Guillermo L Chantada

Hospital Sant Joan de Déu, Barcino, Catalonia, Spain

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Publications (81)227.79 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To review the ocular pharmacology and antitumor activity of topotecan for the treatment of retinoblastoma by an evaluation of different routes of administration.
    Retina (Philadelphia, Pa.) 08/2014; · 2.93 Impact Factor
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    ABSTRACT: Intravitreal melphalan is emerging as an effective treatment for refractory vitreous seeds in retinoblastoma, but there is limited understanding regarding its toxicity. This study evaluates the retinal and systemic toxicity of intravitreal melphalan in retinoblastoma patients, with preclinical validation in a rabbit model. Clinical and preclinical, prospective, cohort study. In the clinical study, 16 patient eyes received 107 intravitreal injections of 30 μg melphalan given weekly, a median of 6.5 times (range, 5-8). In the animal study, 12 New Zealand/Dutch Belt pigmented rabbits were given 3 weekly injections of 15 μg of intravitreal melphalan or vehicle to the right eye. Electroretinogram (ERG) responses were recorded in both humans and rabbits. For the clinical study, ERG responses were recorded at baseline, immediately before each injection, and at each follow-up visit; 82 of these studies were deemed evaluable. Median follow-up time was 5.2 months (range, 1-11). Complete blood counts (CBCs) were obtained on the day of injection at 46 patient visits. In the animal study, ERG responses were obtained along with fluorescein angiography, CBCs, and melphalan plasma concentration. After humane killing, the histopathology of the eyes was evaluated. For the clinical study, we measured peak-to-peak ERG amplitudes in response to 30-Hz photopic flicker stimulation with comparisons between ERG studies before and after intravitreal melphalan. For the animal study, we collected ERG parameters before and after intravitreal melphalan injections with histopathologic findings. By linear regression analysis, over the course of weekly intravitreal injections in retinoblastoma patients, for every additional injection, the ERG amplitude decreased by approximately 5.8 μV. The ERG remained stable once the treatment course was completed. In retinoblastoma patients, there were no grade 3 or 4 hematologic events. One week after the second injection in rabbits, the a- and b-wave amplitude declined significantly in the melphalan treated eyes compared with vehicle-treated eyes (P<0.05). Histopathology revealed severely atrophic retina. Weekly injections of 30 μg of melphalan can result in a decreased ERG response, which is indicative of retinal toxicity. These findings are confirmed at an equivalent dose in rabbit eyes by ERG measurements and by histopathologic evidence of severe retinal damage. Systemic toxicity with intravitreal melphalan at these doses in humans or rabbits was not detected.
    Ophthalmology 05/2014; · 5.56 Impact Factor
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    ABSTRACT: An increased incidence of retinoblastoma in some developing countries has been reported but no conclusive data are available from population-based studies at national level. To report the incidence and survival of retinoblastoma in Argentina from the National Pediatric Cancer Registry (ROHA) and the influence of socio-economical indicators on outcome. Cases reported to the ROHA (2000-2009) were analyzed. Incidence rates were calculated using National Vital Statistics and survival was estimated. The extended human development index (EHDI) was used as a socio-economical indicator. With 438 patients reported, an incidence of 5.0 cases per million children 0-14 years old (95% CI 3.5-6.4) was calculated. Median age at diagnosis was significantly higher for children from provinces with lower EHDI; (24 vs. 35 months for unilateral, (P = 0.003) and 9 versus 11.5 months for bilateral retinoblastoma (P = 0.027). The 3-year probability of survival was 0.87 and 0.94 for unilateral and bilateral retinoblastoma, respectively. Residents in provinces with higher EHDI had a better 3-year survival (0.93 vs. 0.77 for lower EHDI, P < 0.0001). Probability of survival was higher for patients treated at tertiary level institutions (P = 0.0015). The combination of low EHDI residence province with no treatment at a tertiary institution was associated with the worst survival outcome. For both, unilateral and bilateral disease, children who died were in average diagnosed at older age. The incidence of retinoblastoma in Argentina is comparable to that of developed countries. Retinoblastoma is diagnosed later and survival is lower in the less developed areas of the country. Pediatr Blood Cancer 2014;9999:1-6. © 2014 Wiley Periodicals, Inc.
