Abstract

Accurate dosimetry is essential in nuclear medicine for optimizing radionuclide therapies and ensuring patient safety. In Radiopharmaceutical dosimetry the Medical Internal Radiation Dosimetry (MIRD)Society is the pioneer in organ-level dosimetry providing the fundamental basis for commonly used clinical and research dosimetry software like MIRDOSE and OLINDA/EXM. Recently, in MIRD Pamphlet No. 28, Part 1, the MIRD committee of the Society of Nuclear Medicine and Medical Imaging presented a new Software Tool; MIRDcalc, for organ-level and sub-organ tissue dosimetry, based on a standard Excel spreadsheet platform to enhance personalized internal dosimetry. This study evaluates and compares the internal dosimetry software MIRDcalc and OLINDA/EXM for calculating absorbed and effective doses in neuroendocrine tumor (NET) patients treated with Lutetium-177 DOTATATE, based on quantitative SPECT/CT imaging data. MIRDcalc, a freely accessible Excel-based dosimetry tool, integrates updated anatomical models, user-friendly interfaces, and quality control utilities. Its performance was assessed against OLINDA/EXM, a widely used commercial software, and benchmarked using the standardized absorbed radiation dose calculation equations, described in MIRD primer 2022. Dose estimates for key organs were derived using both platforms, and results demonstrated a high level of concordance between the two methodologies. Minor discrepancies in absorbed dose values were attributed to differences in underlying phantom models, organ definitions, and dose calculation algorithms. The analysis underscores MIRDcalc’s viability as a research-grade tool for personalized dosimetry, offering comparable accuracy to established systems like OLINDA/EXM. Future work should focus on expanding personalized dosimetry, especially for Lu177 DOTATATE, NET patients for Radionuclide therapy capabilities and validating models across broader clinical datasets.

Keyword: MIRDcalc, OLINDA/EXM, Lu-177 DOTATATE, absorbed dose, effective dose, internal dosimetry, SPECT/CT, radionuclide therapy

Full Text PDF

Refrences:

1. Schlafke-Stelson AT, Watson EE, Cloutier RJ. A history of medical internal dosimetry. Health Phys. 1995;69:766–782. doi:10.1097/00004032-199511000-00011. PubMed: 7558867.
2. Loeevinger R, Berman M. A schema for absorbed-dose calculations for biologically-distributed radionuclides. J Nucl Med. 1968 Feb:Suppl 1:9-14. PMID: 5646656.
3. Loevinger R, Budinger TF, Watson EE, Society of Nuclear Medicine. Medical Internal Radiation Dose Committee. MIRD Primer for Absorbed Dose Calculations. Rev ed. New York: Society of Nuclear Medicine; 1991.
4. Bolch WE, Eckerman KF, Sgouros G, Thomas SR. MIRD Pamphlet No. 21: A generalized schema for radiopharmaceutical dosimetry—standardization of nomenclature. J Nucl Med. 2009;50:477 484. doi:10.2967/jnumed.108.056036. PubMed: 19258258.
5. Stabin MG. MIRDOSE: Personal computer software for internal dose assessment in nuclear medicine. J Nucl Med. 1996;37:538–546. PubMed: 8772664.
6. Stabin MG, Siegel JA. Physical models and dose factors for use in internal dose assessment. Health Phys. 2003;85:294–310. doi:10.1097/00004032-200309000-00006. PubMed: 12938720.
7. Stabin MG, Sparks RB, Crowe E. OLINDA/EXM: The second-generation personal computer software for internal dose assessment in nuclear medicine. J Nucl Med. 2005;46:1023–1027. PubMed: 15937315.
8. Kesner AL, Carter LM, Ramos JC, Lafontaine D, Olguin EA, Brown JL, et al. MIRD pamphlet no. 28, part 1: MIRDcalc—a software tool for medical internal radiation dosimetry. J Nucl Med. 2023;64(7):1117–1124.
9. Carter LM, Ocampo Ramos JC, Olguin EA, Brown JL, Lafontaine D, Jokisch DW, Bolch WE, Kesner AL. MIRD Pamphlet No. 28, Part 2: Comparative evaluation of MIRDcalc Dosimetry Software across a compendium of diagnostic radiopharmaceuticals. J Nucl Med. 2023 Aug;64(8):1295-1303. doi: 10.2967/jnumed.122.264230.
10. International Commission on Radiological Protection (ICRP). The 2007 Recommendations of the International Commission on Radiological Protection. ICRP publication 103. Ann ICRP. 2007;37(2-4):1-332. doi: 10.1016/j.icrp.2007.10.003. PMID: 18082557.
11. Mattsson S, Johansson L, Leide Svegborn S, Liniecki J, Noßke D, Riklund KÅ, et al. Radiation dose to patients from radiopharmaceuticals: a compendium of current information related to frequently used substances. Ann ICRP. 2015 Jul;44(2 Suppl):7–321. doi: 10.1177/0146645314558019.
12. Grosswendt B. ICRP Publication 110. Radiat Prot Dosimetry. 2012 Jun;150(1):124–6. doi: 10.1093/rpd/ncs059.
13. Bolch WE, Eckerman K, Endo A, Hunt JGS, Jokisch DW, Kim CH, et al. ICRP Publication 143: Paediatric reference computational phantoms. Ann ICRP. 2020;49:5–297. doi:10.1177/01466453 20915031. PubMed: 33000625.
14. Bolch WE, Jokisch D, Zankl M, Eckerman KF, Fell T, Manger R, et al. ICRP Publication 133: The ICRP computational framework for internal dose assessment for reference adults: Specific absorbed fractions. Ann ICRP. 2016;45(2):1–74.

