18F-FDG PET/CT with Contrast Enhancement for Evaluation of Axillary Lymph Node Involvement in T1 Breast Cancer

Background

¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography ((PET) safely predicts axillary status in patients with breast cancer, but is not sufficiently accurate in early breast cancer patients. This study analyzed the value of ¹⁸F-FDG PET/computed tomography (CT) with contrast enhancement in detecting axillary lymph node involvement in T1 breast cancer patients.

Methods

Contrast-enhanced ¹⁸F-FDG PET/CT was performed within 20 days of surgery in 143 breast cancer patients with tumors ≤2 cm in size. The patients underwent either axillary lymph node dissection (ALND) or sentinel lymph node biopsy (SLNB), and histopathology reports were used to provide the definitive diagnosis against which the contrast-enhanced ¹⁸F-FDG PET/CT study results were compared.

Results

The sensitivity, specificity, and negative and positive predictive values of contrast-enhanced ¹⁸F-FDG PET/CT in detecting axillary involvement were 70.0%, 92.2%, 88.8%, and 77.8%, respectively, in the entire series of 143 patients, with eight false-positive and 12 false negative results. The false-negative results were associated with the number of metastatic lymph nodes and the rate of FDG uptake.

Conclusion

Contrast-enhanced ¹⁸F-FDG PET/CT cannot replace histologic staging using SLNB in patients with breast cancer, but ¹⁸F-FDG PET/CT increases the sensitivity for predicting axillary node metastasis, and allows for a selective approach to either ALND or SLNB, even in patients with T1 breast cancer.     

Breast cancer staging in a single session: whole-body PET/CT mammography

Our objective was to compare the diagnostic accuracy of an all-in-one protocol of whole-body 18F-FDG PET/CT and integrated 18F-FDG PET/CT mammography with the diagnostic accuracy of a multimodality algorithm for initial breast cancer staging. METHODS: Forty women (mean age, 58.3 y; range, 30.8-78.4 y; SD, 12 y) with suspected breast cancer were included. For the primary tumor, we compared 18F-FDG PET/CT mammography versus MRI mammography; for axillary lymph node status, 18F-FDG PET/CT versus clinical investigation and ultrasound; and for distant metastases, 18F-FDG PET/CT versus a multimodality staging algorithm. Histopathology and clinical follow-up served as the standard of reference. The Fisher exact test evaluated the significance of differences (P < 0.05). Alterations in patient management caused by 18F-FDG PET/CT were documented. RESULTS: No significant differences were found in the detection rate of breast cancer lesions (18F-FDG PET/CT, 95%; MRI, 100%; P = 1). 18F-FDG PET/CT correctly classified lesion focality significantly more often than did MRI (18F-FDG PET/CT, 79%; MRI, 73%; P < 0.001). MRI correctly defined the T stage significantly more often than did 18F-FDG PET/CT (MRI, 77%; 18F-FDG PET/CT, 54%; P = 0.001). 18F-FDG PET/CT detected axillary lymph node metastases in 80% of cases; clinical investigation/ultrasound, in 70%. This difference was not statistically significant (P = 0.067). Distant metastases were detected with 18F-FDG PET/CT in 100% of cases, and the multimodality algorithm identified distant metastases in 70%. This difference was not statistically significant (P = 1). Three patients had extraaxillary lymph node metastases that were detected only by PET/CT (cervical, retroperitoneal, mediastinal/internal mammary group). 18F-FDG PET/CT changed patient management in 12.5% of cases. CONCLUSION: Our data suggest that a whole-body 18F-FDG PET/CT mammography protocol may be used for staging breast cancer in a single session. This initial assessment of the 18F-FDG PET/CT protocol indicates similar accuracy to MRI for the detection of breast cancer lesions. Although MRI seems to be more accurate when assessing the T stage of the tumor, 18F-FDG PET/CT seems able to more accurately define lesion focality. Although 18F-FDG PET/CT mammography was able to detect axillary lymph node metastases with a high sensitivity, this method cannot soon be expected to replace the combination of clinical examination, ultrasound, and sentinel lymph node biopsy for axillary assessment.     