    Pediatric Blood & Cancer 04/2014; · 2.35 Impact Factor
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    ABSTRACT: We report a retrospective review of patients with retinoblastoma and anterior segment invasion (ASI) as risk factors for extraocular relapse. Only those with ASI combined with postlaminar optic nerve invasion and/or scleral invasion received adjuvant chemotherapy and those with tumor at the resection margin received orbital radiotherapy. Those with only uveal invasion did not receive adjuvant therapy. Of 479 evaluable patients, 67 patients had pathologically confirmed ASI, including 52 with anterior chamber invasion and 47 with iris or ciliary body invasion. ASI occurred with other pathology risk factors (25 had concomitant posterior uveal invasion, 36 had postlaminar optic nerve invasion, 11 with cut-end invasion, and 25 with scleral invasion). The 5-year disease-free survival (pDFS) was 0.9 (95% CI, 0.8-0.95) for children with ASI with no significant differences among children with other pathology risk factors with and without ASI. ASI was not significantly associated with extraocular relapse in multivariate analysis. There were no significant differences in pDFS for patients with anterior chamber invasion and those with iris-ciliary body invasion (pDFS 0.89 [95% CI, 0.65-0.96] vs. 0.93 [95% CI, 0.61-0.98]). To conclude, ASI was seen with other pathology risk factors and it did not add a significant risk for extraocular relapse.
    Journal of Pediatric Hematology/Oncology 04/2014; · 0.97 Impact Factor
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    ABSTRACT: ABSTRACT Purpose: To describe a technique for micro catheterization of the external ophthalmic artery (EO) in pigs for investigational and training purposes. Methods: Carotid angiography was performed in seven male domestic pigs. The external ophthalmic artery was reached with a microcatheter in order to administer a neoplastic drug in the eye. Results: The external ophthalmic artery could be found arising from the infraorbital (IO) artery in the bend of the internal maxillary (IM) artery. It could be reached in every animal. Conclusion: Following anatomic landmarks of the external carotid (EC) artery the ophthalmic artery can be easily reached and catheterized for training and investigational purposes.
    Journal of Investigative Surgery 03/2014; · 1.32 Impact Factor
  • Guillermo L Chantada, Ira J Dunkel, David H Abramson
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    ABSTRACT: While intraocular retinoblastoma is highly curable and current treatments are aimed to preserve vision, once the disease has extended outside the eye, the chances of cure are significantly lower. Thus, extraocular dissemination is the leading cause of death caused by retinoblastoma worldwide. Its extent is estimated by imaging studies upon diagnosis, but they are useful only when there is a massive extraocular dissemination. Histopathological examination of the enucleated eye is used to evaluate microscopic invasion of the choroid, the optic nerve and the sclera, and postoperative therapy is decided upon this information. Since extraocular dissemination is uncommon in developed countries, there are few studies that provided evidence to support adjuvant therapy. When there is overt extraocular disease, children should be treated with neoadjuvant therapy followed by delayed enucleation and adjuvant therapy. The treatment of extraocular retinoblastoma and the controversies in its management are the subject of this review.
    Expert Review of Ophthalmology 01/2014; 7(1).
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    ABSTRACT: To obtain baseline knowledge about the current use of intra-arterial chemotherapy (SSOAIC) in centers worldwide.
    International Journal of Ophthalmology 01/2014; 7(4):726-30. · 0.12 Impact Factor
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    ABSTRACT: Purpose Intravitreal melphalan is emerging as an effective treatment for refractory vitreous seeds in retinoblastoma, but there is limited understanding regarding its toxicity. This study evaluates the retinal and systemic toxicity of intravitreal melphalan in retinoblastoma patients, with preclinical validation in a rabbit model. Design Clinical and preclinical, prospective, cohort study. Participants In the clinical study, 16 patient eyes received 107 intravitreal injections of 30 μg melphalan given weekly, a median of 6.5 times (range, 5–8). In the animal study, 12 New Zealand/Dutch Belt pigmented rabbits were given 3 weekly injections of 15 μg of intravitreal melphalan or vehicle to the right eye. Methods Electroretinogram (ERG) responses were recorded in both humans and rabbits. For the clinical study, ERG responses were recorded at baseline, immediately before each injection, and at each follow-up visit; 82 of these studies were deemed evaluable. Median follow-up time was 5.2 months (range, 1–11). Complete blood counts (CBCs) were obtained on the day of injection at 46 patient visits. In the animal study, ERG responses were obtained along with fluorescein angiography, CBCs, and melphalan plasma concentration. After humane killing, the histopathology of the eyes was evaluated. Main Outcome Measures For the clinical study, we measured peak-to-peak ERG amplitudes in response to 30-Hz photopic flicker stimulation with comparisons between ERG studies before and after intravitreal melphalan. For the animal study, we collected ERG parameters before and after intravitreal melphalan injections with histopathologic findings. Results By linear regression analysis, over the course of weekly intravitreal injections in retinoblastoma patients, for every additional injection, the ERG amplitude decreased by approximately 5.8 μV. The ERG remained stable once the treatment course was completed. In retinoblastoma patients, there were no grade 3 or 4 hematologic events. One week after the second injection in rabbits, the a- and b-wave amplitude declined significantly in the melphalan treated eyes compared with vehicle-treated eyes (P<0.05). Histopathology revealed severely atrophic retina. Conclusion Weekly injections of 30 μg of melphalan can result in a decreased ERG response, which is indicative of retinal toxicity. These findings are confirmed at an equivalent dose in rabbit eyes by ERG measurements and by histopathologic evidence of severe retinal damage. Systemic toxicity with intravitreal melphalan at these doses in humans or rabbits was not detected.
