The role of radioactive iodine in the management of patients with differentiated thyroid cancer - An oncologic surgical perspective.

With improved understanding of the biology of differentiated thyroid carcinoma its management is evolving. The approach to surgery for the primary tumour and elective nodal surgery is moving from a "one-size-fits-all" recommendation to a more personalised approach based on risk group stratification. With this selective approach to initial surgery, the indications for adjuvant radioactive iodine (RAI) therapy are also changing. This selective approach to adjuvant therapy requires understanding by the entire treatment team of the rationale for RAI, the potential for benefit, the limitations of the evidence, and the potential for side-effects. This review considers the evidence base for the benefits of using RAI in the primary and recurrent setting as well as the side-effects and risks from RAI treatment. By considering the pros and cons of adjuvant therapy we present an oncologic surgical perspective on selection of treatment for patients, both following pre-operative diagnostic biopsy and in the setting of a post-operative diagnosis of malignancy.

Ethical issues in non-intervention trials for thyroid cancer.

In recent years, the increasing numbers of small, apparently indolent thyroid cancers diagnosed in the world have encouraged investigators to consider non-intervention as an alternative to surgical management. In the following pages, the prospect of a non-intervention trial for thyroid cancer is considered with attention to the ethical issues that such a trial might raise. Such a non-intervention trial is analyzed relative to 7 ethical considerations: the social or scientific value of the research, the scientific validity of the trial, the necessity of fair selection of participants, a favorable risk-benefit ratio for trial participants, independent review of the trial, informed consent, and allowing the study participants to withdraw from the trial. A non-intervention trial for thyroid cancer is also considered relative to the central concept of equipoise.

Pathology-based staging for HPV-positive squamous carcinoma of the oropharynx.

OBJECTIVE: The rapid worldwide rise in incidence of human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) has generated studies confirming this disease as an entity distinct from traditional OPSCC. Based on pathology, surgical studies have revealed prognosticators specific to HPV-positive OPSCC. The current AJCC/UICC staging and pathologic nodal (pN)-classification do not differentiate for survival, demonstrating the need for new, HPV-specific OPSCC staging. The objective of this study was to define a pathologic staging system specific to HPV-positive OPSCC. METHODS: Data were assembled from a surgically-managed, p16-positive OPSCC cohort (any T, any N, M0) of 704 patients from five cancer centers. Analysis was performed for (a) the AJCC/UICC pathologic staging, (b) newly published clinical staging for non-surgically managed HPV-positive OPSCC, and (c) a novel, pathology-based, "HPVpath" staging system that combines features of the primary tumor and nodal metastases. RESULTS: A combination of AJCC/UICC pT-classification and pathology-confirmed metastatic node count (⩽4 versus ⩾5) yielded three groups: stages I (pT1-T2, ⩽4 nodes), II (pT1-T2, ⩾5 nodes; pT3-T4, ⩽4 nodes), and III (pT3-T4, ⩾5 nodes), with incrementally worse prognosis (Kaplan-Meier overall survival of 90%, 84% and 48% respectively). Existing AJCC/UICC pathologic staging lacked prognostic definition. Newly published HPV-specific clinical stagings from non-surgically managed patients, although prognostic, showed lower precision for this surgically managed cohort. CONCLUSIONS: Three loco-regional "HPVpath" stages are identifiable for HPV-positive OPSCC, based on a combination of AJCC/UICC primary tumor pT-classification and metastatic node count. A workable, pathologic staging system is feasible to establish prognosis and guide adjuvant therapy decisions in surgically-managed HPV-positive OPSCC.

The impact of family history on non-medullary thyroid cancer.

INTRODUCTION: Around 10% of patients with non-medullary thyroid cancer (NMTC) will have a positive family history for the disease. Although many will be sporadic, families where 3 first-degree relatives are affected can be considered to represent true familial non-medullary thyroid cancer (FNMTC). The genetic basis, impact on clinical and pathological features, and overall effect on prognosis are poorly understood. METHODS: A literature review identified articles which report on genetic, clinical, therapeutic and screening aspects of FNMTC. The results are presented to allow an understanding of the genetic basis and the impact on clinical-pathological features and prognosis in order to inform clinical decision making. RESULTS: The genetic basis of FNMTC is unknown. Despite this, significant progress has been made in identifying potential susceptibility genes. The lack of a test for FNMTC has led to a clinical definition requiring a minimum of 3 first-degree relatives to be diagnosed with NMTC. Although some have shown an association with multi-centric disease, younger age and increased rates of extra-thyroidal extension and nodal metastases, these findings are not supported by all. The impact of FNMTC is unclear with all groups reporting good outcome, and some finding an association with more aggressive disease. The role of screening remains controversial. CONCLUSION: FNMTC is rare but can be diagnosed clinically. Its impact on prognostic factors and the subsequent role in influencing management is debated. For those patients who present with otherwise low-risk differentiated thyroid cancer, FNMTC should be included in risk assessment when discussing therapeutic options.

