Prognostic value of deep learning-derived body composition in advanced pancreatic cancer-a retrospective multicenter study

BACKGROUND

Despite the prognostic relevance of cachexia in pancreatic cancer, individual body composition has not been routinely integrated into treatment planning. In this multicenter study, we investigated the prognostic value of sarcopenia and myosteatosis automatically extracted from routine computed tomography (CT) scans of patients with advanced pancreatic ductal adenocarcinoma (PDAC).

PATIENTS AND METHODS

We retrospectively analyzed clinical imaging data of 601 patients from three German cancer centers. We applied a deep learning approach to assess sarcopenia by the abdominal muscle-to-bone ratio (MBR) and myosteatosis by the ratio of abdominal inter- and intramuscular fat to muscle volume. In the pooled cohort, univariable and multivariable analyses were carried out to analyze the association between body composition markers and overall survival (OS). We analyzed the relationship between body composition markers and laboratory values during the first year of therapy in a subgroup using linear regression analysis adjusted for age, sex, and American Joint Committee on Cancer (AJCC) stage.

RESULTS

Deep learning-derived MBR [hazard ratio (HR) 0.60, 95% confidence interval (CI) 0.47-0.77, P < 0.005] and myosteatosis (HR 3.73, 95% CI 1.66-8.39, P < 0.005) were significantly associated with OS in univariable analysis. In multivariable analysis, MBR (P = 0.019) and myosteatosis (P = 0.02) were associated with OS independent of age, sex, and AJCC stage. In a subgroup, MBR and myosteatosis were associated with albumin and C-reactive protein levels after initiation of therapy. Additionally, MBR was also associated with hemoglobin and total protein levels.

CONCLUSIONS

Our work demonstrates that deep learning can be applied across cancer centers to automatically assess sarcopenia and myosteatosis from routine CT scans. We highlight the prognostic role of our proposed markers and show a strong relationship with protein levels, inflammation, and anemia. In clinical practice, automated body composition analysis holds the potential to further personalize cancer treatment.

[Soft tissue defects following tumor resection in the limbs and trunk : Plastic reconstructive soft tissue and revision concepts]

BACKGROUND

Tissue defects of the trunk and limbs after oncologic surgery and radiation require plastic reconstructive tissue coverage. Depending on the location and size of the wound as well as the interdisciplinary treatment concept, different reconstructive procedures are performed. These range from skin transplantation to local and pedicle flaps, to perforator flaps and free microsurgical tissue transfer.

METHODS

The modern "reconstructive ladder" can be regarded as an orientation for the sequence of the reconstructive options. Considering the patient's wishes and risk profile, an individual reconstructive concept must be devised. The best functional and simultaneously safest procedure with the smallest secondary defect is to be chosen. Wound preconditioning via vacuum-assisted closure can precede definitive tissue coverage in order to optimize local conditions.

CONCLUSION

Safe tissue coverage can be achieved even in advanced stages of oncologic disease and after extensive surgery by performing wound preconditioning and arteriovenous loop grafting to induce safe de novo recipient vessels for two-stage free tissue transfer. The choice between maximum plastic reconstructive options for a curative approach or limited palliative surgery is to be harmonized and balanced with therapeutic goals and the patient's biologic resources. Preservation and restoration of quality of life and functionality is the plastic surgeon's dictum.

Provocation of coronary spasm by dobutamine stress echocardiography in a patient with angiographically minimal coronary artery disease

Dobutamine stress echocardiography (DSE) has been widely used for the noninvasive diagnosis of obstructive coronary artery disease. The ST-segment elevation during DSE has been reported as an infrequent event, caused by old myocardial infarction and/or critical coronary narrowings. The patient presented here was a 35-year-old man with a recent history of nonexertional chest pain. He had hypercholesterolemia and a history of heavy smoking as risk factors. The patient developed ST-segment elevation with chest pain during 40 mcg/min dobutamine infusion for the stress echocardiographic examination. Subsequent coronary angiograms revealed only mild coronary atherosclerosis. It is speculated that coronary spasm occurred in this patient as a paradoxical response to increased coronary blood flow with dobutamine administration.

Hemodynamic changes pre- and post-pacing with complete heart block and aortic valve stenosis and regurgitation

Conduction disturbances in the setting of calcific aortic valve disease have been well documented in the literature. In this report we describe a case of a patient who presented in complete heart block and dyspnea on exertion. Subsequent non-invasive and invasive studies revealed moderate aortic stenosis and regurgitation with preserved left ventricular function. Hemodynamically important physiological pressure waveform changes occurred before and after pacing the ventricles and are highlighted here.