    Ophthalmology 01/2014; · 5.56 Impact Factor
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    ABSTRACT: To assess the antitumor activity, toxicity, and plasma pharmacokinetics of the combination of melphalan and topotecan for superselective ophthalmic artery infusion (SSOAI) treatment of children with retinoblastoma. Single-center, prospective, clinical pharmacokinetic study. Twenty-six patients (27 eyes) with intraocular retinoblastoma. Patients with an indication for SSOAI received melphalan (3-6 mg) and topotecan (0.5-1 mg; doses calculated by age and weight). Plasma samples were obtained for pharmacokinetic studies, and a population approach via nonlinear mixed effects modeling was used. Safety and efficacy were assessed and compared with historical cohorts of patients treated with melphalan single-agent SSOAI. Melphalan and topotecan pharmacokinetic parameters and efficacy and safety parameters. Twenty-seven eyes from 26 consecutive patients received 66 cycles of SSOAI melphalan and topotecan in combination. All 5 eyes treated as primary therapy responded to the combination chemotherapy and were preserved. Sixteen of the 22 eyes with relapsed or resistant tumors responded, but 3 of them ultimately underwent enucleation at a median of 8 months (range, 7.9-9.1 months). The incidence of grade III and IV neutropenia was 10.6% and 1.5%, respectively, which was comparable with historical controls of single-agent SSOAI melphalan. No episode of fever neutropenia was observed, and no patient required transfusion of blood products. The large variability in melphalan pharmacokinetics was explained by body weight (P <0.05). Concomitant topotecan administration did not influence melphalan pharmacokinetic parameters. There was no effect of the sequence of melphalan and topotecan administration in plasma pharmacokinetics. A regimen combining melphalan and topotecan for SSOAI treatment of retinoblastoma is active and well tolerated. This combination chemotherapy previously showed synergistic pharmacologic activity, and we herein provide evidence of not increasing the hematologic toxicity compared with single-agent melphalan.
    Ophthalmology 12/2013; · 5.56 Impact Factor
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    ABSTRACT: Few studies were reported from developing countries regarding patient outcome and ocular survival in children with bilateral retinoblastoma treated with chemoreduction compared to external beam radiotherapy (EBRT). We undertook a retrospective study of three treatment eras: (1) (1988-1995) n = 68 when EBRT was used as primary conservative therapy; (2) (1995-2003) n = 46 when carboplatin-based systemic chemoreduction was introduced and (3) (2003-2009) (n = 83) when additional periocular chemotherapy was added for advanced tumors and pre-enucleation chemotherapy was given for those with massive buphthalmia. The probability of 5-year disease-free survival was 0.94 (95% confidence interval [CI] 0.91-0.98%) without significant differences among the three eras. Chemoreduction reduced the use of EBRT from 84.6% to 68.7% in eras 1 and 3, respectively (P = 0.008), which was more evident in cases with less advanced disease. Chemoreduction also significantly improved the 5-year probability of preservation of eyes with advanced disease from 0.13 (95% CI 0.04-0.27) during era 1 to 0.49 (95% CI 0.34-0.62) in era 3 (P < 0.0001). Chemoreduction was not associated with changes in the probability of extraocular relapse, which was reduced after the introduction of pre-enucleation chemotherapy. Second malignancies occurred in nine cases, acute myeloid leukemia being the most fatal one. Trilateral retinoblastoma occurred in three cases and all of them had been exposed to chemotherapy. Chemoreduction reduced the need for EBRT in eyes with less advanced disease and improved the preservation of eyes with advanced disease while its effects on secondary malignancies or trilateral disease remain unclear. Pediatr Blood Cancer © 2013 Wiley Periodicals, Inc.