15. Gear JI, Cox MG, Gustafsson J, Gleisner KS, Murray I, Glatting G, et al. EANM practical guidance on uncertainty analysis for molecular radiotherapy absorbed dose calculations. Eur J Nucl Med Mol Imaging. 2018;45:2456–2474. doi:10.1007/s00259-018-4136-7. PubMed: 30218316.
16. Loevinger R, Budinger TF, Watson EE. MIRD primer for absorbed dose calculations. Rev ed. New York: Society of Nuclear Medicine; 1991.
17. Bartlett RM, Bolch WE, Brill AB, Dewaraja YK, Fahey FH, Fisher DR, Hobbs RF, Howell RW, Meredith RF, Rajendran JG, Sgouros G, Zanzonico P. MIRD primer 2022: Complete Guide to Radiopharmaceutical Dosimetry. Reston, VA: Society of Nuclear Medicine & Molecular Imaging; 2022.
18. Dewaraja YK, Frey EC, Sgouros G, Brill AB, Roberson P, Zanzonico PB, et al. MIRD Pamphlet No. 23: Quantitative SPECT for patient-specific 3-dimensional dosimetry in internal radionuclide therapy. J Nucl Med. 2012;53:1310–1325. doi:10.2967/jnumed.111.100123. PubMed: 22743252.
19. Ljungberg M, Celler A, Konijnenberg MW, Eckerman KF, Dewaraja YK, Sjögreen-Gleisner K, et al. MIRD Pamphlet No. 26: Joint EANM/MIRD Guidelines for Quantitative 177Lu SPECT Applied for Dosimetry of Radiopharmaceutical Therapy. J Nucl Med. 2016;57:151–162. doi:10.2967/jnumed.115.159012. PubMed: 26471692.
20. Sgouros G, Bolch WE, Chiti A, Dewaraja YK, Emetzoglou D, Hobbs RF, et al. ICRU Report 96: Dosimetry-guided radiopharmaceutical therapy. J ICRU. 2021;21:1–212. doi:10.1177/ 14736691211060117.
21. Hindorf C. Internal dosimetry. In: Bailey DL, Humm JL, Todd-Pokropek A, van Aswegen A, editors. Nuclear Medicine Physics: A Handbook for Teachers and Students. Vienna: International Atomic Energy Agency; 2015.
22. Snyder WS, Ford MR, Warner GG, Watson SB. “S” absorbed dose per unit cumulated activity for selected radionuclides and organs. MIRD Pamphlet No. 11. New York: Society of Nuclear Medicine; 1975.
23. Olguin E, President B, Ghaly M, Frey E, Sgouros G, Bolch WE. Specific absorbed fractions and radionuclide S-values for tumors of varying size and composition. Phys Med Biol. 2020;65:235015. doi:10.1088/1361-6560/abbc7e. PubMed: 32992308.
24. Capala J, Graves SA, Scott A, Sgouros G, James SS, Zanzonico P, Zimmerman BE. Dosimetry for radiopharmaceutical therapy: Current practices and commercial resources. J Nucl Med. 2021;62(Suppl 3):3S–11S. doi:10.2967/jnumed.121.262749. PubMed: 34857621.
25. Katugampola S, Wang J, Rosen A, Howell RW, SNMMI MIRD committee. MIRD Pamphlet No. 27: MIRDcell V3, a revised software tool for multicellular dosimetry and bioeffect modeling. J Nucl Med. 2022;63:1441–1449. doi:10.2967/jnumed.121.263253. PubMed: 35145016.
26. Roedler HD. Accuracy of internal dose calculations with special consideration of radiopharmaceutical biokinetics. In: Watson EE, Schlafke-Stelson AT, Coffey JL, Cloutier RJ, editors. Third International Radiopharmaceutical Dosimetry Symposium (HHS Publication FDA 81-8166). Oak Ridge (TN): Oak Ridge Associated Universities; 1981. p. 1–20.
27. Andersson M, Johansson L, Minarik D, Leide-Svegborn S, Mattsson S. Effective dose to adult patients from 338 radiopharmaceuticals estimated using ICRP biokinetic data, ICRP/ICRU computational reference phantoms and ICRP 2007 tissue weighting factors. EJNMMI Phys. 2014;1:9. doi:10.1186/2197-7364-1-9. PubMed: 26501451.
28. Stabin M, Adam Farmer. OLINDA/EXM 2.0: The new generation dosimetry modeling code. Nucl
Med. 2012;53(Suppl 1):585.
29. Stabin MG, Siegel JA. RADAR dose estimate report: A compendium of radiopharmaceutical dose estimates based on OLINDA/EXM version 2.0. J Nucl Med. 2018;59:154–160. doi:10.2967/ jnumed.117.196261. PubMed: 28887400.
30. Subramanian S, He B, Frey E, Jokisch DW, Bolch W, Sgouros G. Improved accuracy of S-value based dosimetry: A guide to transition from Cristy–Eckerman to ICRP adult phantoms. EJNMMI Phys. 2022;9:57. doi:10.1186/s40658-022-00485-9. PMID: 36018453.