DOSIMETRIC COMPARISON OF PRE-SELECTED BEAM ORIENTATION AND BEAM ANGLE OPTIMIZATION IN INTENSITY MODULATED RADIATION THERAPY PLANS FOR NASOPHARYNGEAL CARCINOMA.

Anjana A K, Silambarasan N S, Jitendra Nigam, Navitha S, Piyush Kumar

Abstract


Purpose: This study is intended to verify and analyze the dosimetric impact of Pre selected beam orientation (PSBO) and Beam angle optimization
(BAO) in IMRT for Nasopharyngeal Carcinoma. Twenty patients of Nasopharyngeal carcinoma treated with IMRMaterials and Methods: T
Plans were recruited for this retrospective study. Varian Medical systems treatment planning systems (TPS), Eclipse of version 13.6 were used for
planning. All twenty patients were treated with IMRT plan created by PSBO while choosing beam angle. Another plan using BAO used for
choosing beam angles followed by PRO optimization for inverse planning were created. Objectives of PTV and OARs are maintained constant in
both the plans. Statistical analyses of both the plans were performed using parameters; Paddick conformity index (PCI), Homogeneity index (HI),
Dose delivered to OAR and Delivered MU. The statistical data were analyzed by Student t test. Result: In this study, out of twenty patients,
seventeen patients BAO were valid for inverse planning optimization. For three patients beam angles chosen by BAO were invalid. And the
dosimetric comparison of seventeen patients between BAO and PSBO was showing similar results except for MU. The p value obtained for all the
parameters except MU, were >0.05. On taking into consideration of delivered MU, PSBO has lesser MU than BAO and are statistically signicant.
Conclusion: On reviewing the results, it is concluded that both BAO and PSBO are clinically acceptable. But on concerning the delivered MU,
PSBO seems to be better method than BAO. Also, it should be taken into account that three of the plans have been failed to optimize in BAO, since
the beam angles suggested in this BAO method does not account the limitations of machine. It shows the advantage of PSBO over BAO. Hence, we
can conclude that PSBO is a better method in selection of beam angles in Nasopharyngeal Carcinoma cases.


Keywords


Intensity Modulated Radiation Therapy (IMRT), Beam angle optimization (BAO), Pre selected beam orientation (PSBO).

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References


Intensity Modulated Radiation Therapy Collaborative Working Group. Intensitymodulated

radiotherapy: current status and issues of interest. Int J Radiat Oncol Biol

Phys. 2001 Nov 15;51(4):880-914. doi: 10.1016/s0360-3016(01)01749-7. PMID:

Shukla AK, Kumar S, Sandhu IS, Oinam AS, Singh R, Kapoor R. Dosimetric study of

beam angle optimization in intensity-modulated radiation therapy planning. J Cancer

Res Ther. 2016 Apr-Jun;12(2):1045-9. doi: 10.4103/0973-1482.157324. PMID:

Taylor A, Powell ME. Intensity-modulated radiotherapy--what is it? Cancer Imaging.

Mar 26;4(2):68-73. doi: 10.1102/1470-7330.2004.0003. PMID: 18250011;

PMCID: PMC1434586.

Taşkın, Z. & Smith, J. & Romeijn, H. & Dempsey, James. (2010). Optimal Multileaf

Collimator Leaf Sequencing in IMRT Treatment Planning. Operations Research. 58.

-690. 10.1287/opre.1090.0759.

Mock U, Georg D, Bogner J, et al. Treatment planning comparison of conventional, 3D

conformal, and intensitymodulated photon (IMRT) and proton therapy for paranasal

sinus carcinoma. Int J Radiat Oncol Biol Phys 2004;58: 147–154.

Li, Y. (2018). Prior Knowledge Helps Improve Beam Angle Optimization Efciency in

Radiotherapy Planning. arXiv. https://doi.org/10.48550/arXiv.1811.01834

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

plans. Technicalnote.JNeurosurg.2000Dec;93 Suppl 3:219-22. doi: 10.3171/jns. 2000.

supplement. PMID: 11143252.

Paddick I, Lippitz B. A simple dose gradient measurement tool to complement the

conformityindex.JNeurosurg. 2006 Dec;105 Suppl:194-201. doi: 10.3171/sup.2006.

7.194. PMID: 18503356.

Kataria T, Sharma K, Subramani V, Karrthick KP, Bisht SS. Homogeneity Index: An

objective tool for assessment of conformal radiation treatments. J Med Phys.

;37(4):207- 213. doi:10.4103/0971-6203.103606

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.

An introduction to t-tests, Published on January 31, 2020 by Rebecca Bevans. Revised

on December 14, 2020.

Srivastava SP, Das IJ, Kumar A, Johnstone PA. Dosimetric comparison of manual and

beam angle optimization of gantry angles in IMRT. Med Dosim. 2011

Autumn;36(3):313-6. doi: 10.1016/j.meddos.2010.07.001. Epub 2010 Sep 3. PMID:

Liu HH, Jauregui M, Zhang X, Wang X, Dong L, PSBOhan R. Beam angle optimization

and reduction for intensity-modulated radiation therapy of non-small-cell lung cancers.

Int J Radiat Oncol Biol Phys. 2006 Jun 1;65(2):561-72. doi: 10.1016/j.ijrobp. 2006.01.

PMID: 16690438

Ventura, T., Lopes, M.d.C., Rocha, H., da Costa Ferreira, B., Dias, J. (2020). Advantage

of Beam Angle Optimization in Head-and-Neck IMRT: Patient Specic Analysis. In:

Henriques, J., Neves, N., de Carvalho, P. (eds) XV Mediterranean Conference on

Medical and Biological Engineering and Computing – MEDICON 2019. MEDICON

IFMBE Proceedings, vol 76. Springer, Cham. https://doi.org/10.1007/978-3-030-

-8_153

Wang, Xiaochun & Zhang, Xiaodong & Dong, Lei & Liu, Helen & Gillin, Michael &

Ahamad, Anesa & Ang, Kian & Mohan, Radhe. (2005). Effectiveness of noncoplanar

IMRT planning using a parallelized multiresolution beam angle optimization method for

paranasal sinus carcinoma. International journal of radiation oncology, biology, physics.

594-601. 10.1016/j.ijrobp.2005.06.006.

Leung WS, Wu VWC, Liu CYW, Cheng ACK. A dosimetric comparison of the use of

equally spaced beam (ESB), beam angle optimization (BAO), and volumetric

modulated arc therapy (VMAT) in head and neck cancers treated by intensity modulated

radiotherapy. J Appl Clin Med Phys. 2019 Nov;20(11):121-130. doi:

1002/acm2.12748. Epub 2019 Oct 8. PMID: 31593367; PMCID: PMC6839392.

Rocha, Humberto & Matos Dias, Joana & Ventura, Tiago & Ferreira, Brigida & Lopes,

Maria do Carmo. (2016). A derivative-free multistart framework for an automated

noncoplanar beam angle optimization in IMRT. Medical Physics. 43. 5514-5526.

1118/1.4962477.

Wang X, Zhang X, Dong L, Liu H, Wu Q, Mohan R. Development of methods for beam

angle optimization for IMRT using an accelerated exhaustive search strategy. Int J

Radiat Oncol Biol Phys. 2004 Nov 15;60(4):1325-37. doi: 10.1016/j. ijrobp.2004.06.

PMID: 15519806.

Pugachev A, Xing L. Incorporating prior knowledge into beam orientation optimization

in IMRT. Int J Radiat Oncol Biol Phys. 2002 Dec 1;54(5):1565-74. doi: 10.1016/s0360-

(02)03917-2. PMID: 12459386.


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