A proposed "Radiological Evaluation Score for Bone Tumors" (REST): An objective system for assessment of a radiograph in patients with suspected bone tumor.

BACKGROUND: Although radiographs have been widely used in the evaluation of patients with suspected bone tumors, the lack of an objective radiological assessment method leads to a challenge in reaching correct diagnosis. The study aimed to propose a Radiological Evaluation Score for Bone Tumors (REST) which includes eight radiological factors [characteristics, content, cortical breach, distinctiveness, distribution, periosteal reaction, fracture, and soft tissue swelling] to form a single score along with its validation by multidisciplinary observers. METHODS: We reviewed the radiographs of 100 patients with a primary bone tumor which were selected at random from the database between January 2017 and January 2019 of a tertiary cancer center. Four reviewers (two orthopedic oncologists and two surgical oncologists) independently assessed the radiographs, based on the reporting system of REST. We constituted two groups according to the probable diagnosis of bone tumor (suspected benign tumor and suspected malignant tumor). RESULTS: The mean score in the suspected benign tumor group was 1.1 (range 0-3, 95% CI 0.8-1.3) and in malignant tumor group was 6.1 (range 2-8, 95% CI 5.8-6.4). A receiver operator characteristic (ROC) curve for REST was with a cutoff of 3.5, with the most diagnostic value area under curve (AUC) of 0.99. The sensitivity was 98% and specificity was 100% with a positive predictive value of 100% and a negative predictive value of 98%. The inter-observer correlation coefficient was 0.985 (p value < 0.05), and Fleiss kappa value for the prediction of the benign or malignant lesion was 0.97 (p value < 0.05). The characteristics and content of tumor, cortical erosion, distinctiveness, distribution, periosteal reaction, and soft tissue mass had a significant correlation with the aggressiveness of bone lesion p value < 0.05. CONCLUSIONS: The Radiological Evaluation Score for Bone Tumors (REST) is a structured reporting and objective method for the assessment of radiographs in patients with suspected bone tumors. This method is a reliable and helpful tool for clinicians in their outdoor patient department to differentiate a radiograph of a suspected benign tumor from a malignant bone tumor.

A proposed ''A to Z RAM (Radiograph Assessment Method)'' for triage of patients with a suspected bone tumour.

INTRODUCTION: We propose a ''A to Z RAM (Radiograph Assessment Method)'' for evaluation of Radiograph of patients with a suspected bone tumour. METHODS: In the current study, ten radiological features with letters 'A, B, C, D, E, F and Z' were used and which included the age of the patient, involved part of the bone, characteristics, content, distinctiveness, the exterior of the bone, fracture, and zone of transition. Four independent observers (orthopaedic oncologists and surgical oncologists) evaluated a set of 30 radiographs of bone tumour selected at random from our hospital database based on A to Z RAM. We classified the lesions into two groups according to the traffic signal system; Green (suspected benign lesion) and Red (suspected malignant lesion). RESULTS: There were 18 (60%) benign bone lesions and 12 (40%) malignant lesions in the current study. 91.6% of malignant tumours and 88.8% of the benign tumours were identified correctly by the four observers. The inter-observer variability with Fleiss kappa was 0.884 (95% CI 0.7-1.03 p-value < 0.05), suggestive of agreement not by chance. These radiographs were again reassessed by the four observers after 3 months. The interobserver variability by Fleiss kappa was 1.0 (95% CI 0.8-1.1) suggesting complete agreement amongst the observers. Both orthopaedic oncologists had intra-observer kappa as 1.0 each and both surgical oncologists had 0.795 and 0.930 respectively. CONCLUSION: The proposed A to Z RAM is an easy to use and reproducible method for reviewing radiographs in the out-patient department along with clinical findings for better management of patients with suspected bone lesions. The A to Z RAM can be a medical triage tool and subdivide bone lesions into two subgroups i.e. suspected benign lesion with a suggestion of further investigations with MRI and biopsy and suspected malignant lesion with a suggestion of MRI or early referral to a tertiary cancer center with expertise in orthopaedic oncology. IMPLICATIONS FOR PRACTICE: The A to Z RAM (Radiologic Assessment Method) is a reproducible method for reviewing radiographs in the out-patient department and can be an aid for better management of patients. A to Z RAM is useful as a medical triage system, subdividing patients according to the probable diagnosis into a suspected benign lesion and suspected malignant lesion.

Interspecies acetate transfer influences the extent of anaerobic benzoate degradation by syntrophic consortia.

Benzoate degradation by an anaerobic, syntrophic bacterium, strain SB, in coculture with Desulfovibrio sp. strain G-11 reached a threshold value which depended on the amount of acetate added and ranged from about 2.5 to 29.9 (mu)M. Increasing acetate concentrations also uncompetitively inhibited benzoate degradation. The apparent V(infmax) and apparent K(infm) for benzoate degradation decreased with increasing acetate concentration, but the benzoate degradation capacities (V(infmax)/K(infm)) of cell suspensions remained comparable. The addition of an acetate-using bacterium to cocultures after the threshold was reached resulted in the degradation of benzoate to below the detection limit. Mathematical simulations showed that the benzoate threshold was not predicted by the inhibitory effect of acetate on benzoate degradation kinetics. With nitrate instead of sulfate as the terminal electron acceptor, no benzoate threshold was observed in the presence of 20 mM acetate even though the kinetics of benzoate degradation were slower with nitrate rather than sulfate as the electron acceptor. When strain SB was grown with Desulfovibrio sp. strain DG2 that had a fourfold-lower V(infmax) for hydrogen use than strain G-11, the V(infmax) for benzoate degradation was 37-fold lower than that of strain SB-G-11 cocultures. The Gibb's free energy for benzoate degradation was less negative in cell suspensions with a threshold than in suspensions without a threshold. These studies showed that the threshold was not a function of the inhibition of benzoate degradation by acetate or the toxicity of the undissociated form of acetate. Rather, a critical or minimal Gibb's free energy may exist where thermodynamic constraints preclude further benzoate degradation.

Evidence for anaerobic syntrophic benzoate degradation threshold and isolation of the syntrophic benzoate degrader.

An anaerobic, motile, gram-negative, rod-shaped, syntrophic, benzoate-degrading bacterium, strain SB, was isolated in pure culture with crotonate as the energy source. Benzoate was degraded only in association with an H2-using bacterium. The kinetics of benzoate degradation by cell suspensions of strain SB in coculture with Desulfovibrio strain G-11 was studied by using progress curve analysis. The coculture degraded benzoate to a threshold concentration of 214 nM to 6.5 microM, with no further benzoate degradation observed even after extended incubation times. The value of the threshold depended on the amount of benzoate added and, consequently, the amount of acetate produced. The addition of sodium acetate, but not that of sodium chloride, affected the threshold value; higher acetate concentrations resulted in higher threshold values for benzoate. When a cell suspension that had reached a threshold benzoate concentration was reamended with benzoate, benzoate was used without a lag. The hydrogen partial pressure was very low and formate was not detected in cell suspensions that had degraded benzoate to a threshold value. The Gibbs free energy change calculations showed that the degradation of benzoate was favorable when the threshold was reached. These studies showed that the threshold for benzoate degradation was not caused by nutritional limitations, the loss of metabolic activity, or inhibition by hydrogen or formate. The data are consistent with a thermodynamic explanation for the existence of a threshold, but a kinetic explanation based on acetate inhibition may also account for the existence of a threshold.