Radyonüklidlerle Görüntüleme ve Tedavide Radyasyon Maruziyeti
Özet
Nükleer tıp kliniklerinde kullanılan radyofarmasötikler, hastalıkların erken teşhisi, karakterizasyonu ve tedavisi amacıyla sisteme uygulanan radyoaktif bileşiklerdir. Bu süreçte atomun radyoaktif bozunmasıyla alfa, beta ve gama radyasyon salınımı gerçekleşmekte, tanısal görüntülemede gama kameralar ve PET tarayıcılar aracılığıyla fiziksel sinyaller detekte edilmektedir. Tanısal uygulamalarda Teknesyum (99mTc), Flor (18F) ve Galyum (68Ga) gibi kısa yarı ömürlü radyonüklidler öne çıkarken, radyonüklid tedavilerde daha çok saf beta emisyonu yapan ajanlar tercih edilmektedir. Hastaların maruz kaldığı efektif radyasyon dozları; ICRP ve MIRD modelleriyle doku ağırlık faktörlerine ve miksiyon aralıklarına göre hesaplanır. İyi hidrasyon ve sık idrara çıkma, hastanın aldığı radyasyon dozunu anlamlı derecede azaltır. Tanısal incelemeler sonrasında hanehalkı ve toplum için ek önlemlere nadiren ihtiyaç duyulurken, BT bileşeninin total doza 1-20 mSv katkı sağladığı PET/BT gibi hibrit sistemlerde ve radyonüklid tedavi protokollerinde radyasyon maruziyeti daha dikkatli yönetilmelidir. Emziren annelerde iç kontaminasyonu önlemek adına belirli sürelerde emzirmeye ara verilmesi veya tedaviden önce emzirmenin tamamen durdurulması kritiktir.
Radiopharmaceuticals utilized in nuclear medicine clinics are radioactive compounds systematically administered for the early detection, characterization, and treatment of various diseases. During this process, radioactive decay of atoms results in alpha, beta, and gamma radiation emissions, where physical signals are detected via gamma cameras and PET scanners for diagnostic imaging. While short half-life radionuclides like Technetium (99mTc), Fluorine (18F), and Gallium (68Ga) stand out in diagnostic procedures, pure beta-emitting agents are preferred in radionuclide therapy. The effective radiation doses received by patients are computed using tissue weighting factors and voiding intervals via ICRP and MIRD models. Adequate hydration and frequent urination significantly reduce the internal radiation dose. Following diagnostic examinations, additional precautions for the public and household members are rarely required. However, radiation exposure must be managed more cautiously in radionuclide therapies and hybrid systems like PET/CT, where the CT component contributes an additional 1–20 mSv to the total patient dose. To prevent internal contamination in breastfeeding mothers, interrupting breastfeeding for specified periods or discontinuing it entirely prior to therapy remains vital.
Referanslar
Mettler F.A, Guiberteau MJ. (2019). Essentials of Nuclear Medicine Imaging (Seventh Edition),W.B. Saunders.
Salvatori M. et al. (2017) Radiobiology and Radiation Dosimetry in Nuclear Medicine. In: Strauss H., Mariani G., Volterrani D., Larson S. (eds) Nuclear Oncology. Springer, Cham. https://doi.org/10.1007/978-3-319-26236-9_6
Stabin, Michael. (2008). Fundamentals of Nuclear Medicine Dosimetry. 10.1007/978-0-387-74579-4.
Stabin MG, Tagesson M, Thomas SR, Ljungberg M, Strand SE. Radiation dosimetry in nuclear medicine. Appl Radiat Isot. 1999 Jan;50(1):73-87. doi: 10.1016/s0969-8043(98)00023-2. PMID: 10028629.
Visser EP, J de Jong. Radiation Dosimetry in Nuclear Medicine. PART V:752-778. https://richtlijnendatabase.nl/gerelateerde_documenten/f/17253/Radiation%20Dosimetry%20in%20Nuclear%20Medicine.pdf
Stabin MG et al. (2004) Voxel-based mouse and rat models for internal dose calculations [abstract]. J Nucl Med.; 45:634-635(suppl):57P
ICRP, 1977. Recommendations of the ICRP. ICRP Publication 26. Ann. ICRP 1 (3).
ICRP, 1988. Radiation Dose to Patients from Radiopharmaceuticals. ICRP Publication 53. Ann. ICRP 18 (1-4).
ICRP, 1991. 1990 Recommendations of the International Commission on Radiological Protection. ICRP Publication 60. Ann. ICRP 21 (1-3).
ICRP, 1992. Radiological Protection in Biomedical Research. ICRP Publication 62. Ann. ICRP 22 (3).
ICRP, 1994. Dose Coefficients for Intakes of Radionuclides by Workers. ICRP Publication 68. Ann. ICRP 24 (4).
