Dosimetric Comparison: Acuros XB vs AAA

Epworth HealthCare

Excellence. Everywhere. Everyday

Dosimetric Comparison:

Acuros XB vs AAA Leo El Hage, Chris James, Jim Frantzis, Roger Li, Venkata Sheshadri

Epworth Radiation Oncology

Background

2

• Epworth Radiation Oncology

• Eclipse™ Treatment Planning System (TPS) v10

- Anisotropic Analytical Algorithm (AAA)

- ACUROS XB

- Pencil Beam Algorithm

• Epworth Radiation Oncology was one of the first

sites in Australia to commission Acuros

• Currently: AAA for calculations using Megavoltage

(MV) photons

Background

3

• Acuros : Accurate and Fast

• Boltzmann Transport Equation (BTE)

• In-house evaluation was required

• Literature search

• Clinical impact

• Positives and negatives

Background

4

Eclipse™ Acuros XB • Reported to improve dose

calculation accuracy (Fogliata et al,2011)

• Matched only by Monte Carlo

(Han et al, 2011)

• Better dose prediction than AAA

– Low density lung

– Fat

– Bone

– Air (Bush et al, 2011)

Bush et al 2011

Algorithm Comparison

5

Monte Carlo Gold Standard, but slow..?

Structure Monte Carlo Acuros AAA

Lung = x

Bone = X

Fat = X

Air = X

• Acuros: equivalent to 0.5 %

• AAA : 3.5% to 6.4% ( Han et al, 2011)

Method

6

•CIRS Thorax Phantom

•Point Dose measurements

•Ethics approval from Epworth H.R.E.C.

•Clinical Data sets

•Time Study

AAA vs ACUROS

Method : CIRS Phantom

7

Method

8

Plan Comparisons – Clinical datasets

• 5 plans selected in 4 different sites:

Pelvis – Breast – Thorax - Head & Neck

• Calculation algorithm changed to Acuros and re-calculated (total 40

plans)

• Same Monitor Units and 2.5mm Grid size

• Plans compared via

– DVH analysis

– Conformity Index

• Calculation time comparison

Method

9

Calculation Of Conformity Index (CI)

The CI was measured using the following formula

= total volume of the PTV

= total volume of 95% isodose line and is

= the volume of their intersection

DD

DD

VV

VVCI

43

432

DV3

DV4

DD VV 43

CI Closer to 0 CI Closer to 1.0

Van’t Riet, et al. 1997

10

Results Phantom Point Dose Measurements

11

Results

7 10

Phantom Point Dose Measurements

6

Results

12

Calculation Times

13

Results Breast Plan Comparison

Plan 1 2 3 4 5

AAA ACUROS AAA ACUROS AAA ACUROS AAA ACUROS AAA ACUROS

Mean Dose 50.52 Gy 50.57 Gy 50.47 Gy 50.30Gy 50.29 Gy 50.27 Gy 49.56 Gy 48.94 Gy 49.77 Gy 49.31 Gy

D 95 % 48.13 Gy 47.97 Gy 47.80 Gy 46.72Gy 47.80 Gy 47.65 Gy 45.46 Gy 43.28 Gy 46.26 Gy 46.11 Gy

D 98 % 47.86 Gy 47.45 Gy 45.51 Gy 44.782Gy 47.50 Gy 47.06Gy 43.64 Gy 41.08 Gy 45.00 Gy 45.10 Gy

D 2% 52.50 Gy 52.91 Gy 52.88 Gy 53.14Gy 52.22G y 52.48 Gy 52.82 Gy 52.86 Gy 53.44 Gy 52.90 Gy

CI 0.63 0.57 0.88 0.86 1.0 0.96 0.93 0.93 0.93 0.91

14

Results Breast Plan Comparison

Plan 1 2 3 4 5


Mean Dose 50.52 Gy 50.40 Gy 50.29 Gy 49.56 Gy 49.77 Gy

D 95 % 48.13 Gy 47.80 Gy 47.80 Gy 45.46 Gy 46.26 Gy

D 98 % 47.86 Gy 45.51 Gy 47.50 Gy 43.64 Gy 45.00 Gy

D 2% 52.50 Gy 52.88 Gy 52.22G y 52.82 Gy 53.44 Gy

CI 0.63 0.88 1.0 0.93 0.93

15

Results Pelvis Plan Comparison

Plan 1 2 3 4 5



D 95 % 54.30 Gy 76.35 Gy 75.20 Gy 53.36 Gy 67.61 Gy

D 98 % 53.25 Gy 75.78 Gy 74.50 Gy 53.08 Gy 66.22 Gy

D 2% 60.30 Gy 79.36 Gy 77.59 Gy 55.36 Gy 73.40 Gy

CI 0.83 0.89 0.87 0.90 0.90

16

Results Thorax Plan Comparison

Plan 1 2 3 4 5



D 95 % 48.03 Gy 37.13 Gy 39.42 Gy 38.73 Gy 48.60 Gy

D 98 % 47.69 Gy 36.29 Gy 38.79 Gy 38.20 Gy 48.00 Gy

D 2% 52.90 Gy 41.72 Gy 43.33 Gy 41.15 Gy 51.0 Gy

CI 0.83 0.67 0.74 0.6 0.82

17

Results Head & Neck Plan Comparison

Plan 1 2 3 4 5


Mean Dose 58.47Gy 52.90Gy 51.51gy 68.74Gy 59.46Gy

D 95 % 52.95Gy 48.66Gy 39.65Gy 65.51Gy 53.91Gy

D 98 % 47.10Gy 46.50Gy 29.38Gy 64.36Gy 50.46Gy

D 2% 62.93Gy 55.17Gy 55.17Gy 71.77Gy 61.99Gy

CI 0.873 0.844 0.495 0.951 0.767

Isodose Evaluation

Discussion

18

AAAAAA ACUROSACUROS

Discussion: Pelvis

19

95% - AAA 95% - AAA

95% - ACUROS 95% - ACUROS

95% - AAA 95% - AAA

Discussion: Thorax 3DCRT

20

95% - ACUROS 95% - ACUROS

95% - AAA 95% - AAA

Discussion: Head & Neck

21

Conclusion

22

• Phantom study – Acuros = measured

• Acuros is a better predictor of dose than AAA

• Can over or under estimate dose to PTV and

conformity of 95% isodose

• More dose phantom measurements required for

Acuros

• Not ready to implement

ACKNOWLEDGMENTS

23

• Special Mention to:

