This is the largest prospective randomized trial that addressed the value
of beta irradiation after surgical excision of pterygium after that of Jurgenliemk,
86 cases (2), Nakamatsu , 73 cases (3), and De Keizer, 57
cases (4). It is also the first one that compared low-dose fractionation
(20 Gy/10 fractions) with higher dose per fraction regimens (35 Gy/7
The rate of pterygium control was 93.9% with 20 Gray/10 fractions arm
versus 92.3% with the 35 Gray/7 fractions arm which was not far from local
control rates reported by Jurgenliemk (2) with single dose of 25 Gray
(93.2%) and the 90% local control rate reported by De Keizer (4) using
27–30 Gray/3 fractions.
In view of the significant difference between both arms in the incidence
of photophobia, irritation, postoperative granuloma, cosmoses, and scleromalacia
in favor of the low dose per fraction regimen along with the no
difference in the pterygium control rate, the authors recommended the
use of low dose per fraction regimen rather than the hypofractionated
This may be understandable in the light of radiobiological work
conducted by Brenner and Merriam (5), who estimated large value of a/b ratio
of nonrecurrence that suggests improved therapeutic ratio from fractionated
application of b irradiation. But practically speaking, application of
high dose per fraction regimens with doses from 30–60 Gray in three to
six fractions or even a single high dose (2, 6, 7) was not reported to be
associated with high incidence of late complications (e.g., scleromalacia,
sclera ulcers, corneal ulcerations, necrotizing scleritis, maculopathy) that
could occur even with surgery alone without radiotherapy (2, 8, 9).
In the light of the above mentioned discussion, and the many studies that
used high dose per fraction regimens reported in our review article (10), we
recommend the use of the hypofractionated regimens from the prospective
of better patient compliance, especially in centers with limited resources and