Patterns of early treatment failure in non-metastatic nasopharyngeal carcinoma: a study based on CT scanning

Six hundred and twenty-eight patients with non-metastatic nasopharyngeal carcinoma were staged by CT scanning and treated with radical locoregional radiotherapy. Parapharyngeal boost radiation for bulky parapharyngeal involvement, neoadjuvant chemotherapy for bulky nodal metastases, and intracavitary 192Ir treatment for local persistence of tumour after external radiotherapy were also used as appropriate. Forty-eight patients had Ho's (1978) Stage I disease (7.6%), 167 Stage II (26.6%), 312 Stage III (49.7%) and 101 Stage IV (16.1%). At 2 years after treatment, 185 patients (29.5%) had developed recurrence; 112 had distant metastases (60.5%), and 75 had local failure (40.5%). Eighty-three patients had developed distant metastases alone, 73 patients locoregional failure alone and 29 patients had both locoregional and metastatic failure. The overall 2-year actuarial distant and local failure rates were 18.4% and 12.7% respectively. Distant metastasis is the major form of treatment failure which limits early survival. Seventy-four per cent of distant metastases were not associated with locoregional recurrence and had probably arisen from pre-existing occult foci. Our data also suggest that the advent of CT scanning has improved local tumour delineation and radiotherapy planning, and hence local control.