A 50-year-old male with pancreatic neuroendocrine cancer and metastases to the liver and bones. History of treatment with radiation therapy to the pancreatic mass, chemotherapy, chemoembolization, cold sandostatin, and radionuclide hepatic embolization in the past, presents with progressive disease. His symptoms include abdominal pain, nausea, vomiting, and diarrhea. His Karnofsky performance score is 70 and neuroendocrine markers are elevated: Chromogranin A of 58, Pancreastatin of 1920, and Gastrin of 358. FDG PET/CT image below (left) shows multiple bilobar hepatic metastases and two hypermetabolic foci in the bones: left scapula, and right side of pelvis. These lesions were positive on In-111 Octreotide imaging.

He met the inclusion and exclusion criteria for investigational PRRT (Peptide Receptor Radionuclide Therapy) with Lu-177 Octreotate, and received two cycles of therapy with 195.1 mCis and 191.0 mCis of Lu-177 Octreotate, 6 weeks apart. At the time that he presented for the third cycle of therapy, he was doing much better, and most of his symptoms had resolved. His Karnofsky performance score was 90 and there was a significant decrease in the levels of neuroendocrine markers: Chromogranin A of 3, Pancreastatin of 256, and Gastrin of 60. FDG PET/CT image above (right) shows good response to PRRT with partial response by RECIST criteria.

Representative images from MRI (above) show a significant improvement in liver metastases. The protocol includes IV injection of 200 mCi of Lu-177 Octreotate, 6-9 weeks apart, for a total of 4 cycles, for patients with unresectable metastatic neuroendocrine cancers, positive on In-111 Octreotide imaging. Patients are monitored closely for renal and hematologic toxicity.

1. Lutetium-labelled peptides for therapy of neuroendocrine tumours. Kam BL, Teunissen JJ, Krenning EP, de Herder WW, Khan S, van Vliet EI, Kwekkeboom DJ. Eur J Nucl Med Mol Imaging. 2012 Feb;39 Suppl 1:S103-12

2. Somatostatin receptor-targeted radionuclide therapy in patients with gastroenteropancreatic neuroendocrine tumors. Kwekkeboom DJ, de Herder WW, Krenning EP. Endocrinol Metab Clin North Am. 2011 Mar;40(1):173-85.

A 65 year old male presented with low back pain and weight loss. CT scan of the abdomen and pelvis showed moth eaten appearance of T12 vertebral body and bulky retroperitoneal, bilateral iliac and left inguinal lymphoadenopathy, concerning for metastatic disease, without any definite evidence of the primary.

FDG PET/CT demonstrated extensive hypermetabolic lymphadenopathy in the left supraclavicular, mediastinal, and retroperitoneal region consistent with metastatic disease. Widespread hypermetabolic bone metastases were also seen. Focal hypermetabolism was also seen in the prostate, with a maximum standardized uptake value (SUV) of 5.6. The PSA one month ago was elevated at 11.2 ng/ml. Metastatic poorly differentiated carcinoma was found on FNA biopsy of the left supraclavicualar node. Immunohistochemistry showed focal staining with TTF-1 and rare cells staining with PSA and synaptophysin with negative staining for CK7, CK20, CEA, p504, CDX2, CD20 and CD56, a pattern seen in small cell carcinoma of the prostate. Prostate biopsy confirmed adenocarcinoma with a Gleason’s score of 5+4=9.

PET/CT is not performed routinely to diagnose or stage prostate cancer, since the majority of prostate cancers are not FDG avid (1, 2). PET/CT although is indicated in patients with metastatic disease without a known primary. Focal hypermetabolism in the prostate is suspicious for neoplasm and should be further evaluation with tissue sampling to rule out malignancy. In patients with FDG avid prostate cancer, whole body PET/CT has been shown to provide additional information by identifying metastatic lesions (in soft tissues, lymph nodes, and skeleton) with one single whole body imaging procedure (3,4).

