2022 AAPM 64th Annual Meeting
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Session Title: Radiobiology Issues Regarding Theranostic Radiopharmaceuticals
Question 1: The Biological Effective Dose BED-effect correlation curves derived for 90Y-peptides
Reference:Wessels BW, Konijnenberg MW, Dale RG, et al. MIRD pamphlet No. 20: the effect of model assumptions on kidney dosimetry and response--implications for radionuclide therapy. J Nucl Med. 2008 Nov;49(11):1884-99. doi: 10.2967/jnumed.108.053173. PMID: 18927342
Choice A:Can be directly used for 177Lu-peptides, i.e., for a same mean BED value in the organ of interest derived for 90Y or 177Lu, the effect has the same probability to occur
Choice B:Are not yet verified to directly apply to 177Lu-peptides, for a same mean BED value in the organ of interest; they might be influenced by the different physical half-life of the two radionuclides
Choice C:Are not yet verified to directly apply to 177Lu-peptide, for a same mean BED value in the organ of interest: they might be influenced by the different range of the beta particles emitted by the two radionuclides
Choice D:Overlap the absorbed dose correlation curves derived for 177Lu-peptides
Question 2: The dose-effect thresholds derived in the Radioembolization of liver lesions by 90Y microspheres
Reference:Cremonesi M, Chiesa C, Strigari L, et al. Radioembolization of hepatic lesions from a radiobiology and dosimetric perspective. Front Oncol. 2014 Aug 19;4:210. doi: 10.3389/fonc.2014.00210. PMID: 25191640
Choice A:Are, in general, very similar for both, resin and glass 90Y-microspheres
Choice B:Are, in general, much lower for resin as compared to glass 90Y-microspheres, due to a higher radiation uniformity, related to the higher number of microspheres injected for a same injected activity loading
Choice C:Are, in general, much higher for resin as compared to glass 90Y-microspheres, due to the much lower diameter of the resin microspheres
Choice D:Depend only on the absorbed dose, being not influenced by other radiobiological issues
Question 3: All of the following factors influence the in vivo targeting properties of RPT agents except
Reference:Holliger P, Hudson PJ. Engineered antibody fragments and the rise of single domains. Nat Biotechnol. 2005 Sep;23(9):1126-36. doi: 10.1038/nbt1142. PMID: 16151406
Choice A:Blood circulation half-life
Choice B:Binding affinity for its target
Choice C:Radionuclide half-life
Choice D:Molecular weight
Question 4: In general, using albumin binders in RPT agents
Reference:Zorzi A, Linciano S, Angelini A. Non-covalent albumin-binding ligands for extending the circulating half-life of small biotherapeutics. Medchemcomm. 2019;10(7):1068-1081. Published 2019 Jun 6. doi:10.1039/c9md00018f
Choice A:Reduces the binding affinity of the agent
Choice B:Prolongs its blood circulation half-life
Choice C:Reduces tumor accumulation
Choice D:Reduces bone marrow toxicity
Question 5: The radiobiology of a theranostic agent is affected by
Reference:Morris ZS, Wang AZ, Knox SJ. The Radiobiology of Radiopharmaceuticals. Semin Radiat Oncol. 2021 Jan;31(1):20-27. doi: 10.1016/j.semradonc.2020.07.002. PMID: 33246632
Choice A:DNA damage repair in tumor cells
Choice B:The half-life of the radionuclide that is delivered
Choice C:Tumor-infiltrating immune cells
Choice D:All of the above
Question 6: The following statements about the effects of theranostics on anti-tumor immunity are true EXCEPT
Reference:Jagodinsky JC, Bates AM, Hernandez R, Grudzinski JJ, Marsh IR, Chakravarty I, Arthur IA, Zangl LM, Brown RJ, Nystuen EJ, Emma SE, Kerr C, Jin WJ, Carlson PM, Engle JW, Aluicio-Sarduy E, Barnhart TE, Le T, Kim KM, Bednarz BP, Weichert JP, Patel RB, Morris ZS. Temporal analysis of type 1 interferon activation in tumor cells following external beam radiotherapy or targeted radionuclide therapy. Theranostics. 2021 Apr 15;11(13):6120-6137. doi: 10.7150/thno.54881. eCollection 2021. PMID: 33995649 Patel RB, Hernandez R, Carlson P, Grudzinski J, Bates AM, Jagodinsky JC, Erbe A, Marsh IR, Arthur I, Aluicio-Sarduy E, Sriramaneni RN, Jin WJ, Massey C, Rakhmilevich AL, Vail D, Engle JW, Le T, Kim K, Bednarz B, Sondel PM, Weichert J, Morris ZS. Low-dose targeted radionuclide therapy renders immunologically cold tumors responsive to immune checkpoint blockade. Sci Transl Med. 2021 Jul 14;13(602):eabb3631. doi: 10.1126/scitranslmed.abb3631. PMID: 34261797
Choice A:Delivering radiation to all tumor sites may enhance anti-tumor immune response
Choice B:Theranostics can activate a type I interferon response in preclinical tumor models
Choice C:Decay of radionuclides in the tumor microenvironment prevents anti-tumor immune response
Choice D:Low dose theranostics enhance clonal expansion of tumor-infiltrating T cells in combination with immune checkpoint blockade in preclinical tumor models
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