Dr. Luo Hui-Ling / Dr. Li Yue, Department of Nuclear Medicine
A Rare Cancer Threat: The Silent Danger of Neuroendocrine Tumors
Neuroendocrine tumors (NETs) are a rare type of cancer that originates from neuroendocrine cells. According to statistics from Taiwan’s Ministry of Health and Welfare, approximately 1,400 people in Taiwan are diagnosed with this condition each year. These tumors can develop in various organs throughout the body, most commonly in the digestive tract (stomach, colon, small intestine, pancreas) and lungs. Due to their hormone-secreting nature, NETs can cause hidden yet serious complications, such as gastrointestinal discomfort, metabolic dysfunction, and skin-related symptoms, significantly impacting patients' quality of life and, in severe cases, becoming life-threatening.
However, because the symptoms are often subtle or nonspecific, many patients fail to detect the disease in its early stages, missing the best opportunity for timely treatment.
Breakthrough in Diagnosis: Advanced PET Imaging Technology
Neuroendocrine tumors (NETs) differ from normal cells in that they express a high concentration of somatostatin receptors on their surface. With the rapid advancement of radiopharmaceuticals, positron emission tomography (PET) imaging using Ga-68-labeled somatostatin analogs (Ga-68-DOTATATE) has become a highly precise diagnostic tool specifically designed for NETs. This innovative imaging technique holds significant clinical value for early diagnosis and the detection of metastatic lesions.
Much like a reconnaissance aircraft, Ga-68-DOTATATE enables PET scans to clearly visualize the tumor’s location, size, and distribution, providing an accurate foundation for treatment planning and improving patient outcomes.
A Powerful Weapon Against Cancer: Multimodal Therapy Pushing the Limits
For neuroendocrine tumor (NET) treatment, localized tumors can often be cured through surgical removal. However, if the tumor has metastasized or reached an advanced stage, systemic therapies are required, including chemotherapy, targeted therapy, and radionuclide therapy. In recent years, breakthroughs in radiochemistry and drug research have led to the development of Lutetium-177 (Lu-177) targeted radionuclide therapy, an innovative anti-cancer technology. By combining the radioactive isotope Lu-177 with a targeting tracer, this therapy precisely attacks tumor cells while minimizing damage to healthy tissues.
The synergy between Ga-68 and Lu-177 DOTATATE exemplifies the core concept of nuclear medicine theranostics—seamlessly integrating diagnosis and treatment. This approach ensures precise tumor targeting, achieving a direct transition from “detecting lesions” to “eliminating lesions” in a single step. By complementing other treatment modalities, this diversified strategy offers new hope even for patients with advanced or complex NETs.
Clinical Breakthrough: Lu-177 Therapy Ushers in the Era of Precision Medicine
Lutetium-177 DOTATATE (Lu-177 DOTATATE) is a peptide receptor radionuclide therapy (PRRT) specifically designed for neuroendocrine tumors (NETs). By emitting beta particles (β rays), it destroys cancer cell DNA, preventing further division and proliferation, ensuring precise tumor eradication. Additionally, the gamma radiation (γ rays) emitted allows imaging to monitor tumor response and disease progression, providing critical data for treatment adjustments.
According to a 2017 study published in The New England Journal of Medicine, patients treated with Lu-177 DOTATATE had a 20-month progression-free survival (PFS) rate of 65.2%, significantly higher than the 10.8% in the untreated group. A 2024 study published in The Lancet further demonstrated that using Lu-177 DOTATATE as a first-line treatment for Grade 2 and Grade 3 advanced gastroenteropancreatic NETs extended progression-free survival by over 14 months in more than half of the cases.
With its outstanding efficacy and favorable safety profile, PRRT is rapidly surpassing traditional chemotherapy and radiotherapy, emerging as a revolutionary new weapon in the fight against neuroendocrine tumors.
Lu-177 Targeted Radionuclide Therapy: A New Frontier in Cancer Treatment
Lu-177 targeted radionuclide therapy must be conducted in a dedicated isotope therapy ward within the nuclear medicine department. The treatment process includes anti-nausea medication administration, intravenous infusion of renal protective agents, radiopharmaceutical injection, side effect monitoring, and post-treatment imaging, typically requiring half a day to complete.
The renal protective agent, an amino acid solution, is used to minimize kidney damage caused by radiation exposure. Since it may cause nausea and vomiting, anti-nausea medication is administered beforehand. As the drug is primarily excreted through the urinary system, patients are encouraged to drink plenty of water to accelerate its elimination.
Imaging scans are scheduled the day after treatment and one week later to assess tumor response and drug absorption. Potential side effects include bone marrow suppression, kidney function impairment, and hormonal crises. The medical team tailors personalized treatment plans, implements preventive measures, and closely monitors patients to reduce risks and enhance safety.
As nuclear medicine and precision oncology continue to evolve, Lu-177 targeted radionuclide therapy holds promise for treating additional cancer types, offering new hope and expanded treatment opportunities for cancer patients.