Treatment of retinoblastoma vitreous base seeding

Palladium-103 plaque brachytherapy for retinoblastoma: Long term follow up

Purpose

Radiation has been used in the treatment of retinoblastoma. Herein, we present the novel use of palladium-103 plaque brachytherapy as primary treatment.

Observation

An 8-year-old asymptomatic girl presented was found to have a solitary peripheral retinoblastoma in her right eye. She was treated with primary palladium-103 plaque brachytherapy (47.4 Gray over 5 consecutive days). A secondary, vitreous hemorrhage noted 46 months after irradiation was successfully controlled by laser tumor-demarcation. With 19-years follow up, there has been no clinical scleropathy, or local tumor recurrence. The eye yields 20/20 vision and there has been no systemic metastasis.

Conclusion and importance

Palladium-103 plaque brachytherapy successfully controlled retinoblastoma, while preserving the globe, vision, and life.

Vitreous relapse following primary chemotherapy for retinoblastoma: is adjuvant diode laser a risk factor?

AIMS

To evaluate rates of vitreous relapse among retinoblastoma patients treated with primary chemotherapy and assess diode laser as a potential risk factor for relapse.

METHODS

Retrospective review of all patients treated with primary chemotherapy at a large ocular oncology centre. Eyes that developed vitreous relapse were coded with regard to Reese-Ellsworth Group, laterality, time to relapse, type of relapse (vitreous base or non-vitreous base relapse), treatments used (including adjuvant diode laser), and ocular preservation. Individual tumour foci treated with laser hyperthermia were also coded for laser parameters including power settings, number of treatments, and concomitant administration of systemic chemotherapy (chemothermotherapy).

RESULTS

15 of 106 eyes (14.15%) developed vitreous relapse over a 6 year period. Mean time to relapse was 7.2 months after chemotherapy was completed. Five cases (33%) were of the vitreous base variety. Ocular salvage was attempted in 11 cases using a variety of methods; one patient was lost to follow up. Six of the remaining 10 eyes (60%) were salvaged. Eight of 38 eyes (21%) treated with systemic chemotherapy and laser hyperthermia developed vitreous relapse compared with seven of 68 eyes (10%) treated with primary chemotherapy alone (p<0.005). Laser settings, number of hyperthermia treatments, and the concomitant use of systemic chemotherapy (chemothermotherapy) were not associated with higher rates of vitreous relapse.

CONCLUSION

Nearly one in seven eyes with retinoblastoma treated with primary chemotherapy may develop vitreous relapse. The administration of diode laser hyperthermia appears to increase this risk. Despite additional therapy a number of these eyes succumb to enucleation.

Beta-ray brachytherapy with 106Ru plaques for retinoblastoma

PURPOSE

A retrospective analysis of 134 patients who received (106)Ru brachytherapy for retinoblastomas (175 tumors in 140 eyes). Treatment and follow-up were analyzed with special emphasis on tumor control organ, preservation, and late complications.

RESULTS

Treated tumors had a mean height and diameter of 3.7+/-1.4 mm and 5.0+/-2.8 disk diameters, respectively. The radiation dose values were recalculated according to the calibration standard recently introduced by the National Institute of Standards and Technology. The recalculation revealed a mean applied dose of 419 Gy at the sclera (SD, 207 Gy) and 138 Gy (SD, 67 Gy) at the tumor apex. The 5-year tumor control rate was 94.4%. Tumor recurrence was more frequent in eyes with vitreous tumor cell seeding or fish-flesh regression. The estimated 5-year eye preservation rate was 86.5%. Previous treatment by brachytherapy or external beam radiotherapy, as well as a large tumor diameter, were significant factors for enucleation. The radiotherapy-induced complications after 5 years of follow-up were retinopathy (22%), optic neuropathy (21%), and cataract (17%). These complications were significantly more frequent after prior brachytherapy or external beam radiotherapy.

CONCLUSION

Brachytherapy using (106)Ru plaques is a highly efficient therapy with excellent local tumor control and an acceptable incidence of side effects.

