Cardiopulmonary Exercise Testing Versus Frailty, Measured by the Clinical Frailty Score, in Predicting Morbidity in Patients Undergoing Major Abdominal Cancer Surgery.

BACKGROUND: The primary outcome of this study is to investigate the association between the cardiopulmonary exercise testing (CPET) variables: anaerobic threshold (AT), peak oxygen uptake (VO2 peak), peak work rate (WR), ventilatory equivalence of CO2 (VE/VCO2) at the anaerobic threshold (AT) with frailty, measured by the clinical frailty scale (CFS) in patients planned to undergo major abdominal cancer surgery. The secondary outcome is to compare the CPET variables (VO2 peak, peak WR, VE/VCO2 at AT) with frailty measured by the CFS in predicting postoperative surgical morbidity in patients following major abdominal cancer surgery. METHODS: This study was a single-centre prospective cohort analysis of consecutive adult patients undergoing CPET and CFS scoring as part of their pre-operative work-up for major abdominal cancer surgery. RESULTS: A total of n = 317 patients underwent CPET and CFS assessment ahead of planned abdominal oncological surgery. Negative correlations were observed between the CPET variables: AT - 0.42 p < 0.01; VO2 peak - 0.53 p < 0.01; peak WR - 0.54 p < 0.01 with CFS scores and a positive correlation between CFS scores and VE/VCO2 0.29 p < 0.01. Only CFS remained statistically significant in a multivariate model OR 2.11 (1.42-3.15) 95% CI associated with Clavien-Dindo (CD) ≥ 1 defined morbidity including the significant univariate variables (VO2 peak, peak WR and CFS scores). No variables were associated with CD ≥ 3 morbidity. CONCLUSIONS: In patients scheduled to have major abdominal cancer surgery there was a weak association between poor performance on CPET and increasing frailty measured by the CFS. The CFS score unlike CPET was associated with all post-operative morbidity, but not major complications alone, in these patients. This suggests that CFS may be used as a less expensive alternative to CPET for predicting any postoperative morbidity in major abdominal cancer surgery.

Anterior abdominal wall parasitic leiomyoma: case report.

The leiomyomas are a common gynecologic entity that may present unusual growth patterns or unusual locations. Its atypical presentations creates a diagnostic challenge. This is a case report of a parasitic leiomyoma located in the anterior abdominal wall in a 53 years old woman with pelvic compressive and urinary symptoms, with no history of any gynecological surgery. This case illustrates the diagnostic difficulties and describes the complementary images used in the preoperative evaluation.

Temporary Axillorenal Bypass in Complex Aorto-Renal Surgery.

BACKGROUND: Prolonged renal ischemia during vascular surgery carries high morbidity and mortality. We report an alternative technique for maintaining renal circulation during suprarenal aortic or renal artery clamping. METHODS: Between October 2007 and May 2012, 16 patients undergoing aorto-renal surgery (13 men, 3 women) were operated using temporary axillorenal bypass. Operations were performed for supra- and juxtarenal aortic aneurysms (11), occlusive aortic disease (2), renal artery stenoses (2), and abdominal myofibroblastic tumor (1). In elective cases, axillorenal bypass was planned, when prolonged renal ischemia was expected based on preoperative information. Preoperative risk factors (renal dysfunction, hypertension, coronary disease, diabetes, smoking) and intraoperative variables (operating time, blood loss, renal ischemia time) were assessed and compared with postoperative kidney function (serum creatinine, urine output, dialysis) and in-hospital or 30-day-mortality. Even though renal blood flow was restored between clampings, the total cumulative ischemia time was used in analysis. Acute renal failure postoperatively was based on RIFLE criteria. RESULTS: Preoperatively, 44% (7) of the patients had normal renal function (S-crea ≤ 100 mmol/L). Renal function was moderately present in 50% (8) (S-crea 100-200 mmol/L) and severely in 6% (1) (S-crea ≥ 200 mmol/L). Median operation time was 393 min (251-535 min) and median renal ischemia time was 24.5 min (range 8-50 min). Transient acute renal dysfunction occurred in 6 (38%) patients, and 4 of them had renal insufficiency preoperatively. Transient renal replacement therapy was needed in 1 (6%) patient only. In 1-month control, postoperative renal function had returned to its baseline level or improved and in-hospital or 30-day mortality was zero. CONCLUSIONS: Temporary axillorenal bypass is a considerable option to minimize renal ischemia time during high-risk vascular surgery.

