The role of cryotherapy in the management of retinoblastoma

Advanced Interventional Treatments in Retinoblastoma Management: A Comprehensive Review

Retinoblastoma is the most common eye malignancy in children that if left untreated can invade intraocular structures, metastasize, and rarely lead to death. Traditionally treated with systemic chemotherapy, Intra-arterial chemotherapy is gaining popularity as it allows for the direct administration of chemotherapy through the ophthalmic artery, thus reducing systemic side effects. Intra-arterial chemotherapy procedures have evolved, with refinements to reduce risks and radiation exposure. Intra-arterial chemotherapy boasts an impressive technical success rate and one year ocular survival even amongst advanced cases. This review offers a thorough examination of the technique, indications, contraindications, outcomes, and alternative options for Intra-arterial chemotherapy.

Advancements in the diagnosis, prognosis, and treatment of retinoblastoma

Retinoblastoma (RB) is a prevalent primitive intraocular malignancy in children, particularly in those younger than age 3 years. RB is caused by mutations in the RB1 gene. In developing countries, mortality rates for this type of cancer are still high, whereas industrialized countries have achieved a survival rate of >95%-98%. Untreated, the condition can be fatal, underscoring the importance of early diagnosis. The existing treatments primarily consist of surgery, radiotherapy, and chemotherapy. The detrimental effects of radiation and chemotherapeutic drugs have been documented as factors that contribute to increased mortality rates and negatively affect the quality of life for patients. MicroRNA (miRNA), a type of noncoding RNA, exerts a substantial influence on RB development and the emergence of treatment resistance by regulating diverse cellular processes. This review highlights recent developments in the involvement of miRNAs in RB. This encompasses the clinical significance of miRNAs in the diagnosis, prognosis, and treatment of RB. Additionally, this paper examines the regulatory mechanisms of miRNAs in RB and explores potential therapeutic interventions. This paper provides an overview of the current and emerging treatment options for RB, focusing on recent studies investigating the application of different types of nanoparticles for the diagnosis and treatment of this condition.

Nanoparticle-based delivery systems as emerging therapy in retinoblastoma: recent advances, challenges and prospects

Retinoblastoma is the most common intraocular malignancy in children. The treatment of this rare disease is still challenging in developing countries due to delayed diagnosis. The current therapies comprise mainly surgery, radiotherapy and chemotherapy. The adverse effects of radiation and chemotherapeutic drugs have been reported to contribute to the high mortality rate and affect patients' quality of life. The systemic side effects resulting from the distribution of chemotherapeutic drugs to non-cancerous cells are enormous and have been recognized as one of the reasons why most potent anticancer compounds fail in clinical trials. Nanoparticulate delivery systems have the potential to revolutionize cancer treatment by offering targeted delivery, enhanced penetration and retention effects, increased bioavailability, and an improved toxicity profile. Notwithstanding the plethora of evidence on the beneficial effects of nanoparticles in retinoblastoma, the clinical translation of this carrier is yet to be given the needed attention. This paper reviews the current and emerging treatment options for retinoblastoma, with emphasis on recent investigations on the use of various classes of nanoparticles in diagnosing and treating retinoblastoma. It also presents the use of ligand-conjugated and smart nanoparticles in the active targeting of anticancer and imaging agents to the tumour cells. In addition, this review discusses the prospects and challenges in translating this nanocarrier into clinical use for retinoblastoma therapy. This review may provide new insight for formulation scientists to explore in order to facilitate the development of more effective and safer medicines for children suffering from retinoblastoma.

Retinoblastoma: present scenario and future challenges

With an average incidence of 1 in every 18,000 live births, retinoblastoma is a rare type of intraocular tumour found to affect patients during their early childhood. It is curable if diagnosed at earlier stages but can become life-threateningly malignant if not treated timely. With no racial or gender predisposition, or even environmental factors known to have been involved in the incidence of the disease, retinoblastoma is often considered a clinical success story in pediatric oncology. The survival rate in highly developed countries is higher than 95% and they have achieved this because of the advancement in the development of diagnostics and treatment techniques. This includes developing the already existing techniques like chemotherapy and embarking on new strategies like enucleation, thermotherapy, cryotherapy, etc. Early diagnosis, studies on the etiopathogenesis and genetics of the disease are the need of the hour for improving the survival rates. According to the Knudson hypothesis, also known as the two hit hypothesis, two hits on the retinoblastoma susceptibility (RB) gene is often considered as the initiating event in the development of the disease. Studies on the molecular basis of the disease have also led to deciphering the downstream events and thus in the discovery of biomarkers and related targeted therapies. Furthermore, improvements in molecular biology techniques enhanced the development of efficient methods for early diagnosis, genetic counseling, and prevention of the disease. In this review, we discuss the genetic and molecular features of retinoblastoma with a special emphasis on the mutation leading to the dysregulation of key signaling pathways involved in cell proliferation, DNA repair, and cellular plasticity. Also, we describe the classification, clinical and epidemiological relevance of the disease, with an emphasis on both the traditional and innovative treatments to tackle retinoblastoma. Video Abstract.

