Volumetric Modulated Arc Therapy (VMAT) Lindsay Gerner Jessica Nyquist

Description Rotational 360 degree radiation therapy treatment Photons are used Beam is continually shaped during treatment Shaped to the tumor Specific to each angle Every angle is achievable with arc therapy Targets tumor directly Spares more normal tissue and organs at risk Tomotherapy and Arc Therapy are the only two forms of arc based therapy Tomotherapy requires a specific machine VMAT can be achieved by a conventional linear accelerator

Background Varian: Rapid Arc Therapy Elekta: Volumetric Modulated Arc Therapy Implemented in over 300 locations worldwide Idea described in 1995 Dr. Cedric Yu Referred to as IMAT (Intensity Modulated Arc Therapy) Introduced in 2007 VMAT tested in Europe in 2007 The Royal Marsden Hospital in Suttok, UK General Hospital Vienna in Austria

Cancers Pancreatic Cancer Prostate Lung CNS tumors Pelvic Malignancies Not found until very advanced Works well for sparing normal surrounding tissue Prostate Lung Ex: Mesothelioma CNS tumors Close proximity to many critical structures Ex: Malignant glioma Pelvic Malignancies Ex: Anal, rectal, and gynecologic cancers Head and Neck Beneficial for sparing the many critical structures that surround head and neck tumors Ex: Parotid, esophageal, pharyngeal, and brainstem cancers

Process Treatments are planned by sophisticated computer software Extensive planning takes several days for dosimetrist, doctor, and physicist to plan Tumor contours are perfected Size, shape, and location of tumor is identified Therapists roles do not change significantly when utilizing arc therapy Patient positioning Patient marking (tattooing)

Treatment Administered 5 times weekly for two to three weeks Radiation remains active while gantry is rotating around patient 50% faster than IMRT Treatments can be as quick as 2 minutes Complex cases can take up to 5 minutes

Cost Radiation Charges Insurance Doctor’s fee Films Treatment Planning Verification films Equipment use & supplies Daily therapy Insurance Coverage is similar to traditional radiation therapy

Results Eligible patients Treatment outcomes Cancers previously mentioned May not be necessary for simple setups or palliative patients Treatment outcomes Improved accuracy Less patient side effects due to normal tissue spared

Advantages and Disadvantages Uninterrupted field delivery Linear Accelerator is used 40cm X 40cm maximum field size 45cm from source to patient Continuous dose rate 50% faster than IMRT Treatments can be as quick as 2 minutes Complex cases can take up to 5 minutes Reduces dose to organs and normal tissue Non coplanar technique Rotational treatment

Photos Elekta VMAT. Retrieved from http://blog.elekta.com/blog/2010/07/auckland-radiation-oncology-first-clinic-in-new-zealand-to-adopt-elekta-vmat/ Varian Rapid Arc. Retrieved from http://www.osl.uk.com/rte.asp?id=517

References Eppinga, W., Lagerwaard, F.,M.D.PhD., Verbakel, W., Slotman, B., & Senan, S. (2010). Volumetric modulated arc therapy for advanced pancreatic cancer. Strahlentherapie Und Onkologie, 186(7), 382-7. doi:http://dx.doi.org/10.1007/s00066-010-2094-5 Scorsetti, M., Fogliata, A., Castiglioni, S., Bressi, C., Bignardi, M., Navarria, P., . . . Santoro, A. (2010). Early clinical experience with volumetric modulated arc therapy in head and neck cancer patients. Radiation Oncology, 5, 93. doi:http://dx.doi.org/10.1186/1748-717X-5-93 Web, S. (June, 2009). Volumetric-modulated arc therapy: its role in radiation therapy. Medical Physics Web. Retrieved from http://medicalphysicsweb.org/cws/article/opinion/39542 ELEKTA. (2014). Next generation arc therapy for faster treatments, lower radiation dose to the patient. Elekta. Retrieved from http://www.elekta.com/healthcare-professionals/products/elekta-oncology/treatment- techniques/delivery-techniques/elekta- vmat.html?utm_source=vmat&utm_medium=redirect&utm_campaign=redirects Volumetric Modulated Arc Therapy. (June, 2009). Volumetric Modulated Arc Therapy. Swedish Cancer Institute. Retrieved from http://www.swedish.org/services/cancer-institute/services/radiation-therapy/types- of-radiation-therapy/volumetric-modulated-arc-therapy-vmat