Clinical outcomes after online adaptive MR-guided stereotactic body radiotherapy for pancreatic tumors on a 1.5 T MR-linac.

Introduction: Online adaptive magnetic resonance-guided radiotherapy (MRgRT) is a promising treatment modality for pancreatic cancer and is being employed by an increasing number of centers worldwide. However, clinical outcomes have only been reported on a small scale, often from single institutes and in the context of clinical trials, in which strict patient selection might limit generalizability of outcomes. This study presents clinical outcomes of a large, international cohort of patients with (peri)pancreatic tumors treated with online adaptive MRgRT. Methods: We evaluated clinical outcomes and treatment details of patients with (peri)pancreatic tumors treated on a 1.5 Tesla (T) MR-linac in two large-volume treatment centers participating in the prospective MOMENTUM cohort (NCT04075305). Treatments were evaluated through schematics, dosage, delivery strategies, and success rates. Acute toxicity was assessed until 3 months after MRgRT started, and late toxicity from 3-12 months of follow-up (FU). The EORTC QLQ-C30 questionnaire was used to evaluate the quality of life (QoL) at baseline and 3 months of FU. Furthermore, we used the Kaplan-Meier analysis to calculate the cumulative overall survival. Results: A total of 80 patients were assessed with a median FU of 8 months (range 1-39 months). There were 34 patients who had an unresectable primary tumor or were medically inoperable, 29 who had an isolated local recurrence, and 17 who had an oligometastasis. A total of 357 of the 358 fractions from all hypofractionated schemes were delivered as planned. Grade 3-4 acute toxicity occurred in 3 of 59 patients (5%) with hypofractionated MRgRT and grade 3-4 late toxicity in 5 of 41 patients (12%). Six patients died within 3 months after MRgRT; in one of these patients, RT attribution could not be ruled out as cause of death. The QLQ-C30 global health status remained stable from baseline to 3 months FU (70.5 at baseline, median change of +2.7 [P = 0.5]). The 1-year cumulative overall survival for the entire cohort was 67%, and that for the primary tumor group was 66%. Conclusion: Online adaptive MRgRT for (peri)pancreatic tumors on a 1.5 T MR-Linac could be delivered as planned, with low numbers of missed fractions. In addition, treatments were associated with limited grade 3-4 toxicity and a stable QoL at 3 months of FU.

Learning Curves of Minimally Invasive Distal Pancreatectomy in Experienced Pancreatic Centers.

Importance: Understanding the learning curve of a new complex surgical technique helps to reduce potential patient harm. Current series on the learning curve of minimally invasive distal pancreatectomy (MIDP) are mostly small, single-center series, thus providing limited data. Objective: To evaluate the length of pooled learning curves of MIDP in experienced centers. Design, Setting, and Participants: This international, multicenter, retrospective cohort study included MIDP procedures performed from January 1, 2006, through June 30, 2019, in 26 European centers from 8 countries that each performed more than 15 distal pancreatectomies annually, with an overall experience exceeding 50 MIDP procedures. Consecutive patients who underwent elective laparoscopic or robotic distal pancreatectomy for all indications were included. Data were analyzed between September 1, 2021, and May 1, 2022. Exposures: The learning curve for MIDP was estimated by pooling data from all centers. Main Outcomes and Measures: The learning curve was assessed for the primary textbook outcome (TBO), which is a composite measure that reflects optimal outcome, and for surgical mastery. Generalized additive models and a 2-piece linear model with a break point were used to estimate the learning curve length of MIDP. Case mix-expected probabilities were plotted and compared with observed outcomes to assess the association of changing case mix with outcomes. The learning curve also was assessed for the secondary outcomes of operation time, intraoperative blood loss, conversion to open rate, and postoperative pancreatic fistula grade B/C. Results: From a total of 2610 MIDP procedures, the learning curve analysis was conducted on 2041 procedures (mean [SD] patient age, 58 [15.3] years; among 2040 with reported sex, 1249 were female [61.2%] and 791 male [38.8%]). The 2-piece model showed an increase and eventually a break point for TBO at 85 procedures (95% CI, 13-157 procedures), with a plateau TBO rate at 70%. The learning-associated loss of TBO rate was estimated at 3.3%. For conversion, a break point was estimated at 40 procedures (95% CI, 11-68 procedures); for operation time, at 56 procedures (95% CI, 35-77 procedures); and for intraoperative blood loss, at 71 procedures (95% CI, 28-114 procedures). For postoperative pancreatic fistula, no break point could be estimated. Conclusion and Relevance: In experienced international centers, the learning curve length of MIDP for TBO was considerable with 85 procedures. These findings suggest that although learning curves for conversion, operation time, and intraoperative blood loss are completed earlier, extensive experience may be needed to master the learning curve of MIDP.

