Int Arch Otorhinolaryngol 2013; 17(02): 163-167
DOI: 10.7162/S1809-97772013000200008
Original Article
Thieme Publicações Ltda Rio de Janeiro, Brazil

Effect of fractionated radiotherapy on the parotid gland: an experimental study in Brazilian minipigs

Roberta Targa Stramandinoli-Zanicotti
1   DDS, MSc, PhD student. Oral and Maxillofacial Surgery Department, Erasto Gaertner Hospital, Curitiba / PR - Brazil; Oncology Department, University of São Paulo, São Paulo / SP - Brazil.
,
Laurindo Moacir Sassi
2   DDS, PhD. Chief of the Oral and Maxillofacial Surgery Department, Erasto Gaertner Hospital, Curitiba / PR - Brazil.
,
Juliana Lucena Schussel
3   DDS, PhD. Oral and Maxillofacial Surgery Department, Erasto Gaertner Hospital, Curitiba / PR - Brazil.
,
Maria Fernanda Torres
4   DVM, PhD. Experimental Surgery Department, Positivo University, Curitiba / PR - Brazil; Veterinary Medicine of Federal University of Parana, Curitiba / PR - Brazil.
,
Melissa Funchal
5   Medical Physics. Radiotherapy Department, Erasto Gaertner Hospital, Curitiba / PR - Brazil.
,
Gustavo Henrique Smaniotto
6   MD. Radiotherapy Department, Erasto Gaertner Hospital, Curitiba / PR - Brazil.
,
José Luis Dissenha
7   DDS. Oral and Maxillofacial Surgery Department, Erasto Gaertner Hospital, Curitiba / PR - Brazil.
,
Andre Lopes Carvalho
8   MD, PhD. Head and Neck Surgery and Otorhinolaryngology Department, Hospital de Cancer de Barretos, Barretos, SP, Brazil; Oncology Department, University of São Paulo, São Paulo / SP - Brazil.
› Author Affiliations
Further Information

Publication History

23 September 2012

03 December 2012

Publication Date:
09 January 2014 (online)

Summary

Introduction: Radiotherapy (RT) of head and neck neoplasms often damages the salivary glands.

Aim: To examine the pattern of morphologic changes resulting from RT of the head and neck region in minipig parotid glands in a clinical and experimental research setting.

Methods: Twelve 18-month-old male Brazilian minipigs weighing 30–40 kg were selected. Eight minipigs were assigned to the experimental group (group 1) and 4 to the control group (group 2). The RT was performed under general anesthesia at Erasto Gaertner Hospital, Curitiba, Brazil, using an á/â ratio of 2.5. The minipigs from group 1 underwent 3 sessions of irradiation with Cobalt 60 of the head and neck, bilaterally, with 3 exposures of 8 Gy each at 7-day intervals for a total dose of 24 Gy. The animals were sacrificed 12 weeks post-RT.

Results: The irradiated parotid glands displayed reductions in the size and number of acini as well as loss of secretory granules. The presence of fibrosis and loss of parenchyma relative to non-irradiated glands were observed, with an average reduction in volume of 54%.

Conclusions: Our results demonstrate that this model for parotid gland damage resulting from an RT regimen appears to be useful for preclinical large animal studies of RT-induced damage and testing novel potential treatment options. Although recent advances in radiation therapy, such as intensity-modulated radiation therapy, have reduced the dose and limited the field of radiation, considerable salivary gland injury still occurs and can greatly impact the patient's quality of life after cancer treatment.

 
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