Outcomes for patients with papillary thyroid cancer who do not undergo prophylactic central neck dissection.

BACKGROUND: The role of prophylactic central neck dissection (CND) in the management of papillary thyroid cancer (PTC) is controversial. This report describes outcomes of an observational approach in patients without clinical evidence of nodal disease in PTC. METHODS: All patients who had surgery between 1986 and 2010 without CND for PTC were identified. All patients had careful clinical assessment of the central neck during preoperative and perioperative evaluation, with any suspicious nodal tissue excised for analysis. The cohort included patients in whom lymph nodes had been removed, but no patient had undergone a formal neck dissection. Recurrence-free survival (RFS), central neck RFS and disease-specific survival (DSS) were calculated using the Kaplan-Meier method. RESULTS: Of 1798 patients, 397 (22.1 per cent) were men, 1088 (60.5 per cent) were aged 45 years or more, and 539 (30.0 per cent) had pT3 or pT4 disease. Some 742 patients (41.3 per cent) received adjuvant treatment with radioactive iodine. At a median follow-up of 46 months the 5-year DSS rate was 100 per cent. Five-year RFS and central neck RFS rates were 96.6 and 99.1 per cent respectively. CONCLUSION: Observation of the central neck is safe and should be recommended for all patients with PTC considered before and during surgery to be free of central neck metastasis.

Prognostic Performance of Current Stage III Oral Cancer Patients After Curative Intent Resection: Evidence to Support a Revision of the American Joint Committee on Cancer Staging System.

BACKGROUND: The American Joint Committee on Cancer (AJCC) stage III classification of oral cavity squamous cell carcinoma (OCSCC) represents a heterogeneous group of patients with early local disease with regional metastases (T1N1 and T2N1) and advanced local disease with or without regional metastasis (T3N0 and T3N1). OBJECTIVE: The aim of this study was to evaluate prognostic heterogeneity in the stage III category. METHODS AND PATIENTS: An international retrospective multicenter study of 1815 patients who were treated for OCSCC from 2003 to 2011. RESULTS: Kaplan-Meier survival analysis and multivariate models of stage III patients revealed better overall survival (OS; HR 2.12, 95 % CI 1.03-4.15; p = 0.01) and disease-specific survival (DSS; HR 1.7, 95 % CI 1.16-4.12; p = 0.04) rates for patients with T1-2N1/T3N0 disease than for patients with T3N1 disease. The outcomes of patients with T3N1 and stage IVa disease were similar (p = 0.89 and p = 0.78 for OS and DSS, respectively). Modifying stage classification by transferring the T3N1 category to the stage VIa group resulted in a better prognostic performance [Harrell's concordance index, C index 0.76; Akaike's Information Criterion (AIC) 4131.6] compared with the AJCC 7th edition staging system (C index 0.65; AIC 4144.9) for OS. When DSS was assessed, the suggested staging system remained the best performing model (C index 0.71; AIC 1061.3) compared with the current AJCC 7th edition staging (C index 0.64; AIC 1066.2). CONCLUSIONS: The prognosis of T3N1 and stage IVa disease are similar in OCSCC, suggesting that these categories could be combined in future revisions of the nodal staging system to enhance prognostic accuracy.

Outcomes in patients with poorly differentiated thyroid carcinoma.

BACKGROUND: Poorly differentiated thyroid cancer (PDTC) accounts for only 1-15% of all thyroid cancers. Our objective is to report outcomes in a large series of patients with PDTC treated at a single tertiary care cancer center. METHODS: A total of 91 patients with primary PDTC were treated by initial surgery with or without adjuvant therapy at Memorial Sloan-Kettering Cancer Center from 1986 to 2009. Outcomes were calculated by the Kaplan-Meier method. Clinicopathological characteristics were compared for PDTC patients who died of disease to those who did not by the χ(2) test. Factors predictive of disease-specific survival (DSS) were calculated by univariate and multivariate analysis using the log rank and Cox proportional hazards method, respectively. RESULTS: With a median follow-up of 50 months, the 5-year overall survival and DSS were 62 and 66%, respectively. The 5-year locoregional and distant control were 81 and 59%, respectively. Of 27 disease-specific deaths, 23 (85%) were due to distant disease. Age ≥ 45 years, pathological tumor size >4 cm, extrathyroidal extension, higher pathological T stage, positive margins, and distant metastases (M1) were predictive of worse DSS on univariate analysis. Multivariate analysis showed that only pT4a stage and M1 were independent predictors of worse DSS. CONCLUSIONS: With appropriate surgery and adjuvant therapy, excellent locoregional control can be achieved in PDTC. Disease-specific deaths occurred due to distant metastases and rarely due to uncontrolled locoregional recurrence in this series.

