title: In vivo dosimetry in intraoperative electron radiotherapy: microMOSFETs, radiochromic films and a general-purpose linac.
abstract: BACKGROUND
  In vivo dosimetry is desirable for the verification, recording, and eventual correction of treatment in intraoperative electron radiotherapy (IOERT). Our aim is to share our experience of metal oxide semiconductor field-effect transistors (MOSFETs) and radiochromic films with patients undergoing IOERT using a general-purpose linac.
  
  
  METHODS
  We used MOSFETs inserted into sterile bronchus catheters and radiochromic films that were cut, digitized, and sterilized by means of gas plasma. In all, 59 measurements were taken from 27 patients involving 15 primary tumors (seven breast and eight non-breast tumors) and 12 relapses. Data were subjected to an outliers' analysis and classified according to their compatibility with the relevant doses. Associations were sought regarding the type of detector, breast and non-breast irradiation, and the radiation oncologist's assessment of the difficulty of detector placement. At the same time, 19 measurements were carried out at the tumor bed with both detectors.
  
  
  RESULTS
  MOSFET measurements ([Formula: see text]  = 93.5 %, sD  =  6.5 %) were not significantly shifted from film measurements ([Formula: see text]  =  96.0 %, sD  =  5.5 %; p  =  0.109), and no associations were found (p = 0.526, p = 0.295,  and p = 0.501, respectively). As regards measurements performed at the tumor bed with both detectors, MOSFET measurements ([Formula: see text]  =  95.0 %, sD  =  5.4 % were not significantly shifted from film measurements ([Formula: see text]  =  96.4 %, sD  =  5.0 %; p  =  0.363).
  
  
  CONCLUSIONS
  In vivo dosimetry can produce satisfactory results at every studied location with a general-purpose linac. Detector choice should depend on user factors, not on the detector performance itself. Surgical team collaboration is crucial to success.
authors: Servicio de Radiofísica y Protección Radiológica, Consorcio Hospitalario Provincial de Castellón, Avenida Dr. Clará, nº 19, 12002, Castellón de la Plana, Spain, lopez_juatar@gva.es.
authors: Juan
authors: J
authors: López-Tarjuelo
authors: Ana
authors: A
authors: Bouché-Babiloni
authors: Virginia
authors: V
authors: Morillo-Macías
authors: Noelia
authors: N
authors: de Marco-Blancas
authors: Agustín
authors: A
authors: Santos-Serra
authors: Juan David
authors: JD
authors: Quirós-Higueras
authors: Carlos
authors: C
authors: Ferrer-Albiach
mesh_terms: D004583:Electrons / Q000627:therapeutic use; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005373:Film Dosimetry / Q000295:instrumentation*; D006801:Humans; D007430:Intraoperative Care / Q000295:instrumentation; D009369:Neoplasms / Q000532:radiotherapy*; D010315:Particle Accelerators / Q000295:instrumentation*; D018714:Radiotherapy, Adjuvant / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014173:Transistors, Electronic