Production of intense mass separated 11C beams for PET-aided hadron therapy

Abstract

A novel production system based on the Isotope Separation On-Line (ISOL) method is being developed to produce intense mass separated 11 C beams for PET-aided hadron therapy. In this work, we present a systematic study of the target that was developed for optimized 11 C beam production. A solid boron nitride target (BN) with approximately 21% open porosity was manufactured by spark plasma sintering to provide maximized in-target production yield with enhanced isotope release properties. Operational limitations with respect to high temperatures and oxidizing atmospheres were studied, revealing that the BN target can withstand temperatures up to 1500 • C and can be operated with a controlled O 2 leak, providing O 2 potentials up to −300 kJ/mol, measured at 1000 • C.

CERN-MEDICIS: A Review Since Commissioning in 2017

“…Beamtime was devoted to nine different approved projects through the year. It included several developments within the MEDICIS-Promed European Commission Marie Sklodowska-Curie innovative training program with, as examples, the successful separation of Er-169 from externally irradiated Er-168 (13,14) as feasibility tests in preparation for LS2, as well as promising C-11 diffusion studies (19). In total, 5.5 × 10 19 protons have been directed to the ISOLDE HRS target station in 2018, among which 44% could be exploited for the MEDICIS program (i.e., 2.4 × 10 19 protons).…”

A porous hexagonal boron nitride powder compact for the production and release of radioactive 11C

“…Within MEDICIS-Promed [12], new accelerator systems based on the Isotope Separation On-Line (ISOL) method are being developed, tailored for 11 C beam production [13], manipulation and post-acceleration [14,15]. To meet the requirements for effective treatments, i.e.…”

“…intense and pure RIBs, and furthermore, to implement a 11 C-based protocol into existing facilities, optimization along the accelerator chain is essential. For the production of intense mass separated 11 C beams, a porous hexagonal boron nitride (BN) ISOL-type target has been developed [13]. Boron-comprising targets are prominent because of the high nuclear reaction cross section 11 B(p,n) 11 C, enabling increased in-target production yields.…”

“…small grain sizes and high open porosity, for fast diffusion and effusion processes; secondly, molecular isotope extraction in the form of 11 CO is considered due to higher volatility and reduced reactivity with surrounding surfaces. While this target has been characterized and tested with respect to its high-temperature stability and hightemperature oxidation behavior, previous attempts to gain insight into the 11 C release characteristics by doping BN powder with stable carbon prior pre-sintering, yielded no conclusive results [13]. Consequently, we report in this work the results of a carbon release study from activated BN pellets that was performed at CERN MEDICIS [17].…”

Challenges in 11C charge breeding

“…When using 11 C (β + emitter, = 20.4 min) as the primary treatment beam in hadron therapy, one can benefit from its excellent properties for both on-line and off-line PET imaging, which can be used for dose verification [2]. While ions are produced abundantly in conventional hadron therapy with stable carbon, it is highly challenging to provide a radioactive beam of adequate intensity for treatment [3]. In this paper it is assumed that the radioactive treatment ions are produced by the Isotope Separation On-Line (ISOL) technique.…”