Value of Pretreatment 18F-fluorodeoxyglucose Positron Emission Tomography in Patients With Localized Pancreatic Cancer Treated With Neoadjuvant Therapy

Abstract

Background: 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) imaging is not routine in patients with localized pancreatic cancer (PC). We evaluated the prognostic value of PET/CT in patients who received neoadjuvant therapy. Methods: Patients with localized PC underwent pretreatment PET/CT with or without posttreatment (preop) PET/CT. Maximum standardized uptake values (SUV) were classified as high or low based on a cut point of 7.5 at diagnosis (SUV dx) and 3.5 after neoadjuvant therapy (preoperative; SUV preop). Preop carbohydrate antigen 19-9 (CA19-9) was classified as normal (≤35 U/mL) or elevated. Results: Pretreatment PET/CT imaging was performed on 201 consecutive patients; SUV dx was high in 98 (49%) and low in 103 (51%). Preop PET/CT was available in 104 (52%) of the 201 patients; SUV preop was high in 60 (58%) and low in 44 (42%). Following neoadjuvant therapy, preop CA19-9 was normal in 90 (45%) patients and elevated in 111 (55%). Median overall survival (OS) of all patients was 27 months; 33 months for the 103 patients with a low SUV dx and 22 months for the 98 patients with a high SUV dx (p = 0.03). Median OS for patients with low SUV dx /normal preop CA19-9, high SUV dx /normal preop CA19-9, low SUV dx /elevated preop CA19-9, and high SUV dx /elevated preop CA19-9 were 66, 34, 23, and 17 months, respectively (p < 0.0001). OS was 44 months for the 148 (74%) patients who completed all intended neoadjuvant therapy and surgery and 13 months for the 53 (26%) who did not undergo surgery (p < 0.001). Conclusion: Pretreatment PET/CT avidity and preop CA19-9 are clinically significant prognostic markers in patients with PC.

Essential updates 2018/2019: Current topics in the surgical treatment of pancreatic ductal adenocarcinoma

“…Therefore, it is useful for considering the possibility of distant metastases in patients with resectable PDAC. 31,[38][39][40]…”

The role of FDG PET/CT or PET/MRI in assessing response to neoadjuvant therapy for patients with borderline or resectable pancreatic cancer: a systematic literature review

“…Some authors wrote that patients with higher baseline (pre-CRT) SUVs were associated with a better response to therapy [ 8 ], and a better overall survival (OS) [ 14 ]. SUVs remaining high after neoadjuvant therapy correlated with a poor prognosis [ 12 ].…”

“…Associating changes in SUV max with other PET measurements—such as metabolic tumor volume (MTV), total lesion glycolysis (TLG) or SUL peak —could improve the prediction of response to treatment and OS [ 18 ]. Barnes et al [ 14 ] found that PET data in association with carbohydrate antigen 19–9 (CA 19–9) levels could significantly predict outcome and response to CRT, though Panda et al [ 18 ] reported that CA 19–9 levels showed some limitations in predicting OS.…”

“…Patients with favorable SUVs but less favorable RECIST criteria after preoperative treatment would proceed to resection in the hope of benefiting from surgery. Indeed, a significant reduction in SUVs after CRT was also associated with a better prognosis after a median 40–44 months of follow-up [ 11 , 14 ]. On the other hand, a patient with an incomplete metabolic response or limited reduction in SUV max or SUV gluc on post-treatment metabolic imaging is unlikely to achieve a complete histopathological response after surgery.…”

Role of imaging in evaluating the response after neoadjuvant treatment for pancreatic ductal adenocarcinoma

“…However, the sample size of the above studies was relatively small (< 50 cases in 2/3 articles), and the results were not convincing. Barnes et al [ 55 ] enrolled 201 consecutive patients with localized PDAC treated with NAT. The results showed that the pre-treatment SUVmax cut-off value of 7.5 on PET/CT could accurately predict the OS.…”