ICRP, 1998. Radiation Dose to Patients from Radiopharmaceuticals (Addendum to ICRP Publication 53). ICRP Publication 80. Ann. ICRP 28 (3).
ICRP, 2007. The 2007 Recommendations of the International Commission on Radiological Protection. ICRP Publication 103. Ann. ICRP 37 (2-4).
ICRP, 2008. Radiation Dose to Patients from Radiopharmaceuticals - Addendum 3 to ICRP Publication 53. ICRP Publication 106. Ann. ICRP 38 (1-2).
Cristy, M., Eckerman, K.F. (1987). Specific absorbed fractions of energy at various ages from internal photon sources (ORNL/TM--8381/V7).
Senthamizhchelvan S, Bravo PE, Esaias C, et al. Human biodistribution and radiation dosimetry of 82Rb. J Nucl Med. 2010 ;51(10):1592-1599. doi:10.2967/jnumed.110.077669.
Law M, Ma WH, Leung R, Li S, Wong KK, Ho WY, Kwong A. Evaluation of patient effective dose from sentinel lymph node lymphoscintigraphy in breast cancer: a phantom study with SPECT/CT and ICRP-103 recommendations. Eur J Radiol. 2012 May;81(5):e717-20. doi: 10.1016/j.ejrad.2012.01.035. Epub 2012 Mar 2. PMID: 22386916.
Fettich, J., Colarinha, P., Fischer, S. et al. Guidelines for direct radionuclide cystography in children. Eur J Nucl Med Mol Imaging 30, B39–B44 (2003). https://doi.org/10.1007/s00259-003-1137-x
Russell JR, Stabin MG, Sparks RB, Watson E. Radiation absorbed dose to the embryo/fetus from radiopharmaceuticals. Health Phys. 1997 Nov;73(5):756-69. doi: 10.1097/00004032-199711000-00003. PMID: 9378651.
Ahlgren L, Ivarsson S, Johansson L, Mattsson S, Nosslin B. Excretion of radionuclides in human breast milk after the administration of radiopharmaceuticals. J Nucl Med. 1985 Sep;26(9):1085-90. PMID: 4032049.
Berke RA, Hoops EC, Kereiakes JC, Saenger EL. Radiation dose to breast-feeding child. J Nucl Med. 1973 Jan;14(1):51-2. PMID: 4682152.
ICRP, 2004. Release of Patients after Therapy with Unsealed Radionuclides. ICRP Publication 94. Ann. ICRP 34 (2)
Hänscheid, H., Canzi, C., Eschner, W. et al. EANM Dosimetry Committee Series on Standard Operational Procedures for Pre-Therapeutic Dosimetry II. Dosimetry prior to radioiodine therapy of benign thyroid diseases. Eur J Nucl Med Mol Imaging 40, 1126–1134 (2013). https://doi.org/10.1007/s00259-013-2387-x
Gear, J., Chiesa, C., Lassmann, M. et al. EANM Dosimetry Committee series on standard operational procedures for internal dosimetry for 131I mIBG treatment of neuroendocrine tumours. EJNMMI Phys 7, 15 (2020). https://doi.org/10.1186/s40658-020-0282-7
Bagheri, R., Afarideh, H., Ghannadi-Maragheh, M. et al. Dosimetric study of radium-223 chloride and 153Sm-EDTMP for treatment of bone metastases using MCNPX code and available experimental data. J Radioanal Nucl Chem 303, 1991–1998 (2015). https://doi.org/10.1007/s10967-014-3641-9
Cremonesi, Marta & Ferrari, Mahila & Bodei, L. & Bartolomei, M. & Chinol, M. & Mei, R. & Daou, B. & Tosi, G. & Paganelli, G.. (2006). Dosimetry in patients undergoing Lu-177-DOTATATE therapy with indications for Y-90-DOTATATE. European journal of nuclear medicine and molecular imaging. 33. S102-S102.
Kam, B.L.R., Teunissen, J.J.M., Krenning, E.P. et al. Lutetium-labelled peptides for therapy of neuroendocrine tumours. Eur J Nucl Med Mol Imaging 39, 103–112 (2012). https://doi.org/10.1007/s00259-011-2039-y
Kratochwil, C., Fendler, W.P., Eiber, M. et al. EANM procedure guidelines for radionuclide therapy with 177Lu-labelled PSMA-ligands (177Lu-PSMA-RLT). Eur J Nucl Med Mol Imaging 46, 2536–2544 (2019). https://doi.org/10.1007/s00259-019-04485-3
Blake GM, Naeem M, Boutros M. Comparison of effective dose to children and adults from dual X-ray absorptiometry examinations. Bone. 2006 Jun;38(6):935-42. doi: 10.1016/j.bone.2005.11.007. Epub 2005 Dec 22. PMID: 16376161
