Image-guided high-dose-rate interstitial brachytherapy boost in the radical radiotherapy for a huge metastatic carcinoma of cervical lymph nodes from an unknown primary site.

The purpose of this article was to report the treatment effect of image-guided high-dose-rate interstitial brachytherapy boost in the radical radiotherapy for a huge metastatic carcinoma of cervical lymph nodes from an unknown primary site. The patient was a 75-year-old male. A diagnostic biopsy showed metastatic squamous cell carcinoma and the tumour size was 7.5 × 6.5 × 11.5 cm3 before treatment (N3; AJCC 7th). After external beam radiotherapy with a dose of 60 Gy in 30 fractions, the residual tumour (6.2 × 4.7 × 6.0 cm3) was treated with image-guided high-dose-rate interstitial brachytherapy boost under ultrasound guidance. The brachytherapy dose was 16 Gy in four fractions of 4 Gy each. Removal of the huge metastatic tumour was securely achieved by high dose rate interstitial brachytherapy guided with ultrasound scanning. The refractory tumour in the patients healed uneventfully after image-guided high-dose-rate interstitial brachytherapy without recurrence during the 24 months of follow-up. The image-guided high-dose-rate interstitial brachytherapy boost may be a proposed treatment strategy for metastatic carcinoma of cervical lymph nodes from an unknown primary site with radical radiotherapy, especially for huge residual tumour. [ABSTRACT FROM AUTHOR]