Sympathetic nerve blocks for persistent pain in adults with inoperable abdominopelvic cancer.

BACKGROUND: Persistent visceral pain is an unpleasant sensation coming from one or more organs within the body. Visceral pain is a common symptom in those with advanced cancer. Interventional procedures, such as neurolytic sympathetic nerve blocks, have been suggested as additional treatments that may play a part in optimising pain management for individuals with this condition. OBJECTIVES: To evaluate the benefits and harms of neurolytic sympathetic nerve blocks for persistent visceral pain in adults with inoperable abdominopelvic cancer compared to standard care or placebo and comparing single blocks to combination blocks. SEARCH METHODS: We searched the following databases without language restrictions on 19 October 2022 and ran a top-up search on 31 October 2023: CENTRAL; MEDLINE via Ovid; Embase via Ovid; LILACS. We searched trial registers without language restrictions on 2 November 2022: ClinicalTrials.gov; WHO International Clinical Trials Registry Platform (ICTRP). We searched grey literature, checked reference lists of reviews and retrieved articles for additional studies, and performed citation searches on key articles. We also contacted experts in the field for unpublished and ongoing trials. Our trial protocol was preregistered in the Cochrane Database of Systematic Reviews on 21 October 2022. SELECTION CRITERIA: We searched for randomised controlled trials (RCTs) comparing any sympathetic nerve block targeting sites commonly used to treat abdominal pelvic pain from inoperable malignancies in adults to standard care or placebo. DATA COLLECTION AND ANALYSIS: We independently selected trials based on predefined inclusion criteria, resolving any differences via adjudication with a third review author. We used a random-effects model as some heterogeneity was expected between the studies due to differences in the interventions being assessed and malignancy types included in the study population. We chose three primary outcomes and four secondary outcomes of interest. We sought consumer input to refine our review outcomes and assessed extracted data using Cochrane's risk of bias 2 tool (RoB 2). We assessed the certainty of evidence using the GRADE system. MAIN RESULTS: We included 17 studies with 1025 participants in this review. Fifteen studies with a total of 951 participants contributed to the quantitative analysis. Single block versus standard care Primary outcomes No included studies reported our primary outcome, 'Proportion of participants reporting no worse than mild pain after treatment at 14 days'. The evidence is very uncertain about the effect of sympathetic nerve blocks on reducing pain to no worse than mild pain at 14 days when compared to standard care due to insufficient data (very low-certainty evidence). Sympathetic nerve blocks may provide small to 'little to no' improvement in quality of life (QOL) scores at 14 days after treatment when compared to standard care, but the evidence is very uncertain (standardised mean difference (SMD) -0.73, 95% confidence interval (CI) -1.70 to 0.25; I² = 87%; 4 studies, 150 participants; very low-certainty evidence). The evidence is very uncertain about the risk of serious adverse events as defined in our review as only one study contributed data to this outcome. Sympathetic nerve blocks may have an 'increased risk' to 'no additional risk' of harm compared with standard care (very low-certainty evidence). Secondary outcomes Sympathetic nerve blocks showed a small to 'little to no' effect on participant-reported pain scores at 14 days using a 0 to 10 visual analogue scale (VAS) for pain compared with standard care, but the evidence is very uncertain (mean difference (MD) -0.44, 95% CI -0.98 to 0.11; I² = 56%; 5 studies, 214 participants; very low-certainty evidence). There may be a 'moderate to large' to 'little to no' reduction in daily consumption of opioids postprocedure at 14 days with sympathetic nerve blocks compared with standard care, but the evidence is very uncertain (change in daily consumption of opioids at 14 days as oral milligrams morphine equivalent (MME): MD -41.63 mg, 95% CI -78.54 mg to -4.72 mg; I² = 90%; 4 studies, 130 participants; very low-certainty evidence). The evidence is very uncertain about the effect of sympathetic nerve blocks on participant satisfaction with procedure at 0 to 7 days and time to need for retreatment or treatment effect failure (or both) due to insufficient data. Combination block versus single block Primary outcomes There is no evidence about the effect of combination sympathetic nerve blocks compared with single sympathetic nerve blocks on the proportion of participants reporting no worse than mild pain after treatment at 14 days because no studies reported this outcome. There may be a small to 'little to no' effect on QOL score at 14 days after treatment, but the evidence is very uncertain (very low-certainty evidence). The evidence is very uncertain about the risk of serious adverse events with combination sympathetic nerve blocks compared with single sympathetic nerve blocks due to limited reporting in the included studies (very low-certainty evidence). Secondary outcomes The evidence is very uncertain about the effect of combination sympathetic nerve blocks compared with single sympathetic nerve blocks on participant-reported pain score and change in daily consumption of opioids postprocedure, at 14 days. There may be a small to 'little to no' effect, but the evidence is very uncertain (very low-certainty evidence). There is no evidence about the effect on participant satisfaction with procedure at 0 to 7 days and time to need for retreatment or treatment effect failure (or both) due to these outcomes not being measured by the studies. Risk of bias The risk of bias was predominately high for most outcomes in most studies due to significant concerns regarding adequate blinding. Very few studies were deemed as low risk across all domains for any outcome. AUTHORS' CONCLUSIONS: There is limited evidence to support or refute the use of sympathetic nerve blocks for persistent abdominopelvic pain due to inoperable malignancy. We are very uncertain about the effect of combination sympathetic nerve blocks compared with single sympathetic nerve blocks. The certainty of the evidence is very low and these findings should be interpreted with caution.

[Surgery for abdominal neuroblastoma in children]. / Khirurgiya neiroblastomy abdominal'noi lokalizatsii u detei.

This review is devoted to surgical approach for neurogenic tumors in children. The authors discuss epidemiological data, history of surgical approaches, preoperative imaging and risk factors. A special attention is paid to the influence of surgical interventions for various neuroblastomas on overall and event-free survival in pediatric population, as well as the most common surgical complications and modern approaches to their treatment.

Long-term effects of local radiotherapy on growth and vertebral features in children with high-risk neuroblastoma.

BACKGROUND: To evaluate the effects of local radiotherapy (RT) on growth, we evaluated the chronological growth profiles and vertebral features of children with high-risk neuroblastoma. METHODS: Thirty-eight children who received local photon or proton beam therapy to the abdomen or retroperitoneum between January 2014 and September 2019 were included. Simple radiography of the thoracolumbar spine was performed before and every year after RT. The height and vertical length of the irradiated vertebral bodies (VBs) compared with the unirradiated VBs (vertebral body ratio, VBR) were analyzed using the linear mixed model. Shape feature analysis was performed to compare the irradiated and unirradiated vertebrae. RESULTS: The follow-up was a median of 53.5 months (range, 21-81 months) after RT. A decline in height z-scores was mainly found in the early phase after treatment. In the linear mixed model with height, the initial height (fixed, p < 0.001), sex (time interaction, p = 0.008), endocrine dysfunction (time interaction, 0.019), and age at diagnosis (fixed and time interaction, both p = 0.002) were significant. Unlike the trend in height, the change in VBR (ΔVBR) decreased gradually (p < 0.001). The ΔVBR in the group that received more than 30 Gy decreased more than in the group that received smaller doses. In the shape feature analysis, the irradiated VBs changed to a more irregular surface that were neither round nor rectangular. CONCLUSION: The irradiated VBs in children were gradually restricted compared to the unirradiated VBs in long-term follow-up, and higher RT doses were significantly affected. Radiation-induced irregular features of VBs were observed.

Risk factors, impact and treatment of postoperative lymphatic leakage in children with abdominal neuroblastoma operated on by laparotomy.

BACKGROUND: Lymphatic leakage is one of the postoperative complications of neuroblastoma. The purpose of this study is to summarize the clinical characteristics and risk factors of lymphatic leakage and try to find effective prevention and treatment measures. METHODS: A retrospective study included 186 children with abdominal neuroblastoma, including 32 children of lymphatic leakage and 154 children of non-lymphatic leakage. The clinical information, surgical data, postoperative abdominal drainage, treatment of lymphatic leakage and prognosis of the two groups were collected and analyzed. RESULTS: The incidence of lymphatic leakage in this cohort was 14% (32 children). Through univariate analysis of lymphatic leakage group and non-lymphatic leakage group, we found that lymphatic leakage increased the complications, prolonged the time of abdominal drainage and hospitalization, and delayed postoperative chemotherapy (p < 0.05). In this cohort, the median follow-up time was 46 (95% CI: 44-48) months. The follow-up data of 7 children were partially missing. 147 children survived, of which 23 had tumor recurrence (5 children recurred in the surgical area). 37 children died, of which 32 had tumor recurrence (9 children recurred in the operation area). In univariate analysis, there was no statistical difference in overall survival (p = 0.21) and event-free survival (p = 0.057) between lymphatic leakage group and non-lymphatic leakage group, while 3-year cumulative incidence of local progression was higher in lymphatic leakage group (p = 0.015). However, through multivariate analysis, we found that lymphatic leakage did not affect event-free survival, overall survival and cumulative incidence of local progression in children with neuroblastoma. Resection of 5 or more lymphatic regions was an independent risk factor for lymphatic leakage after neuroblastoma surgery. All 32 children with lymphatic leakage were cured by conservative treatment without surgery. Of these, 75% (24/32) children were cured by fat-free diet or observation, 25% (8/32) children were cured by total parenteral nutrition. The median drain output at diagnosis in total parenteral nutrition group was higher than that in non-total parenteral nutrition group (p < 0.001). The cut-off value was 17.2 ml/kg/day. CONCLUSIONS: Lymphatic leakage does not affect the prognosis of children with neuroblastoma, but long-term drain output caused by lymphatic leakage will still adversely affect postoperative complications and follow-up treatment, which requires attention and active treatment measures. More attention should be paid to the children with 5 or more lymphatic regions resection, and the injured lymphatic vessels should be actively found and ligated after tumor resection to reduce the postoperative lymphatic leakage. Early application of total parenteral nutrition is recommended for those who have drain output at diagnosis of greater than 17.2 ml/kg/day. LEVEL OF EVIDENCE: Level III, Treatment study (Retrospective comparative study).

Staging and Restaging Pediatric Abdominal and Pelvic Tumors: A Practical Guide.

The most common abdominal malignancies diagnosed in the pediatric population include neuroblastoma, Wilms tumor, hepatoblastoma, lymphoma, germ cell tumor, and rhabdomyosarcoma. There are distinctive imaging findings and patterns of spread for each of these tumors that radiologists must know for diagnosis and staging and for monitoring the patient's response to treatment. The multidisciplinary treatment group that includes oncologists, surgeons, and radiation oncologists relies heavily on imaging evaluation to identify the best treatment course and prognostication of imaging findings, such as the image-defined risk factors for neuroblastomas, the PRETreatment EXtent of Disease staging system for hepatoblastoma, and the Ann Arbor staging system for lymphomas. It is imperative for radiologists to be able to correctly indicate the best imaging methods for diagnosis, staging, and restaging of each of these most prevalent tumors to avoid inconclusive or unnecessary examinations. The authors review in a practical manner the most updated key points in diagnosing and staging disease and assessing response to treatment of the most common pediatric abdominal tumors. ©RSNA, 2024 Supplemental material is available for this article.

PSMA-Avid Desmoid Tumor of the Abdominal Wall on 18 F-Piflufolastat PET/CT.

ABSTRACT: Prostate-specific membrane antigen (PSMA) PET/CT is widely used in the evaluation of suspected metastasis for initial definitive therapy and suspected recurrence of prostate cancer. We outline a case report of a 62-year-old man with history of prostate cancer treated with surgery, salvage radiation, and hormonal therapy presenting with rising PSA levels. There was incidental detection of a PSMA-avid subcutaneous abdominal wall mass on PSMA PET/CT study, which was consistent with desmoid fibromatosis on an ultrasound-guided biopsy.

Innervated vastus lateralis muscle: complementing and completing the anterolateral thigh flap for abdominal wall reconstruction.

Reconstruction of composite abdominal wall defects is challenging. An anterolateral thigh (ALT) flap has established itself in the algorithm for abdominal wall reconstruction. Augmenting innervated vastus lateralis (iVL) muscle to ALT has added advantages. We describe previously unreported advantage of ALT with iVL.A woman in her 30s, suffering from Mullerian adenocarcinoma with metastasis to the right anterior abdominal wall and right inguinal lymph node, was taken for wide local excision and reconstruction. After excision, there was a 15×12 cm defect of the anterior abdominal wall. We reconstructed the defect with prosthetic mesh and pedicled composite ALT and iVL. There was venous congestion in the ALT flap and it could not be salvaged. We debrided the ALT flap and applied split skin graft over iVL. The grafted and donor sites healed well. The patient was able to do moderate strenuous activities. The presence of iVL allowed us to get away with minor procedure and averted the need for another flap.

