Morphological analysis of pancreatic adenocarcinoma on multidetector row computed tomography: implications for treatment response evaluation

Neoadjuvant treatment of pancreatic ductal adenocarcinoma: Whom, when and how

Pancreatic ductal adenocarcinoma (PDAC), which is notorious for its aggressiveness and poor prognosis, remains an area of great unmet medical need, with a 5-year survival rate of 10% - the lowest of all solid tumours. At diagnosis, only 20% of patients have resectable pancreatic cancer (RPC) or borderline RPC (BRPC) disease, while 80% of patients have unresectable tumours that are locally advanced pancreatic cancer (LAPC) or have distant metastases. Nearly 60% of patients who undergo upfront surgery for RPC are unable to receive adequate adjuvant chemotherapy (CHT) because of postoperative complications and early cancer recurrence. An important paradigm shift to achieve better outcomes has been the sequence of therapy, with neoadjuvant CHT preceding surgery. Three surgical stages have emerged for the preoperative assessment of nonmetastatic pancreatic cancers: RPC, BRPC, and LAPC. The main goal of neoadjuvant treatment (NAT) is to improve postoperative outcomes through enhanced selection of candidates for curative-intent surgery by identifying patients with aggressive or metastatic disease during initial CHT, reducing tumour volume before surgery to improve the rate of margin-negative resection (R0 resection, a microscopic margin-negative resection), reducing the rate of positive lymph node occurrence at surgery, providing early treatment of occult micrometastatic disease, and assessing tumour chemosensitivity and tolerance to treatment as potential surgical criteria. In this editorial, we summarize evidence concerning NAT of PDAC, providing insights into future practice and study design. Future research is needed to establish predictive biomarkers, measures of therapeutic response, and multidisciplinary strategies to improve patient-centered outcomes.

In Neoadjuvant FOLFIRINOX Chemotherapy for Pancreatic Ductal Adenocarcinoma, Which Response is the More Reliable Indicator for Prognosis, Radiologic or Biochemical?

BACKGROUND

In this era of increasing neoadjuvant chemotherapy, methods for evaluating responses to neoadjuvant chemotherapy are still diverse among institutions. Additionally, the efficacy of adjuvant chemotherapy for patients undergoing neoadjuvant chemotherapy remains unclear. Therefore, this retrospective study was performed to evaluate the effectiveness of methods for assessing response to neoadjuvant chemotherapy and the need for adjuvant chemotherapy in treating patients with non-metastatic pancreatic ductal adenocarcinoma.

METHODS

The study identified 150 patients who underwent neoadjuvant FOLFIRINOX chemotherapy followed by curative-intent pancreatectomy. The patients were stratified by biochemical response based on the normalization of carbohydrate antigen 19-9 and by radiologic response based on size change at imaging.

RESULTS

The patients were classified into the following three groups based on their response to neoadjuvant chemotherapy and prognosis: biochemical responders (BR+), radiology-only responders (BR-/RR+), and non-responders (BR-/RR-). The 3-year overall survival rate was higher for BR+ (71.0%) than for BR-/RR+ (53.6%) or BR-/RR- (33.1%) (P < 0.001). Response to neoadjuvant chemotherapy also was identified as a significant risk factor for recurrence in a comparison between BR-/RR+ and BR+ (hazard ratio [HR], 2.15; 95% confidence interval [CI] 1.19-3.88; P = 0.011) and BR-/RR- (HR, 3.82; 95% CI 2.41-6.08; P < 0.001). Additionally, regardless of the response to neoadjuvant chemotherapy, patients who completed adjuvant chemotherapy had a significantly higher 3-year overall survival rate than those who did not.

CONCLUSIONS

This response evaluation criterion for neoadjuvant chemotherapy is feasible and can significantly predict prognosis. Additionally, completion of adjuvant chemotherapy could be helpful to patients who undergo neoadjuvant chemotherapy regardless of their response to neoadjuvant chemotherapy.