Anaplastic thyroid carcinoma: a 25-year single-institution experience.

BACKGROUND: Anaplastic thyroid carcinoma (ATC) is among the most aggressive solid tumors accounting for 1-5 % of primary thyroid malignancies. In this retrospective review, we aim to evaluate the prognostic factors, treatment approaches, and outcomes of patients with ATC treated at a single institution. MATERIALS AND METHODS: We retrospectively identified 95 patients with ATC from an institutional database between 1985 and 2010. A total of 83 patients with sufficient records were included in this study. Patient, tumor, and treatment characteristics were recorded. Disease-specific survival (DSS) was determined by the Kaplan-Meier method, and factors predictive of outcome were determined by univariate and multivariate analysis. RESULTS: Of the 83 patients, 41 were male and 42 were female. The median age at presentation was 60 years (range 28-89 years) with a median survival of 8 months. The 1- and 2-year DSS were 33 and 23 %, respectively. On univariate analysis, age less than 60 years, clinically N0 neck, absence of clinical extrathyroidal extension (cETE), gross total resection, and multimodality treatment were statistically significant predictors of improved survival. On multivariate analysis, absence of cETE, multimodality therapy, and gross total resection were predictors of improved outcome. CONCLUSIONS: In patients with locoregional limited disease, multimodality treatment with gross total surgical resection and postoperative radiotherapy with or without chemotherapy offers the best local control and DSS.

Incidence and location of positive nonsentinel lymph nodes in head and neck melanoma.

BACKGROUND: The complex lymphatic drainage in the head and neck makes sentinel lymph node biopsy (SLNB) for melanomas in this region challenging. This study describes the incidence, and location of additional positive nonsentinel lymph nodes (NSLN) in patients with cutaneous head and neck melanoma following a positive SLNB. METHODS: A retrospective review was performed using a single institution prospective database. Patients with a primary melanoma in the head or neck with a positive cervical SLNB were identified. The lymphadenectomy specimen was divided intraoperatively into lymph node levels I-V, and NSLN status determined for each level. RESULTS: Of 387 patients with melanoma of the head and neck who underwent cervical SLNB, 54 had a positive SLN identified (14%). Thirty six patients (67%) underwent immediate completion lymph node dissection (CLND) of whom eight patients (22%) had a positive NSLN. The remaining 18 patients (33%) did not undergo CLND and were observed. Half of positive NSLNs (50%) were in the same lymph node level as the SLN and 33% were in an immediately adjacent level; only two patients were found to have NSLNs in non-adjacent levels. The only factor predictive of NSLN involvement was the size of the tumor deposit in the SLN>0.2 mm (p = 0.05). Superficial parotidectomy at CLND revealed metastatic melanoma only in patients with a positive parotid SLN. CONCLUSIONS: A positive NLSN was identified in 22% of patients undergoing CLND after a positive SLNB. The majority of positive NSLNs are found within or immediately adjacent to the nodal level containing the SLN.

Lymph node density in oral cavity cancer: results of the International Consortium for Outcomes Research.

BACKGROUND: Lymph node density (LND) has previously been reported to reliably predict recurrence risk and survival in oral cavity squamous cell carcinoma (OSCC). This multicenter international study was designed to validate the concept of LND in OSCC. METHODS: The study included 4254 patients diagnosed as having OSCC. The median follow-up was 41 months. Five-year overall survival (OS), disease-specific survival (DSS), disease-free survival (DFS), locoregional control and distant metastasis rates were calculated using the Kaplan-Meier method. Lymph node density (number of positive lymph nodes/total number of excised lymph nodes) was subjected to multivariate analysis. RESULTS: The OS was 49% for patients with LND0.07 compared with 35% for patients with LND>0.07 (P<0.001). Similarly, the DSS was 60% for patients with LND0.07 compared with 41% for those with LND>0.07 (P<0.001). Lymph node density reliably stratified patients according to their risk of failure within the individual N subgroups (P=0.03). A modified TNM staging system based on LND ratio was consistently superior to the traditional system in estimating survival measures. CONCLUSION: This multi-institutional study validates the reliability and applicability of LND as a predictor of outcomes in OSCC. Lymph node density can potentially assist in identifying patients with poor outcomes and therefore for whom more aggressive adjuvant treatment is needed.

