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SGRT for Clearance Mapping

Recent studies show that non-coplanar treatments can deliver clinically relevant improvements to treatment plans1, specifically in lung cancer 2,3,4,5, breast cancer 6,7,8,9, head and neck cancer 10,11,12,13,14,15 , lymphoma 16,17, and high-grade glioma18 . Traditionally, non-coplanar treatments require extra planning and machine time, both for dry runs and treatments. Additionally, some noncoplanar plans are not deliverable, which can lead to complicated re-planning and repeat quality assurance work, leading to delays in patient treatment and increased costs.

MapRT is intended to make non-coplanar treatments fast, easy and safe. It uses SGRT to deliver a “clearance map”, which planners use to check which beams are deliverable during plan creation.

MapRT images the entire surface of the patient and accessories to detect collisions in the most frequent problem areas such as elbows. In addition, the clearance map checks safety for all couch and gantry angles, so planners have guidance to increase couch kicks and lengthen arcs – for better plans with confidence in delivery. 

How MapRT works:

MapRT uses two lateral wide-field cameras in simulation to deliver a full 3D model of patients and accessories. This model is then used to calculate a clearance map for every couch (x-axis) and gantry (y-axis) angles. Plans can then be imported automatically to check beams, arcs, and the transition clearance.

MapRT can automatically receive and process DICOM RT plans from Eclipse®, Monaco®, Pinnacle®, and RayStation®.

“We see significant value in three areas: checking patient position at CT to ensure a robust setup and avoid unnecessary dose from scans in an unusable position; enhancing planning through increasing the range of beam options; improving the use of resources and the patient experience by avoiding dry runs and delays due to last minute replans.”

Helen Convery
Senior Dosimetrist (Development & Clinical Trials)

Improved assessment of deliverability

A five-center planning study 19 recently showed improved assessment of deliverability using MapRT:

Non-Deliverable Fields
Research shows:

Non-coplanar treatment planning using clearance mapping has shown the potential to enhance outcomes, as shown in this planning study¹² of head and neck retreatments:

Calculated Outcome Probabilities Versus Coplanar VMAT

Would you like to find out more about MapRT?

At Vision RT, we pride ourselves on our responsiveness and customer service.

Whether you’re looking for a quote, a demo (virtual or in-person) or just more information, please get in touch about MapRT or any of our other suite of products: 

1. Smyth G, Evans PM, Bamber JC, Bedford JL. Recent developments in non-coplanar radiotherapy. Br J Radiol. 2019 May;92(1097):20180908. doi: 10.1259/bjr.20180908. Epub 2019 Feb 1. PMID: 30694086; PMCID: PMC6580906.

2. Ma M, Ren W, Li M, Niu C, Dai J. Dosimetric comparison of coplanar and noncoplanar beam arrangements for radiotherapy of patients with lung cancer: A meta-analysis. J Appl Clin Med Phys. 2021 Apr;22(4):34-43. doi: 10.1002/acm2.13197. Epub 2021 Feb 26. PMID: 33634946; PMCID: PMC8035566.

3. Kim ST, An HJ, Kim JI, Yoo JR, Kim HJ, Park JM. Non-coplanar VMAT plans for lung SABR to reduce dose to the heart: a planning study. Br J Radiol. 2020 Jan;93(1105):20190596. doi: 10.1259/bjr.20190596. Epub 2019 Oct 22. PMID: 31625759; PMCID: PMC6948076..

4. Lincoln JD, MacDonald RL, Syme A, Thomas CG. Static couch non-coplanar arc selection optimization for lung SBRT treatment planning. Phys Med Biol. 2023 Jul 21;68(15). doi: 10.1088/1361-6560/ace23f. PMID: 37369237.

5. Chapet O, Khodri M, Jalade P, N’guyen D, Flandin I, D’hombres A, Romestaing P, Mornex F. Potential benefits of using non coplanar field and intensity modulated radiation therapy to preserve the heart in irradiation of lung tumors in the middle and lower lobes. Radiother Oncol. 2006 Sep;80(3):333-40. doi: 10.1016/j.radonc.2006.07.009. Epub 2006 Aug 24. PMID: 16934354.

6. J, F., et al. (2023). Locoregional breast radiotherapy including IMN: optimizing the dose distribution using an automated non-coplanar VMAT-technique. Acta oncologica (Stockholm, Sweden), [online] 62(10). doi:

7. Xu, Y., Ma, P., Hu, Z., Tian, Y., Men, K., Wang, S., Xu, Y. and Dai, J. (2021). Non-coplanar volumetric modulated arc therapy for locoregional radiotherapy of left-sided breast cancer including internal mammary nodes. Radiology and Oncology, 55(4), pp.499–507. doi:

8.  Xu Y, Ma P, Hu Z, Tian Y, Men K, Wang S, Xu Y, Dai J. Non-coplanar volumetric modulated arc therapy for locoregional radiotherapy of left-sided breast cancer including internal mammary nodes. Radiol Oncol. 2021 Nov 19;55(4):499-507. doi: 10.2478/raon-2021-0045. PMID: 34821135; PMCID: PMC8647793.