Prospective evaluation of fluorine-18 fluorodeoxyclucose positron emission tomography in breast cancer for staging of the axilla related to surgery and immunocytochemistry

The noninvasive staging of axillary lymph nodes for metastases is investigated in patients with breast cancer prior to surgery by positron emission tomography (PET) with fluorine- l8-fluoro-2-deoxy-d-glucose (¹⁸F-FDG). In 124 patients with newly diagnosed breast cancer, whole-body PET was performed to determine the average differential uptake ratio (DUR) of¹⁸F-FDG in the axillary lymph nodes. Results were correlated with the number of the dissected lymph nodes, size of the primary tumor, tumor type, tumor grade, estrogen and progesterone receptors, DNA ploidy, and the proportion of cells in the synthetic phase of the cell cycle (S-phase). In this prospective study of 124 patients with breast carcinoma, PET correctly categorized all 44 tumor-positive axillary lymph nodes, a sensitivity of 100%. Sixty tumor-negative axillary lymph nodes were negative by PET and 20 tumor-negative axillary lymph nodes were positive by PET. No false-negative PET findings were encountered. A weak correlation was found between DUR and tumor size as well as between DUR and the S-phase of the tumor. In patients with breast carcinoma,¹⁸F-FDG PET can be of value in evaluating axillary lymph nodes for metastatic involvement prior to surgery. It is of particular importance that no false-negative PET findings were encountered, and axillary lymph node dissection might not be necessary in patients without axillary uptake by PET. The DUR of the positive axillary lymph nodes seems to bear a relationship with some of the purported prognostic parameters of the primary tumor.     

The value of dual-time-point 18F-FDG PET/CT for identifying axillary lymph node metastasis in breast cancer patients

Objective

The sensitivity of 18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) for detecting axillary lymph node (ALN) metastases in breast cancer is reported to be low. Several studies have shown, however, that dual-time-point ¹⁸F-FDG PET imaging provides improved accuracy in the diagnosis of certain primary tumours when compared with single-scan imaging. The purpose of this study was to assess whether the use of dual-time-point ¹⁸F-FDG PET/CT scans could improve the diagnostic accuracy of ALN metastasis in breast cancer.

Method

The study included 171 breast cancer patients who underwent pre-operative ¹⁸F-FDG PET/CT scans at 2 time-points, the first at 1 h after radiotracer injection and the second 3 h after injection. Where ¹⁸F-FDG uptake was in the ALN perceptibly increased, the maximum standardised uptake values for both time-points (SUVmax1 and SUVmax2) and the retention index (RI) were calculated. Correlation between the PET/CT results and post-operative histological results was assessed.

Results

The performance of 1 h and 3 h PET/CT scans was equal, with sensitivity 60.3% and specificity 84.7%, in detecting ALN metastasis. Out of 171 patients, 60 had ALNs with increased ¹⁸F-FDG uptake on 1 h or 3 h images. There was no significant difference in RI between the metastatic ALN-positive group and the node-negative group. The area under the receiver operating characteristic (ROC) curve for SUVmax1 was 0.90 (p<0.001) and 0.87 for SUVmax2 (p<0.001).

Conclusion

Dual time-point imaging did not improve the overall performance of ¹⁸F-FDG PET/CT in detecting ALN metastasis in breast cancer patients.Axillary lymph node (ALN) involvement is the key prognostic factor in patients with breast cancer [1]. Accurate assessment of axillary node status is therefore essential for both predicting outcome and choosing a therapeutic plan. The most reliable and accurate procedure for the examination of ALN is standard axillary lymph node dissection (ALND). However, the complications associated with ALND, such as lymphoedema, numbness of the skin of the upper arm and impairment of shoulder movement, lead to decreased quality of life [2]. Moreover, a significant proportion of breast cancer patients, especially those with small tumours, are node negative [3,4]. Therefore, a non-invasive modality for accurate staging of ALNs is needed to avoid unnecessary ALND.¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) and ¹⁸F-FDG PET/CT have a useful role in staging and therapeutic planning in breast cancer patients in that these modalities are used to identify unexpected metastasis and recurrence [5]. The sensitivity of ¹⁸F-FDG PET for detecting ALN metastasis in breast cancer staging is, however, reported to be relatively low [6,7]. Recently, immunohistochemistry and multistep section have improved the detection rate of axillary micrometastasis and the value of ¹⁸F-FDG PET in axillary staging has become more uncertain [6,8,9].Several studies have shown that ¹⁸F-FDG uptake by malignant tumours increases for hours after injection [10,11]. Thus, some investigators suggest advantages of using delayed PET or dual time-point PET images. In breast cancer, Boerner et al [12] reported that PET images made 3 h after ¹⁸F-FDG injection showed higher tumour-to-non-tumour and tumour-to-organ ratios, and enhanced lesion detectability when compared with 1.5 h images.The purpose of this study was to assess whether dual-time-point (1 h and 3 h) ¹⁸F-FDG PET/CT scans could improve the diagnostic accuracy of ALN metastasis in breast cancer.     

