A new era for the treatment of retinoblastoma

MRI features for prediction of the intravenous chemotherapy effect in patients with retinoblastoma

AIM

To investigate the value of orbital magnetic resonance imaging (MRI) features in predicting the efficacy of intravenous chemotherapy (IVC) for patients with retinoblastoma (RB).

MATERIALS AND METHODS

The pretreatment clinical and MRI data of 100 eyes from 80 RB patients who underwent IVC were collected retrospectively. There were 59 eyes in the effective group and 41 eyes in the ineffective group, and the baseline data of the two groups were compared statistically. Three radiologists reviewed and evaluated each lesion independently based on 25 MRI features. The predictive values of the MRI features for IVC efficacy were assessed by multi-factor logistic regression analysis, and their odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. Receiver operating characteristic curves (ROCs) with the area under the curve (AUC) were used to determine the predictive abilities. A predictive model was constructed by integrating all independent predictors visualised by the nomogram.

RESULTS

There were no statistically significant differences in sex or age between the effective and ineffective groups. The results of multivariate regression analysis showed that laterality, margin, and anterior eye segment enhancement were identified as independent factors that could predict IVC efficacy. The predictive model combining these three features was constructed, and it had an AUC of 0.732 (95% CI: 0.633, 0.831, p<0.01), a sensitivity of 71.2%, and a specificity of 70.7%.

CONCLUSION

The data demonstrate that the orbital MRI features can be used to predict IVC efficiency before RB patients are treated.

Evaluation of macular vascular density and foveal avascular zone changes by optical coherence tomography angiography (OCT-A) after intravitreal dexamethasone implant in diabetic macular edema resistant to Anti-VEGF treatment

PURPOSE

Analysis of foveal avascular zone (FAZ) width and vascular density (VD) changes before and after intravitreal dexamethasone implant (IDI) treatment in diabetic macular edema (DME) patients resistant to anti-VEGF treatment.

METHODS

In this retrospective study, patients who were regularly treated with at least 5 doses of intravitreal Anti-VEGF (bevacizumab, ranibizumab or aflibercept) for DME and whose DME continued were considered resistant to Anti-VEGF and were treated with IDI for the first time. Thirty-four eyes of 34 patients were included in the study. FAZ and VD values of optical coherence tomography angiography (OCT-A) scans at 0, 1 and 3 months were examined.

RESULTS

In OCT-A measurements, the pre-IDI superficial plexus FAZ (SFAZ) area (0.350 ± 0.120 mm²) was decreased at 1 (0.292 ± 0.132 mm², p < 0.001) and at 3 months (0.311 ± 0.153 mm², p = 0.017). Pre-IDI deep plexus FAZ (DFAZ) area (0.651 ± 0.313 mm²) was decreased at 1-month post-IDI (0.481 ± 0.247 mm², p < 0.001) while no significant change was observed at 3 months (0.575 ± 0.259 mm², p = 0.197). There was no significant change in the mean post-IDI total VD rate in both superficial (pre 39.2% ± 2.4; 1st month 39.2% ± 2.6%; 3rd month 39.5% ± 3.4%) and deep retinal plexus (pre 43.3% ± 2.6%; 1st month 43.5 ± 2.8%; 3rd month 43.6% ± 4.6%) (p = 0.408 and p = 0.607, respectively).

CONCLUSION

The study showed that IDI caused a significant decrease in the FAZ area without any change in VD in patients with DME resistant to the anti-VEGF agents. IDI might be related to a decrease in the macular ischemia secondary to diabetic retinopathy.

Retinoblastoma: emerging concepts in genetics, global disease burden, chemotherapy outcomes, and psychological impact

In this review we discuss several recent concepts regarding retinoblastoma control and its impact. In a cohort of 482 patients with solitary unilateral retinoblastoma revealed germline mutation in 16% and the likelihood of germline retinoblastoma was greater for younger children (≤1 year versus (vs.) >1 year at presentation) with odds ratio (OR) 2.96 (p = 0.001), and greatest for the youngest infants (≤3 months vs. >3-12 months) (OR 5.52) (p = 0.002). Retinocytoma/retinoma, a benign variant of retinoblastoma, was studied in 78 tumours and demonstrated transformation into retinoblastoma in 9.2% by 5 years and 15.3% by 10 years and 20 years. An international global study on retinoblastoma over 1.5 years revealed 4351 new patients and 85% from low- and middle-income countries, notably with older age at detection and greater risk for metastasis. Management of retinoblastoma in 964 eyes using intravenous chemotherapy showed 20-year globe salvage at 96% in group A, 90% in group B, 90% in group C, 68% in group D, and 32% in group E eyes. The 5-year globe salvage with intra-arterial chemotherapy for 160 eyes (655 infusions) with retinoblastoma showed success in 100% for group B, 80% for group C, 78% for group D, and 55% for group E. The psychological impact of retinoblastoma on the parents revealed depression (73%), anxiety (64%), and/or stress (100%), and on the patient revealed deficits in quality of life issues. Retinoblastoma is a challenging disease and chemotherapy provides reliable tumour control and globe salvage. Continuing efforts to improve quality of life issues is important.

The Predictive Value of the Eighth Edition of the Clinical TNM Staging System for the Likelihood of Eye Salvage for Intraocular Retinoblastoma by Systemic Chemotherapy and Focal Therapy

BACKGROUND

The American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) cTNM staging is emerging as a universal staging for all cancers, including retinoblastoma.

METHODS

Here we evaluated the predictive value of the eighth edition AJCC/UICC cTNM staging in comparison with the International Intraocular Retinoblastoma Classification for eye globe salvage by primary systemic chemotherapy and focal therapy (CRD) using logistic regression model for the probability of treatment failure.