    Pediatric Blood & Cancer 11/2013; · 2.35 Impact Factor
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    ABSTRACT: IMPORTANCE Different staging systems for extraocular retinoblastoma have been published, but to date they have not been validated in large cohorts. OBJECTIVE To review 533 patients (and pathology slides) with retinoblastoma included in 4 protocols (January 1, 1988, to December 31, 2009) who received uniform treatment. DESIGN AND SETTING Retrospective review in a hospital setting. A critical analysis for detecting inconsistencies and omissions was performed. PARTICIPANTS Patients were reclassified according to the modified St Jude Children's Research Hospital staging system, Grabowski-Abramson staging system, International Retinoblastoma Staging System (IRSS), and American Joint Committee on Cancer TNM staging system. MAIN OUTCOME AND MEASURE The main outcome measure was disease-free survival (DFS), considering only extraocular relapse as an event. RESULTS In the IRSS and the St Jude system, higher stages correlated with poorer DFS. For intraocular disease, only the TNM system and the IRSS included pathological definitions, and all systems except for the IRSS included substages without differences in DFS. Omissions of factors significantly associated with lower DFS included scleral invasion by the TNM system and massive choroidal invasion by the Grabowski-Abramson system. The St Jude system omits postlaminar optic nerve involvement, but this omission did not correlate significantly with lower DFS because these patients received intensive therapy. No differences in DFS were observed among substages for metastatic disease except for the presence of central nervous system involvement. All staging systems had inconsistencies in definitions of extent of disease. No system provides guidelines for imaging. CONCLUSIONS AND RELEVANCE Only the IRSS and the St Jude system allowed for grouping of patients with increasing risk of extraocular relapse. For lower stages, only the IRSS considers all unequivocal pathological prognostic factors. For higher stages, all systems had redundant information, resulting in an excess of substages.
    Jama Ophthalmology 06/2013; · 3.83 Impact Factor
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    ABSTRACT: AIM: To evaluate minimally disseminated disease (MDD) in cytologically negative cerebrospinal fluid (CSF) specimens of patients with high-risk retinoblastoma by the detection of the synthase of ganglioside GD2 mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR). METHODS: The CSF was evaluated in 26 patients with high risk for CSF relapse: 14 with postlaminar optic nerve invasion, five of them with tumour at the resection margin, five with massive choroidal invasion, three with overt orbital extension and four patients with systemic metastasis. Serial CSF examinations were repeated at different time intervals according to stage and in the event of suspected relapse. GD2 synthase mRNA was evaluated by RT and nested PCR at each procedure. RESULTS: MDD was present at diagnosis in six cases (23%) and it was significantly associated to massive optic nerve involvement or history of glaucoma (p<0.05). Three of the children with positive MDD had a CSF relapse. Thirteen patients had negative MDD at diagnosis and one had a CSF relapse. In seven children no ARN could be obtained for PCR analysis and two subsequently relapsed. The probability of CSF relapse was 0.50 (95% confidence interval (CI) 0.13-0.88) for children with MDD and 0.08 (95% CI 0.02-0.46) for those with negative RT-PCR examination of the CSF at diagnosis (p=0.03). CONCLUSIONS: MDD in the CSF detected by RT-PCR for GD2-synthase mRNA occurred in 31.7% of evaluable high-risk children with retinoblastoma with no initial central nervous system (CNS) involvement. It was significantly associated to optic nerve involvement and glaucoma and increased risk of CSF relapse.
    European journal of cancer (Oxford, England: 1990) 05/2013; · 4.12 Impact Factor
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    ABSTRACT: Retinoblastoma remains incurable in many regions of the world. The major obstacles to cure are delayed diagnosis, poor treatment compliance, and lack of evidence-based recommendations for clinical management. Although enucleation is curative for intraocular disease, in developing countries retinoblastoma is often diagnosed after the disease has disseminated beyond the eye. A SIOP-PODC committee generated guidelines for the clinical management of retinoblastoma in developing countries and developed a classification system based on the resources available in those settings. Recommendations are provided for staging and treatment of unilateral and bilateral retinoblastoma and counseling of families for whom compliance is an issue. Pediatr Blood Cancer © 2013 Wiley Periodicals, Inc.
