Dosimetric Examination of Out-of-Field Doses with TLD in Breast Irradiation with Different Radiotherapy Techniques

Abstract

Objective: In this study, the dose absorbed in different organs on a phantom imitating the real patient receiving radiotherapy for breast cancer was investigated. Treatment planning system (TPS) and thermoluminescence dosimeter (TLD) dose measurements were compared for the mean dose in different organs. Methods: Left breast tissue on Alderson female rando phantom was selected as the target treatment volume. Treatment plans specific to the applications performed with different treatment techniques in the Varian DHX device were selected (3DCRT, 5 Fields- IMRT, 7 Fields- IMRT). After TLD-100 dosimeters were placed in the places in the determined volume in the phantom, they were irradiated. Then, the dose measurements obtained for each technique were compared with the TPS doses. Results: The statistical significance between TPS doses and TLD doses for the mean dose value of the planned target volume (PTV) in 3DCRT, 5 Fields- IMRT, 7 Fields- IMRT techniques were found as p = 0.042, p = 0.002 and p = 0.030, respectively. It was observed that the difference between TPS and TLD doses increased in the plans made with the IMRT technique in the mean dose of the thyroid. When the fetus doses were examined, the dose was not determined with TPS, while the average fetus dose was found to be 3.13-16.87 cGy with TLD. In addition, when the parotid doses were examined, the dose was not determined with TPS, while the mean parotid dose was measured as 10.37-57.75 cGy with TLD. Conclusion: It can be said that TPS fails to estimate organ doses at distances greater than 8 cm. It will be more advantageous to choose the 3DCRT treatment technique in breast radiotherapy. Keywords: Thermoluminescence dosimeter, Breast radiotherapy, Out of field dose

Keywords

• hermoluminescence dosimeter
• Breast radiotherapy
• Out of field dose

Farklı Radyoterapi Teknikleri İle Meme Işınlamalarında Alan Dışı Dozların TLD İle Dozimetrik Olarak İncelenmesi

Abstract

Öz Amaç: Bu çalışmada meme kanseri nedeniyle radyoterapi alan gerçek hastayı taklit eden bir fantom üzerinde farklı organlarda absorbe edilen doz araştırılmıştır. Farklı organlardaki ortalama doz için tedavi planlama sistemi (TPS) ve termolüminesans dozimetre (TLD) doz ölçümleri karşılaştırılmıştır. Gereç ve Yöntemler: Alderson kadın rando fantom üzerinde sol meme dokusu hedef tedavi hacmi olarak seçildi. Varian DHX cihazında farklı tedavi teknikleri ile yapılmış uygulamalara özel tedavi planları belirlendi (3DCRT, 5 Alan- IMRT, 7 Alan- IMRT). Fantomda belirlenen hacim içindeki yerlere TLD-100 dozimetreleri yerleştirildikten sonra ışınlandı. Daha sonra her bir teknik için elde edilen doz ölçümleri TPS dozları ile karşılaştırıldı. Bulgular: 3DCRT, 5 Alan- IMRT ve 7 Alan- IMRT tekniklerinde planlanan hedef volümün (PTV) ortalama doz değeri için TPS dozları ve TLD dozları arasındaki istatistiksel anlamlılık sırasıyla, p=0.042, p=0.002 ve p=0.030 olarak bulunmuştur. Tiroid’in ortalama dozunda IMRT tekniği ile yapılan planlarda TPS ve TLD dozları arasındaki farkın arttığı görülmüştür. Fetüs dozları incelendiğinde TPS ile doz saptanmazken TLD ile ortalama fetüs dozu 3.13-16.87 cGy olarak bulunmuştur. Ayrıca parotis dozları incelendiğinde TPS ile doz saptanmazken TLD ile ortalama parotis dozu 10.37- 57.75 cGy olarak ölçülmüştür. Sonuç: TPS’in 8 cm’den uzak mesafelerde organ dozlarını tahmin etmede başarısız olduğu söylenebilir. Meme radyoterapisinde 3DCRT tedavi tekniğinin tercih edilmesi daha avantajlı olacaktır. Anahtar Kelimeler: Termolüminesans dozimetre, Meme radyoterapi, Alan dışı doz

