Tüm Vücut Tomografide Aynı Yaş Grubundaki Erkek ve Kız Pediatrik Fantom Dozlarının Karşılaştırılması: Monte Carlo Simülasyon Çalışması

Yıl 2018, Cilt: 4 Sayı: 2, 29 - 39, 12.09.2018

Handan Tanyildizi , Mustafa Demir Baki Akkuş

Öz

Amaç:
Bu çalışmada, Monte Carlo yöntemi kullanılarak tüm vücut tomografi uygulanan
aynı yaş grubundaki erkek ve kız pediatrik fantomları üzerinden organ
dozlarının hesaplanması ve karşılaştırılması amaçlanmıştır. Materyal ve Metot: Simülasyon
VirtualDose programında, tüp voltajı 100 kVp, akım ışınlama süresi 100 mAs, doz
indeksi (CTDI) 5,31 olan GE Discovery CT750 HD model tomografi cihazına göre
yapılmıştır. Aynı yaş grubundaki erkek ve kız pediatrik fantomları için ICRP-89
raporunda belirtilen yeni doğan, 1, 5, 10 ve 15 yaş olmak üzere 5 grup anatomik
fantom kullanılmıştır. Bulgular: Total
efektif doz değeri yeni doğan, 1, 5, 10 ve 15 yaş grubu için sırasıyla 13.92,
12.28, 11.70, 10.31 ve 8.82 bulundu. Yeni doğan grubunda erkek fantom testis
dozu 14.08 mGy, kız fantom ovaryum dozu 13.05 mGy bulundu. 1 yaş grubunda erkek
fantom testis ve prostat dozları 14.92 ve 12.24 mGy, kız fantom ovaryum ve
rahim dozları 12.44 ve 10.98 mGy bulundu. 5 yaş grubunda erkek fantom testis ve
prostat dozları 14.33 ve 12.53 mGy, kız fantom ovaryum ve rahim dozları 11.65
ve 10.25 mGy bulundu. 10 yaş grubunda erkek fantom testis ve prostat dozları
13.69 ve 10.80 mGy, kız fantom ovaryum ve rahim dozları 9.51 ve 8.50 mGy
bulundu. 15 yaş grubunda erkek fantom beyin, kolon, karaciğer, mide, testis,
tiroid, böbreküstü bezi, safra kesesi, böbrek, pankreas, prostat, ince barsak,
spinal kord, dalak, timüs dozları 8.81, 8.51, 8.60, 8.22, 12.43, 12.76, 7.36,
7.44, 8.49, 6.88, 7.88, 9.84, 7.42, 8.48, 8.45, 8.56 mGy, kız fantom beyin,
kolon, karaciğer, mide, ovaryum, tiroid, böbreküstü bezi, safra kesesi, böbrek,
pankreas, rahim, ince barsak, spinal kord, dalak, timüs dozları 9.30, 10.45,
9.34, 9.41, 7.95, 14.66, 7.85, 8.33, 10.10, 8.39, 8.86, 6.88, 9.11, 9.03, 9.48,
9.32 mGy bulundu. Sonuç: 5 grupta
total efektif doz değerinde cinsiyete bağlı bir farklılık görülmemiştir. 5
grupta erkek fantom testis dozu, kız fantom ovaryum dozuna göre yüksek
bulunmuştur. Yeni doğan, 1, 5, 10 yaş kız ve erkek fantom organ dozlarında
anlamlı bir farklılık bulunmazken 15 yaş grubunda doz dağılımları değişmiştir.

Anahtar Kelimeler

Monte Carlo Simülasyonu, Pediatrik Fantom, Efektif Doz

Comparison of Male and Female Pediatric Phantom Doses in the Same Age Group on Whole Body Tomography: A Monte Carlo Simulation Study

Öz

Objective:
In this study, it was aimed to calculate and compare organ doses of male and
female pediatric phantoms in the same age group applied whole body tomography
using Monte Carlo method. Materials and
Methods: The simulation was performed on a GE Discovery CT750 HD model
tomography instrument with a tube voltage of 100 kVp, a current irradiation
time of 100 mAs and a dose index (CTDI) of 5,31 in the VirtualDose program.
Five groups of anatomic phantoms called new born, 1, 5, 10 and 15 years old, as
stated in the ICRP-89 report for male and female phantoms in the same age group,
were used. Results: The total
effective dose was found 13.92, 12.28, 11.70, 10.31 and 8.82 for new born, 1,
5, 10 and 15 years old groups, respectively. New born group male phantom testes
dose was found 14.08 mGy, female phantom ovaries dose was found 13.05 mGy. In
the 1 year old group male phantom testes and prostate doses were found 14.92
and 12.24 mGy, female phantom ovaries and uterus doses were found 12.44 and
10.98 mGy, respectively. In the 5 year old group male phantom testes and
prostate doses were found 14.33 and 12.53 mGy, female phantom ovaries and uterus
doses were found 11.65 and 10.25 mGy, respectively. In the 10 year old group
male phantom testes and prostate doses were found 13.69 and 10.80 mGy, female
phantom ovaries and uterine doses were found 9.51 and 8.50 mGy, respectively. In
the 15 year old male phantom doses of brain, colon, liver, stomach, testes,
thyroid, adrenal, gall bladder, kidney, pancreas, prostate, small intestine,
spinal cord, spleen, thymus were found 8.81, 8.51, 8.60, 8.22, 12.43, 12.76,
7.36, 7.44, 8.49, 6.88, 7.88, 9.84, 7.42, 8.48, 8.45, 8.56 mGy, female phantom doses
of brain, colon, liver, stomach, ovaries, thyroid, adrenal, gall bladder,
kidney, pancreas, uterus, small intestine, spinal cord, spleen, thymus were
found 9.30, 10.45, 9.34, 9.41, 7.95, 14.66, 7.85, 8.33, 10.10, 8.39, 8.86,
6.88, 9.11, 9.03, 9.48, 9.32 mGy. Conclusion:
There was no sex-dependent difference in total effective dose in 5 groups. Male
phantom testes doses in 5 groups were found higher than female phantom ovarium
doses. There is no significant difference in organ doses of newborn, 1, 5, 10
year old male and female phantoms out of 15 year old.

