Extrapancreatic neural plexus invasion by carcinomas of the pancreatic head region: evaluation using thin-section helical CT

Preoperative diagnosis of perineural invasion in patients with periampullary carcinoma by MSCT imaging: preliminary observations and clinical implications

PURPOSE

The aim of this study was to investigate the value of multi-slice computed tomography (MSCT) in preoperatively diagnosing perineural invasion (PNI) of periampullary carcinoma (PAC).

METHODS

Of 81 patients pathologically diagnosed as PAC, 73 patients were included. Their clinical documents and preoperative upper abdominal enhanced MSCT images were retrospectively reviewed to analyse clinical characteristics and MSCT features. MSCT features included tumor size, classification of fat tissue around celiac trunk and superior mesenteric artery. Chi-square test, Mann-Whitney U test or Fisher's exact test were used to compare the differences between PNI group and Non-PNI group. ROC analysis was performed to evaluate diagnostic efficiency for PAC PNI.

RESULTS

There were significant differences in some clinical characteristics and MSCT features. PAC PNI patients had significantly higher CA19-9 levels, higher CEA levels, larger tumor size and higher classification of fat tissue around celiac trunk than Non-PNI patients (All P values < 0.05). In univariate analysis, tumor size had the highest AUC as 0.806, fat tissue around celiac trunk and CEA had the highest specificity as 100% (P < 0.001). In multivariate analysis, classification of fat tissue around celiac trunk incorporated with tumor size, CA19-9, CEA, age and sex, showed the highest AUC as 0.939, with specificity of 95.0% and sensitivity of 90.4% (P < 0.001).

CONCLUSION

PAC PNI could be diagnosed preoperatively by evaluating abdominal enhanced MSCT images with high accuracy, combined with serum tumor marker could be more helpful.

Multiagent Chemotherapy and Stereotactic Body Radiation Therapy in Patients with Unresectable Pancreatic Adenocarcinoma: A Prospective Nonrandomized Controlled Trial

PURPOSE

In a prospective multicenter study, gemcitabine monotherapy followed by stereotactic body radiation therapy (SBRT) was well tolerated with outcomes comparable to chemoradiation for locally advanced pancreatic cancer (LAPC). Recent trials have reported improved survival with multiagent chemotherapy (MA-CTX) alone. This prospective trial explored whether SBRT could be safely delivered after MA-CTX. Herein, we report the long-term outcomes of adding SBRT after MA-CTX in LAPC patients and evaluate whether genetic profiles of specimens obtained before SBRT influence outcomes.

METHODS AND MATERIALS

This prospective nonrandomized controlled phase 2 trial enrolled 44 LAPC and 4 locally recurrent patients after multidisciplinary evaluation between 2012 and 2015 at a high-volume pancreatic cancer center. For induction CTX, most received modified FOLFIRINOX (mFFX), or gemcitabine and nab-paclitaxel (GnP) followed by 5-fraction SBRT for all. During fiducial placement, biopsies were obtained with DNA extracted for targeted sequencing using the Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets platform.

RESULTS

Median induction CTX duration was ≥4 months, and 31 patients received mFFX (65%). Among 44 LAPC patients, 17 (39%) were surgically explored, and 12 of 16 (75%) achieved a R0 resection. Median overall survival (mOS) was 20.2 and 14.6 months from diagnosis and SBRT, respectively. One- and 2-year OS from SBRT was 58% and 28%. The mOS after resection was 28.6 and 22.4 months from diagnosis and SBRT, respectively. Median local progression-free survival was 23.9 and 15.8 months from diagnosis and SBRT, respectively. The mOS for pre-SBRT CA 19-9 ≤180 U/mL versus >180 was 23.1 and 11.3 months, respectively (hazard ratio, 0.53; P = .04). Only 1 patient (2.1%) had late grade ≥2 gastrointestinal toxic effects attributable to SBRT. Despite significant pretreatment with chemotherapy, 88% of tumor specimens were effectively sequenced; survival outcomes were not significantly associated with specific mutational patterns. Quality of life was prospectively collected pre- and post-SBRT with the EORTC QLQ-C30 and PAN26 questionnaires showing no significant change.

CONCLUSIONS

SBRT was safely administered with MA-CTX with minimal toxicity. A high proportion of LAPC patients underwent R0 resection with favorable survival outcomes.

Location, Location, Location: What Should be Targeted Beyond Gross Disease for Localized Pancreatic Ductal Adenocarcinoma? Proposal of a Standardized Clinical Tumor Volume for Pancreatic Ductal Adenocarcinoma of the Head: The "Triangle Volume"

PURPOSE

In patients with borderline resectable or locally advanced pancreatic adenocarcinoma (BRPC/LAPC), local failure rates after resection remain significant, even in the setting of neoadjuvant chemotherapy and radiation. Suboptimal local control may relate to variable radiation target delineation, as no consensus exists around clinical tumor volume (CTV) design in this context. In the surgical literature, recent attention has been given to the "triangle" volume (TV) as a source of subclinical, residual disease. To understand whether the TV can inform optimal CTV design, we mapped locoregional failures after resection in a large cohort of patients with BRPC/LAPC and compared locations of failure to the TV.