Advances in the treatment of intraocular malignancies: A literature review

Intraocular malignant tumors including primary and metastatic tumors, are mainly found in Retina and uvea, and very few cases originate from the sclera and optic nerve. Intraocular tumors can endanger the patient's vision and even life, and proper treatment is vital. There have been several traditional treatments for intraocular tumors, such as radiotherapy, chemotherapy and surgery. In recent years, new methods have been developed in clinical applications including anti-VEGF and gene therapy. This paper aims to provide a timely review about recent progress in the treatment of intraocular malignant tumor.

Advances in biomaterials for the treatment of retinoblastoma

Retinoblastoma is the most common primary intraocular malignancy in children. Although traditional chemotherapy has shown some success in retinoblastoma management, there are several shortcomings to this approach, including inadequate pharmacokinetic parameters, multidrug resistance, low therapeutic efficiency, nonspecific targeting, and the need for adjuvant therapy, among others. The revolutionary developments in biomaterials for drug delivery have enabled breakthroughs in cancer management. Today, biomaterials are playing a crucial role in developing more efficacious retinoblastoma treatments. The key goal in the evolution of drug delivery biomaterials for retinoblastoma therapy is to resolve delivery-associated obstacles and lower nonlocal exposure while ameliorating certain adverse effects. In this review, we will first delve into the historical perspective of retinoblastoma with a focus on the classical treatments currently used in clinics to enhance patients' quality of life and survival rate. As we move along, we will discuss biomaterials for drug delivery applications. Various aspects of biomaterials for drug delivery will be dissected, including their features and recent advances. In accordance with the current advances in biomaterials, we will deliver a synopsis on the novel chemotherapeutic drug delivery strategies and evaluate these approaches to gain new insights into retinoblastoma treatment.

The Role of Cryotherapy in Vitreous Concentrations of Topotecan Delivered by Episcleral Hydrogel Implant

Transscleral diffusion delivery of chemotherapy is a promising way to reach the vitreal seeds of retinoblastoma, the most common intraocular malignancy in childhood. In this in vivo study, the delivery of topotecan via lens-shaped, bi-layered hydrogel implants was combined with transconjunctival cryotherapy to assess whether cryotherapy leads to higher concentrations of topotecan in the vitreous. The study included 18 New Zealand albino rabbits; nine rabbits received a topotecan-loaded implant episclerally and another nine rabbits received transconjunctival cryotherapy superotemporally 2 weeks before implant administration. Median vitreous total topotecan exposures (area under the curve, AUC) were 455 ng·h/mL for the cryotherapy group and 281 ng·h/mL for the non-cryotherapy group, and were significantly higher in the cryotherapy group, similar to maximum levels. Median plasma AUC were 50 ng·h/mL and 34 ng·h/mL for the cryotherapy and non-cryotherapy groups, respectively, with no statistically significant differences between them. In both groups, AUC values in the vitreous were significantly higher than in plasma, with plasma exposure at only approximately 11–12% of the level of vitreous exposure. The results confirmed the important role of the choroidal vessels in the pharmacokinetics of topotecan during transscleral administration and showed a positive effect of cryotherapy on intravitreal penetration, resulting in a significantly higher total exposure in the vitreous.

Racial, Ethnic, and Socioeconomic Disparities in Retinoblastoma Enucleation: A Population-Based Study, SEER 18 2000-2014

PURPOSE

To determine the effect of race, ethnicity, and census tract-level composite socioeconomic status (SES) on retinoblastoma enucleation. This study augments Truong and associates, providing multivariate analyses combining sociodemographic and clinical characteristics with more accurate SES measures. We hypothesized that children from nonwhite, Hispanic, and lower socioeconomic backgrounds would have increased adjusted odds of enucleation.

DESIGN

Retrospective cohort analysis.

SETTING

Multicenter population-based study using the Surveillance, Epidemiology, and End Results (SEER) 18 Registries.

STUDY POPULATION

Children aged 18 years and younger diagnosed with retinoblastoma between 2000 and 2014. Subjects were identified using International Classification of Diseases-Oncology (ICD-O) site and morphology codes.

