Citation Export Print. Javascript must be enabled for narrowing. Results 1 - 1 of 1. Search took: 0. Ytterbium Yb : a new brachytherapy source. Preliminary report on a phase I-II study. Montemaggi, P. Citation Export Print Permalink Translate. Abstract Abstract. Cuore in Rome Italy , a phase I-II clinical trial aimed to evaluate the real possibilities for a clinical use of Yb as a brachytherapy source was designed. Two main problems were identified and solved preliminarily. First, we made the seeds Amersham prototipe 6 were made visible to x-rays, modifying the chemical composition of the actual sources.
At the same time, a validation of the dosimetric data available at that time was carried out by our physicists, that allowed a proper dosimetry and defined the rules for provisional and actual dosimetric planning. The trial includes 16 pts affected by extensive primary or recurrent cancers, suitable for brachytherapy, with accessible, measurable lesions and with a life expectancy longer than 6 months. We treated so far 8 pts, which are evaluated in this study, including a prostate cancer, a chest wall recurrence from breast primary, one vaginal relapse from endometrium, one base of the tongue, three lips and one nodal relapse from a previously treated cancer of the mobile tongue.
The dosimetric analysis included an evaluation of dose volume histograms Coverage Index, Relative Dose Homogeneity Index, Overdosage Volume Index, External Volume Index which were compared with those obtainable from identical implants with Ir and I.
As clinical end points we looked at the shrinking of the tumor and acute side effects. Radiation protection and safety parameters were taken into account and evaluated. Technical feasibility and cost benefit ratio were also analysed and discussed. Results There were no technical problems in performing the implants. Complete responses were seen in 5 out of 8 pts, as expected also with the standard brachytherapy procedures and sources, and three pts experienced partial responses.
The tolerance of the treatment was good, but the mucositis tended to be more severe than with Ir, probably because of specific physical characteristic of Yb. Analysis of dose volume histograms showed an advantage of Yb in 3 out of four parameters. Radiation safety was very good with very simple rules for protection, not dissimilar from those with I and definitely easier and less expensive in comparison to Ir.
Conclusions Preliminary data from this trial suggest a possible role for Yb in clinical practice Biological and physical considerations indicate that this agent has some advantages which this preliminary analysis of clinical data seem to confirm.
Country of publication. AND OR. Add Another. Standard Search Advanced Search. Limit to results with full text. Select All Expand All. Collapse All. Citation Export Print. Javascript must be enabled for narrowing. Results 1 - 1 of 1. Search took: 0. Yb gamma-ray sources made from natural ytterbium and their characteristics. Citation Export Print Permalink Translate. Abstract Abstract. The attenuation curves and the penetrameter sensitivity curves of Yb were measured and were compared with that of Ir Yb is useful gamma-ray source for the inspection of welds on thin plates or small diameter pipes.
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