The primary tumor regression pattern of 50 patients with nasopharyngeal carcinoma was reported. The tumor regression was monitored either by indirect nasopharyngeal mirror examination and biopsy or fiberoptic endoscope and biopsy. Fiberoptic endoscope and biopsy was found to be more accurate in noting residual tumor. It is recommended that booster radiation dose to the residual primary tumors be withheld unless positive biopsy samples persist at 10 or more weeks after radiotherapy.
Cancer 65:216-220, 1990.
ADIOTHERAPY is the definitive treatment for naso-R pharyngeal carcinoma, but relapse in the nasopharynx is not an uncommon cause of failure.' The prognosis of this group of patients is poor; the median survival after relapse in the primary site was 10 months.' The management of recurrent nasopharyngeal carcinoma posts many problems. Previous radical radiation to the radiosensitive structures adjacent to the nasopharynx limits the dose of radiation that can be given again safely for recurrent primary disease.
Local relapses result from regrowth of local persistent disease. Radiobiologically, it is sound to treat persistent tumors before they regrow, because the target volume will be smaller and the dose of radiation required will be less.3 Furthermore, early treatment of these persistent tumors will prevent metastases.
The response of carcinoma of cervix to a test dose of radiation was shown to correlate with the ultimate cure rate.4 Positive biopsy after radiotherapy for carcinoma of prostate was correlated with increased local recurrence and worse progno~is.~,~ To our knowledge, no similar study on nasopharyngeal carcinoma had been done be-