Management of massive orbital involvement of intraocular retinoblastoma

Update on chemotherapy modalities for retinoblastoma: Progress and challenges

Retinoblastoma stands as a paradigm of success in treating malignancies among pediatric patients. Over recent decades, the approach to managing retinoblastoma has evolved significantly, transitioning from the preservation of patients' lives to the preservation of eyes and vision while minimizing treatment-related complications. Chemotherapy, administered through diverse routes, has solidified its role as the cornerstone of retinoblastoma treatment. In addition to intravenous chemotherapy (IVC), alternative administration routes, including intraarterial (IAC), intravitreal, intracameral, and periocular delivery, have emerged as promising modalities for retinoblastoma management. Numerous studies have demonstrated outstanding outcomes, achieving nearly 100% salvage rates for eyes classified under groups A-C. However, for advanced intraocular retinoblastoma (groups D and E eyes), IAC appears to offer superior local control rates compared to IVC. Intravitreal injection of chemotherapeutic agents, when administered in a controlled and secure manner, holds promise in averting the need for enucleation and radiotherapy in advanced retinoblastoma cases presenting with vitreous seeds. The optimal chemotherapy strategy remains meticulously tailored based on numerous factors. This review provides a comprehensive update on chemotherapy across various routes, encompassing key considerations, dosages, administration methods, treatment outcomes, and potential complications. Furthermore, it explores emerging potential treatments and outlines future directions aimed at enhancing treatment outcomes.

Orbital retinoblastoma: An update

Orbital extension is a major cause of death in children with retinoblastoma in the developing countries. Delayed detection and inappropriate management contribute to poor outcome. Conventional treatment including primary orbital exenteration or chemotherapy or radiotherapy alone result in mortality as high as 70%. The recent understanding on the role of sequential multimodal therapy with a combination of high-dose chemotherapy, followed by appropriate surgery, radiotherapy, and additional adjuvant chemotherapy has helped dramatically improve life salvage.

Reconstruction of severe anophthalmic orbits and atresic eye sockets after enucleation and irradiation of retinoblastoma by vascular anastomosed free dorsalis pedis flaps' transplantation

Retinoblastoma is a common malignant intraocular tumor in childhood, and most patients require enucleation or exenteration even with irradiation. Severe anophthalmic orbits and atresic eye sockets are not rare. We conducted a retrospective study to evaluate the results of surgical management of reconstruction of severe anophthalmic orbits and atresic eye sockets with vascular anastomosed free dorsalis pedis flap transplantation. There were 5 patients (5 eyes) who underwent reconstructive surgery of severe anophthalmic orbits and atresic eye sockets after enucleation and irradiation of retinoblastoma in our hospital during the 3 years. All patients had enucleation and irradiation immediately after the retinoblastoma was diagnosed and had never worn artificial eyes because of the atresic eye sockets. Vascular anastomosed free dorsalis pedis flaps, whose dimensions were typically 6.5 × 5.5 cm(2), were transplanted to reconstruct the severe anophthalmic orbits and atresic eye sockets. The donor sites were covered by free abdominal skin flaps. All the vascular anastomosed free dorsalis pedis flaps were valid after more than 6 months of follow-up. And then all the 5 patients underwent secondary autogenous dermal fat implantation to augment the supraorbital area depression. After the 2-stage reconstruction surgery, the dimensions of the eye sockets were adequate, and all patients were able to wear their prosthesis and had a satisfactory cosmetic result. Implantation of alloplastic materials is not recommended because of insufficient blood supply of the irradiated orbital area.

Treatment and outcome of nonmetastatic extraocular retinoblastoma with a uniform chemotherapy protocol

Nonmetastatic extraocular retinoblastoma is a common entity in South-East Asia. We did a retrospective study of patients treated for isolated extraocular retinoblastoma, that is, International retinoblastoma staging system stages II and III, using a uniform chemotherapy protocol at our oncology center, between June 2003 and June 2008. Out of the 25 patients having nonmetastatic extraocular retinoblastoma, 6 were in stage II, and 19 in stage III. The probability of event-free survival was 0.54 at 18 months of follow-up with no significant difference between the 2 stages and the presence of optic nerve involvement; 11 out of 13 relapses were systemic. This is the largest case series of nonmetastatic extraocular retinoblastoma from South-East Asia.