Retrospective Evaluation of Treatment Response in Patients with Nonmetastatic Pancreatic Cancer Using CT and CA 19-9

Background Imaging studies have limitations in evaluating pancreatic ductal adenocarcinoma (PDAC) treatment response. Purpose To investigate the effectiveness of combined CT and carbohydrate antigen 19-9 (CA 19-9) evaluation at 8 weeks after first-line treatment to predict overall survival (OS) of patients with nonmetastatic PDAC. Materials and Methods Patients with nonmetastatic PDAC who received first-line treatment with either chemotherapy or concurrent chemoradiation in a single-center PDAC cohort registry were retrospectively enrolled in the study between January 2013 and December 2016. Follow-up CT images obtained 8 weeks after treatment were evaluated according to Response Evaluation Criteria in Solid Tumors. Patients with partial response (PR) or stable disease (SD) were defined as CT responders, and those with progressive disease (PD) were defined as CT nonresponders. Patients with a normalized CA 19-9 level at 8-week follow-up were defined as CA 19-9 responders, and those with a nonnormalized or nonelevated CA 19-9 level were defined as CA 19-9 nonresponders. OS was compared using the Kaplan-Meier method with Breslow analysis. Results A total of 197 patients (mean age ± standard deviation, 65 years ± 10; 107 men) were evaluated. Patients with PD (n = 17) showed shorter OS than those with SD (n = 147; P < .001) or PR (n = 33; P = .003). OS did not differ between the patients with PR and those with SD (P = .60). When the CT and CA 19-9 responses were integrated, OS was longest in CT and CA 19-9 responders (group 1, n = 27; median OS, 26.6 months [95% CI: 9.0, 44.1]), followed by CT responders but CA 19-9 nonresponders (group 2, n = 153; median OS, 15.9 months [95% CI: 13.3, 18.5]; P = .007 vs group 1) and CT and CA 19-9 nonresponders (group 3, n = 17; median OS, 6.5 months [95% CI: 0.8, 12.2]; P < .001 vs group 2). Conclusion Integrated evaluation with CT and carbohydrate antigen 19-9 response allowed more accurate stratification of survival in patients with pancreatic ductal adenocarcinoma in the early treatment period than did evaluation according to Response Evaluation Criteria in Solid Tumors. © RSNA, 2022 Online supplemental material is available for this article.

Tumor Size Differences Between Preoperative Endoscopic Ultrasound and Postoperative Pathology for Neoadjuvant-Treated Pancreatic Ductal Adenocarcinoma Predict Patient Outcome

BACKGROUND & AIMS

The assessment of therapeutic response after neoadjuvant treatment and pancreatectomy for pancreatic ductal adenocarcinoma (PDAC) has been an ongoing challenge. Several limitations have been encountered when employing current grading systems for residual tumor. Considering endoscopic ultrasound (EUS) represents a sensitive imaging technique for PDAC, differences in tumor size between preoperative EUS and postoperative pathology after neoadjuvant therapy were hypothesized to represent an improved marker of treatment response.

METHODS

For 340 treatment-naïve and 365 neoadjuvant-treated PDACs, EUS and pathologic findings were analyzed and correlated with patient overall survival (OS). A separate group of 200 neoadjuvant-treated PDACs served as a validation cohort for further analysis.

RESULTS

Among treatment-naïve PDACs, there was a moderate concordance between EUS imaging and postoperative pathology for tumor size (r = 0.726, P < .001) and AJCC 8^th edition T-stage (r = 0.586, P < .001). In the setting of neoadjuvant therapy, a decrease in T-stage correlated with improved 3-year OS rates (50% vs 31%, P < .001). Through recursive partitioning, a cutoff of ≥47% tumor size reduction was also found to be associated with improved OS (67% vs 32%, P < .001). Improved OS using a ≥47% threshold was validated using a separate cohort of neoadjuvant-treated PDACs (72% vs 36%, P < .001). By multivariate analysis, a reduction in tumor size by ≥47% was an independent prognostic factor for improved OS (P = .007).