METHODS AND MATERIALS

Patients with BRPC/LAPC of the head or neck diagnosed between 2016 AND 2019 who developed locoregional failure after surgery, neoadjuvant chemotherapy, and radiation were identified. Descriptive statistics were generated to report the frequency of locoregional failures located within the TV and the frequency of new vascular involvement at time of failure, compared with vascular involvement at diagnosis. Additionally, dosimetric coverage of the TV with the preoperative radiation plan that had been used was assessed.

RESULTS

In 31 patients who experienced locoregional failure, the centroid of failure was located within the TV in 28 cases (90%). Extent of vascular involvement at time of locoregional failure included vasculature that had not been involved at diagnosis in 13 cases (42%). The preoperative radiation plan that had been used provided a median V33 Gy and V25 Gy of the TV of only 53% (interquartile range, 34%-72%) and 70% (IQR, 48%-85%), respectively.

CONCLUSIONS

The TV encompassed the vast majority of locoregional failures, but dosimetric coverage of the TV was poor when only targeting gross disease and the full circumference of involved vasculature. As such, the TV may better serve as a basis for CTV design in patients with BRPC/LAPC undergoing neoadjuvant radiation.

Neoadjuvant Stereotactic Body Radiotherapy After Upfront Chemotherapy Improves Pathologic Outcomes Compared With Chemotherapy Alone for Patients With Borderline Resectable or Locally Advanced Pancreatic Adenocarcinoma Without Increasing Perioperative Toxicity

BACKGROUND

Patients with borderline resectable pancreatic cancer (BRPC) or locally advanced pancreatic cancer (LAPC) are at high risk of margin-positive resection. Neoadjuvant stereotactic body radiation therapy (SBRT) may help sterilize margins, but its additive benefit beyond neoadjuvant chemotherapy (nCT) is unclear. The authors report long-term outcomes for BRPC/LAPC patients explored after treatment with either nCT alone or nCT followed by five-fraction SBRT (nCT-SBRT).

METHODS

Patients with BRPC or LAPC from 2011 to 2016 who underwent resection after nCT alone or nCT-SBRT were retrospectively reviewed. Baseline characteristics were compared, and the propensity score with inverse probability weighting (IPW) was used to compare pathologic/survival outcomes.

RESULTS

Of 198 patients, 76 received nCT, and 122 received nCT-SBRT. The nCT-SBRT cohort had a higher proportion of LAPC (53% vs 22%; p < 0.001). The duration of nCT was longer for nCT-SBRT (4.6 vs 2.9 months; p = 0.03), but adjuvant chemotherapy was less frequently administered (53% vs 67.1%; p < 0.001). Adjuvant radiation was administered to 30% of the nCT patients. The nCT-SBRT regimen more frequently achieved negative margins (92% vs 70%; p < 0.001), negative nodes (59% vs 42%; p < 0.001), and pathologic complete response (7% vs 0%; p = 0.02). In the multivariate analysis, nCT-SBRT remained associated with R0 resection (p < 0.001). The nCT-SBRT cohort experienced no significant difference in median overall survival (OS) (22.1 vs 24.5 months), local progression-free survival (LPFS) (13.5 vs. 15.4 months), or distant metastasis-free survival (DMFS) (11.7 vs 16.3 months) after surgery. After SBRT, 1-year OS was 77.0% and 2-year OS was 50.4%. Perioperative Claven-Dindo grade 3 or greater morbidity did not differ significantly between the nCT and nCT-SBRT cohorts (p = 0.81).

CONCLUSIONS

Despite having more advanced disease, the nCT-SBRT cohort was still more likely to undergo an R0 resection and experienced similar survival outcomes compared with the nCT alone cohort.

High local failure rates despite high margin-negative resection rates in a cohort of borderline resectable and locally advanced pancreatic cancer patients treated with stereotactic body radiation therapy following multi-agent chemotherapy

BACKGROUND

Stereotactic body radiation therapy (SBRT) for patients with borderline resectable and locally advanced pancreatic adenocarcinoma (BRPC/LAPC) remains controversial. Herein, we report on surgical, pathologic, and survival outcomes in BRPC/LAPC patients treated at a high-volume institution with induction chemotherapy (CTX) followed by 5-fraction SBRT.

METHODS

BRPC/LAPC patients treated between 2016 and 2019 were retrospectively reviewed. Surgical and pathological outcomes were descriptively characterized. Overall survival (OS) and progression-free survival (PFS) were analyzed using Cox proportional hazard regression. Locoregional failure and distant failure were analyzed with Fine-Gray competing risk model.

