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.
Conjunctival melanoma and PAM responded to mitomycin 0.04% topical chemotherapy; subepithelial nests appeared resistant to treatment. Treatment-related complications were acceptable. In this series, as primary and adjuvant therapy, topical mitomycin yielded an overall recurrence rate of 50%.
Aim: To determine the size of untreated choroidal melanomas resolved by whole body positron emission tomography fused with computed tomography (PET/CT). Methods: 50 consecutive patients with untreated choroidal melanomas underwent whole body PET/CT. A functionally fused helical CT scan and 18-fluoro-2-deoxyglucose (FDG) PET scans were employed. The tumours were identified (both quantitatively and qualitatively) and compared with clinical measurements derived from ophthalmoscopic, angiographic, and ultrasonographic imaging. Standardised uptake values (SUV) of more than 2.5 were considered positive. Results: Among the 50 patients with choroidal melanoma, PET/CT scan SUVs of more than 2.5 were noted in 14 (28%) tumours. No AJCC T1 class tumours, 33.3% of T2 melanomas, and 75% of T3 melanomas were physiologically identifiable on PET/CT. With respect to COMS group classifications, no small choroidal tumours, 33% of medium, and 75% of large melanomas were physiologically identifiable. The sole ring melanoma was identifiable on PET/CT imaging. The smallest tumour physiologically identifiable by PET/CT had basal dimensions of 365.9 and an apical height of 2.9 mm. Conclusion: Though PET/CT was found to be capable of physiologically identifying certain medium (T2) and most large sized (T3) choroidal melanomas, physiological imaging was not completely dependent upon tumour size. Functionally fused PET/CT localised the tumours within the eye and assessed their physiological activity. C ancer cells require a great deal of sugar (glucose) for metabolism and growth. Positron emission tomography/computed tomography (PET/CT) scanning utilises a radioactive form of glucose, called 18-fluoro-2-deoxyglucose (FDG) that accumulates within malignant cells because of their high rate of metabolism. The FDG injected patient is imaged on the whole body PET scanner in an effort to reveal tumours that may have been overlooked or difficult to characterise (as benign or malignant) by conventional computed tomography (CT), x ray, or magnetic resonance imaging (MRI).The CT portion of a PET/CT provides detailed information about the location, size, and shape of tumours but offers less information that can be used to differentiate between cancerous and normal structures (compared to PET). The dual modality, PET/CT scanner fuses an image that puts form and function on the same diagnostic page.Choroidal melanomas are the most common primary intraocular cancer in adults. 1The Collaborative Ocular Melanoma Study (COMS) group and others have concluded that indirect ophthalmoscopy, combined with ophthalmic ultrasonography and fluorescein angiography, can yield a diagnostic accuracy rate greater than 99%.2 However, strict selection criteria (patient and tumour specific) for COMS eligibility were based on size and. secondly, on appearance, shape, location, internal ultrasonic reflectivity, and angiographic evidence of tumour leakage.2 Though exhaustive, the diagnostic criteria employed by COMS did not include physiological imaging.
Aims: To develop a minimally invasive, maximally effective method to biopsy anterior segment tumours. Methods: A 25 gauge aspiration cutter (vitrector) was used to biopsy anterior segment tumours. The probe was introduced under sodium hyaluronate 1% and through a 1 mm incision. Aspiration (600 mm Hg) cutting (300 cpm) was performed to obtain specimens for cytology and histopathology. Results: Diagnostic material was obtained in nine of 10 (90%) cases. Diagnoses included iris naevus, iris stroma, malignant melanoma, melanocytoma, epithelial inclusion cyst, and sarcoid granuloma. All corneal wounds were self sealing. One patient developed a transient postoperative increase in intraocular pressure. Within the follow up of this study, no patients suffered intraocular haemorrhage, infection, cataract or vision loss. Conclusion: The Finger iridectomy technique was a minimally invasive and very effective biopsy technique. Aspiration cutting yielded relatively large pieces of tissue (and cells) used for cytopathological and histopathological evaluation. Small incision surgery allowed for rapid rehabilitation and no significant complications.
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