Risk Models for Developing Pancreatic Fistula After Pancreatoduodenectomy: Validation in a Nationwide Prospective Cohort.

OBJECTIVE: To evaluate the performance of published fistula risk models by external validation, and to identify independent risk factors for postoperative pancreatic fistula (POPF). BACKGROUND: Multiple risk models have been developed to predict POPF after pancreatoduodenectomy. External validation in high-quality prospective cohorts is, however, lacking or only performed for individual models. METHODS: A post hoc analysis of data from the stepped-wedge cluster cluster-randomized Care After Pancreatic Resection According to an Algorithm for Early Detection and Minimally Invasive Management of Pancreatic Fistula versus Current Practice (PORSCH) trial was performed. Included were all patients undergoing pancreatoduodenectomy in the Netherlands (January 2018-November 2019). Risk models on POPF were identified by a systematic literature search. Model performance was evaluated by calculating the area under the receiver operating curves (AUC) and calibration plots. Multivariable logistic regression was performed to identify independent risk factors associated with clinically relevant POPF. RESULTS: Overall, 1358 patients undergoing pancreatoduodenectomy were included, of whom 341 patients (25%) developed clinically relevant POPF. Fourteen risk models for POPF were evaluated, with AUCs ranging from 0.62 to 0.70. The updated alternative fistula risk score had an AUC of 0.70 (95% confidence intervals [CI]: 0.69-0.72). The alternative fistula risk score demonstrated an AUC of 0.70 (95% CI: 0.689-0.71), whilst an AUC of 0.70 (95% CI: 0.699-0.71) was also found for the model by Petrova and colleagues. Soft pancreatic texture, pathology other than pancreatic ductal adenocarcinoma or chronic pancreatitis, small pancreatic duct diameter, higher body mass index, minimally invasive resection and male sex were identified as independent predictors of POPF. CONCLUSION: Published risk models predicting clinically relevant POPF after pancreatoduodenectomy have a moderate predictive accuracy. Their clinical applicability to identify high-risk patients and guide treatment strategies is therefore questionable.

Fistula Risk Score for Auditing Pancreatoduodenectomy: The Auditing-FRS.

OBJECTIVE: To develop a fistula risk score for auditing, to be able to compare postoperative pancreatic fistula (POPF) after pancreatoduodenectomy among hospitals. BACKGROUND: For proper comparisons of outcomes in surgical audits, case-mix variation should be accounted for. METHODS: This study included consecutive patients after pancreatoduodenectomy from the mandatory nationwide Dutch Pancreatic Cancer Audit. Derivation of the score was performed with the data from 2014 to 2018 and validation with 2019 to 2020 data. The primary endpoint of the study was POPF (grade B or C). Multivariable logistic regression analysis was performed for case-mix adjustment of known risk factors. RESULTS: In the derivation cohort, 3271 patients were included, of whom 479 (14.6%) developed POPF. Male sex [odds ratio (OR)=1.34; 95% confidence interval (CI): 1.09-1.66], higher body mass index (OR=1.07; 95% CI: 1.05-1.10), a final diagnosis other than pancreatic ductal adenocarcinoma/pancreatitis (OR=2.41; 95% CI: 1.90-3.06), and a smaller duct diameter (OR=1.43/mm decrease; 95% CI: 1.32-1.55) were independently associated with POPF. Diabetes mellitus (OR=0.73; 95% CI: 0.55-0.98) was independently associated with a decreased risk of POPF. Model discrimination was good with a C -statistic of 0.73 in the derivation cohort and 0.75 in the validation cohort (n=913). Hospitals differed in particular in the proportion of pancreatic ductal adenocarcinoma/pancreatitis patients, ranging from 36.0% to 58.1%. The observed POPF risk per center ranged from 2.9% to 25.4%. The expected POPF rate based on the 5 risk factors ranged from 11.6% to 18.0% among hospitals. CONCLUSIONS: The auditing fistula risk score was successful in case-mix adjustment and enables fair comparisons of POPF rates among hospitals.

The fear of cancer recurrence and progression in patients with pancreatic cancer.