RESULTS

Of 155 patients, 91 (59%) had LAPC and 64 (41%) had BRPC. Almost all were treated with induction multi-agent CTX with either FOLFIRINOX (75%) or gemcitabine and nab-paclitaxel (24%) for a median duration of 4.0 months (1-18 months). All received SBRT to a median dose of 33 Gy. Among 64 BRPC patients, 50 (78%) underwent resection, of whom 48 (96%) achieved margin-negative (R0) resection. Among 91 LAPC patients, 57 (63%) underwent resection, of whom 50 (88%) achieved R0 resection. Despite the high R0 rate, 33% of patients experienced locoregional failure, which was a component of 44% of all failures. After SBRT, median OS and PFS were 18.7 and 7.7 months, respectively. After SBRT, 1- and 2-year OS probabilities were 70% and 45%, whereas, from diagnosis, they were 93% and 51%.

CONCLUSIONS

Although a high proportion of BRPC/LAPC patients treated with induction multi-agent CTX followed by SBRT successfully achieved R0 resection, locoregional failure remained common, highlighting the need to continue to optimize radiation delivery in this context.

In Pancreatic Adenocarcinoma Alpha-Synuclein Increases and Marks Peri-Neural Infiltration

α-Synuclein (α-syn) is a protein involved in neuronal degeneration. However, the family of synucleins has recently been demonstrated to be involved in the mechanisms of oncogenesis by selectively accelerating cellular processes leading to cancer. Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal human cancers, with a specifically high neurotropism. The molecular bases of this biological behavior are currently poorly understood. Here, α-synuclein was analyzed concerning the protein expression in PDAC and the potential association with PDAC neurotropism. Tumor (PDAC) and extra-tumor (extra-PDAC) samples from 20 patients affected by PDAC following pancreatic resections were collected at the General Surgery Unit, University of Pisa. All patients were affected by moderately or poorly differentiated PDAC. The amount of α-syn was compared between tumor and extra-tumor specimen (sampled from non-affected neighboring pancreatic areas) by using in situ immuno-staining with peroxidase anti-α-syn immunohistochemistry, α-syn detection by using Western blotting, and electron microscopy by using α-syn-conjugated immuno-gold particles. All the methods consistently indicate that each PDAC sample possesses a higher amount of α-syn compared with extra-PDAC tissue. Moreover, the expression of α-syn was much higher in those PDAC samples from tumors with perineural infiltration compared with tumors without perineural infiltration.

A novel method for predicting perineural invasion of distal cholangiocarcinoma on multidetector-row computed tomography

PURPOSE

Excessive perineural invasion (PNI) is associated with a high risk of radial margin (RM) positivity and a poor prognosis for patients with distal cholangiocarcinoma (DCC). This study evaluates a new method of predicting the extent of PNI preoperatively.

METHODS

The subjects of this retrospective study were 201 patients who underwent resection for DCC between 2002 and 2018. This study identified the 'periductal enation sign' (PES), defined as the surrounding soft tissue enhancement that appears as an enation from the circumference of the enhanced extrahepatic bile duct on multidetector-row computed tomography (MDCT) scans, as a predictor of PNI. We analyzed the outcomes of the patients in relation to the presence or absence of the PES on MDCT scans.

RESULTS

The PES in the PNI-positive group was significantly longer than that in the PNI-negative group. As the length of the PES extended, the grade of PNI increased. A positive PES was defined as a PES length of ≥ 2.0 mm. Patients with a positive PES were more frequently positive for RM (23.7% vs. 2.1%) and locoregional recurrence (23.7% vs. 6.3%) and exhibited significantly poorer overall survival than those with a negative PES (30.2% vs. 54.6% at 5 years).

CONCLUSIONS

The presence and extent of PNI can be predicted easily and effectively by the PES length. A positive PES was associated with poor local controllability and a poor prognosis.

Reconsideration of the Appropriate Dissection Range Based on Japanese Anatomical Classification for Resectable Pancreatic Head Cancer in the Era of Multimodal Treatment

Patients with resectable pancreatic cancer are considered to already have micro-distant metastasis, because most of the recurrence patterns postoperatively are distant metastases. Multimodal treatment dramatically improves prognosis; thus, micro-distant metastasis is considered to be controlled by chemotherapy. The survival benefit of "regional lymph node dissection" for pancreatic head cancer remains unclear. We reviewed the literature that could be helpful in determining the appropriate resection range. Regional lymph nodes with no suspected metastases on preoperative imaging may become areas treated with preoperative and postoperative adjuvant chemotherapy. Many studies have reported that the R0 resection rate is associated with prognosis. Thus, "dissection to achieve R0 resection" is required. The recent development of high-quality computed tomography has made it possible to evaluate the extent of cancer infiltration. Therefore, it is possible to simulate the dissection range to achieve R0 resection preoperatively. However, it is often difficult to distinguish between areas of inflammatory changes and cancer infiltration during resection. Even if the "dissection to achieve R0 resection" range is simulated based on the computed tomography evaluation, it is difficult to identify the range intraoperatively. It is necessary to be aware of anatomical landmarks to determine the appropriate dissection range during surgery.

