PET- CT of the pancreas: The hot spots, the cold spots, the blind spots A quiz based review.

Transcription

1 PET- CT of the pancreas: The hot spots, the cold spots, the blind spots A quiz based review. Priyanka Jha 1,2, MD, Bijan Bijan 2, MD, MBA 1 Department of Radiology and Biomedical imaging University of California San Francisco San Francisco, CA 2 Department of Radiology University of California Davis Medical Center Sacramento CA

2 Goals and ObjecPves Depict the role of PET- CT in pancreapc malignancy: IniPal staging (local spread and distant metastases) Restaging and assessing treatment response Understanding artefacts and potenpal pitalls. Target audience: Abdominal imagers, oncologic imagers, nuclear medicine physicians, residents and fellows Disclosures: None

3 IdenPfy the findings present on the following images: q PancreaPc mass q Distant metastases PET- q Hypermetabolic pancreas focus q Distant metastases

4 IdenPfy the findings present on the following images: þ PancreaPc mass þ Vascular encasement þ Ductal dilatapon q Distant metastases PET- þ Hypermetabolic pancreas focus þ Vascular encasement q Distant metastases

5 Teaching points Contrast enhanced CT has been demonstrated to be superior to PET- CT in diagnosing vascular encasement. Crucial for establishing tumor resectability. PET- CT example demonstrates hypermetabolic focus encasing the SMA ospal calcificapons. Merits of PET- Close a[enpon on PET- CT may provide highly useful clues, when contrast enhanced CT may not be available.

6 IdenPfy the findings present on the following images: q PancreaPc mass q PancreaPPs q Distant metastases PET- q PancreaPc mass q PancreaPPs q Distant metastases

7 Imaging findings þ PancreaPc mass þ PancreaPPs þ Ductal dilatapon q Distant metastases PET- þ PancreaPc mass þ PancreaPPs q Distant metastases

8 Teaching points Hypermetabolic pancreapc mass on CT and PET- CT. Upstream ductal dilaton is present on CT. Fat stranding around the distal pancreas with low grade FDG uptake. Merits of PET- PancreaPc masses can obstruct the pancreapc ducts and cause post- obstrucpve pancreapps. PET- CT helps idenpfy the exact extent of the mass and differenpate it from post- obstrucpve inflammatory changes.

9 IdenPfy the findings present on the following images: q PancreaPc mass q Liver mass q Serosal implant PET- q PancreaPc mass q Liver mass q Serosal implants

10 IdenPfy the findings present on the following images: þ PancreaPc mass q Liver mass q Serosal implant PET- þ PancreaPc mass þ Liver mass þ Serosal implants

11 Teaching points Hypermetabolic pancreapc mass on CT and PET- CT. Hypermetabolic liver masses are seen. MulPfocal hypermetabolic implants are seen at the hepapc surface. Merits of PET- Small metastases (<2 cm) and serosal implants may be difficult to idenpfy on PET- CT. FDG uptake within these metastases, make them readily idenpfiable at PET- CT, allowing for accurate staging.

12 IdenPfy the findings present on the following images: q Post surgical changes q So` Pssue mass q Liver mass q PancreaPPs PET- q Post surgical changes q Hypermetabolic mass q Liver mass q PancreaPPs q A[enuaPon correcpon artefact

13 IdenPfy the findings present on the following images: þ Post surgical changes þ So` Pssue mass q Liver mass q PancreaPPs PET- q Post surgical changes q Hypermetabolic mass q Liver mass q PancreaPPs q A[enuaPon correcpon artefact

14 Teaching points Post surgical changes with adjacent so` Pssue a[enuapon is seen on CT. Findings suspicious for tumor recurrence. No FDG uptake on PET- CT at the site of so` Pssue. Merits of PET- So` Pssue a[enuapon at post surgical sites is common. CT can t differenpate post surgical changes from tumor recurrence. Complete absence of FDG uptake excludes tumor recurrence.

15 IdenPfy the findings present on the following images: q Post surgical changes q Mesenteric implants q Bowel mass q Osseous metastasis q Ascites PET- q Post surgical changes q Mesenteric implants q Bowel mass q Osseous metastasis q Ascites

16 Imaging findings q Post surgical changes þ Mesenteric implants q Bowel mass q Osseous metastasis q Ascites PET- q Post surgical changes þ Mesenteric implants q Bowel mass q Osseous metastasis q Ascites

17 Teaching points Mesenteric implants may be difficult to idenpfy on CT. DifferenPaPon from bowel loops may be difficult. Hypermetabolism on PET- CT allows for easy idenpficapon. Merits of PET- Mesenteric implants are more readily idenpfiable due to their hypermetabolic nature. More accurate staging results from accurate idenpficapon of metastasis.