RESULTS

The eye salvage rate for 565 treated eyes was 95% (n=139/147) for T1 tumors (98% for T1a and 93% for T1b), 56% (n=230/410) for T2 (81% for T2a and 53% for T2b), and 0% for T3 tumors, and was 98%, 93%, 76%, and 44% for group A, B, C, and D tumors, respectively. As estimated by odds ratios, T2 were 13.6-fold more likely to fail treatment than T1, and T1b, T2a, and T2b were 2.8-, 9.4-, and 35.1-fold more likely to fail treatment than T1a, respectively. Group B, C, and D tumors were 2.8-, 12.7-, and 50.1-fold more likely to fail treatment than group A tumors, respectively. Eye salvage rate was 62% for eyes with focal seeds (3 mm close to the tumor), and 42% for eyes with diffuse seeds (clouds more than 3 mm from tumor edge) (P<0.0001).

CONCLUSION

Both, the eighth edition cTNM classification and the International Intraocular Retinoblastoma Classification systems, can effectively predict eye salvage rates for retinoblastoma by CRD. Eyes with higher cT stages are more likely to experience treatment failure. Because the cT2b group is very heterogeneous, our findings suggest further division of this group based on the severity of vitreous/subretinal seeds, this should be revised in the next edition of cTNM system.

Prognostic Factors for Eye Globe Salvage by External Beam Radiation Therapy for Resistant Intraocular Retinoblastoma

PURPOSE:

To analyse the prognostic factors for eye salvage for eyes with intra-ocular retinoblastoma (RB) that is resistant to systemic chemotherapy and focal therapy by external beam radiation therapy (EBRT).

METHODS:

A retrospective analysis of 28 eyes with intra-ocular RB that was resistant for systemic chemotherapy and focal consolidation therapy and received EBRT. Outcome measures included tumor stage at diagnosis, stage migration, type of tumor seeds, treatment modalities, eye globe salvage, metastasis, and survival.

RESULTS:

Most of the patients (83%) had bilateral RB, and 42% were females. All eyes were treated initially by combination of systemic chemotherapy and focal consolidation therapy. The dose of EBRT was 45 Gy. The mean follow-up was 6.5 years, and the overall eye globe salvage rate post EBRT was 46%: 67% (2/3) for group B, 71% (5/7) for group C, and 33% (6/18) for group D. Patient's gender, tumor site, laterality, and tumor stage at diagnosis were not significant prognostic factors (p> 0.05) for final outcome. The significant poor prognostic factors were tumor stage migration during systemic chemotherapy (p= 0.03) and presence of vitreous seeds at time of EBRT (p=0.001). Post EBRT complication rate was 68% (19/28) including; retinal detachment (3), vitreous hemorrhage (4), neovascular glaucoma (1), cataract (16), radiation retinopathy (2), and second malignancy (2).

CONCLUSION:

EBRT is an alternative for enucleation when RB is resistant to combined chemoreduction/focal consolidation therapy in absence in vitreous seeds. The known risks for EBRT are not justified for patients with unilateral RB and for those who have functional vision in the other eye.

Sclero-conjunctival ischaemia secondary to intra-arterial chemotherapy for retinoblastoma

Purpose

Intra-arterial chemotherapy (IAC), delivered directly to the globe via the internal carotid artery is now an established treatment for retinoblastoma. We report a case of anterior segment ischaemia following treatment with multiple intra-arterial chemotherapy (IAC) infusions.

Observations

A 5 month old female presented with bilateral retinoblastoma and was treated with 12 infusions of IAC. Her right eye was enucleated at diagnosis. After her seventh IAC treatment, she developed ipsilateral sixth and third cranial nerve palsies. After the twelfth IAC, she developed an area of conjunctival and scleral ischaemia between 12 and 3 o'clock meridians in her left eye. However, she maintained visual acuity of LogMAR 0.34.

Conclusions and Importance

The median number of IAC treatments in large studies is three. It is possible that repeated doses of IAC have an accumulative negative effect on the ocular blood supply, risking anterior segment and neurologic sequelae. This case highlights the significant challenge of balancing the salvage of eyes and vision with the potentially significant morbidity associated with IAC.

The role of external beam radiation therapy for retinoblastoma after failure of combined chemoreduction and focal consolidation therapy

Purpose: To study the role of external beam radiation therapy (EBRT) for the treatment of retinoblastoma eyes that were not cured by combined systemic chemotherapy and focal consolidation therapy.Methods and Materials: A retrospective case series of 28 eyes for 24 retinoblastoma patients treated by EBRT after the failure of tumor controlled by chemotherapy and focal therapy. The main outcome measures included: international intraocular retinoblastoma classification stage (IIRC) and Reese Ellsworth (RE) stage, tumor seeding, treatment modalities, eye salvage, and survival.Results: The median age at diagnosis was 11 months. There were 14 (58%) males and 20 (83%) bilateral cases. All eyes were treated initially by systemic chemotherapy (range; 6-8 cycles). The dose of radiation used for all eyes was 45 Gray (Gy).The mean follow-up was 75months, and the overall eye salvage rate after EBRT was 13 (46%) eyes: 67% (2/3) for IIRC group B, 71% (5/7) for group C, and 33% (6/18) for group D eyes. Vitreous seeds and tumor stage migration during management by chemotherapy were the most important significant predictive factors for tumor control (p = .001 and 0.033, respectively).Conclusion: Eyes with retinoblastoma that failed chemotherapy followed by focal therapy were controlled with EBRT. However, the presence of vitreous seeds, stage migration during the course of chemotherapy, as well as good vision in the other eye may not justify the known risks of EBRT.

Intravitreal Melphalan Chemotherapy for Vitreous Seeds in Retinoblastoma

OBJECTIVE

To evaluate our experience with intravitreal melphalan chemotherapy as a second-line regimen for RB patients with refractory or recurrent vitreous seeds.

METHODS

A retrospective case series of 16 eyes from 16 patients with intraocular RB who received intravitreal melphalan chemotherapy using the antireflux injection technique. Data included demographics, stage at diagnosis, treatment modalities, side effects, eye salvage, and survival.