The addition of ifosfamide/etoposide to cisplatin/teniposide improves the survival of children with retinoblastoma and orbital involvement

This study aimed to determine the impact of the addition of ifosfamide/etoposide to a regimen containing cisplatin/teniposide on the survival of patients with retinoblastoma with orbital involvement. Thirty patients were treated at the A. C. Camargo Hospital, Brazil, from 1986 to 2002. From 1986 to April 1992 (period I, n=12), treatment consisted of 3 cycles of induction chemotherapy with cisplatin and teniposide, followed by maintenance with same drugs alternating with cyclophosphamide, vincristine, and doxorubicin every 21 days for 60 weeks. Since April 1992 (period II, n=18), the treatment consisted of 3 cycles of ifosfamide and etoposide followed by maintenance with same drugs, alternating with cisplatin and teniposide every 21 days for 36 weeks. In both periods, children were submitted to exenteration with eyelid preservation and orbital radiation therapy with 45 cGy, and also received intrathecal therapy with methotrexate plus dexamethasone and cytarabine. Kaplan-Meier method was used for survival analysis. The median age was 31 months. Most patients (86.7%) presented unilateral tumors. The 3-year overall survival was 34.4% and 72.2%, respectively, for patients treated during periods I and II (P=0.061). The addition of ifosfamide/etoposide to chemotherapy with cisplatin/teniposide improves survival in these patients, but further studies are still necessary.

Interactions of carboplatin with fibrin(ogen), implications for local slow release chemotherapy

The effect of carboplatin (CPt) on fibrin(ogen) clot formation and the possible use of this combination for local slow release chemotherapy were examined. CPt significantly reduced thrombin-induced fibrin clotting time (CT) and increased clot turbidity in a concentration-dependent manner. When CPt was mixed with physiological levels of fibrinogen (>1 mg/ml), electron-dense nanoparticles (3 nm) were formed, as demonstrated by both optical particle counter and transmission electron microscopy (TEM). Upon thrombin-induced coagulation, the CPt nanoparticles were trapped within the fibrin mesh. At higher fibrinogen levels (>5 mg/ml), the 3-nm CPt nanoparticles aggregated, so that approximately 2% and approximately 0.5% of the CPt on the fibrinogen appeared as larger particles of 10 and 50 nm, respectively. Dialysis experiments showed that 60-70% of the CPt was released from the fibrin clot within one hour as a non-particulate soluble form, while approximately 30% of particulate CPt were retained. Up to 5 mg/ml this portion of firmly attached CPt was dependent of the initial drug level. CPt released from the fibrin by either diffusion or by fibrinolysis exhibited cytotoxic activity towards retinoblastoma (RB) cell lines (Y-79 and Weri RB1) equivalent to free drug. Our study indicates that CPt enhances fibrin clot formation and suggests the use of fibrin with high dose CPt for slow release chemotherapy against localized tumors such as retinoblastoma.

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.

Treatment of overt extraocular retinoblastoma

BACKGROUND

Overt extraocular retinoblastoma is common in developing countries and little information about its treatment is available. The aim of this study is to report our experience in the treatment of these cases using a uniform approach.

PROCEDURE

Patients with overt extraocular retinoblastoma including orbital extension, preauricular lymph node invasion and/or metastatic disease on diagnosis or after extraocular relapse admitted to the Hospital JP Garrahan from August 1987 to December 2000 were retrospectively reviewed. Patients were treated according to two different protocols (1987-1993 and 1994-2000). Treatment included: neoadjuvant combination chemotherapy followed by limited surgery in case of orbital extension (enucleation or resection of residual orbital mass) and adjuvant chemotherapy and radiotherapy. Chemotherapy included cyclophosphamide, vincristine, etoposide, doxorubicin (in protocol 87), idarubicin (in protocol 94), cisplatin (in protocol 87), and carboplatin (in protocol 94).

RESULTS

Forty-one patients were included. Fifteen of them had orbital or preauricular disease and had a 5-year event-free survival (pEFS) of 84%. Twenty-six had distant metastatic disease and non survived 5-years. One patient died of toxicity and one died in complete remission. One patient had a secondary leukemia. The remaining adverse events included CNS and/or systemic relapse.

CONCLUSIONS

This treatment strategy was highly efficacious for patients with orbital and/or lymph node extension. Orbital exenteration is not necessary for these patients. Those patients with distant metastatic or CNS disease were not curable with this approach.

Postenucleation orbits in retinoblastoma: treatment with 125I brachytherapy

PURPOSE

Children with retinoblastoma that extends into or through the choroid, sclera, or optic nerve are at risk of developing orbital disease, as well as metastases. Previously, these enucleated orbits were treated with external beam radiotherapy in addition to chemotherapy. 125I brachytherapy for tumors in and around the eye was pioneered by Sealy in Cape Town, South Africa, in 1974. In 1983, he developed a technique to irradiate the contents of the orbit while limiting the dose to the bony orbit and eyelids.

