Evaluating the Dosimetric Characteristics of Radiation Therapies according to Head Elevation Angle for Head and Neck Tumors

Geum-Seong Cheon; Seong-Hee Kang; Dong-Su Kim; Tae-Ho Kim; Tae-Suk Suh

doi:10.14316/pmp.2016.27.1.14

Journal List > Prog Med Phys > v.27(1) > 1098508

Go to TopGo to Top Go to BottomGo to Bottom

TOOLS

Cheon, Kang, Kim, Kim, and Suh: Evaluating the Dosimetric Characteristics of Radiation Therapies according to Head Elevation Angle for Head and Neck Tumors

Original Article

Progress in Medical Physics 2016;27(1):14-24.

Published online: 4 March 2016

DOI: https://doi.org/10.14316/pmp.2016.27.1.14

Evaluating the Dosimetric Characteristics of Radiation Therapies according to Head Elevation Angle for Head and Neck Tumors

Geum-Seong Cheon^*,^†, Seong-Hee Kang^†, Dong-Su Kim^†, Tae-Ho Kim^†, Tae-Suk Suh^†,

^*Department of Radiation Oncology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea

^†Department of Biomedical Engineering and Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul, Korea

Correspondence: Tae-Suk Suh (suhsanta@catholic.ac.kr) Tel: 82-2-2258-7232, Fax:82-2-2258-7506

Received 29 February 2016 Revised 15 March 2016 Accepted 18 March 2016

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Since the head and neck region is densely located with organs at risk (OAR), OAR-sparing is an important issue in the treatment of head and neck cancers. This study— in which different treatment plans were performed varying the head tilt angle on brain tumor patients— investigates the optimal head elevation angle for sparing normal organs (e.g. the hippocampus) and further compares the dosimetric characteristics of different types of radiation equipment. we performed 3D conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and tomotherapy on 10 patients with brain tumors in the frontal lobe while varying the head tilt angle of patients to analyze the dosimetric characteristics of different therapy methods. In each treatment plan, 95% of the tumor volume was irradiated with a dose of 40 Gy in 10 fractions. The step and shoot technique with nine beams was used for IMRT, and the same prescription dose was delivered to the tumor volume for the 3D-CRT and tomotherapy plans. The homogeneity index, conformity index, and normal tissue complication probability (NTCP) were calculated. At a head elevation angle of 30 ^o, conformity of the isodose curve to the target increased on average by 53%, 8%, and 5.4%. In 3D-CRT, the maximum dose received by the brain stem decreased at 15 ^o, 30 ^o, and 40 ^o, compared to that observed at 0 ^o. The NTCP value of the hippocampus observed in each modality was the highest at a head and neck angle of 0 ^o and the lowest at 30 ^o. This study demonstrates that the elevation of the patients' head tilt angle in radiation therapy improves the target region's homogeneity of dose distribution by increasing the tumor control rate and conformity of the isodose curve to the target. Moreover, the study shows that the elevation of the head tilt angle lowers the NTCP by separating the tumor volume from the normal tissues, which helps spare OARs and reduce the delivered dose to the hippocampus.

Keywords: Head&Neck Cancer, Hippocampus, Head elevation angle, Treatment planning

References

1. Lee SW, Back GM, Yi BY, et al. Preliminaryresultsofa phaseI-IIstudyofsimultaneousmodulatedacceleratedradio-therapyfornondisseminatednasopharyngealcarcinoma. Int.J. Radiat.Oncol.Biol.Phys. 65:152–160. 2006.

2. Shiau AC, Lai PL, Liang JA, et al. Dosimetricverification ofsurfaceandsuperficialdosesforheadandneckIMRTwith differentPTVshrinkagemargins.Med.Phys. 38:1435–1443. 2011.

3. Pezner RD, Archambeau JO. Braintoleranceunit: Ameth-odtoestimateriskofradiationbraininjuryforvariousdose schedules.Int.J.Radiat.Oncol.Biol.Phys. 7:397–402. 1981.

4. Milano MT, Constine LS, et al. NormalTissueTolerance Dose Metrics for Radiation The rapyof Major Organs. Semin. Radiat.Oncol. 17:131–140. 2007.

5. Sahgal A, Barani LJ, Jr JN, et al. PrescriptionDose GuidelineBasedonPhysicalCriterionforMultipleMetastatic BrainTumorsTreatedWithStereotacticRadiosurgery.Int.J. Radiat.Oncol.Biol.Phys. 78:605–608. 2010.

6. Jeraj R, Mackie TR, Balog J, et al. Radiationcharacter-isticsofhelicaltomotherapy.Med.Phys. 31:396–404. 2004.

7. Kan MW, Cheung JY, Leung LH, et al. Theaccuracyof dosecalculationsbyanisotropicanalyticalalgorithmsforstereo-tacticradiotherapyinnasopharyngealcarcinoma.Phys.Med. Biol. 56:397–413. 2011.

