American Brachytherapy Society recommends no change for prostate permanent implant dose prescriptions using iodine-125 or palladium-103

Abstract 

Purpose

In 2004, the American Association of Physicists in Medicine (AAPM) issued a report outlining recommended ¹²⁵I and ¹⁰³Pd datasets for consistency in calculating brachytherapy dose distributions. In 2005, to aid evaluating the clinical impact of implementing these datasets, the AAPM assessed the historical dependence of how prescribed doses differed from administered doses for ¹²⁵I and ¹⁰³Pd for permanent implantation of the prostate. Consequently, the American Brachytherapy Society (ABS) considered the nature of these changes towards issuing recommended dose prescriptions for ¹²⁵I and ¹⁰³Pd interstitial brachytherapy implants for monotherapy and standard boosts.

Methods and materials

An investigation was performed of the 2005 AAPM analysis to determine changes in administered dose while affixing prescribed dose using 2004 AAPM ¹²⁵I and ¹⁰³Pd brachytherapy dosimetry datasets for prostate implants. For ¹²⁵I and ¹⁰³Pd, administered dose would change by +1.4% and +4.2%, respectively. The biological and societal impact of changing prescribed dose was considered.

Results

Based on the need for clinical constancy and in recognition of overall uncertainties, the ABS recommends immediate implementation of the 2004 AAPM consensus brachytherapy dosimetry datasets and no changes to ¹²⁵I and ¹⁰³Pd dose prescriptions at this time.

Conclusions

Radiation oncologists should continue to prescribe monotherapy doses of 145Gy and 125Gy for ¹²⁵I and ¹⁰³Pd, respectively, and standard boost doses of 100-110Gy and 90-100Gy for ¹²⁵I and ¹⁰³Pd, respectively.

Keywords: ABS guidelines, Prostate brachytherapy, Dosimetry, ¹²⁵I, ¹⁰³Pd, Prescription