In Regard to Münter et al. Changes in Salivary Gland Function After Radiotherapy of Head and Neck Tumors Measured by Quantitative Pertechnetate Scintigraphy: Comparison of Intensity-Modulated Radiotherapy and Conventional Radiation Therapy With and Without Amifostine. (Int J Radiat Oncol Biol Phys 2007;67:651–659)

Abstract

To the Editor: We read with interest the article by Münter et al. ( 1 Münter M.W. Hoffner S. Hof H. et al. Changes in salivary gland function after radiotherapy of head and neck tumors measured by quantitative pertechnetate scintigraphy: Comparison of intensity-modulated radiotherapy and conventional radiation therapy with and without amifostine. Int J Radiat Oncol Biol Phys. 2007; 67: 651-659 Abstract Full Text Full Text PDF PubMed Scopus (68) Google Scholar ) that evaluated changes in salivary gland function observed with intensity-modulated radiotherapy (IMRT) vs. conventional radiotherapy (RT) with or without amifostine. We encourage caution in interpreting the results, not only because of the retrospective nature and relatively small sample size of the study, but also because the results contradict the multicenter randomized controlled trial of greater than 300 patients with head-and-neck cancer who received a dose of 50 Gy or greater as postoperative or primary RT with or without amifostine ( 2 Brizel D.M. Wasserman T.H. Henke M. et al. Phase III randomized trial of amifostine as a radioprotector in head and neck cancer. J Clin Oncol. 2000; 18: 3339-3345 PubMed Google Scholar ). Based on the RT dose cutoff values defined by Münter et al. ( 1 Münter M.W. Hoffner S. Hof H. et al. Changes in salivary gland function after radiotherapy of head and neck tumors measured by quantitative pertechnetate scintigraphy: Comparison of intensity-modulated radiotherapy and conventional radiation therapy with and without amifostine. Int J Radiat Oncol Biol Phys. 2007; 67: 651-659 Abstract Full Text Full Text PDF PubMed Scopus (68) Google Scholar ), it appears that all patients in this Phase III study received high-dose RT. Amifostine significantly reduced the overall incidence of Grade 2 or higher acute xerostomia from 78% to 51% (p < 0.0001) and chronic xerostomia (at 1 year) from 57% to 34% (p < 0.002) using Radiation Therapy Oncology Group scores and quantitative saliva production. In addition, with the lack of individual patient details, we are unable to statistically verify the findings from the article by Münter et al. ( 1 Münter M.W. Hoffner S. Hof H. et al. Changes in salivary gland function after radiotherapy of head and neck tumors measured by quantitative pertechnetate scintigraphy: Comparison of intensity-modulated radiotherapy and conventional radiation therapy with and without amifostine. Int J Radiat Oncol Biol Phys. 2007; 67: 651-659 Abstract Full Text Full Text PDF PubMed Scopus (68) Google Scholar ). In lieu of these statements, we would like the following additional information from the investigators: Can the investigators provide data for individual patients with a breakdown of the number in the high vs. low groups of amifostine and IMRT and the doses of RT? For the dose–response analysis, the investigators assumed that the individual glands within a given patient can be treated independently of each other. Can the investigators clarify this assumption? In Reply to Dr. Messerschmidt and Dr. OlekaInternational Journal of Radiation Oncology, Biology, PhysicsVol. 69Issue 5PreviewTo the Editor: Dr. Messerschmidt and Dr. Oleka. compare the results of our study (1), where no beneficial effect of amifostine was seen for the function of individual salivary glands at high doses, with that of Brizel et al. study (2), which demonstrated a significant reduction of acute and chronic xerostomia also for high radiation doses. It has to be noted that the endpoints of these two studies are quite different. Although the scintigraphic method quantitatively measures the function of each individual parotid or submanbibular gland, Brizel et al. Full-Text PDF