8. Park SH, Park HC, Oh DH, et al. Multi-institutional ComparisonofIntensitymodulatedradiationTherapy(IMRT) PlanningstrategiesandPlanningResultsforNasopharyngeal Cancer.J.Korean.Med.Sci. 24:pp.248–255. 2009.

9. Mackie TR, Balog J, Ruchala K, et al. Tomotherapy. Semin.Radiat.Oncol. 9:pp.108–117. (. 1999.

10. Marsh JC, Godbole R, Diaz AZ, et al. Sparing of the hippocampus, limbic circuitandneural stem cell compartment during partial brain radio therapy for glioma:: Adosimetricfeasibility study.J.Med.Imag.Radiat.On. 55:pp.442–449. 2011.

11. Huang D, Xia P, Akazawa P, et al. Comparisonoftreatmentusingintensity-modulatedradiotherapyandthree-dimen-sionalconformalradiotherapyforparanasalsinuscarcinoma,Int. J.Radiat.Oncol.Biol.Phys.56,No. 1:pp.158–168. (. 2003.

12. Niroomand RA, Razavi R, Thobejane S, et al. Radiation doseperturbationattissue-titaniumdentalinterfacesinhead andneckcancerpatients.Int.J.Radiat.Oncol.Biol.Phys. 34:475–480. 1996.

13. Choi JY, Won YJ, Park JY, et al. Developmentofa ThermoplasticOralCompensatorforImprovingDoseUniformity inRadiationTherapyforHeadandNeckCancer.Progressin MedicalPhysics. 23:269–278. 2012.

14. Vesna Prokic, Nicole Wiedenmann, Fels F, et al. Whole BrainIrradiationWithHippocampalSparingandDoseEscalation onMultipleBrainMetastases: APlanningStudyonTreatment Concepts.Int.J.Radiat.Oncol.Biol.Phys.85,No. 1:pp.264–270. (. 2013.

15. Vinai Gondi, Tolakanahalli R, Mehta MP, et al. Hippo-campal-SparingWhole-BrainRadiotherapy: A “How-To” TechniqueUsingHelicalTomotherapyandLinearAccelerator-BasedIntensity-ModulatedRadiotherapy.Int.J.Radiat.Oncol. Biol.Phys. 78:,No.(4):pp.1244–1252. (. 2010.

16. Wang X, Zhang X, Dong L, et al. Effectivenessofnon-coplanarIMRTplanningusingaparallelizedmultiresolution beamangleoptimizationmethodforparanasalsinuscarcinoma. Int.J.Radiat.Oncol.Biol.Phys. 63:594–601. 2005.

17. Siglin J, Champ CE, Vakhnenko Y, et al. Optimizingpatientpositioningforintensitymodulatedradiationtherapyinhip-pocampal-sparingwholebrainradiationtherapy. Pract. Radiat. Oncol. 4:378–383. 2014.

18. Joseph KJ, Syme A, Small C, et al. Atreatmentplanning studycomparinghelicaltomotherapywithintensity-modulated radiotherapyforthetreatmentofanalcancer.Radiother.Oncol. 94:pp.60–66. 2010.

19. Lee FK, Yip CW, Cheung nkie Chun-hung, et al. Dosimetricdifferenceamongst3techniques:: TomoTherapy, sliding-windowintensity-modulatedradiotherapy(IMRT),and RapidArcradiotherapyinthetreatmentoflate-stagenasophar-yngealcarcinoma(NPC).Med.Dosim. 39:pp.44–49. 2014.

20. Alber M, Nusslin F. Optimizationofintensitymodulatedra-diotherapyunder constraintsforstaticanddynamicMLC delivery.Phys.Med.Biol. 46:3229–3239. 2001.

21. Chui H, Rangarajan A. Anewpointmatchingalgorithmfor non-rigidregistration.Comp.Vis.ImageUnd. 89:pp.114–141. 2003.

22. Semenenko VA. Lyman-Kutcher-BurmanNTCPmodel parametersforradiationpneumonitisandxerostomiabasedon combinedanalysisofpublishedclinicaldata.Phys.Med.Biol. 53:737–55. 2008.

23. G Luxton G, Keall PJ, King CR. Anewformulafornormal tissuecomplicationprobability(NTCP)asafunctionofequiv-alentuniformdose(EUD).Phys.Med.Biol. 53:23–36. 2008.

24. Kutcher GJ, Burman C, Brewster L, et al. Histogramre-ductionmethodforcalculatingcomplicationprobabilitiesfor three-dimensionaltreatmentplanningevaluations.Int.J.Radiat. Oncol.Biol.Phys. 21:137–146. 1991.

