Management of local residual primary lesion of nasopharyngeal carcinoma: II. Results of prospective randomized trial on booster dose.
Although the question of booster dose for residual primary lesion arises in only 5% of nasopharyngeal carcinoma patients receiving radiotherapy, it poses a difficult problem for clinicians and should be followed. Hence, to test the validity of booster dose for residual primary lesion of nasopharyngeal carcinoma, a prospective randomized trial has been designed and carried out since January 1980. All patients who had a residual lesion in the nasopharynx at 70 Gy were biopsied. Those pathologically positive for cancer were randomized into two groups: (a) positive radiation group (PRG): patients were given further irradiation to a total dose of 90 Gy by the cone-down and assault technique, and (b) positive observation group (POG): patients were given no more irradiation but were followed periodically together with those who were pathology negative (NOG). A total of 78 patients were entered. The validity of booster dose was shown by the 5-year survival rates of the PRG, POG and NOG groups: 75% (3/4), 33% (1/3), and 58% (14/24), respectively. The total local recurrence rates of these groups were 6% (1/16), 36% (5/14), and 4% (2/48), respectively. The authors believe that booster dose for pathology positive residual lesion in the nasopharynx is necessary. The four factors leading to the development of a local recurrence are: (a) residual primary lesion proved positive by pathology but left unboosted, (b) well differentiated squamous cell carcinoma in the original primary lesion, (c) mild radio-response in the cancer parenchyma, and (d) mild radio-response in the interstitial tissue.
Yan
J H
JH
Dept. Radiation Oncology, Cancer Hospital, Chinese Academy of Medical Sciences, Beijing.
Xu
G Z
GZ
Hu
Y H
YH
Li
S Y
SY
Lie
Y Z
YZ
Qin
D X
DX
Wu
X L
XL
Gu
X Z
XZ
D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy; D006801:Humans; D009303:Nasopharyngeal Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D016032:Randomized Controlled Trials as Topic; D015996:Survival Rate