Preoperative CT-based detection of extrapancreatic perineural invasion in pancreatic cancer

Accuracy for computed tomography (CT) diagnosis of extrapancreatic perineural invasion (EPNI) in pancreatic ductal adenocarcinoma (PDAC), which is a significant cause of recurrence, has not been established. The aim of the study was to evaluate the diagnostic accuracy of CT in detecting EPNI preoperatively in resectable PDAC of the pancreatic head. Retrospective study design was approved by institutional review board. Preoperative CT-series of 46 patients with resectable PDAC were evaluated by two independent observers. Plexus Pancreaticus Capitalis-II (PPC-II) was assessed as this area is more susceptible for EPNI. All patients underwent surgery with dedicated histopathology, which served as the reference standard. Histologically EPNI was confirmed in 63.1%. Sensitivity of MDCT was 93.1% (95% confidence interval (CI) 77.23% to 99.15%), specificity 64.7% (95% CI 38.33% to 85.79%) with area under the curve (AUC) 0.789 for the first observer. Positive predictive value (PPV) was 81.82% (95% CI 70.12% to 89.62%), negative predictive value (NPV-84.62% (95% CI 57.98% to 95.64%) with diagnostic accuracy of 82.61% (95% CI 68.58% to 92.18%). Interobserver agreement showed k-value of 0.893 ([Formula: see text]), which represents very good agreement between observers. Median actual survival in patients without EPNI was 30 months (95% CI 18.284-41.716), in patients with EPNI-13 months (95% CI 12.115-13.885). CT provides sufficient diagnostic information to detect PPC-II invasion in patients with resectable PDAC of the pancreatic head. Preoperative detection of EPNI might be an additional argument to perform neoadjuvant chemotherapy in patients with resectable PDAC. It should be included in preoperative evaluation form of CT-findings.

Extrapancreatic Nerve Plexus Invasion on Imaging Predicts Poor Survival After Upfront Surgery for Anatomically Resectable Pancreatic Cancer

OBJECTIVES

This study aimed to analyze the risk factors for poor survival of the patients with anatomically resectable pancreatic ductal adenocarcinoma (PDAC), focusing on detailed computed tomography (CT) findings of tumor extent to the peripancreatic tissue.

METHODS

The study included 192 patients who underwent upfront pancreaticoduodenectomy for anatomically resectable PDAC. Preoperative CT images were rereviewed by an experienced radiologist for the pattern of tumor extension to the surrounding tissue: biliary, duodenal, serosal, retroperitoneal, portal venous, arterial, extrapancreatic nerve plexus, and other-organ invasion. Imaging findings and other clinical data that could be obtained before surgery were evaluated for their association with a shorter disease-specific survival (DSS) and recurrence-free survival (RFS).

RESULTS

Of the 192 anatomically resectable PDAC patients, extrapancreatic nerve plexus invasion was observed on CT in 38 patients (20%), and this finding was independently associated with a shorter DSS (hazard ratio, 2.258; P < 0.001) and RFS (hazard ratio, 2.665; P < 0.001). The median survival of patients with and without extrapancreatic nerve plexus invasion on CT was 19.7 versus 38.5 months (P < 0.001).

CONCLUSIONS

Extrapancreatic nerve plexus invasion was shown as an only CT finding associated with a shorter DSS and RFS after upfront surgery for the patients with anatomically resectable PDAC.

Preliminary study of perineural invasion in patients with hilar cholangiocarcinoma by computed tomography imaging

OBJECTIVES

To explore the characteristics of hepatic plexuses and celiac ganglia, and their relationships with hilar cholangiocarcinoma (HCCA) perineural invasion (PNI) by computed tomography (CT) imaging preliminarily.

MATERIALS AND METHODS

Sixty-five HCCA patients (55 with PNI) between December 2014 and February 2019 were included in this retrospective study. The CT values of hepatic plexuses in Region 1 (the fat tissue around proper hepatic artery), in Region 2 (the fat tissue around common hepatic artery), and in Region 3 (the fat tissue around celiac trunk), and the CT values and diameters of celiac ganglia were measured on the preoperative CT images. Mann-Whitney U test was used to compare the measurements between PNI group and Non-PNI group. ROC curve was performed to analyze the sensitivity, specificity and optimal threshold of the measurements in discriminating HCCA PNI.

RESULTS

The CT values of hepatic plexuses in PNI group were significantly higher than those in Non-PNI group (all P < 0.05). The CT values of right celiac ganglia were significantly higher in PNI group than those in Non-PNI group (P = 0.007). There were no significant differences between two groups in other measurements (all P > 0.05). The CT values of hepatic plexuses in Region 1 showed the highest sensitivity (90.9%) and the CT values of right celiac ganglia demonstrated the highest specificity (80.0%).

