Volume-based 18F-FDG PET/CT predicts prognosis and outcome of active surveillance for intra-abdominal desmoid tumor.

PURPOSE: Desmoid tumor (DT) is a rare monoclonal, fibroblastic proliferation characterized by a variable and often unpredictable clinical course. Initial active surveillance is recommended by current guideline, and surgery is one of the main therapies for DT. Predicting the prognosis and outcome of active surveillance for intra-abdominal DT is pressing issue. METHODS: The study included eighteen patients with intra-abdominal DT. Metabolic tumor volume (MTV), total lesion glycolysis (TLG), and maximum standardized uptake value (SUVmax) were measured. We analyzed their relationship with the outcome of active surveillance, as well as clinical, prognostic, and pathological data. RESULTS: The MTV and TLG of recurrent DT were significantly higher than those of non-recurrent DT (P < 0.001 and P = 0.00, respectively). The ROC curve suggested that the appropriate cutoff values for distinguishing recurrent DT from non-recurrent DT were 760.8 for MTV (sensitivity = 1, specificity = 0.857 and AUC = 0.929), and 1318.4 for TLG (sensitivity = 1, specificity = 0.786, and AUC = 0.911). The cutoff values of MTV and TLG significantly correlated with PFS using the Kaplan-Meier method (P = 0.002 and P = 0.007, respectively). MTV and TLG could distinguish DTs with subsequent progression from stable ones (P = 0.004 and P = 0.004, respectively). The ROC curve suggested that the appropriate cutoff values for distinguishing DTs with subsequent progression from stable ones were 197.1 for MTV (sensitivity = 0.9, specificity = 1, and AUC = 0.900), and 445.45 for TLG (sensitivity = 0.9, specificity = 1, and AUC = 0.900). CONCLUSION: Volume-based 18F-FDG-PET can predict prognosis of intra-abdominal DT. MTV and TLG can predict the outcome of active surveillance for intra-abdominal DT. MTV and TLG can potentially be predictors of surgical risk and difficulty.

Preoperative assessment of retroperitoneal Liposarcoma using volume-based 18F-FDG PET/CT: implications for surgical strategy and prognosis.

PURPOSE: Retroperitoneal liposarcoma (RLPS) poses a challenging scenario for surgeons due to its unpredictable biological behavior. Surgery remains the primary curative option for RLPS; however, the need for additional information to guide surgical strategies persists. Volume-based 18F-FDG PET/CT may solve this issue. METHODS: We analyzed data from 89 RLPS patients, measuring metabolic tumor volume (MTV), total lesion glycolysis (TLG), and maximum standardized uptake value (SUVmax) and explored their associations with clinical, prognostic, and pathological factors. RESULTS: MTV, TLG of multifocal and recurrent RLPS were significantly higher than unifocal and primary ones (P < 0.001, P < 0.001, P = 0.003 and P = 0.002, respectively). SUVmax correlated with FNCLCC histological grade, mitotic count and Ki-67 index (P for G1/G2 = 0.005, P for G2/G3 = 0.017, and P for G1/G3 = 0.001, P < 0.001 and P = 0.024, respectively). MTG, TLG and SUVmax of WDLPS were significantly lower than DDLPS and PLPS (P for MTV were 0.009 and 0.022, P for TLG were 0.028 and 0.048, and P for SUVmax were 0.027 and < 0.001, respectively). Multivariable Cox analysis showed that MTV > 457.65 (P = 0.025), pathological subtype (P = 0.049) and FNCLCC histological grade (P = 0.033) were related to overall survival (OS). CONCLUSIONS: Our findings indicate that MTV is an independent prognostic factor for RLPS, while MTV, TLG, and SUVmax can preoperatively predict multifocal lesions, histological grade, and pathological subtype. Volume-based 18F-FDG PET/CT offers valuable information to aid in the decision-making process for RLPS surgical strategies.

Cytoreductive surgery offers prognostic benefits in metastatic gastrointestinal stromal tumors with generalized progression following imatinib therapy: a single institute retrospective study.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Distant metastasis has been detected in approximately 50% of GIST patients at the first diagnosis. The surgical strategy for metastatic GIST with generalized progression (GP) after imatinib therapy remains unclear. METHODS: We recruited 15 patients with imatinib-resistant metastatic GIST. They received cytoreductive surgery (CRS) for tumor rupture, intestinal obstruction and gastrointestinal bleeding. We collected clinical, pathological and prognostic data for analyses. RESULTS: OS and PFS after R0/1 CRS were 56.88 ± 3.47 and 26.7 ± 4.12 months, respectively, when compared with 26 ± 5.35 and 5 ± 2.78 months after R2 CRS (P = 0.002 and P < 0.001, respectively). The OS of patients from the initiation of imatinib in the R0/1 group was 133.90 ± 15.40 months when compared with 59.80 ± 10.98 months in the R2 CRS group. There were two significant grade III complications after 15 operations (13.3%). No patient underwent reoperation. In addition, no perioperative death occurred. CONCLUSIONS: R0/1 CRS is highly probable to provide prognostic benefits for patients with metastatic GIST who experience GP following imatinib treatment. An aggressive surgical strategy for achieving R0/1 CRS can be deemed safe. If applicable, R0/1 CRS should be carefully considered in imatinib-treated patients with GP metastatic GIST.

Short- and long-term surgical outcomes of pancreatic resection for retroperitoneal sarcoma: A long-term single-center experience of 90 cases.

BACKGROUND AND OBJECTIVES: Resection of retroperitoneal sarcoma (RPS) en bloc with pancreas is challenging and controversial. This single-center retrospective study aimed to analyze the impact of pancreatic resection (PR) and its different types on short- and long-term outcomes in patients with RPS. METHODS: Data from 242 consecutive patients with RPS who underwent surgical treatment at the Peking University Cancer Hospital Sarcoma Center between January 2010 and February 2021 were analyzed. Out of these, 90 patients underwent PR, including pancreaticoduodenectomy (PD) in 31 and distal pancreatectomy (DP) in 59. RESULTS: Patients in the PR group had a higher major morbidity (37.8% vs. 14.5%) and mortality (8.9% vs. 1.3%) than those in the non-PR group, with a similar 5-year overall survival (OS) rate (46.9% vs. 53.6%). Patients in the PD and DP groups had a slight difference in major morbidity (48.4% vs. 32.2%), mortality (6.4% vs. 10.2%), and 5-year OS rates (43.3% vs. 49.3%). The PR type was not an independent risk factor for major morbidity or OS. CONCLUSIONS: PR in RPS resection was associated with increased morbidity and mortality with minimal influence on survival. Patients with RPS undergoing PD and DP showed slight differences in terms of safety and OS.

Abdominoinguinal approach in en bloc resection of retroperitoneal sarcoma involving iliac vessels with graft interposition.

Background: Retroperitoneal sarcomas (RPSs) located in the lower abdominal quadrants involving iliac vessels are difficult to manage. This study introduced a 5-step method for en bloc resection with graft interposition using the abdominoinguinal approach and evaluated its efficacy and safety. Methods: Data of 24 consecutive patients who met the inclusion criteria from 272 patients with RPS who underwent surgical treatment between April 2015 and April 2022 were retrospectively collected and analyzed. Results: The patients underwent left- or right-sided abdominoinguinal incision. In all patients, the abdominoinguinal approach provided good exposure, and complete resection was achieved. Iliac artery+vein, vein, and artery resection and replacement by graft were performed in 70.8%, 25.0%, and 4.2% of patients, respectively. Additional resected organs mainly included the colon, ureter, bladder, kidney, and abdominal wall. The median number of organs resected was 5. In 37.5% of patients, reconstruction of the lower abdominal wall and inguinal ligament was performed using a mesh. Venous graft thrombosis occurred in 21.7% of patients, while no patient had pulmonary embolism or arterial occlusion. Major complications occurred in 20.8% of patients, and no 30-day mortality was observed. The estimated 5-year local recurrence and distant metastasis rates were 54.4% and 22.1%, respectively, with a median recurrence-free survival of 27 months. Conclusions: En bloc resection of RPS involving iliac vessels with graft interposition using the abdominoinguinal approach is feasible and advantageous. Good complete resection rate and safety can be achieved. The long-term survival benefit of this surgical approach should be verified by further large-scale prospective controlled studies.

