General concepts in head and neck radiotherapy
Radiation Therapy for Head and Neck Cancers: A Case-Based Review, Springer International Publishing Ag, ss.1-15, 2015
- Yayın Türü: Kitapta Bölüm / Araştırma Kitabı
- Basım Tarihi: 2015
- Doi Numarası: 10.1007/978-3-319-10413-3_1
- Yayınevi: Springer International Publishing Ag
- Sayfa Sayıları: ss.1-15
- Sağlık Bilimleri Üniversitesi Adresli: Evet
Özet
Head and neck cancers mostly follow an orderly and predictable spread pattern. Approximately two thirds of the patients have locally advanced disease at presentation. A tendency towards local or regional spread is common in head and neck cancers. Regional involvement is frequently concerned with the primary tumor's anatomic location and extent. Despite the increased risk of hematogenous spread in the presence of enlargement and extracapsular extension of the involved neck nodes, distant metastasis constitutes an infrequent pattern of failure, which allows potential cure by optimal management strategies. Nevertheless, head and neck tumor sites of the nasopharynx and hypopharynx have a relatively higher likelihood for distant spread. The most common site of distant failure is the lungs followed by the bones, mediastinal lymphatics, liver, and brain secondaries. However, atypical distant involvement of cutaneous and subcutaneous tissues may occur in patients with radical neck dissection or previous radiotherapy. Due to the risk of nerve invasion for some head and neck tumors, particularly for parotid cancers, nerve traces should meticulously be considered in the treatment planning process.