Erythrocyte and Biochemical Abnormalities as Diagnostic Markers in Dogs With Hemangiosarcoma Related Hemoabdomen.

OBJECTIVE: To investigate: 1) acanthocytosis and presence of acanthocytes in peritoneal fluid as a diagnostic marker for hemangiosarcoma (HSA) in dogs with non-traumatic hemoabdomen; and 2) the association between other erythrocyte, biochemical, and hematologic abnormalities as a mean of differentiating HSA from other disease. STUDY DESIGN: Prospective double-blinded cohort study. ANIMALS: Dogs (n = 40) with non-traumatic hemoabdomen. METHODS: Dogs diagnosed with hemoabdomen (January 2012 to May 2013) had cytologic evaluation of abdominal effusion and peripheral blood smears. Peripheral blood CBC, PT, and aPTT, as well as blood and effusion acanthocytes, keratocytes, schistocytes, lactate, glucose, PCV, and TP results were compared using the paired t-test or Fisher's exact test. Based on histologic confirmation of HSA, dogs were divided into 2 groups (HSA, non-HSA) and variables compared. RESULTS: There was no significant difference in erythrocyte morphology in abdominal effusion or peripheral blood between dogs with HSA or non-HSA related hemoabdomen. Platelet concentration and peripheral blood PCV were significantly lower in the HSA group. CONCLUSIONS: A reliable preoperative biochemical or cytologic test to differentiate between HSA and non-HSA related hemoabdomen was not identified.

[General principles of tumour biology in visceral surgery]. / Allgemeine Grundlagen der Tumorbiologie in der Viszeralchirurgie.

Within the last decade, there has been a tremendous progress in understanding the molecular basis of cancer. In particular, the development and the characteristic features of cancer cells are being increasingly understood. The understanding of these molecular characteristics is mandatory for the development of novel, targeted therapeutic strategies and their integration into clinical practice. In addition, tumour genetics play a critically important role for hereditary cancer syndromes, with respect to both diagnostics and clinical decision-making. The aim of this review is to highlight general principles of tumour genetics from a visceral surgeon's point of view, although a comprehensive summary of all aspects would be beyond the scope of this article due to the complexity of the topic.

Combined neurolytic block of celiac and superior hypogastric plexuses for incapacitating upper abdominal cancer pain.

PURPOSE: To evaluate the efficacy of a combined neurolytic block of the celiac and superior hypogastric plexuses for incapacitating upper abdominal cancer pain. METHODS: Fifty-two patients with advanced upper abdominal malignancies and incapacitating pain were equally randomized to receive a combined neurolytic block of the celiac and superior hypogastric plexuses (combined group) or a neurolytic celiac plexus block alone (NCPB group) using a 90% ethanol trans-intervertebral disk approach under CT guidance. Visual analogue scores (VAS), morphine consumption, and quality of life (QoL) were assessed before the procedure and 24 hrs, 1 week, 1 month, and 3 months after the procedure. The complications and side effects were also recorded. RESULTS: The amount of ethanol used was 30 ± 5 ml in the combined group and 21 ± 3 ml in the NCPB group. VAS scores and morphine consumption decreased significantly pre- compared to post-procedure in both groups (p<0.05). QoL significantly improved 24 hrs, 1 week, and 1 month after the procedure compared with each group pre-procedure (p<0.05), but not after 3 months (p>0.05). The combined group had significantly lower VAS and morphine consumption than the NCPB group (p<0.05). QoL scores were significantly higher in the combined group 24 hrs, 1 week, and 1 month post-procedure than the NCPB group (p<0.05), but not after 3 months (p>0.05). CONCLUSION: A combined neurolytic block of the celiac and superior hypogastric plexuses is more effective than neurolytic celiac plexus block alone in pain relief for patients with advanced upper abdominal cancer.

Malignant ascites: pathophysiology and treatment.

Malignant ascites (MA) accompanies a variety of abdominal and extra-abdominal tumors. It is a primary cause of morbidity and raises several treatment challenges. MA has several symptoms, producing a significant reduction in the patient's quality of life: loss of proteins and electrolyte disorders cause diffuse oedema, while the accumulation of abdominal fluid facilitates sepsis. Treatment options include a multitude of different procedures with limited efficacy and some degree of risk. A Pubmed, Medline, Embase, and Cochrane Library review of medical, interventional and surgical treatments of MA has been performed. Medical therapy, primarily paracentesis and diuretics, are first-line treatments in managing MA. Paracentesis is widely adopted but it is associated with significant patient discomfort and several risks. Diuretic therapy is effective at the very beginning of the disease but efficacy declines with tumor progression. Intraperitoneal chemotherapy, targeted therapy, immunotherapy and radioisotopes are promising medical options but their clinical application is not yet completely elucidated, and further investigations and trials are necessary. Peritoneal-venous shunts are rarely used due to high rates of early mortality and complications. Laparoscopy and hyperthermic intraperitoneal chemotherapy (HIPEC) have been proposed as palliative therapy. Literature on the use of laparoscopic HIPEC in MA includes only reports with small numbers of patients, all showing successful control of ascites. To date, none of the different options has been subjected to evidence-based clinical trials and there are no accepted guidelines for the management of MA.

[Surgical treatment of desmoid fibroma and sarcoma of the thoracic and abdominal wall].

The article analyses the 17-year (1993-2009 yy) experience of surgical treatment of desmoid fibroma and sarcoma of the thoracic and abdominal wall. 46 operations were analyzed. The radical excision according to the principles of surgical oncology remains the mainstay in the treatment of such patients. The combined technique with the use of polymeric implantates allows to cover large wall defects, thus extending the operability borders and being one of the main factors of the better treatment prognosis.

Preoperative insulin secretion ability and pancreatic parenchymal thickness as useful parameters for predicting postoperative insulin secretion in patients undergoing pancreaticoduodenectomy.

Periampullary malignant neoplasms have been increasing in Japan, mainly in response to an increase in the incidences of pancreatic cancer, and glucose intolerance due to deterioration of insulin secretion is an important problem. We investigated preoperative parameters to predict postoperative insulin secretion and the need for insulin therapy in patients undergoing pancreaticoduodenectomy (PD). Thirty-six patients with malignant neoplasms of periampullary lesions were enrolled. Preoperative pancreatic parenchymal thickness was evaluated by computed tomography. Insulin secretion and glucose tolerance were evaluated by a 75-g oral glucose tolerance test and an intravenous glucagon loading test. The relationships between postoperative insulin secretion and preoperative parameters and the cut-off values for predicting the need for postoperative insulin therapy for glycemic control were investigated. Pancreatic parenchymal thickness and other preoperative parameters, including the increment of serum C-peptide (Δ C-peptide), fasting plasma C-peptide (F-CPR), insulinogenic index (I.I.) and fasting plasma glucose (FPG), were significantly associated with postoperative insulin secretion. Multiple regression analyses revealed that preoperative Δ C-peptide or F-CPR was the most significant determinant of postoperative insulin secretion, followed by pancreatic parenchymal thickness. In the receiver operating characteristic curve, the best preoperative cut-off values for predicting the need for postoperative insulin therapy were a Δ C-peptide of 0.65 ng/mL, a F-CPR of 0.85 ng/mL and a pancreatic parenchymal thickness of 6.0 mm. Both preoperative insulin secretion and pancreatic parenchymal thickness effectively predict postoperative insulin secretion and identify subjects who need postoperative insulin therapy for glycemic control.

A comparison of the respiratory signals acquired by different respiratory monitoring systems used in respiratory gated radiotherapy.

PURPOSE: Respiratory monitoring systems are used to detect the respiratory phase of patients during the planning and administration of respiratory gated radiotherapy by using four-dimensional computed tomography (4DCT) or 4D positron-emission tomography/CT (4DPET/CT) and the linear accelerator (linac), respectively. Generally, identical respiratory monitoring systems are used for 4DCT, 4DPET/CT, and linac. However, different systems are sometimes used in combination because the accessibility of the respiratory monitoring systems may differ by manufacturer. The combined use of different respiratory monitoring systems in phase-based gating is of concern because the differences in the timing of tags (end-respiration signals algorithmically determined by the respiratory monitoring system), defined by the two systems, may result in phase differences, The purpose of this study is to estimate this difference and evaluate its effect on 4DCT data. METHODS: Ten patients (seven men and three women) with a median age of 75 yr (range: 57-84 yr) were treated by gated stereotactic body radiation therapy between April and December 2009. Two types of respiratory monitoring systems--RPM (Varian Medical Systems) and AZ-733V (Anzai MEDICAL)--were placed on the abdominal surface of the patients, and the respiratory signals were acquired by both systems. The relationship between the amplitude peak and the tag obtained by each respiratory system was analyzed for each patient. Further, the 4DCT images were reconstructed by using the signals obtained from both the RPM and the AZ-733V systems, and the tumor volumes and the tumor centroid positions in the craniocaudal plane were analyzed for each patient. RESULTS: The correlation factor between the respiratory signals from the RPM system and AZ-733V system was 0.990 (range: 0.940-0.994). The amplitude peak of the RPM system corresponded well with that of the AZ-733V system. The median +/- standard deviation of the phase difference for all the patients ranged from -4.3 +/- 7.1% to 3.5 +/- 2.2%. In the case of some patients, differences were noted between the two systems in the estimation of the tumor centroid position and tumor shape. CONCLUSIONS: The estimation of the position of the tumor centroid and tumor shape may vary with the use of different respiratory monitoring systems. This implies that it is preferable to use the same respiratory monitoring system with 4DCT, 4DPET-CT, and linac.

A pilot study evaluating predictors of postoperative outcomes after major abdominal surgery: Physiological capacity compared with the ASA physical status classification system.

BACKGROUND: This pilot study compared the risk predictive value of preoperative physiological capacity (PC: defined by gas exchange measured during cardiopulmonary exercise testing) with the ASA physical status classification in the same patients (n=32) undergoing major abdominal cancer surgery. METHODS: Uni- and multivariate logistic regression models were fitted to measurements of PC and ASA rank data determining their predictive value for postoperative morbidity. Receiver operating characteristic (ROC) curves were used to discriminate between the predictive abilities, exploring trade-offs between sensitivity and specificity. RESULTS: Individual statistically significant predictors of postoperative morbidity included the ASA rank [P=0.038, area under the curve (AUC)=0.688, sensitivity=0.630, specificity=0.750] and three newly identified measures of PC: PAT (% predicted anaerobic threshold achieved, <75% vs > or =75%), DeltaHR1 (heart rate response from rest to the anaerobic threshold), and HR3 (heart rate at the anaerobic threshold). A two-variable model of PC measurements (DeltaHR1+PAT) was also shown to be statistically significant in the prediction of postoperative morbidity (P=0.023, AUC=0.826, sensitivity=0.813, specificity=0.688). CONCLUSIONS: Three newly identified PC measures and the ASA rank were significantly associated with postoperative morbidity; none showed a statistically greater association compared with the others. PC appeared to improve predictive sensitivity. The potential for new unidentified measures of PC to predict postoperative outcomes remains unexplored.

Giant, dopamine secreting thoracoabdominal neuroblastoma in a 2-year-old: rapid preoperative blockade with labetalol.

Neuroblastomas secreting large amounts of catecholamines may require preoperative antihypertensive treatment to avoid intraoperative hypertensive crises as do pheochromocytomas. This is typically achieved with alpha-adrenergic followed if necessary by beta-adrenergic receptor blockade. Because of its predominant beta-blockade, labetalol as a combined alpha-adrenergic and beta-adrenergic receptor antagonist is relatively contraindicated as sole and first agent in pheochromocytomas releasing epinephrine and norepinephrine. We report successful monotherapy with labetalol over 24 hours in a 2-year-old child with a giant thoracoabdominal neuroblastoma and predominant dopamine secretion.

Deep learning-based image reconstruction and motion estimation from undersampled radial k-space for real-time MRI-guided radiotherapy.

To enable magnetic resonance imaging (MRI)-guided radiotherapy with real-time adaptation, motion must be quickly estimated with low latency. The motion estimate is used to adapt the radiation beam to the current anatomy, yielding a more conformal dose distribution. As the MR acquisition is the largest component of latency, deep learning (DL) may reduce the total latency by enabling much higher undersampling factors compared to conventional reconstruction and motion estimation methods. The benefit of DL on image reconstruction and motion estimation was investigated for obtaining accurate deformation vector fields (DVFs) with high temporal resolution and minimal latency. 2D cine MRI acquired at 1.5 T from 135 abdominal cancer patients were retrospectively included in this study. Undersampled radial golden angle acquisitions were retrospectively simulated. DVFs were computed using different combinations of conventional- and DL-based methods for image reconstruction and motion estimation, allowing a comparison of four approaches to achieve real-time motion estimation. The four approaches were evaluated based on the end-point-error and root-mean-square error compared to a ground-truth optical flow estimate on fully-sampled images, the structural similarity (SSIM) after registration and time necessary to acquire k-space, reconstruct an image and estimate motion. The lowest DVF error and highest SSIM were obtained using conventional methods up to [Formula: see text]. For undersampling factors [Formula: see text], the lowest DVF error and highest SSIM were obtained using conventional image reconstruction and DL-based motion estimation. We have found that, with this combination, accurate DVFs can be obtained up to [Formula: see text] with an average root-mean-square error up to 1 millimeter and an SSIM greater than 0.8 after registration, taking 60 milliseconds. High-quality 2D DVFs from highly undersampled k-space can be obtained with a high temporal resolution with conventional image reconstruction and a deep learning-based motion estimation approach for real-time adaptive MRI-guided radiotherapy.

Accuracy in the localization of thoracic and abdominal tumors using respiratory displacement, velocity, and phase.

UNLABELLED: Current four dimensional (4D) computed tomography (CT) reconstruction techniques are retrospectively created based on either the phase or displacement of the respiratory signal. Both techniques have known limitations which cause clinically significant motion artifacts in 4D CT images. These artifacts, which appear as undefined or irregular boundaries in the 4D CT images, cause systematic errors in patient contouring and dose calculations. The aim of this work was to evaluate the reproducibility of tumor position as a function of displacement, phase, and velocity of the respiratory signal, respectively, in order to determine the optimum parameter or combination of parameters to use in order to minimize artifacts in 4D CT images or to accurately deliver radiation to relevant structures during treatment. METHOD AND MATERIALS: Estimated tumor centroid position and respiratory signal data were acquired with the Cyberknife Synchrony system for 26 thoracic radiotherapy patients (52 fractions). A reference respiratory cycle was calculated for each patient. Displacement, phase, and velocity of ten data points were calculated from this reference respiratory cycle, where each point represents an image bin. The corresponding tumor position was then sorted into these image bins if the phase, displacement, simultaneous displacement and phase, or simultaneous displacement and velocity of the respiratory signal were within tolerances of 0.5 mm for displacement and 0.5 mm/s for velocity, respectively, from the corresponding data of the reference cycle for each image bin. RESULTS: The mean of the standard deviations of tumor positions over all bins and all fractions for the superior-inferior direction were 2.13 +/- 1.01 mm for phase sorting, 1.20 +/- 0.76 mm for displacement sorting, 1.20 +/- 0.71 mm for simultaneous displacement and phase sorting, and 1.10 +/- 0.71 mm for simultaneous displacement and velocity sorting, with maximum deviations of 43.0, 16.1, 15.5, and 14.1 mm for each scenario, respectively. The same trend was observed for the anterior-posterior and left-right directions. A linear dependence was observed between the mean of the standard deviations of tumor positions over all fractions as a function of the velocity of the respiratory signal at each bin for all the sorting scenarios. A substantially larger gradient for the phase sorting scenario, compared to the other scenarios, suggests that tumor localization will become increasingly less accurate as the velocity of the tumor increases during a breathing cycle, e.g., if the amplitude of motion increases while the period of the respiratory cycle stays constant or during mid inhale or exhale phases of the respiratory cycle. CONCLUSION: This study illustrates that position of a tumor can be determined more accurately if displacement and velocity are used simultaneously as sorting parameters for 4D CT images or during treatment. A real-time displacement and velocity based 4D CT image sorting method may therefore produce fewer and smaller artifacts in 4D CT images than current retrospective sorting methods.

Ganglioneuroblastoma-associated vitamin D deficiency rickets.

Vitamin D deficiency is the most common cause of rickets mainly in breast-fed dark-skinned, African or Asian children receiving inadequate sunlight exposure. We report a case of a 1.5 year-old Afro-Italian male infant living in South Italy who came to our observation with the typical clinical picture of vitamin D deficiency rickets. The child was exclusively breast-fed for 8 months without vitamin D supplements. Owing to the rarity of vitamin D deficiency rickets in the South of Italy he underwent several investigations, which demonstrated the association with an abdominal ganglioneuroblastoma. To our knowledge, ganglioneuroblastoma has never been reported in association with vitamin D deficiency rickets. Although the association between these 2 rare conditions may be coincidental, the protective action of vitamin D against cancer suggests that vitamin D deficiency might have contributed to the development of ganglioneuroblastoma in our patient.

The effect of duration of surgery on fluid balance during abdominal surgery: a mathematical model.

BACKGROUND: There is controversy regarding which fluid management regimen provides the best postoperative outcome. Interstitial fluid accumulation may adversely affect postoperative outcome, but the effect of surgical duration on fluid balance is unknown. In this study, we used a mathematical model to describe fluid distribution. METHODS: Previously published data from bioimpedance analysis in patients undergoing abdominal surgery were used to calculate changes to interstitial volume (DeltaV(IT), percent change relative to baseline) in uninjured and injured tissues. Ratios of DeltaV(IT) in uninjured and injured tissues at the end of surgery to total fluid volume infused during surgery (V(INF), mL/kg) were compared between surgeries of duration <3 h (n = 5) and > or = 3 h (n = 25). Critical values for change in plasma volume (DeltaV(PL), percent change relative to baseline) and DeltaV(IT), which give rise to adverse outcome, were calculated from previously published data on the physiological effects of IV fluid administration in healthy volunteers. Finally, simulated abdominal surgery in a 70 kg man for 1-8 h was used to determine the effect of crystalloid infusion rate between 2 and 30 mL x kg(-1) x h(-1) on DeltaV(PL) and DeltaV(IT). Fluid infusion rates that maintained DeltaV(PL) and DeltaV(IT) in uninjured tissue within critical values were then computationally determined as a function of duration of surgery. RESULTS: Bioimpedance data showed that the differences in DeltaV(IT)/V(INF) ratios between uninjured and injured tissues were significant only for surgical duration > or = 3 h (0.30 +/- 0.17% x kg/mL vs 1.55 +/- 0.73% x kg/mL, P < 0.0001). Differences of DeltaV(IT)/V(INF) ratios between surgical durations <3 and > or = 3 h were found only for injured tissue (0.45 +/- 0.35% x kg/mL vs 1.55 +/- 0.73% x kg/mL, P = 0.003). The range of fluid infusion rates required to maintain DeltaV(PL) and DeltaV(IT) within the critical values (>-15% and <20%, respectively) was wide for short-duration surgery (2-18.5 mL x kg(-1) x h(-1) for a 2 h-surgery), whereas it was narrow for long-duration surgery (5-8 mL x kg(-1) x h(-1) for a 6 h-surgery). CONCLUSIONS: Based on our model, it should be possible to increase the fluid infusion rate without significant interstitial edema for abdominal surgery of <3 h duration. However, our model predicts that restrictive fluid management should be used in abdominal surgery of >6 h duration to avoid excessive interstitial edema.

