Good news

Great news for CyberKnife:

A new paper in the journal Radiation Oncology provides data on a series of 41 men treated with stereotactic body radiation therapy for intermediate-risk prostate cancer.

Ju et al. treated these 41 consecutive, intermediate-risk patients with 35 to 36.25 Gy in 5 fractions delivered using CyberKnife technology. All patients were assessed at baseline and followed-up for disease recurrence, PSA levels, toxicities, and quality of life (QOL).

Here are the results:

• 41/41 patients (100 percent) completed treatment
• The median follow-up was 21 months from treatment.
• The average (mean) PSA level for the 41 patients was
  • 7.67 ng/ml before treatment
  • 0.64 ng/ml after treatment
• 40/41 patients remained free from biochemical progression during the follow-up period
• No patients exhibited Grade 3 or 4 toxicities.
• Mean EPIC urinary irritation/obstruction and bowel QOL scores did decline post-treatment but subsequently returned to baseline.
• No significant change in sexual QOL was observed.

The authors conclude that, in this group of patients, an adequate radiation dose was delivered to areas of expected, microscopic, extracapsular extension in the majority of patients. They further state that, in their opinion, “the short-term PSA response, biochemical relapse-free survival rate, and QOL in this interim analysis are comparable to results reported for prostate brachytherapy or external beam radiotherapy.”

Clearly, we still need data from larger, longer-term studies to know if CyberKnife therapy is as good or better than other forms of radiation therapy in men with intermediate-risk disease. However, the present study does, at least, give us some degree of insight into what might reasoably be expected.