Table 5 Optic sparing, IMRT vs. non-IMRT

Dirix [27]

60-66 Gy/30–33 frx for both IMRT and 3D-CRT

LC: 76% vs. 67% at 2 yrs favoring IMRT (p = 0.06);

ON/OC constraint: ≤ 60 Gy for IMRT.

No vision impairment after IMRT

DFS: 72% vs. 60% at 2 yrs favoring IMRT (p = 0.02)

15.8% radiation induced retinopathy after 3D CRT.

OS: 89% vs. 73% at 2 yrs favoring IMRT (p = 0.07)

Al-Mamgani [28]

IMRT(70%): 60–74 Gy

LC: 80% for IMRT & 64% for 3D CRT (p = 0.2)

Dmax^ǂ (IMRT vs. 3DCRT) when 70 Gy/35 frx was prescribed:

Ocular toxicity: 32% after 3DCRT, 5% after IMRT (p < 0.0001)

3DCRT(30%): 60–70 Gy

OC 47 Gy vs. 54 Gy

Blindness: 1 after IMRT, 3 after 3DCRT

ON

Organ preservation 88% vs. 65% favoring IMRT (p = 0.01)

-Ipsilateral 50 Gy vs. 56 Gy

-Contralateral 42 Gy vs. 48 Gy

Chen [29]

2D 50–74 Gy

LC:

n/a

≥ RTOG grade 3 visual toxicity

3D 50–73 Gy

2D: 55.9%

-2D 20%

IMRT 66–72 Gy

3D: 67%

-3D 9%

IMRT: 69.6%

-IMRT 0%

Blindness is only observed after 2D RT only (5.1% of pts treated with 2D RT)