PURPOSE: It is plausible that patients with pancreatic cancer experience fear of tumor recurrence or progression (FOP). The aim of this study was to compare FOP in patients with pancreatic cancer treated with surgical resection, palliative systemic treatment, or best supportive care (BSC) and analyze the association between quality of life (QoL) and FOP and the effect of FOP on overall survival (OS). METHODS: This study included patients diagnosed with pancreatic cancer between 2015 and 2018, who participated in the Dutch Pancreatic Cancer Project (PACAP). The association between QoL and WOPS was assessed with logistic regression analyses. OS was evaluated using Kaplan-Meier curves with the log-rank tests and multivariable Cox proportional hazard analyses adjusted for clinical covariates and QoL. RESULTS: Of 315 included patients, 111 patients underwent surgical resection, 138 received palliative systemic treatment, and 66 received BSC. Patients who underwent surgical resection had significantly lower WOPS scores (i.e., less FOP) at initial diagnosis compared to patients who received palliative systemic treatment or BSC only (P < 0.001). Better QoL was independently associated with the probability of having a low FOP in the BSC (OR 0.95, 95% CI 0.91-0.98) but not in the surgical resection (OR 0.97, 95% CI 0.94-1.01) and palliative systemic treatment groups (OR 0.97, 95% CI 0.94-1.00). The baseline WOPS score was not independently associated with OS in any of the subgroups. CONCLUSION: Given the distress that FOP evokes, FOP should be explicitly addressed by health care providers when guiding pancreatic cancer patients through their treatment trajectory, especially those receiving palliative treatment or BSC.

Hepatopancreatoduodenectomy -a controversial treatment for bile duct and gallbladder cancer from a European perspective.

BACKGROUND: Hepatopancreatoduodenectomy (HPD) is an aggressive operation for treatment of advanced bile duct and gallbladder cancer associated with high perioperative morbidity and mortality, and uncertain oncological benefit in terms of survival. Few reports on HPD from Western centers exist. The purpose of this study was to evaluate safety and efficacy for HPD in European centers. METHOD: Members of the European-African HepatoPancreatoBiliary Association were invited to report all consecutive patients operated with HPD for bile duct or gallbladder cancer between January 2003 and January 2018. The patient and tumor characteristics, perioperative and survival outcomes were analyzed. RESULTS: In total, 66 patients from 19 European centers were included in the analysis. 90-day mortality rate was 17% and 13% for bile duct and gallbladder cancer respectively. All factors predictive of perioperative mortality were patient and disease-specific. The three-year overall survival excluding 90-day mortality was 80% for bile duct and 30% for gallbladder cancer (P = 0.013). In multivariable analysis R0-resection had a significant impact on overall survival. CONCLUSION: HPD, although being associated with substantial perioperative mortality, can offer a survival benefit in patient subgroups with bile duct cancer and gallbladder cancer. To achieve negative resection margins is paramount for an improved survival outcome.

Outcomes After Minimally-invasive Versus Open Pancreatoduodenectomy: A Pan-European Propensity Score Matched Study.

OBJECTIVE: To assess short-term outcomes after minimally invasive (laparoscopic, robot-assisted, and hybrid) pancreatoduodenectomy (MIPD) versus open pancreatoduodenectomy (OPD) among European centers. BACKGROUND: Current evidence on MIPD is based on national registries or single expert centers. International, matched studies comparing outcomes for MIPD and OPD are lacking. METHODS: Retrospective propensity score matched study comparing MIPD in 14 centers (7 countries) performing ≥10 MIPDs annually (2012-2017) versus OPD in 53 German/Dutch surgical registry centers performing ≥10 OPDs annually (2014-2017). Primary outcome was 30-day major morbidity (Clavien-Dindo ≥3). RESULTS: Of 4220 patients, 729/730 MIPDs (412 laparoscopic, 184 robot-assisted, and 130 hybrid) were matched to 729 OPDs. Median annual case-volume was 19 MIPDs (interquartile range, IQR 13-22), including the first MIPDs performed in 10/14 centers, and 31 OPDs (IQR 21-38). Major morbidity (28% vs 30%, P = 0.526), mortality (4.0% vs 3.3%, P = 0.576), percutaneous drainage (12% vs 12%, P = 0.809), reoperation (11% vs 13%, P = 0.329), and hospital stay (mean 17 vs 17 days, P > 0.99) were comparable between MIPD and OPD. Grade-B/C postoperative pancreatic fistula (POPF) (23% vs 13%, P < 0.001) occurred more frequently after MIPD. Single-row pancreatojejunostomy was associated with POPF in MIPD (odds ratio, OR 2.95, P < 0.001), but not in OPD. Laparoscopic, robot-assisted, and hybrid MIPD had comparable major morbidity (27% vs 27% vs 35%), POPF (24% vs 19% vs 25%), and mortality (2.9% vs 5.2% vs 5.4%), with a fewer conversions in robot-assisted- versus laparoscopic MIPD (5% vs 26%, P < 0.001). CONCLUSIONS: In the early experience of 14 European centers performing ≥10 MIPDs annually, no differences were found in major morbidity, mortality, and hospital stay between MIPD and OPD. The high rates of POPF and conversion, and the lack of superior outcomes (ie, hospital stay, morbidity) could indicate that more experience and higher annual MIPD volumes are needed.

