Kristin R Knight

Great Ormond Street Hospital for Children NHS Foundation Trust, Londinium, England, United Kingdom

Are you Kristin R Knight?

Claim your profile

Publications (6)78.98 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Purpose The platinum chemotherapy agents cisplatin and carboplatin are widely used in the treatment of adult and pediatric cancers. Cisplatin causes hearing loss in at least 60% of pediatric patients. Reducing cisplatin and high-dose carboplatin ototoxicity without reducing efficacy is important. Patients and Methods This review summarizes recommendations made at the 42nd Congress of the International Society of Pediatric Oncology (SIOP) in Boston, October 21-24, 2010, reflecting input from international basic scientists, pediatric oncologists, otolaryngologists, oncology nurses, audiolo-gists, and neurosurgeons to develop and advance research and clinical trials for otoprotection. Results Platinum initially impairs hearing in the high frequencies and progresses to lower frequencies with increasing cumulative dose. Genes involved in drug transport, metabolism, and DNA repair regulate platinum toxicities. Otoprotection can be achieved by acting on several these pathways and generally involves antioxidant thiol agents. Otoprotection is a strategy being explored to decrease hearing loss while maintaining dose intensity or allowing dose escalation, but it has the potential to interfere with tumoricidal effects. Route of administration and optimal timing relative to platinum therapy are critical issues. In addition, international standards for grading and comparing ototoxicity are essential to the success of prospective pediatric trials aimed at reducing platinum-induced hearing loss. Conclusion Collaborative prospective basic and clinical trial research is needed to reduce the incidence of irreversible platinum-induced hearing loss, and optimize cancer control. Wide use of the new internationally agreed-on SIOP Boston ototoxicity scale in current and future otoprotection trials should help facilitate this goal.
    Journal of Clinical Oncology 07/2012; 30(19):2408-2417. · 18.04 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The platinum chemotherapy agents cisplatin and carboplatin are widely used in the treatment of adult and pediatric cancers. Cisplatin causes hearing loss in at least 60% of pediatric patients. Reducing cisplatin and high-dose carboplatin ototoxicity without reducing efficacy is important. This review summarizes recommendations made at the 42nd Congress of the International Society of Pediatric Oncology (SIOP) in Boston, October 21-24, 2010, reflecting input from international basic scientists, pediatric oncologists, otolaryngologists, oncology nurses, audiologists, and neurosurgeons to develop and advance research and clinical trials for otoprotection. Platinum initially impairs hearing in the high frequencies and progresses to lower frequencies with increasing cumulative dose. Genes involved in drug transport, metabolism, and DNA repair regulate platinum toxicities. Otoprotection can be achieved by acting on several these pathways and generally involves antioxidant thiol agents. Otoprotection is a strategy being explored to decrease hearing loss while maintaining dose intensity or allowing dose escalation, but it has the potential to interfere with tumoricidal effects. Route of administration and optimal timing relative to platinum therapy are critical issues. In addition, international standards for grading and comparing ototoxicity are essential to the success of prospective pediatric trials aimed at reducing platinum-induced hearing loss. Collaborative prospective basic and clinical trial research is needed to reduce the incidence of irreversible platinum-induced hearing loss, and optimize cancer control. Wide use of the new internationally agreed-on SIOP Boston ototoxicity scale in current and future otoprotection trials should help facilitate this goal.
    Journal of Clinical Oncology 04/2012; 30(19):2408-17. · 18.04 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cerebrospinal fluid shunting has previously been associated with hearing loss. Although the mechanism for this is unclear, it is thought that changes in CSF pressure can affect cochlear physiology via endolymph expansion in the setting of a patent cochlear aqueduct. Patients undergoing radiation and cisplatin chemotherapy are at risk for hearing loss. The authors hypothesized that the incidence and severity of hearing loss in patients undergoing radiation and chemotherapy for medulloblastoma would be greater in those with shunts than in those without shunts. Baseline and longitudinal audiology data were collected in 33 patients with medulloblastoma who were receiving radiation and cisplatin chemotherapy. Additional data included age, sex, details of shunt placement and revision, and details of chemotherapy and radiation. Hearing sensitivity and peripheral auditory function measures included pure tone audiometry, immittance audiometry, and distortion product evoked otoacoustic emissions. Ototoxicity was determined according to the American Speech-Language-Hearing Association criteria. Severity of hearing loss was determined using the Brock hearing loss grades. Incidence of hearing loss and association with shunting was determined. Thirteen (39.4%) of the 33 patients evaluated had undergone shunt placement. Hearing loss occurred in 14 (70%) of 20 patients without shunts and in 13 (100%) of 13 patients with shunts. The difference between the rates of hearing loss in patients with shunts versus those without the devices was highly significant (p = 0.0008). The odds ratio for hearing loss in patients with a CSF shunt compared with those without a shunt was 23.49 (95% CI 4.21-131.15). Age, side of shunt, evidence of dissemination, diameter of cochlear aqueduct, and treatment protocol did not have a significant effect on shunt-related ototoxicity. This study suggests an independent association between CSF shunting and hearing loss in children undergoing treatment for medulloblastoma, laying the foundation for a prospective study evaluating hearing loss in children with shunts who are not treated with ototoxic therapy.
