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B Damato

Publications and source records attributed to B Damato.

18 recordsLinked to original sources
PubMed2006

Double-blind evaluation and benchmarking of survival models in a multi-centre study.

Accurate modelling of time-to-event data is of particular importance for both exploratory and predictive analysis in cancer, and can have a direct impact on clinical care. This study presents a detailed double-blind evaluation of the accuracy in out-of-sample prediction of mortality from two generic non-linear models, using artificial neural networks benchmarked against a partial logistic spline, log-normal and COX regression models. A data set containing 2880 samples was shared over the Internet using a purpose-built secure environment called GEOCONDA (www.geoconda.com). The evaluation was carried out in three parts. The first was a comparison between the predicted survival estimates for each of the four survival groups defined by the TNM staging system, against the empirical estimates derived by the Kaplan-Meier method. The second approach focused on the accurate prediction of survival over time, quantified with the time dependent C index (C(td)). Finally, calibration plots were obtained over the range of follow-up and tested using a generalization of the Hosmer-Lemeshow test. All models showed satisfactory performance, with values of C(td) of about 0.7. None of the models showed a systematic tendency towards over/under estimation of the observed survival at tau=3 and 5 years. At tau=10 years, all models underestimated the observed survival, except for COX regression which returned an overestimate. The study presents a robust and unbiased benchmarking methodology using a bespoke web facility. It was concluded that powerful, recent flexible modelling algorithms show a comparative predictive performance to that of more established methods from the medical and biological literature, for the reference data set.

Benchmarking↗
PubMed2004

The EORTC ophthalmic oncology quality of life questionnaire module (EORTC QLQ-OPT30). Development and pre-testing (Phase I-III).

AIMS: The research objective was to develop a questionnaire module to be used, in addition to the European Organisation into Research and Treatment of Cancer (EORTC) QLQ-C30, for measurement of quality of life (QL) among patients with uveal melanoma treated with methods such as transpupillary thermotherapy, plaque radiotherapy, proton beam radiotherapy, local resection, and enucleation. The present paper describes the development through Phases I-III. METHODS: Relevant QL issues were generated from literature search and from interviews with ophthalmologists, nurses, and patients with uveal melanoma representing three major treatment options: enucleation, plaque brachytherapy, and proton beam therapy. RESULTS: The provisional module was pretested in 61 patients from Finland, Sweden, and UK. The EORTC QLQ-OPT30 module consists of 26 items for all patients, and four additional items for patients receiving treatments other than enucleation. It measures ocular irritation, vision impairment, headache, worry about recurrent disease, problems with driving, problems with appearance functional problems due to vision impairment, and problems reading. CONCLUSIONS: Several treatment modalities are available for uveal melanoma. There is limited knowledge of the impact of these treatments on QL in the long and short term. We hope that the OPT30 module together with the EORTC QLQ-C30 core questionnaire can be a useful tool in research.

Adult↗
PubMed2003

The subjective experience of early postoperative pain following retrobulbar anaesthesia for enucleation and primary orbital implant.

INTRODUCTION: We performed a prospective audit of the level of postoperative pain experienced by patients following enucleation with insertion of a primary orbital implant after preincisional regional retrobulbar anaesthesia using bupivacaine 0.75% with 1:100,000 adrenaline. MATERIALS AND METHODS: An 11-point numerical ranking box scale was used to measure the subjective experience of postoperative pain following enucleation with insertion of a primary orbital implant in 40 patients with uveal melanoma. Surgery was performed under general anaesthesia with a supplementary peroperative retrobulbar injection of bupivacaine 0.75%/adrenaline 1:100,000. Pain scores were measured for the first 8 hours following administration of the block. RESULTS: The sample included 19 female and 21 male patients with a mean age of 66.7 years (31-87). At four hours post block, 80% were still pain free with 17% experiencing only mild to moderate pain (BS-11 = 1-4). Thirty-four (85%), twenty-eight (70%) and twenty-seven (67%) patients remained pain free at 2, 3 and 4 hours, respectively with no additional analgesia. The remainder scored BS-11 of 1-4 in 92% of cases. Twenty percent required supplementary analgesia (paracetemol in 78% cases) by 5 hours and 57% by 8 hours. BS-11 at 8 hours were 0 in 50%, 1-4 in 22% and 5-10 in 10% of patients (17% asleep). No complications using this technique were recorded. DISCUSSION: Using a preincisional retrobulbar injection of bupivacaine with adrenaline, BS-11 pain scores remained low with no or minimal additional analgesia for up to 4 hours post surgery. In combination with oral analgesia, effective pain control was provided in most cases for up to 8 hours post block.

