High-dose proton therapy and tomotherapy for the treatment of sacral chordoma: a retrospective monocentric study.

OBJECTIVE: Radiation therapy (RT) is used for the treatment of sacral chordoma, in combination with surgery or alone for unresected tumours, to improve local control (LC) and potentially overall survival (OS). The purpose of the present study was to evaluate efficacy and toxicity of proton therapy (PT), and/or intensity modulated radiation therapy (IMRT), particularly Tomotherapy, for sacral chordoma treatment. Material: Between November 2005 and June 2018, 41 consecutive patients who were not included in clinical trials, received sacral chordoma radiation treatment in Institut Curie with Tomotherapy alone in 13 patients, and combined PT and Tomotherapy boost (Proton - Tomo) in 28 patients. RT was delivered as the exclusive local treatment in 11 patients, and as a post-operative complementary treatment in 30 patients. RESULTS: After a median follow-up of 46 months (range, 0-125 months), eight local relapses were observed, and seven patients developed distant metastasis (particularly bone and lung). The 2- and 5- year local relapse rates were 11.4% CI (0.65-22.2%) and 29% (10.5-47.4%), respectively. Over the follow-up period, ten patients died (24.4%). The estimated 2- and 5-year OS rates were 91.4% CI (82.5-100%) and 74.5% (59.4-93.5%), respectively. Fibrosis, cauda equina syndrome, and pain were the most common late toxicities. The comparison between Tomotherapy alone and Proton - Tomo revealed that acute and late cystitis were significantly more frequent in the Tomotherapy group: SHR = 0.12 IC95% (0.01-0.90 [p = .04]), as well as late proctitis. A dosimetric comparison confirmed the interest of PT to spare rectum and bladder in this context. CONCLUSION: RT remains essential to improve local control in sacral chordoma. The combination of proton and photon seems to improve organ at risk sparing, resulting in a decreased rate of reported late toxicities.

Performance of an interstitial glucose monitoring device in patients with type 1 diabetes during haemodialysis.

Background: The use of interstitial glucose monitoring devices such as flash glucose monitoring has been shown to be beneficial in patients with type 1 diabetes mellitus (T1DM). However, these devices have been little studied in patients with diabetes treated by chronic haemodialysis (HD). Methods: The goal of this prospective, observational, multicentric study was to evaluate the analytical performance of the FreeStyle Libre 2 (FSL2) sensor in T1DM patients during HD sessions. During three HD sessions, interstitial fluid glucose (ISFG) concentrations given by the FSL2 were compared every 15 minutes with blood glucose (BG) concentrations obtained simultaneously. BG concentrations were measured by two different glucometers: the Accu-Chek Guide and StatStrip meters. Results: Twelve HD patients were included, with a mean age of 54 ± 11 years and a mean diabetes duration of 36.5 ± 11.6 years. Dialysis vintage was 35 ± 22 months. A total of 565 pairs of ISFG/BG values were available for analysis. The mean absolute relative difference, defined as the mean of the absolute relative differences between the ISFG and BG measurements, was 17.4% and 20.9% when the ISFG was compared with the StatStrip meter or Accu-Chek Guide, respectively. Interstitial results tend to underestimate blood results, but all values were classified as having clinically acceptable error. The differences observed remained stable during the dialysis session and were not associated with the ultrafiltration rate. Conclusion: Use of the FSL2 interstitial glucose monitoring device in HD patients with T1DM is clinically acceptable, even though the accuracy of the device is generally poorer than in studies including non-dialysis patients.