Prediction of Histologic Subtype and FNCLCC Grade by SUVmax Measured on 18F-FDG PET/CT in Patients with Retroperitoneal Liposarcoma.

This study aimed to evaluate the usefulness of maximum standardized uptake value (SUVmax) on 18F-fluorodeoxyglucose positron emission tomography with computed tomography (18F-FDG PET/CT) in differentiating the subtypes and tumor grades of retroperitoneal liposarcoma (RPLS). The data of RPLS patients who underwent surgical resection from November 2013 to December 2019 at the sarcoma center of our institute were reviewed. The demographics, clinical features, and SUVmax of 84 patients who underwent preoperative 18F-FDG PET/CT scans were analyzed. Of these, 19 patients (22.6%) were with well-differentiated liposarcoma (WDLPS), 60 patients (71.4%) were with dedifferentiated liposarcoma (DDLPS), and 5 patients (6.0%) were with pleomorphic liposarcoma (PMLPS). The median SUVmax of WDLPS, DDLPS, and PMLPS groups was 2.8 (IQR: 1.9-3.2), 6.2 (IQR: 4.1-11.3), and 4.5 (IQR: 4.0-7.4). The ROC curve suggested 3.8 as an approximate cutoff value of SUVmax for distinguishing WDLPS and non-WDLPS (sensitivity = 0.769; specificity = 0.895). The median SUVmax for FNCLCC Grades 1, 2, and 3 of RPLS was 2.5 (IQR: 1.9-3.2), 4.5 (IQR: 3.2-6.7), and 9.0 (IQR: 6.0-13.3). The ROC curves suggest that SUVmax of ≤3.8 and >5.3 can be used for predicting FNCLCC Grades 1 and 3, respectively. The result showed that 18F-FDG PET/CT exhibited high sensitivity and specificity for identifying the subtypes and FNCLCC grades of RPLS. Additionally, 18F-FDG PET/CT might be a useful complementary imaging modality for guiding suitable biopsy location of RPLS.

Pancreaticoduodenectomy for Retroperitoneal Sarcomas: A Mono-Institutional Experience in China.

BACKGROUND: En bloc resection of retroperitoneal sarcoma (RPS) with adjacent organs such as pancreatic head and duodenum is challenging for surgeons. This mono-institutional study aims to evaluate the feasibility, safety, and outcome of performing pancreaticoduodenectomy (PD) during RPS resection. METHODS: The clinical data of RPS patients who underwent PD at the Sarcoma Center of Peking University Cancer Hospital from January 2011 to December 2019 was collected and analyzed. RESULTS: Twenty-seven patients out of a total of 264 surgically treated RPS underwent PD. The main pathological subtype was liposarcoma. All patients received concomitant resection of a median of three additional organs (range: 1-5), including 11 patients (40.7%) who underwent inferior vena cava resection and one patient who underwent segmental superior mesenteric-portal vein resection. Microscopic tumor infiltration to the duodenum or pancreas was observed in 81.5% of patients. Major complications occurred in 40.7% of patients; the reoperation rate was 22.2%. One patient (3.7%) died from liver abscess postoperatively. During a median follow-up of 18.9 months, 15 patients (55.6%) developed locally recurrent disease; two patients (7.4%) also had pulmonary metastases additionally. Twelve patients (44.4%) died from local relapse eventually. CONCLUSION: PD during RPS resection is feasible, and it may be necessary to achieve complete resection. However, considering the complexity and risk, it should be performed by an experienced surgical team. The long-term survival benefit of this procedure should be verified by further large-scale multi-institutional studies.

Use of 18F-FDG-PET/CT for Retroperitoneal/Intra-Abdominal Soft Tissue Sarcomas.

