Current problems in radiotherapy, chemotherapy and staging of nasopharyngeal carcinoma (NPC).
Nasopharyngeal carcinoma (NPC) in South East Asia is almost entirely of the undifferentiated or poorly differentiated squamous cell types which are more radiosensitive and have better prospect for locoregional control. Cross-sectional imaging can now detect disease in the parapharynx which is commonly involved by this carcinoma. This has resulted in up-staging and technique modification for better local control. Poor prognostic factors include parapharyngeal, skull bone, cranial nerve or other wide-spread involvements locally. Neck nodes in the supraclavicular fossae or bulky nodes also confer poor prognoses. A simplified staging classification system is proposed. With the availability of afterloading machines, a booster dose of intracavitary radiotherapy can conveniently be given. When given shortly after the usual external radiotherapy, the desired high dose to the primary can be achieved without increasing the risk of long-term side effects. Chemotherapy given before radiotherapy helps to achieve prompt control of bulky neck nodes which distort the anatomy and pose problems in radiotherapy dosimetry. However, the eventual survival rate is still not improved. As staging and major prognostic factors are better defined, trials of adjuvant chemotherapy given after radiotherapy should be undertaken. However, the ultimate control of NPC may rest on the feasibility studies on screening for early NPC.
Tsao
S Y
SY
Therapeutic Radiology Department, Singapore General Hospital.
Chua
E T
ET
D002277:Carcinoma / Q000473:pathology / Q000532:radiotherapy / Q000628:therapy*; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D008297:Male; D009303:Nasopharyngeal Neoplasms / Q000473:pathology / Q000628:therapy*; D009305:Nasopharynx / Q000000981:diagnostic imaging / Q000473:pathology; D009367:Neoplasm Staging; D011859:Radiography