Whole body PET/CT for initial staging of choroidal melanoma

AIM: To investigate the value of whole body positron emission tomography/computed tomography (PET/CT) in screening for metastatic choroidal melanoma in patients initially diagnosed with choroidal melanoma. METHODS: 52 patients with choroidal melanoma underwent whole body PET/CT as part of their metastatic investigation. PET/CT scans were used as a screening tool at the time of their initial diagnosis. A physical examination, liver function tests, and a baseline chest x ray were also obtained. PET/CT images (utilising intravenous18-fluoro-2-deoxyglucose (FDG)) were studied for the presence of metastatic melanoma. The standards for reference were further imaging and/or subsequent biopsies. RESULTS: Two of 52 (3.8%) patients were found to have metastatic melanoma before treatment. The most common sites for metastases were the liver (100%), bone (50%), and lymph nodes (50%). Brain involvement was also present in one patient. One patient (50%) had involvement of multiple sites. Haematological liver enzyme assays were normal in both patients. PET/CT showed false positive results in three patients (5.7%) when further evaluated by histopathology and/or additional imaging. In seven patients (13.4%) PET/CT imaging detected benign lesions in the bone, lung, lymph nodes, colon, and rectum. CONCLUSION: PET/CT imaging can be used as a screening tool for the detection and localisation of metastatic choroidal melanoma. Liver enzyme assays did not identify liver metastases, while PET/CT revealed both hepatic and extrahepatic metastatic melanoma. PET/CT imaging may improve upon the conventional methods of screening for detection of metastatic disease in patients initially diagnosed with choroidal melanoma.     

Combined positron emission tomography/computed tomography for evaluation of presumed choroidal metastases

BACKGROUND: Choroidal metastases are the most common intraocular malignancy and are the first sign of systemic malignancy in approximately one-third of patients. Of patients with no previous diagnosis of cancer, oncological evaluation fails to find the primary lesion in approximately 50% of cases. Newer imaging modalities such as combined positron emission tomography/computed tomography (PET/CT) may improve the yield of the systemic work-up. METHODS: Consecutive patients presenting with presumed choroidal metastases were evaluated with whole body combined PET/CT scanning. RESULTS: Four patients presenting to a tertiary referral hospital with choroidal metastases as the first sign of systemic malignancy were evaluated. In all four cases, PET/CT demonstrated the ocular lesion, and the primary malignancy which was confirmed by tissue biopsy. False-negative results were seen in two cases of cerebral metastases. PET/CT demonstrated lesions not visible on CT or magnetic resonance imaging in two cases. CONCLUSIONS: Combined PET/CT is a useful addition to the work-up of patients with choroidal metastases. It provides the opportunity to detect lesions not visible with other imaging modalities and the ability to image patients with contraindications to magnetic resonance imaging. It is essential to correlate PET images with clinical information and the results of other imaging modalities and tissue biopsy remains the gold standard in the diagnosis of malignancy. False positives and negatives can occur with PET/CT, and further research is needed before this promising technology becomes a routine part of the evaluation of patients with choroidal metastases.     

The relationship between combined positron emission tomography/computed tomography and clinical and light microscopic findings in choroidal melanoma

BACKGROUND: To investigate the correlation between the clinical and light microscopic features of choroidal melanoma with combined PET/CT findings. METHODS: This is a retrospective interventional case series of 14 patients with choroidal melanoma referred to the vitreoretinal service at the Mayo Clinic, Rochester, MN. All underwent preoperative combined PET/CT scanning and enucleation. Standardized uptake values (SUV) were correlated with the clinical and light microscopic features of the choroidal melanomas. RESULTS: All 14 eyes showed uptake. The mean patient age was 62 years (SD 12.5 years). The mean tumor thickness was 9.3 mm (range 3-23 mm). Histopathology showed choroidal melanoma in all with the following cell types: 6 mixed cell type, 7 spindle cell type, and 1 epithelioid cell type. The average of the SUV means was 3.7 (range 1.7-12.8). The individual SUV means were correlated with lesion thickness (r = 0.85; P < 0.01) and largest tumor basal diameter (r = 0.65; P = 0.01). Melanomas with focal necrosis (P = 0.03) and of the mixed cell type (P < 0.01) appeared to have higher SUV means. CONCLUSIONS: The majority of the choroidal melanomas had low to medium mean SUVs. Lesion size accounted for a significant portion of the variation, though nonspecific necrosis and cell type were also associated with higher SUV means.     