A seldom case of primary urethral malignant melanoma and breast cancer detected by (18)F-FDG PET/CT

In the 1(st )issue of HJNM for 2012 we read with interest a case where 3 different cancers were detected. Synchronous second malignancy can be incidentally detected in routine fluorine-18-fluoro-deoxy-glucose positron emission tomography/computed tomography ( (18)F-FDG PET/CT) imaging in approximately 1% of cancer patients with lungs being the most frequent site. We report the (18)F-FDG PET/CT scan for staging of the primary malignant melanoma of the urethra and for the detection of another malignancy in the breast in the same patient, since primary malignant melanoma of urethra is very seldom. A 65 years old post-menopausal woman presented with increased frequency of micturition, dysuria and a gradually enlarging mass protruding from the external urethral meatus. Fine needle aspiration cytology (FNAC) performed from the mass revealed malignant melanoma. On cystourethrescopy examination, a 4x4 cm blackish mass was noted at the external urethral meatus with a satellite nodule in the bladder trigone. Contrast enhanced CT (CeCT) of the pelvis showed soft tissue thickening along the urethra infiltrating urinary bladder neck and vagina. Analysis of (18)F-FDG PET/CeCT was performed to assess the extent of the disease. Intensely (18)F-FDG avid soft tissue mass (SUV(max): 20.1) was noticed along the entire length of the urethra with hypermetabolic right inguinal and left external iliac lymph nodes. In addition to (18)F-FDG uptake in the bladder wall and the vaginal wall, intense (18)F-FDG uptake was also seen in two soft tissue nodules in the right breast and in the axillary lymph nodes suggestive of a second primary in the breast. Cytological diagnosis of intraductal breast carcinoma was made after FNAC from the breast nodule. Urethral melanoma was treated with anterior exenteration and ileal conduit. Histopathology confirmed the diagnosis of primary malignant melanoma of urethra infiltrating the urinary bladder and anterior vaginal wall. Postoperative histopathology from the right inguinal and left external iliac lymph nodes revealed metastatic disease. The diagnostic contribution of PET/CT was crucial. Melanotic melanoma cells have a distinctive MRI signal, which may be helpful in diagnosis. In this case whole body MRI could have been of equal value for accurate staging of urethral melanoma, but whole body MRI is a cumbersome procedure and often is not practical. Primary urethral carcinoma is very rare and an annual ageadjusted incidence rate of 4.3 per 106 in males and 1.5 per 106 in females has been reported in USA. Primary malignant melanoma of the urethra is rare, representing less than 1% of all melanomas and 4% of urethral cancers. Furthermore, the incidence of two primary cancers is rare and is reported to be between 0.3% and 4.3%. Primary malignant melanoma of the urethra has a worse prognosis than its cutaneous counterpart, partly due to delayed diagnosis. At the time of diagnosis, urethral melanoma is usually deeply invasive and locally extended to the vagina or vulva or the corpora cavernosa. Inguinal lymph node metastases are present at diagnosis in half of the cases and distant metastases in one third of them. Positron emission tomography demonstrates specificity and accuracy of 94.7% and 73% respectively in detecting lymph nodal metastases. Sensitivity, specificity and accuracy of (18)F-FDG PET/CT in detecting metastases in high risk patients were 85%, 96%, 91% while for (18)F-FDG PET/CT with dedicated CT interpretation were 98%, % and 96%, respectively. Recently, the role of (18)F-FDG PET/CT in treatment response evaluation of melanoma patients has also been demonstrated. Incidental (18)F-FDG uptake in the breasts is rare, and the lesion may be malignant in up to 57% of the cases. To our knowledge no published literature is available on synchronous breast carcinoma and urethral melanoma. The reason why some patients are more prone to develop multiple cancers remains obscure. One possibility may be of a genetic predisposition linking the two cancers. Research suggests that mutations in CDKN2A, a gene that indicates high risk of developing melanoma, also puts carriers at an up to 3.8 times greater risk of breast cancer. Similarly, mutations in the gene of breast cancer susceptibility, BRCA2, increase carriers' risk of melanoma by as much as 2.58 times. In conclusion, we describe a case of two primary carcinomas: a unique urethral malignant melanoma and a breast carcinoma, detected and staged by (18)F-FDG PET/CT.     