CONCLUSIONS

The increases of CT values of hepatic plexuses around proper hepatic artery may be used as an indicator of PNI in patients with HCCA and may facilitate treatment planning in considering its early recurrence after surgery and poor prognosis.

Reticular pattern around superior mesenteric artery in computed tomography imaging predicting poor prognosis of pancreatic head cancer

BACKGROUND

Some patients with pancreatic ductal adenocarcinoma (PDAC) demonstrate a reticular pattern around the superior mesenteric artery (SMA) in computed tomography scans. This study aimed to clarify the clinical significance of the reticular pattern in pancreatic head cancer.

METHODS

A total of 91 patients with pancreatic head cancer, who underwent upfront pancreaticoduodenectomy between 2004 and 2017, were included. Patients without reticular pattern (Non-group, n = 39); with reticular pattern around SMA (Ret-group, n = 39); and with soft tissue contact (Soft-group, n = 13) were compared.

RESULTS

Median overall survival (OS) of patients in the Ret-group was significantly worse than that in the Non-group (21.3 vs. 57.0 months; P < 0.001) and equivalent to that in the Soft-group. In the multivariate analysis, reticular pattern and high CA19-9 levels were identified as independent predictors of OS. Microscopically, only fibrotic thickenings were identified corresponding to the reticular pattern areas, and no difference in the frequency of early local recurrence was noted between the Non and Ret-groups. Lymphovascular invasion was significantly different between the two groups; furthermore, early distant recurrence was more frequent in the Ret-group.

CONCLUSIONS

The reticular pattern around SMA is an important prognostic factor related to frequent distant recurrence in patients with pancreatic cancer.

Extrapancreatic perineural invasion in pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma continues to be a highly lethal disease, despite advances in modern medicine. Curative surgical options continue to carry significant morbidity and offer little improvement in overall 5-year survival. Currently, imaging plays an essential role in the pre-operative evaluation of patients who are undergoing evaluation for resection. However, some pancreatic cancers have particularly aggressive biology, despite appearing resectable by conventional imaging criteria. Imaging biomarkers that serve as surrogates for tumors with such aggressive phenotype have been recently described, namely duodenal invasion and extrapancreatic perineural invasion. In this pictorial review, we will summarize key concepts of extrapancreatic perineural invasion, describe its association with a poor prognosis, and highlight the role of imaging in its detection.

Staging pancreatic carcinoma by computed tomography

Pancreatic carcinoma is becoming more common in our environment; the mortality rate for this tumor has barely changed over the last 20 years. Early diagnosis and accurate staging are crucial to ensure an appropriate therapeutic approach, which should aim to improve survival in patients in whom complete resection is possible and to minimize surgical morbidity and mortality in those with a high risk of residual disease after the intervention. Various imaging techniques are used for tumor staging: multidetector computed tomography (CT), magnetic resonance imaging, positron emission tomography (PET)-CT, endoscopic ultrasound, and diagnostic laparoscopy. Currently, multidetector CT is the technique of choice for the study of pancreatic tumors; thus, this article aims to review the state of the art in staging adenocarcinoma of the pancreas, focusing mainly on the applications and limitations of this technique.

Borderline resectable pancreatic cancer

Surgery followed by adjuvant chemotherapy remains the only treatment option for pancreatic ductal adenocarcinoma (PDAC) with the chance of long-term survival. If a radical tumor resection is possible, 5-year survival rates of 20-25% can be achieved. Pancreatic surgery has significantly changed during the past years and resection approaches have been extended beyond standard procedures, including vascular and multivisceral resections. Consequently, borderline resectable pancreatic ductal adenocarcinoma (BR-PDAC), which has recently been defined by the International Study Group for Pancreatic Surgery (ISGPS), has become a controversial issue with regard to its management in terms of upfront resection vs. neoadjuvant treatment and sequential resection. Preoperative diagnostic accuracy to define resectability of PDAC is a keypoint in this context as well as the surgical and interdisciplinary expertise to perform advanced pancreatic surgery and manage complications. The present mini-review summarizes the current state of definition, management and outcome of BR-PDAC. Furthermore, the topic of ongoing and future studies on neoadjuvant treatment which is closely related to borderline resectability in PDAC is discussed.

Perineural invasion in prostate biopsy specimens is associated with increased bone metastasis in prostate cancer

BACKGROUND

We aimed to evaluate the relationship between perineural invasion (PNI) and bone metastasis in prostate cancer (PCa).

METHODS

We retrospectively reviewed the data of 633 PCas who had whole-body bone scan (WBBS) between 2008 and 2014. We recorded the age, clinical T-stage, total PSA (tPSA) prior to biopsy, Gleason sum (GS), and PNI in transrectal ultrasound guided biopsy (TRUS-Bx) and digital rectal examination findings. Bone metastases were assessed with WBBS and magnetic resonance image if WBBS was suspicious. We divided the patients into two groups according to NCCN criteria: (Group 1) bone scan not indicated, (Group 2) bone scan indicated.

