Article
Impact of radiotherapy on laryngeal intrinsic muscles
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Authors
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Miroslav Tedla
- University ENT dpt Bratislava, Bratislava, Slovakia
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Matus Valach
- Institut fur Pathologie, Wiener Neustadt, Austria
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Ricardo Carrau
- John Wayne Cancer Institute at Saint John's Health Center, Santa Monica, USA
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Peter Weismann
- Institute of Anatomy, Medical School, Bratislava, Slovakia
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Milan Profant
- University ENT dpt, Bratislava, Slovakia
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Ivan Varga
- Institute of Histology and Embryology, Medical School, Bratislava, Slovakia
| Published: | April 19, 2011 |
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Outline
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Introduction: Ionizing radiation as a cancer therapy is associated with a variety of undesirable side effects. Clinical observations have identified problems with swallowing and voice function, presenting as aspiration of saliva and food, hoarseness and vocal fatigue. Our study aims to evaluate the impact of radiotherapy on laryngeal soft tissues using image analysis to quantify its effect on the structure of the vocalis and thyroarytenoid muscles.
Methods: We collected total laryngectomy specimens from patients who had received preoperative radiotherapy (60–66 Gy). The control group consisted of total laryngectomy specimens from patients who underwent surgery as primary treatment. Sampling of the specimens only included non-cancerous laryngeal tissue. Laryngeal histological slices were evaluated using digital morphometric analysis system.
Results: Percentage of fibrosis and density of muscle fibers within the thyroarytenoid muscle were evaluated in both groups. We found no significant quantitative differences in muscle fibrosis (7.92% vs. 7.52%, P>0.1). A significant reduction of muscle fibers, however, was observed in the samples from irradiated larynxes (66.45% vs. 42.03%, P<0.01).
Conclusions: Our analysis suggests that radiotherapy is responsible for a significant reduction in muscle fibers in the thyroarytenoid muscle and that these changes occur during treatment or relatively early after its completion. Quantitative changes in the degree of fibrosis were not confirmed. We recognize, however, that these changes may be time dependent and that they may develop at a time frame that extends beyond that included in our study.
