Practical implementation of Enhanced Dynamic Wedge in the CadPlan treatment planning system

Samuelsson, Anna; Johansson, Karl-Axel; Mattsson, O.; Palm, Åsa; Puurunen, H.; Sernbo, Göran

doi:10.1016/s0958-3947(97)00019-8

Cited by 10 publications

(5 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the past several years, a series of investigations have been reported on the implementation and dosimetric characterization of EDW for various treatment planning systems, such as Pinnacle (Shao et al 2004, Alaei et al 2005, FOCUS (Miften et al 2000, Klein et al 1998, Klein 1997, CadPlan (Samuelsson et al 1997, Koken et al 2003, Helax (Karlsson 1997) and Theraplan (Cramb and Ackerly 1997). Some other studies have been focused on the enhanced dynamic wedge factor calculations (Sethi et al 2000, Liu et al 1998, Kuperman 2004, 2005, Gibbons 1998) and quality assurance of EDW (Moeller et al 1997, Greer and Barnes 2007, Alaei and Higgins 2006.…”

Section: Introductionmentioning

confidence: 99%

Clinical implementation of enhanced dynamic wedges into the Pinnacle treatment planning system: Monte Carlo validation and patient-specific QA

Ahmad¹,

Deng²,

Lund³

et al. 2008

Phys. Med. Biol.

View full text Add to dashboard Cite

The goal of this work is to present a systematic Monte Carlo validation study on the clinical implementation of the enhanced dynamic wedges (EDWs) into the Pinnacle(3) (Philips Medical Systems, Fitchburg, WI) treatment planning system (TPS) and QA procedures for patient plan verification treated with EDWs. Modeling of EDW beams in the Pinnacle(3) TPS, which employs a collapsed-cone convolution superposition (CCCS) dose model, was based on a combination of measured open-beam data and the 'Golden Segmented Treatment Table' (GSTT) provided by Varian for each photon beam energy. To validate EDW models, dose profiles of 6 and 10 MV photon beams from a Clinac 2100 C/D were measured in virtual water at depths from near-surface to 30 cm for a wide range of field sizes and wedge angles using the Profiler 2 (Sun Nuclear Corporation, Melbourne, FL) diode array system. The EDW output factors (EDWOFs) for square fields from 4 to 20 cm wide were measured in virtual water using a small-volume Farmer-type ionization chamber placed at a depth of 10 cm on the central axis. Furthermore, the 6 and 10 MV photon beams emerging from the treatment head of Clinac 2100 C/D were fully modeled and the central-axis depth doses, the off-axis dose profiles and the output factors in water for open and dynamically wedged fields were calculated using the Monte Carlo (MC) package EGS4. Our results have shown that (1) both the central-axis depth doses and the off-axis dose profiles of various EDWs computed with the CCCS dose model and MC simulations showed good agreement with the measurements to within 2%/2 mm; (2) measured EDWOFs used for monitor-unit calculation in Pinnacle(3) TPS agreed well with the CCCS and MC predictions within 2%; (3) all the EDW fields satisfied our validation criteria of 1% relative dose difference and 2 mm distance-to-agreement (DTA) with 99-100% passing rate in routine patient treatment plan verification using MapCheck 2D diode array.

show abstract

Section: Introductionmentioning

confidence: 99%

Clinical implementation of enhanced dynamic wedges into the Pinnacle treatment planning system: Monte Carlo validation and patient-specific QA

Ahmad¹,

Deng²,

Lund³

et al. 2008

Phys. Med. Biol.

View full text Add to dashboard Cite

show abstract

“…The relationship between jaw position and the percentage of total monitor units delivered is described in a segmented treatment table. The segmented treatment table is used to generate the primary intensity function matrix used by the pencil‐beam convolution (PBC) (7) …”

Section: Introductionmentioning

confidence: 99%

“…Several works that compare measured and calculated dose in the field axis using DW, such as Papatheodorou et al 1998, (3) Bayouth and Steinberg 1997, (5) and Samuelsson et al 1997 (7) , conclude that the TPS accurately models the wedged dose distributions for symmetric fields, with dose variations below 2% of the normalization or 2 mm for regions with high dose gradient. However, no reports using DW compare measured with calculated two‐dimensional (2D) dose distributions.…”

