Orbital and Ocular Tumors

Incidence

  • metastatic tumors are the most common intraocular malignancy
  • Uveal melanoma is the most common primary malignant intraocular neoplasm

Anatomy of the Eye

  • Uvea is the pigmented layer of the eye that includes the iris, ciliary body, and choroid
  • The iris functions as a diaphragm, constantly altering the size of the pupil according to the ambient light.
  • The ciliary body is continuous with the iris, and it lines the sclera anteriorly. Its functions include secretion of aqueous fluid and alteration of the shape of the crystalline lens for the purpose of focusing.
  • Posterior to the ciliary body is the choroid, a pigmented tissue full of blood vessels which nourish the retina. The choroid lines the remainder of the sclera

Ocular Metastasis

  • Metastases most often originate from breast (62%) or lung (26%) [6]
  • Lobular carcinoma is the histology most frequently associated with choroidal metastasis
  • 40 Gy is an effective and safe palliative treatment for symptomatic and asymptomatic choroidal metastases to preserve vision in the majority of the patients

Grave’s Disease

RT dose:

  • 20 Gy in 10 fractions

Results of RT

  • Radiation improves eye muscle mobility, resulting in less diplopia
  • Its effect on proptosis is insignificant as with cortiosteroids.

Pterygium

  • fibrovascular growth on cornea
  • Surgical resection to level of Tenon's capsule has recurrence rate of 20%-68%
  • postoperative adjuvnat therapy reduces recurrence
    • radiation
    • topical thiotepa
    • mitocycine-C
    • antimetabolic agents

RT

  • beta-emitters started within 24 hours of surgery
  • dose: 10-60 Gy in 1 to 6 fractions

Randomized trial[1]

Treatment arms Control rate
25 Gy Sr-90 brachytherapy 93%
sham radiation 33%

Ocular Melanoma

General

  • Uveal melanoma is the most common primary malignant intraocular neoplasm with 1,500 cases per year.
  • The diagnosis is based on opthalmoscopic appearance. No biopsy is needed.
  • The tumor typically appears as a unilateral, solitary, elevated, dark brown or gray, variable pigmented, dom-shaped mass.

Studies

  • The 2 COMS clinical trials are Pre-Enucleation Radiation for large choriodal melanoma and I-125 Brachytherapy for Medium Choroidal Melanoma.
  • Both trials show equivalent survival

COMS for Large Choroidal Melanoma.[4][5]
Pre-operative RT for Locally advanced disease

  • 20 Gy pre-op vs enucleation alone
  • No benefit in local control
  • OS-5 was 40%

Results

  • 5-year survival rates for enucleation vs. pre-enucleation with radiation was 57% and 62%, respectively (p = 0.32)
  • Mortality rates did not differ between enucleation arm and pre-enucleation ration arm.
  • Adjusted 10-year all-cause mortality rates for enucleation arm and pre-enucleation radiation arm were 61% and 62%, respectively
  • 5-yr metastatic melanoma rate ~ 25% and 10-yr metastatic melanoma rate ~40%.

COMS for Medium Choroidal Melanoma
Eligibility:

  • 2.5 to 10.0 mm in apical height and
  • < 16.0 mm in longest basal diameter.

Definitive RT (brachytherapy) dose

  • 85 Gy to the apex at 0.5 to 1.25 Gy/hr with I-125 plaque therapy

Results:

  • Unadjusted estimated 5-year survival rates for enucleation vs. radiation was 81% and 82%, respectively (p = 0.48)
  • 63% with visual acuity of ≥20/200 by 3 years of treatment
  • 90% had retinopathy
  • 85% retained their eyes for ≥5 years

Macular Degeneration, Causes for Age-related

  • Atrophic retinal epithelium and choriocapillaris in the macula (Dry AMD)
  • Subretinal neovascularization (Wet AMD)

Treatment

  • No role for RT at this time
  • Randomized trials from Netherland treated 34 pts with 24 Gy and had proglonged time until vision decreased.
  • Multiple other trials showed no difference.

