Skip to main content
Learn More About Proton Therapy
Learn More About Proton Therapy

Healthcare Providers

Below are resource materials most relevent to healthcare providers

Health Care Provider FAQs about the MEVION S250 Series


1. What energy is your synchrocyclotron?

The MEVION S250 Series TriNiobium Superconducting Cyclotron has a maximum energy of 250MeV.

2. What is the background dose to patients

The MEVION S250 and S250i accelerator and Direct Dose™ beam line design assures that background dose to patients including neutrons is similar to other proton therapy systems and well below the IEC limit for radiotherapy of 1 mSv/Gy.

The MEVION S250 neutron dose to a patient is one-tenth the background dose experienced from a high energy Linac.

The MEVION S250i further reduces the neutron dose by a one fourth due to its scanned beam design.

3. Are magnetic fields a concern for the MEVION S250?

No, the residual field with in the treatment room is less than 10 Gauss.

4. What is the noise level in the treatment room? 

The noise level in the MEVION S250 treatment room is similar to the noise in any conventional radiation therapy room.

5. Has the MEVION S250 been cleared by the USFDA?

Yes, the MEVION S250 is has USFDA Clearance. It also has Health Canada clearance.

6. Does the MEVION S250 comply with MDD/CE requirements?

Yes, the MEVION S250 complies with the MDD/CE requirements.

Service, Maintenance and Training

1. What is the average cost and length of a service agreement?

One year of service and maintenance is included in the price of the system. Additional coverage is optional with cost dependent on the services and term selected.

2. What is the anticipated service presence?

When necessary, Mevion provides an on site engineer who will work at the customer facility and provide support services to our customers to guarantee a more than 95% clinical uptime.

3. How often does the system require routine maintenance?

Routine maintenance is performed on a quarterly basis and Mevion provides a preventative maintenance schedule listing the items to be serviced and the required down times. Scheduled maintenance is typically performed on weekends, outside of working hours and lasts from 1 to 3 days.

4. How long before personnel can access the accelerator for service?

Access to the Mevion accelerator is possible within minutes of turning the beam off. With its efficient MEVION S250 proton source and direct beam architecture, the accelerator only requires a few nano-amps of beam current to deliver 2Gy/min/liter. This greatly decreases the level of radioactivity created in Mevion equipment compared to current accelerators previously used for proton therapy.

5. What is the guaranteed uptime?

Mevion contractually guarantees an uptime and availability of 95%, and our customers are routinely experiencing more than 98% uptime.

6. What types of educational and training programs are offered?

Clinical: Mevion provides a very comprehensive training program for physicians, therapists, dosimetrists and physicists. Training is principally conducted onsite with courses lasting from 2 to 4 days at no additional cost.

Facility: Engineering support training is provided to engineers at the site.

Off-site: An extensive program of visiting programs is available at other Mevion sites.

7. Is there 24/7 support?

Yes, Mevion provides on-site support available for all clinical hours and has a response team available 24/7 for any urgent matters.

8. What is the average response time for a service issue?

The average response time is 5-10 minutes.


1. Does the MEVION S250 integrate with other clinical system and programs?

Mevion integrates with leading Oncology partners delivering a clinical workflow that is optimized for Image-Guided, Volumetric, and Intensity Modulated Proton Therapy treatment delivery. The workflow is easy to use and similar to advanced linear accelerator systems providing an easy transition for any radiation oncology department.

2. What 3rd party vendors are supported?

Treatment Planning: RaySearch RayStation™, Philips Pinnacle™, Varian Eclipse™, Elekta XiO™

OIS: RaySearch RayCare™, Varian ARIA™, Elekta MOSAIQ™

Motion Management Systems: VisionRT AlignRT® and GateRT®, humediQ Identify, C-RAD Catalyst

CT Imaging: Airo®, BodyTom®, Siemens CTVision™

Immobilization: Qfix kVue™, BoS™ Insert, BoS™ Headframe

3. Do you offer or require a proprietary treatment planning system?

No, Mevion is designed to integrate with leading radiation therapy treatment planning and oncology information systems. Some proprietary features of HYPERSCAN with Adaptive Aperture are only available on the RaySearch RayStation treatment planning system.

4. What types of treatment techniques are supported?

Image-Guided, Intensity Modulated Proton Therapy, Pencil Beam Scanning and Double Scattering are supported. Mevion proprietary HYPERSCAN with Adaptive Aperture provides precision collimation in IMRT for all treatment depths.

5. What is the minimum and maximum range that can be treated?

The MEVION S250 can treat from 5 - 32 g/ cm2 without a range compensator. The MEVION S250i can treat from the 0 g / cm2 to 32 g/cm2

6. How does the MEVION S250 Series differ from traditional proton therapy systems?

Unlike existing proton centers and other compact systems in the market, the MEVION S250 Series is the only true single room proton therapy system and the smallest system on the market, with a proton accelerator designed (not adapted) for proton therapy. Capital costs and ongoing power expenses are each the lowest on the market. Minimum financial outlay and project risks make proton therapy with the MEVION S250 Series available to a wider range of hospitals and patients than traditional systems.

7. How many patients can be treated per day?

Mevion centers have demonstrated treating over 40 patients per day on a regular basis. All normal maintenance can be scheduled during weekend hours to not impact treatment and physics schedules.

8. How many staff members do you need to run the system?

Only a standard radiation therapy staff is needed to run a MEVION S250 Proton Therapy System. There are no accelerator operators and on-site service is not required.

9. How many hours is the beam available for treatment?

The MEVION S250 Series is clinically available 24 hours a day without down time, so treatment can be delivered at any time.

10. What is the average time to get to first clinical patient treatment?

The Mevion centers have started clinical treatment following 4 to 9 weeks of clinical commissioning. They have also very rapidly started treated pediatric patients.

11. What is the time to complete acceptance testing?

Acceptance testing is completed in 7 days.

12. What is the average time of treatment?

Typical treatment times are 10 to 15 minutes for a two-fields intracranial or prostate treatment and 20 minutes for more complex liver and lung treatments. Treatment times for pediatric patients with anesthesia will vary from 35 to 45 minutes.

Construction and Financial Costs

1. Can I add a system to an existing department?

Yes. Due to the small size and the unique single room configuration of a MEVION S250 Series bunker, many of our customers have been able to add a system to an existing building or transform a previous facility into a proton therapy center.

2. Do you provide project management services?

Yes, project management services are provided in the construction and installation phases.

3. How much space is needed?

The internal footprint of a MEVION S250 Series room is 32ft x 37ft (9.8m x 11.3m). The required height of the entire bunker is 28ft (8.43m)

4. How long is the installation process?

Mevion’s installation process requires 10 months from building construction to acceptance testing.

5. Do you offer commissioning services?

No, Mevion does not offer commissioning services.

We do provide physics education and can refer to a network of independent physicists to assist with commissioning.

6. What is the average electrical cost?

The MEVION S250 electrical requirements are similar to a conventional radiation therapy machine, needing only 94KVA for Beam On and 57KVA for Standby. This translates into cost that is only a 10th of what other proton systems generate and is ~$60k per year.

7. What type of financial services offered?

Mevion offers customized business and financing programs that vary depending on individual needs.

8. What other services are offered?

Mevion’s Customer Care Continuum offers a variety of services that can be tailored to fit your individual needs such as:

Global Implementation Services

Global Customer Care Services

Global Collaboration Services

9. What is the average ROI?

Many of Mevion’s customers have met or exceeded 100% of their initial business plans in the first year with a scheduled ROI in just 5 years.

Success Stories

About Mevion

Learn More

MEVION S250™ Treatment Locations

Learn More