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Dosimetric characteristics of VMAT plans with respect to a different increment of gantry angle size for Ca cervix

Published online by Cambridge University Press:  09 November 2020

Munirathinam Natraj Open the ORCID record for Munirathinam Natraj [Opens in a new window] ,
P. N. Pawaskar  and
Arun Chairmadurai
Munirathinam Natraj
Affiliation:
Department of Medical Physics, Centre for interdisciplinary Research, D.Y. Patil University, Kolhapur, India
P. N. Pawaskar*
Affiliation:
Department of Medical Physics, Centre for interdisciplinary Research, D.Y. Patil University, Kolhapur, India
Arun Chairmadurai
Affiliation:
Department of Radiation Oncology, Jaypee Hospital, Noida, India
*
Author for correspondence: Dr. Padmaja N. Pawaskar, Department of Medical Physics, Centre for interdisciplinary Research, D.Y. Patil University, Kolhapur, India. Tel: +91 9028074295. E-mail: [email protected]
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Abstract

Aim:

We have investigated the influence in volumetric-modulated arc therapy (VMAT) plans by a sequence of increment of gantry angle (IGA) in definitive radiotherapy treatment for cervical cancer. The plans are quantitatively analysed in terms of conformity index (CI), heterogeneity index (HI), dose–gradient index (DGI), target coverage (TC) by prescription dose, monitor unit (MU) usage, control points (CPs) and dose to organs.

Materials and Methods:

In this retrospective study, we selected 27 patients with cervical cancer having aged between 54 and 69. All the patients enrolled in this study were at T3N1M0 stage of cervical cancer. The prescription dose to planning target volume (PTV) was 50 Gy and was administered in 2 Gy/fraction through VMAT technique. VMAT plans were optimised by varying the parameter ‘IGA’ as 10, 20, 30 and 40°.

Results:

Homogenous dose distribution within PTV and TC by prescription dose was significantly enhanced (p < 0·05) with larger IGA. The difference between volume receiving 15 Gy (V15Gy) in bowel was up to 10% with larger IGA (30 and 40°) and V25Gy in femoral head was up to 3% with smaller IGA (10 and 20°). CPs were enhanced and MU usage was reduced with larger IGA (30 and 40°). IGA 40° had reduced the MU usage than IGA 30° but the CI and DGI were compromised due to large MLC field segments.

Conclusion:

This study recommends that the larger IGA could yield better results when the number of sectors is even, for a cervical cancer patient. However, more data from more patients need to be obtained and analysed to make this an evidence-based hypothesis.

Keywords

cervical cancerincrement of gantry anglesector anglevolumetric-modulated arc therapy
Type
Original Article
Information
Journal of Radiotherapy in Practice , Volume 21 , Issue 1 , March 2022 , pp. 92 - 96
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Copyright
© The Author(s), 2020. Published by Cambridge University Press

