Clinical study participants

The picture shows the VoxTox Clinical Study Team, with one of the TomoTherapy machines which images and treats patients in the study. From left to right: Dr Raj Jena (Clinician Scientist & Consultant Clinical Oncologist), Mrs Amy Bates (VoxTox Research Radiographer), Prof Neil Burnet (Professor of Radiation Oncology and VoxTox Chief and Principal Investigator), and Dr Jessica Scaife (Clinical Research Fellow). Picture credit: Lex Ballantyne, Addenbrooke's Hospital Media Studio.

Title of clinical study

VoxTox: Linking Radiation dose at the Voxel level with Toxicity - Understanding about the side effects from radiotherapy in more detail


VoxTox - What are the detailed side effects (toxicity) after modern, targeted radiotherapy (RT) for head and neck cancer, prostate cancer and tumours in and around the brain, and can these be linked to the radiation dose received by the healthy tissues?

Since 2007, patients have been treated using image-guided intensity-modulated RT at Addenbrooke's Hospital in Cambridge. In preparing treatment, a Computed Tomography (CT) scan is used to create an individual RT plan, where the radiation beams are shaped to precisely treat the tumour, and avoid nearby healthy tissues (intensity-modulated RT). Each day before treatment, another CT scan ensures the patient is in the correct position (image-guided RT).

This RT is very precise but some of the treatment can still affect healthy tissues near the tumour, resulting in toxicity. This can result in lasting adverse effects on a person's health and well-being. Understanding more about the radiation dose being delivered to these healthy tissues, and about toxicity, could help us both to improve RT in order to reduce toxicity, and to give a higher RT dose to cancer cells, so curing more patients.

We will assess toxicity in patients already treated and those yet to be treated with this RT technique for up to 5 years after RT. The schedule for assessment depends on their tumour type, and whether they have been treated already. Assessments include interviews, quality of life questionnaires and blood tests to check hormone levels. We also want to adapt some of the daily positional CT scans, and to evaluate these and the RT plans in detail, in order to understand more about the radiation dose being delivered to the healthy tissues.

The study will run in Cambridge for 5 years after recruitment of the first patient and is funded by Cancer Research UK.


Start 03/2013 
End 03/2018

Who can participate

You may be able to enter this study if you

  • Are aged 18 or above
  • Have had a malignant or benign tumour of the head and neck, prostate or in or around the brain within the past 5 years
  • Have been or will be treated with daily image-guided RT on the TomoTherapy machines
  • Are well enough for the 5 year follow up schedule 

You cannot enter this study if you

  • Have already been treated with RT to the same area
  • Have been or will be treated with RT not using daily image guidance
  • Have been or will be treated on a machine other than the TomoTherapy machines

Main research question

The principal objective of the study is to understand in detail the side effects (toxicity) that patients experience after image-guided intensity-modulated radiotherapy (IGIMRT) to the head and neck, prostate and central nervous system. We will use interviews, questionnaires and blood tests to look at toxicity at regular intervals during and after treatment. This will allow us to understand how many patients develop side effects, and how long these side effects take to develop. In turn, this will allow us to reduce toxicity in the future.

Other research questions

There are 3 main secondary objectives:

  • To establish the best method for the daily positional CT scans. This will give the detail needed for the VoxTox Programme with the lowest risk and burden to both participants and the RT department. We will take into account the radiation dose to the patient, the length of time needed for scanning, and the images obtained.
  • To find out the doses of radiation that are actually delivered to the healthy tissues during a course of RT, and how different these are to the doses which were planned. For the first time, we will establish the doses being delivered to the salivary glands, the rectum and the hypothalamus and pituitary gland.
  • To find out whether toxicity is more closely related to the dose delivered to the healthy tissues, rather than the dose which we planned to give. We will compare the detailed toxicity information we gather with the toxicity that we were expecting based on the doses in the RT plan, and the information about RT toxicity from previous studies. We will look at whether this difference in toxicity is linked to differences between the doses actually delivered to the healthy tissues and those which we had planned to give.

Location of study


Further information and contact details

Please contact our research radiographer, Amy Bates, if you would like any further information about the study, or if you have any questions. 
Research radiographer: Amy Bates, Cambridge Cancer Trials Centre 
Working hours: 0830-1630 Monday to Friday 
Telephone Number: 01223 216083 

Chief Investigator: Professor Neil Burnet

VoxTox is funded by Cancer Research UK

These links may be of interest to participants and potential participants: