Cryopexy treatment for retinoblastoma

The role of cryotherapy in the management of retinoblastoma

Between February 1974 and August 1987, we treated 67 retinoblastomas in 47 eyes of 45 patients with cryotherapy (triple freeze-thaw technique). Overall, cryotherapy eradicated 53 (79%) of the tumors, whereas additional treatment with episcleral plaque radiotherapy, external beam radiotherapy, or enucleation was necessary in 14 (21%) of the tumors. Tumor destruction was achieved with one or more cryotherapy treatments in all cases in which the tumor was no greater than 2.5 mm in diameter and 1.0 mm in thickness, and in which the tumor was confined to the sensory retina without seeding into the adjacent vitreous humor. We therefore recommend cryotherapy in such cases. Cryotherapy alone failed in 14 larger tumors, ten of which had clinical evidence of vitreous seeding by tumor cells. Cryotherapy is therefore contraindicated in cases of vitreous seeding or if the tumor exceeds 3.5 mm in diameter and 2.0 mm in thickness. Cryotherapy can be successful for tumors up to 3.5 mm in diameter and 2.0 mm in thickness, but more than one treatment may be necessary.

Current approaches to the diagnosis and management of retinoblastoma

Retinoblastoma is the most common primary intraocular malignancy of childhood, occurring in about one out of 15,000 live births. A century ago, the mortality rate with this malignancy was nearly 100%; today, it is less than 10%. Furthermore, with recent advances in both diagnostic and therapeutic techniques, vision can often be preserved in one or both eyes. The approach to differential diagnosis utilized in the Wills Eye Hospital Ocular Oncology Service is outlined, and various diagnostic tests are described and illustrated. Procedures for examination under anesthesia are also detailed; it is emphasized that the physician should be prepared to institute appropriate treatment at the time of examination under anesthesia. Depending on the extent and nature of tumor involvement, treatment might consist of enucleation, external radiation, episcleral plaque irradiation, photocoagulation, cryotherapy, chemotherapy or a combination of these modalities. Indications, techniques and complications of each modality are discussed.

Stage-related combined modality treatment of retinoblastoma. Results of a prospective study

Forty-two consecutive patients with retinoblastoma were evaluated by a new staging system and combined modality therapy instituted according to stage. Nineteen patients had bilateral tumors and 23 had unilateral tumors. The staging system was effective in identifying subpopulations of patients and successfully predicted those at greater risk of recurrence or death. Thirty-nine of 42 patients survive (Median survival time, 42 months). Two of 4 children with tumor extension beyond the eye died while 37 of 38 children with tumor presumed confined to the eye survive. Toxicity of the chemotherapy was mild. Radiation therapy of intraocular tumor was associated with cataract formation but most children had satisfactory vision after extraction and the use of corrective lenses. Ophthalmologic findings did not always correlate with histologic extent of tumor and both should be used in planning and evaluating treatment. Recommendations are made on the role of chemotherapy and the need to reduce the morbidity of treatment.

Radiation treatment of retinoblastoma

In a series of 45 children with retinoblastoma, from the period 1953-1973, comprising 27 bilateral cases, 32 eyes were treated by irradiation. The different techniques of radiation are reviewed. In the present series small tumours were irradiated by local application of Stallard discs or Rosengren balls, while advanced cases were treated by external radiation. The results are discussed, and it is emphasized that the major factor of importance for the success of the treatment is the size of the tumour. Small tumours are cured, large ones are not. Future efforts must be directed towards early diagnosis. The treatment should be centralized in order to secure sufficient experience for the ophthalmologist and radiotherapist, as evaluation of the post- radiation fundus findings may present difficulties.

Retinoblastoma treated by freezing

Images