Results of a multicentre randomised controlled trial of cochlear-sparing intensity-modulated radiotherapy versus conventional radiotherapy in patients with parotid cancer (COSTAR; CRUK/08/004). (November 2018)

• Record Type: Journal Article
• Authors: Nutting, Christopher M.; Morden, James P.; Beasley, Matthew; Bhide, Shreerang; Cook, Audrey; De Winton, Emma; Emson, Marie; Evans, Mererid; Fresco, Lydia; Gollins, Simon; Gujral, Dorothy; Harrington, Kevin; Joseph, Mano; Lemon, Catherine; Luxon, Linda; van den Blink, Qurrat; Mendes, Ruheena; Miah, Aisha; Newbold, Kate; Prestwich, Robin; Robinson, Martin; Sanghera, Paul; Simpson, Joanna; Sivaramalingam, Muthiah; Srihari, Narayanan Nair; Sydenham, Mark; Wells, Emma; Witts, Stephanie; Hall, Emma
• Is Part Of: European journal of cancer. Volume 103(2018)
• Page Start: 249
• Page End: 258
• Publication Date: 2018-11
• Subjects: Radiotherapy -- Head and neck cancer -- Cochlear-sparing -- IMRT -- Hearing loss; Cancer -- Periodicals; Neoplasms -- Periodicals; Cancer -- Périodiques; Cancer; Tumors; Electronic journals; Periodicals; Electronic journals; 616.994
• DOI: 10.1016/j.ejca.2018.08.006
• Languages: English
• ISSNs: 0959-8049

Abstract

Abstract: Purpose: About 40–60% of patients treated with post-operative radiotherapy for parotid cancer experience ipsilateral sensorineural hearing loss. Intensity-modulated radiotherapy (IMRT) can reduce radiation dose to the cochlea. COSTAR, a phase III trial, investigated the role of cochlear-sparing IMRT (CS-IMRT) in reducing hearing loss. Methods: Patients (pT1-4 N0-3 M0) were randomly assigned (1:1) to 3-dimensional conformal radiotherapy (3DCRT) or CS-IMRT by minimisation, balancing for centre and radiation dose of 60Gy or 65Gy in 30 daily fractions. The primary end-point was proportion of patients with sensorineural hearing loss in the ipsilateral cochlea of ≥10 dB bone conduction at 4000 Hz 12 months after radiotherapy compared using Fisher's exact test. Secondary end-points included hearing loss at 6 and 24 months, balance assessment, acute and late toxicity, patient-reported quality of life, time to recurrence and survival. Results: From Aug 2008 to Feb 2013, 110 patients (54 3DCRT; 56 CS-IMRT) were enrolled from 22 UK centres. Median doses to the ipsilateral cochlea were 3DCRT: 56.2Gy and CS-IMRT: 35.7Gy (p < 0.0001). 67/110 (61%) patients were evaluable for the primary end-point; main reasons for non-evaluability were non-attendance at follow-up or incomplete audiology assessment. At 12 months, 14/36 (39%) 3DCRT and 11/31 (36%) CS-IMRT patients had ≥10 dB loss (p = 0.81). No statistically significant differences were observed in hearing loss at 6 or 24 months or in other secondary end-points including patient-reported hearing outcomes. Conclusion: CS-IMRT reduced the radiation dose below the accepted tolerance of the cochlea, but this did not lead to a reduction in the proportion of patients with clinically relevant hearing loss. Highlights: Ipsilateral hearing loss is experienced by 35–40% of patients having radiotherapy to their parotid. Reducing the radiation dose to the cochlea does not spare hearing loss. The radiosensitivity of the cochlea may be much greater than previously understood.