The most read article of the year, however, concerned the launch of a new treatment system at the ESTRO 36 meeting in Vienna. Halcyon addresses global radiotherapy gap describes Varian Medical Systems' Halcyon radiotherapy system, a totally new device created to expand worldwide access to high-quality cancer care, while reducing the total cost of ownership for hospitals. The system, which was also designed to simplify clinical operations for users and increase patient comfort, is now in clinical use around the globe.

Into the clinic
Echoing the results of the last few years, the second most read article was about MRI-guided radiotherapy, specifically, the first patient treatment using the Unity MRI-guided radiotherapy system. First patient treated on the Unity MRI-linac describes this high-precision treatment, on a patient with spinal bone metastases, which took place in May at UMC Utrecht.

Next up, Compact linac designed for proton therapy examined a design for a compact, fully linear accelerator for proton therapy, developed by a team at CERN. Reflecting ongoing developments in shrinking the size of the accelerator system, the researchers aim to create a linac-based proton therapy facility that is as compact as possible, ideally with a product that fits into existing hospital buildings.

The big debate
Pulling together the themes of the previous two articles, the next story reported on a lively "protons versus photons" debate, also held at ESTRO 36. The article, Proton-guided photons or photon-guided protons? covered a conference session in which Bas Raaymakers and Tony Lomax deliberated whether MRI-guided photon radiotherapy (proton-guided photons) or cone-beam CT-guided proton therapy (photon-guided protons) will emerge as the superior treatment technique.

The final article on this year's list is An alternative approach to small-field dosimetry. In this study, researchers in Finland demonstrated an alternative approach for dosimetry of small fields - a task that's becoming increasingly important with the rise in popularity of precision techniques such as intensity-modulated radiotherapy, volumetric-modulated arc therapy and stereotactic body radiotherapy. The authors present the dose-area-product ratio, a measure of beam quality that could enable more accurate dose delivery in patients.

The top five articles of 2017
Halcyon addresses global radiotherapy gap
First patient treated on the Unity MRI-linac
Compact linac designed for proton therapy
Proton-guided photons or photon-guided protons?
An alternative approach to small-field dosimetry