Brachytherapy Results for Low- and Intermediate-risk Prostate Cancer Treated at Mayo Clinic

According to a retrospective study published this month in the journal Brachytherapy,  permanent low-dose-rate (LDR)  prostate brachytherapy monotherapy with I-125 has worked well for men with low-and intermediate-risk prostate cancer.

Investigating outcomes for a series of 974 patients treated at the Mayo with this type of permanent “seed” implant brachytherapy  analysts focused on factors associated with biochemical failure and survival.

They write: “Consecutive patients undergoing LDR with I-125 at our institution between 1998 through 2013 for primary intact prostate cancer were examined. Those with low- and intermediate-risk disease receiving LDR with a minimum of 2 years followup and at least one post-LDR prostate-specific antigen (PSA) were included.”

“About 974 patients satisfied inclusion criteria,” the Mayo summary goes on. “With median followup of 72 months [i.e. six years], biochemical failure occurred in 45 patients. Freedom from biochemical failure as defined by the Phoenix criterion was 96% and 88% at 5 and 10 years, worse for intermediate risk as compared with low risk, with 10-year freedom from biochemical failure of 76% versus 92% . . . respectively.”

Looking at various factors that may affect outcomes, the Mayo’s analysts zoned in on “increased prebiopsy PSA, Gleason 4 + 3, and no androgen deprivation therapy.” These factors were “associated with biochemical failure.”

“Gleason 4 + 3 was the factor most strongly associated with biochemical failure . . . No examined factors were associated with local failure. Gleason 4 + 3 disease increased the likelihood of distant metastasis . . . and prostate cancer–specific death . . . . No difference in outcomes between patients with Gleason 3 + 3 versus 3 + 4 was observed.”

Conclusions

“LDR brachytherapy provided excellent outcomes in this large series of patients treated for localized organ-confined prostate cancer. Local recurrence at 10 years was low at 2.1%.”

“Primary Gleason 4 + 3, higher pretreatment PSA, and no receipt of androgen deprivation therapy were the only factors associated with biochemical failure. Primary Gleason 4 disease was also predictive of distant metastases and decreased prostate cancer–specific survival.”

Published online in Brachytherapy, October 4 2018: Permanent prostate brachytherapy monotherapy with I-125 for low- and intermediate-risk prostate cancer: Outcomes in 974 patients.

Lead author of the study, Brian J. Davis MD PhD, treats prostate cancer at Mayo with

  • External beam radiotherapy
  • Protons
  • Brachytherapy

edited by J Strax for PSA Rising October 10 2018.