title: MR and CT based treatment planning for mTHPC mediated interstitial photodynamic therapy of head and neck cancer: description of the method.
abstract: OBJECTIVE
  Interstitial photodynamic therapy is a potentially important tool in the management of voluminous or deep-seated recurrent head and neck cancers.
  
  
  METHODS
  The described treatment algorithm in this manuscript consists of the treatment simulation, implantation of light sources, verification, modification of the treatment plan if necessary, and illumination. The tumor is delineated on imaging sections (CT, MRI, and/or PET/CT) and the treatment is simulated by virtually introducing light sources to the tumor volume on specially modified brachytherapy software. This enables us to determine if the treatment is technically feasible, and information about approximate number and location of light sources necessary. Following implantation of catheters in which the light sources will be introduced, CT or MR scan is performed to verify the actual location of the implanted catheters. The verification-CT is imported to the software and co-registered with pre-treatment images to observe the deviations from the simulation. The simulation is run again with the actual position of the light sources to determine if any additional light sources are necessary and adaptation of the source length in order to cover the tumor volume (modification). Thereafter the tumor is illuminated.
  
  
  RESULTS
  This method has the potential to help with identifying iPDT feasible patients by simulating before the actual treatment. The suboptimal placement of light sources can be identified and corrected. The simulations were documented and saved for subsequent evaluation of the technique.
  
  
  CONCLUSIONS
  The proposed technique can help standardize and document iPDT.
authors.affiliation: Department of Head and Neck Oncology and Surgery, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Baris
authors.initials: B
authors.lastname: Karakullukcu
authors.forename: Robert L P
authors.initials: RL
authors.lastname: van Veen
authors.forename: Jan Bonne
authors.initials: JB
authors.lastname: Aans
authors.forename: Olga
authors.initials: O
authors.lastname: Hamming-Vrieze
authors.forename: Arash
authors.initials: A
authors.lastname: Navran
authors.forename: H Jelle
authors.initials: HJ
authors.lastname: Teertstra
authors.forename: Ferrie
authors.initials: F
authors.lastname: van den Boom
authors.forename: Yuri
authors.initials: Y
authors.lastname: Niatsetski
authors.forename: H J C M
authors.initials: HJ
authors.lastname: Sterenborg
authors.forename: I Bing
authors.initials: IB
authors.lastname: Tan
mesh_terms: D000465:Algorithms; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000188:drug therapy*; D003661:Decision Support Techniques; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008652:Mesoporphyrins / Q000627:therapeutic use*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000188:drug therapy; D010347:Patient Care Planning; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D049268:Positron-Emission Tomography; D012984:Software; D014057:Tomography, X-Ray Computed; D014062:Tongue Neoplasms / Q000175:diagnosis / Q000188:drug therapy*
chemical_list: D000970:Antineoplastic Agents; D008652:Mesoporphyrins; D017319:Photosensitizing Agents; C072269:temoporfin
keywords: advanced head and neck cancer; imaging; modification; simulation; treatment planning; verification