Bypassing the learning curve in permanent seed implants using state-of-the-art technology.

PURPOSE: The aim of this study was to demonstrate, based on clinical postplan dose distributions, that technology can be used efficiently to eliminate the learning curve associated with permanent seed implant planning and delivery. METHODS AND MATERIALS: Dose distributions evaluated 30 days after the implant of the initial 22 consecutive patients treated with permanent seed implants at two institutions were studied. Institution 1 (I1) consisted of a new team, whereas institution 2 (I2) had performed more than 740 preplanned implantations over a 9-year period before the study. Both teams had adopted similar integrated systems based on three-dimensional (3D) transrectal ultrasonography, intraoperative dosimetry, and an automated seed delivery and needle retraction system (FIRST, Nucletron). Procedure time and dose volume histogram parameters such as D90, V100, V150, V200, and others were collected in the operating room and at 30 days postplan. RESULTS: The average target coverage from the intraoperative plan (V100) was 99.4% for I1 and 99.9% for I2. D90, V150, and V200 were 191.4 Gy (196.3 Gy), 75.3% (73.0%), and 37.5% (34.1%) for I1 (I2) respectively. None of these parameters shows a significant difference between institutions. The postplan D90 was 151.2 Gy for I1 and 167.3 Gy for I2, well above the 140 Gy from the Stock et al. analysis, taking into account differences at planning, results in a p value of 0.0676. The procedure time required on average 174.4 min for I1 and 89 min for I2. The time was found to decrease with the increasing number of patients. CONCLUSION: State-of-the-art technology enables a new brachytherapy team to obtain excellent postplan dose distributions, similar to those achieved by an experienced team with proven long-term clinical results. The cost for bypassing the usual dosimetry learning curve is time, with increasing team experience resulting in shorter treatment times.

A technical evaluation of the Nucletron FIRST system: conformance of a remote afterloading brachytherapy seed implantation system to manufacturer specifications and AAPM Task Group report recommendations.

The Fully Integrated Real-time Seed Treatment (FIRST) system by Nucletron has been available in Europe since November 2001 and is being used more and more in Canada and the United States. Like the conventional transrectal ultrasound implant procedure, the FIRST system utilizes an ultrasound probe, needles, and brachytherapy seeds. However, this system is unique in that it (1) utilizes a low-dose-rate brachytherapy seed remote afterloader (the seedSelectron), (2) utilizes 3D image reconstruction acquired from electromechanically controlled, nonstepping rotation of the ultrasound probe, (3) integrates the control of a remote afterloader with electromechanical control of the ultrasound probe for integrating the clinical procedure into a single system, and (4) automates the transfer of planning information and seed delivery to improve quality assurance and radiation safety. This automated delivery system is specifically intended to address reproducibility and accuracy of seed positioning during implantation. The FIRST computer system includes two software environments: SPOT PRO and seedSelectron; both are used to facilitate treatment planning and brachytherapy seed implantation from beginning to completion of the entire procedure. In addition to these features, the system is reported to meet certain product specifications for seed delivery positioning accuracy and reproducibility, seed calibration accuracy and reliability, and brachytherapy dosimetry calculations. Consequently, a technical evaluation of the FIRST system was performed to determine adherence to manufacturer specifications and to the American Association of Physicists in Medicine (AAPM) Task Group Reports 43, 53, 56, 59, and 64 and recommendations of the American Brachytherapy Society (ABS). The United States Nuclear Regulatory Commission (NRC) has recently added Licensing Guidance for the seedSelectron system under 10 CFR 35.1000. Adherence to licensing guidance is made by referencing applicable AAPM Task Group recommendations. In general, results of this evaluation indicated that the system met its claimed specifications as well as the applicable recommendations outlined in the AAPM and ABS reports.