Ketogenic Diets as an Adjuvant Therapy in Glioblastoma

A prospective, non-blinded, randomized, pilot study will be undertaken in patients with glioblastoma (GB). Patients will be randomized to the modified ketogenic diet (MKD) or the medium chain triglyceride ketogenic diet (MCT) for a 12 week period (primary completion). If patients wish to remain on diet, they will be offered dietetic support for a total of 12 months (secondary completion).

The trial will be open to all Walton Centre Foundation Trust patients with a newly diagnosed GB, who have undergone surgical resection or biopsy within the last four months and who are going on to receive/ are currently receiving/ have completed oncological treatments (radiotherapy or chemotherapy or chemoradiotherapy). Patients will be referred via neuro-oncology multi-disciplinary meetings and neurosurgical clinics, post histology. The diet will be offered alongside standard care, commencing within four months of surgery.

Both diets are high in fat and low in carbohydrate, but contain different types and amounts of fats. The MKD is 80% fat (predominately long chain fatty acids) and 5% carbohydrate, whilst the MCT diet is 75% fat (30% of which is medium chain fatty acids) and 10% carbohydrate.

A permuted block randomization method will be adopted, using 'sealedenvelope' randomization system. This will be set up and administered by the statistician, who is not involved with the recruiting of patients.

Patients will receive regular input from the trial dietitian. This includes clinical consultations at baseline, dietary initiation, week 6, week 12 and every 3 months thereafter and telephone consultations at weeks 1, 3 and 9. Patients will receive dietary and ketone monitoring education.

Assessments and monitoring undertaken at each consultation include anthropometry, biochemistry, compliance, tolerance, acceptability, quality of life and ketosis.

Informed consent will be obtained prior to enrollment and the patient may withdraw at any time.

An information study is also embedded into KEATING, to aid understanding of the patients' recruitment experience and viewpoints, by interviewing a sub-sample of patients and their relatives/ carers. This will enable the design of bespoke strategies to optimise recruitment to future trials related to ketogenic diets and gliomas

Inclusion criteria

• Age ≥16 years
• Patient at The Walton Centre NHS Foundation Trust
• Performance status ≤2
• Confirmed histological diagnosis of glioblastoma
• Undergone surgical resection or biopsy and will go onto receive/ is receiving/ has received oncological treatments

Exclusion criteria

• Having prior use of KD
• Kidney dysfunction
• Liver dysfunction
• Gall bladder dysfunction
• Metabolic disorder
• Eating disorder
• Diabetes (requiring medication)
• Body mass index ≤ 18.5kg/m2
• Weight loss medications
• Currently pregnant or breast feeding
• Performance status ≥3