Intraoperative radiofrequency ablation for unresectable abdominal paraganglioma: a case report.

For pheochromocytoma and paraganglioma (PPGL), the efficacy of percutaneous ablative therapies in achieving control of metastatic tumors measuring <3 cm had been demonstrated in only few reports, and intraoperative radiofrequency ablation (RFA) of locally invasive primary PPGLs has not been reported. We presented the case of a 31-year-old man who had a 9-cm functioning unresectable PPGL. He was treated with 13 cycles of cytotoxic chemotherapy without objective tumor response, according to the Response Evaluation Criteria in Solid Tumors (RECIST). Subsequently, magnetic resonance imaging revealed a 9.0 × 8.6 × 6.0-cm retroperitoneal mass that extended to the inferior portion of the inferior vena cava, the inferior mesenteric artery, and the infrarenal aorta. Biochemical evaluation demonstrated high level of plasma normetanephrine (20.2 nmol/L, normal range <0.9 nmol/L). Genetic investigation showed the germline pathogenic variant c.1591delC (p. Ser198Alafs*22) in the SDHB gene. I131-metaiodobenzylguanidine scintigraphy was negative and Ga68-dotatate PET-CT scan showed high tumor uptake without distant metastases. On open laparotomy, tumor debulking was not possible. Therefore, intraoperative RFA was performed by a highly experienced team of interventional radiologists. At 12 months after the RFA, the tumor volume decreased from 208 to 45 mL (78%), plasma normetanephrine decreased from 20.2 to 2.6 nmol/L (87%), and the doxazosin dose was reduced from 16 to 8 mg/day. To our best knowledge, this was the first report on intraoperative RFA that markedly reduced the size of a large primary unresectable PPGL, along with clinical and biochemical responses.

Fried Frailty Phenotype Questionnaire scores and postoperative patient-reported outcomes of patients undergoing major abdominal cancer surgery: A secondary analysis.

AIM: This study aimed to evaluate the effects of Fried Frailty Phenotype Questionnaire (FFPQ) scores on patient-reported postoperative outcomes. METHODS: This secondary analysis of a prospective observational study included 230 inpatients aged ≥65 years undergoing elective abdominal cancer surgery. The primary outcome was the Quality of Recovery-15 score on postoperative days 2, 4 and 7. The secondary outcomes included disability-free survival, defined as a 12-item World Health Organization Disability Assessment Schedule 2.0 score of <16% at 3 months. The associations of the FFPQ scores, ranging from 0 (robust) to 5 (frailty), with the primary and secondary outcomes were assessed using multiple analysis. RESULTS: After confirming the linearity of the FFPQ score for the outcomes, multiple regression analysis adjusted for prominent factors showed that the FFPQ score was a significant factor influencing the decrease in the Quality of Recovery-15 score on postoperative day 2 (ß = -2.67, 95% confidence interval -5.20, -0.15), 4 (ß = -3.54, 95% confidence interval -5.77, -1.30) and 7 (ß = -3.70, 95% confidence interval -5.75, -1.65). The adjusted odds ratio of the FFPQ score for disability-free survival postoperatively was 0.66 (95% confidence interval 0.49-0.90). CONCLUSIONS: Patients with higher FFPQ scores before elective major abdominal cancer surgery were likely to have lower postoperative Quality of Recovery-15 scores and poor disability-free survival. Geriatr Gerontol Int 2024; 24: 464-469.

Management of Abdominal Paraganglioma: A Single Center's Experience.

