Biology of Cancer and PET Imaging: Pictorial Review

Early metastasis in sentinel lymph node as seen on transaxial SPECT/CT and ¹⁸F-FDG PET/CT images of patient with newly diagnosed bilateral invasive lobular breast cancer. SPECT/CT shows right sentinel lymph node (arrows). ¹⁸F-FDG PET/CT shows mild uptake in right sentinel lymph node (arrows), found on biopsy to be metastasis. ¹⁸F-FDG uptake in left axillary lymph node was also due to metastasis. (Adapted from (38).)

¹⁸F-FDG PET images of various cancers and metastases (A–D), and PET images with various other radiotracers (E–I). (A) Right breast cancer (invasive ductal) with multiple metastases in bones, liver, right adrenal, and right axillary lymph nodes. (B) Right breast cancer (poorly differentiated neuroendocrine tumor) with multiple metastases in lungs, liver, and right axillary lymph nodes. (C) Colon cancer in splenic flexure (arrow), with large metastasis in liver. (D) Rapid progression of brain metastasis in patient with cancer in right lung. Whole-body image (left) demonstrated hypermetabolic right lung tumor. On initial PET/CT scan, there was mild focal uptake in tail of right putamen (top right, arrow), but 3 mo later (no treatment), significant increase in size and metabolic activity of metastatic focus in brain was seen (bottom right, arrow). (E) ⁶⁸Ga-DOTANOC PET image of patient with small-bowel carcinoid, showing primary tumor (left arrow) and multiple mesenteric metastases (right arrow), all with high somatostatin receptor binding. (F) ⁶⁸Ga-PSMA-11 PET image of patient with prostate cancer, showing diffuse bone and multiple abdominal and pelvic lymph node metastases. (G) 6-¹⁸F-fluoro-l-dopa PET image of patient with history of surgically treated well-differentiated ileal neuroendocrine tumor, showing intense uptake in multiple large hepatic metastases. (Adapted from (43).) (H) ⁶⁸Ga-FAPI PET image of patient with non–small cell lung carcinoma, showing intense uptake in primary tumor and metastatic foci in mediastinum and, bilaterally, in supraclavicular regions. (Adapted from (44).) (I)¹⁸F-fluoroestradiol PET image of patient with invasive lobular breast cancer, showing extensive bone and bone marrow involvement with high estrogen receptor binding. (Adapted from (45).)

Pulmonary LC in patient with prostate cancer. Whole-body PET and transaxial CT and ⁶⁸Ga-PSMA ligand images show widespread thickening of interlobular septae and diffusely increased radiotracer uptake. (Adapted with permission of (53).)

Massive pulmonary tumor emboli from intravascular tumor thrombus in patient with renal cell carcinoma. PET/CT and maximum-intensity-projection images demonstrate ¹⁸F-FDG accumulation in left renal tumor, which was continuously observed in left renal vein and extended into infradiaphragmatic inferior vena cava and left ovarian vein (C, D, and E, black arrows). ¹⁸F-FDG uptake in left distal pulmonary artery and right and left branches (A and E, white arrowheads) and right atrial cavity (B and E, white arrows) is also seen. (Reprinted with permission of (55).)

(A) Transaxial CT and ¹⁸F-FDG PET images of patient with tubular breast cancer show hypermetabolic primary tumor as well as linear mild activity representing intraluminal tumor uptake either in mammary duct extending to nipple or in lymphatic channel extending to Sappey plexus (arrows). (B) Infiltrating perihilar cholangiocarcinoma with peribiliary extension. Coronal T1-weighted contrast-enhanced MR image (top) shows enhancing tumor of confluence of right ducts (white arrow), intrahepatic ductal dilation, and enhancing right peribiliary extension (black arrow), and ¹⁸F-FDG PET maximum-intensity-projection image (bottom) shows ¹⁸F-FDG–avid perihilar tumor (white arrow) with peribiliary extension (black arrow). (Adapted from (56).)