Tissue activation studies with alpha-particle beams

Abstract

The positron-emitting activation of tissue by a-particle beams has been studied, using the annihilation y-ray coincidence detection technique, and the Anger positron camera.The decay spectrum in tissue following irradiation by 53 Mev a-particles from the Berkeley 88-inch cyclotron has been measured, as well a3 a visualization of the activation pattern resulting from a 910 Mev a-particle beam stopping in a tissue-like plastic phantom, a t the Berkeley 184-inch synchrocyclotron. Also studied were the activation patterns resulting from transmission of 910 MeV a-beams through a wax heed phantom, end the activation pattern in patients' heads resulting from one sitting for the pituitary ablation therapy technique. With alight improvements in resolution and sensitivity, en " on-line " positron camera technique could be useful for alignment of the end of the beam track in &eggpeak therapy with heavy charged particles. There are other novel applications which might be possible, using tissue activation techniques.

On‐line monitoring of radiotherapy beams: Experimental results with proton beams

“…Tissue activation was first discussed in detail by Tobias in 1949 7 and was first reported in gamma-ray experiments by Mayneord et al later that year. 8 Since then the radioactivity induced in tissues by photon, [8][9][10] proton, 11,12 neutron, 13 pion, [14][15][16] and heavy-ion radiotherapy beams [17][18][19] has been investigated. This induced activity has been studied as a source of patient dose, 11,20,21 as a means of determining elemental tissue composition, 10,11,13 and for determining dose distributions.…”

“…This induced activity has been studied as a source of patient dose, 11,20,21 as a means of determining elemental tissue composition, 10,11,13 and for determining dose distributions. 14,15,17,[22][23][24][25][26][27][28][29][30][31] In vivo dose localization by imaging positron-emitting nuclei is considered essential for light-ion, and radioactive-ion beam therapy. 30 Investigations of PET as a monitor for proton radiotherapy beams generally indicate that it is capable of measuring useful dosimetric, compositional, and range information.…”

Measurement of Induced Activity to Estimate Personnel Radiation Exposures Received from Accelerator Beams

“…Based upon the observation that this detector syste:n could measure very low levels of radioactivity in an i~dividual, we felt that the same technique could be applied to measure the induced radioactivities resuiting from an accidental exposure to an accelerator-produced particle beam. The activity induced 2 within the body tissues from nuclear interactions is primarily 11 c with a 20.4-min half-life, 13 N with a 9.96-min half-life, and 15 0 with a 123-sec half-life.…”

“…Table. I with the respective 11 Beam Area" gives the particle fluence (particles/cm2 greater than 20 MeV) of the exposure.…”

Proton Therapy Verification with PET Imaging

“…Using PET imaging for the verification of hadron therapy was first proposed by Maccabee et al in 196916. During an ion beam irradiation, positron emitters are produced on the beam path through nuclear fragmentation reactions, leaving a footprint of radiotracers that can be imaged with a PET scanner.…”