1: Ishiguro T, Kimura H, Araya T, Minato H, Katayama N, Yasui M, Kasahara K, Fujimura M. Eosinophilic pneumonia and thoracic metastases as an initial manifestation of prostatic carcinoma. Intern Med. 2008;47(15):1419-23.

2: Von Schulthess GK, Hany TF. Imaging and PET-PET/CT imaging. J Radiol. 2008 Mar;89(3 Pt 2):438-47.

3: Liu Y. FDG PET-CT demonstration of metastatic neuroendocrine tumor of prostate. World J Surg Oncol. 2008 Jun 19;6:64.

4: Jadvar H. Prostate cancer: PET with 18F-FDG, 18F- or 11C-acetate, and 18F- or 11C-choline. J Nucl Med. 2011 Jan;52(1):81-9.

This case was prepared by Dr. David He BCM

A 62 year-old man with non-ischemic cardiomyopathy was admitted for worsening shortness of breath and lower extremity swelling. DVT was ruled out on bilateral duplex ultrasound. The transthoracic echocardiogram showed a large heteroechogenic mass in the left ventricle, raising the possibility of intra-cardiac tumor. MRI was contraindicated due to AICD. FDG PET-CT was performed and demonstrated a large photopenic defect corresponding to the relatively homogenous hypodensity in the left ventricle, consistent with an intracardiac thrombus. The patient was treated for his CHF exacerbation and referred for heart transplant evaluation.

Intra-cardiac mass is a rare and serious condition. Imaging has an essential role in identifying the etiology. MRI has been successfully used to evaluate intra-cardiac masses including thrombi (1). FDG PET-CT has also been used to evaluate benign and malignant cardiac tumors presenting as an intracardiac mass (2-5). Compared to MRI, PET-CT is not limited by the presence of AICDs or metallic prosthesis. In addition, a negative PET-CT exam carries a very high negative predictive value to rule out primary or metastatic cardiac tumor.

1: Barkhausen J, Hunold P, Eggebrecht H, Schüler WO, Sabin GV, Erbel R, Debatin JF. Detection and characterization of intracardiac thrombi on MR imaging. AJR Am J Roentgenol. 2002 Dec;179(6):1539-44.

2: Gates GF, Aronsky A, Ozgur H. Intracardiac extension of lung cancer demonstrated on PET scanning. Clin Nucl Med. 2006 Feb;31(2):68-70.

3: Kim JH, Jung JY, Park Y, Hwang SI, Jung CS, Lee SH, Yoo CW. Non-small cell lung cancer initially presenting with intracardiac metastasis. Korean J Intern Med. 2005 Mar;20(1):86-9.

4: Bittner HB, Sharma AD, Landolfo KP. Surgical resection of an intracardiac rhabdomyoma. Ann Thorac Surg. 2000 Dec;70(6):2156-8.

5: Agostini D, Babatasi G, Galateau F, Grollier G, Potier JC, Bouvard G. Detection of cardiac myxoma by F-18 FDG PET. Clin Nucl Med. 1999 Mar;24(3):159-60.

This case was prepared by Dr. David He BCM

A 54 year old male with a history of hepatitis C, stage II colon cancer, status post left hemicolectomy presented for follow-up of a newly diagnosed left tonsillar squamous cell carcinoma. A whole body FDG PET/CT was preformed for staging, two months after the surgery for colon cancer. Focal hypermetabolism was seen in the left tonsillar mass and left level II lymphadenopathy. Incidentally noted increased uptake in the left upper quadrant of the abdomen was thought to be related to post surgical changes at the site of prior bowel anastomosis.

Patient also has history of recurrent MRSA infections (subcutaneous abscess in the lower extremity, groin, and axilla).

Soon after initiating chemotherapy patient was admitted for fever with chills and was found to have MRSA bacteremia. In-111 labeled leukocyte (WBC scan) study was performed with 657 microcuries to identify the source of infection. Planar images show ill defined focal uptake in the left upper quadrant of the abdomen, abutting the spleen.