Nationwide trends in incidence, treatment and survival of pancreatic ductal adenocarcinoma.

BACKGROUND: In recent years, new treatment options have become available for pancreatic ductal adenocarcinoma (PDAC) including 5-fluorouracil, leucovorin, irinotecan and oxaliplatin. The impact hereof has not been assessed in nationwide cohort studies. This population-based study aimed to investigate nationwide trends in incidence, treatment and survival of PDAC. MATERIALS AND METHODS: Patients with PDAC (1997-2016) were included from the Netherlands Cancer Registry. Results were categorised by treatment and by period of diagnosis (1997-2000, 2001-2004, 2005-2008, 2009-2012 and 2013-2016). Kaplan-Meier survival analysis was used to calculate overall survival. RESULTS: In a national cohort of 36,453 patients with PDAC, the incidence increased from 12.1 (1997-2000) to 15.3 (2013-2016) per 100,000 (p < 0.001), whereas median overall survival increased from 3.1 to 3.8 months (p < 0.001). Over time, the resection rate doubled (8.3%-16.6%, p-trend<0.001), more patients received adjuvant chemotherapy (3.0%-56.2%, p-trend<0.001) and 3-year overall survival following resection increased (16.9%-25.4%, p < 0.001). Over time, the proportion of patients with metastatic disease who received palliative chemotherapy increased from 5.3% to 16.1% (p-trend<0.001), whereas 1-year survival improved from 13.3% to 21.2% (p < 0.001). The proportion of patients who only received supportive care decreased from 84% to 61% (p-trend<0.001). CONCLUSION: The incidence of PDAC increased in the past two decades. Resection rates and use of adjuvant or palliative chemotherapy increased with improved survival in these patients. In all patients with PDAC, however, the survival benefit of 3 weeks is negligible because the majority of patients only received supportive care.

Computed tomography findings after radiofrequency ablation in locally advanced pancreatic cancer.

PURPOSE: The purpose of the study was to provide a systematic evaluation of the computed tomography(CT) findings after radiofrequency ablation (RFA) in locally advanced pancreatic cancer(LAPC). METHODS: Eighteen patients with intra-operative RFA-treated LAPC were included in a prospective case series. All CT-scans performed prior to RFA and 1 week and 3 months of post-RFA, according to standard regimen, were assessed by two radiologists in consensus, using standardized radiological scoring lists. RESULTS: 51 CT-scans were assessed. One week after RFA, the ablation zone was visible in all patients as a (partially) sharply defined (83%), heterogeneous area (94%). At 3 months of follow-up, the ablation zone was completely invaded by tumor in 67% of patients and still present, but decreased in 33%. In two patients (11%), local thrombosis and/or occlusion of the superior mesenteric vein occurred. The occlusions persisted without clinical consequences and the thrombosis disappeared. A peripancreatic fluid collection was visible 1 week after RFA in 3 patients, wherein the ablation zone extended ventrally outside of the pancreas. CONCLUSIONS: Directly after RFA for LAPC, a well-defined ablation zone is visible on CT-imaging. This ablation zone is usually replaced by tumor ingrowth after 3 months. Moreover, the ablation zone regularly included vascular structures, with rare asymptomatic venous occlusion or thrombosis and without adverse effects on arteries.

Clinical and pathological outcomes after irreversible electroporation of the pancreas using two parallel plate electrodes: a porcine model.

BACKGROUND: Irreversible electroporation (IRE) by inserting needles around the tumor as treatment for locally advanced pancreatic cancer entails several disadvantages, such as incomplete ablation due to field inhomogeneity, technical difficulties in needle placement and a risk of pancreatic fistula development. This experimental study evaluates outcomes of IRE using paddles in a porcine model. METHODS: Six healthy pigs underwent laparotomy and were treated with 2 separate ablations (in head and tail of the pancreas). Follow-up consisted of clinical and laboratory parameters and contrast-enhanced computed tomography (ceCT) imaging. After 2 weeks, pancreatoduodenectomy was performed for histology and the pigs were terminated. RESULTS: All animals survived 14 days. None of the animals developed signs of infection or significant abdominal distention. Serum amylase and lipase peaked at day 1 postoperatively in all pigs, but normalized without signs of pancreatitis. On ceCT-imaging the ablation zone was visible as an ill-defined, hypodense lesion. No abscesses, cysts or ascites were seen. Histology showed a homogenous fibrotic lesion in all pigs. CONCLUSION: IRE ablation of healthy porcine pancreatic tissue using two plate electrodes is feasible and safe and creates a homogeneous fibrotic lesion. IRE-paddles should be tested on pancreatic adenocarcinoma to determine the effect in cancer tissue.