    Pediatric Blood & Cancer 01/2013; · 2.35 Impact Factor
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    ABSTRACT: Treatment of intraocular retinoblastoma with vitreous seeding is a challenge. Different routes of chemotherapy administration have been explored in order to attaining pharmacological concentrations into the posterior chamber. Intravitreal drug injection is a promissing route for maximum bioavailability to the vitreous but it requires a well defined dose for achieving tumor control while limited toxicity to the retina. Topotecan proved to be an promising agent for retinoblastoma treatment due to its pharmacological activity and limited toxicity. High and prolonged concentrations were achieved in the rabbit vitreous after 5 μg of intravitreal topotecan. However, whether a lower dose could achieve potentially therapeutic levels remained to be determined. Thus, we here study the pharmacokinetics of topotecan after 0.5 μg and the toxicity profile of intravitreal topotecan in the rabbit eye as a potential treatment of retinoblastoma. A cohort of rabbits was used to sudy topotecan disposition in the vitreous after a single dose of 0.5 μg of intravitreal topotecan. In addition, an independent cohort of non-tumor bearing rabbits was employed to evaluate the clinical and retinal toxicity after four weekly injections of two different doses of intravitreal topotecan (Group A, 5μg/dose; Group B, 0.5 μg/dose) to the right eye of each animal. The same volume (0.1 ml) of normal saline was administered to the left eye as control. A third group of rabbits (Group C) served as double control (both eyes injected with normal saline). Animals were weekly evaluated for clinical and hematologic values and ocular evaluations were perfomed with an inverse ophthalmoscope to establish potential topotecan toxicity. Weekly controls included topotecan quantitation in plasma of all rabbits. Electroretinograms (ERGs) were recorded before and after topotecan doses. One week after the last injection, topotecan concentrations were measured in vitreous of all eyes and samples for retinal histology were obtained. Our results indicate that topotecan shows non linear pharmacokinetics after a single intravitreal dose in the range of 0.5 to 5 μg in the rabbit. Vitreous concentration of lactone topotecan were close to the concentration assumed to be therapeutically active after 5 hours of 0.5 μg intravitreal administration. Eyes injected with four weekly doses of topotecan (0.5 or 5 μg/dose) showed no significant differences in their ERG wave amplitudes and implict times in comparison with control (p>0.05). Animals showed no weight, hair loss or significant changes in hematologic values during the study period. There were no significant histologic damage of the retinas exposed to topotecan treatments. After intravitreal administration no topotecan could be detected in plasma during the follow-up period nor in the vitreous of treated and control animals after 1 week of the last injection. The present data shows that four weekly intravitreal injection of 5 μg of topotecan is safe for the rabbit eye. Despite multiple injections of 0.5 μg of topotecan are also safe to the rabbit eye, lactone topotecan vitreous concentrations were potentially active only after 5 hours of the administration. We postulate promising translation to clinics for retinoblastoma treatment.
    Experimental Eye Research 01/2013; · 3.03 Impact Factor
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    ABSTRACT: ABSTRACT Background: Retinoblastoma is a hereditary cancer of childhood caused by mutations in the RB1 tumor suppressor gene. An early diagnosis is critical for survival and eye preservation, thus identification of RB1 mutations is important for unequivocal diagnosis of hereditary retinoblastoma and risk assessment in relatives. Methods: We studied 144 families for 20 years, performing methodological changes to improve detection of mutation. Segregation analysis of polymorphisms, MLPA, FISH and cytogenetic assays were used for detection of "at risk haplotypes" and large deletions. Small mutations were identified by heteroduplex/DNA sequencing. Results: At risk haplotypes were identified in 11 familial and 26 sporadic cases, being useful for detection of asymptomatic carriers, risk exclusion from relatives and uncovering RB1 recombinations. Ten large deletions (eight whole gene deletions) were identified in six bilateral/familial and four unilateral retinoblastoma cases. Small mutations were identified in 29 cases (four unilateral retinoblastoma patients), being the majority nonsense/frameshift mutations. Genotype-phenotype correlations confirm that the retinoblastoma presentation is related to the type of mutation, but some exceptions may occur and it is crucial to be considered for genetic counseling. Three families included second cousins with retinoblastoma carrying different haplotypes, which suggest independent mutation events. Conclusion: This study enabled us to obtain information about molecular and genetic features of patients with retinoblastoma in Argentina and correlate them to their phenotype.