CONCLUSIONS

The difference in tumor size between preoperative EUS imaging and postoperative pathology among neoadjuvant-treated PDAC patients is an important prognostic indicator and may guide subsequent chemotherapeutic management.

Tumor growth kinetics versus RECIST to assess response to locoregional therapy in breast cancer liver metastases

RATIONALE AND OBJECTIVES

The aim of our study was to evaluate changes in growth kinetics of breast cancer liver metastasis in response to locoregional therapy and compare them to Response Evaluation Criteria in Solid Tumors (RECIST).

MATERIALS AND METHODS

This Health Insurance Portability and Accountability Act-compliant retrospective study was Institutional Review Board approved. Thirty-four chemorefractory breast cancer liver metastases from 21 patients treated with yttrium-90 ((90)Y) were evaluated. Pre- and posttreatment computed tomography (CT) scans were used to calculate tumor growth kinetics. The growth parameter analyzed was reciprocal of doubling time (RDT). RDT range for stable disease (SD) was defined by the measurement error rate. A negative RDT below the SD range defined response and was categorized as either partial response (PR) or complete response, whereas a positive RDT value above the SD range indicated progressive disease (PD). Comparison was made to tumor response classification according to percentage change in the lesion's maximal diameter per RECIST. Lin's concordance correlation coefficient, Bland-Altman plot, Wilcoxon signed rank test, and Student t test were used for analysis. Significance was set at 0.05.

RESULTS

RDT range for SD ranged from -0.46 to +2.17. Six lesions with PR based on RECIST showed PR based on their volumetric growth rate (mean RDT of -17.3 ± 2.6). Similarly, one lesion with PD according to RECIST was categorized as PD based on its growth kinetics (RDT of 10.2). However, 14 (51.85%) lesions classified as SD by RECIST had PR according to growth kinetics (mean RDT of -7.8), six (22.22%) lesions were categorized as SD (mean RDT of 0.8), whereas seven (25.93%) lesions showed PD (mean RDT of 4.5). Growth kinetic parameters were significantly different for lesions with PR when compared to lesions with PD (P < .0001).

CONCLUSIONS

In patients with breast cancer liver metastases undergoing locoregional therapy, RECIST categorization may not be an accurate reflection of treatment response.

A radiologist's guide to treatment response criteria in oncologic imaging: anatomic imaging biomarkers

OBJECTIVE

The purpose of this article is to describe the imaging biomarkers of treatment response and provide an overview of anatomic imaging biomarkers.

CONCLUSION

Imaging biomarkers of treatment response have evolved into the primary endpoint of response in most phase 2 studies. Anatomic imaging biomarkers are applied to depict change in tumor size in response to treatment and are currently the most commonly applied method of treatment response evaluation.

Pancreatic carcinoma-specific immunotherapy using synthesised alpha-galactosyl epitope-activated immune responders: findings from a pilot study

BACKGROUND

Dendritic cell (DC)-based and cytokine-induced killer cell (CIK)-based therapy can induce specific antitumor T-cell responses. This clinical pilot study examined the safety, the feasibility, and the outcome of tumor-specific immunotherapy for patients with advanced pancreatic adenocarcinoma.

METHODS

Alpha-Gal epitopes were synthesised on pancreatic carcinoma cell membranes with α1,3-galactosyltransferase in vitro. Subsequently, the addition of natural human anti-Gal IgG to the processed membranes resulted in opsonization and effective phagocytosis by DCs, which were co-cultured with newly differentiated CIKs from bone marrow stem cells to generate tumor-specific immune responders ex vivo. Fourteen patients with inoperable stage III/IV pancreatic adenocarcinoma were enrolled in the study; the treatment procedure consisted of injections of DCs and CIKs.