Whole-body fluorine-18 fluordeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in staging of advanced uveal melanoma

Fluorine-18 fluordeoxyglucose positron emission tomography (FDG-PET) is an useful tool in diagnosing and monitoring of malignant cutaneous melanoma. However, the feasibility and usefulness of FDG-PET in uveal melanoma is not yet established. We present a patient with suspected advanced uveal melanoma who underwent combined FDG-PET/computed tomography (CT) for staging. FDG-PET/CT images demonstrated vital intraocular tumor. Anatomical assignment of the malignancy to the choroid was possible by means of the coregistered computed tomography. Furthermore, PET revealed an unknown otherwise undetected vital liver metastasis. We conclude that combined FDG-PET/CT has potential to further improve staging and therapy planning in patients with advanced uveal melanoma.     

Value of positron emission tomography/computed tomography in diagnosis and staging of primary ocular and orbital tumors

Accurate and reliable staging methods are crucial for optimal care of patients with ocular and orbital malignancies. Positron emission tomography/computed tomography (PET/CT) has recently emerged as a staging tool in the field of ophthalmic oncology. For detecting primary ocular or orbital lesions, PET/CT does not seem to provide an advantage over clinical ophthalmologic examination or conventional imaging studies such as CT or magnetic resonance imaging of the orbit. However, PET/CT may detect distant metastatic lesions that conventional imaging studies miss. For orbital and ocular adnexal lymphoma, use of PET/CT has been proven to be feasible and is now accepted both as a standard part of the initial staging work-up and for the assessment of response to therapy. For other ophthalmic tumors, PET/CT seems most appropriate for advanced metastatic tumors of the orbit, eyelid, and eye, for which the detection of distant metastasis with 1 comprehensive study may be preferable to performing multiple CT scans with contrast.     

PET-CT在诊断眼部肿瘤全身转移中的价值

超声、CT、MRI等影像学检查方法对眼部肿瘤的定性、定位诊断具有重要意义,已广泛应用于临床。但对于确定恶性肿瘤发展程度、有无局部及全身转移,这些检查方法均不能一次完成。PET-CT应用计算机软件将PET和CT图像进行整合,同时得出显示病灶解剖部位和代谢异常的层面图像,通过定量分析病变区标准摄取值（SUV）进行诊断。目前已应用于脉络膜黑色素瘤、眼眶淋巴瘤、横纹肌肉瘤、泪腺腺样囊性癌等眼部恶性肿瘤及全身转移的诊断,为判断眼部肿瘤全身转移提供了新的诊断方法。     

Combined positron emission tomography/computed tomography imaging of orbital lymphoma

PURPOSE: To report a case of orbital lymphoma with systemic dissemination that was identified and localized by combined positron emission tomography (PET)/computed tomography. DESIGN: Case report. METHODS: A 75-year-old woman presented with a 6-month history of painless, progressive fullness of her right upper eyelid. A PET/computed tomography was obtained to provide functional and anatomic assessment of the orbits. An orbitotomy was performed with sub-total excision of the lesion to obtain histologic diagnosis. RESULTS: The PET/computed tomography scan revealed intensive uptake of tracer in a right orbital mass measuring 2.3 x 1.8 x 2.6 cm. Foci of abnormal tracer uptake were also noted in the right neck, right hilar region, and central abdomen. Histopathologic findings were consistent with follicular cell lymphoma. CONCLUSIONS: The combination of PET/computed tomography provides accurate and precise information in an expedited manner not offered by alternative imaging modalities. PET/computed tomography imaging should be considered in the evaluation of orbital neoplasms, especially if lymphoma is suspected.     

18-Fluorine-labelled 2-deoxy-2-fluoro-D-glucose positron emission tomography/computed tomography standardised uptake values: a non-invasive biomarker for the risk of metastasis from choroidal melanoma

AIMS: To correlate the clinical, ultrasound and pathological features of the eyes first evaluated by 18-fluorine-labelled 2-deoxy-2-fluoro-d-glucose (FDG) positron emission tomography (PET)/computed tomography and then enucleated for choroidal melanoma. METHODS: 14 consecutive patients enucleated for choroidal melanoma were examined. At presentation, clinical, ultrasound and PET/computed tomography imaging were carried out. Ultrasound was used to measure the tumour size and evaluate the tumour shape and intrinsic vascularity (blood flow). Histopathological and immunohistochemical evaluations included tumour cell type, necrosis, glycogen content, vascularity and extrascleral extension. RESULTS: 13 tumours were T3 and one T2 (American Joint Committee on Cancer - International Union against Cancer). The mean tumour height was 10.6 (range 3.5-17.7) mm with a largest basal dimension of 19.3 (range 14.5-30) mm. Patients having melanoma with the highest six standardised uptake values ((SUV) > or =4.0) were (on average) >10 years older, their melanomas had larger basal dimensions and were epithelioid-cell type; three melanomas were centred anterior to the equator; three contained enlarged blood vessels (>150 mum in diameter); and three formed extrascleral extension. Patients with the two highest SUV tumours died due to metastatic melanoma. CONCLUSION: PET/computed tomography imaging offers a physiological assessment of glucose metabolism in primary choroidal melanomas. Increased FDG PET/computed tomography SUV was positively correlated with known clinical, pathological and ultrasound features linked to metastatic potential of choroidal melanoma.     

