Mediterranean Institute of Proton Therapy

The Mediterranean Institute of Proton Therapy (IMPT) is the dedicated proton therapy center of the Antoine Lacassagne Cancer Center in Nice, set on the hills above the French Riviera. Patients arrive at a site that feels both clinical and contemporary: a compact high-tech campus where proton therapy, CyberKnife radiosurgery, and conventional radiotherapy sit side by side, so that each case can be matched with the most appropriate, finely tuned radiation technique rather than a one-size-fits-all approach. What makes IMPT distinctive is its dual proton platform. On one side is MEDICYC, a 65 MeV isochronous cyclotron dedicated primarily to ocular tumors since the early 1990s. It was at this facility that France’s first proton therapy treatment for an eye melanoma was performed in 1991. Over the decades, more than 4,500 ocular tumors have been treated there, giving the team one of the longest and largest experiences in eye proton therapy in Europe. Alongside MEDICYC, Proteus®ONE is a compact, high-energy proton system (up to 235 MeV) equipped with a rotating gantry for deep-seated tumors. Installed at Nice as Europe’s first Proteus®ONE site – and among the earliest worldwide - it was commissioned in 2016 and later upgraded with cone-beam CT image guidance, making IMPT the first proton center in France to pair this technology with a Proteus®ONE room. This combination allows millimetric, image-guided treatments for complex tumors of the brain, skull base, spine, and pelvis, as well as selected pediatric cases where tissue sparing is crucial. Because the two proton units are co-located within a large comprehensive cancer center, patients benefit from more than just sophisticated machines. Clinical pathways involve multidisciplinary decision-making, where professionals such as radiation oncologists, neurosurgeons, ophthalmologists, ENT surgeons, medical physicists, dosimetrists, and radiographers collaborate during tumor board meetings. Together, they evaluate cases to determine if proton therapy is appropriate and, if so, whether to use the ocular line or the high-energy gantry for the specific target. For an eye melanoma, this might mean a short course of highly focused treatment on MEDICYC, preserving the eye and often functional vision; for a skull-base chordoma or a pediatric brain tumor, it might mean several weeks of fractionated high-energy proton therapy with meticulous dose sculpting around the brainstem and optic nerves. IMPT’s philosophy is rooted in precision – not just in how beams are shaped, but in how tumor motion is understood and managed. Thanks to a 4D CT scanner and the Sentinel respiratory tracking system, the team can literally “film” tumors that move with breathing, building a time-resolved map of the lesion's location throughout the respiratory cycle. This information feeds into treatment planning so that fields can be gated or margins adapted, allowing proton therapy to be extended beyond static head-and-neck or CNS targets to selected thoracic and upper-abdominal indications, such as certain lung and liver tumors that benefit from the proton dose fall-off. Day to day, care is delivered by dedicated proton therapy teams embedded within the Antoine Lacassagne Cancer Center’s wider infrastructure. Patients have access to on-site imaging (CT, MRI, PET-CT), supportive care services, and, when needed, inpatient hospital departments, but many can remain ambulatory throughout treatment. For those who live far from Nice or abroad, practical support is provided through nearby accommodation options such as the “La Consolata” patient lodge, which offers a hotel-style environment close to the center for individuals who do not require continuous hospital monitoring yet need to stay near the machines for several weeks.