A superconducting cyclotron for neutron radiation therapy

Abstract

The physical and clinical specifications of a neutron therapy facility utilizing a superconducting cyclotron are presented. The cyclotron and its support system are described. Details of the operation of the cyclotron in a hospital environment are given; the requirements of the helium liquifier and cryogenic system are described together with a summary of its mode of operation. The simplicity of the cyclotron control system is discussed. The physical characteristics of the neutron beam are described. The central axis percent depth dose curve is equivalent to that of a 4 MV x-ray beam. The depth of maximum dose occurs at approximately 9 mm depth and the surface dose is between 40% and 45%. The multirod collimator allows for the production of irregularly shaped fields of size up to 26.5 x 30 cm, without excessive exposure to operating personnel.

Reducing stray radiation dose to patients receiving passively scattered proton radiotherapy for prostate cancer

“…This shield comprised two layers; the first layer (item E in figure 1) was up to 29 cm thick, and the second layer (item F in figure 1) was 6 cm thick, totaling up to 35 cm of shielding. For the final collimator (item A in figure 1), brass was replaced with tungsten alloy, a commonly used material for multi-leaf collimators (cf Maughan et al 1994, Bues et al 2005, Pönisch et al 2006, Jang et al 2006, Tacke et al 2006, Svensson et al 2007. The upstream collimator (item G in figure 1), also made of tungsten alloy, was located immediately downstream of the range-shifting plates (162 cm away from the surface of the patient and 186 cm upstream of isocenter).…”

Three dimensional conformal neutron radiotherapy for prostate cancer

“…As the studies outlined above had demonstrated a clear advantage to neutron therapy in terms of local control and survival for prostate cancer, it was our primary objective to show that this treatment could be delivered safely [8][9][10][11].…”

Gene therapy vectors containing CArG elements from the Egr1 gene are activated by neutron irradiation, cisplatin and doxorubicin

“…Neutron irradiation was conducted at the Gershenson Radiation Oncology Center (Harper Hospital, Detroit, MI) superconducting cyclotron, 30 at a dose rate of 55 cGy/min. The fast neutron facility produces a beam by accelerating 48.5 MeV deuterons onto a beryllium target.…”