    Ophthalmic Genetics 01/2013; · 1.07 Impact Factor
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    ABSTRACT: Treatment recommendations for endemic Burkitt lymphoma (BL) in settings with only minimum requirements for curative treatment (PODC setting 1) are described. The reported cure rate for endemic BL is usually <50%. Facilities within setting 1 differ. Three treatment schedules are proposed based on: (1) when accurate staging is not possible, (2) when staging is possible and for (3) relapses and poor responders to primary therapy. A literature review and personal experience were used to formulate the recommendations. Recorded 1-year event free survival was 48% for treatment 1, 61% for treatment 2, and 35% for the rescue treatment. Pediatr Blood Cancer © 2012 Wiley Periodicals, Inc.
    Pediatric Blood & Cancer 11/2012; · 2.35 Impact Factor
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    ABSTRACT: BACKGROUND: Treatment of eyes with retinoblastoma failing systemic chemoreduction and external beam radiotherapy is seldom efficacious. This study compares the efficacy and toxicity of intra-arterial ophthalmic artery chemotherapy (IAO) to our historical cohort of sequential periocular and systemic chemotherapy in such patients. PATIENTS AND METHODS: Eighteen eyes (15 consecutive patients) were retrospectively evaluated. Eight eyes received IAO for a median of four cycles (range: 2-9) including melphalan alone (n = 3) or after topotecan and carboplatin (n = 4) or topotecan and carboplatin without melphalan (n = 1). Ten eyes received a median of two cycles (range: 1-3) of periocular topotecan (n = 9) or carboplatin (n = 1) followed by intravenous topotecan and cyclophosphamide in three patients if at least stable disease was achieved. Both groups were comparable for disease extension and prior therapy. RESULTS: No extraocular dissemination or second malignancy occurred and all patients are alive. The probability of enucleation-free eye survival at 12 months was 0.87 (95% CI: 0.42-0.97) for the IAO group, compared to 0.1 (95% CI: 0.06-0.35) for the periocular group (P < 0.01). Ocular toxicity was mild and similar in both groups (mostly mild orbital edema). Systemic toxicity was low for IAO and periocular injection, but children who received sequentially intravenous chemotherapy (n = 12 cycles) had five episodes of grade 4 neutropenia, three of which resulted in hospitalizations. No case in the IAO group presented these complications. CONCLUSIONS: IAO is significantly superior to sequential periocular-intravenous topotecan-containing regimens in eyes with relapsed intraocular retinoblastoma with a more favorable toxicity profile. Pediatr Blood Cancer © 2012 Wiley Periodicals, Inc.
    Pediatric Blood & Cancer 09/2012; · 2.35 Impact Factor
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    ABSTRACT: Scant information about the early toxicity of high-dose chemotherapy regimens for the treatment of mature B-cell malignancies (B-non-Hodgkin lymphoma) in developing countries is available, so we performed a retrospective evaluation of children with B-non-Hodgkin lymphoma treated with Berlin-Frankfurt-Muenster-based protocols in Argentina (1993 to 2007). In the second protocol, induction chemotherapy was modified introducing high-dose cytarabine and etoposide (block CC) instead of high-dose methotrexate (block AA). Forty-one patients with stage III and elevated lactate dehydrogenase or stage IV or B-acute lymphoblastic leukemia were included. Five patients (12.1%) had an early death at a median of 23 days after treatment initiation, caused by sepsis in 4 and by a Stevens Johnson syndrome in 1. Children that had an early death were significantly more likely to present with renal failure (P=0.04) and have significantly higher levels of phosphate and creatinine on admission (P=0.02 and 0.008). Eighty percent of children dying early had prior extensive abdominal surgery and positive blood cultures after the first cycle. Induction with AA block was associated with a higher frequency of severe orointestinal toxicity (P=0.04). We conclude that renal failure was associated to increased risk of mortality leading to a higher risk of sepsis, especially in patients that underwent abdominal surgery.
