Follow-up After Surgery for Pancreatic Ductal Adenocarcinoma: Steps Toward an International Consensus

The diagnostic performance of CT versus FDG PET-CT for the detection of recurrent pancreatic cancer: a systematic review and meta-analysis

OBJECTIVES

Radiologic surveillance after resection of pancreatic ductal adenocarcinoma (PDAC) can provide information on the extent and location of disease recurrence. This systematic review and meta-analysis aims to give an overview of the literature on the diagnostic performance of different imaging modalities for the detection of recurrent disease after surgery for PDAC.

METHODS

A systematic search was performed in PubMed, EMBASE and Cochrane Library up to 20 December 2017. All studies reporting on the diagnostic value of imaging modalities for the detection of local and/or distant disease recurrence during follow-up after resection of PDAC were eligible. Both histologic confirmation of recurrent PDAC and clinical confirmation by disease progression on follow-up imaging were considered as suitable reference standard. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool was used for critical appraisal of methodological quality. Diagnostic accuracy data were extracted or calculated and presented in forest plots. A bivariate random-effects model was used to calculate pooled estimates of sensitivity and specificity.

RESULTS

A total of seven retrospective studies with 333 relevant patients were ultimately eligible for data extraction. Overall, the methodological quality of the included studies was acceptable. All seven articles described test results of contrast-enhanced CT, whilst five and three articles reported outcomes on diagnostic accuracy of FDG PET-CT and FDG PET-CT combined with contrast-enhanced CT, respectively. For CT, pooled estimates for sensitivity were 0.70 (95% CI 0.61-0.78) and for specificity 0.80 (95% CI 0.69-0.88). For FDG PET-CT, pooled estimates for sensitivity and specificity were 0.88 (95% CI 0.81-0.93) and 0.89 (95% CI 0.80-0.94), respectively. For FDG PET-CT in combination with contrast-enhanced CT, pooled estimates for sensitivity were 0.95 (95% CI 0.88-0.98) and for specificity 0.81 (95% CI 0.63-0.92).

CONCLUSIONS

According to the current literature, post-operative CT has a moderate diagnostic accuracy in the detection of recurrent disease. FDG PET-CT imaging could be of additional value when disease recurrence is suspected despite negative or equivocal CT findings. Nevertheless, evidence supporting radiologic surveillance after resection of PDAC is limited. Future prospective studies are needed to optimize surveillance strategies after resection of pancreatic cancer.

Use of imaging during symptomatic follow-up after resection of pancreatic ductal adenocarcinoma

BACKGROUND

Controversy exists whether follow-up after resection of pancreatic ductal adenocarcinoma (PDAC) should include standardized imaging for the detection of disease recurrence. The purpose of this study was to evaluate how often patients undergo imaging in a setting where routine imaging is not performed. Secondly, the pattern, timing, and treatment of recurrent PDAC were assessed.

MATERIALS AND METHODS

This was a post hoc analysis of a prospective database of all consecutive patients undergoing pancreatic resection of PDAC between January 2011 and January 2015. Data on imaging procedures during follow-up, recurrence location, and treatment for recurrence were extracted and analyzed. Associations between clinical characteristics and post-recurrence survival were assessed with the log-rank test and Cox univariable and multivariable proportional hazards models.

RESULTS

A total of 85 patients were included. Seventy-four patients (87%) underwent imaging procedures during follow-up at least once, with a mean amount of 3.1 ± 1.9 imaging procedures during the entire follow-up period. Sixty-eight patients (80%) were diagnosed with recurrence, 58 (85%) of whom after the manifestation of clinical symptoms. Additional tumor-specific treatment was administered in 17 of 68 patients (25%) with recurrence. Patients with isolated local recurrence, treatment after recurrence, and a recurrence-free survival >10 mo had longer post-recurrence survival.

CONCLUSIONS

Even though a symptomatic follow-up strategy does not include routine imaging, the majority of patients with resected PDAC underwent additional imaging procedures during their follow-up period. Further prospective studies are needed to determine the actual clinical value, psychosocial implications, and cost-effectiveness of different forms of follow-up after resection of PDAC.