DOSIMETRIC COMPARISON OF FLATTENING FILTER-FREE BEAMS WITH THE FLATTENED BEAM OF 6 MV AND 10 MV PHOTON FOR VOLUMETRIC MODULATED ARC THERAPY IN CERVIX CARCINOMA PLANS

Kamalnath J, Jitendra Nigam, Silambarasan N S, Navitha S, Piyush Kumar

Abstract


Aim: To dosimetrically compare Volumetric modulated arc therapy (VMAT) plan of attening lter-free beam (FFF) and attened beam (FB) for 6
MV and 10 MV photon beams planned for cervix carcinoma cases. A total number of thirty three cervix carcinoma caseMaterials and Methods: s
treated in 2021 and 2022 were selected retrospectively. The VMAT plans were prepared using Eclipse™ 13.6v Treatment Planning System.
Prescription used for planning was 50 Gy in 25 Fraction. 16 patients planned with 6MV and 6MV-FFF beam. Remaining 17 patients were planned
with 10MV and 10MV-FFF beam. Two full arcs with no avoidance sector were used in all plans. For inverse planning optimization Progressive
Resolution Optimizer (PRO) with 2.5 mm grid size used and for dose calculation, Analytical Anisotropic Algorithm (AAA) was used. During
optimization, dose objectives of PTV and OAR are kept constant between two plans. Priorities and NTO also maintained similar between two set of
plans. Optimization and dose calculation steps are repeated sometimes to achieve clinically acceptable plan. The tools used to evaluate the plans
are; Target Conformity Index (CI), Homogeneity Index (HI), dose to OARs, mean Normal tissue integral Dose (NTID), total monitor units (MUs)
and Beam on Time (BOT) were analyzed. For statistical analysis, student t-test method was used. Result: From the results it is observed that plans
created by FB and FFF beams are clinically acceptable. CI, HI in PTV coverage, normal tissue volume receiving low doses, MU and BOT are
showing signicant results. Mean NTID is found to be signicant only in 10MV beams. FFF VMAT plans does not shows any signicant
dosimetric differences over FB VMAT plans in terms of OAR mean dose in cervix carcinoma cases. However 10 MV-FB shows better rectum
sparing than 10 MV-FFF. Conclusion: FB can be used for VMAT plans when conformity and homogeneity Index are concerned. FFF beams
VMAT plan can be used for patient those who have chances of secondary malignancies since it reduces volume receiving low doses.


Keywords


Flattening lter-free beam (FFF), Flattened beam (FB), Volumetric modulated arc therapy (VMAT), Normal tissue integral Dose (NTID), Low dose volumes.

Full Text:

PDF

References


Georg D, Knöös T, McClean B. Current status and future perspective of attening lter

free photon beams. Med Phys. 2011;38(3):1280–93.

Flattening lter free in intensity-modulated radiotherapy (IMRT) – Theoretical

modeling with delivery efciency analysis - Ma - 2019 - Medical Physics - Wiley Online

Library [Internet]. [cited 2022 Oct 31]. Available from: https://aapm. onlinelibrary.

wiley.com/doi/epdf/10.1002/mp.13267

Unattened photon beams from the standard attening lter free accelerators for

radiotherapy: Advantages, limitations and challenges Sharma SD - J Med Phys

[Internet]. [cited 2022 Oct 31]. Available from: https://www .jmp.org. in/article.

asp?issn=0971-6203;year=2011; volume=36; issue=3; spage=123;epage=125;

aulast=Sharma

Cashmore J. The characterization of unattened photon beams from a 6 MV linear

accelerator. Phys Med Biol. 2008 Apr 7;53(7):1933–46.

Sf K, U T, F P, On V, M S, M G, et al. Reduced neutron production through use of a

attening-lter-free accelerator. Int J RadiatOncolBiolPhys [Internet]. 2007 Jul 15

[cited 2022 Oct 31];68(4). Available from: https://pubmed.ncbi.nlm.nih.gov/17637397/

ICRU [Internet]. [cited 2021 Mar 29]. Available from: https://www.icru.org/

ICRU Report 50—Prescribing, Recording and Reporting Photon Beam Therapy - Jones

- 1994 - Medical Physics - Wiley Online Library [Internet]. [cited 2022 Oct 31].

Available from: https://aapm.onlinelibrary.wiley.com/doi/10.1118/1.597396

Hodapp N. The ICRU Report 83: prescribing, recording and reporting photon-beam

intensity-modulated radiation therapy (IMRT). StrahlentherOnkol Organ

DtschRöntgenges Al. 2012 Jan 1;188:97–9.

Protocol [Internet]. [cited 2022 Oct 31]. Available from: https://www.nrgoncology. org/

Clinical-Trials/Protocol/rtog-1203?lter=rtog-1203

Paddick I. A simple scoring ratio to index the conformity of radiosurgical treatment

plans. Technical note. J Neurosurg. 2000 Dec;93Suppl 3:219–22.

D'Arienzo M, Masciullo SG, de Sanctis V, Osti MF, Chiacchiararelli L, Enrici RM.

Integral dose and radiation-induced secondary malignancies: comparison between

stereotactic body radiation therapy and three-dimensional conformal radiotherapy. Int J

Environ Res Public Health. 2012 Nov 19;9(11):4223–40.

Khan FM. The physics of radiation therapy. 3rd ed. Philadelphia: Lippincott Williams &

Wilkins; 2003. 212–213 p.

