BACKGROUND AND PURPOSE: The impact of weight loss and anatomical change during head and neck (H&N) radiotherapy on spinal cord dosimetry is poorly understood, limiting evidence-based adaptive management strategies. MATERIALS AND METHODS: 133 H&N patients treated with daily mega-voltage CT image-guidance (MVCT-IG) on TomoTherapy, were selected. Elastix software was used to deform planning scan SC contours to MVCT-IG scans, and accumulate dose. Planned (DP) and delivered (DA) spinal cord D2% (SCD2%) were compared. Univariate relationships between neck irradiation strategy (unilateral vs bilateral), T-stage, N-stage, weight loss, and changes in lateral separation (LND) and CT slice surface area (SSA) at C1 and the superior thyroid notch (TN), and ΔSCD2% [(DA - DP) D2%] were examined. RESULTS: The mean value for (DA - DP) D2% was -0.07 Gy (95%CI -0.28 to 0.14, range -5.7 Gy to 3.8 Gy), and the mean absolute difference between DP and DA (independent of difference direction) was 0.9 Gy (95%CI 0.76-1.04 Gy). Neck treatment strategy (p = 0.39) and T-stage (p = 0.56) did not affect ΔSCD2%. Borderline significance (p = 0.09) was seen for higher N-stage (N2-3) and higher ΔSCD2%. Mean reductions in anatomical metrics were substantial: weight loss 6.8 kg; C1LND 12.9 mm; C1SSA 12.1 cm2; TNLND 5.3 mm; TNSSA 11.2 cm2, but no relationship between weight loss or anatomical change and ΔSCD2% was observed (all r2 < 0.1). CONCLUSIONS: Differences between delivered and planned spinal cord D2% are small in patients treated with daily IG. Even patients experiencing substantial weight loss or anatomical change during treatment do not require adaptive replanning for spinal cord safety. ; - The VoxTox project received a 5-year programme grant from Cancer Research UK (CRUK) (Ref: C8857/A13405). - KH, MR and AMB were supported by the programme grant. - DJN is supported by a CRUK Clinical Research Fellowship (Ref: C20/A20917). - PLY and SYKS were supported by the Singapore Government. - LEAS is supported by the University of Cambridge W D Armstrong Trust Fund. - NGB was supported by the NIHR Cambridge Biomedical Research Centre.
In: Kurian , K , Jenkinson , M D , Brennan , P , Grant , R , Jefferies , S , Rooney , A G , Bulbeck , H , Erridge , S C , Mills , S , McBain , C , McCabe , M G , Price , S J , Marino , S , Moyes , E , Qian , W , Waldman , A , Vaqas , B , Keatley , D , Burchill , P & Watts , C 2017 , ' Brain tumor research in the United Kingdom: current perspective and future challenges : A strategy document from the NCRI brain tumor CSG ' , Neuro-Oncology Practice . https://doi.org/10.1093/nop/npx022
The National Cancer Research Institute (NCRI) is a partnership of charity and government research funders whose purpose is to improve health and quality of life by accelerating progress in cancer-related research through collaboration. Under this umbrella, the NCRI Brain Tumor Clinical Studies Group is focused on improving clinical outcomes for adult patients with brain and central nervous system tumors, including those with brain metastasis from other primary sites. This document discusses the current state of clinical brain tumor research in the UK and the challenges to increasing study and trial opportunities for patients. The clinical research priorities are defined along with a strategy to strengthen the existing brain tumor research network, improve access to tissue and imaging and to develop the future leadership for brain tumor research in the UK. This strategy document may serve as a framework for other organizations and countries.