Keywords

• Termolüminesans dozimetre
• Meme radyoterapi
• Alan dışı doz

References

1. [1] Jemal A, Bray F, Center MM, Ferlay J, Ward E, Forman D. Global cancer statistics. CA Cancer J Clin 2011;61(2):69- 90
2. [2] Aras S, Ikizceli T, Aktan M. Dosimetric Comparison of Three-Dimensional Conformal Radiotherapy (3D-CRT) and Intensity Modulated Radiotherapy Techniques (IMRT) with Radiotherapy Dose Simulations for Left-Sided Mastectomy Patients. Eur J Breast Health. 2019;15(2):85-9.
3. [3] Adam D, Suditu MB, Popa R, Ciocaltei V. Volumetrıc-modulated arc therapy vs. 3dconformal radiotherapy for breast cancer. Romanian Reports in Physics. 2015; 67(3):978–986.
4. [4] Berris T, Mazonakis M, Stratakis J, Tzedakis A, Fasoulaki A, Damilakis J. Calculation of organ doses from breast cancer radiotherapy: a Monte Carlo study. J Appl Clin Med Phys. 2013;14:4029. doi: 10.1120/jacmp.v14i1.4029. PubMed PMID: 23318389; PubMed Central PMCID: PMC5713920.
5. [5] Sant M, Allemani C, Santaquilani M, Knijn A, Marchesi F, Capocaccia R. UROCARE-4. Survival of cancer patients diagnosed in 1995–1999. Re-sults and commentary. Eur J Cancer. 2009;45:931-91. doi: 10.1016/j.ejca.2008.11.018.
6. [6] Lee B, Ahn SH, Kim H, Son J, Sung J, Han Y, Huh SJ, Kim JS, Kim DW, Yoon M. Radiotherapy-induced secondary cancer risk for breast cancer: 3D conformal therapy versus IMRT versus VMAT. J Radiol Prot 2014;34:325-331.
7. [7] D’Arienzo M, Masciullo SG, de Sanctis V, Osti MF, Chiacchiararelli L, Enrici RM. Integral dose and radiation-induced secondary malignancies: com-parison between stereotactic body radiation thera-py and three-dimensional conformal radiotherapy. Int J Environ Res Public Health. 2012;9:4223-40. doi: 10.3390/ijerph9114223. PubMed PMID: 23202843; PubMed Central PMCID: PMC3524624.
8. [8] Joosten A, Bochud F, Baechler S, Levi F, Mirimanoff RO, Moeckli R. Variability of a peripheral dose among various linac geometries for second cancer risk assessment. Phys Med Biol. 2011;56:5131-51. doi: 10.1088/0031-9155/56/16/004. PubMed PMID: 21775792.

9. [9] The International Commission on Radiological Protection. Human carcinogenic risk from intra‑uterine radiation. In: Biological Effects after Prenatal Irradiation (Embryo and Fetus), ICRP Report 90. Oxford, UK: Elsevier Ltd.; 2003. p. 176‑82.
10. [10] D S Sharma, Animesh, S S Deshpande, R D Phurailatpam, D D Deshpande, S K Shrivastava, K A Dinshaw. Peripheral dose from uniform dynamic multileaf collimation fields: implications for sliding win-dow intensity-modulated radiotherapy. Br J Ra-diol. 2006;79:331-5. doi: 10.1259/bjr/16208090. PubMed PMID: 16585727.
11. [11] Banaee N, Nedaie H, Esmati E, Nosrati H, Jamali M. Dose measurement outside of radiotherapy treat-ment field (Peripheral dose) using thermolumine-sent dosimeters. International Journal of Radiation Research. 2014;12:356.
12. [12] Yoon J, Heins D, Zhao X, Sanders M, Zhang R. Measurement and modeling of out-of-field doses from various advanced post-mastectomy radiother-apy techniques. Phys Med Biol. 2017;62:9039-53. doi: 10.1088/1361-6560/aa94b5. PubMed PMID: 29048329; PubMed Central PMCID: PMC5724526.
13. [13] Kourinou KM, Mazonakis M, Lyraraki E, Damilakis J. Photon-beam radiotherapy in pregnant patients: can the fetal dose be limited to 10 cGy or less? Phys Med. 2015;31(1):85-91.
14. [14] Al-Rahbi ZS, Ravichandran R, Binukumar JP, Davis CA, Satyapal N, Al-Mandhari Z. A Dosimetric Comparison of Radiotherapy Techniques in the Treatment of Carcinoma of Breast. Journal of Cancer Therapy. 2013; 4: 10-17.
15. [15] Howell RM, Scarboro SB, Kry SF, Yaldo DZ. Accuracy of out-of-field dose calculations by a commercial treatment planning system. Phys Med Biol. 2010;55(23):6999-7008.
16. [16] Mazonakis M, Varveris H, Damilakis J, Theoharopoulos N, Gourtsoyiannis N. Radiation dose to conceptus resulting from tangential breast irradiation. Int J Radiat Oncol. 2003;55(2):386-91.