Results for Palladium Seed Implant for T1, T2 Prostate Cancer
Patients with favorable prostate cancer (Gleason of 6 or less and PSA less than 10, may do well with seed implants alone (called monotherapy).) Blasko recently reported the Seattle results for palladium seed implants for early stage prostate cancer. Patients were treated with seeds only (11,500cGy dose, avg. volume 30cc, avg. number of seeds 91, median activity was 122mCi.) None of the patients received external beam or hormonal therapy. The overall biochemical (i.e. normal PSA) control rate at 9 years was 83.5% from Blasko IJROBP 2000;46:839. Their results with I-125 alone were 87% at 10 years (Grimm IJROBP 200151;34. see below) Higher risk patients need external plus seeds (see Datoli below.) Even with early stage disease and favorable Gleason scores (i.e. 6 or lower) and higher PSA leads to poor results with seeds only (see Grimm data.)
Control Rates with Palladium Seed Implant Only
Number Risk Factors Controlled at 5 Years
None 94%
One 87%
Both 65%

Risk Factors: Gleason 7 or higher or PSA > 10

Control Rates by Gleason Score
Gleason Score Controlled at 5 Years
3 - 4 89%
5 - 6 92%
7 75%
8 - 10 86%

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Control Rates by PSA Level
PSA Level Controlled at 5 Years
0 - 4 90%
4 - 10 88%
10 - 20 80%
> 20 67%

1 Contrast the results with seeds alone with other studies than combine external beam irradiation with seeds (see the two papers below)

 
Int J Radiat Oncol Biol Phys 2000 Mar 1;46(4):839-50

Palladium-103 brachytherapy for prostate carcinoma.

Blasko JC, Grimm PD, Sylvester JE, Badiozamani KR, Hoak D, Cavanagh W

Seattle Prostate Institute, Seattle, WA, USA.

Purpose: A report of biochemical outcomes for patients treated with palladium-103 (Pd-103) brachytherapy over a fixed time interval. Methods and Materials: Two hundred thirty patients with clinical stage T1-T2 prostate cancer were treated with Pd-103 brachytherapy and followed with prostate-specific antigen (PSA) determinations. Kaplan-Meier estimates of biochemical failure on the basis of two consecutive elevations of PSA were utilized. Multivariate risk groups were constructed. Aggregate PSA response by time interval was assessed.Results: The overall biochemical control rate achieved at 9 years was 83.5%. Failures were local 3.0%; distant 6.1%; PSA progression only 4.3%. Significant risk factors contributing to failure were serum PSA greater than 10 ng/ml and Gleason sum of 7 or greater. Five-year biochemical control for those exhibiting neither risk factor was 94%; one risk factor, 82%; both risk factors, 65%. When all 1354 PSA determinations obtained for this cohort were considered, the patients with a proportion of PSAs </= 0.5 ng/ml continued to increase until at least 48 months post-therapy. These data conformed to a median PSA half-life of 96.2 days.Conclusions: Prostate brachytherapy with Pd-103 achieves a high rate of biochemical and clinical control in patients with clinically organ-confined disease. PSA response following brachytherapy with low-dose-rate isotopes is protracted.

10-year biochemical (prostate-specific antigen) control of prostate cancer with 125I brachytherapy
Peter D. Grimm, John C. Blasko, John E. Sylvester, Robert M. Meier, William Cavanagh

To report 10-year biochemical (prostate-specific antigen [PSA]) outcomes for patients treated with 125I brachytherapy as monotherapy for early-stage prostate cancer. One hundred and twenty-five consecutively treated patients, with clinical Stage T1-T2b prostate cancer were treated with 125I brachytherapy as monotherapy, and followed with PSA determinations. Kaplan-Meier estimates of PSA progression-free survival (PFS), on the basis of a two consecutive elevations of PSA, were calculated. Results: The overall PSA PFS rate achieved at 10 years was 87% for low-risk patients (PSA < 10, Gleason Sum 2–6, T1-T2b).

Int J Radiat Oncol Biol Phys 1996 Jul 15;35(5):875-9

103Pd brachytherapy and external beam irradiation for clinically localized, high-risk prostatic carcinoma.

Dattoli M, Wallner K, Sorace R, Koval J, Cash J, Acosta R, Brown C, Etheridge J, Binder M, Brunelle R, Kirwan N, Sanchez S, Stein D, Wasserman S

Department of Radiology, University Community Hospital, Tampa, FL 33613, USA.

PURPOSE: To summarize biochemical failure rates and morbidity of external beam irradiation (EBRT) combined with palladium (103Pd) boost for clinically localized high-risk prostate carcinoma. METHODS AND MATERIALS: Seventy-three consecutive patients with stage T2a-T3 prostatic carcinoma were treated from 1991 through 1994. Each patient had at least one of the following risk factors for extracapsular disease extension: Stage T2b or greater (71 patients), Gleason score 7-10 (40 patients), prostate specific antigen (PSA) > 15 (32 patients), or elevated prostatic acid phosphatase (PAP) (17 patients). Patients received 41 Gy EBRT to a limited pelvic field, followed 4 weeks later by a 103Pd boost (prescription dose: 80 Gy). Biochemical failure was defined as a PSA greater than 1.0 ng/ml (normal < 4.0 ng/ml). Patients whose PSA was still decreasing at the last follow-up were censored at that time. Patients whose PSA plateaued at a value greater than 1.0 were scored as failures at the time the PSA first plateaued. RESULTS: The overall, actuarial freedom from biochemical failure at 3 years after treatment was 79%. In Cox proportional hazard multivariate analysis, the strongest predictor of failure was elevated acid phosphatase (p = 0.04), followed by PSA (p = 0.17), Stage (p = 0.23), and Gleason score (p = 0.6). Treatment-related morbidity was usually limited to temporary, RTOG Grade 1-2 urinary symptoms. One patient, who had both a transurethral incision of the prostate (TUIP) and a transurethral resection of the prostate (TURP), developed low-volume urinary incontinence. The actuarial potency rate at 3 years after implantation was 77% for 46 patients who were sexually potent prior to implant. CONCLUSION: Biochemical freedom from failure rates following combined EBRT and 103Pd brachytherapy for clinically localized, high-risk prostate cancer compare favorably with that reported after conventional dose EBRT alone. Morbidity has been acceptable.

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