Print
| Title: | Improved
Biochemical Control and Clinical Disease-Free Survival with Intraoperative
Versus Preoperative Preplanning for Transperineal Interstitial Permanent
Prostate Brachytherapy |
| Author(s): | Jinesh N. Shah, MD,a Cheng-Shie Wuu, PhD,a
Aaron E. Katz, MD,b Joseph L. Laguna, CMD, RTT,a Mitchell C. Benson,
MD,b Ronald D. Ennis, MD,a |
| Lay Summary: | In this study, the authors compare their newer prostate seed implant technique to the standard prostate seed implant technique. In their newer technique, the planning of the seed implant is performed in the operating room while the patient is already under anesthesia. In this way, there can be no change in prostate, shape or position between planning and execution of the seed implant. The authors show a superior outcome ( 96% of patients free of cancer recurrence) with this newer technique. |
| Purpose: | We hypothesized that intraoperative preplanning
for transperineal interstitial permanent prostate brachytherapy
may yield better prostate cancer control than preoperative preplanning.
We tested this hypothesis by comparing treatment outcomes of patients who underwent implantation using these two preplanning methods. |
| Patients & Methods: | We analyzed the data of 135 consecutive patients
with localized prostate cancer treated from 1996 to 2001 with transperineal
interstitial permanent prostate brachytherapy ± preimplantation
hormonal therapy: 42 received preoperative preplanning (group 1), and 93 underwent intraoperative preplanning (group 2). Biochemical status was assessed using two failure definitions: American Society for Therapeutic Radiology and Oncology (ASTRO) (three consecutive rises in prostate-specific antigen level) and Houston (prostate-specific antigen level current nadir + 2 ng/mL). Clinical disease-free survival and postimplantation dosimetry were also examined. |
| Results: | All disease control outcomes were superior for
group 2. The 4-year ASTRO biochemical no evidence of disease rate
was 80% for group 1 versus 94% for group 2. The 4-year Houston biochemical
no evidence of disease rate was 82% for group 1 versus 96% for group 2. The 4-year clinical diseasefree survival rate was 87% for group 1 versus 99% for group 2. Preplanning method (preoperative versus intraoperative) remained predictive of disease control outcomes in multivariate analyses with the covariates of pretreatment prostate-specific antigen level, Gleason score, clinical stage, and case sequence number (proxy for brachytherapist experience and “stage migration”). Dosimetric prostate coverage was superior for group 2. The mean percentage of the prescription dose delivered to 90% of the prostate volume (%D90) was 75% for group 1 versus 90% for group 2. A %D90 = 70% predicted for improved disease control; fewer group 1 than 2 patients met this dosimetric criterion (55% versus 87%). |
| Conclusion: | In this analysis, we demonstrated that patients
treated with intraoperative preplanning had better ASTRO biochemical
control, Houston biochemical control, and clinical DSF than patients treated with preoperative preplanning. In addition, superior postimplantation dosimetric prostate coverage was achieved with intraoperative than with preoperative preplanning. Better dosimetric target coverage likely contributed, at least in part, to the superior disease control achieved with intraoperative preplanning in this study. Although not compulsory for achieving excellent TIPPB outcomes, intraoperative preplanning nonetheless may offer an efficacious means of improving dosimetric prostate coverage and thereby disease control outcomes for those brachytherapists who are achieving suboptimal results with preoperative preplanning. |
Copyright © 2006