Background and Objectives: Paragangliomas (PGLs) are rare neuroendocrine extra-adrenal tumors that could be secreting mass. The symptoms are the typical triad of paroxysmal headache, hypertension and sweating, but could also be accompanied by symptoms involving multiple organs. Surgery is the gold standard treatment for both PGLs and pheochromocytomas (PHEOs). Material and Methods: We used a computerized endocrine surgery registry to record the demographic and clinical data of 153 patients who underwent surgery for PPGL between 2010 and 2023 at our hospital. Results: Thirteen patients (8.43%) with paragangliomas underwent surgery at our institute. Five patients presented symptomatic syndrome. Preoperative investigations included enhanced abdominal CT (nine patients) and enhanced MRI (seven patients). In cases of suspicious mass, we performed 131I-MIBG scans (two patients) or 68GA-DOTATOC PET-CT scans (11 patients). Laparoscopic approach was used in four cases (30.7%) and abdominal laparotomy in the other nine (69.3%). Biochemical tests were performed on all patients. Conclusions: In this retrospective study, we discuss the multidisciplinary management in our institute of this rare disease, from its challenging diagnosis to the surgical strategy for PGLs. Laparoscopic surgery is the gold standard, but a tailored approach should be adopted for each patient.

Response Evaluation Criteria in Gastrointestinal and Abdominal Cancers: Which to Use and How to Measure.

As the management of gastrointestinal malignancy has evolved, tumor response assessment has expanded from size-based assessments to those that include tumor enhancement, in addition to functional data such as those derived from PET and diffusion-weighted imaging. Accurate interpretation of tumor response therefore requires knowledge of imaging modalities used in gastrointestinal malignancy, anticancer therapies, and tumor biology. Targeted therapies such as immunotherapy pose additional considerations due to unique imaging response patterns and drug toxicity; as a consequence, immunotherapy response criteria have been developed. Some gastrointestinal malignancies require assessment with tumor-specific criteria when assessing response, often to guide clinical management (such as watchful waiting in rectal cancer or suitability for surgery in pancreatic cancer). Moreover, anatomic measurements can underestimate therapeutic response when applied to molecular-targeted therapies or locoregional therapies in hypervascular malignancies such as hepatocellular carcinoma. In these cases, responding tumors may exhibit morphologic changes including cystic degeneration, necrosis, and hemorrhage, often without significant reduction in size. Awareness of pitfalls when interpreting gastrointestinal tumor response is required to correctly interpret response assessment imaging and guide appropriate oncologic management. Data-driven image analyses such as radiomics have been investigated in a variety of gastrointestinal tumors, such as identifying those more likely to respond to therapy or recur, with the aim of delivering precision medicine. Multimedia-enhanced radiology reports can facilitate communication of gastrointestinal tumor response by automatically embedding response categories, key data, and representative images. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Convolutional LSTM model for cine image prediction of abdominal motion.

Objective.In this study, we tackle the challenge of latency in magnetic resonance linear accelerator (MR-Linac) systems, which compromises target coverage accuracy in gated real-time radiotherapy. Our focus is on enhancing motion prediction precision in abdominal organs to address this issue. We developed a convolutional long short-term memory (convLSTM) model, utilizing 2D cine magnetic resonance (cine-MR) imaging for this purpose.Approach.Our model, featuring a sequence-to-one architecture with six input frames and one output frame, employs structural similarity index measure (SSIM) as loss function. Data was gathered from 17 cine-MRI datasets using the Philips Ingenia MR-sim system and an Elekta Unity MR-Linac equivalent sequence, focusing on regions of interest (ROIs) like the stomach, liver, pancreas, and kidney. The datasets varied in duration from 1 to 10 min.Main results.The study comprised three main phases: hyperparameter optimization, individual training, and transfer learning with or without fine-tuning. Hyperparameters were initially optimized to construct the most effective model. Then, the model was individually applied to each dataset to predict images four frames ahead (1.24-3.28 s). We evaluated the model's performance using metrics such as SSIM, normalized mean square error, normalized correlation coefficient, and peak signal-to-noise ratio, specifically for ROIs with target motion. The average SSIM values achieved were 0.54, 0.64, 0.77, and 0.66 for the stomach, liver, kidney, and pancreas, respectively. In the transfer learning phase with fine-tuning, the model showed improved SSIM values of 0.69 for the liver and 0.78 for the kidney, compared to 0.64 and 0.37 without fine-tuning.Significance. The study's significant contribution is demonstrating the convLSTM model's ability to accurately predict motion for multiple abdominal organs using a Unity-equivalent MR sequence. This advancement is key in mitigating latency issues in MR-Linac radiotherapy, potentially improving the precision and effectiveness of real-time treatment for abdominal cancers.

Intra-Abdominal Epithelioid Neoplasm With EWSR1::CREB Fusions Involving the Kidney: A Clinicopathologic and Molecular Characterization With an Emphasis on Differential Diagnosis.

