Home Radiation Focal ultrasound may offer an alternative to radiation therapy and surgery for intermediate-risk prostate cancer

Focal ultrasound may offer an alternative to radiation therapy and surgery for intermediate-risk prostate cancer

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medwireNews: Magnetic Resonance Imaging (MRI)-Guided Focal Ultrasound Therapy Is A Feasible Treatment For Grade 2-3 Prostate Cancer, Say Phase 2b Trial Results Published In The Lancet Oncology.

“These results support focal therapy for selected patients and its use in controlled trials to determine whether a tissue-sparing approach is effective in delaying or eliminating the need for long-term radical whole-gland therapy,” says Behfar. Ehdaie (Memorial Sloan Kettering Cancer Center, New York, USA) and co-authors.

The study recruited men aged at least 50 years with unilateral prostate adenocarcinoma, visible on MRI and at intermediate risk. This was defined as a prostate-specific antigen (PSA) level of 20 ng/mL or less, disease group grade 2 or 3, and tumor staging of T2 or less.

A total of 101 men with an average age of 63 years and a median PSA of 5.7 ng/mL received focused ultrasound energy titrated to reach a temperature of 60 to 70°C for tissue ablation of their index lesion and an expected margin of at least 5 mm, explain the investigators.

At 6 months, 95% of patients were free of stage 2 or more advanced disease on targeted, systematic MRI biopsy of the treated area of ​​their prostate, as were 88% of the 89 patients who underwent biopsy after 24 month.

“Our results met the originally predefined efficacy criteria,” report Ehdaie et al.

Of the 11 men who had grade 2 group disease or worse in the treatment site at 24 months, two had grade 3 group, one had grade 4 group, and two had grade 5 group disease.

The researchers also used the combined prostate biopsy protocol to look for disease throughout the gland. At 6 months, 76% of the 101 men were free of grade 2 disease or worse, as were 60% of the 98 patients assessed at 24 months.

The team notes that 19% of men had grade 2 or more severe prostate cancer outside of the treatment area at the 6-month biopsy, but suggests that “[g]Given the short interval between biopsies, rather than representing new cancer sites, these men were most likely harboring these additional cancers not detected prior to treatment.

Analysis shows that PSA levels decreased after focal ultrasound, stabilized at around 6 months, and increased again after 24 months.

Compared to baseline, 24 months after treatment, patients had “slightly worse” scores for erectile function, sexual satisfaction and overall satisfaction.

The International Prostate Symptom Score measures of lower urinary tract symptoms and quality of life were “similar” at both time points, with none of the 18 patients who had Group 2 or less severe incontinence requiring a pad.

“These functional outcomes compare very favorably to patient-reported outcomes after whole-gland treatments, such as radical prostatectomy and radiation therapy, which, while effective, are associated with substantial and persistent side effects that have a impact on quality of life,” write Ehdaie et al. .

There was one procedure-related grade 3 adverse event (AE) (urinary tract infection), and grade 2 or less severe hematuria and urinary retention occurred in 24% and 15% of patients, respectively. There were no serious treatment-related AEs, according to the investigators.

The team acknowledges that the 24-month biopsy alone “is not a sufficient surrogate endpoint for metastasis or cancer-specific death” and that without a comparative treatment arm “we cannot estimate the long-term clinical benefit term of treatment for these men rather than following an active surveillance protocol.

Nevertheless, the authors point out that “most” of the men in their study would otherwise have undergone radiation therapy or surgery, but only 15% continued to have Group 3 disease or more severe during the follow-up period.

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Lancet Oncol 2022; doi: 10.1016/S1470-2045(22)00251-0