25. Makrs LB, Yorke ED, Jackson A, et al. UseofNormal TissueComplicationProbabilityModelsintheClinic.Int.J. Radiat.Oncol.Biol.Phys. 76:S10–S19. 2010.

26. Emami B, Lyman J, Brown A, et al. Toleranceofnormal tissuetotherapeuticirradiation.Int.J.Radiat.Oncol.Biol.Phys. 21:109–122. 1991.

Fig. 1.

(a) RANDO Phantom and head-board, (b) RANDO Phantom and head-board scan with CT simulator.

Fig. 2.

Delineation of the hippocampus in MRI (Orange Line: Hippocampus, Light green Line: Hippocampus 3 mm expansion).

Fig. 3.

Dose distribution among the 3 different treatment techniques (a) 3D-CRT, (b) Linac-IMRT and (c) Tomotherapy.

Fig. 4.

DVH (Dose Volume Histogram) among the 3 different treatment techniques. (a) 0 degree, (b) 30 degree.

Fig. 5.

Difference of received dose of OAR among the tilting angle. (a) 0 degree, (b) 30 degree.

Table 1.

Characteristics of 10 patients participated in the study.

Pt No	연령/성별	PTV Volume (cm 3)	진단명(Dx)	치료부위(Tx. Site)
1	61/F	60.2	Glioblastoma, Grade IV	Rt. frontal lobe
2	56/F	54.13	Glioblastoma, corpus callosum, Grade IV	Lt. frontal lobe
3	62/M	59.4	Anaplastic meningioma, (grade III by WHO)	Lt. frontal lobe
4	46/F	53.2	Anaplastic astrocytoma	Rt. frontal lobe
5	55/M	57.2	Glioblastoma	Lt. frontal lobe
6	60/F	59.5	Glioblastoma	Lt. frontal lobe
7	82/M	50.5	Rec.atypical meningioma	Rt. frontal lobe
8	58/M	51.2	Anaplastic Ependymoma(grade III by WHO)	Lt. frontal lobe
9	37/F	53.5	Rec. Oligoastrocytoma of brain (grade II by WHO)	Lt. frontal lobe
10	58/F	57.0	Anaplastic astrocytoma (grade III by WHO)	Lt. frontal lobe

Table 2.

Comparison of the dose received by tumor in different radiation therapies with varied head elevation angles.

	3D-CRT				Linac-IMRT				Tomotherapy
	0^o	15^o	30^o	40^o	0^o	15^o	30^o	40^o	0^o	15^o	30^o	40^o
CI	1.70±0.12	1.61±0.22	1.11±0.02	1.51±0.04	1.21±0.14	1.18±0.23	1.12±0.04	1.19±0.21	1.13±0.04	1.08±0.05	1.07±0.06	1.09±0.01
HI	0.11±0.05	0.09±0.09	0.08±0.10	0.09±0.16	0.05±0.45	0.04±0.32	0.03±0.28	0.03±0.48	0.04±0.32	0.04±0.44	0.03±0.58	0.09±0.35
PTV Mea	n 40.80±0.80	41.20±1.01	40.30±0.93	41.20±0.71	40.60±0.52	42.90±0.82	40.60±0.51	41.10±0.61	40.80±0.72	41.40±0.63	40.90±0.82	40.90±1.02
dose (Gy	y)

CI: Conformity index, HI: Homogeneity index.

Table 3.

Comparison of the dose received by normal organs in different radiation therapies with varied head elevation angles.

	3D-CRT				Linac-IMRT				Tomotherapy
	0^o	15^o	30^o	40^o	0^o	15^o	30^o	40^o	0^o	15^o	30^o	40^o
Max (Brain stem)	32.00±2.50	28.90±3.10	23.70±1.80	24.80±3.20	33.00±2.20	23.30±2.70	19.10±3.20	31.60±2.00	25.20±3.00	22.50±2.10	21.40±1.20	24.20±3.40
(Gy)
Max (Lt lens)	9.50±3.90	8.70±2.50	4.10±1.40	7.20±1.80	4.50±1.50	3.80±1.20	2.50±0.80	3.50±0.10	3.30±0.20	2.70±1.70	2.50±0.70	3.20±0.90
(Gy)
Max (Rt lens)	6.50±1.20	8.90±2.20	5.20±2.50	7.80±1.80	5.30±1.20	4.30±2.10	3.50±1.80	4.20±0.70	3.00±0.50	2.50±0.70	1.80±0.40	2.20±0.70
(Gy)
Mean (Lt Orbit)	13.10±1.20	10.20±1.10	8.90±0.80	10.50±0.70	6.50±0.50	5.50±0.40	4.10±0.70	5.90±0.50	5.70±0.60	5.10±0.50	4.50±0.40	5.10±0.30
(Gy)
Mean (Rt Orbit)	12.80±0.40	9.90±0.40	6.50±0.70	10.50±0.80	6.60±0.90	5.80±0.20	3.20±0.40	4.80±0.50	6.20±0.70	5.80±0.60	4.30±0.80	4.80±0.50
(Gy)

Table 4.

