Monte Carlo characterization of biocompatible beta‐emitting glass seed incorporated with the radionuclide as a SPECT marker for brachytherapy applications

Abstract

A glass seed consisting of the β−‐emitting radionuclide 90Y incorporated with radionuclide 153Sm as SPECT marker is proposed for potential application in brachytherapy in order to reduce the undesirable dose to healthy adjacent organs. The aim of this work is to determine the dosimetric characteristics, as suggested in the AAPM TG‐60/TG‐149 reports, for this seed using Monte Carlo simulation. Monte Carlo codes MCNP5, EGSnrc, and FLUKA were used to calculate the absorbed dose distribution around the seed. Dosimetric parameters, such as reference absorbed dose rate, radial dose function, and one‐dimensional (1D) and two‐dimensional (2D) anisotropy functions, were obtained. The computational results from these three codes are in agreement within 5.4% difference on average. The absorbed dose rate at the reference point was estimated to be 5.01 cGy normalh−1 μCi−1 and self absorption of YAS glass seed amounted to 30.51%. The results showed that, with thermal neutron bombardment of 5 hours in a typical flux, sufficient activity for applications in brachytherapy may be achieved. With a 5 mCi initial activity, the total dose of a YAS glass seed was estimated to be 1.38 Gy at 1.0 cm from the seed center. Comparing with gamma emitting seeds, the 90Y seed could reduce undesirable doses to adjacent organs, because of the rapid dose falloff of beta ray. Because of the high R90 value of 5.5 mm, fewer number of 90Y seeds will be required for an interstitial brachytherapy treatment using permanent implant, in comparison with other beta‐emitting seeds. The results would be helpful in the development of the radioactive implants using 90Y glass seeds for the brachytherapy treatment.PACS numbers: 87.53.Jw, 87.56.bg

Verification of Experimental Virtual Electron Source Position by Using Monte Carlo

“…In this work, the MCNP5 v1.51 Monte Carlo code [12][13][14][15][16][17][18] was employed to simulate the radiation transport of electron beams through the Siemens ONCOR Linac (Siemens Co. Germany) treatment head and water phantom based on the dimensions and materials provided by the manufacturer. The accelerator exit window, primary collimators, flattening filter, monitor chambers, Y-jaws, and X-jaws were simulated in the geometric section of the code.…”

Contactless Simultaneous Breathing and Heart Rate Detections in Physical Activity Using IR-UWB Radars

“…Due to the physical structure of human body, human breath movement leads to relative vibrations of both chest and abdomen. It is proved that the abdomen fluctuation is much stronger than the chest vibration induced by breath [ 23 ], so that several researches attempt to monitor breath for abdomen movement [ 24 , 25 ]. Based on the thoracoabdominal vibration association caused by human breath, there exist researches detecting both chest and abdominal movement simultaneously to recognize respiration pattern [ 26 ], diagnose sleep apnea–hypopnea syndrome [ 27 ], and track tumors based on breathing motions [ 28 ].…”