Rationale: To assess the diagnostic value of 18F-FDG-PET/CT for different retroperitoneal soft tissue sarcomas (STS) and other similar tumors. To analyze the predictive value of 18F-FDG-PET/CT for histological grade and main prognostic factors. Methods: 195 patients with 44 different diseases have been included. Relationship between SUVmax, Clinical, pathological, and prognostic information has been analyzed. Results: Malignant tumors do not show higher SUVmax than benign ones (P=0.443). We divided all 44 different diseases into two groups; SUVmax of group 1 is significantly higher than group 2 (P ≤ 0.001). The ROC curve suggests 4.35 is the cutoff value to distinguish groups 1 and 2 (sensitivity = 0.789; specificity = 0.736). SUVmax correlates with Ki-67 index, mitotic count, vascular resection, histological grade, and recurrent STS without considering pathological diagnosis (P=0.001, P=0.012, P=0.002, P ≤ 0.001, and P=0.037, resp.). Conclusion: 18F-FDG-PET/CT cannot simply distinguish malignant and benign tumors in retroperitoneal/intra-abdominal cavity; however, the SUVmax of malignant tumors, inflammatory pseudotumor, and PPGL group is higher than the SUVmax of benign tumors, lymph node metastasis, hematoma, and low malignant STS group. Guidance of "SUVmax location" may be helpful for biopsy and pathology dissection.

Superior mesenteric artery margin in pancreaticoduodenectomy for pancreatic adenocarcinoma.

The aim of this study is trying to describe more details of superior mesenteric artery margin in pancreaticoduodenectomy for pancreatic ductal adenocarcinoma, to evaluate biological and prognostic implications of tumor budding in this margin, and to provide more evidence for evaluation of R0 surgery in pancreaticoduodenectomy. 46 patients in 5-years period are included in this study. Immunochemistry and immunofluorescence are used to analyze tumor budding and epithelial-mesenchymal transition. Superior mesenteric artery margin might be described from four aspects including location, gross appearance, microscopic appearance and tumor budding. We find that 1mm rule for R1 surgery is more appropriate to predict prognosis (P = 0.009) than 0mm rule (P = 0.141). Expression of cytokeratin in tumor budding is significantly lower than primary tumor (P = 0.001), and it suggests that tumor budding may participate the procedure of epithelial-mesenchymal transition. High-grade tumor budding and decreasing cytokeratin of tumor budding correlate with distant metastasis and has negative influence on prognosis. So superior mesenteric artery margin might be not only an area that tumor cells may invade, but also a pathway for distant metastasis. It is necessary to evaluate superior mesenteric artery margin in pancreaticoduodenectomy for pancreatic cancer.

Location of supraorbital foramen/notch and infraorbital foramen with reference to soft- and hard-tissue landmarks.

The purpose of the present study was to determine the locations of the supraorbital foramen (SOF) and the infraorbital foramen (IOF) relative to soft- and hard-tissue landmarks. It will provide more accurate data for dental and facial surgery. Twenty embalmed adult cadavers (40 sides; 16 men, 4 women) were dissected to expose the SOFs and IOFs, and another 46 skulls (92 sides) were also measured for further study. The locations of the SOFs and IOFs were evaluated with direct and photographic measurements. The data gained were analyzed by statistical method. The horizontal distances between the SOFs/IOFs and the medial canthus to the distance between the medial canthus and the lateral canthus ratios have been measured, and their confidence intervals are 0.22 to 0.31 and 0.34 to 0.49, respectively, and their linear regression equations are EF = 0.58 CF + 25.02 (unit: mm) and EF = 0.51 DG + 24.20 (unit: mm). The vertical distance between IOFs/SOFs and the medial/lateral canthi are 25.09 ± 3.36 mm/23.91 ± 3.31 mm and 25.75 ± 3.34 mm/26.93 ± 3.88 mm, respectively. The horizontal angle between IOFs/SOFs and the medial/lateral canthi are 72.54 ± 7.13 degrees, 66.77 ± 5.17 degrees, 47.45 ± 6.57 degrees, 54.69 ± 8.38 degrees, respectively. Based on the hard tissues, The SOF localized 20.55 ± 3.24 mm medial and 13.78 ± 2.60 mm superior to the zygomaticofrontal suture. And the horizontal angle between them is 56.04 ± 6.87 degrees. The IOF localized 18.52 ± 2.30 mm medial and 30.79 ± 3.29 inferior to the zygomaticofrontal suture. The horizontal angle between them is 31.06 ± 4.33 degrees. We also found that most (96.81%) of the IOFs were located below the middle line of the zygomatic arch. These results may provide more detailed information about the locations of SOF and IOF. And they will facilitate prediction of the locations of IOF and SOF in clinical procedure.