Développement de l'appareil Papillon 50 TM et de ses applicateurs pour la radiothérapie 50 kV des cancers du rectum et de la peau Development of a new Papillon 50 TM machine with dedicated applicators used for 50 kV X-ray radiotherapy of rectal and skin cancers J.-P. Gérard a,∗ , S. Marcie b , O. Croce c , S. Hachem c , R. Trimaud b , J.-M. Bordy d ,

Abstract Objective. – Contact X-Ray 50kV (CXRT) has proven its efficiency to treat rectum and skin cancers. The goal of this technological research wasto design and produce a new CXRT machine with dedicated applicators to replace the Philips unit not any more manufactured. Materials andmethods.– The P50 was assembled in UK and the characteristics of the machine were evaluated with spectrometers, ions chambers,Gafchromic films and Monte Carlo code. The applicators were designed and manufactured in Nice. Dosimetric data were measured for eachapplicator. Validated protocols were used to treat patients. Results. – Between September 2009 and November 2011, the performances of the P50 was judged satisfactory with a dose rate close to 15Gy/mindepending on the applicator. The dose distribution was according to objectives. Clinical results achieved in 62 patients treated in centre Antoine-Lacassagne for rectum, skin or eyelid cancers confirmed the efficiency and good tolerance of CXRT. Similar results in rectal cancer were observedin Clatterbridge with 120 rectal cancers treated with P50.