The SPECT/CT images localize the focus to the splenic flexure of colon, at the site of prior bowel anastomosis, post left hemicolectomy. This abnormal accumulation of In-111 labeled WBCs was suspicious for active infection. A follow up contrast enhanced CT scan of the abdomen showed an abscess in this region, that was drained.

Early investigation of hybrid SPECT/CT imaging technology in localizing infection has been very promising. This could lead to a greater acceptance of this technology in a wide variety of additional clinical roles as well.

Bybel, B et al. SPECT/CT imaging: clinical utility of an emerging technology. Radiographics. 2008 Jul-Aug;28(4):1097-1113.

Heiba, S et al. The diagnostic confidence of SPECT & SPECT/CT in Indium-111 leukocyte scintigraphy. J Nucl Med. 2007; 48 (Supplement 2):63P.

This case was prepared by Dr. Raj R Chinnappan BCM

A 61 year old man with history of rheumatoid arthritis and hypertension presents with pain in left hip after a fall. X-ray of the pelvis did not show any fractures, but a sclerotic lesion in the right iliac wing was noted. A bone scan was recommended for further evaluation.

The whole body bone scan shows multiple foci of increased uptake in the pelvis, left chest wall, and the T5 vertebral body. The pelvic abnormalities were suspicious for metastatic disease.

The whole body FDG PET-CT found varying degrees of hypermetabolism at the sites of multiple fractures, at various stages of healing, corresponding to the bone scan findings, and suspicious for insufficiency fractures. No focal abnormal hypermetabolism was seen to suggest active neoplastic disease. On a follow up DXA scan patient was found to be osteoporotic, with a grade II wedge deformity of the T5 vertebral body. His osteoporosis was likely from chronic alcohol abuse and he was also found to have chronic alcoholic liver disease.

The whole body FDG PET-CT found varying degrees of hypermetabolism at the sites of multiple fractures, at various stages of healing, corresponding to the bone scan findings, and suspicious for insufficiency fractures. No focal abnormal hypermetabolism was seen to suggest active neoplastic disease. On a follow up DXA scan patient was found to be osteoporotic, with a grade II wedge deformity of the T5 vertebral body. His osteoporosis was likely from chronic alcohol abuse and he was also found to have chronic alcoholic liver disease.

1. http://www.springerlink.com/content/jq23mm975056j5m5/fulltext.pdf

2. http://www.ncbi.nlm.nih.gov/pubmed/16166836

3. http://www.jsnm.org/files/paper/anm/ams206/ANM20-6-11.pdf

This case was compiled by Dr. Niraj R Patel BCM

A 63 year old male who underwent total thyroidectomy for papillary thyroid carcinoma received 150 mCi of I-131 for remnant ablation, seen on whole body scan as two foci of iodine uptake in the anterior neck. He was found to have high serum thyroglobulin levels (107 mg/ml) on surveillance but the whole body I-131 scan (below) was negative for iodine avid recurrence or metastasis.

Whole body FDG PET-CT demonstrated hypermetabolic level IIb and level III lymphadenopathy. Right neck dissection was performed and out of the 15 nodes removed, four of were found to have metastatic papillary carcinoma. This case demonstrates the usefulness of PET-CT in detecting iodine negative but FDG avid metastatic thyroid carcinoma after total thyroidectomy.

1. Chung JK, So Y, Lee JS, Choi CW, Lim SM, Lee DS, Hong SW, Youn YK, Lee MC, Cho BY. Value of FDG PET in papillary thyroid carcinoma with negative 131I whole-body scan. J Nucl Med. 1999 Jun;40(6):986-92.

2. Palmedo H, Bucerius J, Joe A, Strunk H, Hortling N, Meyka S, Roedel R, Wolff M, Wardelmann E, Biersack HJ, Jaeger U. Integrated PET/CT in differentiated thyroid cancer: diagnostic accuracy and impact on patient management. J Nucl Med. 2006 Apr;47(4):616-24.

