title: [Helical tomotherapy in the treatment of malignant pleural mesothelioma: The impact of low doses on pulmonary and oesophageal toxicity].
abstract: OBJECTIVE
  To evaluate the adjuvant treatment of malignant pleural mesothelioma by helical tomotherapy and the impact of low doses on esophageal and pulmonary toxicity.
  
  
  METHODS
  Between June 2007 and May 2011, 29 patients diagnosed with malignant pleural mesothelioma received adjuvant radiotherapy by helical tomotherapy. The median age was 63 years (34-72). Histologically, 83 % of patients had epithelioid malignant pleural mesothelioma. Clinically, 45 % of patients were T3 and 55 % N0. Eighty six percent of the patients were treated by extrapleural pneumonectomy and 35 % received neoadjuvant chemotherapy with platinum and pemetrexed. The median dose in the pneumonectomy cavity was 50Gy at 2Gy/fraction.
  
  
  RESULTS
  The mean follow-up was 2.3 years after diagnosis. Overall survival at 1 and 2 years was 65 and 36 % respectively. The median survival from diagnosis was 18 months. Median lung volumes receiving 2, 5, 10, 13, 15 and 20Gy (V2, V5, V10, V13, V15 and V20) were 100, 98, 52, 36, 19 and 5 %. The median of the mean remaining lung dose was 11Gy. Two patients died of pulmonary complications, three patients had grade 3 lung toxicity, while esophageal grade 3-4 toxicity was observed in three other patients. No significant impact of clinical characteristics and dosimetric parameters were found on pulmonary toxicity, however a V10≥50 %, a V15≥15 % and mean lung dose of 10Gy or more had a tendency to be predictive of pulmonary toxicity (P<0.1). Moreover, in our analysis, the mean lung dose seems to have a significant impact on esophageal toxicity (P=0.03) as well as low doses to the controlateral lung: V5, V10 and V13 (P<0.05).
  
  
  CONCLUSIONS
  Helical tomotherapy is a promising technique in the multimodality treatment of malignant pleural mesothelioma. Low doses received by the contralateral lung appear to be the limiting factor. A dosimetric comparison with volumetric modulated arctherapy techniques would be interesting in this setting.
authors.affiliation: Service d'oncologie radiothérapie, hôpital européen Georges-Pompidou, 20, rue Leblanc, 75015 Paris, France. Electronic address: heloujoelle@gmail.com.
authors.forename: J
authors.initials: J
authors.lastname: Helou
authors.forename: K
authors.initials: K
authors.lastname: Clément-Colmou
authors.forename: A
authors.initials: A
authors.lastname: Sylvestre
authors.forename: L
authors.initials: L
authors.lastname: Campion
authors.forename: M
authors.initials: M
authors.lastname: Amessis
authors.forename: S
authors.initials: S
authors.lastname: Zefkili
authors.forename: J
authors.initials: J
authors.lastname: Raphael
authors.forename: P
authors.initials: P
authors.lastname: Bonnette
authors.forename: F
authors.initials: F
authors.lastname: Le Pimpec Barthes
authors.forename: C
authors.initials: C
authors.lastname: Périgaud
authors.forename: M A
authors.initials: MA
authors.lastname: Mahé
authors.forename: P
authors.initials: P
authors.lastname: Giraud
mesh_terms: D000328:Adult; D000368:Aged; D004947:Esophagus / Q000528:radiation effects*; D005260:Female; D006801:Humans; D008168:Lung / Q000528:radiation effects*; D008175:Lung Neoplasms / Q000532:radiotherapy*; D008297:Male; D008654:Mesothelioma / Q000532:radiotherapy*; D000086002:Mesothelioma, Malignant; D008875:Middle Aged; D011013:Pneumonectomy; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant; D050397:Radiotherapy, Intensity-Modulated
keywords: Faibles doses; Helical tomotherapy; Low doses; Malignant pleural mesothelioma; Mésothéliome pleural malin; Tomothérapie hélicoïdale; Toxicity; Toxicités