18 IdenPfy the findings present on the following images: q Solid pancreapc mass q CysPc/necroPc pancreapc mass q Loco- regional nodal metastases q Distant metastases PET- q Solid pancreapc mass q CysPc/necroPc pancreapc mass q Hypermetabolic rim q Loco- regional nodal metastases q Distant metastases

19 Imaging findings q Solid pancreapc mass þ CysPc/necroPc pancreapc mass q Loco- regional nodal metastases q Distant metastases PET- q Solid pancreapc mass þ CysPc/necroPc pancreapc mass þ Hypermetabolic rim q Loco- regional nodal metastases q Distant metastases

20 DifferenPal diagnosis Which of the following will you include in the differenpal if this was a 20 year old female papent? q PancreaPc adenocarcinoma q Solid pseudopapillary epithelial neoplasm (SPEN) q Pancreatoblastoma q Complicated pancreapps q Mucinous neoplasm of the pancreas q Islet cell tumor q Lymphoma

21 DifferenPal diagnosis Which of the following will you include in the differenpal if this was a 20 year old female papent? q PancreaPc adenocarcinoma q Mucinous neoplasm of the pancreas þ Solid pseudopapillary epithelial neoplasm (SPEN) þ Pancreatoblastoma þ Complicated pancreapps q Islet cell tumor þ Lymphoma

22 Teaching points CysPc pancreapc mass idenpfied on both CT and PET- CT. DifferenPal in this young papent includes SPEN, pancreatoblastoma, complicated pancreapps and unlikely cyspc pancreapc adenocarcinoma. PaPent had biopsy- proven necropzing pancreapps. Poten0al pi4all: Inflammatory processes can mimic malignancy and cause false posipve results.

23 IdenPfy the findings present on the following images: q PancreaPc mass q Lung mass q Liver mass q Serosal implant PET- q PancreaPc mass q Lung mass q Liver mass q Serosal implants

24 Imaging findings q PancreaPc mass q Lung mass q Liver mass q Serosal implant PET- q PancreaPc mass þ Lung mass q Liver mass q Serosal implants

25 Teaching points No lung mass seen on CT. Hypermetabolic lung mass seen at right lung base. Pi4all of PET- MisregistraPon of hepapc acpvity leads to false impression of a lung nodule on PET- CT. Complete lack of corresponding CT abnormality should point to a possible misregsitrapon artefact. MoPon between CT and PET porpons of the exam leads to misregistrapon artefact.

26 IdenPfy the findings present on the following images: q Post surgical changes q Liver mass PET- q PancreaPc mass q Liver mass q A[enuaPon correcpon artefact

27 IdenPfy the findings present on the following images: þ Post surgical changes q Liver mass PET- q PancreaPc mass q Liver mass þ A[enuaPon correcpon artefact

28 Teaching points Post surgical changes with metallic surgical clips/coils seen on CT. Hypermetabolic focus seen on PET- CT and a[enuapon corrected PET. No hypermetabolic mass present on non- a[enuapon corrected PET. Pi4all of PET- Metallic surgical clips can lead to a[enuapon correcpon artefacts and lead to overespmapon of FDG uptake on a[enuapon corrected images. Non- a[enuapon correcpon images should be closely scrupnized in post surgical areas and with lung and skin findings.

29 References 1. Low G, Panu A, Millo N, Leen E. MulPmodality imaging of neoplaspc and nonneoplaspc solid lesions of the pancreas. Radiographics Jul- Aug; 31(4): doi: /rg Takanami K, Hiraide T, Tsuda M, et al. AddiPonal value of FDG PET/CT to contrast- enhanced CT in the differenpapon between benign and malignant intraductal papillary mucinous neoplasms of the pancreas with mural nodules. Ann Nucl Med Aug;25(7): Belião S, Ferreira A, Vierasu I et al. MR imaging versus PET/CT for evaluapon of pancreapc lesions. Eur J Radiol Oct;81(10): doi: / j.ejrad Epub 2011 Dec Strobel K, Heinrich S, Bhure U, et al. Contrast- enhanced F- 18- FDG PET/ 1- stop- shop imaging for assessing the resectability of pancreapc cancer. J Nucl Med 2008; 49: Sahani DV, Bonaffini PA, Catalano OA et al. State- of- the- art PET/CT of the pancreas: current role and emerging indicapons. Radiographics Jul- Aug; 32(4):

30 Thank you for viewing our presentapon! Corresponding author: Bijan Bijan, MD, MBA