MAIN OUTCOME MEASURES

Enucleation odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Analysis of 959 retinoblastoma patients revealed that 70.8% were enucleated. Adjusted analyses showed associations between enucleation and Asian (OR 2.00, CI 1.08-3.71) or black (2.42, 1.41-4.16) race, Hispanic ethnicity (1.69, 1.16-2.46), and low SES (1.68, 1.09-2.58). Significantly increased enucleation risk was associated with older age at diagnosis (age 1-2 years 2.55, 1.80-3.61; >2 years 4.88, 2.57-9.25), unilateral disease (5.00, 3.45-7.14), and advanced stage (regional 4.71, 2.51-8.84; distant 3.15, 1.63-6.08). No interactions were observed between race, ethnicity, SES, and stage at diagnosis. Enucleation rates decreased over time across all racial, ethnic, and socioeconomic groups.

CONCLUSIONS

Children from nonwhite, Hispanic, and lower socioeconomic backgrounds are more likely to receive enucleation. These associations are independent of stage of diagnosis, suggesting larger systemic disparities in retinoblastoma care. The origin of these differences requires further study and attention by clinicians and policy makers.

Options for management of intra ocular tumors

The management of intra ocular tumors has undergone a sea change from the era of enucleation or external beam radiation. With the advent of new chemotherapy protocols, globe and vision salvage have become possible in a majority of cases of retinoblastoma. This article is an overview of the various modalities available for the management of intra ocular tumors and their indications. Chemotherapy has been covered elsewhere in this series of articles on ocular oncology. Photocoagulation and cryopexy are easily administered modalities of treatment for small tumors and totally within the ophthalmologist's domain. Slightly larger tumors are treatable with brachytherapy. The susceptibility of the tumors to chemotherapy and radiation decide the choice of treatment and the dosage. Management of intra ocular tumors very often needs a multidisciplinary approach including ophthalmologist, oncologist, radiation physicist, and radiotherapist.

Retinoblastoma

Retinoblastoma is the most common neoplasm of the eye in childhood, and represents 3% of all childhood malignancies. Retinoblastoma is a cancer of the very young; two-thirds are diagnosed before 2 years of age and 95% before 5 years. Retinoblastoma presents in 2 distinct clinical forms: (1) a bilateral or multifocal, heritable form (25% of all cases), characterized by the presence of germline mutations of the RB1 gene; and (2) a unilateral or unifocal form (75% of all cases), 90% of which are nonhereditary. The treatment of retinoblastoma is multidisciplinary and is designed primarily to save life and preserve vision.

Conservative treatment modalities in retinoblastoma

Retinoblastoma is the most common primary intraocular malignancy of childhood. A potentially curable cancer, its treatment has improved significantly over the last few decades. The purpose of this article is to review the literature on various conservative treatment modalities available for the treatment of retinoblastoma and their effectiveness, when used alone or in combination. Pubmed, Medline, Embase, and the Cochrane library were searched through 2012 for published peer reviewed data on conservative treatment modalities for retinoblastoma. Various studies show that while enucleation remains the standard of care for advanced intraocular tumors, conservative modalities that can result in globe salvage and preservation of useful vision are being increasingly employed. Such modalities include systemic chemotherapy, focal consolidation with transpupillary thermotherapy, laser photocoagulation and cryotherapy, plaque brachytherapy, and delivery of local chemotherapy using subconjunctival, sub-tenon, or intra-arterial routes. When used alone or in combination, these treatment modalities can help in avoidance of external beam radiotherapy or enucleation, thus reducing the potential for long-term side effects, while salvaging useful vision. Radioactive plaque brachytherapy has an established role in selected patients with intraocular retinoblastoma. Local injections of chemotherapeutic agents via the sub-tenon or sub-conjunctival route have been used with varying degrees of success, usually as an adjunct to systemic chemotherapy. Intra-arterial ophthalmic artery delivery of melphalan has shown promising results. It is important to recognize that today, several treatment options are available that can obviate the need for enucleation, and cure the cancer with preservation of functional vision. A thorough knowledge and understanding of these conservative treatment modalities is essential for appropriate management.

Retinoblastoma: an overview

Retinoblastoma, the most common intraocular malignancy of childhood arises due to mutation of the retinoblastoma gene on chromosome 13q14. In the hereditary setting this mutation is present in all germ line cells and can occur as early as during development; however it requires a mandatory second "hit" or mutation of the remaining allele for retinoblastoma to develop. The non-hereditary form arises from spontaneous mutation affecting both alleles in a somatic cell of the retina. The tumor may present with leucocoria or strabismus. The diagnosis is best made by an ophthalmologist who examines the patient under sedation. Although tissue biopsy is not routinely performed, imaging studies like ultrasound and MRI scan can serve as useful adjuncts to help in establishing the diagnosis and also aid in staging. Group A tumors are smaller than 3 mm while group B tumors are >3 mm or those located in the macula. Groups C and D tumors are associated with localized and diffuse vitreous seeds respectively. Group E tumors occupy >50% of the globe and are generally not salvagable. Despite the fact that great advances have been made in the treatment of retinoblastoma in the last two decades, a large number patients undergo procedures associated with significant morbidity such as enucleation. We recommend large multi institutional studies using newer therapeutic models and targeting novel pathways to improve the outcome in advanced stage retinoblastoma.

