A study by Peschel suggested that Palladium had a lower rate of
complications then Iodine:
Long-term complications with prostate implants: iodine-125 vs. palladium-103.
Peschel RE, Chen Z, Roberts K, Nath R. Radiat Oncol Investig 1999;7(5):278-88
Related Articles, Links
Department of Therapeutic Radiology, Yale University School of Medicine, New Haven,
Connecticut 06520-8040, USA. richard.peschel@yale.edu
A review of 123 early stage T1c and T2 prostate cancer patients implanted at Yale
University with I-125 (82 patients) or Pd-103 (41 patients) reveals a significantly lower overall complication rate with Pd-103 (0%) vs. I-125 (13%).
Most important, the grade III-IV complication rate for Pd-103 was 0% vs. 6% for I-125. The
3-year actuarial probability of remaining free of a long-term complication was 100% for
Pd-103 vs. 82% for I-125 (P<0.01). A review of the literature
for 992 patients implanted with I-125 vs. 540 patients implanted with Pd-103 shows a
consistently higher complication rate for I-125 vs. Pd-103. Assuming that the
MTD for Pd-103 may be increased to produce an equivalent late-reacting normal tissue BED
to that for I-125, then the radiobiology model predicts the log10 cell kill for Pd-103
implant will be greater than that of an I-125 implant for all tumor doubling times
(high-grade tumors and low-grade tumors). The implications of these findings are discussed
in terms of future research directions for prostate implants.
Another study from Seattle
showed the results were the same for both isotopes
125I versus 103Pd for low-risk prostate
cancer: preliminary PSA outcomes from a prospective randomized multicenter trial
Kent Wallner .IJROBP 2003:57:1297
Of a planned total of 600 patients with 1997 American Joint Committee on Cancer clinical
Stage T1c–T2a prostate carcinoma (Gleason score 5–6, prostate-specific antigen
[PSA] 4–10 ng/mL), 126 were randomized to implantation with 125I
(144 Gy) vs. 103Pd (125 Gy). The prostate biopsies were reviewed for
Gleason score by one of us (L.T.). A single manufacturer of 125I sources (Model
6711, Amersham, Chicago, IL) and 103Pd sources (Theraseed, Theragenics, Buford,
Georgia) was used. Isotope implantation was performed with standard techniques, using a
modified peripheral loading pattern. Of a total of 126 patients randomized, 11 were
excluded, leaving 115 randomized patients for this analysis. Twenty patients received a
short course of preimplant hormonal therapy, none of whom continued hormonal therapy after
their implant procedure. Postimplant CT was obtained 2–4 hours after implantation. The dosimetric parameters analyzed included the percentage of the
postimplant prostate or rectal volume covered by the prescription dose (V100)
and the dose that covered 90% of the postimplant prostate volume (D90).
Freedom from biochemical failure was defined as a serum PSA level =0.5 ng/mL at last
follow-up. Patients were censored at last follow-up if their serum PSA level was still
decreasing. Patients whose serum PSA had reached a nadir at a value >0.5 ng/mL were
scored as having failure at the time at which their PSA had reached a nadir. The follow-up
period for patients without failure ranged from 2.0 to 4.9 years (median 2.9).
Freedom-from-failure curves were calculated by the Kaplan-Meier method. Differences
between groups were determined by the log–rank method.
Results: The
actuarial biochemical freedom-from-failure rate at 3 years was 89% for 125I
patients vs. 91% for 103Pd patients (p = 0.76). The 3-year biochemical
freedom-from-failure rate for patients with a D90 <100% of the prescription
dose was 82% vs. 97% for patients with a D90 =100% of the prescription dose (p
= 0.01). Similarly, the 3-year biochemical freedom-from-failure rate for patients with a V100
<90% of the prescription dose was 87% vs. 97% for patients with a V100 =90%
of the prescription dose (p = 0.01). The effect of the dosimetric parameters on
biochemical control was most pronounced for 125I, but also apparent for 103Pd.
Conclusion
: The 3-year actuarial biochemical control rates for low early-stage prostate cancer are
similar after 125I and 103Pd.
| Title: Iodine 125 Versus Palladium 103
Implants for Prostate Cancer: Clinical Outcomes and Complications |
| Author(s): Richard E. Peschel ; John W.
Colberg ; Zhe Chen ; Ravinder Nath ; Lynn D. Wilson (Yale) |
| Source: The Cancer Journal
2004; Volume: 10 Number: 3 Page: 170 -- 174 |
|
Abstract: Purpose: The purpose of this
study was to evaluate the clinical outcomes and compare complication rates for patients
with prostate cancer treated with iodine 125(125I) and palladium 103(103Pd)
prostate brachytherapy at a single institution.
Patients and Methods: Between 1992 and 2002, 272 patients with prostate cancer were
treated with ultrasound-guided transperineal implantation incorporating 125I
(107 patients) or 103Pd (165 patients). T hree months of hormonal therapy was
incorporated into the treatment program in 33% of the patients in both groups. Nineteen
percent of those treated with 125I were treated with a combination of
implantation plus external-beam radiation therapy. Only 6% of the group receiving 103Pd
implants were treated with such a combi- nation. For those treated with 125I
implantation alone, the minimum tumor dose was 145 Gy. The minimum tumor dose for those
treated with < sup>103Pd alone was 125 Gy. Those treated with a combination of
external-beam radiation therapy and 125I received 45 Gy via 1.8-Gy fractions
followed by implantation with a minimum tumor dose of 110 Gy. For those treated with
external-beam radiation therapy and 103Pd, the doses were 45 Gy via 1.8-Gy
fractions followed by implantation with minimum tumor dose of 98 Gy. Outcomes were
evaluated based on radionuclide used, T stage, Gleason score, prostate-specific antigen,
and p rognostic group. Complications were also evaluated for each radionuclide. The mean
follow-up for the 125I group was 55 months, and the range was 12-108 months.
The mean follow-up for the 103Pd group was 44 months, and the range was 12-72
months.
Results: The 5-year biochemical disease-free survival rates for
those in the favorable group (clinical stage T1c or T2, prostate-specific antigen level
<10, Gleason score <7) were 92% for the < sup>125I group and 92% for the
patients treated with 103Pd. The 5-year disease-free survival rates for those
in the intermediate and poor prognostic groups, which were combined, was 72% and 74%,
respectively, for 125I and 103Pd. There was no
statistically significant difference for either modality for any treatment group tested.
In those treated with implantation alone, patients treated with 125I had higher
complication rates than those treated with < sup>103Pd (15% vs 4%). 125I-treated
patients had a grade 2 complication rate of 8% and a grade 3-4 complication rate of 7%,
compared with 3% and 1%, respectively, for the 103Pd-treated patients.
Conclusion: Despite the different management recommendations that evolved during the study
period, the clinical outcome for patients treated with either radionuclide were similar
with respect to bio- chemical disease-free sur vival. Although specific d osimetric
comparisons are not valid given differences in imaging over the study course, the
complication rate appears to be somewhat higher for 125I, which is consistent
with a radiobiologic model. |
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