Lymphadenopathy by Scrub Typhus Mimicking Metastasis on FDG PET/CT in a Patient with a History of Breast Cancer

We report the case of a 60-year-old woman with left-sided breast cancer who showed lymphadenopathy mimicking metastatic lesions. She underwent surveillance ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) after treatment. PET/CT demonstrated multiple lymphadenopathies with increased FDG uptake, most notably in the right axilla. She had an eschar on the right axillary area, and her serologic test was positive for anti-Orientia tsutsugamushi IgM antibody. Ten months after the treatment, follow-up FDG PET/CT and ultrasonography showed improvement in generalized lymphadenopathy.     

PET/CT与增强CT检测乳腺癌及其腋淋巴结转移的对照研究

目的探讨^18F-脱氧葡萄糖（FDG）PET／CT显像与螺旋CT增强扫描检测乳腺癌及其腋淋巴结转移的临床价值。方法27例乳腺肿块患者于同日行^18F—FDG PET／CT显像与CT增强扫描。患者俯卧于乳腺专用泡沫垫上接受检查，前者图像由3位核医学科医师采用目测法结合半定量法进行诊断，后者图像由3位影像科医师分析诊断；最后与病理检查结果对照。结果27例患者PET／CT与增强CT均发现31个乳腺肿块，病理检查证实其中21个为乳腺癌，10个为良性病变；发现腋淋巴结91个，共有66个转移（1例有双侧腋淋巴结转移）；PET／CT显像检测乳腺癌原发灶的灵敏度为80．95％，特异性为90％，阳性预测值为94．44％；检测淋巴结转移的灵敏度为89．39％，特异性为88％，阳性预测值为95．16％。增强CT检测乳腺癌原发灶的灵敏度为90．48％，特异性为60％，阳性预测值为82．61％；检测淋巴结转移的灵敏度为86．36％，特异性为52％，阳性预测值为82．61％。^18F—FDG PET／CT和增强CT对腋淋巴结状态的诊断与病理检查结果的列联系数分别为0．64和0．37；两者对乳腺癌及其腋淋巴结转移的诊断特异性差异有显著性（P〈0．05）；对直径〈2cm的病灶，^18F—FDG PET／CT诊断准确性明显高于增强CT（P〈0．05）。结论^18F—FDG PET／CT对诊断乳腺癌及其腋淋巴结转移的特异性均高于增强CT。     

Systemic Immune Response to Vaccination on FDG-PET/CT

A patient with newly diagnosed right lung cancer had transient ¹⁸F-fluorodeoxyglucose (FDG)-avid left axillary lymph nodes and intense splenic FDG uptake on positron emission tomography (PET)/computed tomography (CT). History revealed that the patient received a left-sided influenza vaccine 2–3 days before the examination. Although inflammatory FDG uptake in ipsilateral axillary nodes is reported, to our knowledge, this is the first report of visualization of the systemic immune response in the spleen related to the influenza vaccination on FDG-PET/CT. The history, splenic uptake and time course on serial FDG-PET/CT helped to avoid a false-positive interpretation for progressing lung cancer and alteration of the radiation therapy plan.     

Multifocal Colonic Lesions Detected by 18F-FDG PET/CT: Correlation with Histopathology and Gross Specimen

A 73-year-old man underwent ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) for the staging of colon cancer. The ¹⁸F-FDG PET/CT revealed three colonic lesions. The histopathologic examination of the postoperative gross specimen revealed a tubular adenoma, a tubulovillous adenoma and an adenocarinoma. The maximal standardized uptake value (SUVmax) of a tubulovillous adenoma was much higher than that of adenocarcinoma. This patient could be considered as a representative case highlighting that SUVmax is not a reliable indicator for discriminating colon cancer from colonic adenomas.     