Dosimetric study of current treatment options for radiotherapy in retinoblastoma

PURPOSE

To determine the best treatment technique for patients with retinoblastoma requiring radiotherapy to the whole eye.

METHODS AND MATERIALS

Treatment plans for 3 patients with retinoblastoma were developed using 10 radiotherapy techniques including electron beams, photon beam wedge pair (WP), photon beam three-dimensional conformal radiotherapy (3D-CRT), fixed gantry intensity-modulated radiotherapy (IMRT), photon volumetric arc therapy (VMAT), fractionated stereotactic radiotherapy, and helical tomotherapy (HT). Dose-volume analyses were carried out for each technique.

RESULTS

All techniques provided similar target coverage; conformity was highest for VMAT, nine-field (9F) IMRT, and HT (conformity index [CI] = 1.3) and lowest for the WP and two electron techniques (CI = 1.8). The electron techniques had the highest planning target volume dose gradient (131% of maximum dose received [D(max)]), and the CRT techniques had the lowest (103% D(max)) gradient. The volume receiving at least 20 Gy (V(20Gy)) for the ipsilateral bony orbit was lowest for the VMAT and HT techniques (56%) and highest for the CRT techniques (90%). Generally, the electron beam techniques were superior in terms of brain sparing and delivered approximately one-third of the integral dose of the photon techniques.

CONCLUSIONS

Inverse planned image-guided radiotherapy delivered using HT or VMAT gives better conformity index, improved orbital bone and brain sparing, and a lower integral dose than other techniques.

Consideraciones clínicas, diagnósticas y de tratamiento en retinoblastoma

El  retinoblastoma es el  tumor  intraocular  primario más frecuente en la infancia. Su detección temprana y el inicio del tratamiento adecuado permiten mejorar  dramáticamente la sobrevida en estos niños. En este artículo se hace una revisión general de la enfermedad. Se empleó PubMed y se revisaron artículos representativos del tema, que permitieran dar una idea general de los diferentes avances alcanzados. Dada su clínica característica, el médico de atención primaria, es pieza fundamental en la captación inicial del paciente.

Stereotactic radiotherapy as an alternative to plaque brachytherapy in retinoblastoma

Radioactive plaque brachytherapy has an established role for selected patients with retinoblastoma. Newer non-invasive radiotherapy techniques such as stereotactic conformal radiotherapy (SCR) that uses highly accurate positioning to deliver treatment with small beams may be an interesting alternative to brachytherapy. We report a case treated with SCR and compare the dosimetry with that achievable with brachytherapy. With advantages and disadvantages to both, SCR should more often be considered in the management of RB because of the more homogeneous dose within the target volume and similar or lower doses to surrounding normal tissues.

Rhegmatogenous retinal detachment following treatment for retinoblastoma

PURPOSE

To elucidate characteristics of rhegmatogenous retinal detachment that developed in children who underwent treatment for retinoblastoma and to analyze the outcome following vitreoretinal surgery in such clinical settings.

METHODS

This was a retrospective case series of 9 eyes of 9 patients who underwent vitreoretinal surgery for tumor control and retinal reattachment.

RESULTS

At the time of diagnosis of rhegmatogenous retinal detachment, retinoblastoma was regressed in 6 eyes (67%). The retinal detachment involved less than two quadrants in 7 eyes (78%) and was caused by an atrophic break in 7 eyes. Seven eyes underwent a non-drainage scleral buckling procedure. Three eyes underwent vitreous surgery; in 2 of these eyes, tumor excision along with retinectomy using melphalan infusion was performed and eventually silicone oil tamponade was used. Retinal reattachment was achieved in all eyes with eventual tumor control in 7 eyes. The median follow-up after retinal reattachment surgery was 24 months.

CONCLUSION

Rhegmatogenous retinal detachment in treated eyes with retinoblastoma is usually caused by an atrophic retinal break. Retinal detachment can be repaired successfully in most eyes.

Appearance and Spontaneous Resolution of Macular Pucker After Triple Freeze-Thaw Cryotherapy for Retinoblastoma

This report describes a case of macular pucker after triple freeze-thaw cryotherapy for retinoblastoma. Seven months after cryotherapy, the macular pucker resolved spontaneously.

Diagnosis and management of retinoblastoma

BACKGROUND

Retinoblastoma is a highly malignant tumor of the eye that manifests most often in the first 3 years of life.

METHODS

Published articles were reviewed to evaluate the clinical features and current methods of diagnosis and to assess the trends in management.