Continuing challenges in the management of retinoblastoma with chemotherapy

The management of retinoblastoma has gradually changed over the past 10 years. Over 95% of children with retinoblastoma in the United States are cured with modern techniques. The challenge remains, however, in maintaining the eye and vision. There is a trend away from enucleation and external beam radiotherapy toward focal conservative treatments involving primary chemoreduction in conjunction with thermotherapy and cryotherapy. This is related to earlier detection of the disease, recognition of more effective chemotherapeutic agents, more focused local treatment modalities, and, most importantly, knowledge of the long-term risks of external beam radiotherapy. Enucleation is still preferable for retinoblastoma that fills most of the eye, especially when the disease is unilateral or when there is concern for tumor invasion into the optic nerve, choroid, or orbit. The orbital integrated implant is placed after enucleation and provides acceptable prosthesis motility and appearance. External beam radiotherapy is still vital for treating advanced retinoblastoma, especially when there is diffuse vitreous or subretinal seeding after failure of other methods and preservation of vision is a priority. The most important recent advance in the management of retinoblastoma is the use of intravenous chemotherapy for tumor reduction, a technique of neoadjuvant chemotherapy termed "chemoreduction." This is followed by tumor consolidation with focal measures such as thermotherapy, cryotherapy, and plaque radiotherapy. This strategy provides reduced tumor volume and often permits consolidation with methods other than radiotherapy. It appears that vision can be preserved in some cases with these methods, avoiding some of the local complications like radiation cataract or macular edema that have been found with radiotherapy techniques. External beam radiotherapy and enucleation can now be avoided in most cases of Reese-Ellsworth groups I (minimal disease) through IV (moderate disease) retinoblastoma. The most advanced stage of retinoblastoma, Reese-Ellsworth group V, continues to provide the greatest difficulty for management, and external beam radiotherapy and enucleation are often employed in addition to chemoreduction to save the child's life. A collaborative prospective study in North America is currently under way to further study the benefits and risks of chemoreduction for minimal, moderate, and advanced retinoblastoma.

Globe conserving treatment of the only eye in bilateral retinoblastoma

AIMS

To quantify the rates of eye preservation and patient survival, local tumour relapse and recurrence, and development of new tumours in the remaining eye of children with bilateral retinoblastoma with one eye already enucleated. Also, in the same children, to describe the types of primary and secondary treatment procedures, and to define the anatomical outcome.

METHODS

This is a retrospective observational case series report. The study participants consisted of 107 patients with bilateral retinoblastoma with one eye enucleated within 1 month of baseline examination and had their remaining eye treated conservatively. The main outcome measure were: primary treatment failures, new tumours, enucleation of the only eye, death, remission, and anatomical outcomes (retinal detachment, vitreous haemorrhage, and cataract).

RESULTS

The median age at diagnosis was 8.4 (range 0.2-44, SD 10.1) months with a median ophthalmic follow up of 44.3 (8.1-114, SD 10.1) months. In 22 of the 107 patients (21%) the treated eye was in Reese Ellsworth groups I or II and in the remaining 85 (79%) in groups III-V at diagnosis. The primary treatment was cryotherapy in 14% (15/107) of eyes, radioactive plaque brachytherapy in 3.7% (4/107), and chemotherapy in 10% (11/107). It was lens sparing radiotherapy in 37% (40/107), whole eye radiotherapy in 29% (31/107), combined radiotherapy and chemotherapy in 2.8% (3/107), chemothermotherapy in 0.9% (1/107), and combined focal therapy in 1.8% (2/107). The primary treatment failed to achieve local tumour control during the follow up period in 37% (40/107) of eyes. In 17 eyes failure was due to inadequate control of the presenting tumour, in 16 to development of a new tumour, and in eight eyes to a combination of both. 35 (88%) of the 40 failures were managed by secondary conservative treatment and the remaining five were treated by enucleation of the only eye. There were eight (7.4%) deaths and the 3 year survival rate was 93% (100/108). Anatomical results included vitreous haemorrhage in four cases, tractional retinal detachment also in four cases, and 24 children required cataract surgery.

