Tom 8, Nr 1 (2023)
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Opublikowany online: 2023-01-20

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Eksport do Mediów Społecznościowych

The prototype of EPID-based in vivo dose verification for VMAT treatments in patients with prostate cancer

Krzysztof Ślosarek1, Adam Gądek1, Marta Reudelsdorf-Ullmann1, Łukasz Sroka1, Janusz Winiecki23
Biuletyn Polskiego Towarzystwa Onkologicznego Nowotwory 2023;8(1):10-17.


Introduction. The volumetric modulated arc therapy technique (VMAT) is now widely used in radiotherapy. Verifica­tion of the dose delivered to the patient is performed prior to the treatment (pre-treatment mode). However, during the therapeutic session, only the patient’s position is verified and monitored. AnEPID’s (electronic portal imaging device) matrices can measure the intensity of radiation passing through the patient, but the calculation of the dose distribution from this measurement is limited due to the lack of reliable algorithms and software. Therefore, it seems promising to develop a method to estimate the dose in the patient’s body based on the measured calibration units (CU) values.

Material and methods. The material consists of 53 patients treated for prostate cancer with the VMAT technique. The CU signal is measured during the treatment and its value is then transformed according to the self-developed algorithm into a dose. This delivered dose is then compared with the planned dose in the target.

Results. The performed measurements of the CU and preliminary calculations indicate that it is possible to estimate the dose that the patient receives during the therapeutic session. The mean difference between the prescribed and me­asured dose values is less than 1%, however, there are differences of 17%.

Conclusions. The proposed method can be used in clinical practice for actual dose estimation. The uncertainty of the proposed method was estimated at 5%. In the event of differences above 10%, the treatment realization should be verified by additional tests including patient positioning and technical tests of accelerator, such as verification of kV and MV isocenter compatibility.