RESULTS

There were 262 patients in Group 1 and 371 in 2. There is not significant relationship between PNI and bone metastasis in Group 1. However, there is very limited number of metastatic patients (n = 12) in this group. There is a strong relationship between PNI and bone metastasis in Group 2 (P = 0.001). Sensitivity, specificity and positive predictive value of PNI for bone metastasis were 72.4%, 81.7%, and 77.7%, respectively. In this group, tPSA, GS, positive DRE, and PNI were significant covariates for prediction of bone metastasis in univariate and multivariate analysis (except age). The most powerful predictor was PNI, and it increased the risk of bone metastasis 11-fold.

CONCLUSIONS

PNI in the TRUS-Bx specimens is the most powerful predictive histopathological feature for bone metastasis, by increasing the risk of bone metastasis 11-fold in NCCN bone scan indicated patients (Group 2).

Three-dimensional volume-rendered multidetector CT imaging of the posterior inferior pancreaticoduodenal artery: its anatomy and role in diagnosing extrapancreatic perineural invasion

Extrapancreatic perineural spread in pancreatic adenocarcinoma contributes to poor outcomes, as it is known to be a major contributor to positive surgical margins and disease recurrence. However, current staging classifications have not yet taken extrapancreatic perineural spread into account. Four pathways of extrapancreatic perineural spread have been described that conveniently follow small defined arterial pathways. Small field of view three-dimensional (3D) volume-rendered multidetector computed tomography (MDCT) images allow visualization of small peripancreatic vessels and thus perineural invasion that may be associated with them. One such vessel, the posterior inferior pancreaticoduodenal artery (PIPDA), serves as a surrogate for extrapancreatic perineural spread by pancreatic adenocarcinoma arising in the uncinate process. This pictorial review presents the normal and variant anatomy of the PIPDA with 3D volume-rendered MDCT imaging, and emphasizes its role as a vascular landmark for the diagnosis of extrapancreatic perineural invasion from uncinate adenocarcinomas. Familiarity with the anatomy of PIPDA will allow accurate detection of extrapancreatic perineural spread by pancreatic adenocarcinoma involving the uncinate process, and may potentially have important staging implications as neoadjuvant therapy improves.

Diagnostic performance of MDCT for predicting important prognostic factors in pancreatic cancer

OBJECTIVES

Tumor stage, node metastasis, tumor size, vascular invasion, and perineural invasion are the most important prognostic factors that might be determined by preoperative multidetector computed tomography (MDCT) in pancreatic cancer. The purpose of our study is to investigate diagnostic accuracy of MDCT for determining these prognostic factors.

METHODS

For 6 years, 111 patients with surgically resected pancreatic cancer underwent preoperative MDCT. Two radiologists retrospectively assessed tumor stage, node metastasis, tumor size, and vascular invasion. They also graded perineural invasion using a 3-point scale focused on 5 routes. Statistical analyses were performed using the receiver operating characteristic analysis, McNemar test, and paired t test.

RESULTS

Statistically, tumor size on specimens (3.4 ± 1.46 cm) is larger than tumor size on MDCT (3.2 ± 1.41 cm; P = 0.001). The diagnostic accuracy rates for tumor stage were 82.9% and 77.5%, with moderate agreement (κ = 0.732). The accuracy rates for node metastasis were 59.5% and 55.0%, with fair agreement (κ = 0.597). The diagnostic accuracy rates for vascular invasion were 94% and 92%. The areas under the curve for perineural invasion were 0.733 and 0.66 (P = 0.069), with moderate agreement (κ = 0.77).

CONCLUSIONS

Multidetector computed tomography is very useful for the preoperative evaluation of tumor stage, perineural invasion, and vascular invasion of pancreatic cancer, but it has limited evaluation of node metastasis and tumor size.

"Peripancreatic strands appearance" in pancreatic body and tail carcinoma: evaluation by multi-detector CT with pathological correlation

OBJECTIVES

In pancreatic body and tail carcinoma, "peripancreatic strands appearance" is frequently seen on multidetector CT (MDCT). The purpose of this study was to clarify the pathological and clinical implications of peripancreatic strands appearance.

METHODS

We retrospectively evaluated MDCT images in 17 patients with pancreatic body and tail carcinoma who underwent surgical resection. Peripancreatic strands appearance was defined as the strands structure deriving from the primary lesion and associated with increased CT attenuation of surrounding adipose tissues. All CT examinations were performed by contrast-enhanced MDCT with a multiplanar reformation technique.

RESULTS

Peripancreatic strands appearance was detected on MDCT in 13 (76%) patients. The maximum width of the peripancreatic strands seen on MDCT was 1.55 ± 0.36 mm (range, 1.0-2.5 mm). This CT finding was well correlated with extrapancreatic carcinoma invasion with marked fibrotic thickening of adipose tissue septa, including microvessels. This pathological finding was confirmed in all 13 patients with positive CT finding whereas it was not confirmed in the 4 patients with negative CT finding.