METHODS AND MATERIALS

Six nylon tubes containing 125I seeds were implanted through the eyelids around the periphery of the orbit. Each contained a metal gutter that screens the outer part of the seeds from the bony orbit. A seventh unscreened tube was placed in the center, and a metal disc with 125I seeds on its posterior surface was secured beneath the eyelids. Between 1983 and 2000, 57 orbits were treated in 56 children with retinoblastoma. Thirty-six were treated prophylactically and 21, with tumor at the resection line of the nerve, extrascleral tumor, or metastases, were treated therapeutically. They received a median dose of 34 Gy in 70 h; 30 also received chemotherapy. Children with tumor at the resection line of the nerve also received treatment to the craniospinal axis.

RESULTS

The median follow-up of the 35 patients treated prophylactically was 35 months (range 0-187). Seven patients died, 6 of metastases, at a median of 10 months (range 4-29) after the implant. Eight of the 13 patients with microscopic extraocular tumor survived a median of 29 months (range 5-156). None of the 8 patients presenting with orbital tumor or metastases survived. No orbital recurrences developed in any of the patients. Cosmesis was considerably improved compared with previous forms of irradiation.

CONCLUSION

Orbital brachytherapy is an effective method of irradiating the orbit to prevent recurrent tumor, the treatment time is short, and the cosmesis is much more acceptable than with other forms of irradiation. No facial atrophy or second nonocular tumors have occurred.

Risk factors for metastasis in retinoblastoma

Children with retinoblastoma typically survive their cancer due to advances in early diagnosis and treatment. Despite this success, risk factors persist for metastasis that are thought to be related to patient age, sex, laterality, treatment, genetics, histopathology, and extraocular extension. This review has found that invasion of the uvea, orbit, and optic nerve continue to be the most important predictors of metastatic retinoblastoma. Bilaterality and delays in diagnosis are also important factors. We examine molecular and genetic studies that offer the potential of predicting which tumors are likely to metastasize, which will recur within the eye, and which will undergo senescence. In this review, we describe which clinical evaluations, genetic studies, and histopathologic evaluations of retrieved specimens are currently used widely. This review has been performed to help those caring for patients with retinoblastoma and to aid informed consent.

Vitrectomy in eyes with unsuspected retinoblastoma

OBJECTIVE

To analyze patient management and prognosis after vitrectomy in eyes with unsuspected retinoblastoma.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

Eleven consecutive patients who had undergone vitrectomy on an eye with unsuspected retinoblastoma.

MAIN OUTCOME MEASURES

The two main outcome measures were ultimate patient management and the development of retinoblastoma metastasis.

RESULTS

Of more than 900 consecutive patients with retinoblastoma managed on the Ocular Oncology Service at Wills Eye Hospital in Philadelphia, 11 (1%) had prior vitrectomy in an eye with viable tumor before referral to us for suspected retinoblastoma. The main preoperative diagnoses included vitreous hemorrhage in seven patients (64%), toxocariasis in two patients (18%), toxoplasmosis in one patient (9%), and endophthalmitis in one patient (9%). In no case was retinoblastoma suspected before vitrectomy. The mean patient age at vitrectomy was 6 years. Retinoblastoma was later suspected during vitrectomy in two patients (18%), on cytologic examination of the vitrectomy specimen in eight patients (73%), and after referral in one patient (9%). The mean interval between vitrectomy and referral to us was 23 days. On examination, the globe was classified as Reese-Ellsworth group Vb in all 11 patients (100%). Anterior chamber tumor cells were clinically visible in four eyes (36%), hyphema in two eyes (18%), and iris neovascularization in two eyes (18%). Retinoblastoma cells were visualized in the vitreous in seven eyes (64%) and not visualized in four eyes (36%) that had vitreous blood. Enucleation was necessary in all 11 patients (100%). Adjuvant treatment was delivered in 10 patients (91%), using orbital radiotherapy in nine patients (82%) and chemotherapy in nine patients (82%). Histopathologic evidence of retinoblastoma invasion was documented in the episclera (two eyes; 18%), anterior chamber (seven eyes; 64%), iris (five eyes; 45%), ciliary body (five eyes; 45%), choroid (three eyes; 27%), and optic nerve (four eyes; 36%; prelaminar, two eyes; postlaminar, two eyes). The vitrectomy ports, Tenon's fascia, cut end of the optic nerve, and orbit were free of tumor. Of the 10 patients who received prophylactic chemotherapy, radiotherapy, or both in addition to enucleation for prevention of retinoblastoma metastasis, none (0%) experienced metastasis or orbital recurrence during the mean follow-up of 7 years (range, 0.2-24 years) from the time of retinoblastoma diagnosis. However, one patient was referred to us after the development of metastatic retinoblastoma, and despite aggressive chemotherapy and radiotherapy after enucleation, died 24 months later.