9. A, B., et al. (2023). Dosimetric Comparision of Coplanar versus Noncoplanar Volumetric Modulated Arc Therapy for Treatment of Bilateral Breast Cancers. Journal of medical physics, [online] 48(3). doi:

10. Biau J, Lopez L, Thivat E, Casile M, Millardet C, Saroul N, Pham-Dang N, Molnar I, Bourhis J, Lapeyre M. Postoperative SBRT in the treatment of early-stage oropharyngeal and oral cavity cancers with high-risk margins: A dosimetric comparison of volumetric modulated arc therapy with or without non-coplanar arcs and acute toxicity outcomes from the STEREOPOSTOP GORTEC 2017-03 phase 2 trial. Clin Transl Radiat Oncol. 2022 Nov 14;38:169-174. doi: 10.1016/j.ctro.2022.11.007. PMID: 36466746; PMCID: PMC9712819.

11. Woods KE, Ma TM, Cook KA, Morris ED, Gao Y, Sheng K, Kishan AU, Hegde JV, Felix C, Basehart V, Narahara K, Shen Z, Tenn S, Steinberg ML, Chin RK, Cao M. A Prospective Phase II Study of Automated Non-Coplanar VMAT for Recurrent Head and Neck Cancer: Initial Report of Feasibility, Safety, and Patient-Reported Outcomes. Cancers (Basel). 2022 Feb 14;14(4):939. doi: 10.3390/cancers14040939. PMID: 35205686; PMCID: PMC8870161.

12. Rwigema JC, Nguyen D, Heron DE, Chen AM, Lee P, Wang PC, Vargo JA, Low DA, Huq MS, Tenn S, Steinberg ML, Kupelian P, Sheng K. 4π noncoplanar stereotactic body radiation therapy for head-and-neck cancer: potential to improve tumor control and late toxicity. Int J Radiat Oncol Biol Phys. 2015 Feb 1;91(2):401-9. doi: 10.1016/j.ijrobp.2014.09.043. Epub 2014 Dec 5. PMID: 25482301.

13.  Gayen S, Kombathula SH, Manna S, Varshney S, Pareek P. Dosimetric comparison of coplanar and non-coplanar volumetric-modulated arc therapy in head and neck cancer treated with radiotherapy. Radiat Oncol J. 2020 Jun;38(2):138-147. doi: 10.3857/roj.2020.00143. Epub 2020 May 26. PMID: 33012157; PMCID: PMC7533406.

14.  Subramanian VS, Subramani V, Chilukuri S, Kathirvel M, Arun G, Swamy ST, Subramanian K, Fogliata A, Cozzi L. Multi-isocentric 4π volumetric-modulated arc therapy approach for head and neck cancer. J Appl Clin Med Phys. 2017 Sep;18(5):293-300. doi: 10.1002/acm2.12164. Epub 2017 Aug 20. PMID: 28834021; PMCID: PMC5874945.

15. Wild, E., Bangert, M., Nill, S. and Oelfke, U. (2015). Noncoplanar VMAT for nasopharyngeal tumors: Plan quality versus treatment time. Medical Physics, 42(5), pp.2157–2168. doi:

16. Rossi L, Cambraia Lopes P, Marques Leitão J, Janus C, van de Pol M, Breedveld S, Penninkhof J, Heijmen BJM. On the Importance of Individualized, Non-Coplanar Beam Configurations in Mediastinal Lymphoma Radiotherapy, Optimized With Automated Planning. Front Oncol. 2021 Apr 15;11:619929. doi: 10.3389/fonc.2021.619929. PMID: 33937025; PMCID: PMC8082440.

17. Chen X, Jin D, Wang S, Li M, Huang P, Dai J. Noncoplanar intensity-modulated radiation therapy for young female patients with mediastinal lymphoma. J Appl Clin Med Phys. 2012 Nov 8;13(6):3769. doi: 10.1120/jacmp.v13i6.3769. PMID: 23149772; PMCID: PMC5718536.

18. Yu VY, Landers A, Woods K, Nguyen D, Cao M, Du D, Chin RK, Sheng K, Kaprealian TB. A Prospective 4π Radiation Therapy Clinical Study in Recurrent High-Grade Glioma Patients. Int J Radiat Oncol Biol Phys. 2018 May 1;101(1):144-151. doi: 10.1016/j.ijrobp.2018.01.048. Epub 2018 Jan 31. PMID: 29619962.

19. Ke Sheng presentation SGRT Community Meeting 2022, “Surface Guided Clearance Mapping: See More, Do More and Achieve More”

MapRT is protected under various granted and pending patents including US Issued Patent 10,549,116 (Filed January 3rd, 2016)