Clinical nodal stage is a significant predictor of outcome in patients with oral cavity squamous cell carcinoma and pathologically negative neck metastases: results of the international consortium for outcome research.

BACKGROUND: We aimed to study the importance of clinical N classification (cN) in a subgroup of patients with oral cavity squamous cell carcinoma (OSCC) and pathologically negative neck nodes (pN-). METHODS: A total of 2,258 patients from 11 cancer centers who underwent neck dissection for OSCC (1990-2011) had pN- disease. The median follow-up was 44 months. 5-year overall survival (OS), disease-specific survival (DSS), disease free survival, local control, locoregional control, and distant metastasis rates were calculated by the Kaplan-Meier method. cN classification and tumor, node, metastasis classification system staging variables were subjected to multivariate analysis. RESULTS: A total of 345 patients were preoperatively classified as cN+ and 1,913 were classified as cN-. The 5-year OS and DSS of cN- patients were 73.6 and 82.2 %, respectively. The 5-year OS and DSS of cN+ patients were 64.9 and 76.9 %, respectively (p < 0.0001 each). A cN+ classification was a significant predictor of worse OS (p = 0.03) and DSS (p = 0.016), regardless of treatment, depth of invasion, or extent of neck dissection. cN classification was associated with recurrence-free survival (p = 0.01) and locoregional (neck and primary tumor) control (p = 0.004), but not with local (p = 0.19) and distant (p = 0.06) recurrence rates. CONCLUSIONS: Clinical evidence of neck metastases is an independent predictor of outcome, even in patients with pN- nodes.

Thyroid cancer: surgery for the primary tumor.

Surgery is the mainstay of therapy for most patients who present with thyroid cancer. The surgeon must select an appropriate procedure based upon pre operative factors such as tumor histology, extent of primary disease, the presence of regional or distant metastases, associated disease in the contralateral thyroid lobe and the potential for post operative adjuvant therapy. Preservation of the vital structures in the central neck, including the recurrent and superior laryngeal nerves and the parathyroid glands is critical as is the maintenance of absolute hemostasis. In this review article we describe the management of Well Differentiated Thyroid Cancer (WDTC) presenting as a solitary nodule, WDTC in a background of multinodular disease and the management of WDTC presenting as advanced local disease. We go onto discuss the impact that regional and distant metastases have on the choice of surgical approach. The focus of this article is WDTC, however the principles of management of the primary in medullary and anaplastic carcinoma are also discussed.

The role of sentinel lymph node biopsy in the management of head and neck desmoplastic melanoma.

BACKGROUND: Desmoplastic melanoma (DM), a variant of spindle cell melanoma, has a higher propensity for local recurrence and a lower incidence of nodal metastasis. In this retrospective review, we evaluated the risk for regional nodal metastases and the need for sentinel lymph node biopsy (SLNB) in patients with head and neck DM. METHODS: We identified 103 patients with DM from an institutional database of patients with head and neck melanomas treated between 1985 and 2009. Forty-seven patients had their primary treatment at Memorial Sloan-Kettering Cancer Center, and 56 patients were treated for recurrent or metastatic disease. RESULTS: Of the 47 study patients, 27 were men and 20 were women with a median age of 71 years. All patients underwent wide excision, and 21 (44 %) underwent SLNB. None of the patients who underwent SLNB had positive nodes. The mean Breslow thickness for the 45 reported patients was 6.1 mm, with 84 % of tumors >2 mm in thickness and 55 % >4 mm. All known Clark thickness levels (n = 40) were IV or V. The overall survival was 73 %, with disease-specific survival of 84 %, local recurrence-free survival of 75 %, and neck recurrence-free survival of 97 % at 5 years. CONCLUSIONS: Although DM is diagnosed at higher Breslow thickness and Clark level, neck metastases are rare and prognosis is favorable compared to conventional melanoma. The low incidence of lymphovascular invasion, high frequency of histopathologically negative sentinel lymph nodes, and low neck recurrence rates indicate that staging of neck disease by SLNB is not necessary in patients with pure DM of the head and neck.