Soft tissue neoplasms, harboring fusions between EWSR1 and FUS with genes encoding CREB transcription factors family (ATF1, CREB1, and CREM), are an emerging heterogeneous group of mesenchymal tumors that differ significantly in morphology, immunophenotypes, and behavior. Recently, EWSR1/FUS::CREB fusions have been recognized to define a group of aggressive neoplasms of epithelioid morphology with multiple growth patterns and a striking predilection for mesothelial-lined cavities. These neoplasms presenting as a primary neoplasm of intra-abdominal visceral organs are rare, which could elicit a wide range of differential diagnoses because of their diverse morphologies and immunohistochemical profiles. We report 3 cases of intra-abdominal epithelioid neoplasms with EWSR1::CREB fusions involving the kidney. This study included 2 female patients and 1 male patient, with age at presentation ranging from 17 to 61 years (mean: 32 years). All the patients underwent radical nephrectomy without adjunctive therapies. Grossly, the tumors were large, and all were solitary masses with sizes ranging from 5.6 to 30.0 cm (mean: 14.5 cm). Histologically, the neoplasms showed infiltrating and indistinct borders and were composed predominantly of monomorphic round-to-epithelioid cells with variable amounts of pale-to-clear cytoplasm, arranged in cords, nests, and sheets and embedded in a sclerotic hyalinized stroma with variable lymphoid cuffing either intermixed or at the periphery. Notably, a hemangiopericytomatous growth pattern was commonly seen. Nuclear atypia was mild, and mitotic activity was scarce. Immunohistochemically, all 3 cases were at least focally positive for epithelial membrane antigen and keratin AE1/AE3, with 2 tumors showing focal MUC4 expression and 1 case displaying diffuse CD34 and focal CAIX positivity. Targeted RNA sequencing identified EWSR1::CREM fusion in 2 cases and EWSR1::ATF1 fusion in 1 case. Subsequent fluorescence in situ hybridization analysis confirmed the RNA sequencing results. On follow-up, 1 patient developed multiple spinal bone metastases 5 months after the surgery while the other 2 patients were free of disease 9 and 120 months after diagnosis, respectively. Our findings demonstrate that intra-abdominal epithelioid neoplasms with EWSR1::CREB fusions may rarely occur primarily in the kidney and should be included in the differential diagnosis of primary renal epithelioid mesenchymal neoplasms.

Diffuse abdominal lymphangiomatosis without tumoral masses: a case report.

Diffuse abdominal lymphangiomatosis is a rare and complex disease. It typically presents with non-specific gastrointestinal symptoms and characteristic cystic lesions or tumoral masses on imaging based on the literature to date. This report presents the rare case of a young man with an atypical form of diffuse abdominal lymphangiomatosis in the complete absence of cystic lesions or lymphangioma tumoral masses, thus presenting a unique diagnostic challenge. It was successively treated by surgery, gastric electrical stimulator, sirolimus, and imatinib.

Comparison of lung aeration loss in open abdominal oncologic surgeries after ventilation with electrical impedance tomography-guided PEEP versus conventional PEEP: a pilot feasibility study.

BACKGROUND: Existing literature lacks high-quality evidence regarding the ideal intraoperative positive end-expiratory pressure (PEEP) to minimize postoperative pulmonary complications (PPCs). We hypothesized that applying individualized PEEP derived from electrical impedance tomography would reduce the severity of postoperative lung aeration loss, deterioration in oxygenation, and PPC incidence. METHODS: A pilot feasibility study was conducted on 36 patients who underwent open abdominal oncologic surgery. The patients were randomized to receive individualized PEEP or conventional PEEP at 4 cmH2O. The primary outcome was the impact of individualized PEEP on changes in the modified lung ultrasound score (MLUS) derived from preoperative and postoperative lung ultrasonography. A higher MLUS indicated greater lung aeration loss. The secondary outcomes were the PaO2/FiO2 ratio and PPC incidence. RESULTS: A significant increase in the postoperative MLUS (12.0 ± 3.6 vs 7.9 ± 2.1, P < 0.001) and a significant difference between the postoperative and preoperative MLUS values (7.0 ± 3.3 vs 3.0 ± 1.6, P < 0.001) were found in the conventional PEEP group, indicating increased lung aeration loss. In the conventional PEEP group, the intraoperative PaO2/FiO2 ratios were significantly lower but not the postoperative ratios. The PPC incidence was not significantly different between the groups. Post-hoc analysis showed the increase in lung aeration loss and deterioration of intraoperative oxygenation correlated with the deviation from the individualized PEEP. CONCLUSIONS: Individualized PEEP appears to protect against lung aeration loss and intraoperative oxygenation deterioration. The advantage was greater in patients whose individualized PEEP deviated more from the conventional PEEP.

