title: Recommendations from Gynaecological (GYN) GEC-ESTRO Working Group (I): concepts and terms in 3D image based 3D treatment planning in cervix cancer brachytherapy with emphasis on MRI assessment of GTV and CTV.
abstract: OBJECTIVE
  Brachytherapy (BT) plays a crucial role in the management of invasive cervix cancer from stage I to IV. Intracavitary techniques are based on afterloading devices, with different types of applicators. CT and/or MRI compatible applicators allow a sectional image based approach with a better assessment of gross tumour volume (GTV) and definition and delineation of target volume (CTV) compared to traditional approaches. Accurate and reproducible delineation of GTV, CTV and PTV, as well as of critical organs has a direct impact on BT treatment planning, especially if it is possible to adapt the pear-shape isodose by optimisation using DVH analysis. When introducing a 3D image based approach for GTV and CTV assessment, there is a need for a common language to describe the concepts and to define the terms which are to be used.
  
  
  METHODS
  In 2000, GEC-ESTRO decided to support 3D imaging based 3D treatment planning approach in cervix cancer BT with the creation of a Working Group. The task was to describe basic concepts and terms and to work out a terminology enabling various groups working in this advanced field to use a common language. The recommendations described in this report were proposed based on clinical experience and dosimetric concepts of different institutions (IGR, Leuven, Vienna) and were stepwise validated against the background of different clinical experience.
  
  
  CONCLUSIONS
  As GTV and CTV for BT change significantly during treatment, time frame for assessment of GTV and CTV for BT is specified in this report: at time of diagnosis GTV(D), CTV(D) and at time of BT GTV(B), CTV(B). Furthermore, CTV for BT is defined related to risk for recurrence: high risk CTV and intermediate risk CTV. Beside verbal descriptions detailed examples are given, partly in form of schematic drawings.
authors.affiliation: Department of Radiotherapy, Brachytherapy Unit, Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Haie-Meder
authors.forename: Richard
authors.initials: R
authors.lastname: Pötter
authors.forename: Erik
authors.initials: E
authors.lastname: Van Limbergen
authors.forename: Edith
authors.initials: E
authors.lastname: Briot
authors.forename: Marisol
authors.initials: M
authors.lastname: De Brabandere
authors.forename: Johannes
authors.initials: J
authors.lastname: Dimopoulos
authors.forename: Isabelle
authors.initials: I
authors.lastname: Dumas
authors.forename: Taran Paulsen
authors.initials: TP
authors.lastname: Hellebust
authors.forename: Christian
authors.initials: C
authors.lastname: Kirisits
authors.forename: Stefan
authors.initials: S
authors.lastname: Lang
authors.forename: Sabine
authors.initials: S
authors.lastname: Muschitz
authors.forename: Juliana
authors.initials: J
authors.lastname: Nevinson
authors.forename: An
authors.initials: A
authors.lastname: Nulens
authors.forename: Peter
authors.initials: P
authors.lastname: Petrow
authors.forename: Natascha
authors.initials: N
authors.lastname: Wachter-Gerstner
mesh_terms: D001918:Brachytherapy / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D010347:Patient Care Planning; D011874:Radiometry; D009626:Terminology as Topic; D002583:Uterine Cervical Neoplasms / Q000473:pathology* / Q000532:radiotherapy*