18F-FDG PET/CT in detection of gynecomastia in patients with hepatocellular carcinoma

ObjectiveWe retrospectively investigate the prevalence of gynecomastia as false-positive 2-[¹⁸F]fluoro-2-deoxy-d-glucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) imaging in patients with hepatocellular carcinoma (HCC).MethodsAmong the 127 male HCC patients who underwent ¹⁸F-FDG PET/CT scan, the ¹⁸FDG uptakes at the bilateral breasts in 9 patients with gynecomastia were recorded as standard uptake value (SUVmax) and the visual interpretation in both early and delayed images.ResultsThe mean early SUVmax was 1.58/1.57 (right/left breast) in nine gynecomastia patients. The three patients with early visual score of 3 had higher early SUVmaxs.ConclusionGynecomastia is a possible cause of false-positive uptake on ¹⁸F-FDG PET/CT images.     

Hypermetabolic Axillary Mass on 18F FDG PET/CT: Breast Cancer Arising from Accessory Breast Tissue

Differential diagnosis among several causes of axillary malignant mass is important. The most common cause of palpable malignant axillary mass is metastatic lymphadenopathy. Although carcinoma arising from ectopic breast tissue is rare, the diagnosis should be kept in mind when evaluating malignant axillary mass. In this report we present a case with carcinoma arising from ectopic breast tissue. ¹⁸F FDG PET/CT was performed for the purpose of localizing primary breast cancer lesion and systemic evaluation. PET/CT showed hypermetabolic lesions only in the right axilla. There is no evidence of malignancy in both breasts. When nuclear physicians encounter a hypermetabolic axillary mass indicating malignant lesion without evidence of primary breast malignant lesion, carcinoma arising from ectopic breast tissue should be included in the differential diagnosis.     

Added value of dedicated axillary hybrid 18F-FDG PET/MRI for improved axillary nodal staging in clinically node-positive breast cancer patients: a feasibility study

Purpose

To investigate the feasibility and potential added value of dedicated axillary 18F-FDG hybrid PET/MRI, compared to standard imaging modalities (i.e. ultrasound [US], MRI and PET/CT), for axillary nodal staging in clinically node-positive breast cancer.

Methods

Twelve patients with clinically node-positive breast cancer underwent axillary US and dedicated axillary hybrid 18F-FDG PET/MRI. Nine of the 12 patients also underwent whole-body PET/CT. Maximum standardized uptake values (SUVmax) were measured for the primary breast tumor and the most FDG-avid axillary lymph node. A positive axillary lymph node on dedicated axillary hybrid PET/MRI was defined as a moderate to very intense FDG-avid lymph node. The diagnostic performance of dedicated axillary hybrid PET/MRI was calculated by comparing quantitative and its qualitative measurements to results of axillary US, MRI and PET/CT. The number of suspicious axillary lymph nodes was subdivided as follows: N0 (0 nodes), N1 (1–3 nodes), N2 (4–9 nodes) and N3 (≥ 10 nodes).

Results

According to dedicated axillary hybrid PET/MRI findings, seven patients were diagnosed with N1, four with N2 and one with N3. With regard to mean SUVmax, there was no significant difference in the primary tumor (9.0 [±5.0] vs. 8.6 [±5.7], p = 0.678) or the most FDG-avid axillary lymph node (7.8 [±5.3] vs. 7.7 [±4.3], p = 0.767) between dedicated axillary PET/MRI and PET/CT. Compared to standard imaging modalities, dedicated axillary hybrid PET/MRI resulted in changes in nodal status as follows: 40% compared to US, 75% compared to T2-weighted MRI, 40% compared to contrast-enhanced MRI, and 22% compared to PET/CT.

Conclusions

Adding dedicated axillary 18F-FDG hybrid PET/MRI to diagnostic work-up may improve the diagnostic performance of axillary nodal staging in clinically node-positive breast cancer patients.