RESULTS

The total number of injections was 64 (median, 3 injections per eye; range, 3-8), and the median age at time of injection was 22 months (range, 9-63 months). Nine (56%) patients were males, and 13 (81%) patients had bilateral RB. Complete response was seen in 13 (81%) eyes: in 9 (100%) eyes with focal vitreous seeds and in 4 (57%) eyes with diffuse vitreous seeds (P=0.062). At a median follow-up of 18 months (range, 6-48 months), the eye salvage rate was 81%, local retinal toxicity confined to the site of injection was seen in 2/3 of the eyes, 2 (12%) eyes had cataract, and none of the patients had orbital recurrence and distant metastasis or was dead.

CONCLUSION

Intravitreal melphalan is a promising modality for treatment of vitreous seeds, and the dose of 20-30 μg of melphalan sounds to be safe and effective for refractory and recurrent vitreous seeds.μg of melphalan sounds to be safe and effective for refractory and recurrent vitreous seeds.

Retinoblastoma Control With Primary Intra-arterial Chemotherapy: Outcomes Before and During the Intravitreal Chemotherapy Era

PURPOSE

To compare outcomes of intra-arterial chemotherapy for retinoblastoma as primary therapy before (Era I) and during (Era II) the intravitreal chemotherapy era.

METHODS

In this retrospective interventional case series at a tertiary referral center, 66 eyes of 66 patients with untreated unilateral retinoblastoma were used. intraarterial chemotherapy into the ophthalmic artery under fluoroscopic guidance was performed using melphalan in every case, with additional topotecan as necessary. Intravitreal chemotherapy using melphalan and/or topotecan was employed as needed for active vitreous seeding. Globe salvage was measured based on the International Classification of Retinoblastoma (ICRB) during two eras.

RESULTS

The two eras encompassed 2008 to 2012 (intraarterial chemotherapy alone, Era I) and 2012 to 2015 (intraarterial chemotherapy plus intravitreal chemotherapy, Era II). Over this period, there were 66 patients with unilateral untreated retinoblastoma treated with primary intra-arterial chemotherapy. A comparison of features (Era I vs Era II) revealed no significant difference in mean patient age (24 vs 24 months), ICRB groups, mean largest tumor diameter (19 vs 17 mm), mean largest tumor thickness (10 vs 10 mm), vitreous seed presence (56% vs 59%), subretinal seed presence (67% vs 62%), retinal detachment (70% vs 66%), or vitreous hemorrhage (0% vs 5%). There was no significant difference in mean number of intra-arterial chemotherapy cycles (3 vs 3.1) or intraarterial chemotherapy dosages. Following therapy, there was a significant difference (Era I vs Era II) in the need for enucleation overall (44% vs 15%, P = .012), especially for group E eyes (75% vs 27%, P = .039). Four of the eyes that initiated therapy in Era I later required intravitreal chemotherapy during Era II. The enucleation rate was 0% for groups B and C in both eras and non-significant for group D (23% vs 13%). There were no patients with stroke, seizure, limb ischemia, extraocular tumor extension, secondary leukemia, metastasis, or death.

CONCLUSIONS

The current era of retinoblastoma management using intra-arterial chemotherapy plus additional intravitreal chemotherapy (as needed for vitreous seeding) has improved globe salvage in eyes with advanced retinoblastoma. [J Pediatr Ophthalmol Strabismus. 2016;53(5):275-284.].

Unilateral Retinoblastoma Managed With Intravenous Chemotherapy Versus Intra-Arterial Chemotherapy. Outcomes Based on the International Classification of Retinoblastoma

PURPOSE

The objective of this study was to compare outcomes after intravenous chemotherapy (IVC) versus intra-arterial chemotherapy (IAC) for unilateral retinoblastoma.

DESIGN

A retrospective comparative interventional case series.

METHODS

Patients with unilateral retinoblastoma managed with either IVC using vincristine, etoposide, and carboplatin or IAC using melphalan with or without topotecan with a minimum of 1-year follow-up were compared. The primary outcome measure was globe salvage.

RESULTS

Of 91 patients with unilateral retinoblastoma, IVC was employed in 42 (46%) cases and IAC in 49 (54%). By comparison (IVC vs IAC), patients in the IAC group had greater mean tumor diameter (14 vs 18 mm, P < 0.001) and thickness (7 vs 10 mm, P = 0.001), greater percentage with active vitreous seeds (29% vs 55%, P = 0.01), and greater total retinal detachment (10% vs 43%, P < 0.001). There were no cases of group A in either treatment arm. Globe salvage was not significantly different in groups B, C, or E, but there was significantly improved globe salvage with IAC for group D (48% vs 91%, P = 0.004). Control was significantly better with IAC for solid tumor (62% vs 92%, P = 0.002), subretinal seeds (31% vs 86%, P = 0.006), and vitreous seeds (25% vs 74%, P = 0.006). There were no patients with pinealoblastoma, second cancer, metastasis, or death in either group.

CONCLUSIONS

For unilateral retinoblastoma, IAC provided significantly superior globe salvage compared with IVC for group D eyes. In addition, IAC provided significantly superior control for solid tumor, subretinal seeds, and vitreous seeds.

Chemoreduction of Progressive Intraocular Retinoblastoma by Systemic Topotecan

PURPOSE

To evaluate our experience with systemic Toptecan (TPT) chemotherapy as a second-line systemic chemotherapeutic regimen for treatment of refractory or recurrent intraocular retinoblastoma (RB).

METHODS AND MATERIALS

A retrospective case series of 14 eyes from patients with intraocular RB who received systemic TPT as second-line chemotherapy from April 2008 until June 2010. The following data were collected: patient demographics, laterality, international intraocular retinoblastoma stage (ICRB) at diagnosis, treatment received before and after TPT, side effects related to TPT, eye salvage, and survival.

RESULTS

The median age at diagnosis was 5 months (range, 1-16 months), and the median age at starting TPT was 10 months (range, 8-24 months). There were 6 (60%) females and 9 (90%) patients; all with bilateral retinoblastoma. The median number of TPT cycles was three per patient (range, 1-6), and the total number of administered cycles was 29. After TPT therapy; 4 (29%) eyes showed favorable response, 3 (21%) eyes showed minimal regression, 5 (36%) eyes had stable disease, and 2 (14%) eyes showed tumor progression. At a median follow-up of 48 months; 9 (64%) eyes were salvaged, 3 (21%) eyes received radiation therapy, and 3 (21%) eyes were enucleated (one was post radiation). Grade 3/4 neutropenia were noticed in a total of 59% of given cycles and admission for febrile neutropenia was required after seven cycles.