RESULTS

This malignancy leads to metastatic disease and death in 50% of children worldwide but in less than 5% of children in the United States and other developed nations with advanced medical care. Over the past decade, there has been a trend away from enucleation and external beam radiotherapy and toward chemoreduction followed by focal therapies. This is largely due to more effective chemotherapeutic regimens, improved focal treatment modalities, and the desire to avoid loss of the globe and/or exposure to radiotherapy. Chemoreduction and focal therapies are most successful for eyes with minimal to moderate retinoblastoma, with enucleation needed in less than 15% of cases. Eyes with very advanced retinoblastoma require enucleation in approximately 50% of cases.

CONCLUSIONS

Progress in the clinical recognition and management of retinoblastoma has led to high survival rates. Improved methods of treatment using chemoreduction and focal treatments without the need for external beam radiotherapy allow preservation of the eye in some cases, often with visual function.

Retinoblastoma—comparative analysis of external radiotherapy techniques, including an IMRT technique

PURPOSE

To compare the numerous external radiotherapy (RT) techniques for the treatment of retinoblastoma, as well as an intensity-modulated RT (IMRT) technique. The latter was elaborated to evaluate the potential dose reduction in the surrounding tissue, as well as the potential avoidance of subdosage in the ora serrata retinae.

METHODS AND MATERIALS

A 2-year-old patient with unilateral retinoblastoma underwent CT. With the aid of an ophthalmologist, the ocular structures were delimited, and 13 techniques described in published reports were reproduced on three-dimensional planning software and identified according to their authors. A technique with four noncoplanar fields using IMRT was also elaborated. These techniques were compared according to the dose to the ora serrata retinae, lens, orbit (volume that received a dose of >or=20 Gy), vitreous, optic nerve, lacrimal gland (volume that received a dose of >or=34 Gy), and cornea and according to their ease of reproducibility.

RESULTS

The techniques that attained the therapeutic dose to the ora serrata retinae were the IMRT technique and the techniques of Haye, Cassady, Cormack, and al-Beteri. The Cormack technique had the lowest volume that received a dose of >or=20 Gy in the orbit, followed by the IMRT technique. The IMRT technique also achieved the lowest volume that received a dose of >or=34 Gy (14%) in the lacrimal gland. The Abramson/McCormick/Blach, Cassady, Reese, and Schipper techniques were the easiest to reproduce and the Chin the most complex.

CONCLUSION

Retinoblastoma treatment with IMRT has an advantage over the other techniques, because it allows for the greatest reduction of dose to the orbit and lacrimal gland, while maintaining the therapeutic dose to the ora serrata retinae and vitreous.

Beta-Ray Brachytherapy of Retinoblastoma: Feasibility of a New Small-Sized Ruthenium-106 Plaque

A non-comparative case observation study estimated the feasibility of brachytherapy for retinoblastoma with a newly designed ruthenium-106 plaque (label: CXS) with an 8-mm diameter of the irradiation zone.

METHODS

The new CXS plaque was used between 2001 and 2003 for brachytherapy of 13 retinoblastomas. Indications were recurrences after preceding local treatment or endophytic retinoblastoma with an impending vitreous tumour cell seeding. The prescribed radiation dose at the apex was 88 Gy (NIST-calibrated dosimetry).

RESULTS

The mean age at brachytherapy was 1.2 years (standard deviation, SD: 1.1 years), and the mean follow-up was 1.7 years (SD: 0.6 years). The treated tumours had a mean diameter of 2.3 mm (SD: 0.7 mm) and a mean height of 1.5 mm (SD: 0.6 mm) with a mean distance to the optic disc of 9.9 mm (SD: 2.2 mm). The mean duration of irradiation was 29.3 h (SD: 9.9 h) with a mean dose at the sclera of 213 Gy (SD: 80 Gy). Surgery was uneventful in all cases. Complete regression developed after 3.1 months (SD: 2.8 months) in all cases without a recurrence or a progression of the vitreous tumour cell seeding. The eyes developed no further side-effects besides a temporary circumscribed intra-ocular haemorrhage that emerged from the regressive tumour remnants.

CONCLUSION

Brachytherapy with the CXS plaque seems to be a safe and reliable treatment option for small-sized retinoblastoma when laser or cryocoagulation failed to control the tumour growth or for small retinoblastoma with an incipient local tumour cell seeding on the tumour surface.

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.

Chemoreduction for retinoblastoma. Analysis of tumor control and risks for recurrence in 457 tumors

PURPOSE

To evaluate retinoblastoma control following chemoreduction.

DESIGN

Interventional case series.

METHODS

Prospective.

SETTING

Single center trial.

PATIENT POPULATION

457 retinoblastomas in 193 eyes of 125 patients. Nonrandomized, noncomparative study.

INTERVENTION

All patients received intravenous vincristine, etoposide, and carboplatin,. The tumors were managed with chemoreduction alone (group W) or chemoreduction combined with thermotherapy (group X), cryotherapy (group Y), or both thermotherapy and cryotherapy (group Z).

