Table 1.

Characteristics of selected papers

No.	Author, ref	Year of pub	Country	Study design	N of pts	Chemotherapy (alone or + RT)	Chemotherapy alone	CHT and RT	Type of scanner	N of PET scans	Time among PET scan	Outcome
1	Kittaka et al. [8]	2013	Japan	R	40	Gemcitabine-based chemoradiotherapy	No	Yes	PET/CT	2	Baseline and at least 8 weeks after the completion of radiation therapy	SUV measurement by FDG PET/CT can be a useful tool to select suitable candidates for preoperative CRT and subsequent resection, predicting the locoregional effect of preoperative CRT
2	Ielpo et al. [9]	2016	Spain	P	25	Gemcitabine and nab-paclitaxel	Yes	No	PET/CT	2	Baseline and preoperative scan	SUV from FDG PET can help in defining the response to therapy
3	Mellon et al. [10]	2017	USA	R	70	Gemcitabine or GTX or folfirinox or gem + abraxane or others	Yes	No	PET/CT	2	Baseline Post-CRT	Pre-operative PET/CT and CA19.9 response correlate with histopathologic tumor regression
4	Akita et al. [11]	2017	Japan	R	83	Gemcitabine-based chemoradiotherapy	No	Yes	PET/CT	2	Baseline and at least 8 weeks after the completion of chemoradiation	FDG PET/CT is useful to evaluate the efficacy of preoperative therapy for PDAC
5	Sakane et al. [12]	2017	Japan	R	25	Gemcitabine-based chemoradiotherapy	No	Yes	PET/CT	2	Baseline after the completion of therapy	Higher post-treatment SULpeak and positive MTV/TLG could predict the unfavorable histopathological effects of CRT in patients with pancreatic adenocarcinoma
6	Dalah et al. [13]	2018	USA	P	15	Gemcitabine or xeloda and folfirinox or gemcitabine and abraxane	Yes	No	PET/CT	2	Baseline after 3–7 weeks from the end of chemotherapy	FDG PET can be more informative than CT for the definition of response to therapy
7	Barnes et al. [14]	2020	USA	R	104	Gemcitabine-based chemoradiation or capecitabine-based chemoradiotherapy	No	Yes	PET/CT	2	Baseline and approximately 4 weeks following the completion of neoadjuvant therapy	CA19.9 monitoring mirrors quantitative changes in the burden of disease, SUVmax levels may provide complimentary information in estimating the tumor’s biologic behavior
8	Zimmermann et al. [15]	2020	Germany	P	18	Gemcitabine and oxaliplatin radiochemotherapy	No	Yes	PET/CT	3	Baseline PET after two courses of NAT after 10 weeks from NAT (chemo + RT)	FDG PET/CT may be a reliable method to evaluate response to the combined therapy
9	Yokose et al. [16]	2020	Japan	R	22	Gemcitabine and nab-paclitaxel or TS1 + cisplatin + mitomycin and radiotherapy	No	Yes	PET/CT	2	Baseline and 2–3 weeks after completion of neoadjuvant treatment	PERCIST more accurately reflected neoadjuvant treatment’s therapeutic effect on PDAC than RECIST
10	Barbour et al. [17]	2020	Australia	P	42	Gemcitabine and nab-gemcitabine	Yes	No	PET/CT	2	Baseline and after 15 days from the start of therapy	PET/CT cannot be able to detect an early response to nab-gem in patients with advanced pancreatic cancer
11	Panda et al. [18]	2020	USA	R	44	Gemcitabine and oxaliplatin radiochemotherapy	No	Yes	PET/MRI	2	Baseline and post-NAT	Metabolic metrics from PET/MRI and morphological metrics from CT may help assess pathologic response to NAT as well as predict survival. CA 19.9 does not correlate with the outcome

CHT +  chemotherapy, RT radiotherapy, R retrospective, P prospective, CRT chemoradiation therapy, PDAC pancreatic adenocarcinoma, SUL standardized uptake lean, MTV metabolic tumor volume, TLG total lesion glycolysis