Ocular Lymphoma

  • Eye or ocular lymphoma is a primary CNS lymphoma
    • 20% of Primary CNS lymphoma have ocular involvement
    • 80-90% of ocular lymphoma will eventually involve the CNS

Treat like CNS lymphoma

Orbital lymphoma

  • NHL of the body and not a primary CNS lymphoma.
  • Usually metastatic
  • High-grade is associated with 60% distant relapse rate
  • < 5% of orbital lymphoma have CNS involvement

Treat like NHL of body

  • RT alone is accepted for low-grade
  • Chemotherapy followed by RT for high-grade

Optic Nerve Meningioma and Gliomas

Imaging

MRI
Optic Nerve Meningioma

  • T1 hypointense
  • Calcificaiton in 30% of patients

Optic Nerve Glioma

  • T1 isointense to the cortex and hypointense orbital fat
  • T2 mixed isointense to hyperintense relative to white matter and the cortex.
  • post-T1 intense enhancement
  • Spongiform changes suggest NF1
  • Calcificaiton rare

post-T1 with fat saturaiton

Late Effects

Late Effects Causes Sign and Symptoms Onset
Optic neuropathy (radiation related) 54 Gy[2] [3] or Tumor resection • Pale optic disc
• Disc edema
• Splinter Hemorrhage
• Abnormal papillary responses
Radiation Retinopathy 45 Gy [3] • Neovascularization of retinal or nerve head
• macular edema
6 months to 3 years following RT
Neovascular Glaucoma • painful loss of vision
Cataract > 8 Gy (singel dose)
> 10-15 Gy (fractionated)
• Opaque lens
• Decreased visual acuity

Radiation tolerance of structures
lens < cornea < retina < optic nerve < choroid (sclera)

== Retinoblastoma ==

Bibliography
1. Jurgenliemk-Schulz IM, Hartman LJ, Roesink JM, Tersteeg RJ, van Der Tweel I, Kal HB, Mourits MP, Wyrdeman HK. Prevention of pterygium recurrence by postoperative single-dose beta-irradiation: a prospective randomized clinical double-blind trial. Int J Radiat Oncol Biol Phys. 2004 Jul 15;59(4):1138-47. Review. PMID: 15234049
2. Jiang GL, Tucker SL, Guttenberger R, Peters LJ, Morrison WH, Garden AS, Ha CS, Ang KK. Radiation-induced injury to the visual pathway. Radiother Oncol. 1994 Jan;30(1):17-25. PMID: 8153376
3. Parsons JT, Bova FJ, Fitzgerald CR, Mendenhall WM, Million RR. Radiation optic neuropathy after megavoltage external-beam irradiation: analysis of time-dose factors. Int J Radiat Oncol Biol Phys. 1994 Nov 15;30(4):755-63. PMID: 7960976
4. The Collaborative Ocular Melanoma Study (COMS) randomized trial of pre-enucleation radiation of large choroidal melanoma II: initial mortality findings. COMS report no. 10. Am J Ophthalmol. 1998 Jun;125(6):779-96.
PMID: 9645716
5. Hawkins BS; Collaborative Ocular Melanoma Study Group. The Collaborative Ocular Melanoma Study (COMS) randomized trial of pre-enucleation radiation of large choroidal melanoma: IV. Ten-year mortality findings and prognostic factors. COMS report number 24. Am J Ophthalmol. 2004 Dec;138(6):936-51. PMID: 15629284
6. Wiegel T, Bottke D, Kreusel KM, Schmidt S, Bornfeld N, Foerster MH, Hinkelbein W; German Cancer Society. External beam radiotherapy of choroidal metastases—final results of a prospective study of the German Cancer Society (ARO 95-08). Radiother Oncol. 2002 Jul;64(1):13-8. PMID: 12208569
7. David H. Abramson, MD, Katherine Beaverson, MS, Poorab Sangani, MD, Robin A. Vora, MD, Thomas C. Lee, MD, Hilary M. Hochberg, MD, James Kirszrot, MD and Murali Ranjithan, MD. Screening for Retinoblastoma: Presenting Signs as Prognosticators of Patient and Ocular Survival. PEDIATRICS Vol. 112 No. 6 December 2003, pp. 1248-1255
Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-Share Alike 2.5 License.