CONCLUSION

Peripancreatic strands appearance on MDCT in pancreatic body and tail carcinoma reflects extrapancreatic carcinoma invasion with marked fibrotic thickening of adipose tissue septa. This CT finding would indicate the property of carcinoma aggressiveness.

Extrahepatic bile duct cancer: invasion of the posterior hepatic plexuses--evaluation using multidetector CT

PURPOSE

To assess the utility of axial and coronal reformatted multidetector computed tomographic (CT) images in the evaluation of the invasion of posterior hepatic plexuses by extrahepatic bile duct cancer.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board, and informed consent was waived. Forty-three patients (22 men, 21 women; age range, 40-80 years; mean age, 65 years) with surgically resected cancer involving the extrahepatic bile duct between December 2004 and September 2010 were included. Posterior hepatic plexus 1 runs from the superior and middle bile duct to the right celiac ganglion, and posterior hepatic plexus 2 runs between the lower bile duct and right celiac ganglion behind the portal vein. Invasion of the posterior hepatic plexuses was elucidated by using pathologic and postoperative multidetector CT findings. Three radiologists independently evaluated the preoperative axial and coronal reformatted images with a separate viewing session for the invasion of posterior hepatic plexuses that was detected on the basis of the presence of increased attenuation of fat tissue along the nerve routes. Receiver operating characteristic analysis was performed to compare the diagnostic performance of the two image interpretations.

RESULTS

Invasion of posterior hepatic plexus 1 and of posterior hepatic plexus 2 was recognized in 10 (23%) and nine (21%) of 43 patients, respectively. The diagnostic performance of coronal reformatted image interpretation was significantly greater than that for axial image interpretation (mean area under the curve, 0.99 vs 0.89, P = .04; mean accuracy, 95% vs 82%, P = .003). In all reviewers, one false-positive diagnosis of the invasion of posterior hepatic plexus occurred on axial and/or coronal image display types because of fibrosis and inflammatory cell infiltration along these plexus routes.

CONCLUSION

Coronal reformatted images can be useful for accurate diagnosis of the invasion of posterior hepatic plexuses and may facilitate surgical decision making in regard to the resection of celiac ganglion.

CT and MR imaging patterns for pancreatic carcinoma invading the extrapancreatic neural plexus (Part I): Anatomy, imaging of the extrapancreatic nerve

Pancreatic carcinoma is an extremely high-grade malignant tumor with fast development and high mortality. The incidence of pancreatic carcinoma continues to increase. Peripancreatic invasion and metastasis are the main characteristics and important prognostic factors in pancreatic carcinoma, especially invasion into the nervous system; pancreatic nerve innervation includes the intrapancreatic and extrapancreatic nerves. A strong grasp of pancreatic nerve innervation may contribute to our understanding of pancreatic pain modalities and the metastatic routes for pancreatic carcinomas. Computed tomography (CT) and magnetic resonance imaging (MRI) are helpful techniques for depicting the anatomy of extrapancreatic nerve innervation. The purpose of the present work is to show and describe the anatomy of the extrapancreatic neural plexus and to elucidate its characteristics using CT and MRI, drawing on our own previous work and the research findings of others.

CT and MR imaging patterns for pancreatic carcinoma invading the extrapancreatic neural plexus (Part II): Imaging of pancreatic carcinoma nerve invasion

Computed tomography (CT) and magnetic resonance imaging (MRI) are excellent modalities which have the ability to detect, depict and stage the nerve invasion associated with pancreatic carcinoma. The aim of this article is to review the CT and MR patterns of pancreatic carcinoma invading the extrapancreatic neural plexus and thus provide useful information which could help the choice of treatment methods. Pancreatic carcinoma is a common malignant neoplasm with a high mortality rate. There are many factors influencing the prognosis and treatment options for those patients suffering from pancreatic carcinoma, such as lymphatic metastasis, adjacent organs or tissue invasion, etc. Among these factors, extrapancreatic neural plexus invasion is recognized as an important factor when considering the management of the patients.

One hundred and seventy-eight consecutive pancreatoduodenectomies without mortality: role of the multidisciplinary approach

BACKGROUND

Pancreatoduodenectomy offers the only chance of cure for patients with periampullary cancers. This, however, is a major undertaking in most patients and is associated with a significant morbidity and mortality. A multidisciplinary approach to the workup and follow-up of patients undergoing pancreatoduodenectomy was initiated at our institution to improve the diagnosis, resection rate, mortality and morbidity. We undertook the study to assess the effect of this approach on diagnosis, resection rates and short-term outcomes such as morbidity and mortality.

