Hearing Loss After Radiation and Chemotherapy for CNS and Head-and-Neck Tumors in Children

PURPOSE Hearing loss (HL) is a serious secondary effect of treatment for CNS and head-and-neck tumors in children. The goal of this study was to evaluate incidence and risk factors for HL in patients with multiple ototoxic exposures. PATIENTS AND METHODS We evaluated 340 ears from 171 patients with CNS or head-and-neck tumors treated with radiation, with or without chemotherapy, who had longitudinal audiologic evaluation. International Society of Pediatric Oncology-Boston grades were assigned to 2,420 hearing assessments. Multivariable weighted ordinal logistic regression was fitted to evaluate the effect of clinicopathologic features on HL. RESULTS Mean cochlea dose (odds ratio [OR] 1.04 per Gy, P < .001), time since radiotherapy (RT; OR 1.21 per year, P < .001), cisplatin dose (OR 1.48 per 100 mg/m2, P < .001), and carboplatin dose (OR 1.41 per 1,000 mg/m2, P = .002) were associated with increasing International Society of Pediatric Oncology-Boston grade of HL. There was no synergistic effect of RT and cisplatin (interaction term, P = .53) or RT and carboplatin (interaction term, P = .85). Cumulative incidence of high-frequency HL (> 4 kHz) was 50% or greater at 5 years after RT if mean cochlea dose was > 30 Gy, while incidence of HL across all frequencies continued to increase beyond 5 years after RT. CONCLUSION Children treated with radiation and chemotherapy experience a high incidence of HL over time, with associations found between more severe HL and cisplatin or carboplatin dose as well as mean cochlea dose. Mean cochlea dose of ≤ 30 Gy is proposed as a goal to reduce the risk of HL; a lower threshold (20-25 Gy) may be considered in patients receiving platinum chemotherapy to reduce cumulative HL burden.

Safety and Survival Outcomes in Lung Cancer Patients Receiving Carboplatin: Impact of Uncapped Dosage

The prescription of carboplatin is commonly based on the Calvert formula, and low serum creatinine values can lead to an overestimation of the glomerular filtration rate and of the carboplatin dose. Limited data recommend to cap carboplatin dose at 800 mg, but the risk of suboptimal carboplatin dose is concerning. This study compared hematologic toxicity occurrence and survival outcomes in lung cancer patients receiving carboplatin &#x3e; or &#x3c;800 mg based on the Calvert formula (target area under the curve = 5 mg/mL min). Our results show more severe cytopenia in patients receiving carboplatin &#x3e;800 mg with significant difference for all grades of thrombocytopenia in the uncapped group (37% patients vs. 3%, <i>p</i> = 0.02). For metastatic non-small-cell lung cancer patients, we also observed hematologic toxicity in the uncapped group with more severe anemia (30% of patients vs. 0%, <i>p</i> = 0.03) and all grades of thrombocytopenia (39 vs. 0%, <i>p</i> = 0.02) than the capped group. Concerning the secondary endpoint, we obtained a trend of lower progression-free survival and overall survival in patients receiving carboplatin &#x3e;800 mg, but no significant difference appears for the both survival criteria. This study aims to improve the determination of carboplatin dosage to know the real impact of carboplatin capping and to find the optimum balance between excessive toxicity and substandard therapeutics outcomes.

Carboplatin dose capping affects pCR rate in HER2-positive breast cancer patients treated with neoadjuvant Docetaxel, Carboplatin, Trastuzumab, Pertuzumab (TCHP)

Purpose Estimated glomerular filtration rate (eGFR) is commonly used to calculate carboplatin doses and capping the eGFR may be used to reduce the risk of excessive dosing and toxicity. We sought to retrospectively examine the impact of our carboplatin guidelines on pathological complete response rates (pCR) and toxicity in women with HER2+ breast cancer receiving neoadjuvant docetaxel, carboplatin, trastuzumab and pertuzumab (TCHP). Methods The delivered area under the curve (dAUC) was calculated [(actual carboplatin dose at cycle 1 ÷ dose calculated with uncapped/unbanded eGFR) × 6] and dichotomized at the median value. The impact of this and other clinical factors on pCR rate, dose intensity (DI) and toxicity was assessed. Results 124 eligible patients were identified of whom 63.7% (79/124) achieved pCR. The median dAUC at cycle 1 was 5.75 mg × ml/min. Those with lower dAUC were more frequently younger and overweight/obese. Patients with lower dAUC had significantly inferior pCR rates of 54.8% (34/62) vs 72.6% (45/62), respectively (p = 0.040). Similar results were seen in the ER+ subgroup; 45.2% (19/42) vs 68.3% (28/41), p = 0.037%, whereas no significant difference was seen among ER- patients; 75.0% (15/20) vs 81.0% (17/21), p = 0.72. DI and toxicity were comparable between the two dAUC groups. Conclusions The overall pCR rate was high in patients with HER2+ breast cancer receiving the TCHP regimen; however, carboplatin dose capping resulted in inferior pCR rates, particularly in the ER+ subgroup. To ensure optimal dosing, isotopic measurement of renal function is warranted in patients who would otherwise have their eGFR and dose capped.

