Correlation between whole skeleton dual energy CT calcium-subtracted attenuation and bone marrow infiltration in multiple myeloma.

OBJECTIVES: Objective evaluation of the extent of skeletal marrow involvement in multiple myeloma remains a clinical gap for CT. We aimed to develop a quantitative segmentation pipeline for dual energy CT and to assess whether quantified whole skeleton calcium-subtracted attenuation values correlate with biopsy-derived bone marrow infiltration in multiple myeloma. METHODS: Consecutive prospective patients with suspected/established myeloma underwent dual source CT from the skull vertex to proximal tibia. Whole skeleton segmentation was performed for 120 kVp-equivalent images as follows: following Hounsfield unit (HU) thresholding, a Chan-Vese morphological operation was implemented to generate a whole skeleton segmentation mask. This mask was then applied to corresponding whole skeleton material decomposition calcium-subtracted maps, generating whole skeleton HU values. Associations with biopsy-derived bone marrow plasma cell infiltration percentage were assessed with Spearman's rank correlation; significance was at 5%. RESULTS: 21 patients (12 females; median (IQR) 67 (61, 73) years) were included; 16 patients had osteolytic bone lesions; 15 patients underwent bone marrow biopsy. Segmentation and quantification were feasible in all patients. Median (IQR) of the average skeletal calcium-subtracted attenuation was -59.9 HU (-66.3, -51.8HU). There was a positive correlation with bone marrow plasma cell infiltration percentage (Spearman's rho: + 0.79, p < 0.001). CONCLUSION: Whole skeleton calcium-subtracted attenuation is associated with the degree of bone marrow infiltration by plasma cells, providing an objective measure of marrow involvement with the potential to allow earlier detection of disease.

The biphasic transmittance waveform: an early marker of sepsis in patients with neutropenia.

Transmittance waveform (TW) analysis has been proposed as a method of both prediction and monitoring of non-overt and overt disseminated intravascular coagulation. This study assessed the use of the rapidTW of the activated partial thromboplastin time in the detection of sepsis in 49 consecutive neutropenic haemato-oncology patients. A slope 1 cut-off value of -0.050 was found to be optimum giving 85% sensitivity with 92% specificity and positive and negative predictive values of 62% and 98%, respectively. Furthermore a worsening slope 1 value at 24 hours was indicative of a 60% increase in mortality risk. Haemato-oncology patients have a significantly increased risk of developing sepsis during intensive chemotherapy, exacerbated by the resultant neutopenia. This sepsis may progress extremely rapidly and is associated with a high mortality. Early diagnosis is therefore critical and is currently made on a predominantly clinical basis with supporting microbiological evidence 2-3 days later. This study showed that TW offers an early marker, predictive of sepsis in neutropenic patients. It correlates with subsequent microbiological results and may identify patients at greater risk of clinical deterioration who may require more intensive early therapy or observation. It may also provide a useful marker to monitor the effects of treatment.