Oral ketamine for pain relief in a child with abdominal malignancy.

Oral ketamine has been found to be effective during invasive procedures in children with malignancy. To the best of our knowledge, analgesic effects of oral ketamine have not been reported in pediatric cancer pain management. We described a patient with end-stage cancer pain that was resistant to opioids and was relieved by oral ketamine.

[Choice of components and a method of anesthesia in geriatric cancer patients with high cardiovascular risk].

Investigations were made at surgical treatment stages in 102 cancer patients (mean age 72 +/- 5.8 years) at high cardiovascular risk, who received continuous therapy that reduced heart rate and blood pressure, in order to compensate for the course of coronary heart disease and arterial hypertension. The time course of changes in the major circulatory and metabolic parameters was analyzed in patients during operations on the abdomen and small pelvis while using three different multimodal anesthetic techniques (general intravenous anesthesia-based diazepam, propofol, fentanyl, ketamine; sevofluorane-based inhalational; combined epidural and intravenous one). The advantages and limitations of the above methods were shown in patients on cardio- and vasotropic therapies. Correcting modes (transesophageal atrial pacing, morning-dose drug withdrawal) for its possible related bradycardiac and hypotensive disorders, which reduce a risk of perioperative cardiovascular complications, are set forth.

Experience with an abdominal compression band for radiotherapy of upper abdominal tumours.

INTRODUCTION: Radiotherapy outcomes are influenced by treatment delivery geometric accuracy and organ-at-risk dose. The location of abdominal structures such as the liver, kidneys and tumour volumes can be strongly influenced by respiratory motion. This increases geometric uncertainty and dose to organs-at-risk. One common method of minimising respiratory motion is abdominal compression (AC). METHODS: Fifteen patients being treated for radiotherapy to upper abdominal tumours were analysed. Each patient underwent 2 four-dimensional computerised tomography (4D-CT) scans, one with and one without AC with a pneumatic compression belt. Liver and kidney positions were measured on the 4DCT scans at the peak inspiratory and expiratory respiratory phases. The patient received radiation therapy treatment planned on the CT data set with the technique (compression or no compression) that provided the least respiratory motion. RESULTS: There was no statistically significant motion difference over the sample population with AC for the kidneys or liver. Of the 14 evaluable patients, 4, 6 and 6 saw reduction in superior-inferior motion for left kidney, right kidney and liver respectively. The remainder either had negligible (<2 mm) or increase in motion with AC. For anterior-posterior motion, 2, 2 and 1 saw a reduction for left-kidney, right-kidney and liver respectively. CONCLUSION: AC through the use of a pneumatic compression belt was found to result in inconsistent reduction in kidney and liver respiratory motion. It is recommended that the effect of AC is evaluated on a per-patient basis.