Cisplatin and carboplatin pharmacokinetics in a pediatric patient with hepatoblastoma receiving peritoneal dialysis

Purpose Cisplatin and carboplatin are frequently used drugs in the treatment of pediatric hepatoblastoma. Dosing guidelines for these drugs in children requiring peritoneal dialysis are lacking. Here, we describe the case of a 3-year-old boy with pre-existing end-stage renal disease on peritoneal dialysis, requiring treatment with cisplatin and carboplatin for hepatoblastoma. Methods Pharmacokinetic data were generated to support clinical dosing decisions, with the aim of adequate exposure and minimal toxicity. In the first chemotherapy cycle, 25% of the standard cisplatin dose and 75% of the carboplatin dose, calculated using the pediatric Calvert formula, were administered. Free platinum concentrations were determined in plasma ultrafiltrate and dialysate samples drawn after administration of cis- and carboplatin. Results Cisplatin was well tolerated and the observed AUC of cisplatin were 15.3 and 14.3 mg/L h in cycles 1 and 3, respectively. The calculated AUC of carboplatin in cycle 1 (9.8 mg/mL min) exceeded target AUC of 6.5 mg/mL min and toxicity was observed; therefore, the dose was reduced in cycles 2 and 3. The observed AUC in cycles 2 and 3 was 5.4 and 5.7 mg/mL min respectively. Platinum concentrations in the dialysate showed that 3–4% of the total dose of cisplatin and 10–12% of the total dose of carboplatin were excreted via peritoneal dialysis. Chemotherapy enabled extended hemihepatectomy and complete remission was achieved. Conclusion This report shows that it is feasible to measure AUCs for both drugs and to individualize the dose of these drugs according to the PK results and clinical parameters. Our advice for future cases would be to calculate the starting dose of carboplatin using the (pediatric) Calvert formula, assuming a dialytic clearance of zero, and to adjust the dose if required, based on therapeutic drug monitoring.

Analysis of carboplatin dosing in patients with a glomerular filtration rate greater than 125 mL/min: To cap or not to cap? A retrospective analysis and review

The use of the Calvert formula to calculate carboplatin doses allows clinicians to achieve the appropriate carboplatin area under the concentration (AUC) curve. Thrombocytopenia is the dose limiting toxicity of carboplatin and optimizing AUC minimizes the risk of thrombocytopenia. Carboplatin clearance directly correlates with glomerular filtration rate (GFR) and, therefore, an accurate estimation of the renal function is needed. The Calvert formula was designed using the GFR measured by 51Cr-EDTA; however, many clinicians substitute estimated creatinine clearance (CrCl) as calculated by the Cockcroft–Gault (C–G) equation. The potential for overestimating AUC occurs when clinicians substitute actual weight in obese patients or use a low serum creatinine when calculating C–G estimated CrCl. In 2010, the National Cancer Institute recommended the GFR value within the Calvert formula should not exceed 125 mL/min, thereby capping the carboplatin dose. However, there are studies demonstrating that certain patients’ actual GFR values do exceed 125 mL/min. Therefore, capping the carboplatin dose in these patients may lead to underestimating the carboplatin AUC. A single-center, retrospective study was performed to evaluate the change in platelet count pre- and post-carboplatin exposure in patients with C–G estimated CrCl greater than 125 mL/min receiving capped versus uncapped carboplatin doses. A review of carboplatin dosing strategies is also presented. This study indicated there was a larger mean difference in pre- and post-platelet count in patients receiving uncapped carboplatin compared to patients receiving capped carboplatin with no differences in toxicities. Dose capping this patient population will likely lead to a lower AUC rather than the intended AUC target, which could ultimately lead to substandard outcomes.