MAIN OUTCOME MEASURE

Tumor recurrence in each treatment group.

RESULTS

Of 457 retinoblastomas, 63 (14%) were in group W, 256 (56%) in group X, 127 (28%) in group Y, and 11 (2%) in group Z. The tumor was located in the macula in 33 (52%) of group W, 109 (43%) of group X, 3 (2%) of group Y, and 9 (1%) of group Z. The mean tumor thickness at initial examination was 7 mm for group W, 4 mm for group X, 2 mm for group Y, and 3 mm for group Z. Using Kaplan-Meier estimates, recurrence of the individual retinoblastoma at 7 years was found in 45% of group W and 18% for combined groups X, Y, and Z. Risk factors predictive of tumor recurrence by multivariate analysis included macular tumor location for all groups and additionally female gender for group W and increasing tumor thickness for groups X, Y, and Z.

CONCLUSIONS

Chemoreduction alone or combined with cryotherapy or thermotherapy is effective for treatment of retinoblastoma, but tumor recurrence rate is highest for those located in the macula and those with greater thickness.

Thermochemotherapy in hereditary retinoblastoma

BACKGROUND/AIM

The combination of chemotherapy and transpupillary thermotherapy, thermochemotherapy (TCT) has become an established part of the treatment plan in advanced retinoblastoma. The aim of this study was to identify safe indications, the complications as well as the limitations of this new treatment for retinoblastoma.

METHODS

Tumour response and side effects of TCT with an indirect laser ophthalmoscope (spot size about 400 micro m) in 55 tumours of 26 children with bilateral retinoblastoma were analysed. Using the Reese-Ellsworth classification system, nine of 35 eyes were classified as type I, 13 eyes as type II, 10 eyes as type III, and three eyes as type V. The mean age of the children was 0.74 (SD 0.61) years. The mean tumour height was 3.5 (2.3) mm with a mean diameter of 6.1 (4.1) mm. Treatment parameters were 4.3 (1.6) (median 5) thermochemotherapy sessions with a mean energy of 539 (211) mW and a mean duration of 13.5 (5.6) minutes. Chemotherapy courses (vincristine, etoposide, and carboplatin) were repeated every 3 weeks. The mean follow up period was 1.25 (0.6) years.

RESULTS

Local recurrence occurred in 21 tumours (38%), with a mean onset of 3.2 (2.9) months after TCT. The risk of tumour recurrence was correlated with tumour height. The recurrence rate was 17% for tumours with a height less than 2 mm, 37% for tumours with a height between 2 and 4 mm, and 63% for larger retinoblastomas. Multivariate analysis identified fish flesh regression after TCT (p = 0.0007) as the most important risk factor for tumour recurrence besides tumour height (p = 0.001) and the necessity of increased laser power during TCT sessions (p = 0.018). Complications during therapy included transient corneal opacification in two eyes (6%), focal iris atrophy (three eyes, 8.5%), peripheral lens opacity (two eyes, 6%), circumscribed transient retinal detachment (one eye, 3%) and diffuse choroidal atrophy (one eye, 3%).

CONCLUSION

TCT using an indirect laser ophthalmoscope with a spot size of about 400 micro m was efficient for retinoblastoma with a tumour height less than 4 mm. In larger tumours, the recurrence rate was unacceptably high. Fish flesh regression after TCT correlates with a higher rate of local tumour recurrence. Treatment related complications occurred in less than 9% of the treated eyes.

Localized whole eye radiotherapy for retinoblastoma using a (125)I applicator, "claws"

PURPOSE

To treat children with retinoblastoma, who require whole eye radiotherapy, with a specially designed (125)I applicator that irradiates the eye while sparing the surrounding tissues.

METHODS AND MATERIALS

Under general anesthesia, a pericorneal ring is attached to the 4 extraocular muscles, and 4 appendages, each loaded with (125)I seeds, are inserted beneath the conjunctiva in-between each pair of muscles and attached anteriorly to the ring. Twenty-nine eyes were treated. Eighteen received a median dose of 28 Gy during 91 hours and 11 received 40 Gy during 122 hours, when the relative biologic effectiveness was taken as 1 instead of 1.5. Six had received prior chemotherapy.

RESULTS

Twenty-four eyes were followed up for 2-157 months (median 29). Although 22 eyes responded, local control was achieved in 13 patients, 3 of whom required additional treatment for new tumors; a further 3 required additional treatment for tumor recurrence as well as new tumors. One of these eyes was enucleated for neovascular glaucoma. All 6 Group I-III eyes and 6 of 18 Group V eyes were retained for 2-157 months (median 39), with good vision in 10 eyes. Three developed cataracts 7, 8, and 12 years later, 1 of which has been removed.