CONCLUSIONS

Our report suggests that systemic TPT chemotherapy could be used as a salvage second-line regimen with low toxicity for patients with progressive intraocular retinoblastoma if systemic therapy is needed.

Retinoblastoma: A SEER Dataset Evaluation for Treatment Patterns, Survival, and Second Malignant Neoplasms

PURPOSE

To characterize treatment patterns, overall survival (OS), and risk of second malignant tumors in patients with retinoblastoma (RB) using the SEER (Surveillance Epidemiology and End Results) dataset.

DESIGN

Cohort study.

METHODS

The SEER dataset was used to identify cases of RB using ICD-03 histology codes. Special permission was granted by the SEER administration to release chemotherapy information for this study (information that is not available in the publically available SEER dataset). Treatment of RB for patients with locoregional disease was characterized as surgical therapy, radiation therapy, chemotherapy, or any form thereof across 4 time periods from 1975 to 2010. Observed-to-expected (O/E) ratios for second malignant neoplasms were calculated with the use of age-specific incidence rates.

RESULTS

There were 1452 cases of RB identified from 1975 to 2010, with 48% of patients being male and 30% presenting with bilateral disease. Treatment patterns over time of 1220 patients (84%) with localized disease showed an increase in chemotherapy (± any treatment) from 16.5% to 50.2% and a decrease in surgery (± any treatment) from 96.2% to 88.5% and decrease in radiation from 15.2% to 4.9% from the 1975-1979 time period to the 2000-2010 time period. The 10-year OS was 93.7%, 93.7%, 97.5%, and 97% for increasing time periods (1975-1979, 1980-1989, 1990-1999, 2000-2010, respectively; P = .029). Risk of second malignant neoplasms was highest among patients treated with radiotherapy with O/E ratio of 43 compared to 30 and 5 for chemotherapy and surgery alone, respectively.

CONCLUSION

Treatment trends for RB show an increase in chemotherapy utilization with a decrease in radiation therapy from 1975 to 2010. Second malignant neoplasms occurred mainly in patients treated with radiation therapy. Our series demonstrates improvement in survival in contemporary time periods, which parallels a shift in therapy toward chemotherapy with a decline in radiation therapy.

Retinoblastoma

Retinoblastoma is a rare cancer of the infant retina that is diagnosed in approximately 8,000 children each year worldwide. It forms when both retinoblastoma gene (RB1) alleles are mutated in a susceptible retinal cell, probably a cone photoreceptor precursor. Loss of the tumour-suppressive functions of the retinoblastoma protein (pRB) leads to uncontrolled cell division and recurrent genomic changes during tumour progression. Although pRB is expressed in almost all tissues, cone precursors have biochemical and molecular features that may sensitize them to RB1 loss and enable tumorigenesis. Patient survival is >95% in high-income countries but <30% globally. However, outcomes are improving owing to increased disease awareness for earlier diagnosis, application of new guidelines and sharing of expertise. Intra-arterial and intravitreal chemotherapy have emerged as promising methods to salvage eyes that with conventional treatment might have been lost. Ongoing international collaborations will replace the multiple different classifications of eye involvement with standardized definitions to consistently assess the eligibility, efficacy and safety of treatment options. Life-long follow-up is warranted, as survivors of heritable retinoblastoma are at risk for developing second cancers. Defining the molecular consequences of RB1 loss in diverse tissues may open new avenues for treatment and prevention of retinoblastoma, as well as second cancers, in patients with germline RB1 mutations.

Transfection of wtp53 and Rb94 genes into retinoblastomas of nude mice by ultrasound-targeted microbubble destruction

Using ultrasound-targeted microbubble destruction (UTMD), we transfected both wild-type p53 (wtp53) and Rb94 genes into retinoblastomas (RBs) of nude mice to investigate the inhibitory role of these two genes in RB development. The 40 tumor-bearing mice, which had been established by sub-retinal injection of an HXO-Rb44 cell suspension, were randomly divided into five groups: blank control group (C); blank plasmid group (M); wtp53 plasmid group (p53); Rb94 plasmid group (Rb94); wtp53 + Rb94 plasmid group (p53 + Rb94). For preparation of the DNA-loaded microbubbles, a pre-determined amount of blank plasmid, pVIVO1-p53, pVIVO1-Rb94 or pVIVO1-p53-Rb94 was added and mixed with the microbubbles. Then, these DNA-loaded microbubbles were respectively transfected into the animal model by UTMD. Vascular endothelial growth factor level and microvessel density of the tumor were determined by immunohistochemical staining. Apoptosis of tissues was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Expression of wtp53 and Rb94 at both the gene and protein levels was detected by RT-PCR (reverse transcription polymerase chain reaction) and Western blot, respectively. Transfection of both genes had greater inhibitory effects on RB development and resulted in lower levels of vascular endothelial growth factor, lower microvessel density and more obvious apoptosis than single-gene transfection (p < 0.05). The results indicate that the transfection of both genes into the RB by UTMD more strongly inhibited RB growth than transfection of a single gene.

Targeted retinoblastoma management: when to use intravenous, intra-arterial, periocular, and intravitreal chemotherapy

PURPOSE OF REVIEW

The management of retinoblastoma is complex and involves strategically chosen methods of enucleation, radiotherapy, chemotherapy, laser photocoagulation, thermotherapy, and cryotherapy. Chemotherapy has become the most common eye-sparing modality. There are four routes of delivery of chemotherapy for retinoblastoma, including intravenous, intra-arterial, periocular, and intravitreal techniques. The purpose of this review is to discuss the current rationale for each method and the anticipated outcomes.

