The 6-minute walk test is a good predictor of cardiorespiratory fitness in childhood cancer survivors when access to comprehensive testing is limited.

Cardiovascular disease is up to 10 times more likely among childhood cancer survivors compared to siblings. Low cardiorespiratory fitness is a modifiable risk-factor for cardiovascular diseases. Yet, cardiorespiratory fitness is not routinely screened in pediatric oncology, and healthy VO2max cut-points are unavailable. We aimed to predict cardiorespiratory fitness by developing a simple algorithm and establish cut-points identifying survivors' cardiovascular fitness health-risk zones. We recruited 262 childhood cancer survivors (8-18 years old, ≥1-year posttreatment). Participants completed gold-standard cardiorespiratory fitness assessment (Cardiopulmonary Exercise Test [CPET; VO2max ]) and 6-minute walk test (6MWT). Associations with VO2max were included in a linear regression algorithm to predict VO2max , which was then cross-validated. We used Bland-Altman's limits of agreement and Receiver Operating Characteristic curves using FITNESSGRAM's "Healthy Fitness Zones" to identify cut-points for adequate cardiorespiratory fitness. A total of 199 participants (aged 13.7 ± 2.7 years, 8.5 ± 3.5 years posttreatment) were included. We found a strong positive correlation between VO2max and 6MWT distance (r = 0.61, r2 = 0.37, p < 0.001). Our regression algorithm included 6MWT distance, waist-to-height ratio, age and sex to predict VO2max (r = 0.79, r2 = 0.62, p < 0.001). Forty percentages of predicted VO2max values were within ±3 ml/kg/min of measured VO2max . The cut-point for FITNESSGRAM's "health-risk" fitness zone was 39.8 ml/kg/min (males: AUC = 0.88), and 33.5 ml/kg/min (females: AUC = 0.82). We present an algorithm to reasonably predict cardiorespiratory fitness for childhood cancer survivors, using inexpensive measures. This algorithm has useful clinical application, particularly when CPET is unavailable. Our algorithm has the potential to assist clinicians to identify survivors below the cut-points with increased cardiovascular disease-risk, to monitor and refer for tailored interventions with exercise specialists.

Telehealth application of an ultrasonic home spirometer.

OBJECTIVE: To investigate the validity and home use of a personal ultrasonic spirometer. METHODS: Supervised spirometry was performed using laboratory equipment and a personal ultrasonic spirometer. In addition, the ability of children to perform acceptable spirometry during supervised telehealth appointments at home was assessed. RESULTS: 59 children completed spirometry on both devices. There was high between-device intraclass correlation coefficient (ICC) for forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC): ICC 0.991 (95% CI 0.985 to 0.995) and 0.989 (95% CI 0.981 to 0.993), respectively. Bland-Altman analysis revealed mean bias and limits of agreement of -0.01 (-0.22 to 0.24) L for FEV1 and -0.02 (-0.30 to 0.33) L for FVC. 125 of 140 (89%) supervised telehealth spirometry sessions were acceptable. CONCLUSION: There was excellent reliability in between-device measurements; however, the limits of agreement were wide. Therefore, caution is needed if the device is used interchangeably with laboratory equipment. High success rates of telehealth spirometry sessions indicate the device is suitable for this application.

Long-term morbidity of respiratory viral infections during chemotherapy in children with leukaemia.

BACKGROUND: Respiratory viruses are a common cause of infection in immunosuppressed children undergoing cancer therapy. Pulmonary sequelae have been documented following respiratory viral infections (RVIs) in hematopoietic stem cell transplant (HSCT) recipients; however potential late effects in children undergoing nonmyeloablative chemotherapy have not been investigated. AIM: To evaluate the long-term pulmonary morbidity of respiratory viral infections during chemotherapy in children with acute lymphoblastic leukemia (ALL). METHODS: Childhood ALL survivors, aged 7 to 18 years, greater than 6 months posttreatment were recruited. Exclusion criteria included HSCT or proven bacterial/fungal respiratory infection during treatment. Subjects were classified into "viral" or "control" groups according to retrospective medical records that documented the presence of laboratory-proven RVIs during chemotherapy. Symptom questionnaires (Liverpool, ISAAC) and lung function testing (spirometry, plethysmography, diffusing capacity, forced oscillation technique to ATS/ERS standards) were then performed cross-sectionally at the time of recruitment. RESULTS: Fifty-four patients (31 viral, 23 control) were recruited: median (range) age 11.2 (7.2-18.1) years, and at 4.9 (0.5-13) years posttherapy. Abnormalities were detected in 17 (31%) individuals (8 viral, 9 control), with the most common being DLCO impairment (3 viral, 4 control) and reduced respiratory reactance at 5 Hz (5 viral, 6 control). Children with RVIs during chemotherapy reported more current respiratory symptoms, particularly wheeze (odds ratio [OR], 3.0; 95% confidence interval [CI]: 0.9-10.0; P = .09) and cough (OR, 2.7; 95% CI: 0.8-9.5; P = .11). No differences in lung function tests were observed between the two groups. CONCLUSIONS: Our study found children with RVIs during chemotherapy developed more long-term respiratory symptoms than controls; however, differences did not reach statistical significance. No differences in static lung function were found between the two groups. Overall, pulmonary abnormalities and/or significant ongoing respiratory symptoms were detected in nearly a third of ALL survivors treated without HSCT. Larger, prospective studies are warranted to evaluate the etiology and clinical significance of these findings.