Foundations of theranostics
Radioligand therapy (RLT) and radioligand imaging (RLI) offer a novel, theranostic approach to targeting and treating certain types of cancer.1 This section of the Novartis RLT Institute is designed to help health care professionals (HCPs) understand the basic scientific foundations of RLT. By focusing on the science, we aim to demystify radiation and safety concerns and build confidence in offering patients this approach to precision medicine in cancer.
Radiation safety fundamentals
Waste management
Effective radiation waste management is a critical component of operating a facility that utilizes RLTs, ensuring both safety and regulatory compliance.2
Proper decontamination and waste disposal procedures are outlined in a center's radioactive material (RAM) license application to meet federal and state regulations. These regulations align with ALARA (as low as reasonably achievable) principles, minimizing exposure to ionizing radiation and maintaining safety standards.2,3
Collection
Radioactive waste materials must be identified by surveying all items to confirm if they are contaminated4
Separation
Separate collection bags (solids) and waste bins (liquids) for radionuclides with different physical half-lifes. This enables efficiency in trash disposal4
Labeling and organizationBased on guidance from the Nuclear Regulatory Commission, there are a number of organization and labeling requirements for waste management:
- Clear labeling: Each storage container should have clear labels indicating the isotope, activity level, the initial date of storage, and the “decay by” date5
- Isotope-specific storage: Isotopes should be separated in storage to accurately manage timelines2,6
- Decay period organization: Materials should be separated by date to accurately track decay periods for each item6
Expert insight
Planning ahead and strategically separating waste in batches enable RLT programs to efficiently rotate trash based on volume for the practice.7
Storage
Store all radioactive waste in the designated decay area until radiation returns to background levels (ie, normal limits), as confirmed by surveying. Waste can then be disposed of as regular waste, medical waste, or biohazardous waste, as appropriate and according to local, federal, and institutional guidelines2,8
Most radionuclides used for imaging and therapy in a clinical setting are considered low level waste, thus can decay in storage.6
Expert insight
A decay period of 10 physical half-lifes may be a helpful benchmark for materials to return to background levels.7 The physical half-life for 177Lu is 6.7 days, so survey materials after 67 days to confirm if materials have returned to background levels and are ready for disposal.7,9
Special considerations based on 177Lu preparation
Lutetium 177 (177Lu) may be prepared using 2 different sources of stable isotopes that may require different waste management procedures.10,11
Non–carrier-added method
Indirect irradiation of 176Yb is known as the "non–carrier-added" method.3,10
Carrier-added method
177Lu produced through direct irradiation of 176Lu is considered the "carrier-added" method.3,12
RLTs prepared with the carrier-added method may contain an intrinsic contaminant, lutetium 177Lu metastable (177mLu), which has a half-life of 160.4 days and cannot be decayed in storage without special considerations and/or permitting.12,13 As the transportation of all RAM must be managed by the US Department of Transportation, an outside vendor service may be required to help pick up and dispose of RLTs prepared using the carrier-added method.14
When using PLUVICTO® (lutetium Lu 177 vipivotide tetraxetan) and LUTATHERA® (lutetium Lu 177 dotatate), please consult the certificate of analysis (batch release) to identify the source of stable isotopes used and apply the appropriate waste management procedure.10,11
Contact the Novartis radioligand therapy specialists for support, including information on waste disposal services.