CONCLUSIONS

Retinoblastoma may present with atypical features such as vitreous hemorrhage or signs of vitreous inflammation, particularly in older children. Vitrectomy should be avoided in these cases until the possibility of underlying retinoblastoma is excluded. If vitrectomy is performed in an eye with unsuspected retinoblastoma, enucleation combined with adjuvant chemotherapy, radiotherapy, or both without delay is advised to prevent systemic tumor dissemination.

Successful treatment of metastatic retinoblastoma

BACKGROUND

In the past, patients with metastatic retinoblastoma have had a poor prognosis when treated with conventional modalities. In the current study, the authors evaluated the use of combined intensive conventional chemotherapy, high dose chemotherapy with autologous stem cell rescue (ASCR), and radiation therapy.

METHODS

Four patients with metastatic retinoblastoma were treated. All had orbital and bone marrow metastases. In addition, three patients had bone metastases and two patients had liver metastases. None had central nervous system disease. Patients received intensive conventional chemotherapy that included vincristine, cyclophosphamide, etoposide, and either cisplatin or carboplatin. Stem cells were harvested after bone marrow disease was no longer detectable. High dose chemotherapy with carboplatin (500 mg/m(2)/day x 3 days or area under the curve = 7 via the Calvert formula) and thiotepa (300 mg/m(2)/day x 3 days) with (n = 3 patients) or without (n = 1 patient) etoposide (250 mg/m(2)/day x 3 days) was administered with ASCR. Sites that originally harbored bulky disease were irradiated after recovery from the high dose chemotherapy.

RESULTS

The therapy was associated with substantial acute hematopoietic and mucosal toxicities. At last follow-up, all four patients had survived event free from 46-80 months after the diagnosis of metastatic disease.

CONCLUSIONS

The treatment strategy described in the current study is effective for patients with metastatic retinoblastoma that does not involve the central nervous system. However, a multicenter trial should be considered to evaluate it in a larger group of patients.

Recent developments in the management of retinoblastoma

The management of retinoblastoma has gradually changed over the past few decades. There is a trend away from enucleation and external beam radiotherapy toward focal conservative treatments. This is primarily because of earlier detection of the disease and more focused treatment modalities. Enucleation is still employed for retinoblastoma that fills most of the eye, especially when there is a concern for tumor invasion into the optic nerve or choroid. After enucleation, an integrated orbital implant, provides improved motility and appearance of the prosthesis. External beam radiotherapy continues to be an important method of treating less advanced retinoblastoma, especially when there is diffuse vitreous or subretinal seeding. Plaque radiotherapy is useful for controlling small- to medium-sized retinoblastomas, even those with focal vitreous seeds. Tumors that recur after failure of other methods are often suitable for plaque treatment. When plaque radiotherapy is employed in a child receiving chemotherapy, eventual radiation retinopathy can occur. Cryotherapy and photocoagulation provide excellent control of selected small tumors. Advanced laser delivery systems, particularly those that have been adapted to the indirect ophthalmoscope, have facilitated the visualization for treatment of tumors. Thermotherapy is the newest focal method for retinoblastoma. When combined with chemotherapy, thermotherapy provides satisfactory tumor control, leaving the child with a reasonably small scar, thus preserving more vision. Chemoreduction, using intravenous or subconjunctival routes, is often employed to reduce initial tumor volume and thus allow for focal treatment to eradicate the residual smaller tumor. Many children with advanced retinoblastoma can be spared external beam radiotherapy and enucleation mostly as a result of chemoreduction and focal methods. Chemoreduction combined with cryotherapy, thermotherapy, and plaque radiotherapy plays an important role in the current management of many children with retinoblastoma.

Visualization of orbital retinoblastoma with technetium-99m (V) dimercaptosuccinic acid

The potential contributions of technetium-99m (V) dimercaptosuccinic acid scintigraphy in the evaluation of orbital retinoblastoma, its local extensions and metastases were assessed in this study. Both planar and SPECT images clearly demonstrated the primary tumor and metastatic sites. Following confirmation of our results by contemporaneous ultrasonography, MRI and a subsequent incisional biopsy, the patient was treated with external beam radiotherapy and chemotherapy. This preliminary study showed that in combination with other diagnostic tests, Tc-99m (V) DMSA scintigraphy may play a role in the detection and follow-up of the local tumor extensions and metastases in patients with retinoblastoma.