Sensitivity analysis for liver iron measurement through neutron stimulated emission computed tomography: a Monte Carlo study in GEANT4.

Neutron stimulated emission computed tomography (NSECT) is being developed as a non-invasive imaging modality to detect and quantify iron overload in the human liver. NSECT uses gamma photons emitted by the inelastic interaction between monochromatic fast neutrons and iron nuclei in the body to detect and quantify the disease. Previous simulated and physical experiments with phantoms have shown that NSECT has the potential to accurately diagnose iron overload with reasonable levels of radiation dose. In this work, we describe the results of a simulation study conducted to determine the sensitivity of the NSECT system for hepatic iron quantification in patients of different sizes. A GEANT4 simulation of the NSECT system was developed with a human liver and two torso sizes corresponding to small and large patients. The iron concentration in the liver ranged between 0.5 and 20 mg g(-1), corresponding to clinically reported iron levels in iron-overloaded patients. High-purity germanium gamma detectors were simulated to detect the emitted gamma spectra, which were background corrected using suitable water phantoms and analyzed to determine the minimum detectable level (MDL) of iron and the sensitivity of the NSECT system. These analyses indicate that for a small patient (torso major axis = 30 cm) the MDL is 0.5 mg g(-1) and sensitivity is ∼13 ± 2 Fe counts/mg/mSv and for a large patient (torso major axis = 40 cm) the values are 1 mg g(-1) and ∼5 ± 1 Fe counts/mg/mSv, respectively. The results demonstrate that the MDL for both patient sizes lies within the clinically significant range for human iron overload.

SU-E-I-02: Size-Dependent Computed Tomography Histogram Analysis: Towards Breast Tissue Segmentation.

PURPOSE: To examine the effects of object size on scatter-corrected CT histograms to be used in threshold-based tissue segmentation. METHODS: A polyethylene cone filled with various concentrations of water and methanol mixtures, simulating glandular and adipose tissues, were imaged with our quasi-monochromatic dedicated breast CT, and scatter corrected using beam-stop array measurements. Images were reconstructed using iterative OSC, and individual coronal slices along the central axis of the cone were analyzed, with radii ranging from 3.25-6.25cm. Histograms from each slice were fit with two Gaussians (fluid filling and cone material) using nonlinear least squares methods, and the corresponding standard deviation and peak centroid of each filled material were evaluated as a function of object radius. Identical methods were applied to dedicated breast CT images of four patients for clinical comparison. RESULTS: Analysis of phantoms and breast data indicates low correlation between the standard deviation and object diameter. The centroids of the Gaussian peaks demonstrate an inverse linear relationship with increasing object size, independent of object material. The clinical datasets show a similar linear relationship between centroids and breast radius. CONCLUSIONS: Data indicate that using a linear combination of Gaussian distribution functions to segment breast tissue in scatter corrected, quasi-monochromatic cone beam dedicated breast CT is possible. An object size-independent variation of attenuation values may allow for consistent restraints on initial fit parameters, resulting in improved confidence using Gaussian curve fitting. Appropriate scaling of the size-dependent volume slices, or independent slice analysis, is necessary to minimize binning variability for accurate tissue segmentation using Gaussian curve fitting. This work is supported by National Institutes of Health (R01-CA096821) and NIH Training Grant (T32-EB007185). MPT is the inventor of this hybrid breast imaging technology, and is named as an inventor on the patent for this technology assigned to Duke (US Pat. #7,609,808). If this technology becomes commercially successful, MPT and Duke could benefit financially.

Parathyroid carcinoma.

Parathyroid carcinoma is a rare endocrine malignancy. The reported incidence is from 0.5 to 5% of primary hyperparathyroidism cases in various series. The cause is unknown, but clinical correlations with different genetic syndromes exist. Mutations in the HPRT2 gene seem to play a significant role in the pathogenesis of this disease. Men and women are equally affected, usually in the fourth or fifth decade of life. Most patients will present with signs and symptoms of hypercalcaemia. Cases of non-functioning carcinoma are exceedingly rare. Surgical resection is the most effective method of treatment and palliation. A significant proportion of patients will experience recurrence, and will need further surgical and, eventually, medical management of hypercalcaemia. The disease is progressive but slow growing. Most patients will require multiple operations to resect recurrent disease. The main cause of morbidity and mortality is the sequela of uncontrolled chronic hypercalcaemia rather than tumour burden. The current paper will review the epidemiology, pathogenesis, clinical presentation and diagnostic work-up of this disease. Surgical management in different scenarios is reviewed in detail, followed by other types of treatment and management of incurable disease.