RECENT FINDINGS

The diagnosis of retinoblastoma should be clinically established prior to embarking on a chemotherapy protocol. There are over 25 conditions that can closely simulate retinoblastoma in a young child. In addition, enucleation is an acceptable method for management, particularly with advanced retinoblastoma. Intravenous chemotherapy is generally used for germline mutation (bilateral, familial) retinoblastoma with excellent tumor control for groups A, B, and C and intermediate control for group D eyes. Intra-arterial chemotherapy is used as primary therapy in selected cases for nongermline mutation (unilateral) retinoblastoma with excellent control, and also used as secondary therapy for recurrent solid retinoblastoma, subretinal seeds, and vitreous seeds. Periocular chemotherapy is employed to boost local chemotherapy dose in advanced bilateral groups D and E eyes or for localized recurrences. Intravitreal chemotherapy is used for recurrent vitreous seeds from retinoblastoma. Patients at high risk for metastases should receive intravenous chemotherapy.

SUMMARY

Chemotherapy is effective for retinoblastoma and the targeted treatment route depends on the clinical features and anticipated outcomes.

Pinocembrin suppresses TGF-β1-induced epithelial-mesenchymal transition and metastasis of human Y-79 retinoblastoma cells through inactivating αvβ3 integrin/FAK/p38α signaling pathway

Background

Pinocembrin is the most abundant flavonoid in propolis. In this study, we investigated the antimetastatic effect of pinocembrin on TGF-β1-induced epithelial-mesenchymal transition (EMT) and metastasis of human Y-79 retinoblastoma cells.

Results

Firstly, the results showed that pinocembrin significantly suppresses the TGF-β1-induced abilities of the invasion and migration of Y-79 cells under non-cytotoxic concentration. Pinocembrin decreased TGF-β1-induced expression of vimentin, N-cadherin, αv and β3 integrin in Y-79 cells. Molecular data also showed pinocembrin inhibits the activation of focal adhesion kinase (FAK) and p38α signal involved in the downregulation of enzyme activities, protein and messenger RNA levels of matrix metalloproteinase-2/9 (MMP-2/-9) induced by TGF-β1. Next, pinocembrin also strongly inhibited the degradation of inhibitor of kappaBα (IκBα) and the nuclear levels of nuclear factor kappa B (NF-κB). Also, a dose-dependent inhibition on the binding ability of NF-κB was further observed under pinocembrin treatment.

Conclusions

Presented results indicated that pinocembrin inhibits TGF-β1-induced epithelial-mesenchymal transition (EMT) and metastasis of Y-79 cells by inactivating the αvβ3 integrin/FAK/p38α signaling pathway. Thus, our findings point to the anticancer potential of pinocembrin against retinoblastoma cells.

Outcome of retinoblastoma following limited sessions of intra-arterial chemotherapy in iran

Background:

The management of retinoblastoma remains a challenge to the multidisciplinary team, particularly as treatment affects not only visual outcomes, but also ocular retention and morbidity. Management of retinoblastoma has evolved over the past two decades.

Objectives:

To report the result of intra-ophthalmic artery chemotherapy (IAC) for the treatment of refractory and advanced retinoblastoma tumors.

Patients and Methods:

All patients who had failed to respond adequately to previous treatments and six naive patients with advanced retinoblastoma, receiving IAC between 2009 and 2012, were included in this institutional interventional case series. The patients received 1-2 treatments of IAC given 4-8 weeks apart. Complete response was defined as regressed tumor and complete disappearance of seeding clinically and partial response was defined as partial regression of the tumor with live parts of the tumor and/or lessening of seeds, but not complete disappearance of them clinically.

Results:

A total of 24 eyes of 24 patients were treated with IAC during the study period. The mean age at the time of IAC was 38.9 months (14-120 months), and the mean follow-up was 16.8 months (3-36 months) after IAC. Tumor control was achieved in 14 eyes (58.3%). Type 3 (combined fleshy and calcified remnants) was the most common type of regression (37.5%). Complications included vitreous hemorrhage in nine eyes (37.5%), arterial occlusion in two (8.3%), cyclitic membrane possibly secondary to ischemia and tractional retinal detachment in one patient (4.2%), chorioretinal atrophy in three (12.5%) patients, and neovascular glaucoma in one eye (4.2%). In eight (33.3%) patients, no complication happened. Globe salvage was achieved in 62.5% of the cases. The success rate for naive patients was 84%. Sixty-seven percent of the cases received transpupillary thermotherapy and cryotherapy before IAC.

Conclusions:

Intra-ophthalmic artery melphalan is an effective treatment for advanced cases of retinoblastoma, with a reasonable level of success. In the short follow up period of this study, it appears that the primary cases showed better results in the control of tumor.

Intravenous and intra-arterial chemotherapy for retinoblastoma: what have we learned?

PURPOSE OF REVIEW

To review the recent literature on two methods of chemotherapy for retinoblastoma using intravenous versus intra-arterial route.

RECENT FINDINGS

In 1996, the era of intravenous chemotherapy (chemoreduction) for retinoblastoma was introduced with major centers providing published information on impressive tumor control, without the need for external beam radiotherapy or enucleation. Later reports heralded continued impressive long-term control, minimal systemic toxicities, likely prevention of pinealoblastoma (trilateral retinoblastoma), and reduction in numbers of germline mutation second cancers. There is no reported ophthalmic toxicity and no evidence of reduction in fertility with chemoreduction. In 2011, the era of intra-arterial chemotherapy was announced with several studies and three conflicting editorials in the literature. This technique requires a catheterization through the arterial tree from the femoral artery into the ophthalmic artery. Outstanding tumor control is achieved with only three cycles, but more-than-expected ocular ischemic events have been noted. Further improvements in this technique could minimize complications.

SUMMARY

Both intravenous and intra-arterial chemotherapy are powerful methods for retinoblastoma control. In addition to tumor control, intravenous chemotherapy protects from systemic metastasis and pinealoblastoma, minimizes long-term second cancers, and has few systemic and no ocular toxicities. Intra-arterial chemotherapy provides excellent tumor control for slightly more advanced eyes with retinoblastoma and, in addition, can be used to treat eyes that fail other methods. However, local ocular toxicities can be vision-threatening and long-term systemic toxicities are not yet understood.

