PET scanning and Gamma Knife radiosurgery in the early diagnosis and salvage "cure" of locally recurrent nasopharyngeal carcinoma.

"Gamma Knife radiosurgery" is high-dose conformal radiation therapy used for the treatment of small target lesions in the head. It is a minimally invasive technique of multiple fixed, precisely aimed cobalt beams, and relies upon strict patient immobilization via a pinned stereotactic frame to deliver treatment to a precisely located target within a coordinated mapping system. This technique has been widely validated for the treatment of intra-cranial neoplasms and arteriovenous malformations. In this manuscript, two cases of early diagnosed, locally recurrent (persistent) nasopharyngeal carcinoma, successfully treated by Gamma Knife, are described. In one of these, early diagnosis by PET scanning may have improved the chance of cure.