Hermanto U, Frija EK, Lii MJ, Chang EL, Mahajan A, Woo SY. Intensity-modulated

radiotherapy (IMRT) and conventional three-dimensional conformal radiotherapy for

high-grade gliomas: does IMRT increase the integral dose to normal brain? Int J

RadiatOncolBiol Phys. 2007 Mar 15;67(4):1135–44.

D'Souza WD, Rosen II. Nontumor integral dose variation in conventional radiotherapy

treatment planning. Med Phys. 2003 Aug;30(8):2065–71.

Mock U, Georg D, Bogner J, Auberger T, Pötter R. Treatment planning comparison of

conventional, 3D conformal, and intensity-modulated photon (IMRT) and proton

therapy for paranasal sinus carcinoma. Int J RadiatOncolBiol Phys. 2004 Jan

;58(1):147–54.

Pirzkall A, Carol M, Lohr F, Höss A, Wannenmacher M, Debus J. Comparison of

intensity-modulated radiotherapy with conventional conformal radiotherapy for

complex-shaped tumors. Int J RadiatOncolBiol Phys. 2000 Dec 1;48(5):1371–80.

Lian J, Mackenzie M, Joseph K, Pervez N, Dundas G, Urtasun R, et al. Assessment of

extended-eld radiotherapy for stage IIIC endometrial cancer using three-dimensional

conformal radiotherapy, intensity-modulated radiotherapy, and helical tomotherapy. Int

J RadiatOncolBiol Phys. 2008 Mar 1;70(3):935–43.

Hall EJ. Intensity-modulated radiation therapy, protons, and the risk of second cancers.

Int J RadiatOncolBiol Phys. 2006 May 1;65(1):1–7.

Report No. 116 – Limitation of Exposure to Ionizing Radiation (Supersedes NCRP

Report No. 91) (1993) - NCRP | Bethesda, MD [Internet]. 2018 [cited 2022 Nov 12].

Available from: https://ncrponline.org/shop/reports/report-no-116-limitation-ofexposure-

to-ionizing-radiation-supersedes-ncrp-report-no-91-1993/

Diallo I, Haddy N, Adjadj E, Samand A, Quiniou E, Chavaudra J, et al. Frequency

distribution of second solid cancer locations in relation to the irradiated volume among

patients treated for childhood cancer. Int J RadiatOncolBiol Phys. 2009 Jul

;74(3):876–83.

Hall EJ, Wuu CS. Radiation-induced second cancers: the impact of 3D-CRT and IMRT.

Int J RadiatOncol. 2003 May 1;56(1):83–8.

Chaturvedi AK, Engels EA, Gilbert ES, Chen BE, Storm H, Lynch CF, et al. Second

Cancers Among 104760 Survivors of Cervical Cancer: Evaluation of Long-Term Risk.

JNCI J Natl Cancer Inst. 2007 Nov 7;99(21):1634–43.

Nicolini G, Ghosh-Laskar S, Shrivastava SK, Banerjee S, Chaudhary S, Agarwal JP, et

al. Volumetric modulation arc radiotherapy with attening lter-free beams compared

with static gantry IMRT and 3D conformal radiotherapy for advanced esophageal

cancer: a feasibility study. Int J RadiatOncolBiol Phys. 2012 Oct 1;84(2):553–60.

Yan Y, Yadav P, Bassetti M, Du K, Saenz D, Harari P, et al. Dosimetric differences in

attened and attening lter-free beam treatment plans. J Med Phys. 2016

Jun;41(2):92–9.

Comparative Evaluation of a 6MV Flattened Beam and a Flattening Filter Free Beam for

Carcinoma of Cervix – IMRT Planning Study - PubMed [Internet]. [cited 2022 Oct 31].

Available from: https://pubmed.ncbi.nlm.nih.gov/29580032/

Cakir A, Akgun Z, KaytanSaglam E. Dosimetric inuence of Flattening Filter (FF) and

Flattening Filter Free (FFF) 6 and 10 MV photon beams on Volumetric Modulated Arc

Therapy (VMAT) planning in case of prostate carcinoma. 2019 May 13;

Fu G, Li M, Song Y, Dai J. A dosimetric evaluation of attening lter-free volumetric

modulated arc therapy in nasopharyngeal carcinoma. J Med Phys. 2014 Jul 1;39(3):150.

Zhuang M, Huang L, Zhu D, Peng X, Lin Z. Reirradiation of nasopharyngeal carcinoma

focusing on volumetric modulated arcs with attening lter-free beams. Br J Radiol.

Aug;88(1052):20140837.

Bhushan M, Yadav G, Tripathi D, Kumar L, Kishore V, Dewan A, et al. Dosimetric

Analysis of Unattened (FFFB) and Flattened (FB) Photon Beam Energy for Gastric

Cancers Using IMRT and VMAT—a Comparative Study. J Gastrointest Cancer. 2019

Sep 1;50(3):408–19.

Spruijt KH, Dahele M, Cuijpers JP, Jeulink M, Rietveld D, Slotman BJ, et al. Flattening

lter free vs attened beams for breast irradiation. Int J RadiatOncolBiol Phys. 2013 Feb

;85(2):506–13.

Zhuang M, Zhang T, Chen Z, Lin Z, Li D, Peng X, et al. Advanced nasopharyngeal

carcinoma radiotherapy with volumetric modulated arcs and the potential role of

attening lter-free beams. RadiatOncol. 2013 Dec;8(1):1–9.

Manna S, Kombathula SH, Gayen S, Varshney S, Pareek P. Dosimetric impact of FFF

over FF beam using VMAT for brain neoplasms treated with radiotherapy. Pol J Med

Phys Eng. 2021 Sep 1;27(3):191–9.


Refbacks

  • There are currently no refbacks.