CONCLUSIONS

Aggressive conservative treatment achieved a good rate of globe salvage without impairing survival.

Efficacy of induction chemotherapy in retinoblastoma, alone or combined with other adjuvant modalities

BACKGROUND

There are not much data available on the use of newer antimetabolites as an initial treatment modality in retinoblastoma, or their effect on vitreous seedings and de novo foci, especially in the Indian subcontinent.

METHODS

To evaluate the efficacy of newer agents as induction chemotherapy, 34 tumors in 22 eyes of 19 children with bilateral retinoblastoma were treated with 2 cycles of carboplatin, etoposide, vincristine, and cyclophosphamide; each cycle was of 1 month duration. The tumor response was evaluated at 2 months and adjuvant salvage modalities (ie, cryotherapy, laser, and/or external beam radiotherapy) were added as needed. The cycles were continued and ophthalmoscopic and ultrasonographic monitorings were performed to determine further tumor response, tumor height regression, effect on vitreous seeds, and other ocular changes.

RESULTS

Mean tumor height at presentation was 4.2 mm, which regressed to 2.61 mm at 6 months (P=0.000). The biggest tumor to respond was 12.5 mm, although smaller multiple tumors regressed better. Adjuvant modalities were used in 28 tumor foci in 16 eyes. A follow up of 6 to 24 months (mean, 12.8+/-6.21 months), showed complete regression in 12/34 tumors, partial regression in 15/34, stable disease in 6/34, and 1 tumor progressed despite all therapy. Results in all 6 eyes with vitreous seeds were most gratifying; at 1 year vitreous seeds disappeared in 4 eyes and showed complete calcification in 2. Fresh new lesions were not seen in any eye with complete response after the first 2 cycles of chemotherapy. Recurrences were nil and complications minor.

CONCLUSIONS

The overall tumor response (complete and partial) of more than 80% indicates that chemoreduction is an effective modality alone and combined with adjuvant salvage modalities. The results with our treatment regime, even in cases with advanced intraocular retinoblastoma, are encouraging.

Chemoreduction and local ophthalmic therapy for intraocular retinoblastoma

PURPOSE

To study the effectiveness of combined systemic chemotherapy and local ophthalmic therapy for retinoblastoma with the goal of avoiding enucleation and external-beam radiation therapy (EBRT).

PATIENTS AND METHODS

This was a prospective, nonrandomized, single-arm clinical trial. Seventy-five eyes were followed in 47 children. Patients were treated with a six-cycle protocol of vincristine, etoposide, and carboplatin. Most (83%) also received ophthalmic treatment (cryotherapy, laser photocoagulation, thermotherapy, or plaque radiation therapy) during and/or after the chemotherapy.

RESULTS

With a median follow-up of 13 months, event-free survival was 74%, with an event defined as enucleation and/or EBRT. Six children required EBRT in seven eyes (9%); five required enucleation of one eye (7%); five required a combination of EBRT and enucleation in six eyes (8%). Reese-Ellsworth groups 1, 2, and 3 eyes had excellent results, with avoidance of EBRT or enucleation in all 39. Treatment of groups 4 and 5 was less successful, with 33% of six eyes and 53% of 30 eyes, respectively, requiring EBRT and/or enucleation. Toxicities from chemotherapy were mild and included cytopenias (89%), fever and neutropenia (28%), infection (9%), and gastrointestinal symptoms, dehydration, and vincristine neurotoxicity (40%). No patients developed a second malignancy, metastatic disease, renal disease, or ototoxicity.

CONCLUSION

In retinoblastoma patients with Reese-Ellsworth eye groups 1, 2, or 3, systemic chemotherapy used with local ophthalmic therapies can eliminate the need for enucleation or EBRT without significant systemic toxicity. More effective therapy is required for Reese-Ellsworth eye groups 4 and 5.