Ralph Miller, MD, on the state of HIFU in prostate cancer

In this interview, Ralph J. Miller Jr, MD, discusses the current state of focal therapy, specifically high intensity focused ultrasound (HIFU), in the treatment of patients with prostate cancer. Miller is a urologist at Allegheny Health Network in Pittsburgh, Pennsylvania.

This transcript was AI generated and edited by human editors for clarity.

Ralph J. Miller Jr, MD

What are some of the advantages of HIFU?

The advantages that HIFU has seem to be to a large part from the patient perspective. In urology, over the past few decades, we've developed a number of treatments that are very effective at treating and even curing prostate cancer, but those treatments have some significant long-term [adverse events]. As time has gone on and patients have increased in sophistication, patients in general are asking for treatments that don't have long-term negative impacts on their urinary function and their sexual function. So, I think the advantage of HIFU from the patient perspective is that it's a treatment that can be performed with minimal effect on potency and minimal effect on urinary function.

Which patients are best suited for this approach?

HIFU is currently being used in a barrage of patients around the country. I think the best candidates, and certainly the ones at our program, are patients who fall into a category of intermediate-risk prostate cancer. We like to treat patients with either unilateral disease or disease that's specifically confined to an index lesion, as seen on a prostate MRI. [There are] a number of other lesser qualifications, but those are the main ones: intermediate-risk, localized, probably unilateral prostate cancers.

What is the current state of data surrounding this procedure?

There has been lots published about HIFU, going back at least to the 1990s. Most of the published data about HIFU tended to be with relatively short-term follow-up. We know from the long-term radical prostatectomy data that it can take 10 to 15 years, or even longer, to tell the ultimate effectiveness of a treatment for prostate cancer. For HIFU, one of the best recent studies published was a study from France, published in The Journal of Urology, and also presented at the May 2024 [American Urological Association] meeting in San Antonio, [Texas]. This was a study of about 3300 men in France who were randomized to either radical prostatectomy or HIFU. After an average of 30 months of follow-up, HIFU had non-inferiority, with the end point being the need for salvage therapy.

Are you aware of any ongoing research or clinical trials that are exploring the efficacy of this approach?

Of course, once you have a large database of patients with HIFU and other treatments, the database can be queried in years in the future and simply see how the treatments pan out. There's technical research going on in terms of the efficacy of tissue ablation, and there's research going on in terms of patient selection. There will also be the observation of long-term databases, which will tell us more about HIFU effectiveness in the long-term. We have to remember that HIFU just got a universal coverage decision in the US in about 2022, so if you start seeing large numbers of patients entered into databases at that time in the US, it will take a little while before you have the data that we already have for radiation and surgery.

What impact has imaging had on focal therapy?

Imaging has already had a very big impact on the field of focal therapy. For many years, the general rule was that if you're going to treat local prostate cancer, that you must treat the entire prostate. Part of the reason for that was that we weren't very good at telling where the cancer is and where it isn't. As we've had more use of prostate MRI and more use of rigorously mapped biopsies, we're starting to get a better idea of where prostate cancer is and where it isn't in the prostate.

Of course, that information is never perfect. I will say, though, that part of this is the developing concept in the treatment of prostate cancer of the index lesion. The idea there is that there is a main focus of cancer. These days, we determine that by the volume of cancer and by the grade of cancer. We feel that treating the index lesion will have a beneficial effect. There may even be areas of cancer outside the index lesion that is grade group 1, and normally those areas would be treated with observation. So, in using focal HIFU, you might have an instance where you're treating an index lesion, and you're aware of other smaller or lower grade amounts of cancer within the prostate, and you're just going to observe those.

Is there anything else that you wanted to add?

[HIFU is] certainly very popular with patients who have individually gone and looked at treatments in their own research. I do think we need to be cautious that we not over apply HIFU moving forward.