RESUMEN
Malignant melanoma is a type of cancer that most commonly originates from the skin, less frequently from mucosal surfaces, the eye, or meninges [Annu Rev Pathol. 2014;9(1):239-71]. In 2019, this type of malignancy was the third most frequent cancer to be diagnosed in males and the fifth most in females according to the American Cancer Society and the National Cancer Institute [CA Cancer J Clin. 2019;69(5):363-85]. The majority of the malignant melanomas in the head and neck region (85-90%) are cutaneous lesions, most often arising in the skin of the face [Head Neck. 2016;38:147-155]. In sharp contrast are the histological findings of metastatic melanoma with an unknown primary site: they are much more scarce and histologically difficult to diagnose. The literature is limited to case studies or small cohorts. In 2-6% of all patients suffering from metastatic melanoma, after clinical examination of the skin and mucosa, imaging, and other diagnostic examination, a primary tumor cannot be found [Eur J Cancer. 2004;40(9):1454-5]. A very small subgroup (0.5%) presents with a single focus of melanoma within the dermis or subcutaneous tissues [Arch Dermatol. 2000;136(11):1397-9]. We hereby report a case in this subgroup of a solitary melanoma metastasis found in the submandibular gland in a 59-year-old male. The tumor was discovered incidentally after surgical excision of this gland because of nodular enlargement.
RESUMEN
BACKGROUND AND PURPOSE: Conventional radiotherapy is associated with high doses to the salivary glands which causes xerostomia and adverse effects on quality of life. The study aims to investigate the potential of helical tomotherapy (Hi-Art Tomotherapy) to preserve parotid function in head-and-neck cancer patients. PATIENTS AND METHODS: Seven consecutive patients treated with helical tomotherapy at the UZ Brussel, Belgium, were included. During planning, priority was attributed to planning target volume (PTV) coverage: > or =95% of the dose must be delivered to > or =95% of the PTV. Elective nodal regions received 54 Gy (1.8 Gy/fraction). A dose of 70.5 Gy (2.35 Gy/fraction) was prescribed to the primary tumor and pathologic lymph nodes = simultaneous integrated boost scheme. If possible, the mean parotid dose was kept below 26 Gy. Salivary gland function was assessed by technetium scintigraphy. RESULTS: There was a significant dose-response relationship between mean parotid dose and functional recuperation. If the mean dose was kept <31 Gy, a recuperation of 75% can be expected at 12 months. The authors equally observed a significant correlation between salivary excretion (SE) and the percentage of parotid gland receiving a dose <26 Gy (V26%). In order to preserve 75% of SE, 46% of the parotid volume should receive a dose <26 Gy. CONCLUSION: With the use of heLical tomography the parotid gland function can largely be preserved since the mean dose to the entire gland as well as glandular volume receiving >26 Gy can be reduced.