HIFU has been a common primary prostate cancer treatment in Europe for quite a while. Currently, in the United States, there are a number of clinical trial sites evaluating HIFU as a primary treatment. Like all other primary treatments there is a significant failure rate causing men to move on to salvage therapy.

In Europe it isn’t uncommon for men who have failed HIFU treatment to undergo another course of HIFU as a salvage therapy.

At the Hôpital Universitaire Pellegrin, Bordeaux, researchers decided to evaluate an alternative, salvage radiotherapy (SRT) as a treatment following HIFU failure for localized prostate cancer.

From March 1995 to March 2008, all men who presented with histological proven persistent local disease following HIFU were treated with curative intent by salvage radiotherapy (with or without hormonal treatment). This study was a single-center retrospective study.

• All the men were given conformal radiotherapy with a median dose of 72 Gy (65-78 Gy).

• The primary outcome measure was progression-free survival (PFS), which was defined as no biochemical relapse (three consecutive rises in prostate-specific antigen

[PSA] with a velocity >0.4ng/ml per year or PSA >1.5ng/ml) and no additional treatment.

• The researchers also evaluated the predictive factors of failure by using univariate and multivariate analysis.

• Adverse events in terms of urinary and digestive toxicity, urine incontinence, and erectile dysfunction (ED) were reported.

The median (range) and mean (standard deviation) follow-up of the 100 men analyzed was 33 months (5-164 mo) and 37.2 months (23.6 mo), respectively.

• Eighty-three men received SRT alone, and 17 received SRT and androgen-deprivation therapy.

• For the 83 men treated solely with radiation therapy, PFS was 72.5% at 5 yr and 93%, 67%, and 55% for the low-, intermediate-, and high-risk groups, respectively.

• In the univariate analysis, PSA level prior to SRT, risk status, PSA nadir after SRT, PSA nadir after SRT >0.2ng/ml, and time to achieve this nadir were all predictive of failure.

• In the multivariate analysis, PSA nadir post-SRT with a threshold at 0.2ng/ml and time to achieve this nadir were the significant predictive factors of failure.

• Gastrointestinal toxicity was low; urinary toxicity grade SRT provides satisfactory oncologic control after HIFU failure with little (or mild) additional toxicity.

These results indicate that SRT after failed HIFU might be an acceptable means of salvage therapy. SRT warrants further investigation in this situation.

Reference: Eur Urol. 2010 Jun 11. Epub ahead of print.
doi: 10.1016/j.eururo.2010.06.003; Riviere J, Bernhard JC, Robert G, Wallerand H, Deti E, Maurice-Tison S, Ardiet JM, Maire JP, Richaud P, Ferriere JM, Ballanger P, Gelet A, Pasticier G.

PubMed Abstract
PMID: 20598436

Joel T Nowak, M.A., M.S.W.