Seek and ye shall find: The utility of perioperative VTE screening in high-risk oncologic patients undergoing abdominopelvic surgery.

BACKGROUND AND OBJECTIVE: The aim of this study was to evaluate the prevalence and risk factors associated with perioperative venous thromboembolism (VTE) in patients undergoing major oncologic surgery using an epidural catheter (EC) for postoperative analgesia with mechanical prophylaxis and without chemoprophylaxis. METHODS: Six hundred and twenty-six patients undergoing major oncologic surgery from 2009 to 2023 were evaluated. VTE was defined as deep vein thrombosis above the level of the knee. Lower extremity venous duplexes (LEVDs) were done preoperatively and postoperatively after the EC was removed. All patients received mechanical thromboprophylaxis, but not chemical prophylaxis, while the EC was in place. A generalized linear multivariable model was constructed to identify risk factors that predict pre and postoperative VTE. RESULTS: 29/626 patients (4.6%) were found to have preoperative VTE. 16/626 (2.6%) were found to have a postoperative VTE when their preoperative LEVD was negative. In comparison to patients without preoperative VTE, those with VTE were more likely to be male, anticoagulated, and have a history of coronary artery disease. Patients in the postoperative VTE group were older, male, anticoagulated, and had a history of VTE. On multivariable analysis, previous history of VTE was the risk factor most strongly associated with both pre and postoperative VTE. CONCLUSION: Oncologic patients undergoing elective abdominopelvic surgery with epidural analgesia should be screened in the perioperative setting with LEVD to identify VTE and possibly prevent PE.

Technical Considerations in Surgical Resection of Desmoplastic Small Round Cell Tumors.

Abdominal metastatic disease is a nearly universal feature of Desmoplastic Small Round Cell Tumor. The presence of this large tumor burden can be dissuasive to surgeons. Aggressive attempts at resection of all of the dozens to hundreds of nodules in the abdomen are often fraught with difficulty. This author has operated on over 200 patients with Desmoplastic Small Round Cell Tumor and offers technical considerations that aid in complete removal of all intraabdominal tumors (sarcomatosis) with an organ sparing approach. The most challenging portion of the operation is resection of the pelvic tumor in the pouch of Douglas without removing either the bladder or the rectum. These tumors are almost always large and adherent to the bladder and rectum. The desired result should be a partial peritonectomy without any evidence of gross, visible disease.

Initial validation of a diaphragm tracking system for multiple breath-hold volumetric modulated arc therapy of abdominal tumors: A phantom study.

BACKGROUND: The breath-hold radiotherapy has been increasingly used to mitigate interfractional and intrafractional breathing impact on treatment planning and beam delivery. Previous techniques include body surface measurements or radiopaque metal markers, each having known disadvantages. PURPOSE: We recently proposed a new markerless technique without the disadvantages, where diaphragm was registered between DRR and fluoroscopic x-ray projection images every 180 ms during VMAT delivery. An initial validation of the proposed diaphragm tracking system (DiaTrak) was performed using a chest phantom to evaluate its characteristics. METHODS: Diaphragm registration was performed between DRR and projection streaming kV x-ray images of a chest phantom during VMAT delivery. Streaming data including the projection images and the beam angles were transferred from a linac system to an external PC, where the diaphragm registration accuracy and beam-off latency were measured based on image cross correlation between the DRR and the projection images every 180 ms. RESULTS: It was shown that the average of the beam-off latency was 249.5 ms and the average of the diaphragm registration error was 0.84 mm CONCLUSIONS: Initial validation of the proposed DiaTrak system for multiple breath-hold VMAT of abdominal tumors has been successfully completed with a chest phantom. The resulting beam-off latency and the diaphragm registration error were regarded clinically acceptable.