title: [Microscopic extensions of head and neck squamous cell carcinomas: impact for clinical target volume definition].
abstract: OBJECTIVE
  To assess microscopic extensions of head and neck squamous cell carcinomas aiming at a proposal for target volumes of radiation therapy.
  
  
  METHODS
  Surgical specimens were prospectively analysed macroscopically and microscopically. Tumour borders were identified per macroscopic visual examination and inked on stained slides. Then microscopic implants (perineural or lymphatic involvement, or in situ carcinomas) were looked for with an optic microscope in the macroscopic healthy tissue surrounding the tumour. The maximal length from tumour border was correlated with the maximal length of macroscopically healthy tissues assessable.
  
  
  RESULTS
  Twenty-one specimens were analysed and 12 were locally advanced tumours. Mean and median maximal microscopic extensions were 2.9 and 1.0mm (0-15mm), respectively. The 90th and 95th percentiles were 5 and 11mm, respectively. The ratio between healthy tissue length and maximal microscopic tumour extension was 10%. No correlation was found with tumour grade or volume.
  
  
  CONCLUSIONS
  The presence of microscopic tumour was unlikely after 5mm from macroscopic tumour (≤5% of patients in this series) but should be assessed along with other histoclinical factors and particularities of tumour behaviour by anatomic site. A rigorous terminology should authorize a relevant appreciation of local risk of recurrence, particularly in adjuvant setting or for clinical target volume definition. Larger and more homogenous confirmatory series are needed.
authors: Centre de radiothérapie Marie-Curie, 159, boulevard du Maréchal-Juin, 26000 Valence, France. Electronic address: bertrand.fleury@gmx.fr.
authors: B
authors: B
authors: Fleury
authors: Département de radiothérapie, centre Antoine-Lacassagne, université Nice-Sophia Antipolis, 33, avenue de Valombrose, 06000 Nice, France.
authors: J
authors: J
authors: Thariat
authors: Département de cytologie et anatomopathologie, hôpital de la Croix-Rousse, 103, Grande-Rue-de-la-Croix-Rousse, 69317 Lyon, France.
authors: R
authors: R
authors: Barnoud
authors: Département de chirurgie ORL, centre hospitalier de Valence, 179, avenue du Maréchal-Juin, 26000 Valence, France.
authors: G
authors: G
authors: Buiret
authors: Département de cytologie et anatomopathologie, hôpital de la Croix-Rousse, 103, Grande-Rue-de-la-Croix-Rousse, 69317 Lyon, France.
authors: F
authors: F
authors: Lebreton
authors: Département de cytologie et anatomopathologie, hôpital de la Croix-Rousse, 103, Grande-Rue-de-la-Croix-Rousse, 69317 Lyon, France.
authors: B
authors: B
authors: Bancel
authors: Département de chirurgie ORL, hôpital de la Croix-Rousse, 103, Grande-Rue-de-la-Croix-Rousse, 69317 Lyon, France.
authors: M
authors: M
authors: Poupart
authors: Département de cytologie et anatomopathologie, hôpital de la Croix-Rousse, 103, Grande-Rue-de-la-Croix-Rousse, 69317 Lyon, France.
authors: M
authors: M
authors: Devouassoux-Shisheboran
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology* / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D008297:Male; D008853:Microscopy; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011446:Prospective Studies; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal; D013194:Staining and Labeling
keywords: Carcinome épidermoïde ORL; Conformal radiotherapy; Head and neck squamous cell carcinomas; Histology; Radiothérapie conformationnelle; Target volumes; Volume cible