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  1. Slosarek K, Rembielak A, Cramb J, et al. Pitfalls in IMRT treatment planning with the CadPlan-Helios system. Med Dosim. 2004; 29(3): 179–183.
  2. Ślosarek K, Składowski K, Rembielak A, et al. Intensity modulated Radiation Therapy (IMRT) - description of the irradiation technique. Nowotwory. 2001; 51(6): 614–618.
  3. Składowski K, Grządziel M, Hutnik M, et al. Clinical principles of planning and implementation IMRT techniques in patients with head and neck cancer - part 1. Onkol Prakt Klin Edu. 2007; 3(5): 241–248.
  4. Ślosarek K, Bekman B, Wendykier J, et al. In silico assessment of the dosimetric quality of the novel, automated radiation treatment planning strategy for linac-based radiosurgery of multiple brain metastases and a comparison with robotic methods. Radiation Oncology. 2018; 13(1).
  5. Slosarek K, Zajusz A, Szlag M. Comparison of traditional and simultaneous IMRT boost technique basing on therapeutic gain calculation. Med Dosim. 2008; 33(4): 299–302.
  6. Ślosarek K. Techniki dynamiczne generujące zróżnicowany rozkład dawki promieniowania w radioterapii. Reports of Practical Oncology & Radiotherapy. 2003; 8: 9–83.
  7. Oelfke U, Bortfeld T. Inverse planning for x-ray rotation therapy: a general solution of the inverse problem. Phys Med Biol. 1999; 44(4): 1089–1104.
  8. Oelfke U, Bortfeld T. Intensity modulated radiotherapy with charged particle beams: Studies of inverse treatment planning for rotation therapy. Med Phys. 2000; 27(6): 1246–1257.
  9. Oelfke U, Bortfeld T. Inverse planning for photon and proton beams. Medical Dosimetry. 2001; 26(2): 113–124.
  10. Grills IS, Hugo G, Kestin LL, et al. Image-guided radiotherapy via daily online cone-beam CT substantially reduces margin requirements for stereotactic lung radiotherapy. Int J Radiat Oncol Biol Phys. 2008; 70(4): 1045–1056.
  11. van Elmpt W, Nijsten S, Petit S, et al. 3D in vivo dosimetry using megavoltage cone-beam CT and EPID dosimetry. Int J Radiat Oncol Biol Phys. 2009; 73(5): 1580–1587.
  12. van Elmpt W, Petit S, De Ruysscher D, et al. 3D dose delivery verification using repeated cone-beam imaging and EPID dosimetry for stereotactic body radiotherapy of non-small cell lung cancer. Radiother Oncol. 2010; 94(2).
  13. Maciejewski B, Drzewiecka B, Ślosarek K, et al. Physical and radiobiological rationale for advantages and limitations for Intensity-Modulated Radiotherapy (IMRT). Nowotwory. 2001; 51(4): 355–364.
  14. Olaciregui-Ruiz I, Rozendaal R, van Kranen S, et al. The effect of the choice of patient model on the performance of in vivo 3D EPID dosimetry to detect variations in patient position and anatomy. Med Phys. 2020; 47(1): 171–180.
  15. McDermont LN, Wedling M, Sonke JJ, et al. Replacing pretreatment verification with in vivo EPID dosimetry for prostate IMRT. Int J Radiation Oncology Biol Phys. 2007; 67(5): 1568–1577.
  16. McDermott LN, Wendling M, Nijkamp J, et al. 3D in vivo dose verification of entire hypo-fractionated IMRT treatments using an EPID and cone-beam CT. Radiother Oncol. 2008; 86(1): 35–42.
  17. van Zijtveld M, Dirkx MLP, de Boer HCJ, et al. 3D dose reconstruction for clinical evaluation of IMRT pretreatment verification with an EPID. Radiother Oncol. 2007; 82(2): 201–207.
  18. Li Y, Zhu J, Shi J, et al. Investigating the effectiveness of monitoring relevant variations during IMRT and VMAT treatments by EPID-based 3D in vivo verification performed using planning CTs. Comparative Study. 2019; 14(6).
  19. van Dam GMJ. Methods for in vivo dosimetry in external radiotherapy. ESTRO, Brussels 1994.
  20. IAEA. Development of Procedures for In Vivo Dosimetry in Radiotherapy. IAEA, Vienna 2013.
  21. Mijnheer B, Beddar S, Izewska J, et al. In vivo dosimetry in external beam radiotherapy. Med Phys. 2013; 40(7): 070903.
  22. Sekaran S, Arjunan M, Sarkar B, et al. Electronic portal imaging device-based three-dimensional volumetric dosimetry for intensity-modulated radiotherapy pretreatment quality assurance. J Med Phys. 2019; 44(3): 176.
  23. McDermott L. On radiotherapy dose verification with a flat-panel imager. Radiother Oncol. 2009; 92(1).
  24. Alber M, Broggi S, De Wagter C, et al. GUIDELINES FOR THE VERIFICATION OF IMRT. 2008.
  25. Alber M, Broggi S, De Wagter C, et al. Guidelines for the verification of IMRT. ESTRO, Brussels 2008.
  26. Zhang J, Li X, Lu M, et al. A method for in vivo treatment verification of IMRT and VMAT based on electronic portal imaging device. Radiation Oncology. 2021; 16(232).
  27. Winiecki J, Morgaś T, Majewska K, et al. The gamma evaluation method as a routine QA procedure of IMRT. Rep Pract Oncol Radiother. 2009; 14(5): 162–168.
  28. Winiecki J, Żurawski Z, Drzewiecka B, et al. Anatomy-corresponding method of IMRT verification . Rep Pract Oncol Radiother. 2011; 16(1): 1–9.
