title: [Postoperative external beam radiotherapy for medullary thyroid carcinoma with high risk of locoregional relapse].
abstract: OBJECTIVE
  To assess the outcome of locally advanced medullary thyroid carcinoma treated with surgery and adjuvant external beam radiotherapy.
  
  
  METHODS
  Twenty-nine consecutive patients with non-metastatic medullary thyroid carcinoma treated in our institution between January 1995 and December 2012 were retrospectively evaluated. All underwent curative-intended optimal surgery, followed by external beam radiotherapy because of high risk of locoregional relapse. Twelve patients were stage III, 16 IVa and 1 IVb. Positive surgical margins were present in 11 cases (10 R1 and 1 R2). Median and average preradiotherapy serum calcitonin were 141pg/mL and 699pg/mL, respectively. Fourteen patients received 3D-conformal radiotherapy and 15 received intensity-modulated radiotherapy. Median prescribed dose was 63Gy to the high-risk volumes and 54Gy to the low-risk volumes. Treatment was delivered in 30 fractions. The median gap between surgery and radiotherapy was 1.9months. Median follow-up was 76.4months.
  
  
  RESULTS
  Kaplan-Meier estimates of 5-year locoregional relapse-free survival and overall survival were 79 and 96 %, respectively. Among the five locoregional relapses, two were related to a macroscopic metastatic cervical lymph node that was unfortunately not removed during the lymphadenectomy. Eight of ten patients with microscopic positive margins (R1) were controlled regarding the thyroidectomy bed. Eight patients had normal serum calcitonin after external beam radiotherapy, of whom only one developed a locoregional relapse during follow-up. Regarding the 21 patients with persistent positive serum calcitonin after treatment, only ten developed a macroscopic locoregional or distant relapse. One grade III and no grade IV acute morbidity were reported. Fifteen patients reported grade II chronic morbidity and no grade III/IV.
  
  
  CONCLUSIONS
  Maximal surgery followed by adjuvant external beam radiotherapy as a treatment for locally advanced medullary thyroid carcinoma provides a high rate of long-term locoregional control and overall survival with limited toxicity. Postoperative external beam radiotherapy should be considered when patients present features indicating a high risk of locoregional relapse.
authors.affiliation: Département de radiothérapie, institut universitaire du cancer de Toulouse, 1, avenue Irène-Joliot-Curie, 31059 Toulouse cedex 9, France. Electronic address: francois_compagnon@hotmail.com.
authors.forename: F
authors.initials: F
authors.lastname: Compagnon
authors.affiliation: Département de médecine nucléaire, institut universitaire du cancer de Toulouse, 1, avenue Irène-Joliot-Curie, 31059 Toulouse cedex 9, France.
authors.forename: S
authors.initials: S
authors.lastname: Zerdoud
authors.affiliation: Département de radiothérapie, institut universitaire du cancer de Toulouse, 1, avenue Irène-Joliot-Curie, 31059 Toulouse cedex 9, France.
authors.forename: M
authors.initials: M
authors.lastname: Rives
authors.affiliation: Département de radiothérapie, institut universitaire du cancer de Toulouse, 1, avenue Irène-Joliot-Curie, 31059 Toulouse cedex 9, France.
authors.forename: A
authors.initials: A
authors.lastname: Laprie
authors.affiliation: Département de chirurgie cervicofaciale, institut universitaire du cancer de Toulouse, 1, avenue Irène-Joliot-Curie, 31059 Toulouse cedex 9, France.
authors.forename: J
authors.initials: J
authors.lastname: Sarini
authors.affiliation: Département d'endocrinologie et des maladies métaboliques, centre hospitalier universitaire Larrey, Toulouse, France.
authors.forename: S
authors.initials: S
authors.lastname: Grunenwald
authors.affiliation: Département de biostatistiques, institut universitaire du cancer de Toulouse, 1, avenue Irène-Joliot-Curie, 31059 Toulouse cedex 9, France.
authors.forename: L
authors.initials: L
authors.lastname: Chaltiel
authors.affiliation: Département de radiothérapie, institut universitaire du cancer de Toulouse, 1, avenue Irène-Joliot-Curie, 31059 Toulouse cedex 9, France.
authors.forename: P
authors.initials: P
authors.lastname: Graff
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002116:Calcitonin / Q000097:blood; D018278:Carcinoma, Neuroendocrine / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control*; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant; D020266:Radiotherapy, Conformal; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D013965:Thyroidectomy
chemical_list: D002116:Calcitonin
keywords: Adjuvant; Adjuvante; Cancer médullaire de la thyroïde; Contrôle local; External beam radiotherapy; IMRT; Local control; Medullary thyroid carcinoma; Modulation d’intensité; Postoperative; Postopératoire; Radiothérapie externe