8-cyberknife-trials - Royal Marsden Hospital

The Royal MarsdenPresentation today– Cyberknife introduction– Proposed trial for oligometastases– Other trials we are hoping to run

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The Royal MarsdenHow do we usually deliver radiotherapy?– 2-4 beams

The Royal MarsdenWhat is the problem?– A large amount of normal tissue gets a high dose ofradiotherapy (unwanted)

The Royal MarsdenHow do we usually deliver radiotherapy?– Line up to skin tattoos

The Royal MarsdenWhat is the problem?– Tumours ( and normal organs around them) moveduring radiotherapy and from day to day.

The Royal MarsdenWhat is Cyberknife?– Radiotherapy – no knives!– Normal radiotherapy machine but mounted on arobot– Delivers very small amounts of radiotherapy frommany different directions– Moves with the tumour

The Royal MarsdenX-ray SourcesIMAGINGSYSTEMLinearAcceleratorROBOTICDELIVERYSYSTEMTARGETING SOFTWAREIRISManipulatorImageDetectors

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The Royal MarsdenHow does Cyberknife track the tumour?– Skull tracking – uses the bony contour of the skull toadjust for small movements– Used for tumours inside the head

The Royal MarsdenHow does Cyberknife track the tumour? – spinetracking

The Royal MarsdenHow does Cyberknife track the tumour? – fiducialtracking

The Royal MarsdenHow does Cyberknife track the tumour? - lung

The Royal MarsdenWhat about breathing? - Synchrony

The Royal MarsdenWhat else is different about Cyberknife?– Fewer treatments ( 1-5 fractions)– E.g. conventional prostate radiotherapy:Normal radiotherapy 37 daily treatmentsCyberknife 5 treatments– Can deliver “radioablative doses” – destroy all tissuethat is targetted

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The Royal MarsdenSounds too good to be true?– Treatment times much longer 35 mins – 2 hours forcomplicated synchrony cases– Lack of long term efficacy data, despite use in theUSA for >8 years

The Royal MarsdenOligometastasis trial– Before cancer metastasizes (spreads) we know we cancure– After cancer metastasizes, we aim to control cancerbut cannot usually cure– Is there a subset of patients where the cancer has onlyspread to 1-2 areas, where we still have theopportunity to cure?

The Royal MarsdenWhat do we know already?– Liver metastases from colorectal cancer – long termsurvivors after resection– Lymph node metastases from breast cancer – stillpotentially curable– Lung metastases from sarcoma

The Royal MarsdenOligometastases trial– 50 patients initially for a pilot study– Variety of tumour types– 1-3 sites of metastases– No other treatment that we know will cure

The Royal MarsdenTrial designPatients with1-3 metastasesRandomise15 Gy in 3 fractions 45 Gy in 3 fractions

The Royal MarsdenOutcomes– Initial pilot study will establish feasibility of this trialdesign in 50 patients- will they accept randomisation?– How do they tolerate the treatment?– What parameters should be stipulated if this proceedsto a larger multicentre trial? Eg maximum size ofmetastasis, do some sites do worse?

The Royal MarsdenUltimate aim– Larger trial, incorporating all UK NHS Cyberknifecentres (currently 3) to look at cause-specificsurvival– i.e. do less patients die of their cancer after high doseCyberknife radiotherapy?– Potentially could extend to other types of focussed(stereotactic) radiotherapy on machines other thanCyberknife

The Royal MarsdenQuestions for you– One other proposal is to randomise betweenCyberknife high dose radiotherapy and Noradiotherapy at all (as these patients would notusually get any radiotherapy) – do you think patientswould accept this?

The Royal MarsdenTrial design?Patients with1-3 metastasesRandomiseStandard of carei.e no treatment45 Gy in 3 fractions

The Royal MarsdenOther trials– Low/Intermediate risk prostate cancer: randomisingto surgery/Cyberknife and Cyberknife/conventionalradiotherapy– Prostate boost study – looking at just concentratingradiotherapy on the area of tumour rather than thewhole gland– Liver metastases from colorectal cancer: treating with45 Gy in 3 fractions

The Royal MarsdenA note of caution– New technology brings new possibilities both tosucceed and to fail.