Random variation in rectal position during radiotherapy for prostate cancer is two to three times greater than that predicted from prostate motion
Linking radiation dose at the voxel level with toxicity

The VoxTox Research Programme, funded by Cancer Research UK, focuses on reducing toxicity from radiotherapy (RT). This will have benefits for patients and society. Additionally, individualised reduction of toxicity risk will allow dose escalation, and combination with chemotherapy. Since a strong radiotherapy dose-response relationship exists for many tumours, this will improve cancer cure rates.


To quantify the differences between planned dose and the dose actually delivered during the whole course of radiotherapy, and to link these data to differences between expected and observed toxicity. To determine the relative contributions to individual variation in toxicity from underlying biological factors or physical dose variation. Develop a suite of integrated software tools for dose review during the treatment course, with the objective of individualising treatment, based on predicted toxicity.


We will analyse the discrepancy between RT doses which are planned, and those actually delivered, based on daily CT data acquired within our clinical programme of high precision image-guided radiotherapy. In Cambridge we have a unique archive of daily volumetric imaging of patients treated on our TomoTherapy units. We will develop systems to map the location of each point (voxel) within the patient outline, and then to re-compute the dose at that point each day during treatment. We will apply techniques from image processing, materials modelling, tumour & tissue modelling and radiation biology to construct models of cumulative dose during treatment that cannot be achieved using current techniques. To do this we will bring together a cross-disciplinary group of clinicians and clinically-orientated scientists from the University of Cambridge Department of Oncology, the NHS Oncology Centre, the University of Cambridge Cavendish Laboratory, the University of Cambridge Engineering Department and the CR UK Cambridge Research Institute.

How will the results be used?

The results will be used to improve radiotherapy based on individualised toxicity. More accurate data on the relative contributions to individual variation from underlying biological factors or physical dose variation will feed in to studies of genetic determinants of individual variation in toxicity (radiogenomics). The development of an integrated suite of software tools for dose review during the treatment course will allow individual toxicity prediction and provide capability to re-plan treatment including toxicity as an optimisation parameter. Together, these tools will allow individualised treatment with reduced toxicity. The core tools will be provided free for use by the radiotherapy community.

Clinical trials

Please refer to the clinical study participants page.

VoxTox people

Programme members

Voxtox is a unique interdisciplinary research programme with members collaborating from a range of different fields and organisations. These include the University of Cambridge departments of Oncology, Physics (Cavendish Laboratory), Engineering, Medicine, and Applied Mathematical and Theoretical Physics in the University of Cambridge; colleagues from Addenbrooke's Hospital in Cambridge in Radiotherapy Physics, Cambridge Cancer Trials Centre , Cambridge Clinical Trials Unit , a colleague from the University of Manchester, and the CRUK-Cambridge Institute.

Chief and Principal Investigator and Chair of VoxTox Programme Board Professor Neil Burnet, University of Cambridge Department of Oncology, Addenbrooke's Hospital

Programme Board

  •  Professor Andy Parker, High Energy Physics, Cavendish Laboratory
  •  Dr Charlotte Coles, Oncology Centre, Addenbrooke's Hospital
  •  Dr Michael Sutcliffe, University of Cambridge Department of Engineering
  •  Dr Raj Jena, Oncology Centre, Addenbrooke's Hospital
  •  Dr Richard Benson, Oncology Centre, Addenbrooke's Hospital
  •  Dr Simon Russell Oncology Centre, Addenbrooke's Hospital
  •  Professor Simon Tavaré CRUK- Cambridge Institute and DAMTP, University of Cambridge
  •  Dr Simon Thomas,Radiotherapy Physics, Addenbrooke's Hospital
  •  Dr Mark Gurnell, University of Cambridge Department of Medicine 
  •  Michael Simmons, Cavendish Laboratory (Programme Co-ordinator)

Other Co-investigators 

  • Dr Simon Bond, Co-I, Senior Statistician, Cambridge Clinical Trials Unity
  • Dr Michael Williams Co-I, Consultant Clinical Oncologist, Oncology Centre, Addenbrooke's Hospital
  • Dr Andrew Hoole, Co-I
  • Dr Gill Barnett, Co-I Clinical Research Fellow, Oncology Centre, Addenbrooke's Hospital


  • Karl Harrison, Research Associate, Cavendish Laboratory
  • Dr Marina Romanchikova, Computer Scientist, Radiotherapy Physics, Addenbrooke's Hospital
  • Leila Shelley, PhD student, Department of Engineering, University of Cambridge
  • Dr David Noble, Clinical Research Fellow, Department of Oncology, University of Cambridge
  • Dr Jessica Scaife, Clinical Research Fellow & Honorary Specialty Registrar in Clinical Oncology, Department of Oncology, University of Cambridge
  • Amy Bates, Research Radiographer, Cambridge Cancer Trials Centre, Addenbrooke's Hospital

Visiting students

  • Nina Niebuhr, University of Hedielberg
  • Mariana Silva, University of Lisbon

Other Programme collaborators 

  • Dr Yvonne Rimmer
  • Dr Sarah Jefferies
  • Dr Gail Horan
  • Dr Susie Harden
  • Sam Tudor, Clinical Radiotherapy Physicist, Addebrooke's Hospital
  • Professor Catharine West , University of Manchester
  • Dr Alison Dunning
  • Mark Hayes, Director of eScience, Centre for Scientific Computing, Cavendish Laboratory
  • Dr Hannah Chantler, Clinical Radiotherapy Physicist
  • Sue Bailey, Senior Clinical Nurse, Cambridge Cancer Trials Centre, Addenbrooke's Hospital
  • Kath Walker, Head of Radiotherapy, Addenbrooke's Hospital
  • Dr Sridevi Nagarajan, Senior Data Manager, Cambridge Clinical Trials Unit, Addenbrooke's Hospital

The VoxTox Research Programme is funded by