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We present a rare case of a 74-year-old woman who underwent 68Ga-DOTATOC PET/CT imaging for a suspected neuroendocrine tumor (NET) in the pancreatic head. PET/CT showed a solitary high somatostatis receptor (SSTR)-expressing lesion in the pancreatic head. Fine-needle aspiration of this lesion revealed a metastasis from a clear cell renal cell carcinoma (ccRCC). The patient had undergone nephrectomy 16 years prior due to ccRCC of the right kidney. Our case demonstrates that metastases originating from RCC can have high SSTR expression and therefore might mimic well-differentiated neuroendocrine tumors in 68Ga-DOTATOC PET/CT.

A 38-year-old woman presented for 18F-FDG PET/CT after multiple intra-abdominal surgical resections of a rare recurrent perivascular epithelioid cell tumor of the gastrointestinal tract. A solitary pelvic metastasis was detected, but surprisingly exhibited neither increased glucose consumption nor contrast enhancement on CT. Follow-up 18F-FDG PET/CT staging in the further disease course revealed multiple abdominal metastases, now, however, with markedly increased 18F-FDG uptake and intraoperatively correlating widespread peritoneal sarcomatosis. This case gives preliminary insight into monitoring of disease progression in metastatic perivascular epithelioid cell tumor, although the underlying pathophysiological bases for varying 18F-FDG uptake in PET/CT are not yet fully understood.

68Ga-DOTATOC PET/CT is a reliable imaging modality in the diagnosis and therapy planning of symptomatic meningiomas. We present a case of a 74-year-old woman where a supposed SSTR-positive sphenoid wing meningioma turned out to be a breast cancer metastasis. Our case shows that dural metastases from breast cancer might represent a clinical pitfall in 68Ga-DOTATOC PET/CT.

A 58-year-old man with history of resected rectal adenocarcinoma and synchronous unifocal pulmonary metastasis showed a solitary pulmonary relapse in follow-up CT after 3 years of complete remission. Resection was planned. Preoperative 18F-FDG PET/CT detected a high focal 18F-FDG uptake in the left main bronchus. Bronchoscopy showed a papillary endobronchial lesion that was biopsied. Histology confirmed distant colorectal metastasis. The initial treatment plan changed, and the recommendation for systemic therapy was made by a multidisciplinary oncology team. Endobronchial metastases are rare and difficult to detect in conventional CT. PET/CT is useful to uncover endobronchial metastasis, which may change patient management.

The objective of this study was to compare the accuracy in staging of various malignant tumors with whole-body magnetic resonance imaging (WB-MRI) using parallel imaging (PAT) and positron emission tomography–computed tomography (PET-CT).

The long-term outcome after heart transplantation (HTx) is essentially influenced by the occurrence and extent of cardiac allograft vasculopathy (CAV). Single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) has been shown to be a useful and cost-effective non-invasive method in patients with known or suspected coronary artery disease, but its role in detecting CAV remains unclear.

Introduction: The treatment of Charcot neuroarthropathy in the feet of diabetic patients has undergone fundamental changes in the last few years. Formerly, treatment was almost exclusively limited to nonoperative measures; since the late 1990s, however, current practice has shifted to early, stage-appropriate surgical therapy. The objective of this prospective study was to investigate the value of two types of positron emission tomography (PET) in the preoperative evaluation of diabetic patients with Charcot foot deformities. Materials and Methods: Ring [18F]FDG (2-fluoro-2-deoxy-glucose) and hybrid PET were compared to magnetic resonance imaging (MRI). MRI, ring PET, and hybrid PET imaging were used as part of the preoperative evaluation of 16 patients with type II diabetes mellitus. The diagnosis of Charcot neuropathy of the foot requiring operative treatment had been made on the basis of clinical and radiographic criteria. Results: Of 39 Charcot lesions confirmed at surgery, 37 were detected by ring PET, 30 by hybrid PET, and 31 by MRI. Conclusions: PET (ring or hybrid) can be used in the evaluation of patients with metal implants that would compromise the accuracy of MRI. Another advantage of PET is its ability to distinguish between inflammatory and infectious soft-tissue lesions, and between osteomyelitis and Charcot neuroarthropathy. The differentiation between Charcot neuroarthropathy and florid osteomyelitis provides the surgeon with important additional information that often is unavailable from MRI. Because it provides important additional data, ring PET may be preferable to radiography and MRI in the preoperative evaluation of patients with Charcot neuroarthropathy of the foot. Hybrid PET, because of its poorer resolution compared to ring PET, appears less suitable for routine clinical application.