     

Role of 18F-FDG PET/CT in the prediction of gastric cancer recurrence after curative surgical resection

Purpose

The study evaluated the role of preoperative ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT in the prediction of recurrent gastric cancer after curative surgical resection.

Methods

A total of 271 patients with gastric cancer who underwent ¹⁸F-FDG PET/CT and subsequent curative surgical resection were enrolled. All patients underwent follow-up for cancer recurrence with a mean duration of 24?±?12?months. ¹⁸F-FDG PET/CT images were visually assessed and, in patients with positive ¹⁸F-FDG cancer uptake, the maximum standardized uptake value (SUV_max) of cancer lesions was measured. ¹⁸F-FDG PET/CT findings were tested as prognostic factors for cancer recurrence and compared with conventional prognostic factors. Furthermore, ¹⁸F-FDG PET/CT findings were assessed as prognostic factors according to histopathological subtypes.

Results

Of 271 patients, 47 (17?%) had a recurrent event. Positive ¹⁸F-FDG cancer uptake was shown in 149 patients (55?%). Tumour size, depth of invasion, presence of lymph node metastasis, positive ¹⁸F-FDG uptake and SUV_max were significantly associated with tumour recurrence in univariate analysis, while only depth of invasion, positive ¹⁸F-FDG uptake and SUV_max had significance in multivariate analysis. The 24-month recurrence-free survival rate was significantly higher in patients with negative ¹⁸F-FDG uptake (95?%) than in those with positive ¹⁸F-FDG uptake (74?%; p?18F-FDG uptake was a significant prognostic factor in patients with tubular adenocarcinoma (p?=?0.003) or poorly differentiated adenocarcinoma (p?=?0.0001). However, only marginal significance was shown in patients with signet-ring cell carcinoma and mucinous carcinoma (p?=?0.05).

Conclusion

¹⁸F-FDG uptake of gastric cancer is an independent and significant prognostic factor for tumour recurrence. ¹⁸F-FDG PET/CT could provide effective information on the prognosis after surgical resection of gastric cancer, especially in tubular adenocarcinoma and poorly differentiated adenocarcinoma.     

Pseudomesotheliomatous lung cancer mimicking mesothelioma on 18F-FDG PET/CT images: report of 2 cases

The authors report two cases of pseudomesotheliomatous lung cancer (PLC) detected by ¹⁸F-FDG PET/CT scan. ¹⁸F-FDG PET/CT clearly revealed the extent of the disease in both cases, a case of adenocarcinoma of the lung and a case of squamous cell carcinoma of the lung. Intense ¹⁸F-FDG uptake by the diffusely thickened pleurae and primary lesion was observed in both cases, and increased ¹⁸F-FDG uptake by a pelvic bone metastasis was observed in the case of squamous cell carcinoma. Although PLC is indistinguishable from malignant pleural mesothelioma on ¹⁸F-FDG PET/CT scans, ¹⁸F-FDG PET/CT was helpful in identifying the primary focus of the PLCs and in staging the disease. Diagnostic image interpreters should be familiar with the ¹⁸F-FDG PET/CT findings in PLC.     

Pictorial review of <Superscript>18</Superscript>F-FDG PET/CT findings in musculoskeletal lesions

We herein reviewed ¹⁸F-fluoro-2-deoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) findings in a number of musculoskeletal lesions including malignant tumors, benign tumors, and tumor-like lesions with correlations to other radiographic imaging modalities, and described the diversity of the ¹⁸F-FDG PET/CT findings of this entity. Malignant primary musculoskeletal tumors are typically ¹⁸F-FDG avid, whereas low-grade malignant tumors show mild uptake. Benign musculoskeletal tumors generally show a faint uptake of ¹⁸F-FDG, and tumor-like conditions also display various uptake patterns of ¹⁸F-FDG. Although musculoskeletal tumors show various uptakes of ¹⁸F-FDG on PET/CT, its addition to morphological imaging modalities such as CT and MRI is useful for the characterization and differentiation of musculoskeletal lesions.     