Pearls and pitfalls of intraarterial chemotherapy for retinoblastoma

Retinoblastoma is a deadly eye cancer in children, leading to death in 50%-70% of children in undeveloped nations who are diagnosed with it. This malignancy is the most common intraocular tumor in childhood worldwide. The good prognosis in developed nations is related to early detection and advanced treatments. With the advent of intraarterial chemotherapy, neurosurgeons have taken a central role in the treatment of this pediatric condition. Intraarterial chemotherapy is a novel treatment for retinoblastoma whereby chemotherapeutic agents are precisely delivered into the ophthalmic artery, minimizing systemic toxicity. This procedure has shown impressive results and has allowed a dramatic decrease in the rate of enucleation (eye removal) in advanced and refractory retinoblastoma. Recent reports have raised some concerns about the risk of ocular vasculopathy, radiation-related toxicity, and the potential for metastatic disease after intraarterial chemotherapy. In the authors' experience of more than 3 years, tumor control is excellent with globe salvage at 67% and vascular events less than 5%, mostly related to improvement in technique. The role of this novel approach in the management of retinoblastoma has yet to be defined. As more centers are adopting the technique, the topic will decidedly become the focus of intensive future research. In this paper, the authors review and discuss current data regarding intraarterial chemotherapy for retinoblastoma.

Fluorescein angiographic findings after intra-arterial chemotherapy for retinoblastoma

PURPOSE

To evaluate fluorescein angiography (FA) findings after intra-arterial chemotherapy (IAC) for retinoblastoma.

DESIGN

Retrospective case series.

PARTICIPANTS

Twenty-four eyes of 24 patients.

INTERVENTION

Fifty-five IAC procedures for delivery of melphalan 5 mg and possible carboplatin 30 mg.

MAIN OUTCOME MEASURES

Vascular flow of iris, retina, and choroid after IAC.

RESULTS

All patients received melphalan 5 mg, whereas the first 6 patients also were treated with additional carboplatin 30 mg. The IAC was performed as primary treatment in 17 eyes and as secondary treatment (after systemic chemotherapy) in 7 eyes. Two patients also received external-beam radiotherapy before IAC. At presentation, FA revealed neovascularization of the iris (NVI) in 8 eyes, and after IAC, complete NVI regression was noted in 5 eyes (63%). After a mean follow-up of 13 months after IAC, FA depicted the main tumor with decreased fluorescence in 22 eyes (92%). After 55 ophthalmic artery catheterizations, retinal vascular abnormalities by FA were detected in 7 eyes (13%) and choroidal vascular abnormalities were detected in 6 eyes (11%). The retinal abnormalities included ophthalmic artery obstruction (n = 1), transient ophthalmic artery spasm (n = 1), central retinal artery obstruction (n = 1), branch retinal artery obstruction (n = 2), and peripheral retinal ischemia (n = 2). Additional retinal neovascularization was found in 1 patient. The choroidal abnormalities included sector (n = 5) or diffuse (n = 1) choroidal nonperfusion. New-onset iris neovascularization was found in 2 patients. Retinal vascular abnormalities were diagnosed after median of 1 month after the first IAC, whereas choroidal vascular abnormalities were found after median of 5 months after the first IAC.

CONCLUSIONS

Fluorescein angiography suggests that vascular perfusion to the retina and the choroid can be compromised after IAC for retinoblastoma. The most common vascular abnormality was choroidal sector or diffuse nonperfusion.

Irresponsiveness of two retinoblastoma cases to conservative therapy correlates with up- regulation of hERG1 channels and of the VEGF-A pathway

Background

Treatment strategies for Retinoblastoma (RB), the most common primary intraocular tumor in children, have evolved over the past few decades and chemoreduction is currently the most popular treatment strategy. Despite success, systemic chemotherapeutic treatment has relevant toxicity, especially in the pediatric population. Antiangiogenic therapy has thus been proposed as a valuable alternative for pediatric malignancies, in particolar RB. Indeed, it has been shown that vessel density correlates with both local invasive growth and presence of metastases in RB, suggesting that angiogenesis could play a pivotal role for both local and systemic invasive growth in RB. We present here two cases of sporadic, bilateral RB that did not benefit from the conservative treatment and we provide evidence that the VEGF-A pathway is significantly up-regulated in both RB cases along with an over expression of hERG1 K⁺ channels.

Case presentation

Two patients showed a sporadic, bilateral RB, classified at Stage II of the Reese-Elsworth Classification. Neither of them got benefits from conservative treatment, and the two eyes were enucleated. In samples from both RB cases we studied the VEGF-A pathway: VEGF-A showed high levels in the vitreous, the vegf-a, flt-1, kdr, and hif1-α transcripts were over-expressed. Moreover, both the transcripts and proteins of the hERG1 K⁺ channels turned out to be up-regulated in the two RB cases compared to the non cancerous retinal tissue.

Conclusions

We provide evidence that the VEGF-A pathway is up-regulated in two particular aggressive cases of bilateral RB, which did not experience any benefit from conservative treatment, showing the overexpression of the vegf-a, flt-1, kdr and hif1-α transcripts and the high secretion of VEGF-A. Moreover we also show for the first time that the herg1 gene transcripts and protein are over expressed in RB, as occurs in several aggressive tumors. These results further stress the relevance of the VEGF-A pathway in RB and the correlation with hERG1, making aggressive and recurrent RB cases good candidates for antiangiogenesis therapies based on the targeting of VEGF-A.