3. Finkelstein SE, Grigsby PW, Siegel BA, Dehdashti F, Moley JF, Hall BL. Combined [18F]Fluorodeoxyglucose positron emission tomography and computed tomography (FDG-PET/CT) for detection of recurrent, 131I-negative thyroid cancer. Ann Surg Oncol. 2008 Jan;15(1):286-92.

This case was compiled by Dr. David He, BCM

The patient is a 78 year old man with a history of a left neck glomus tumor diagnosed about 10 yrs ago, presented with complaints of worsening left thigh pain. X-ray showed a 2.4 cm lytic lesion in proximal left femur. CT-guided biopsy demonstrated metastatic neuroendocrine tumor.

A whole body FDG PET-CT showed intense focal hypermetabolism (SUV max 26) in the large left neck mass extending from the base of the skull to the superior aspect of the hyoid bone, invading the left petrous temporal bone, and encasing the internal carotid artery and jugular vein. Hypermetabolism was also seen in left level IIb lymph nodes (SUV max 9.5), a 1.4 cm nodule in the right lung base (SUV max 6.4), and a lytic lesion in the left proximal femur (SUV max 18.0).

A subsequent In-111 Octreotide scan showed increased tracer uptake in the left neck mass and femur, but not in the cervical lymph nodes or lung nodule. More metastatic lesions were seen on the FDG PET-CT compared to the Octreotide SPECT-CT. In the interim patient also had open reduction and internal fixation at the left femur.

Carotid body tumors are paragangliomas (extra-adrenal pheochromocytomas) arising from the carotid body. They arise close to or envelop the bifurcation of common carotid artery, usually in the sixth decade of life, and may be familial with autosomal dominant transmission in MEN 2 syndrome. They frequently recur after resection, many metastasize, and 50% ultimately prove fatal by direct invasion.

1. FDG PET imaging of paragangliomas of the neck: comparison with MIBG SPET. Macfarlane DJ, Shulkin BL, Murphy K, Wolf GT. Eur J Nucl Med. 1995 Nov;22(11):1347-50.

2. PET scan assessment of chemotherapy response in metastatic paraganglioma. Argiris A, Mellott A, Spies S. Am J Clin Oncol. 2003 Dec;26(6):563-6.

This case was compiled by Dr. Matthew R. Galfione, BCM

67 year old male with stage IIIA colon cancer, status post left hemicolectomy, low anterior resection and 6 months of adjuvant chemotherapy presented with rising CEA, an increase from 2.38 to 3.27 ng/ml. PET-CT showed a 8 mm non- FDG avid right lower lobe lung nodule without any definite evidence of recurrent or metastatic disease. The patient was otherwise asymptomatic and a non-smoker.

In the next 8-9 months the nodule slowly increased in size on follow up CT scans and the CEA increased to 7.89 ng/ml. Repeat PET-CT showed focal hypermetabolism in the right lower lung nodule with a maximum SUV of 4.0, now measuring 1.6 x 1.0 cm. No other evidence of FDG avid neoplastic disease was seen. FNA of the right lower lobe lung nodule showed poorly differentiated adenocarcinoma from colon primary. Focal uptake (inflammatory) is also seen in the cervical spine facet joint arthritis (on the left).

PET-CT has been shown to be better than CT for the evaluation of recurrent or distant metastatic disease, especially after recent surgical procedures that distort local anatomy (1). Although colorectal cancer metastasizes to the liver more commonly, isolated pulmonary metastasis can also occur. Aggressive resection of pulmonary metastasis can prolong survival in these patients (2).

1. Flamen P; Hoekstra OSl Homans F. Unexplained rising carcinoembryonic antigen (ECEA) in the postoperative surveillance of colorectal cancer; the utility of positron emission tomography (PET). Eur J Cancer 2001 May; 37(7):862-9.

2. Lee WS, Yun SH, Chun HK. Pulmonary resection for metastases from colorectal cancer: prognostic factors and survival. Int J Colorectal Dis. 2007 Jun;22(6):699-704.

This case was compiled by Dr. Saiyyeda Rahman, BCM