Evaluation of Bremsstrahlung radiation dose in stereotactically radiocolloid therapy of cystic craniopharyngioma tumors with 32P radio-colloid

Abstract

Over 90% of craniopharyngeal brain tumors are cystic, which enables the injection of beta emitters such as phosphorus-32 (P) radio-colloid into cysts for their treatment. The aim of this study was to evaluate the clinical and theoretical modelling of Bremsstrahlung radiation dose resulting from stereotactic radio-colloid therapy of cystic craniopharyngioma tumors with P.P radio-colloid with appropriate activity concentration was injected to a head phantom, and then the Bremsstrahlung radiation spectrum and planar images were obtained using a gamma camera. Both phantom and gamma camera were simulated using MCNPX code, and the results were compared with practical results. Bremsstrahlung radiation spectrum was measured using a handheld gamma spectrometer for two patients treated with stereotactic radio-colloid therapy with P in different positions and compared to Monte Carlo simulation. Results of counting and determining sensitivity coefficients in the air and the attenuating environment were obtained. Also, comparing the counting sensitivity from practical and simulation methods indicated the agreement of the data between the two methods. Comparison of the spectra from different positions around patient's head indicated the ability to use this detector to quantify the activity in the operating room. Selection of the spectrum is important in Bremsstrahlung radiation imaging. We can take advantage of spectrometry measurement using gamma camera, handheld gamma spectrometer for patient, and theoretical modeling with Monte Carlo code to evaluate radiopharmaceutical distribution, leakage, as well as estimate activity and predict therapeutic effects in other adjacent structures and ultimately optimize radio-colloid therapy in cystic craniopharyngeal patients.

Radiation safety aspects of 90Y bremsstrahlung radiation produced from radiation shielding apparatus using the Monte Carlo simulation

“…Sev eral tally op tions are avail able in the MCNP5. The F8 tally was used in this study be cause it pro vides the bremsstrah lung en ergy dis tri bu tion with the pulse unit [18]. Rel a tive er rors of MCNP5 re sults in this work were lim ited within 10 % by suf fi ciently in creas ing the num bers of sim u lat ing par ti cles.…”

A Systematic Review of Simulation-Based Training in Neurosurgery, Part 1: Cranial Neurosurgery

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