Variability of carboplatin dose calculation methods in Spain

Objective To describe and analyze the variability in carboplatin dosing strategies in Spanish hospitals. Methods We designed a questionnaire consisting of 19 multiple-choice items structured in two sections (hospital characteristics and carboplatin dosing data). The questionnaire was sent by e-mail to all the oncology pharmacists included in the register of the Spanish Oncology Pharmacy Group (GEDEFO), and we analyzed the completed questionnaires. Results Response rate was 33.5% from a total of 185 pharmacy services invited to take part in the survey. All hospitals used the Calvert formula to calculate carboplatin dose with glomerular filtration rate estimated by a formula, most commonly the Cockcroft-Gault equation (80.7%). Carboplatin doses were capped in most hospitals (91.9%): 54.8% capped creatinine clearance at 125 mL/min, 11.3% capped serum creatinine, and 19.3% capped both creatinine clearance and serum creatinine. Serum creatinine cut-off values ranged from 0.36 mg/dL to 1 mg/dL. The most commonly used body weight was actual body weight for underweight, normal weight, and overweight patients. The use of adjusted ideal body weight increased in obese and especially in morbidly obese patients. Conclusion The results from this survey show the variability that exists in carboplatin dose calculation methods among Spanish hospitals and the need to continue investigating to find the optimum dose calculation method and unify criteria to avoid differences between sites that can affect effectiveness and toxicity of carboplatin-containing treatments.

Carboplatin dose based on actual renal function: no excess of acute haematotoxicity in adjuvant treatment in seminoma stage I

IntroductionThe practice of carboplatin dosing is not concordant among different centres and oncologists. Some clinical guidelines recommend capping of the carboplatin dose at, for example, creatinine-clearance (Crea-Cl) of 125 mL/min because of concerns of excessive toxicity. Clinical data to support such recommendations are lacking, especially in patients with seminoma.MethodsThis is a retrospective analysis of acute haematotoxicity of patients with stage I seminoma treated with adjuvant carboplatin area under the curve (AUC) 7 in routine practice in two Swiss centres in 2005–2015, and a comparison of incidence and grade (according to Common Terminology Criteria for Adverse Events v4.0) of haematological adverse events (hAEs) in patients with Crea-Cl <125 mL/min vs >125 mL/min without dose capping.Results74 patients with 229 documented measurements were included (median 3/patient). A total of 151 hAEs occurred. Platelet nadir occurred earlier than median white cell/neutrophil count (median day 15 vs day 22; P<0.0001). The majority of hAEs were mild, with more than 80% being of grade 1. Only two (2.7%) clinically relevant hAEs necessitating subsequent interventions occurred (one patient received platelet transfusion, one patient with febrile neutropaenia). Haematological toxicities were not statistically different in patients dosed with Crea-Cl >125 mL/min versus those with Crea-Cl <125 mL/min. No hAEs other than grade 1 occurred before day 10 and after day 24.ConclusionsToxicity after single-dose carboplatin AUC 7 is generally mild. No excess of toxicity occurs in patients with high Crea-Cl above 125 mL/min, and therefore dose capping is not routinely necessary. In addition, this study provides a rationale for efficient use of healthcare services without compromising patients’ safety.

Carboplatin Dosing Accuracy by Estimation of Glomerular Filtration versus Creatinuria in Cancer Patients

Background: The glomerular filtration rate (GFR) is essential for calculating the dose and the monitoring of carboplatin. Although GFR measurement (mGFR) by external markers is ideal, in most cases these are not employed; the most used method is GFR estimation (eGFR) by formulae, hence the need to identify the formula with the best performance. Methods: Patients admitted between 2011 and 2017 and diagnosed with ovarian, endometrial, lung, esophageal, or testicular cancer were assessed retrospectively. The accuracy of the carboplatin dose calculated by creatinine concordance and by the Cockroft-Gault (CG), CKD-EPI, MDRD, Wright, and Jelliffe formulae was assessed using the intraclass correlation coefficient. Results: Fifty-six medical histories were analyzed. The best accuracy was observed between the Wright formula (i.e., 0.71) and the dose calculated based on the 24-h creatinine clearance. Stratification by CKD was made in depurations < 60 mL/min, where the Jelliffe value was excellent (i.e., 0.75). In depurations ≥60 mL/min, CKD-EPI was the best formula, with an accuracy of 0.65. CG was the formula with the worst performance in calculating the dose and glomerular filtration, losing its usefulness with very low filtrations. Conclusions: GFR formulae and calculation of the carboplatin dose have good accuracy with the GFR obtained based on the 24-h creatinine clearance, with the Wright formula being the one with best performance and CG the one with worst performance.