Impact of local tumor relapse on patient survival after cobalt 60 plaque radiotherapy.
The authors investigated the impact of local intraocular tumor relapse on survival in a matched-group comparison study of patients with primary choroidal or ciliary body melanoma managed with cobalt 60 plaque radiotherapy. Sixty-two patients with local relapse were matched with an equal number of relapse-free patients in terms of known clinical prognostic factors for both melanoma-specific mortality (largest linear tumor dimension, location of anterior tumor margin, age) and local tumor relapse (location of posterior tumor margin). The follow-up of every relapse-free patient equaled or exceeded the interval to relapse for each matched patient with local relapse. The estimated 5-year survival (Kaplan-Meier) in the relapse-free patients was 87% (standard error = 4%), while that in the local relapse group was 58% (standard error = 6%). This difference is statistically significant (P less than 0.0001, log rank test). These results support the hypothesis that local tumor relapse after cobalt 60 plaque radiotherapy is an important post-treatment clinical indicator of the tumor's greater malignant potential and the patient's increased risk of melanoma-specific mortality.
Vrabec
T R
TR
Wills Eye Hospital, Department of Ophthalmology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107.
Augsburger
J J
JJ
Gamel
J W
JW
Brady
L W
LW
Hernandez
C
C
Woodleigh
R
R
D000328:Adult; D000368:Aged; D001918:Brachytherapy; D002830:Choroid Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D002924:Ciliary Body / Q000528:radiation effects; D003037:Cobalt Radioisotopes / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008545:Melanoma / Q000401:mortality / Q000532:radiotherapy*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality*; D011379:Prognosis; D015996:Survival Rate; D014604:Uveal Neoplasms / Q000401:mortality / Q000532:radiotherapy*
D003037:Cobalt Radioisotopes