After all the simulation, planning and checking, treatment delivery is where it all comes together.

BeamSite gives clinical teams the power to see what’s happening during the most important time.

  • See real-time video of the beam directly on the patient
  • See entry and exit beams
  • Always on
  • Simple, easy to use
  • No data entry or mouse clicks
  • Record and playback capabilities
  • Improve treatment safety by providing visual feedback
  • Monitor every patient, every day, every fraction
  • Replay any anomalies observed
  • Instill confidence in your patients knowing you have eyes on them, and the beam, at all times.
  • In vivo monitoring of external beam radiation therapy, including photons. Not FDA cleared for electron, protons or brachytherapy.

  • Applicable for 3-D CRT, IMRT, VMAT, SRS, IGRT

  • Monitor stray radiation in out-of-field regions during treatment

  • Confirm patient compliance during treatment

  • Track patients with unusual habitus

  • Identify, track and document errors and near misses


How does it work?

When tissue is irradiated with high energy photons (or electrons) it will glow with visible light, known as Cherenkov.  Although extremely dim, this light can been seen by BeamSite which has been designed specifically to image Cherenkov in radiotherapy treatment rooms.

Can I leave the room lights on?

Yes. BeamSite works by imaging synchronously with the linear accelerator thereby minimizing the impact of room light.

Is it safe?

Yes. No extra radiation is given to the patients to get these images. The images are “free” information produced as a result of the treatment.

What if my patient is covered with clothing or a sheet?

BeamSite relies on line of site of the tissue it is imaging.  Sheets and clothing over the tissue being treated may block some of the light coming from the patient.


The majority of reported radiation incidents are identified during treatment delivery. Record and playback features let therapists share observations with the clinical team. 

Therapists and Physicists are the discoverers of events.

“…many of the errors caught at the time of treatment were identified by alert therapists and other staff before they impacted the patient.”

RO-ILS report Q1 2017.


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  • Glaser, AK, Zhang, R, Gladstone, DJ, Pogue, BW. Optical dosimetry of radiotherapy beams using Cherenkov radiation: the relationship between light emission and dose. Phys Med Biol. 2014;59 (14):3789-811. doi: 10.1088/0031-9155/59/14/3789.

  • Alexander, DA, Tendler, II, Bruza, P, Cao, X, Schaner, PE, Marshall, BS et al.. Assessment of imaging Cherenkov and scintillation signals in head and neck radiotherapy. Phys Med Biol. 2019; doi: 10.1088/1361-6560/ab25a3.

  • Tendler, II, Bruza, P, Jermyn, M, Cao, X, Williams, BB, Jarvis, LA et al.. Characterization of a non-contact imaging scintillator-based dosimetry system for total skin electron therapy. Phys Med Biol. 2019;64 (12):125025. doi: 10.1088/1361-6560/ab1d8a.

  • Bruza, P, Gollub, SL, Andreozzi, JM, Tendler, II, Williams, BB, Jarvis, LA et al.. Time-gated scintillator imaging for real-time optical surface dosimetry in total skin electron therapy. Phys Med Biol. 2018;63 (9):095009. doi: 10.1088/1361-6560/aaba19.

  • Miao, T, Bruza, P, Pogue, BW, Jermyn, M, Krishnaswamy, V, Ware, W et al.. Cherenkov imaging for linac beam shape analysis as a remote electronic quality assessment verification tool. Med Phys. 2019;46 (2):811-821. doi: 10.1002/mp.13303.

  • Andreozzi, JM, Mooney, KE, Brůža, P, Curcuru, A, Gladstone, DJ, Pogue, BW et al.. Remote Cherenkov imaging-based quality assurance of a magnetic resonance image-guided radiotherapy system. Med Phys. 2018;45 (6):2647-2659. doi: 10.1002/mp.12919.

  • Andreozzi, JM, Zhang, R, Gladstone, DJ, Williams, BB, Glaser, AK, Pogue, BW et al.. Cherenkov imaging method for rapid optimization of clinical treatment geometry in total skin electron beam therapy. Med Phys. 2016;43 (2):993-1002. doi: 10.1118/1.4939880.