A2: Failure pattern and survival after carmustine implants and concurrent chemo-radiation with temozolamide in newly diagnosed glioblastoma patients
1The Cancer Centre, Royal Stoke University Hospital, University Hospitals of North Midlands NHS Trust, Stoke-on-Trent, UK
In the UK, since the publication of National Institute for Health and Care Excellence (NICE) guidelines (2007), there has been an increase in the usage of carmustine implants after maximal (>90%) safe resection in patients with newly diagnosed glioblastoma (WHO grade IV glioma) (1). Concurrent chemo-radiotherapy (CRT) with synchronous and adjuvant temozolamide is currently the standard of care for good performance status patients (2). There is published retrospective evidence that most relapses occur locally after radical CRT treatment failure (3,4). However, there is little evidence to suggest the pattern of relapse after surgery with insertion of carmustine implants and adjuvant CRT. The aim of this retrospective study was to investigate the failure patterns and survival in newly diagnosed glioblastoma patients treated with triple modality treatment i.e. maximal safe resection, Carmustine implants, concurrent CRT with temozolamide.
Between 2009 and 2014, 25 patients with newly diagnosed glioblastoma treated with triple modality therapy were identified from the radiotherapy electronic database. We evaluated the local recurrence rate, time for recurrence, overall-survival (OS) and progression-free survival (PFS) from day of surgery. Imaging from relapse was then fused with the radiotherapy treatment volumes analyzing the relapse patterns within the planning target volume (PTV) 95% iso-dose line.
The median age of the patients was 57 years (range 42-69), male : female ratio being 1:1.3. After a median follow up of 48 months (range 12-70), twenty patients (80%) have died. Of these, 15 patients (60%) had local relapse and died of progressive disease, the remaining 5 patients (20%) had no relapse and died of other causes. From the five patients who are alive, 4 had no recurrence and 1 patient is alive with local recurrence. In total, 16 patients (64%) had recurrence and the pattern of relapse was with in 2cm of the original PTV 95% iso-dose line. The median PFS was 12 months (95% confidence interval [CI] 0.26-0.66) and OS was 15 months (95% CI 0.28-0.69) respectively.
Local failure within 2cm of the PTV 95% isodose line appears to be the predominant pattern of relapse in all these patients who had insertion of carmustine implants and CRT with temozolamide. Future prospective randomized studies will be vital to establish this.