Presurgical neoadjuvant chemotherapy has shown promise in the treatment of locally advanced breast carcinoma (LABC). Response assessment by clinical examination and mammography is difficult. This study evaluated and compared fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG-PET) and technetium-99m sestamibi scintimammography (SMM) as potential methods for the early assessment of tumour response to neoadjuvant chemotherapy in patients with LABC. Seven patients underwent PET and SMM [planar and single-photon emission tomography (SPET)] before beginning chemotherapy, after the first and second cycles of chemotherapy and after completing chemotherapy prior to surgery. PET and SMM results were evaluated visually and semi-quantitatively by calculating standardised uptake values (SUV) and tumour/lung ratios in the initial and subsequent studies. The findings were correlated with the initial clinical and mammographic findings and the final histopathological diagnoses. There was a highly significant correlation between SUVmean, SUVmaxand the tumour/lung ratio determined with SMM-SPET in the studies performed before and during neoadjuvant chemotherapy. All three patients with complete remission showed decreasing FDG and sestamibi uptake as early as 8 days after therapy. In the presurgical study, increased sestamibi and FDG uptake was no longer evident. Three patients had partial remission with clearly reduced but persisting focal FDG and sestamibi uptake after neoadjuvant therapy. One patient who did not respond to therapy had unchanged intense tracer uptake during chemotherapy that was evident with both techniques. An early decline in glucose metabolism or sestamibi uptake 8 days after beginning therapy did not necessarily predict complete tumour remission in the further course of chemotherapy. On the other hand, increased tracer uptake after the first cycle did not exclude a partial tumour response. After the second chemotherapeutic cycle both techniques were able to distinguish between complete and partial/no response. There was a good correlation between preoperative FDG and sestamibi uptake and the histopathologically determined tumour size. However, small residual invasive tumours in patients with clinically complete remission could not be visualised with either technique. The preliminary data demonstrate that sestamibi SMM is as useful as FDG-PET for the monitoring of tumour response to neoadjuvant chemotherapy.

Abstract.: This study evaluated and compared technetium-99m sestamibi scintimammography (SMM) and breast magnetic resonance imaging (MRI) results in patients with indeterminate mammograms to determine whether either technique can improve the sensitivity and specificity for the diagnosis of breast carcinoma. From 123 consecutive patients who underwent physical examination, mammography, SMM, and histopathologic confirmation, a subgroup of 82 patients presenting with indeterminate mammograms was studied. Sixty-eight patients underwent contrast-enhanced MRI. SMM results were scored on the basis of the intensity and pattern of sestamibi uptake. MRI images were scored on the basis of signal intensity increase after administration of contrast material as well as the enhancement pattern and speed of gadolinium uptake. The results obtained with the two techniques were compared and related to the final histopathologic diagnoses. Considering indeterminate findings as positive, the sensitivity of SMM was 79% and the specificity, 70%. MRI displayed a sensitivity of 84% and a specificity of 49%. When indeterminate results were considered negative, the sensitivity and specificity of SMM were 62% and 83%, respectively. MRI revealed a sensitivity and specificity of 56% and 79%, respectively. The calculated sensitivities and specificities demonstrate the diagnostic limitations of both SMM and MRI in the evaluation of patients with indeterminate mammographic findings. Due to the higher specificity, SMM may be the preferred modality in the evaluation of selected patients with breast abnormalities.

Ten children, ranging in age from 3 weeks to 11 years, with a history of primary cardiac tumors were studied by two-dimensional echocardiography and by ECG triggered magnetic resonance (MR) imaging (six of them had rhabdomyomas). Eighteen of 31 tumors with intracavitary extension diagnosed by echocardiography were detected by MR. In addition, three intracavitary tumors were found by MR but not by echocardiography. Only 2 of 15 intramural tumors detected by echocardiography were identified by MR. Magnetic resonance imaging is inferior to echocardiography in the detection of intramural rhabdomyomas, but superior in delineation of the intra- and extracardiac extension of nonrhabdomyomal tumors.