Comparison of the dose received by the hippocampus with varied head elevation angles.

Hippocampus dose (Gy)
Patient		0 ^o	15 ^o	30 ^o	40 ^o	0 ^o	15 ^o	30 ^o	40 ^o	0 ^o	15 ^o	30 ^o	40 ^o
Patient		3D-CRT				Linac-IMRT				Tomotherapy
1	Max dose	34.0	30.0	17.4	27.2	22.0	19.6	14.7	19.3	20.0	16.0	12.0	18.0
	D100%	7.0	8.0	7.5	8.2	3.0	6.5	6.5	7.0	6.0	5.0	6.2	8.0
2	Max dose	37.0	33.0	15.2	23.2	22.5	20.1	15.2	19.8	21.2	16.5	13.0	18.9
	D100%	8.2	7.0	6.8	7.8	6.5	6.0	5.8	7.0	5.8	5.4	5.1	6.0
3	Max dose	33.0	32.0	16.0	17.2	21.7	20.5	15.0	17.8	20.2	19.4	14.2	16.6
	D100%	7.2	7.1	6.8	7.3	5.7	5.3	5.1	6.0	5.2	5.3	5.0	5.8
4	Max dose	32.0	27.0	15.1	17.2	22.2	20.2	14.1	17.8	19.2	18.2	13.2	15.8
	D100%	7.6	7.4	7.0	7.7	6.8	6.6	6.3	6.8	5.9	5.7	5.3	5.7
5	Max dose	28.2	24.0	13.0	15.3	21.7	19.2	13.4	16.7	18.5	18.2	14.2	16.9
	D100%	8.3	8.5	8.2	8.4	7.8	7.7	7.3	7.6	6.7	6.4	6.2	7.0
6	Max dose	26.2	23.0	12.4	15.7	20.4	19.0	15.2	17.2	17.6	18.1	14.0	16.4
	D100%	9.0	8.5	8.2	8.0	8.8	8.2	7.8	7.9	7.2	7.0	6.8	6.9
7	Max dose	24.5	22.6	16	17.2	19.2	17.2	14.5	17.2	17.8	16.2	13.6	16.5
	D100%	8.9	8.7	8.3	8.4	7.8	7.6	7.2	7.7	6.2	6.1	6.0	6.3
8	Max dose	23.5	20.2	14.4	16.2	18.7	17.5	12.6	16.7	17.2	16.8	12.8	14.5
	D100%	8.1	7.9	8.0	8.1	7.8	7.4	7.1	7.3	6.5	6.3	6.0	6.4
9	Max dose	25.0	22.4	15.1	16.8	19.4	18.2	13.4	17.2	18.4	17.3	13.5	15.2
	D100%	7.7	7.6	7.2	7.4	7.2	7.1	7.3	7.4	6.4	6.3	6.3	6.5
10	Max dose	21.0	21.1	14.2	15.9	16.4	15.4	13.1	16.8	17.4	16.8	13.1	14.9
	D100%	8.9	8.7	8.4	8.3	7.5	7.3	7.2	7.3	7.2	7.1	6.9	7.0
AVG	Max dose	28.4	25.5	14.8	18.1	20.4	18.6	14.1	17.6	18.7	17.3	13.3	16.3
	D100%	8.1	7.9	7.6	7.9	6.8	6.9	6.7	7.2	6.3	6.1	5.9	6.5

AVG: average.

Table 5.

The NTCP value of normal organs in three different radiation therapies.

NPCP (%)	3D-CRT				Linac-IMRT				Tomotherapy
NPCP (%)	0 ^o	15 ^o	30 ^o	40 ^o	0 ^o	15 ^o	30 ^o	40 ^o	0 ^o	15 ^o	30 ^o	40 ^o
Hippocampus (%)	3.30	3.00	1.70	2.14	2.40	2.19	1.66	2.07	2.20	2.04	1.57	1.92
Brain stem (%)	0.50	0.60	0.40	0.64	0.42	0.43	0.35	0.58	0.46	0.41	0.39	0.44
Lt lens (%)	1.18	1.00	0.50	0.80	0.56	0.47	0.31	0.43	0.41	0.30	0.31	0.40
Rt lens (%)	0.80	1.10	0.65	0.97	0.66	0.53	0.43	0.84	0.37	0.31	0.22	0.27
Lt Orbit (%)	0.43	0.34	0.29	0.35	0.21	0.18	0.13	0.19	0.19	0.17	0.15	0.16
Rt Orbit (%)	0.42	0.33	0.21	0.35	0.22	0.19	0.10	0.16	0.20	0.19	0.14	0.16

TOOLS

Similar articles