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Long-Term Outcomes after Treatment with External Beam Radiation Therapy and
Palladium-103 for Patients with Higher Risk Prostate Carcinoma, Michael
Dattoli, MD, Kent Wallner, MD, Lawrence True, MD, Jennifer Cash, MS, and
Richard Sorace, MD, PhD. Cancer, 2003;97(4):979-983.
| Type of Study |
Examined long-term outcomes for higher risk prostate cancer
patients following a combined treatment with external beam radiation therapy
and brachytherapy with palladium-103(using the TheraSeed® device). |
| Purpose |
To determine the significance of prostatic acid phosphatase (PAP)
levels in patients with higher risk, early-stage prostate cancer. |
| Issue |
How effective is brachytherapy?
|
| Number of Patients |
161 |
| Type of Patients |
| • |
Stage T1-T3 prostate carcinoma (according to the 1992 American Joint Committee
on Cancer criteria). |
| • |
Gleason score equal to or greater than 7. |
| • |
PSA level greater than 10. |
| • |
All patients received external beam radiation therapy, followed four weeks
later by brachytherapy with palladium-103. |
|
| Length of Time
Patients Were Followed |
118 of the patients were followed more than five years. |
| Notes |
Freedom from biochemical failure was defined as a serum PSA level
less than or equal to 0.2 ng/mL at last follow-up. |
| Results and/or
Conclusions |
| • |
Statistical projections indicated a cure rate of 79% after 10 years. |
| • |
“The biochemical cure rate was remarkably high among the 161 patients
evaluated.” |
| • |
“…PAP was the strongest predictor of long-term biochemical failure…” |
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Researchers studied the long-term outcome of 161 higher risk prostate cancer
patients treated with a combination of brachytherapy using palladium-103 (using
the TheraSeed® device) and external beam radiation therapy. Each
patient had a Gleason score of 7 or more and/or a PSA level greater than 10.
Patients received external beam radiation therapy followed four weeks later by
brachytherapy with palladium-103.
“The biochemical cure rate was remarkably high among the 161 patients
evaluated,” the researchers concluded. Actuarial analysis indicated 79% of
patients are disease-free 10 years after treatment. “We are encouraged that
aggressive, brachytherapy-based treatment seems to provide long-lasting
biochemical disease control, even in patients with PSA levels greater than 20…
Although longer follow-up is needed, the apparent plateau on the freedom from
failure curve suggests that malignant prostate tumors have been eradicated
rather than simply suppressed.”
The objective of the study was to address the significance of prostatic acid
phosphatase (PAP) levels in predicting the return of prostate cancer following
treatment of patients diagnosed with higher risk, early-stage disease. Prior to
the discovery of prostate specific antigen (PSA), PAP levels were the principal
factor used to measure the presence of prostate cancer in patients. Because of
PSA’s greater sensitivity for detecting disease and monitoring residual
prostate carcinoma, it replaced PAP measurements in the early 1990s as the
principal biochemical parameter. However, recent studies indicate PAP
measurements may be helpful in predicting the return of cancer. High PAP levels
before treatment may indicate micrometastatic disease. According to the study,
“The presence of an elevated PAP level was the strongest predictor of
biochemical failure.” The researchers concluded it may be beneficial to
reintroduce PAP measurements in patients who demonstrate PSA levels between 10
and 20 before treatment. Those with elevated pre-treatment PAP levels may be
candidates for more aggressive radiation treatment.
Principal Investigator: Michael Dattoli, M.D., Dattoli Cancer Center and Brachytherapy
Research Institute, Sarasota, Fla.
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