Whole-body 18 FDG PET/CT imaging for lymph node and metastatic staging of conjunctival melanoma.

AIM: To evaluate 18-fluoro-2-deoxyglucose (FDG) whole-body positron emission tomography/computed radiographic tomography (PET/CT) for lymph node and metastatic staging of patients with conjunctival melanoma. METHODS: Fourteen patients with T3 (n = 13) and T4 (n = 1) conjunctival melanoma (as defined in Chapter 42 of the AJCC staging manual) were staged for metastatic disease with PET/CT imaging with fusion. The patients had lymph node and clinical staging evaluations before PET/CT imaging. PET/CT images were studied for the presence and distribution of metastatic conjunctival melanoma (determined by standardised uptake values) and later confirmed by biopsy. MRI imaging was performed if abnormalities were noted on PET/CT images. RESULTS: Fourteen patients with conjunctival melanoma underwent PET/CT imaging. Seven were newly diagnosed (presurgical screening), and seven had undergone prior treatment (follow-up group). Only one patient with conjunctival melanoma (7.1%) was found to have metastatic disease on PET/CT imaging. Abnormal foci were found in the liver, lung, peritoneal cavity, lumbar spine as well as a supraclavicular node (T4N1M4). All liver function tests were normal. The mean length of follow-up after PET/CT imaging was 13 months (range 4-30 months). CONCLUSIONS: PET/CT imaging did not reveal any regional or systemic metastasis among 14 patients with advanced, diffuse and multifocal disease.

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.

Anterior chamber paracentesis cytology (cytospin technique) for the diagnosis of intraocular lymphoma.

AIM: To report on the diagnosis of intraocular lymphoma by aqueous cytology. METHODS: Four patients suspected of having intraocular lymphoma were evaluated by anterior chamber (AC) paracentesis with cytology (cytospin technique). All had a history of non-ocular lymphoma and presented with at least one plus anterior chamber cells despite intensive glucocorticoid therapy. A 25 gauge needle was inserted through clear cornea (bevel up), over the iris stroma, so as to drain the AC. The aqueous humour was sent for cytopathology (cytospin technique), culture, and sensitivity tests. RESULTS: All procedures were diagnostic. Three were lymphoma and the fourth was culture positive for Propionibacterium endophthalmitis. No secondary glaucoma, hyphaema, cataract or infections were related to AC paracentesis. CONCLUSIONS: In this series, AC aspiration cytology enhanced by the cytospin technique was an effective, minimally invasive alternative to vitrectomy based biopsy. This technique should be considered to rule in the diagnosis of intraocular lymphoma in selected cases with cells in the anterior chamber.

PET/CT imaging: detection of choroidal melanoma.

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 3x5.9 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.

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.

"Finger-tip" cryotherapy probes: treatment of squamous and melanocytic conjunctival neoplasia.

AIM: To describe the use of a new spatulated cryoprobe in treatment of conjunctival neoplasia. METHODS: A new cryoprobe design was submitted to Mira, Inc resulting in new hand held probes capable of producing homogeneous freezing over large surface areas. The active surface of the small, medium, and large spatulated probes are 8.5 mm2, 25.2 mm2, and 70 mm2. End freezing reduces the possibility of inadvertent freezing of adjacent tissues (outside the targeted zone). In this series, the probes were employed to treat patients with squamous and melanocytic conjunctival neoplasia. RESULTS: 12 consecutive patients with malignant conjunctival neoplasia were treated with these new cryotherapy probes. Techniques of probe construction and clinical use are described. Cryoburns of the cornea, sclera, and conjunctiva were formed and recorded by digital photography. Ophthalmic examinations before and after surgery demonstrated that no acute intraocular or adnexal complications occurred. No loss of visual acuity could be attributed to this use of the cryoprobes. CONCLUSION: "Finger-tip" cryoprobes were used to treat malignant conjunctival neoplasia (squamous and melanocytic). Probe design allowed for uniform freezing over large surface areas. This cryoprobe design appears to be ideal for treatment of conjunctival tumours.

The Finger iridectomy technique: small incision biopsy of anterior segment tumours.

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.

Laser photocoagulation for radiation retinopathy after ophthalmic plaque radiation therapy.

AIM: To evaluate the use of scatter laser photocoagulation to prevent radiation related retinopathy, maculopathy, and loss of vision. METHODS: This was an interventional case series. 66 eyes with posterior choroidal melanomas treated by ophthalmic plaque radiation therapy were reported. Of these patients, 50 were selected because they developed radiation retinopathy; 45 of these were treated with sector scatter laser photocoagulation to regress clinically evident radiation retinopathy. 16 additional patients (considered to be "high risk" to develop radiation retinopathy) were also treated. RESULTS: Radiation retinopathy was noted to appear at a mean interval of 26 months following plaque treatment. Laser photocoagulation regressed radiation retinopathy in 29 (64.4%) of the 45 patients treated after the onset of radiation retinopathy (17 with only retinopathy, 10 with a combination of retinopathy and maculopathy, and two with only maculopathy). Of the 16 patients who received laser treatment before clinical evidence of retinopathy, one developed radiation maculopathy and two retinopathy without maculopathy (all three responded to additional laser photocoagulation). In the 45 patient group, vision loss of more than three lines was attributable to radiation maculopathy in seven (15.5%). None of the patients in the prophylactic laser group lost more than three lines of vision as a result of maculopathy. CONCLUSION: Sector scatter argon laser photocoagulation induced regression of radiation retinopathy. Though early treatment of radiation retinopathy appears to be more effective, a more long term and prospective randomised study will be needed to prove efficacy.

Palladium-103 plaque radiation therapy for macular degeneration: results of a 7 year study.

AIM: To report 7 year results of ophthalmic plaque radiotherapy for exudative macular degeneration. METHODS: In a phase I clinical trial, 30 patients (31 eyes) were treated with ophthalmic plaque irradiation for subfoveal exudative macular degeneration. Radiation was delivered to a mean 2 mm from the inner sclera (range 1.2-2.4) prescription point calculated along the central axis of the plaque. The mean prescription dose was 17.62 Gy (range 12.5-24) delivered over 34 hours (range 18-65). Early Treatment Diabetic Retinopathy Study (ETDRS) type standardised visual acuity determinations, ophthalmic examinations, and angiography were performed before and after treatment. Clinical evaluations were performed in a non-randomised and unmasked fashion. RESULTS: At 33.3 months (range 3-4), 17 of 31 (55%) eyes had lost 3 or more lines of vision on the ETDRS chart, five (16%) had improved 3 or more lines, and the remaining nine (29%) were within 2 lines of their pretreatment visual acuity measurement. Overall, 45% of patients were within or improved more than 2 lines of their initial visual acuity. Five eyes developed macular scars, eight developed subsequent neovascularisation or haemorrhage, and three progressed through therapy. Two patients were lost to follow up. The most common finding of patients followed for 6 or more months (n=18 of 29 (62%)) was regression or stabilisation of the exudative process. No radiation retinopathy, optic neuropathy, or cataracts could be attributed to irradiation. CONCLUSION: Ophthalmic plaque radiation can be used to treat exudative macular degeneration. At the dose and dose rates employed, most patients experienced decreased exudation or stabilisation of their maculas. No sight limiting radiation complications were noted during 7 year follow up. Owing to the variable natural course of this disease, a prospective randomised clinical trial should be performed to evaluate the efficacy of plaque radiation therapy for exudative macular degeneration.