Importance of a non-dominant right coronary artery occlusion presenting as sudden cardiac death with prolonged right ventricular dysfunction and malignant arrhythmias

We report a case of a patient who presented with sudden cardiac death secondary to a subtotal occlusion of a small non-dominant right coronary system. Catheterization several weeks following the initial episode revealed persistent severe right ventricular dysfunction with moderate hemodynamic compensation. Continued unstable arrhythmogenic potential at this point led to placement of an AICD device. The case highlights the potential hazard and often complacency involved in dealing with benign appearing lesions as this one.

Glycolytic enzymes from human autoptic brain cortex: normal aged and demented cases

The activities of glycolytic enzymes were determined in human autoptic temporal lobes from patients with different forms of dementia. For some enzymes (hexokinase, phosphofructokinase and phosphoglycerate mutase) the effect seen in dementia can be regarded as an intensification of the normal ageing affect. For other enzymes (aldolase, phosphoglucose isomerase, triosephosphate isomerase and lactate dehydrogenase) no changes in enzyme activities corresponding to those found in dementia are observed in the normal ageing process. These effects are most pronounced in the non-vascular Alzheimer cases. With the exception of triosephosphate isomerase and lactate dehydrogenase, enzyme activity is also reduced in bronchopneumonia. The effects of dementia and bronchopneumonia on the activities of glycolytic enzymes in human autoptic brain tissue are often difficult to distinguish.

[The influence of aging, post-mortem delay until isolation of the tissue and duration of agony on some glycolytic enzymes in human autoptic brain tissue (author's transl)]

The influence of aging and pre- and post-mortem conditions on the activities of glycolytic enzymes and of the ATPases was determined in samples of autoptic human cerebral cortex and putamen. These results were compared with results obtained from an aging collective of rats (four groups ranging from 20 to 120 weeks of age). The results revealed an interlinked significant age-related increase in soluble hexokinase (HK) and a significant decrease in phosphofructokinase (PFK) activity in human autoptic tissue, whereas no significant age-dependent differences could be observed in rat brain. Subdivision of the cases according to duration of agony and other pre-mortem conditions revealed reduced variance and therefore statistically more significant PFK age-dependence in cases with a short agony. All other cases are not dependent on age. In addition to the pre- and post-mortem effects, the age-dependence of PFK and soluble HK can be clearly demonstrated in human autoptic brain tissue.

+Gz tolerance in man after 14-day bedrest periods with isometric and isotonic exercise conditioning

The purpose of this study was to determine the effects of isometric or isotonic exercise training on post-bedrest +Gz tolerance. Seven male volunteers, 19-22 years, underwent accelerations of +2.1 Gz (740 s), +3.2 Gz (327 s), and +3.8 Gz (312 s) in a selected, randomized order; the ramp to peak acceleration was 1.8 G/min. The centrifugation runs were terminated by loss of central vision (blackout) to a white light with a luminance of 3.15 times 10-5 log candle/cm-2 (0.092 ft-lambert). The study began with a 14-d ambulatory control period, followed by three 14-d bedrest periods (each separated by a 21-d recovery period) and then a final week of recovery. During the ambulatory periods, the subjects exercised on a bicycle ergometer at 50% of their maximal oxygen uptake (max VO2) for 1 h/d. During two of the three bedrest periods, the subjects performed in the supine position one of two routines, either isometric exercise (21% of max leg extension force for 1 min followed by 1-min rest) or isotonic exercise (68% of max VO2) for 0.5 in the morning and afternoon. During the third bedrest period, no exercise was performed. In general +Gz tolerance was reduced by 24% to 35% (p less than or equal to 0.05) after bedrest. Compared with control values, there were significant reductions in average tolerance times after bedrest with no exercise and isotonic exercise at all G levels. With isometric exercise, there was a significant decrease in tolerance at 2.1 Gz but not at 3.2 Gz or 3.8 Gz, even though the latter tolerances were reduced 15.6% and 10.0%, respectively. Both exercise regimens maintained tolerance at levels equal to or above that obtained with no exercise. Compared with control values, average tolerances were lower (p less than or equal to 0.05) after the two recovery periods between the bedrest periods (minus 24% to minus 26% at 3.2 Gz and 3.8 Gz), indicating that 3 weeks of ambulation was not sufficient time for full recovery from the deconditioning induced in this study. A prediction equation was constructed with data from all comparable studies utilizing deconditioned men riding relaxed without protective garments: Tolerance (in seconds) equals minus 334 + (1715/+Gz level). From this equation, the calculated tolerance after bedrest is 13.5 min at 1.5 G, and the point of zero tolerance is 5.1 Gz.