RESULTS

Clinical observation showed that the procedure was safe and lacked serious side effects. Tests showed that 12 patients had strong positive delayed-type IV hypersensitivity to the autologous cancer cell lysate; robust systemic cytotoxicity elicited by interferon (IFN)γ expression by peripheral blood mononuclear cells; and significant increases in CD3+CD8+, CD3+CD45RO+, and CD3+CD56+ cells in peripheral blood lymphocytes after 3 injections. During the follow up, the percentages of CD3+CD8+, CD3+CD45RO+, and CD3+CD56+ cells returned to the normal range at 6 to 9 months after the third injection and IFNγ expression in the cells stayed at the higher level from the third injection to 24 months after the treatment.

CONCLUSIONS

This new tumor-specific immunotherapy is safe, feasible, and has great potential for pancreatic carcinoma treatment.

Comparison of response evaluation criteria in solid tumors with volumetric measurements for estimation of tumor burden in pancreatic adenocarcinoma and hepatocellular carcinoma

BACKGROUND

Response evaluation criteria in solid tumors (RECIST) is the accepted method for determining tumor progression. However, RECIST may not estimate disease burden accurately because the axial plane often does not produce the actual longest diameter. Volumetric measurements may be an alternative to better determine tumor size. Our aim was to compare volumetric measurements with RECIST in pancreatic ductal adenocarcinomas (PDA) and hepatocellular carcinomas (HCC).

METHODS

RECIST and volumetric measurements were determined in 9 patients with metastatic PDA and 17 patients with HCC who subsequently underwent liver transplantation. Gross pathologic measurements after hepatectomy also were analyzed for volumes.

RESULTS

Three-dimensional diameter in volumetric analysis was 38% and 36% higher than RECIST diameter in PDA and HCC, respectively (P < .01). However, RECIST yielded 78% and 23% larger estimated tumor volumes than volumetric analysis in PDA and HCC, respectively (P < .01). Gross pathologic volume in HCC showed a linear correlation with both volumetric analysis (r = .95; P < .01) and RECIST (r = .96; P < .01) but RECIST significantly overestimated gross pathologic volume by an average of 28% (P < .01) whereas volumetric analysis was similar to gross pathologic volume (P = .56). In categorizing treatment response in PDA, RECIST and volumetric analysis were in moderate agreement (κ = .49).

CONCLUSIONS

RECIST significantly may overestimate tumor burden compared with volumetric measurements in both PDA and HCC. Volumetric analysis may be the preferred method to detect tumor progression.

Response to treatment series: part 2, tumor response assessment--using new and conventional criteria

OBJECTIVE

Conventional anatomic imaging biomarkers, including World Health Organization (WHO) criteria and Response Evaluation Criteria in Solid Tumors (RECIST), although effective, have limitations. This article will discuss the conventional and newer morphologic imaging biomarkers for the assessment of tumor response to therapy.

CONCLUSION

Applying established methods of assessing tumor response to therapy allows consistency in image interpretation and facilitates communication with oncologists. Because of the new methods of treatment, assessment of necrosis and volumetric information will need to be incorporated into size-based criteria.

MDCT evaluation of the growth kinetics of serous and benign mucinous cystic neoplasms of the pancreas

We assessed the growth kinetics of pathologically proven benign neoplastic cystic lesions of the pancreas. The volume and longest axial diameter (LAD) of 20 pathologically proven pancreatic cystic lesions (12 mucinous cystic neoplasms (MCN) and 8 serous cystadenomas (SCN)) on 2 multidetector computed tomography scans, obtained before resection, were measured. Reciprocal of doubling time, doubling time and growth rate based on volume and LAD were calculated. A P value <0.05 was considered significant. For all cysts, growth kinetics based on volume were: reciprocal of doubling time (mean = 3.03, median=1.0), doubling time (mean = 644, median = 388 days) and growth rate (mean = 74.7, median = 5.7 ml/year). Results based on LAD were: reciprocal of doubling time (mean = 3.09, median = 1.3), doubling time (mean = 752, median = 273 days) and growth rate (mean = 24.5, median = 5.6 mm/year). These variables were not statistically different between MCNs and SCNs (P > 0.05 in all instances). Reciprocal of doubling time based on volume and LAD were comparable (P > 0.05). We concluded that the mean reciprocal of doubling time was 3.03 and 3.09 using volume and LAD, respectively. This may aid in designing follow-up guidelines for pancreatic cysts.