CONCLUSIONS

This is a new way of irradiating the whole eye with a minimal dose to the surrounding tissues. The treatment time is only 5 days. It is effective in Groups I-III, but only 33% of Group V eyes retained vision. No late cosmetic defects occurred.

First-line chemotherapy with local treatment can prevent external-beam irradiation and enucleation in low-stage intraocular retinoblastoma

PURPOSE

To evaluate the efficacy of first-line chemotherapy (CT) in preventing external-beam radiotherapy (EBR) and/or enucleation in patients with retinoblastoma (Rbl).

PATIENTS AND METHODS

Twenty-four patients with newly diagnosed unilateral or bilateral Rbl received CT associated with local treatment (LT). Two to five courses of etoposide and carboplatin were administered at 3- to 4-week intervals, depending on tumor response, and were completed each time by LT.

RESULTS

Tumor response was observed in all eyes. Twenty-one of 24 patients showed a complete response (CR) that persisted at a median follow-up (FU) of 31 months (range, 4 to 41 months). Among the three patients who relapsed, two were lost to FU and one died of progressive disease. CR was achieved by CT and LT alone in 15 (71.4%) of 21 patients with less advanced disease (groups I to III). Six other patients with advanced disease (groups IV and V) experienced treatment failure and needed salvage treatment by EBR and/or enucleation. The difference between the two patient groups with regard to disease stage was statistically significant (P <.0001). EBR could be avoided in 13 (68.4%) of 19 patients, who presented with groups I to III (15 eyes) and group V (one eye) disease, whereas enucleation could be avoided in only two (40%) of five.

CONCLUSION

CT combined with intensive LT is effective in patients with groups I to III Rbl, permitting the avoidance of EBR in the majority of these young children and, thus, reducing the risk of long-term sequelae. This is in contrast with the disappointing results for patients with groups IV and V Rbl, in whom EBR and/or enucleation was needed.

Suicide gene therapy for treatment of retinoblastoma in a murine model

Children presenting with large retinoblastomas are currently treated by enucleation. As most patients are young children, the long-term repercussions of such surgery are often devastating. Subsequent radiation or chemotherapy, although effective in managing residual tumor, greatly increase the probability of the development of second malignancies later in life. Smaller tumors can sometimes be managed with local cryo- or laser surgery, thus saving the eye. The hypothesis that gene therapy could be used to reduce the tumor size sufficiently to allow local control was tested using a murine model of retinoblastoma. Y79Rb human retinoblastoma cells can be killed in vitro when transduced with an adenoviral vector containing the herpes simplex thymidine kinase gene (AdV-TK) followed by treatment with the prodrug ganciclovir. Intravitreal injections of Y79Rb cells in immunodeficient mice produce an aggressive, metastatic murine model of retinoblastoma. When these murine retinoblastomas were transduced in vivo with AdV-TK and the animals treated with intraocular injections of ganciclovir, 70% showed a complete ablation of detectable tumor. Treated animals had a significant prolongation of progression-free survival as compared with untreated controls. Gene therapy effectively reduced the tumor burden in this murine model of retinoblastoma. Thus gene therapy, in conjunction with local surgical control, may provide an effective alternative to enucleation, systemic chemotherapy, or radiotherapy for treatment of large, nonmetastatic retinoblastomas in children.

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.

Surgical repair of rhegmatogenous retinal detachment after treatment for retinoblastoma

OBJECTIVE

This study aimed to evaluate the causes of rhegmatogenous retinal detachment in children with retinoblastoma and to assess the surgical approach and results of retinal reattachment surgery.

DESIGN

The study design was a retrospective review of all children in whom a rhegmatogenous retinal detachment developed after treatment for retinoblastoma over a 20-year period.

PARTICIPANTS

Nine children, 5 to 33 months of age, participated.

MAIN OUTCOME MEASURES

Assessment of the treatment methods for retinoblastoma, apparent cause of the rhegmatogenous retinal detachment, interval from the most recent retinoblastoma treatment until repair of the rhegmatogenous retinal detachment, method of surgical repair, and long-term anatomic and visual results were measured.

RESULTS

Rhegmatogenous retinal detachment was diagnosed in nine eyes of nine children with treated retinoblastoma. Prior treatment of retinoblastoma included cryotherapy (n = 5), laser photocoagulation (n = 1), external beam radiation therapy (n = 7), and systemic chemotherapy (n = 4). An atrophic retinal hole was present at the most recent site of cryotherapy in three eyes and of laser photocoagulation in one eye. Extreme retinal thinning with a possible retinal break was noted in two eyes at a cryotherapy site. A dialysis was noted in one eye, and a retinal break could not be detected in two eyes. Treatment of retinoblastoma tumors was performed between 1 week and 15 years before retinal reattachment surgery. The retinal detachment was repaired externally with a scleral buckling procedure in seven eyes, with subretinal fluid drainage in five eyes, and without drainage in two eyes. Cytologic evaluation of subretinal fluid was performed in three eyes and showed no tumor cells. The retinal detachment was repaired by pars plana vitrectomy in one eye, and the vitrectomy specimen showed no tumor cells. In one child, the retinal detachment was not repaired. The retina remained attached after surgery in five eyes with follow-up ranging from 5 to 115 months. In three eyes, retinal redetachment associated with recurrent viable intraocular retinoblastoma was noted after surgery, necessitating enucleation. In no case was orbital or metastatic retinoblastoma detected at follow-up.

