Tomotherapy Jill Matsuoka What is Tomotherapy • Tomo means “slice” in Greek. So tomotherapy is the slice by slice treatment of tumors • Combination of CT and IMRT technologies Types of Tomotherapy •2 Types of Tomotherapy -Serial Ganry of machine moves around the patient and treats 2 slices. Couch then moves in increments that are barely perceptible to the patient to treat the next 2 slices until dose is complete. (Curran, n.d) Types of Tomotherapy (FLROcenter.com) Types of Tomotherapy • Helical – Bore of the machine rotates around the patient while the table simultaneously moves through the machine History • 1994 - Corvus by the Nomos Corporation. First serial tomography machine. • 2002 – First patient treated with helical tomotherapy at University of Wisconsin. Developed by Thomas Mackie, professor at UW Madison. (Mackie, 2006) How does it work? •Older forms of treatment use larger beams with limited angles and without the ability to completely spare healthy tissue •Tomotherapy machines can deliver treatment with almost surgical precision CT imaging allows for precise contour of the tumor (City of Hope, n.d.) How does it work? • Tomotherapy uses hundreds of pencil beams that rotate 360° around the patient in a spiral pattern (City of Hope, n.d.) • One radiation beam can be divided into thousands of narrow, tiny beams called beamlets (Cancer Compass, n.d.) • The beamlets have varying intensity depending on whether they’re hitting the tumor or surrounding tissue (Cancer Compass, n.d.) How does it work? • These beamlets are possible through Intensity Modulated Radiation Therapy (IMRT) • IMRT is a dynamic treatment using a multileaf collimator 64 leaves, each 6.25 mm leaves move at 250 cm/second to open or shut in 20 milliseconds (Mayurasakorn, n.d., slide 3) How does it work? • The bore rotates 1 to 6 times per minute • For treatment delivery the rotation is divided into 51 projections • Each projection covers an arc segment of 7° (Sterzing et al., 2008, slide 24, 29) • Tomotherapy can treat multiple fields at one time (Memorial Care, n.d,) Treatment • Everyday before treatment, a CT verification film is taken • Necessary adjustments are made due to changing tumor volume, weight loss, etc. • Field size can be up to 40 cm wide by 160 cm in length (Mayurasakorn, n.d., slide 2) Treatment • The field can almost be “locked” onto the target http://cms-sp.cityofhope.org/patient_care/treatments/radiationoncology/Pages/helical-tomotherapy.aspx • Patients use standard immobilization devices • Treatment takes just a few minutes like regular RT treatment Treatment • Tomotherapy can be used to treat all types of tumors – Small to large – Confined tumors to multiple metastases – Total body irradiation • Due to the ability to contour tumors, tomotherapy is especially effective for cancers of the head and neck, prostate, brain, breast and lung Treatment • One of the main advantages of tomotherapy is the capability to retreat areas that have previously been irradiated • The precise treatment can distinguish between new cancer growth and scarring. • Surrounding tissues can be spared from further irradiation which prevents further scarring and ulceration Conventional vs. Tomotherapy (Van Dyk et al., n.d., slide 13) Conventional vs. Tomotherapy (BJR, Fig. 3, 2009) Conventional vs. Tomotherapy • http://www.accuray.com/pressroom/vi deo-gallery?page=1&t=18 Trials • Currently there are around 60 trials in different phases from recruiting to completed. – The majority were for cancers surrounded by very critical structures: • Brain, head and neck, prostate, rectal, breast – Others to assess effectiveness of retreatment – Helical tomotherapy vs. other RT treatments (Clinicaltrails.gov) Locations • Tomotherapy can be found in 41 States and 27 countries • Fairview Hospital, University of Minnesota • 11 sites in Wisconsin Disadvantages • Metastases – if a patient has full body metastases this type of precise treatment may miss a rogue cell • There is some question about treating the tumor in fractions instead of as a whole Summary • Sparing of critical structures • Reduced side effects • More precise treatment means larger dose and less fractions leading to decreased treatment days – Prostate cancer can be treated in a week to 2 weeks instead of the usual 7-9 weeks (UCLA Health) • Being able to retreat previously irradiated areas References • Clinicaltrials.gov. (n.d.). Retrieved July 14, 2013, from US National Institutes of Health website: http://clinicaltrials.gov • Curran, B. (n.d.). Intensity modulated radiation therapy using serial tomotherapy. In The American association of physicists in medicine. Retrieved July 11, 2013, from AAPM website: http://www.aapm.org/meetings/03SS/Presentations/ Curran.pdf • Helical TomoTherapy. (n.d.). In City of Hope. Retrieved July 13, 2013, from City of Hope website: http://cmssp.cityofhope.org/patient_care/treatments/radiatio n-oncology/Pages/helical-tomotherapy.aspx References • Mayurasakorn, S. The external beam radiotherapy and image- guided radiotherapy [PowerPoint slides]. Retrieved July 15, 2013 from http://www.docs.google.com • Mackie, T. (2006). History of tomotherapy. Physics in Medicine and Biology, 51(13), 427-453. doi:10.1088/0031-9155/51/13/R54 • Sterzing, Schubert, Sroka-Perez, & Herfarth. (2008, January 11). Helical tomotherapy [PowerPoint slides]. Retrieved July 3, 2013 from http://www.slideshare.net/santam/helicaltomotherapy References • Tomita, N., Kodaira, T., Tachibana, H., Nakamura, T., Nakahara, R., Inokuchi, H., & Takada, A. (2009, April 14). A comparison of radiation treatment plans using IMRT with helical tomotherapy and 3D conformal radiotherapy for nasal natural killer/Tcell lymphoma. In British journal of radiology. doi:10.1259/bjr/83758373 • The TomoTherapy system vs. conventional linacs. (n.d.). In Accuray. Retrieved July 5, 2013, from Accuray Incorporated website: http://www.accuray.com/pressroom/videogallery?page=1&t=18 References • Tomotherapy. (n.d.). In Your guide to cancer care. Retrieved June 30, 2013, from Cancer Compass; Cancer Treatment Centers of America website: http://www.cancercompass.com/cancerguide/conventional-treatment/tomotherapy.html • TomoTherapy. (n.d.). In MemorialCare health system. Retrieved June 30, 2013, from Memorial Care Health System website: http://www.memorialcare.org/medical_services/can cer-care/tomo-therapy.cfm References • TomoTherapy: accurate treatment with fewer side effects. (2013, January 10). In UCLA health. Retrieved June 29, 2013, from UCLA Health website: http://www.uclahealth.org/body.cfm?xyzpdqabc=0& id=502&action=detail&ref=1146&start=2&issueref= 36 • Van Dyk, J., Kron, T., Bauman, G., & Battista, J. (n.d.). Tomotherapy: a "revolution" in radiation therapy. In London health sciences center. Retrieved June 29, 2013, from London Health Sciences website: http://www.lhsc.on.ca/Research_Training/LRCP/Re search_Scientists/Tomotherapy.pdf