Experimental Research on Wild-type p53 Plasmid Transfected into Retinoblastoma Cells and Tissues using an Ultrasound Microbubble Intensifier

The transfection efficiency of wild-type p53 ( wtp53) was investigated in retinoblastoma (RB) Y79 cells using an ultrasound microbubble technique. A human RB nude mouse xenograft tumour model was also used to investigate whether this technique could deliver wtp53 into solid tumours. Reverse transcription–polymerase chain reaction (RT–PCR) demonstrated that wtp53 was successfully transfected into Y79 cells in the plasmid with microbubbles and ultrasound group and in the plasmid with liposomes group, but not in the plasmid with ultrasound group or in the untreated control group. Flow cytometry showed that apoptosis was highest in the microbubbles and ultrasound group (25.58%) compared with the plasmid with liposomes group (19.50%), and the other two groups (< 10%). RT–PCR also showed that the wtp53 gene was successfully transfected into solid tumours in the plasmid with microbubbles and ultrasound group. This study provides preliminary evidence in support of a potential new approach to RB gene therapy.

Evaluation of the antitumor effects of Herpes simplex virus lacking ribonucleotide reductase in a murine retinoblastoma model

PURPOSE

To determine if an attenuated herpes simplex virus (HSV) lacking the large subunit of ribonucleotide reductase has antitumor effects in a transgenic mouse model of retinoblastoma (LHbetaTAg).

METHODS

LHbetaTAg mice were injected ocularly with 1 x 10(6) pfu of the hrR3 virus and tumor sizes were measured 3 weeks later. Replication of the virus in the eye and cultured murine retinoblastoma cells was tested by titration. Distribution of the virus in tumor was measured by X-gal staining.

RESULTS

Intraocular injection of mice with hrR3 (n = 24) did not result in a significant reduction in tumor size compared to uninjected (n = 24) or PBS injected controls (n = 16). Neither the hrR3, nor the HSV RE6 mutant, which was previously shown to have antitumor effects in vivo, replicated in cultured murine tumor cells in vitro, compared to wild-type HSV. The hrR3 virus also did not replicate significantly in tumor cells in vivo, compared to normal eye tissue.

CONCLUSIONS

These results suggest that mutant HSV lacking ribonucleotide reductase do not display oncolytic activity in the LHbetaTAg mouse and that this model may not be suitable for studying viral oncolysis as a therapy for retinoblastoma.

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.

Iodine 125 plaque radiotherapy as salvage treatment for retinoblastoma recurrence after chemoreduction in 84 tumors

PURPOSE

To assess tumor control and complications of iodine 125 (I125) plaque radiotherapy for retinoblastoma recurrence after chemoreduction (CRD).

DESIGN

Interventional retrospective case series.

PARTICIPANTS

Children with retinoblastoma treated on the Oncology Service, Wills Eye Hospital, initially examined from July 1994 to April 2005.

METHODS

Eighty-four retinoblastomas with solid recurrence after CRD were treated with custom designed I125 plaque radiotherapy. Eyes with vitreous or subretinal seed recurrence were excluded. The CRD regimen included vincristine, etoposide, and carboplatin for 6 cycles plus local consolidation with thermotherapy or cryotherapy. The only alternatives to plaque radiotherapy in these cases would have been external beam radiotherapy (EBRT), additional chemotherapy, or enucleation.

MAIN OUTCOME MEASURES

Tumor control and radiation complications.

RESULTS

Tumor control was achieved in 95% of eyes by 5 years follow-up. Of the 59 recurrent tumors after CRD alone, 56 (95%) were controlled with plaque radiotherapy. Of the 25 recurrent tumors after CRD and EBRT, 100% were controlled with plaque radiotherapy. Of the 3 failures after plaque radiotherapy, the median time to failure (tumor recurrence) was 4 months and all recurrences were detected within 1 year. There were no identifiable factors predictive of plaque radiotherapy failure. Using Kaplan-Meier analysis, radiation complications at 5 years included proliferative retinopathy (19%), nonproliferative maculopathy (24%), papillopathy (16%), transient mild vitreous hemorrhage (54%), cataract (43%), iris neovascularization (NVI; 8%), and glaucoma (4%). Nonresolving vitreous hemorrhage and scleral necrosis did not occur. Radiation complications showed minimal change at 10 and 15 years of follow-up.

CONCLUSIONS

Iodine 125 plaque radiotherapy offers 95% tumor control for selected retinoblastomas that fail CRD. Complications such as radiation retinopathy and mild vitreous hemorrhage should be anticipated, depending on the location, size, and extent of the tumor.

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.

Toxicity and dose-response studies of 1-alpha hydroxyvitamin D2 in LH-beta-tag transgenic mice

PURPOSE

To determine the effectiveness of a vitamin D analog, 1alpha-hydroxyvitamin D(2) (1alpha-OH-D(2)), in inhibiting retinoblastoma in a transgenic retinoblastoma model (LHbeta-Tag mouse) and to evaluate its toxicity.

DESIGN

Experimental study using an animal (LHbeta-Tag transgenic mouse) randomized (controlled) trial.

PARTICIPANTS AND CONTROLS

Two hundred seventeen LHbeta-Tag transgene-positive 8- to 10-week-old mice total; 179 drug-treated animals, 38 control animals.

METHODS

Mice were fed a vitamin D- and calcium-restricted diet and were randomized to treatment groups receiving control (vehicle), or 0.1, 0.3, 0.5, or 1.0 micro g/day of 1alpha-OH-D(2) via oral gavage 5 times weekly for 5 weeks. Body weight was measured at the start of treatment and twice weekly during treatment. Animals were euthanized on the last day of treatment. The eyes were enucleated, processed histologically, and serially sectioned. Representative sections from the superior, middle, and inferior regions of each globe were examined microscopically and tumor areas were measured using Optimas software. Serum was collected for serum calcium levels. Kidneys were removed for histologic processing and were analyzed microscopically for kidney calcification.

MAIN OUTCOME MEASURES

Mean tumor area was measured to determine drug effectiveness. Toxicity was assessed by survival, weight loss over the treatment period, serum calcium, and kidney calcification.

