Abstract
Purpose
To analyze the difference in prostate coverage and dose to the rectum in men with
prostate carcinoma treated with permanent seed brachytherapy with different seed activities.
Methods
Forty-nine patients treated with iodine-125 permanent seed prostate brachytherapy
with low-activity seeds of 0.30–0.37 mCi were identified. For each of these patients,
2 patients with similar prostate volume (±2 cc) were paired: one treated with intermediate
seed activity (0.44–0.46 mCi) and one with high seed activity (0.60–0.66 mCi). The
doses to prostate and rectum were compared using CT on Day 30.
Results
A total of 147 patients divided into the three seed activity groups were analyzed.
Mean prostate volume was 35.7 cc (standard deviation [SD], 11.70). Compared with low-activity
seeds, implants with high-activity seeds consisted of an average of 22 seeds and 4.7
needles less. The dose to the prostate (prostate volume receiving 100% of the prescribed
dose [V100], prostate volume receiving 150% of the prescribed dose, and minimal dose covering
90% of the prostate volume expressed in Gy) was not higher on Day 30 (p = 0.58–0.97). The mean volume (in cubic centimeters) of rectal wall receiving 100%
of the prescribed dose (V100) increased with activity: low activity, 0.34 cc (SD, 0.49), intermediate activity,
0.47 cc (SD, 0.48), and high activity, 0.72 cc (SD, 0.79) (p = 0.009). There was a trend (p = 0.073) toward a higher frequency of clinically unfavorable rectal dosimetry (V100 > 1.3 cc) in patients with high-activity seeds (16.7%) compared with low-activity
(6.3%) or intermediate-activity (4.2%) seeds.
Conclusion
High-activity seeds do not result in a higher dose to the prostate but in a higher
dose to the rectum.
Keywords
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References
- Comparison between high and low source activity seeds for I-125 permanent seed prostate brachytherapy.Int J Radiat Oncol Biol Phys. 2010; 78: 781-786
- Randomized trial of high- and low-source strength (125)I prostate seed implants.Int J Radiat Oncol Biol Phys. 2005; 61: 44-51
- Multi-institutional analysis of long-term outcome for stages T1-T2 prostate cancer treated with permanent seed implantation.Int J Radiat Oncol Biol Phys. 2007; 67: 327-333
- The Quadrella: A novel approach to analyzing optimal outcomes after permanent seed prostate brachytherapy.Radiother Oncol. 2014; 111: 110-113
- Inter-institutional variation of implant activity for permanent prostate brachytherapy.Brachytherapy. 2008; 7: 297-300
- Permanent prostate implant using high activity seeds and inverse planning with fast simulated annealing algorithm: A 12-year Canadian experience.Int J Radiat Oncol Biol Phys. 2007; 67: 334-341
- American Brachytherapy Society consensus guidelines for transrectal ultrasound-guided permanent prostate brachytherapy.Brachytherapy. 2012; 11: 6-19
- Results of permanent prostate brachytherapy, 13 years of experience at a single institution.Radiother Oncol. 2004; 71: 23-28
- Outcomes following iodine-125 brachytherapy in patients with Gleason 7, intermediate risk prostate cancer: A population-based cohort study.Radiother Oncol. 2012; 103: 228-232
- 10-year experience with I-125 prostate brachytherapy at the Princess Margaret Hospital: Results for 1,100 patients.Int J Radiat Oncol Biol Phys. 2011; 80: 1323-1329
- A comprehensive review of CT-based dosimetry parameters and biochemical control in patients treated with permanent prostate brachytherapy.Int J Radiat Oncol Biol Phys. 2001; 50: 605-614
- Defining the risk of developing grade 2 proctitis following 125I prostate brachytherapy using a rectal dose-volume histogram analysis.Int J Radiat Oncol Biol Phys. 2001; 50: 335-341
- Pre- and post-implant dosimetry: An inter-comparison between UK prostate brachytherapy centres.Radiother Oncol. 2003; 66: 181-183
- Health-related quality of life after permanent I-125 brachytherapy and conformal external beam radiotherapy for prostate cancer—A matched-pair comparison.Radiother Oncol. 2009; 91: 225-231
- Actas Urol Esp. 2011; 35 ([in Spanish]): 339-344
- Initial analysis of Pro-Qura: A multi-institutional database of prostate brachytherapy dosimetry.Brachytherapy. 2007; 6: 9-15
Article info
Publication history
Published online: January 24, 2015
Accepted:
November 24,
2014
Received in revised form:
November 19,
2014
Received:
September 12,
2014
Footnotes
Conflict of interest notification: There is no conflict of interest.
Identification
Copyright
© 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.