Primary Pulmonary Low-Grade Angiosarcoma Characterized by Mismatch between 18F-FDG PET and Dynamic Contrast-Enhanced CT

We report a rare case of primary pulmonary low-grade angiosarcoma on dynamic contrast-enhanced CT and ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT imaging. A 38-year-old, asymptomatic woman was hospitalized because of an abnormality on chest radiography. A dynamic contrast-enhanced chest CT showed a 1.2 cm-sized irregular-margined nodule with strong and persistent enhancement in the right lower lobe. The lesion had low metabolic activity on an ¹⁸F-FDG PET/CT scan. The patient underwent a wedge resection for the lesion, and pathology revealed a primary pulmonary low-grade angiosarcoma.     

Nonfunctioning endocrine pancreatic tumor examined with 18F-FDG PET/CT

A 71-year-old woman with type 2 diabetes mellitus complained of generalized fatigue. A 36-mm tumor in the pancreatic tail was detected with ultrasonography. The tumor was found to have marked hypervascularity with contrast-enhanced computed tomography (CT) and magnetic resonance. Combined ¹⁸F-fluorodeoxyglucose positron emission tomography and CT (¹⁸F-FDG PET/CT) showed ¹⁸F-FDG by the tumor with a maximal standardized uptake value of 2.98 at 50 min and 3.29 at 100 min following injection of ¹⁸F-FDG. ¹⁸F-FDG PET/CT suggested no extrapancreatic spread of the tumor. The patient had no pancreatic hormone-associated symptoms. Distal pancreatectomy was performed, and a well-differentiated endocrine tumor was diagnosed. The resected specimen showed neither infiltration of adjacent structures nor metastasis to regional lymph nodes. The present case suggests that ¹⁸F-FDG PET/CT is a reliable modality for staging endocrine pancreatic tumors.     

Unusual Horner’s Syndrome in Recurrent Breast Cancer: Evaluation Using <Superscript>18</Superscript>F-FDG PET/CT

¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a widely used imaging modality in the initial diagnosis of cancer, treatment response evaluation and detection of recurrence. Herein, we present the case of a 39-year-old female who presented right ptosis on the follow-up of breast cancer after surgery. Clinicians suspected Horner’s syndrome, and the patient underwent FDG PET/CT for the evaluation of recurrence that could cause Horner’s syndrome. FDG PET/CT demonstrated a focal hypermetabolic lesion in the right cervicothoracic junction area, corresponding to the preganglionic cervical sympathetic trunk. A subsequent needle biopsy was done, and the lesion was confirmed as metastatic ductal carcinoma. In this case, we could detect the exact location of the recurring lesion that caused Horner’s syndrome using FDG PET/CT.     

18F-FDG PET/CT and PET/MRI fusion imaging for neuroendocrine carcinoma of the tongue: A case report

Neuroendocrine carcinoma (NEC) involving the tongue is a rare and aggressive disease that is more common in middle-aged and elderly males. We report a case of a 56-year-old male who presented to our hospital with sore throat and was found to have a mass in the left root of the tongue. ¹⁸F-FDG PET/CT revealed intense FDG uptake in the mass of the tongue base, as well as different uptake of FDG in the mid-posterior mediastinal mass, right adrenal gland, and enlarged lymph nodes in the neck and mediastinum. Gadolinium-enhanced MRI clearly showed the extent of the tongue lesion, additionally suggesting the presence of brain metastases. ¹⁸F-FDG PET/MRI fusion images of the neck were obtained on the workstation, which may have a higher diagnostic value for tongue NEC. The patient underwent a biopsy of the mass in the left root of the tongue and was pathologically diagnosed with NEC. Whole-body ¹⁸F-FDG PET/CT and regional PET/MRI fusion images have complementary roles in the diagnosis of tongue NEC, and the former is mainly applied to determine the clinical stage of the disease and to guide treatment.     

18F-FDG PET/CT in Primary AL Hepatic Amyloidosis Associated with Multiple Myeloma

We report here on a rare case of primary AL hepatic amyloidosis associated with multiple myeloma in a 64-year-old woman. The patient was referred for evaluating her progressive jaundice and right upper quadrant pain. ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) showed diffusely and markedly increased ¹⁸F-FDG uptake in the liver. Although there have been several case studies showing positive ¹⁸F-FDG uptake in pulmonary amyloidosis, to the best of our knowledge, the ¹⁸F-FDG PET/CT findings of hepatic amyloidosis or primary hepatic amyloidosis associated with multiple myeloma have not been reported previously.