Anahtar Kelimeler

Monte Carlo Simulation, Pediatric Phantom, Effective Dose

Kaynakça

• 1. UNSCEAR. Sources And Effects Of Ionizing Radiation, UNSCEAR Publications. vol. I. New York: United Nations Scientific Committee on the Effects of Atomic Radiation; 2008.
• 2. ICRP. Managing patient dose in computed tomography. ICRP Publication 87. Ann ICRP. 2000;30(4):1–86.
• 3. Valentin J, ICRP. Managing patient dose in multi-detector computed tomography(MDCT). ICRP Publication 102. Ann ICRP. 2007;37(1):1–79.
• 4. Dauer LT, Hricak H. Addressing the Challenge of Managing Radiation Use in Medical Imaging: Paradigm Shifts and Strategic Priorities. Oncology-Ny. 2014;28(3):243–+.
• 5. ICRP. Recommendations of the International Commission on Radiological Protection. ICRP Publication 26. Annals ICRP. 1977;1(3):1–80.
• 6. ICRP. 1990 Recommendations of the International Commission on Radiological Protection. ICRP Publication 60. Ann ICRP. 1991;21(1-3):1–201.
• 7. ICRP. The 2007 Recommendations of the International Commission on Radiological Protection. ICRP Publication 103. Ann ICRP. 2007;37(2-4):1–332.
• 8. ICRP. Radiation Protection in Medicine. ICRP Publication 105. Ann ICRP. 2007;37(6):1–63.
• 9. UNSCEAR. Sources, Effects And Risks Of Ionizing Radiation, UNSCEAR Publications. vol. II. New York: United Nations Scientific Committee on the Effects of Atomic Radiation; 2013.
• 10. Brenner D, Elliston C, Hall E, Berdon W. Estimated risks of radiation-induced fatal cancer from pediatric CT. AJR Am J Roentgenol. 2001;176(2):289–96.
• 11. Brenner DJ. Estimating cancer risks from pediatric CT: going from the qualitative to the quantitative. Pediatr Radiol. 2002;32(4):228–1. discussion 242-224.
• 12. Turner AC, Zhang D, Khatonabadi M, Zankl M, DeMarco JJ, Cagnon CH, Cody DD, Stevens DM, McCollough CH, McNitt-Gray MF. The feasibility of patient size-corrected, scanner-independent organ dose estimates for abdominal CT exams. Med Phys. 2011;38(2):820–9.
• 13. Brady Z, Cain TM, Johnston PN. Comparison of organ dosimetry methods and effective dose calculation methods for paediatric CT. Australas Phys Eng Sci Med. 2012;35(2):117–34.
• 14. Lee C, Kim KP, Long DJ, Bolch WE. Organ doses for reference pediatric and adolescent patients undergoing computed tomography estimated by Monte Carlo simulation. Med Phys. 2012;39(4):2129–46.
• 15. Tian X, Li X, Segars WP, Frush DP, Paulson EK, Samei E. Dose coefficients in pediatric and adult abdominopelvic CT based on 100 patient models. Phys Med Biol. 2013;58(24):8755–68.
• 16. Kost SD, Fraser ND, Carver DE, Pickens DR, Price RR, Hernanz-Schulman M, Stabin MG. Patient-specific dose calculations for pediatric CT of the chest, abdomen and pelvis. Pediatr Radiol. 2015;45(12):1771–80.
• 17. Ding A, Gao Y, Liu H, Caracappa PF, Long DJ, Bolch WE, Liu B, Xu XG. VirtualDose: a software for reporting organ doses from CT for adult and pediatric patients. Phys Med Biol. 2015;60(14):5601–25.
• 18. Papadakis AE, Perisinakis K, Damilakis J. Development of a method to estimate organ doses for pediatric CT examinations. Med Phys. 2016;43(5):2108.
• 19. Pearce MS, Salotti JA, Little MP, McHugh K, Lee C, Kim KP, Howe NL, Ronckers CM, Rajaraman P, Craft AW, et al. Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study. Lancet. 2012;380(9840):499–505.
• 20. Miglioretti DL, Johnson E, Williams A, Greenlee RT, Weinmann S, Solberg LI, Feigelson HS, Roblin D, Flynn MJ, Vanneman N, et al. The use of computed tomography in pediatrics and the associated radiation exposure and estimated cancer risk. JAMA Pediatr. 2013;167(8):700–7.