RESULTS

The mean tumor size in each 1alpha-OH-D(2) group was smaller than controls (all P values < 0.02): control, 90,248 micro m(2); 0.1 micro g, 31,545 micro m(2); 0.3 micro g, 16,750 micro m(2); 0.5 micro g, 30,245 micro m(2); and 1.0 micro g, 16,049 micro m(2). No dose-dependent response curve was evident. The survival percentage for each group was as follows: control, 97%; 0.1 micro g, 91%; 0.3 micro g, 88%; 0.5 micro g, 70%; and 1.0 micro g, 63%. Mortality was higher in the 0.5- micro g and 1.0- micro g doses (P values < 0.01) compared with other treatment groups and with the control group. Serum calcium levels were significant in all treatment groups compared with controls (all P values < 0.0001).

CONCLUSIONS

In the LHbeta-Tag mouse, 1alpha-OH-D(2) inhibits retinoblastoma with no significant increase in mortality in lower doses (0.1-0.3 micro g). 1alpha-OH-D(2) has approval by the Food and Drug Administration as an investigative drug for cancer treatment, and has shown efficacy with low toxicity in adult cancer trials. 1alpha-OH-D(2) meets the criteria for human clinical trials.

Vitamin D analogs, a new treatment for retinoblastoma: The first Ellsworth Lecture

PURPOSE

This lecture honors the memory of Dr. Robert M. Ellsworth, an important figure in the development of current treatments of retinoblastoma (RB), and reviews our studies of vitamin D analogs as treatments for retinoblastoma in two experimental mouse models. We identified vitamin D receptors in retinoblastoma and examined the effectiveness and mechanism of action of these analogs.

METHODS

Reverse-transcriptase polymerase chain reaction (RT-PCR) amplification was used to detect vitamin D receptor mRNAs in human and mouse retinoblastomas. The effectiveness and toxicity of vitamin D(2), calcitriol, and synthetic analogs were studied in the athymic/Y-79 xenograft and transgenic mouse models of RB. Dosing was 5X/week for five weeks. Dose-response studies focused on tumor inhibition; toxicity studies investigated survival and serum calcium. The mechanism of action of vitamin D was investigated using terminal transferase dUTP labeling 3'-overhang ligation to measure apoptosis; immunohistochemistry measured p53-dependent gene expression and cell proliferation.

RESULT

Vitamin D receptor mRNAs were detectable in Y-79 RB cells, LH beta-Tag tumors, and human RB specimens using RT-PCR. Calcitriol inhibited cell growth in vitro. Calcitriol and vitamin D(2) inhibited in vivo growth in xenograft and transgenic models, but therapeutic levels were toxic due to hypercalcemia. Two analogs, 16,23-D(3) and 1 alpha-OH-D( 2), inhibited tumors in animal models of RB with reduced toxicity. The mechanism of action appears related to increased p53-related gene expression resulting in increased apoptosis.

CONCLUSION

16,23-D(3) and 1 alpha-OH-D(2) are effective in tumor reduction in two mouse models of RB with low toxicity. These results warrant initiating phase 1 and phase 2 clinical studies in children.

Chemoreduction plus focal therapy for retinoblastoma: factors predictive of need for treatment with external beam radiotherapy or enucleation

PURPOSE

To report the results of chemoreduction and focal therapy for retinoblastoma with determination of factors predictive of the need for treatment with external beam radiotherapy or enucleation.

DESIGN

Interventional case series.

METHODS

One-hundred three patients with retinoblastoma (158 eyes with 364 tumors) at the Ocular Oncology Service at Wills Eye Hospital of Thomas Jefferson University in conjunction with the Division of Oncology at Children's Hospital of Philadelphia from June 1994 to August 1999 were enrolled for this prospective clinical trial. The patients received treatment for retinoblastoma with six planned cycles (one cycle per month) of chemoreduction using vincristine, etoposide, and carboplatin combined with focal treatments (cryotherapy, thermotherapy, or plaque radiotherapy). The two main outcome measures after chemoreduction and focal therapy were the need for external beam radiotherapy and the need for enucleation. The clinical features at the time of patient presentation were analyzed for impact on the main outcome measures using a series of Cox proportional hazards regressions.

RESULTS

Using Reese-Ellsworth (RE) staging for retinoblastoma, there were nine (6%) eyes with group I disease, 26 (16%) eyes with group II disease, 16 (10%) eyes with group III disease, 32 (20%) eyes with group IV disease, and 75 (48%) eyes with group V retinoblastoma. All eyes showed initial favorable response with tumor regression. The median follow-up was 28 months (range, 2-63 months). Failure of chemoreduction and need for treatment with external beam radiotherapy occurred in 25% of eyes at 1 year, 27% at 3 years, and no further increase at 5 years. More specifically, external beam radiotherapy was necessary at 5 years in 10% of RE groups I-IV eyes and 47% of RE group V eyes. Multivariate factors predictive of treatment with external beam radiotherapy included non-Caucasian race, male sex, and RE group V disease. Failure of chemoreduction and the need for treatment with enucleation occurred in 13% eyes at 1 year, 29% at 3 years, and 34% at 5 years. More specifically, enucleation was necessary in 15% of RE groups I-IV eyes at 5 years and in 53% of RE group V at 5 years. Multivariate factors predictive of treatment with enucleation included patient age older than 12 months, single tumor in eye, and tumor proximity to foveola within 2 mm. Overall, of the 158 eyes, 50% required external beam radiotherapy or enucleation and 50% were successfully managed without these treatments. No patient developed retinoblastoma metastasis, pinealoblastoma, or second malignant neoplasms over the 5-year follow up.

CONCLUSIONS

Chemoreduction offers satisfactory retinoblastoma control for RE groups I-IV eyes, with treatment failure necessitating additional external beam radiotherapy in only 10% of eyes and enucleation in 15% of eyes at 5-year follow-up. Patients with RE group V eyes require external beam radiotherapy in 47% and enucleation in 53% at 5 years.

The treatment of retinoblastoma: a case study

Research in the treatment of retinoblastoma and multidrug resistance has led to new treatment protocols for children. This case study introduces information regarding a clinical trial for the treatment of intraocular retinoblastoma. It also highlights important nursing issues in the care of these children and their families.

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.