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References

Duan, J, Kim, RY, Elassal, S, Lin, HY, Shen, S. Conventional high-dose-rate brachytherapy with concomitant complementary IMRT boost: a novel approach for improving cervical tumor dose coverage. Int J Radiat Oncol Biol Phys 2008; 71 (3): 765–771.CrossRefGoogle ScholarPubMed
Georg, P, Georg, D, Hillbrand, M, Kirisits, C, Pötter, R. Factors influencing bowel sparing in intensity modulated whole pelvic radiotherapy for gynaecological malignancies. Radiother Oncol 2006; 80 (1): 19–26.CrossRefGoogle ScholarPubMed
Portelance, L, Chao, KS, Grigsby, PW, Bennet, H, Low, D. Intensity-modulated radiation therapy (IMRT) reduces small bowel, rectum, and bladder doses in patients with cervical cancer receiving pelvic and para-aortic irradiation. Int J Radiat Oncol Biol Phys 2001; 51 (1): 261–266.CrossRefGoogle ScholarPubMed
Otto, K. Volumetric modulated arc therapy: IMRT in a single gantry arc. Med Phys 2008; 35 (1): 310–317.CrossRefGoogle Scholar
Teoh, M, Clark, CH, Wood, K, Whitaker, S, Nisbet, A. Volumetric modulated arc therapy: a review of current literature and clinical use in practice. Br J Radiol 2011; 84 (1007): 967–996.CrossRefGoogle ScholarPubMed
Vanetti, E, Clivio, A, Nicolini, G, et al. Volumetric modulated arc radiotherapy for carcinomas of the oro-pharynx, hypo-pharynx and larynx: a treatment planning comparison with fixed field IMRT. Radiother Oncol 2009; 92 (1): 111–117.CrossRefGoogle ScholarPubMed
Palma, D, Vollans, E, James, K, et al. Volumetric modulated arc therapy for delivery of prostate radiotherapy: comparison with intensity-modulated radiotherapy and three-dimensional conformal radiotherapy. Int J Radiat Oncol Biol Phys 2008; 72 (4): 996–1001.CrossRefGoogle ScholarPubMed
Zhang, P, Happersett, L, Hunt, M, Jackson, A, Zelefsky, M, Mageras, G. Volumetric modulated arc therapy: planning and evaluation for prostate cancer cases. Int J Radiat Oncol Biol Phys 2010; 76 (5): 1456–1462.CrossRefGoogle ScholarPubMed
Yin, L, Wu, H, Gong, J, et al. Volumetric-modulated arc therapy vs. c-IMRT in esophageal cancer: a treatment planning comparison. World J Gastroenterol 2012; 18 (37): 5266–5275.Google ScholarPubMed
Abbas, AS, Moseley, D, Kassam, Z, Kim, SM, Cho, C. Volumetric-modulated arc therapy for the treatment of a large planning target volume in thoracic esophageal cancer. J Appl Clin Med Phys 2013; 14 (3): 192–202.CrossRefGoogle ScholarPubMed
Masi, L, Doro, R, Favuzza, V, Cipressi, S, Livi, L. Impact of plan parameters on the dosimetric accuracy of volumetric modulated arc therapy. Med Phys 2013; 40 (7): 071718.CrossRefGoogle ScholarPubMed
Treutwein, M, Hipp, M, Koelbl, O, Dobler, B. Searching standard parameters for volumetric modulated arc therapy (VMAT) of prostate cancer. Radiat Oncol 2012; 7: 108.CrossRefGoogle ScholarPubMed
Wang, Y, Chen, L, Zhu, F, Guo, W, Zhang, D, Sun, W. A study of minimum segment width parameter on VMAT plan quality, delivery accuracy, and efficiency for cervical cancer using Monaco TPS. J Appl Clin Med Phys 2018; 19 (5): 609–615.CrossRefGoogle ScholarPubMed
Nithya, L, Raj, NA, Rathinamuthu, S, Sharma, K, Pandey, MB. Influence of increment of gantry angle and number of arcs on esophageal volumetric modulated arc therapy planning in Monaco planning system: a planning study. J Med Phys 2014; 39 (4): 231–237.CrossRefGoogle ScholarPubMed
Chen, A, Li, Z, Chen, L, et al. The influence of increment of gantry on VMAT plan quality for cervical cancer. J Radiat Res Appl Sci 2019; 12 (1): 447–454.CrossRefGoogle Scholar
Edge, SB, Compton, CC. The American Joint Committee on Cancer: the 7th edition of the AJCC cancer staging manual and the future of TNM. Ann Surg Oncol 2010; 17 (6): 1471–1474.CrossRefGoogle ScholarPubMed
Lim, K, Small, W Jr, Portelance, L, et al. Consensus guidelines for delineation of clinical target volume for intensity-modulated pelvic radiotherapy for the definitive treatment of cervix cancer. Int J Radiat Oncol Biol Phys 2011; 79 (2): 348–355.CrossRefGoogle ScholarPubMed
Forrest, J, Presutti, J, Davidson, M, Hamilton, P, Kiss, A, Thomas, G. A dosimetric planning study comparing intensity-modulated radiotherapy with four-field conformal pelvic radiotherapy for the definitive treatment of cervical carcinoma. Clin Oncol (R Coll Radiol) 2012; 24 (4): e63–e70.CrossRefGoogle ScholarPubMed
Vrdoljak, E, Omrcen, T, Novaković, ZS, et al. Concomitant chemobrachyradiotherapy with ifosfamide and cisplatin followed by consolidation chemotherapy for women with locally advanced carcinoma of the uterine cervix--final results of a prospective phase II-study. Gynecol Oncol 2006; 103 (2): 494–499.CrossRefGoogle ScholarPubMed
Paddick, I. A simple scoring ratio to index the conformity of radiosurgical treatment plans. Technical note. J Neurosurg 2000; 93 (Suppl. 3): 219–222.CrossRefGoogle ScholarPubMed
R Development Core Team (2016). R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org. Accessed on 10th August 2020.Google Scholar