Comparison of methods for estimating glomerular filtration rate in head and neck cancer patients treated with cisplatin.

Cisplatin is a chemotherapeutic agent widely used in the treatment of various solid tumors. Cisplatin induces nephrotoxicity and may lead to long-term reduction of kidney function. Consequently, determination of glomerular filtration rate (GFR) is used to monitor potential kidney damage. This study aimed to compare two commonly used algorithms for estimating GFR (eGFR) from plasma creatinine (PCr) with 51Cr-EDTA clearance (CrCl) as a reference method. This was a retrospective single center study of 94 head and neck cancer patients treated with cisplatin. CrCl was performed once before, during, and after treatment, and PCr was measured concurrently. eGFR was assessed from PCr applying the Cockcroft-Gault (CG) and the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equations. Agreement was assessed applying the statistical methods of Bland and Altman. A predefined limit of clinically acceptable variation between CrCl and eGFR of 14% was applied. Comparison of CrCl and eGFRCKD revealed a positive slope of the linear regression line, suggesting proportional bias (p < 0.001). No systematic bias was found for eGFRCG. Pre-treatment, 42 (46%), 53 (56%) and 48 (53%) observations were within the clinically acceptable limit of variation for standardized eGFRCKD, BSA corrected eGFRCKD, and eGFRCG, respectively. The observed body weight changes were significant. In conclusion, estimated GFRCKD cannot sufficiently replace CrCl in the assessment of GFR during treatment with cisplatin due to systematic bias. Consequently, if CrCl is unavailable, then the CG equation is the better choice provided proper attention is paid to the large variation between methods.

Autonomic nervous system activity in primary Raynaud's phenomenon: Heart rate variability, plasma catecholamines and [123 I]MIBG heart scintigraphy.

BACKGROUND AND AIM: Primary Raynaud's phenomenon (pRP) is characterized by an exaggerated response to cold, resulting in the whitening typically of the fingers and toes. The patients are generally perceived as healthy individuals with a benign condition. However, the condition has been associated with increased cardiovascular mortality and changes in autonomic nervous system activity. This study aimed to investigate whether pRP is associated with pervasive changes in autonomic nervous activity. The hypothesis was that patients with pRP have increased sympathetic nervous activity. METHODS: The autonomic nervous activity of 22 patients with pRP was investigated by means of heart rate variability (HRV) and the plasma catecholamine response to head-up tilt and compared with 22 age- and gender-matched controls. In addition, the patients were examined with a [123 I]metaiodobenzylguanidine heart scintigraphy and compared with an external control group. RESULTS: The plasma norepinephrine response to head-up tilt was significantly lower in the patient group than in the control group. Similarly, the heart scintigraphy revealed a lower heart-to-mediastinum ratio in the patient group than in the control group. HRV analysis did not reveal significant differences between the groups. CONCLUSION: The findings of the study showed that the autonomic nervous activity of patients with pRP was altered compared with the activity of healthy individuals. This was observed both during rest and after positional stress, but the findings did not uniformly concur with our initial hypothesis.

Characteristic Features of Infrared Thermographic Imaging in Primary Raynaud's Phenomenon.

Raynaud's phenomenon (RP) is characterized by the episodic whitening of the fingers upon exposure to cold. Verification of the condition is crucial in vibration-exposed patients. The current verification method is outdated, but thermographic imaging seems promising as a diagnostic replacement. By investigating patients diagnosed with RP, the study aimed at developing a simple thermographic procedure that could be applied to future patients where verification of the diagnosis is needed. Twenty-two patients with primary RP and 58 healthy controls were examined using thermographic imaging after local cooling of the hands for 1 min in water of 10°C. A logistic regression model was fitted with the temperature curve characteristics to convey a predicted probability of having RP. The characteristics time to end temperature and baseline temperature were the most appropriate predictors of RP among those examined (p = 0.004 and p = 0.04, respectively). The area under the curve was 0.91. The cut-off level 0.46 yielded a sensitivity and specificity of 82% and 86%, respectively. The positive and negative predictive values were 69% and 93%, respectively. This newly developed thermographic method was able to distinguish between patients with RP and healthy controls and was easy to operate. Thus, the method showed great promise as a method for verification of RP in future patients. Trial registration: ClinicalTrials.gov NCT03094910.

Infrared Thermography as a Method of Verification in Raynaud's Phenomenon.

Raynaud's phenomenon (RP) is characterized by the episodic whitening of the fingers upon exposure to cold. A recently described thermographic algorithm was proposed as a diagnostic replacement of the currently applied finger systolic pressure (FSP) test. The aim of the study was to evaluate the performance of the thermographic algorithm when applied in patients suspected of having RP. Forty-three patients were examined using thermographic imaging after local cooling of the hands in water of 10 °C for 1 min. The thermographic algorithm was applied to predict the probability of RP. The performance of the algorithm was evaluated with different cut-off levels. A new algorithm was proposed based on patients from the target population. The performance of the tested algorithm was noninferior to the FSP test, when a cut-off level of 0.05 was applied, yielding a sensitivity and specificity of 69% and 58%, respectively. The accuracy was 66%. The FSP test had a sensitivity and specificity of 77% and 37%, respectively, and the accuracy was 59%. The thermographic method proved useful for detecting RP and was able to replace the FSP test as a diagnostic test. The alternative algorithm revealed that other thermographic variables were more predictive of the target population, but this should be verified in future patients.

The Nephroprotective Effect of Mannitol in Head and Neck Cancer Patients Receiving Cisplatin Therapy.

INTRODUCTION: Cisplatin is used as treatment for several different malignancies and a well-known complication is irreversible kidney damage. To protect the kidneys, this treatment is often combined with mannitol infusion to promote osmotic diuresis. Earlier studies investigating the nephroprotective effect of mannitol have shown conflicting results. OBJECTIVE: To investigate changes in kidney function in head and neck cancer patients treated with cisplatin with and without additional mannitol infusion. METHODS: A single center, retrospective cohort study of patients with squamous cell carcinoma of the head and neck receiving radiotherapy with cisplatin. Patient data were collected from November 2013 to December 2014. RESULTS: After exclusion, a total of 78 patients were considered evaluable. They were equally distributed between a mannitol and a non-mannitol group and anthropomorphometrically similar. 51Cr-EDTA clearance declined in the mannitol group from 99.7 (19.9) to 96.4 (20.8) mL/min and in the non-mannitol group from 102.2 (17.8) to 92.3 (23.1) mL/min. CONCLUSIONS: There was a significantly smaller decrease in 51Cr-EDTA clearance in the mannitol group indicating a nephroprotective effect of mannitol.