Imaging evaluation of therapeutic response in patients with pancreatic cancer: recent advances

Chemoradiotherapy is the primary choice of non-surgical treatment of advanced pancreatic cancer, and diagnostic imaging plays an important role in objectively assessing early therapeutic response. This article systematically reviews the criteria for evaluation of therapeutic response in solid tumors and their application in pancreatic cancer, highlighting some key contents in imaging evaluation of therapeutic response in patients with pancreatic cancer.

Splenic volume model constructed from standardized one-dimensional MDCT measurements

OBJECTIVE

The purposes of this study were to construct a model for estimation of splenic volume from standardized one-dimensional diameters of the spleen and to compare that model with the ellipsoid model for estimation of splenic volume.

MATERIALS AND METHODS

In this retrospective study, segmentation software was used for semiautomated quantification of splenic volume by counting CT voxels in 193 consecutively registered patients. For standardization of one-dimensional measurements, the software was used to measure transaxial diameter in the slice with the largest splenic cross-sectional area. By incorporation of splenic volume and the product of width, thickness, and length into the linear regression equation, a model for estimation of splenic volume was constructed, and its performance was externally assessed. Splenic volume also was calculated with the formula for a prolate ellipsoid. The ellipsoid volume and best-fit volumes were compared with segmented splenic volume by use of Bland-Altman plot and Lin concordance correlation. A value of p < 0.05 denoted statistical significance.

RESULTS

Splenic width was the best one-dimensional predictor of splenic volume (r = 0.84, p < 0.05). The linear regression fitted model for estimation of splenic volume (V(R)) in the initial 100 patients was V(R) = (0.36 × W × T × L) + 28, where W is width, T is thickness, and L is length (R(2) = 0.91, p < 0.05) and was externally validated by estimation of splenic volume in the other 93 patients. Compared with that observed with use of the ellipsoid formula, mean bias decreased from 22.57% to 0.93%, and the Lin coefficient increased from 0.81 to 0.96 with application of the best-fit model for calculation of splenic volume.

CONCLUSION

The best-fit model V(R) = (0.36 × W × T × L) + 28 is more optimized than the ellipsoid formula and is associated with less bias for estimation of splenic volume.

Unresectable locally advanced pancreatic cancer: a multimodal treatment using neoadjuvant chemoradiotherapy (gemcitabine plus stereotactic radiosurgery) and subsequent surgical exploration

BACKGROUND

Pancreatic cancer accounts for approximately 3% of cancer deaths in Europe. Locally advanced pancreatic cancer (LAPC) involves vascular structures, and resectability is low, with a median survival time of 6 to 11 months. We conducted a prospective, nonrandomized study of patients with LAPC to assess the effect of stereotactic body radiotherapy (SBRT) on local response, pain control, and quality of life (QOL).

METHODS

Twenty-three patients with histologically confirmed LAPC underwent SBRT. Radiotherapy (30 Gy) was delivered in three fractions, and treatment toxicity was assessed according to the Common Terminology Criteria for Adverse Events (CTCAE v. 3.0). All patients received also gemcitabine chemotherapy and were followed up until death. Local control was assessed according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria, pain control was assessed with a visual analog scale, and QOL was assessed with the SF-36 instrument (Italian v. 1.6).

RESULTS

No grade 2 or higher acute or late toxicity was observed. The overall local response ratio was 82.6% (14 partial response, 2 complete response, 3 stable disease). SBRT showed a good short-term efficacy in controlling both pain and QOL. Median survival was 10.6 months, with a median follow-up of 9 months. The LAPC became resectable in 8% of the patients. Median time to progression of disease was 7.3 months. Six patients developed early metastatic disease.

CONCLUSIONS

The SBRT method is a promising treatment for LAPC. Local control rates, even compared to historical data from conventional radiotherapy, can be achieved with minimal toxicity. Resectability can also be achieved.