High-dose-rate brachytherapy for poor-prognosis, high-grade glioma: (phase II) preliminary results

The purpose of this study was to investigate the palliative effectiveness of an interstitial fractionated high-dose-rate (HDR) brachytherapy regimen in patients with poor-prognosis, high-grade glioma.

An after-remote-loading microSelectron HDR lr-192 370 GBq unit was used. A unique coaxial after-loading catheter was stereotactically inserted through the center of the target volume. The treatment schedule was: 5 fractions, 5 Gy per fraction, or alternatively 7 fractions, 3.85 Gy per fraction, at the dose specification surface, 2 fractions per day. Twenty-four patients have been treated: in 17 of them (T1 G3-4) the catheter was implanted during stereotactic biopsy procedure; in the other 7 cases (T2 G3-4), subjected to partial resection and reduced to yT1, the catheter was implanted following surgery with a mean delay of 15 days.

The treatment was feasible and well tolerated. The complete course takes no more than 7 days. The acute complication rate (2/24) seems to be acceptable. The median survival was 8 months. No less than 45% of the patients had a WHO grade 2 score or better at any time of follow-up. At 4 months of follow-up, functional status, assessed using a verbally administered Barthel index, had improved from the pretreatment level in 29.1% of the 18 surviving patients and remained stable in another 22.2%. A minimal response or stable disease, according to CT scan, was obtained in about half of the assessable survivors at any time of follow-up.

The short course of brachytherapy provides a good palliation in terms of functional improvement in a high proportion of patients, with low and acceptable toxicity.