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Candela-Juan, C., Ballester, F., Perez-Calatayud, J., & Vijande, J. (2015). Assaying multiple I-125 seeds with the well-ionization chamber SourceCheck(4 Pi) 33005 and a new insert. J. Contemp. Brachytherapy, 7(6), 492–496.
Abstract: Purpose: To provide a practical solution that can be adopted in clinical routine to fulfill the AAPM-ESTRO recommendations regarding quality assurance of seeds used in prostate permanent brachytherapy. The aim is to design a new insert for the well-ionization chamber SourceCheck(4 Pi) 33005 (PTW, Germany) that allows evaluating the mean air-kerma strength of up to ten I-125 seeds with one single measurement instead of measuring each seed individually. Material and methods: The material required is: a) the SourceCheck(4 Pi) 33005 well-ionization chamber provided with a PTW insert to measure the air-kerma strength S-K of one single seed at a time; b) a newly designed insert that accommodates ten seeds in one column, which allows measuring the mean S-K of the ten seeds in one single measurement; and c) a container with ten seeds from the same batch and class of the seeds used for the patient implant, and a set of nine non-radioactive seeds.The new insert is characterized by determining its calibration coefficient, used to convert the reading of the well-chamber when ten seeds are measured to their mean S-K. The proposed method is validated by comparing the mean S-K of the ten seeds obtained from the new insert with the individual measurement of S-K of each seed, evaluated with the PTW insert. Results: The ratio between the calibration coefficient of the new insert and the calibration coefficient of the PTW insert for the SourceCheck(4 Pi) 33005 is 1.135 +/- 0.007 (k = 1). The mean S-K of a set of ten seeds evaluated with this new system is in agreement with the mean value obtained from measuring independently the S-K of each seed. Conclusions: The new insert and procedure allow evaluating the mean S-K of ten seeds prior to the implant in a single measurement. The method is faster and more efficient from radiation protection point of view than measuring the individual S-K of each seed.
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Oliver-Cañamas, L., Vijande, J., Candela-Juan, C., & Perez-Calatayud, J. (2025). Dosimetry audits in high dose rate brachytherapy: A survey on the current scenario in Europe. Phys. Medica, 136, 105047–7pp.
Abstract: Introduction: This work aims to study the current scenario of dosimetry audits in high dose rate (HDR) brachytherapy (BT) in Europe to evaluate whether there is a need to implement more services of this type and to define the characteristics that they should meet according to users. Material and methods: A survey consisting of 30 multiple choice questions was designed and distributed among European centers. The estimated time to answer was less than 15 min. 74 HDR BT centers participated, having 192Ir, 60Co and/or electronic sources. Information about users' opinions and experience with dosimetry audits in this field, center resources and quality assurance (QA) procedures was gathered. Results: For 61 % of users, dosimetry audits in HDR BT should be recommended, but not mandatory, whereas 35 % suggested that they are necessary and should be compulsory. Only for 4 % of participants these audits are not necessary. In contrast, 86 % of users found that the current number of these services is inadequate and that more national and/or international services are needed. Most participants operate according to QA recommendations of published guidelines, with exceptions, such as the use of the Reference Air Kerma Rate provided by the manufacturer instead of the one measured by the home medical physicist. Conclusion: The number of HDR BT dosimetry audits available to users is inadequate and there is a need to implement more national and/or international services of this type. Some technical aspects that an audit of this type should fulfill are outlined in this work.
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