A Giant Brunneroma Causing Gastrointestinal Bleeding and Severe Anemia Requiring Transfusion and Surgery.

Brunner's gland hamartoma, also called hyperplasia, adenoma, and Brunneroma, is an extremely rare benign proliferative lesion of Brunner's glands in the duodenum. While being mostly small and asymptomatic, they can result in gastrointestinal bleeding and obstruction. We report the case of a 54-year-old man presenting with melena and severe anemia requiring blood transfusion. CT scans showed a large mass of 8 cm in diameter, presumably arising in the duodenum. Endoscopic biopsies were not conclusive. As we were unable to determine the nature of the mass preoperatively and due to the severe symptoms, its size, and the uncertain malignant potential, a classic Whipple procedure was performed. The resected specimen showed extensive proliferation of Brunner's glands without signs of malignancy.

Robot-assisted laparoscopic liver resection: a systematic review and pooled analysis of minor and major hepatectomies.

BACKGROUND: Robotic surgery has been introduced to overcome the limitations of conventional laparoscopy. A systematic review and meta-analysis were performed to assess the safety and feasibility for three subgroups of robot-assisted laparoscopic liver resection: (i) minor resections of easily accessible segments: 2/3, 4B, 5, 6, (ii) minor resections of difficult located segments: 1, 4A, 7, 8 and (iii) major resections: ≥ 4 segments. METHODS: A systematic search was performed in PubMed, EMBASE and Cochrane Library. RESULTS: Twelve observational, mostly retrospective studies reporting on 363 patients were included. Data were pooled and analyzed. For subgroup (i) (n = 81) the weighted mean operative time was 215 ± 65 min. One conversion (1%) to laparotomy was needed. Weighted mean operative time for subgroup (ii) (n = 17) was 220 ± 60 min. No conversions were needed. For subgroup (iii) (n = 99) the weighted mean operative time was 405 ± 100 min. In this subgroup 8 robotic procedures (8%) were converted to open surgery. CONCLUSION: Data show that robot-assisted laparoscopic liver resection is feasible in minor resections of all segments and major resections. Larger, prospective studies are warranted to compare the possible advantages of robot-assisted surgery with conventional laparoscopy and open surgery.

MRI-based tumor motion characterization and gating schemes for radiation therapy of pancreatic cancer.

BACKGROUND AND PURPOSE: To characterize pancreatic tumor motion and to develop a gating scheme for radiotherapy in pancreatic cancer. MATERIALS AND METHODS: Two cine MRIs of 60s each were performed in fifteen pancreatic cancer patients, one in sagittal direction and one in coronal direction. A Minimum Output Sum of Squared Error (MOSSE) adaptive correlation filter was used to quantify tumor motion in craniocaudal, lateral and anteroposterior directions. To develop a gating scheme, stability of the breathing phases was examined and a gating window assessment was created, incorporating tumor motion, treatment time and motion margins. RESULTS: The largest tumor motion was found in craniocaudal direction, with an average peak-to-peak amplitude of 15mm (range 6-34mm). Amplitude of the tumor in the anteroposterior direction was on average 5mm (range 1-13mm). The least motion was seen in lateral direction (average 3mm, range 2-5mm). The end exhale position was the most stable position in the breathing cycle and tumors spent more time closer to the end exhale position than to the end inhale position. On average, a margin of 25% of the maximum craniocaudal breathing amplitude was needed to achieve full target coverage with a duty cycle of 50%. When reducing the duty cycle to 50%, a margin of 5mm was sufficient to cover the target in 11 out of 15 patients. CONCLUSION: Gated delivery for radiotherapy of pancreatic cancer is best performed around the end exhale position as this is the most stable position in the breathing cycle. Considerable margin reduction can be established at moderate duty cycles, yielding acceptable treatment efficiency. However, motion patterns and amplitude do substantially differ between individual patients. Therefore, individual treatment strategies should be considered for radiotherapy in pancreatic cancer.

Primary lymphoma of the liver - A complex diagnosis.

A 59-year-old woman presented with the clinical symptoms and radiologic investigations of a liver lesion suspect of metastasis. However, postoperative histopathology revealed a primary hepatic lymphoma (PHL). The case of a patient with a solitary PHL, which was treated by resection and subsequent chemotherapy, will be discussed with a short overview of the literature.