Positron emission tomography in the diagnosis of orbital relapse of choroidal melanoma

CASE REPORT: A 72-year-old man with a large choroidal melanoma was treated with enucleation. Three years later MRI demonstrated images compatible with recurrent tumor in the orbit. PET studies showed no focal hypermetabolic abnormalities. DISCUSSION: In patients after enucleation of choroidal melanoma, conventional imaging techniques can fail to establish differentiation between malignant from post-surgery and benign anatomic abnormalities in orbital tissue that can be detected by PET scanning.     

Optical coherence tomography angiography characteristics of choroidal melanoma

PurposeThe purpose of this study is to evaluate tumour vasculature with optical coherence tomography angiography (OCTA) in malignant choroidal melanoma (CM).Materials and methodsPatients with unilateral CM were included in this cross-sectional observational clinical study. Applying OCTA systems operating at 840-nm wavelengths, eyes with CM were imaged. The primary main outcome measures were OCTA images, qualitative evaluation of macular and tumour vasculature, quantitative vascular density (VD), perfusion density (PD) and the foveal avascular zone disruption.ResultsThe study included 11 patients with unilateral CM and contralateral unaffected eyes as the control group. Eyes of 11 patients with CM and contralateral unaffected eyes were imaged before brachytherapy and 5 patients were imaged post brachytherapy. CM is demonstrated dense, tortuous blood vessels, uneven thickness and relatively disorganised intratumoural vasculature. In 11 eyes with CM, the VD and PD in the macular area were significantly lower within affected eyes (131.333 ± 27.807%, 3.152 ± 0.714%, p < 0.0001) than in contralateral eyes (154.208 ± 5.599%, 3.662 ± 0.127%, p < 0.0001). The VD and PD in the tumour area (67.990 ± 34.899%, 1.617 ± 0.847%, p < 0.0001) were significantly lower when compared to the macular area of affected eyes (131.333 ± 27.807%, 3.152 ± 0.714%, p < 0.0001) and the macular area of contralateral eyes (154.208 ± 5.599%, 3.662 ± 0.127%, p < 0.0001). After radiation treatment, the VD and PD in five CM eyes (116.526 ± 7.598%, 2.438 ± 0.358%, p < 0.05) were significantly lower than before treatment (141.544 ± 14.645%, 3.327 ± 0.354%, p < 0.05). Tumour regression after radiation therapy for melanomas was associated with decreased vessel density.ConclusionsOCTA can provide a dye-free, non-invasive, reliable method to monitor a variety of tumours, including CM for growth and vascularity. Upon OCTA, this could be helpful in evaluating the variety of tumour blood vessels before and after brachytherapy to judge the curative effect and whether the tumour recurred. Detection of the characteristic vascular features of CM by OCTA could make OCTA an assuring diagnostic modality to differentiate malignant lesions.Subject terms: Prognosis, Cancer     

Value of positron emission tomography in staging ocular adnexal lymphomas and evaluating their response to therapy.

BACKGROUND AND OBJECTIVE: An observational case series to assess the value of positron emission tomography (PET) in staging ocular adnexal lymphomas and evaluating their response to therapy. PATIENTS AND METHODS: The clinical records of 16 consecutive patients with ocular adnexal lymphoma for whom pretreatment and posttreatment PET scans and corresponding computed tomography (CT) and magnetic resonance imaging (MRI) scans were available were compared. RESULTS: Pretreatment PET scans demonstrated fluorine 18-fluorodeoxyglucose (FDG) positive lesions in 15 orbits of 12 patients. In 1 patient with low-grade follicular lymphoma of the orbit, PET revealed an additional focus of lymphoma in the deltoid muscle that was missed on clinical examination and conventional radiography. All of the posttreatment PET scans showed complete resolution of FDG uptake, suggesting good response to therapy. However, posttreatment CT and MRI scans demonstrated residual masses in 3 patients. CONCLUSIONS: PET is valuable for initial staging of ocular adnexal lymphomas and may be a good adjunct to conventional imaging in evaluation of response to therapy.     

Macroscopic study of choroidal and ciliary body melanoma

Uveal melanoma mainly affects the choroid and to a lesser extent the ciliary body. Its clinical presentation, as well as the angiographic and microscopic features are often reported. Its macroscopic appearance is less often reported in publications, however. The macroscopic study of these tumors provides useful information and a series of photographs illustrating the macroscopic study of these tumors was gathered to be shown to ophthalmologists who have little experience with these intraocular tumors.