  29. Klimas A, Grządziel A, Plaza D, et al. EPID – a useful interfraction QC tool. Polish Journal of Medical Physics and Engineering. 2019; 25(4): 221–228.
  30. Ślosarek K. Verification of realization dynamic techniques in radiotherapy. Inżynier i Fizyk Medyczny. 2013; 2: 243–252.
  31. Miften M, Olch A, Mihailidis D, et al. Tolerance limits and methodologies for IMRT measurement-based verification QA: Recommendations of AAPM Task Group No. 218. Med Phys. 2018; 45(4): e53–e83.
  32. van Zijtveld M, Dirkx MLP, de Boer HCJ, et al. Dosimetric pre-treatment verification of IMRT using an EPID; clinical experience. Radiother Oncol. 2006; 81(2): 168–175.
  33. Herman M, Balter J, Jaffray D, et al. Clinical use of electronic portal imaging: Report of AAPM Radiation Therapy Committee Task Group 58. Medical Physics. 2001; 28(5): 712–737.
  34. Kupelian PA, Lee C, Langen KM, et al. Evaluation of image-guidance strategies in the treatment of localized prostate cancer. Int J Radiat Oncol Biol Phys. 2008; 70(4): 1151–1157.
  35. Ustawa Prawo Atomowe - Dziennik Ustaw 2021, poz.623.
  36. Obwieszczenie Ministra Zdrowia z dnia 3 kwietnia 2017 w sprawie warunków bezpiecznego stosowania promieniowania jonizującego dla wszystkich rodzajów ekspozycji medycznej 2017.
  37. Grządziel A, Smolińska B, Rutkowski R, et al. EPID dosimetry – configuration and pre-treatment IMRT verification. Reports of Practical Oncology & Radiotherapy. 2007; 12(6): 307–312.
  38. van Elmpt W, McDermott L, Nijsten S, et al. A literature review of electronic portal imaging for radiotherapy dosimetry. Radiother Oncol. 2008; 88(3): 289–309.
  39. Mans A, Wendling M, McDermott LN, et al. Catching errors within vivoEPID dosimetry. Med Phys. 2010; 37(6Part2): 2638–2644.
  40. Gabryś D, Kulik R, Trela K, et al. Dosimetric comparison of liver tumour radiotherapy in all respiratory phases and in one phase using 4DCT. Radiother Oncol. 2011; 100(3): 360–364.
  41. Woźniak G, Dolla Ł, Ślosarek K, et al. Dynamic-arc respiratory-gated stereotactic radiotherapy — technique presentation. Nowotwory. Journal of Oncology. 2018; 67(5): 297–300.
  42. Ślosarek K, Plaza D, Nas A, et al. Portal dosimetry in radiotherapy repeatability evaluation. J Appl Clin Med Phys. 2022; 22(1): 156–164.
  43. Baran M, Tabor Z, Kabat D, et al. Isodoses—a set theory-based patient-specific QA measure to compare planned and delivered isodose distributions in photon radiotherapy. Strahlenther Onkol. 2021.
  44. Kang S, Li J, Ma J, et al. Evaluation of  interfraction setup variations for  postmastectomy radiation therapy using EPID-based in vivo dosimetry. J Appl Clin Med Phys. 2019; 20(10): 43–52.
  45. Esposito M, Bruschi A, Bastiani P, et al. Characterization of EPID software for VMAT transit dosimetry. Australas Phys Eng Sci Med. 2018; 41(4): 1021–1027.
  46. Boutry C, Sors A, Fontaine J, et al. Technical Note: A simple algorithm to convert EPID gray values into absorbed dose to water without prior knowledge. Med Phys. 2017; 44(12): 6647–6653.
  47. Moustakis C, Ebrahimi Tazehmahalleh F, Elsayad K, et al. A novel approach to SBRT patient quality assurance using EPID-based real-time transit dosimetry : A step to QA with in vivo EPID dosimetry. Strahlenther Onkol. 2020; 196(2): 182–192.
  48. Slosarek K, Szlag M, Bekman B, et al. EPID in vivo dosimetry in RapidArc technique. Rep Pract Oncol Radiother. 2010; 15(1): 8–14.
  49. Wendling M, Louwe R, McDermott L, et al. Accurate two-dimensional IMRT verification using a back-projection EPID dosimetry method. Med Phys. 2006; 33(2): 259–273.
  50. Rose M, Tirpak L, Casteren KV, et al. Multi‐institution validation of a new high spatial resolution diode array for SRS and SBRT plan pretreatment quality assurance. Med Phys. 2020; 47(7): 3153–3164.
  51. Kruszyna-Mochalska M. EPID-based daily verification of reproducibility of patients' irradiation with IMRT plans. Rep Pract Oncol Radiother. 2018; 23(5): 309–314.
  52. Mijnheer B, Olaciregui-Ruiz I, Rozendaal R. 3D EPID-based in vivo dosimetry for IMRT and VMAT. Journal of Physics: Conference Series. 2013.
  53. Olaciregui‐Ruiz I, Vivas‐Maiques B, Kaas J, et al. Transit and non‐transit 3D EPID dosimetry versus detector arrays for patient specific QA. J Appl Clin Med Phys. 2019; 20(6): 79–90.
  54. Osewski W, Dolla L, Radwan M, et al. Clinical examples of 3D dose distribution reconstruction, based on the actual MLC leaves movement, for dynamic treatment techniques. Rep Pract Oncol Radiother. 2014; 19(6): 420–427.
  55. Kalet I, Kennedy D. A comparison of two radiological path length algorithms. International Journal of Radiation Oncology*Biology*Physics. 1987; 13(12): 1957–1959.

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