In Vivo Beam Localization by Positron Activation in Pion Therapy

Mausner, L.F.; Moinester, M. A.; Knight, J.D.; Cochavi, S.; Friedland, Stephen S.

doi:10.2307/3575112

Cited by 5 publications

(35 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…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.…”

Section: Introductionmentioning

confidence: 99%

“…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.…”

Section: Introductionmentioning

confidence: 99%

“…Experiments were conducted with 150 MeV continuous and macro-pulsed proton beams which had beam currents ranging from 0.14 nA to 1.75 nA. The production and decay of short-lived isotopes, 15 O and 14 O, was studied using 1 min irradiations with a continuous beam. These isotopes provide a significant signal on short time scales, making on-line imaging possible.…”

mentioning

confidence: 99%

“…The dose delivered to the patient may also be monitored by observing the increase in the number of coincidence events detected between successive beam pulses. Over 80% of the initial positron-emitting activity is from 15 O while the remainder is primarily 11 C, 13 N, 14 O with traces of 18 F, and 10 C. Radioisotopic imaging may also be performed along the beam path by fitting decay data collected after the treatment is complete. Using this technique, it is shown that variations in elemental composition in inhomogenous treatment volumes may be identified and used to locate anatomic landmarks.…”

mentioning

confidence: 99%

See 3 more Smart Citations

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

et al. 1999

View full text Add to dashboard Cite

Proton radiotherapy is a powerful tool in the local control of cancer. The advantages of proton radiotherapy over gamma-ray therapy arise from the phenomenon known as the Bragg peak. This phenomenon enables large doses to be delivered to well-defined volumes while sparing surrounding healthy tissue. To fully realize the potential of this technique the location of the high-dose volume must be controlled very accurately. An imaging system was designed and tested to monitor the positron-emitting activity created by the beam as a means of verifying the beam's range, monitoring dose, and determining tissue composition. The prototype imaging system consists of 12 pairs of cylindrical BGO detectors shielded in lead. Each crystal was 1.9 cm in diameter, 5.0 cm long, and separated by 0.5 cm from other detectors in the row. These are arranged in two rows, 60 cm apart, with the proton beam and tissue phantoms half-way between and parallel to the detector rows. Experiments were conducted with 150 MeV continuous and macro-pulsed proton beams which had beam currents ranging from 0.14 nA to 1.75 nA. The production and decay of short-lived isotopes, 15O and 14O, was studied using 1 min irradiations with a continuous beam. These isotopes provide a significant signal on short time scales, making on-line imaging possible. Macro-pulsed beams, having a period of 10 s, were used to study on-line imaging and the production and decay of long-lived isotopes, 13N, 11C, and 18F. Decay data were acquired and on-line images were obtained between beam pulses and indicate that range verification is possible, for a 150 MeV beam, after one beam pulse, to within the 1.2 cm resolution limit of the imaging system. The dose delivered to the patient may also be monitored by observing the increase in the number of coincidence events detected between successive beam pulses. Over 80% of the initial positron-emitting activity is from 15O while the remainder is primarily 11C, 13N, 14O with traces of 18F, and 10C. Radioisotopic imaging may also be performed along the beam path by fitting decay data collected after the treatment is complete. Using this technique, it is shown that variations in elemental composition in inhomogenous treatment volumes may be identified and used to locate anatomic landmarks. Radioisotopic imaging also reveals that 14O is created well beyond the Bragg peak, apparently by secondary neutrons.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

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

et al. 1999

View full text Add to dashboard Cite

show abstract

“…Let us call this intensity R(xo,yo) (2) In the case of a CT scan this value is proportional to the calculated x -ray absorption coefficients. Thus…”

Section: Cellular Array Processor For Computer Generating the Hologrammentioning

confidence: 99%