METHODS

A prospective database of patients presenting with periampullary cancers to a single surgeon between April 2004 and April 2010 was reviewed. All cases were discussed at a multidisciplinary meeting comprising surgeons, gastroenterologists, radiologists, oncologists, radiation oncologists, pathologists and nursing staff. A standardized investigation and management algorithm was followed. Complications were graded according to the Clavien-Dindo classification.

RESULTS

A total of 295 patients with a periampullary lesion were discussed and 178 underwent pancreatoduodenectomy (resection rate 60%). Sixty-one patients (34%) required either a vascular or an additional organ resection. Eighty-nine patients experienced complications, of which the commonest was blood transfusion (12%). Thirty-four patients (19%) had major complications, i.e. grade 3 or above. There was no in-hospital, 30-day or 60-day mortality.

CONCLUSIONS

Pancreatoduodenectomy can safely be performed in high-volume centers with very low mortality. The surgeon's role should be careful patient selection, intensive preoperative investigations, use of a team approach, and an unbiased discussion at a multidisciplinary meeting to optimize the outcome in these patients.

Pathways of extrapancreatic perineural invasion by pancreatic adenocarcinoma: evaluation with 3D volume-rendered MDCT imaging

OBJECTIVE

The purpose of this article is to familiarize radiologists with the common pathways of extrapancreatic perineural invasion of pancreatic adenocarcinoma and to highlight the potential value of 3D volume-rendered MDCT in its diagnosis.

CONCLUSION

The perineural plexuses closely follow peripancreatic vessels, which are well depicted by contrast-enhanced 3D volume-rendered imaging, thus facilitating the diagnosis of extrapancreatic perineural invasion of pancreatic adenocarcinoma.

Extrapancreatic neural plexus invasion by pancreatic carcinoma: characteristics on magnetic resonance imaging

BACKGROUND

Our objective is to study the characteristics of extrapancreatic neural plexus invasion by pancreatic carcinoma on MR imaging.

METHODS

20 patients with both pancreatic carcinoma and extrapancreatic neural plexus invasion confirmed by pathology were recruited in this study. MR imaging was performed within 1 month before surgery. On MR images, signal intensity at the site of potential extrapancreatic neural plexus invasion, lymph nodes and tumor size were noted. The relationship of extrapancreatic neural plexus invasion to these findings was analyzed.

RESULTS

Signs of extrapancreatic neural plexus invasion were depicted on MR imaging in 80% of patients, which included streaky and strand-like signal intensity structure in fat tissue in 50% of patients and irregular masses adjacent to tumor in 30%. Signal intensity at invasion site was similar to that of pancreatic carcinoma. The frequencies of patients with vascular invasion and with lymph nodes larger than 5 mm were, respectively, 50% and 55%. Tumor diameter was 24 +/- 7 mm on MR imaging. Extrapancreatic neural plexus invasion was correlated with vascular invasion (r = 0.58, P < 0.005), slightly related with lymphadenopathy (r = 0.35, 0.1 > P > 0.05), but not related with tumor size.

CONCLUSION

MR imaging is useful to depict extrapancreatic neural plexus invasion by pancreatic carcinoma.

[Computerized tomography in postoperative monitoring of patients with the Whipple operation--characteristics of CT findings]

We presented the postoperative CT findings of patients after the Whipple's operation (cephalic pancreaticoduodenectomy), performed for the pancreatic head cancer, or ampullary carcinoma. Technique of the Whipple's operation is described, and normal and pathological postoperative CT findings, which are characteristic for the immediate (early) and delayed (late) follow-up period, are presented. In addition, difficulties in differentiation of afferent jejunal loop from the recurrent tumor by CT are discussed, and references from the literature about the possibilities of successful visualization of the afferent jejunal loop are cited. Possible locations and CT appearances of the tumor recurrences are presented. An overview of the literature is provided.

New insight of pancreatic imaging: from "unexplored" to "explored"

Pancreatic cancer remains one of the most difficult neoplasms for early diagnosis and treatment. Recent advances of imaging including 3D volume data setting in multidetector-row CT (MDCT) and MRI are urging us to focus on the imaging of normal and pathological conditions of pancreatic parenchyme and peripancreatic structures, which are frequently involved by pancreatic cancers and are affecting the prognosis of patients with pancreatic cancers. In this Feature Section, five main topics of pancreatic imaging are addressed: pancreatic arterial territories, imaging of the intra- and peripancreatic venous anatomy and its clinical significance, imaging of the peripancreatic lymphatic network and its clinical significance for staging of pancreatic cancer, perfusion characteristics of pancreatic cancer to differentiate chronic mass-forming pancreatitis, and development of intraductal papillary mucinus neoplasms of the pancreas (IPMNs) to adenocarcinoma and pancreatic invasion. Recognition and understanding of the imaging anatomy of the pancreas might lead to precise staging of pancreatic cancer and to new approaches of less-invasive treatment. Follow-up of patients with IPMNs of the pancreas on imaging seems, at this time, to be the most valuable strategy in the high-risk group selection.