Stage IA vs. IB endometrial stromal sarcoma: does the new staging system predict survival?

OBJECTIVE: To determine the correlation of the new FIGO staging system with survival in stage I patients with low-grade and high-grade endometrial stromal sarcomas. METHODS: Data were extracted from the Surveillance, Epidemiology, and End Results database between 1988 and 2005. Kaplan-Meier log rank and Cox proportional hazards models were used for survival analysis and to identify possible predictors for survival. RESULTS: The identified cohort included 464 women, 310 (67%) low-grade endometrial stromal sarcoma, 96 (21%) high-grade endometrial stromal sarcoma, and 58 (12%) unclassified endometrial stromal sarcoma. Among low-grade and high-grade endometrial stromal sarcomas, there was no significant demographic or clinico-pathologic difference between stages IA and IB. The 5-year overall survival was worse in high-grade endometrial stromal sarcoma than low-grade endometrial stromal sarcoma (45.4% vs. 97.2%, p<0.001). The difference in 5-year overall survival among women with low-grade endometrial stromal sarcoma between stages IA and IB was significant (100% vs. 93.5%, p=0.003), but not among women with high-grade endometrial stromal sarcoma (51.4% vs. 43.5%, p=0.27). Although age (p=0.001), race (p=0.005), and stage (p=0.004) were all significant prognostic factors in low-grade endometrial stromal sarcoma, only cervical involvement (p=0.02) was a significant predictor in high-grade endometrial stromal sarcoma. CONCLUSION: The new staging system is appropriate for risk stratification in low-grade endometrial stromal sarcoma. The prognosis in high-grade endometrial stromal sarcoma seems to be most influenced by the presence of cervical involvement and not by tumor size as the staging criteria would suggest.

Continuous negative extrathoracic pressure or continuous positive airway pressure for acute hypoxemic respiratory failure in children.

BACKGROUND: Acute hypoxemic respiratory failure (AHRF) is an important cause of mortality and morbidity in children. Positive pressure ventilation is currently the standard care, however, it does have complications. Continuous negative extrathoracic pressure ventilation (CNEP) or continuous positive airway pressure (CPAP) ventilation delivered via non-invasive approaches (Ni-CPAP) have shown certain beneficial effects in animal and uncontrolled human studies. OBJECTIVES: The primary objective was to assess the effectiveness of CNEP or Ni-CPAP in pediatric patients with AHRF from non-cardiogenic causes. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2007, Issue 3); MEDLINE (January 1966 to July 2007); EMBASE (1980 to July 2007); CINAHL (1982 to July 2007); and published abstracts from the meetings of the American Thoracic Society and Pediatric Critical Care Meetings (1992 to 2007). SELECTION CRITERIA: Randomized or quasi-randomized clinical trials of either CNEP or Ni-CPAP versus standard therapy (including positive pressure ventilation) involving children (at least 1 month old and less than 18 years of age at the time of randomization) who met the criteria for diagnosis of AHRF with at least one of the outcomes reported were included. DATA COLLECTION AND ANALYSIS: Risks of bias of the included study was assessed using: concealment of allocation, blinding of intervention, completeness of follow up and blinding of outcome measurements. Data on relevant outcomes were abstracted and the effect size was estimated by calculating relative risk (RR) with 95% confidence intervals (CI) and risk difference (RD). MAIN RESULTS: One eligible study published in an abstract format was identified. It studied 33 infants (18 controls, 15 receiving CNEP) with a clinical diagnosis of bronchiolitis and fraction of inspired oxygen (FiO(2)) > 40% were studied. This allowed a reduction in the FiO(2) (< 30% within one hour of initiation of therapy) in four patients in the CNEP group compared to none in the control group (RR 10.7, 95% CI 0.6 to 183.9). One infant required CPAP and one infant required nasal CPAP in the control group while all infants in the CNEP group were managed without intubation (RR for both outcomes 0.40, 95% CI 0.02 to 9.06). AUTHORS' CONCLUSIONS: There is a lack of well designed, controlled experiments of non-invasive modes of respiratory support in children with AHRF. Reduction of in-hospital mortality is an important outcome and even a small reduction would be beneficial. Studies assessing other outcomes such as avoidance of intubation and its associated complications, reduction in hospital stay and improvement in patient comfort are also valuable in gauging the overall impact of these strategies.