    Journal of Neurosurgery Pediatrics 04/2012; 9(4):421-7. · 1.63 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND.The rate of durable responses in embryonal and certain germ cell tumors of the central nervous system (CNS) is unsatisfactory. Intraarterial chemotherapy and osmotic blood-brain barrier disruption (IA/BBBD) increases drug delivery to the CNS.METHODS.Data of patients treated with carboplatin or methotrexate-based IA/BBBD on prospective phase 2 trials conducted at 3 centers were collected. Study outcomes included overall survival (OS), time to progression (TTP), and toxicity.RESULTS.Fifty-four patients were treated. Twenty-seven patients received IA/BBBD as salvage treatment. The median OS was 2.8 years for all patients, 2.5 years for supratentorial and disseminated primitive neuroectodermal tumors (PNETs, n = 29), 1.7 years for medulloblastomas (n = 12), and 5.4 years for germ cell tumors (n = 13). OS and TTP for all patients were better with a Karnofsky Performance Status ≥70% (P = .0013 and .0070) and IA/BBBD as first-line treatment (P = .0059 and .029). In PNETs, OS was higher with pineal location (P = .045) and IA/BBBD as first-line treatment (P = .0036), and TTP was improved with radiotherapy before IA/BBBD (P = .036) and IA/BBBD as first-line treatment (P = .0079). Seventeen of 54 patients (31%) are alive, and 16 are alive at 4+ to 18+ years. Three survivors were not treated with radiotherapy and 4 were treated with focal radiotherapy only. The patients who were not irradiated did not develop dementia.CONCLUSIONS.Survival and toxicity data appear promising, considering the cohort's adverse prognostic profile. A plateau in survival curves suggests a cure for some patients. Long-term survival may be achieved with focal or reduced-dose radiotherapy in some IA/BBBD patients. Cancer 2008. © 2007 American Cancer Society.
    Cancer 01/2008; 112(3):581 - 588. · 5.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The objective is to describe progressive changes in hearing and cochlear function in children and adolescents treated with platinum-based chemotherapy and to begin preliminary evaluation of the feasibility of extended high-frequency audiometry and distortion product otoacoustic emissions for ototoxicity monitoring in children. Baseline and serial measurement of conventional pure-tone audiometry (0.5 to 8 kHz) and evoked distortion product otoacoustic emissions (DPOAEs) were conducted for 32 patients age 8 months to 20 years who were treated with cisplatin and/or carboplatin chemotherapy. Seventeen children also had baseline and serial measurement of extended high-frequency (EHF) audiometry (9 to 16 kHz). Audiologic data were analyzed to determine the incidence of ototoxicity using the American Speech-Language-Hearing Association criteria, and the relationships between the different measures of ototoxicity. Of the 32 children, 20 (62.5%) acquired bilateral ototoxicity in the conventional frequency range during chemotherapy treatment, and 26 (81.3%) had bilateral decreases in DPOAE amplitudes and dynamic range. Of the 17 children with EHF audiometry results, 16 (94.1%) had bilateral ototoxicity in the EHF range. Pilot data suggest that EHF thresholds and DPOAEs show ototoxic changes before hearing loss is detected by conventional audiometry. EHF audiometry and DPOAEs have the potential to reveal earlier changes in auditory function than conventional frequency audiometry during platinum chemotherapy in children.
    Journal of Clinical Oncology 04/2007; 25(10):1190-5. · 18.04 Impact Factor
  • Kristin R Gilmer Knight, Dale F Kraemer, Edward A Neuwelt
    [Show abstract] [Hide abstract]
    ABSTRACT: To describe the frequency and severity of ototoxicity in a series of pediatric patients treated with platinum-based chemotherapy. Serial audiologic evaluations were conducted for 67 patients aged 8 months to 23 years who received platinum-based chemotherapy. Audiologic data was analyzed to determine time to hearing-loss using American Speech-Language-Hearing Association (ASHA) criteria, and the effects of treatment and patient characteristics on the incidence and severity of ototoxicity. Bilateral decreases in hearing were seen in 61% of patients (median time to hearing loss, 135 days). Children treated for medulloblastoma, osteosarcoma, and neuroblastoma had greater incidence and severity of hearing loss. Agreement between the usually reported National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) and ASHA criteria was inadequate. Traditional reporting of toxicity data (CTCAE) has under-reported ototoxicity and minimized the significance of hearing loss in children. As pediatric patients experience improved survival, the effects and implications of high-frequency hearing loss with regard to academic achievement and speech and language development are important considerations, especially in patients younger than 5 years.
    Journal of Clinical Oncology 01/2006; 23(34):8588-96. · 18.04 Impact Factor

Publication Stats

185 Citations
78.98 Total Impact Points

Institutions

  • 2012
    • Great Ormond Street Hospital for Children NHS Foundation Trust
      Londinium, England, United Kingdom
  • 2006–2012
    • Oregon Health and Science University
      • • Department of Neurological Surgery
      • • Department of Neurology
      Portland, OR, United States