• Jim Frantzis

• Andrew Do

• Louis Huynh

• Yolanda Aarons

• Yen Tran

• Hannah Bignell

• Priya Gautam

• All the ERO team for their commitment to their professionalism and

support

REFERENCES

24

• Bueno, M., Duch, M.A., Jurado Bruggeman, D., Agramunt Chaler, S., Munoz C., Dosimetric Verification of Acuros XB in

Heterogeneities Against Experimental Measurements and monte Carlo Methods, ESTRO 31

• Bush, K., Ansbacher, W., Wang, L., Mok, E., Xing, L., Fast and Accurate Solution of the Boltzmann Radiation Transport

Equation for RT: Implementation and Validation., Stanford University, Radiation Oncology, Stanford CA, USABritish

Columbia Cancer Agency - Vancouver Island Centre, Medical Physics, Victoria BC, Canada

• Bush, K., Gagne, I.M., Zavorodni, S., Ansbacher, W., Beckham, W., Dosimetric validation of Acuros® XB with Monte Carlo

methods for photon dose calculations, Department of Medical Physics, British Columbia Cancer Agency–Vancouver Island

Center, Victoria,British Columbia V8R 6V5, Canada, 2011

• Failla, G et al. Acuros ®XB advanced dose calculation for Eclipse™ planning system, Varian Medical Systems, Clinical

Perspectives, Acuros XB.

• Fogliata A., Nicolini, G., Clivio, A., Vanetti, E., Cozzi, L., Advanced Lung Treatment Using Different Modalities: Comparison

of Acuros XB and AAA Dose Calculations, Oncology Institute of Southern Switzerland, Medical Physics, Bellinzona,

Switzerland.

• Fogliata A., Nicolini, G., Clivio, A., Vanetti, E., Cozzi, L., Critical Appraisal of Acuros XB and Anisotropic Analytic Algorithm

Dose Calculation in Advanced Non-Small-Cell Lung Cancer Treatments. Medical Physics Unit, Oncology Institute of

Southern Switzerland, Bellinzona, Switzerland, 2011

• Fogliata A., Nicolini, G., Clivio, A., Vanetti, E., Mancosu, P., Cozzi, L., Dosimetric evaluation of Acuros XB Advanced Dose

Calculation algorithm in heterogeneous media, Radiation Oncology, Vol 6, pp. 82, 2011

• Fogliata A., Nicolini, G., Clivio, A., Vanetti, E., Mancosu, P., Cozzi, L., Dosimetric validation of the Acuros XB Advanced Dose

Calculation algorithm:fundamental characterization in water., Phys. Med. Biol., Issue 56, pp. 1879-1904, 2011

REFERENCES (2)

25

• Fogliata A., Nicolini, G., Clivio, A., Vanetti, E., Mancosu, P., Cozzi, L., Dosimetric validation of the Acuros XB Advanced

Dose Calculation algorithm:fundamental characterization in water., Phys. Med. Biol., Issue 56, pp. 1879-1904, 2011

• Fogliata, A., et al. On the dosimetric impact of inhomogeneity management in the Acuros XB algorithm for breast

treatment, Radiation Oncology 2011, Issue 6, pp. 103

• Han et al., Dosimetric evaluation of AXB in heterogeneities. Med. Phys., Vol 38, Issue 5, 2011

• Int J Radiat Oncol Biol Phys, Vol 37, pp. 731-736, 1997

• Kan, Leung, and Yu: Impact of Acuros XB on IMSRT for NPC, Med. Phys., Vol 39, Issue 8 , 2012

• Knöös, T., Kristensen, I., Per Nillson, Volumetric and Dosimetric Evaluation of Radiation Treatment Plans: Radiation

Conformity Index, Division of Radiation Therapy Physics, Department of Radiation Physics, Lund University Hospital,

Lund, Sweden, Int. J. Radiation Oncology Biol. Phys., Vol. 42, No. 5, pp. 1169–1176, 1998

• Sakthi, N., Keall, P., Mihaylov, I., Wu, Q., Wu, Y., Willamson, J., Schmidt-Ullrich, R., Siebers, J., Monte Carlo-Based

Dosimetry of Head and Neck Patients Treated with SIB-IMRT, Department of Radiation Oncology, Virginia

Commonwealth University, Richmond,VA. Int. J. Radiation Oncology Biol. Phys., Vol. 64,Issue 3, pp. 968–977, 2006

• Tao H., Mikell, J.K., Salehpour, M., Mourtada, F., Dosimetric comparison of Acuros XB deterministic radiation transport

method with Monte Carlo and model-based convolution methods in heterogeneous media.Med. Phys., Vol 38, Issue 5,

2011

• Van’t Riet, A, Mak, AC, Moerland, MA, et al. A conformation number to quantify the degree of conformality in

brachytherapy and external beam irradiation: Application to the prostate.

Documents

Dosimetric Comparison: Acuros XB vs AAA