CONCLUSIONS

Rhegmatogenous retinal detachment in children with treated retinoblastoma generally originates from an atrophic retinal hole at the site of prior cryotherapy or laser photocoagulation. If there appears to be complete regression of the intraocular tumor after treatment, surgical repair of the rhegmatogenous retinal detachment may be approached cautiously.

MR-guided interstitial cryotherapy of the liver with a novel, nitrogen-cooled cryoprobe

The purpose of the study was to test a newly developed, MR-compatible, liquid nitrogen-cooled cryoprobe. The probe has an outer diameter of 3.5 mm and was specifically developed for percutaneous, MR-guided, interstitial cryotherapy. The probe was inserted percutaneously into the livers of 10 rabbits. The cryotherapy procedure was monitored with a surface coil in a 1.5 Tesla magnet using a gradient echo sequence. Follow-up examinations were performed 3 and 7 days after the freezing procedure using T1- and T2-weighted spin echo sequences. At 7 days the animals were sacrificed and the cryolesions were examined histologically. The cryoprobe enabled artifact-free MR imaging of the "iceball" formation during freezing of the rabbit liver. After 1 min of freezing, the iceball at the tip of the probe showed an average maximum diameter of 10.8 mm. No bleeding complications were observed during or after the freezing procedure. Histologic examination 7 days after cryotherapy confirmed that the liver lesions were the same size as had been predicted by the images of the acute iceball. This new, percutaneously inserted, MR-compatible, liquid-nitrogen cooled cryoprobe allows accurate, artifact-free MR imaging of interstitial cryotherapy.

History of cryosurgery

The use of freezing temperatures for the therapeutic destruction of tissue began in England in 1845-51 when James Arnott described the use of iced salt solutions (about-20 degrees C) to freeze advanced cancers in accessible sites, producing reduction in tumor size and amelioration of pain. Improved freezing techniques were possible early in the 1990s when solidified carbon dioxide came into use and later when liquid nitrogen and nitrous oxide became available. Nevertheless, cryotherapy was a minor technique, used only for the accessible lesions of skin and mucosa. With the development of modern cryosurgical apparatus by Cooper in 1961, a resurgence of interest in cryosurgery was initiated and techniques for diverse clinical conditions, including visceral cancer, evolved, After the initial widespread clinical trials matured in the 1970s, some applications of the technique fell into disuse while others became standard treatment. Late in the 1980s, further improvements in apparatus and imaging techniques have permitted increased clinical use in neoplastic disease, including visceral cancer.

Management of massive orbital involvement of intraocular retinoblastoma

OBJECTIVE

This study aimed to evaluate various combinations of therapeutic approaches in an attempt to improve the poor outcome of advanced cases of orbital involvement of intraocular retinoblastoma.

DESIGN

The study design was a retrospective, uncontrolled descriptive case series of consecutive patients with massive orbital retinoblastoma treated and observed at a referral center.

PARTICIPANTS

Sixteen patients with unilateral orbital involvement of intraocular retinoblastoma were studied. Eight patients had orbital involvement at initial presentation and eight children presented with orbital tumor after enucleation for intraocular retinoblastoma. Patients having microscopic evidence of tumor invasion at surgical section of the optic nerve and subsequently receiving other forms of treatment were not included in the study.

INTERVENTION

Six patients had orbital exenteration followed by external beam radiation therapy (4600-6000 cGy in fractionated doses) and chemotherapy. Five patients received chemotherapy only. Three patients were treated by exenteration and chemotherapy, whereas two patients underwent radiation therapy and chemotherapy.

MAIN OUTCOME MEASURES

Tumor regression monitored by clinical observations and imaging studies and patient survival was studied.

RESULTS

The median follow-up was 22 months (range, 4-168 months). All forms of treatment caused satisfactory local and systemic tumor regression. Two children achieved a survival of more than 10 years. However, two patients in the exenteration followed by chemotherapy and radiation therapy group and one who received chemotherapy only had central nervous system metastases develop and died. Only one patient was lost to follow-up.

CONCLUSION

Highly individualized aggressive treatment by combining radical surgery, chemotherapy, and external beam radiation therapy allowed most of the authors' patients to have longer survival and disease-free intervals than expected.