    Journal of Pediatric Hematology/Oncology 07/2012; 34(7):e266-70. · 0.97 Impact Factor
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    ABSTRACT: To evaluate the outcome of children with different degrees of choroidal invasion, to compare different systems for grading the extent of choroidal invasion, and to assess the role of concomitant prelaminar optic nerve and anterior segment invasion as predictors of extraocular relapse. Retrospective analysis of children included in 4 prospective protocols (January 1, 1989, through June 31, 2010). Children with postlaminar optic nerve or scleral involvement and overt extraocular disease were excluded. Adjuvant chemotherapy was not scheduled. All slides were reviewed, and massive involvement was classified according to 3 definitions: (1) extending at least 3 mm in any dimension, (2) through the choroid's whole thickness, and (3) more than 50% of the thickness and/or more than 1 cluster. One hundred sixty-seven children (35 with massive invasion) were studied (136 did not receive adjuvant therapy). The probability of 5-year event-free survival was 98.1% and the probability of overall survival was 98.7% because 1 patient relapsed. Children with massive invasion had a significantly lower event-free survival probability (94.2%) compared with those with focal invasion (99.2%) (P = .04). However, no significant difference was found in overall survival probability (98.7% vs 99.2%; P = .29). No significant effect of other risk factors was found. Survival was excellent without adjuvant therapy, and no other factors correlated with survival. Children with massive invasion have a higher relapse rate but comparable survival to those with focal invasion provided that aggressive therapy for extraocular relapse is available with adequate safety conditions.
    Archives of ophthalmology 06/2012; 130(6):724-9. · 3.86 Impact Factor
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    ABSTRACT: To characterize melphalan pharmacokinetics after superselective ophthalmic artery infusion (SSOAI) in animals and children with retinoblastoma. Vitreous and plasma samples of five Landrace pigs were obtained over a 4-hour period after SSOAI of melphalan (7 mg). Melphalan cytotoxicity was evaluated in retinoblastoma cell lines with and without topotecan. Plasma samples were obtained from 17 retinoblastoma patients after SSOAI of 3 to 6 mg of melphalan to one (n=14) or two eyes (n=3). Correlation between plasma pharmacokinetics and age, dosage, and systemic toxicity was studied in patients. In animals, melphalan peak vitreous levels were greater than its IC50 and resulted in 3-fold vitreous-to-plasma exposure. In patients, a large variability in pharmacokinetic parameters was observed and it was explained mainly by body weight (P<0.05). A significantly higher systemic area under the curve was obtained in children receiving more than 0.48 mg/kg for bilateral tandem infusions (P<0.05). These children had 50% probability of grades 3-4 neutropenia. Plasma concentrations after 2 and 4 hours of SSOAI were significantly higher in these children (P<0.05). A synergistic cytotoxic effect of melphalan and topotecan was evident in cell lines. Potentially active levels of melphalan after SSOAI were achieved in the vitreous of animals. Low systemic exposure was found in animals and children. Doses greater than 0.48 mg/kg, given for bilateral tandem infusions, were associated with significantly higher plasma levels and increased risk of neutropenia. Synergistic in vitro cytotoxicity between melphalan and topotecan favors combination treatment.
    Investigative ophthalmology & visual science 05/2012; 53(7):4205-12. · 3.43 Impact Factor

Publication Stats

838 Citations
227.79 Total Impact Points

Institutions

  • 2014
    • Hospital Sant Joan de Déu
      Barcino, Catalonia, Spain
  • 1994–2014
    • Paediatric Hospital Dr. Juan P. Garrahan
      Buenos Aires, Buenos Aires F.D., Argentina
  • 2008–2013
    • St. Jude Children's Research Hospital
      • Department of Oncology
      Memphis, Tennessee, United States
    • Sister María Ludovica Children's Hospital
      Eva Perón, Buenos Aires, Argentina
  • 2007–2012
    • University of Buenos Aires
      • Faculty of Pharmacy and Biochemistry
      Buenos Aires, Buenos Aires F.D., Argentina
    • University of São Paulo
      San Paulo, São Paulo, Brazil
  • 2011
    • New York Hospital Queens
      New York City, New York, United States
    • Hospital Luis Calvo Mackenna
      CiudadSantiago, Santiago, Chile
  • 2010
    • Istanbul University
      İstanbul, Istanbul, Turkey
  • 2004–2010
    • Memorial Sloan-Kettering Cancer Center
      • Department of Pediatrics
      New York City, New York, United States
  • 2009
    • National University of Colombia
      Μπογκοτά, Bogota D.C., Colombia
  • 1999
    • Hospital Italiano de Buenos Aires
      Buenos Aires, Buenos Aires F.D., Argentina