title: Image-guided radiation therapy using surgical clips for localization of colonic metastasis from thyroid cancer.
abstract: A 67-year old man with a history of papillary thyroid cancer (PTC) presented with metastatic disease to the left colon in the form of a 6.1x1.0 cm bleeding, ulcerated mass. Radiopaque surgical clips were used as fiducial markers to localize the gross tumor volume (GTV) as well as the corresponding clinical target volume (CTV) and planning target volume (PTV). Daily cone beam computed tomography (CBCT) image guidance was utilized to verify the tumor position. Inter- and intrafraction movement of the tumor mass was assessed. Gastrointestinal bleeding was controlled using palliative image-guided radiation therapy (IGRT).
authors.affiliation: Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada. alvin.szeto@mail.utoronto.ca.
authors.forename: Alvin
authors.initials: A
authors.lastname: Szeto
authors.affiliation: Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada. lee.chin@sunnybrook.ca.
authors.forename: Lee
authors.initials: L
authors.lastname: Chin
authors.affiliation: Department of Surgery, Markham Stouffville Hospital, Markham, Ontario, Canada. pwhelan@msh.on.ca.
authors.forename: Patrick
authors.initials: P
authors.lastname: Whelan
authors.affiliation: Department of Family and Community Medicine, Markham Stouffville Hospital, Markham, Ontario, Canada. JWilson@msh.on.ca.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Wilson
authors.affiliation: Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada. justin.lee@sunnybrook.ca.
authors.forename: Justin
authors.initials: J
authors.lastname: Lee
mesh_terms: D000328:Adult; D002277:Carcinoma / Q000556:secondary / Q000601:surgery*; D002291:Carcinoma, Papillary; D003110:Colonic Neoplasms / Q000532:radiotherapy* / Q000556:secondary; D057918:Fiducial Markers; D006801:Humans; D008297:Male; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D061089:Radiotherapy, Image-Guided / Q000295:instrumentation / Q000379:methods*; D013525:Surgical Instruments; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000556:secondary / Q000601:surgery*