Secondary effects and biochemical control in patients with early prostate cancer treated with (125)-I seeds

Comparison of permanent (125)I seeds implants with two different techniques in 500 cases of prostate cancer

Purpose

To perform a comparative study of 500 consecutive ¹²⁵I seeds implants for intracapsular prostate carcinoma with two techniques differing in terms of both strand implantation and planning.

Material and methods

From 2002 to 2007 we performed 250 implants with fixed stranded seeds (RapidStrand™) and a preplanning system and from 2007 to 2010, 250 with real-time and ProLink™ system. Mean age was 68 and 66, respectively, median PSA (prostate-specific antigen) 7.3 and 7.2, stage T1-T2a in 98% and 94%, and Gleason ≤ 6 in 96% and 86%. Low risk cases were 81% and 71%. The prescribed dose was 145 Gy to the prostate volume, or 108 Gy plus EBRT 46 Gy in some intermediate risk cases. Hormonal treatment was given to 42% and 28%.

Results

Median follow-up was 48 and 47 months, respectively, 14 patients in the first group and 7 patients in the second developed biochemical failure (BF). Actuarial biochemical relapse-free survival (bRFS) at 5 years increased from 90.2% to 97.2% (low risk from 91.3% to 97.2%, intermediate risk from 84.2% to 97.1%). Biochemical failure was independent of hormone treatment. Rectal complications were G1-2 in 1.2% and 5.2%, respectively. A urinary catheter was necessary in 6.9% and 9.6%, and urethral resection in 1.9% and 4.4%. Genitourinary toxicity was G1-2 in 4.6% and 12%, G3-4 in 1.9% and 4.8%. An assessment of mean D₉₀ in a sample of patients showed that the dosimetry in postoperative planning based on CT improved from a mean D₉₀ of 143 Gy to 157 Gy.

Conclusions

The outcome of patients with low risk prostate carcinoma treated with ¹²⁵I seed is very good with low complications rate. The real-time approach in our hands achieved a more precise seed implantation, better dosimetry, and a statistically non-significant better biochemical control. We have made this our standard technique.

[Results of 125-iodine seed implant with preplanning system in 250 patients with prostate cancer]

INTRODUCTION

We review the experience with prostate carcinoma patients treated with permanent implants of 125-I seeds and the outcome eight years after the beginning of this technique.

MATERIAL AND METHODS

From 2002 to 2007 we have performed 250 implants with LDR brachytherapy with RapidStrand(®) and preplanning system. Mean age was 68 (49-78). Mean PSA was 7.32 (2.31 - 14.6). T1-T2a was the stage in 98%, and Gleason ≤ 6 in 96%. Low risk cases were 81% and intermediate risk 19% (ten of them received 46 Gy EBRT). Hormonal treatment was used in 42%.

RESULTS

With a mean follow-up of 48 months, 14 patients (5.7%) showed biochemical failure (BF). Eleven patients (4.5%) with theoretical BF were observed and PSA decreased without treatment. Actuarial PSA relapse-free survival at 5 years was 91%, (92% low risk, 86% intermediate cases), and 92% vs 81% with PSA <10 vs >10 (p<0.05). Rectum complications were G2 in 0.6%. A urinary catheter was necessary in 6.5%. Sexual function was conserved in 60%. Mean V100 was 89% and D90 143 Gy.

CONCLUSION

The outcome of patients with low risk prostate carcinoma treated with I-125 seed is very good with very low complications rate. Cases with PSA bounces should be controlled before starting a salvage treatment.