does, treatments become chaotic for no other reason than poor communication.”

Mehr explains that for patients with neuroendocrine tumors, PET/CT is essential for assessing their likelihood of benefiting from theranostic treatment with ¹⁷⁷Lu-DOTATATE. “We look at the amount of the DOTATATE, which is the non-radioactive portion of the molecule, that accumulates in tumor sites,” Mehr says. “There’s a direct correlation between how much of the drug gets to tumor sites in the diagnostic scan and how much of the therapeutic drug will get there.” 

Prior to treatment, patients undergo bloodwork and other laboratory diagnostics, have ports placed, and undergo an echocardiogram to check for abnormalities of the tricuspid valve, which are not uncommon in patients with metastatic neuroendocrine disease. These abnormalities typically do not exclude a patient from eligibility for treatment, Mehr says, but the treatment team is expanded to include a cardiologist if abnormalities are present.

The drug is administered via infusion, typically once every eight weeks for a total of four treatments. The ¹⁷⁷Lu-DOTATATE is delivered over approximately 45 minutes and is preceded by the administration of anti-nausea medication and an infusion of amino acids to protect the kidneys. The entire infusion process lasts approximately six hours. 

The day following their treatment, patients receive intravenous fluids to help flush the kidneys. Between treatments, patients undergo laboratory diagnostics to ensure that their blood cell counts remain within an acceptable level. Glenda also received injections of a somatostatin analogue 4 to 24 hours post theranostics treatment. 

Glenda was driven by family members to her appointments, and she slept and read during her theranostic treatments. Side effects are typically mild and include the transient suppression of bone marrow, which reduces blood cell counts. Glenda recalls that her side effects were minimal, with the most common being fatigue. 

“I didn’t have any severe side effects at all,” Glenda says, adding that she was able to continue working without taking an extended leave throughout her treatment. “I always did my treatment on a Friday, so that I would take fewer days off. I only had to take the Friday and the Monday off and could be back to work by Tuesday.” 

Bridwell added that many theranostics patients have previously undergone other treatments that can cause side effects that are much more difficult to manage than those associated with theranostic treatment. “The side effects of theranostic treatments are not nearly as harsh as expected,” Bridwell says. “I’ve had a lot of patients say to me, ‘I cannot believe how easy that was.'”

Mehr says that SPECT/CT for patients undergoing theranostic treatment for neuroendocrine tumors enables his team to document drug deposition to tumor sites. 

“It’s useful in patients who have a late, potentially life-threatening manifestation of their neuroendocrine tumor, and that’s liver failure due to hepatic metastases,” Mehr says. “In those cases, we feel comfortable in determining the quantity of drug that gets to the tumors. For other patients who don’t have concomitant illnesses or are in a less critical phase, we use the modality less frequently.” 

Mehr adds that CT is not routinely used for patients undergoing theranostic treatment for neuroendocrine tumors to avoid the risk of misinterpreting a phenomenon known as pseudo progression. He explains that tumor cells become inflamed in response to the radioactive drug before they die, and this inflammation makes tumors appear larger. 

“If you do a CT scan during that portion of the treatment, the tumors will appear to have grown, and many times that will be misinterpreted as a treatment failure,” he says. “If it’s misinterpreted that way, physicians will commonly stop a very successful course of treatment and deprive the patient of the benefits of that regimen.”

Severe abdominal pain forced Glenda to physician’s offices and emergency departments on and off for more than 15 years. Physicians couldn’t discern the cause of her pain, and she was eventually misdiagnosed with irritable bowel syndrome. 

Glenda points out that a common adage taught to medical students in the United States is “when you hear hoofbeats, think horses, not zebras,” meaning that doctors should consider common conditions before diagnosing patients with rare conditions. Since zebras do exist, the hoofbeats can indeed represent zebras on occasion. With an incidence rate of 6.98 per 100,000 people², neuroendocrine tumors are relatively rare in the United States. Glenda’s condition, in other words, is a zebra rather than a horse. 

Even with the correct diagnosis of neuroendocrine tumors, the oncologist she initially saw was unable to provide effective treatment options. “The very first oncologist I saw read me the diagnosis and told me ‘This is what you have, but I do not have the tools in my toolbox to treat you,’” she recalls. “That is a really upsetting thing to hear when you’ve been told that you have cancer.” 

She urges patients to seek out knowledgeable specialists and credits her referring physician and theranostic treatment providers at NCS with giving her hope for a future in which she can spend more time with her husband, children, grandchildren, and great grandchild.

Sameh Fahmy, MS, is an award-winning freelance medical and technology journalist based in Athens, Georgia, USA.