Section: Introductionmentioning

confidence: 99%

Comparison between measured and calculated dynamic wedge dose distributions using the anisotropic analytic algorithm and pencil‐beam convolution

Caprile

Venencia

Besa

2007

J Applied Clin Med Phys

View full text Add to dashboard Cite

We used the two available calculation algorithms of the Varian Eclipse 7.3 three‐dimensional (3D) treatment planning system (TPS), the anisotropic analytic algorithm (AAA) and pencil‐beam convolution (PBC), to compare measured and calculated two‐dimensional enhanced dynamic wedge (2D EDW) dose distributions, plus implementation of the dynamic wedge into the TPS. Measurements were carried out for a 6‐MV photon beam produced with a Clinac 2300C/D linear accelerator equipped with EDW, using ionization chambers for beam axis measurements and films for dose distributions. Using both algorithms, the calculations were performed by the TPS for symmetric square fields in a perpendicular configuration. Accuracy of the TPS was evaluated using a gamma index, allowing 3% dose variation and 3 mm distance to agreement (DTA) as the individual acceptance criteria. Beam axis wedge factors and percentage depth dose calculation were within 1% deviation between calculated and measured values. In the non‐wedged direction, profiles exhibit variations lower than 2% of dose or 2 mm DTA. In the wedge direction, both algorithms reproduced the measured profiles within the acceptance criteria up to 30 degrees EDW. With larger wedge angles, the difference increased to 3%. The gamma distribution showed that, for field sizes of 10×10 cm or larger, using an EDW of 45 or 60 degrees, the field corners and the high‐dose region of the distribution are not well modeled by PBC. For a 20×20 cm field, using a 60‐degree EDW and PBC for calculation, the percentage of pixels that do not reach the acceptance criteria is 28.5%; but, using the AAA for the same conditions, this percentage is only 0.48% of the total distribution. Therefore, PBC is not reliable for planning a treatment when using a 60‐degree EDW for large field sizes. In all the cases, AAA models wedged dose distributions more accurately than PBC did.PACS numbers: 87.53.Bn, 87.53.Dq, 87.53.Kn

show abstract

“…The EDW has been studied by many authors. [5][6][7][8][9][10][11][12][13][14][15][16] It presents many advantages over the physical wedge. However, in order to calculate MUs necessary to deliver a certain dose at a certain point, EDW factors need to be determined.…”

Section: Introductionmentioning

confidence: 99%

Analytical representation of enhanced dynamic wedge factors for symmetric and asymmetric photon fields

2002

Medical Physics

View full text Add to dashboard Cite

The Enhanced Dynamic Wedge (EDW) presents many advantages over the physical wedge. However, in order to calculate monitor units (MUs) necessary to deliver a certain dose at a certain point, EDW factors (EDWFs) need to be determined. In this work, based on analysis of the golden segmented treatment table (GSTT) and the MU fraction model, an empirical analytic formula has been developed to calculate EDW factors for symmetric and asymmetric fields. This formalism is an extension of the MU fraction model. However in comparison with previous studies [J. P. Gibbons, Med. Phys. 25, 1411-1418 (1998) and M. Miften et al., Med. Dosim. 25, 81-86 (2000)], this formula is simpler, and easier to use. It is applicable to EDW fields of different sizes, wedge angles and different photon energies. For 6 and 18 MV beams from a Varian 21EX accelerator with 7 EDW angles (Varian Oncology Systems, Palo Alto, CA), more than 250 measured EDWFs for symmetric and asymmetric fields with different off-axis distances and field sizes were compared with model calculations. Results show that 80% and 98% of calculated EDWFs match corresponding measured values to within 0.5% and 1.0%, respectively, the maximum deviation being 1.3%.

show abstract

Practical implementation of Enhanced Dynamic Wedge in the CadPlan treatment planning system

Cited by 10 publications

References 4 publications

Clinical implementation of enhanced dynamic wedges into the Pinnacle treatment planning system: Monte Carlo validation and patient-specific QA

Clinical implementation of enhanced dynamic wedges into the Pinnacle treatment planning system: Monte Carlo validation and patient-specific QA

Comparison between measured and calculated dynamic wedge dose distributions using the anisotropic analytic algorithm and pencil‐beam convolution

Analytical representation of enhanced dynamic wedge factors for symmetric and asymmetric photon fields

Contact Info

Product

Resources

About