Adult↗
PubMed2001

Time to treatment of uveal melanoma in the United Kingdom.

PURPOSE: To measure delay before treatment of uveal melanoma. METHODS: A retrospective study was carried out of patients referred for diagnosis and treatment of uveal melanoma at the Liverpool Ocular Oncology Centre (LOOC), a tertiary adult ocular oncology service. Participants were patients with uveal melanoma presenting to an optometrist or general practitioner in the United Kingdom between 1997 and 2000. Main outcome measures were delay at each stage of the referral process according to route of referral and tumour size. RESULTS: Delays greater than 2 weeks occurred (1) between presentation to the optometrist or general practitioner and the ophthalmologist's examination in 50% of patients; (2) between the ophthalmologist's examination and receipt of the referral at the ocular oncology centre in 34%; (3) between receipt of referral at the oncology centre and first assessment at that centre in 16%; and (4) between first assessment at the oncology centre and treatment in 8%. The waiting time for the ophthalmologist's examination was greater if the optometrist referred the patient via the general practitioner instead of directly. The median overall delays between presentation and treatment were 129 days for small tumours, 50 days for medium-sized tumours and 34 days for large tumours. CONCLUSIONS: Many patients with uveal melanoma experience long delays before treatment. Patients wait longer to see an ophthalmologist if their tumour is small or if they are referred by the optometrist to the general practitioner instead of directly to the ophthalmologist. Several patients also experience long delays after seeing the ophthalmologist, some having a large tumour by the time of teatment.

Adult↗
PubMed2001

Detection of uveal melanoma by optometrists in the United Kingdom.

In the United Kingdom, most uveal melanomas are detected by optometrists. Prospectively collected data on patients with uveal melanoma presenting to optometrists were analysed retrospectively to determine: (a) the proportion of patients who were asymptomatic at the time of tumour detection, (b) the proportion of symptomatic patients reporting that their tumour was missed at their initial presentation and (c) the clinical features related to immediate tumour detection. The 223 patients had a mean age of 59.7 years, a mean tumour diameter of 11.3 mm and a mean tumour thickness of 4.6 mm. Symptoms were present in 122 patients (55%) and were associated with large tumour size (p < 0.0001) and male gender (p = 0.003), with more males tending to have a large tumour (p = 0.004). Seventy-nine percent of symptomatic patients reported that their tumour was detected at their first visit. Failure of tumour detection in symptomatic patients was associated with absence of tumour extension posterior to equator (p < 0.0001).

Adult↗
PubMed2001

Cell proliferation activity in posterior uveal melanoma after Ru-106 brachytherapy: an EORTC ocular oncology group study.

AIM: To evaluate the cell proliferation activity in posterior uveal melanomas after Ru-106 brachytherapy. METHODS: Eyes containing choroidal or ciliary body melanoma from seven ocular oncology centres, which were enucleated after first being treated by Ru-106 brachytherapy and which had enough melanoma tissue to enable histological assessment, were included. The 57 eligible specimens were divided into a group of 44 eyes that were enucleated because of tumour regrowth, and a non-recurrent group of 13 eyes that were enucleated because of complications such as neovascular glaucoma. 46 non-irradiated eyes harbouring uveal melanoma served as a control group. All specimens underwent routine processing. They were cut into 5 microm sections, and were stained with two main cell proliferation markers: PC-10 for PCNA and MIB-1 for Ki-67. The stained sections were assessed, and the cells that were positive in the immunostaining were counted in each section. The results were evaluated by various statistical methods. RESULTS: The PC-10 score showed a statistically significant difference across the three groups (p = 0.002). The control group showed the highest PC-10 score (median 31.0 PCC/HPF) followed by the tumour regrowth group (median 4.9 PCC/HPF). The lowest PC-10 scores were found in the non-recurrent tumours (median 0.05 PCC/HPF). The MIB-1 score in the control group (median 5.77 PCC/HPF) was similar to the regrowth group (median 5.4 PCC/HPF). In contrast, the MIB-1 score in the non-recurrent tumours was statistically significantly lower (median 0.42 PCC/HPF). The PC-10 and MIB-1 scores were similar in tumours composed of either spindle cells or epithelioid cells in all groups. CONCLUSIONS: The non-recurrent melanomas demonstrate significantly lower cellular proliferation activity than melanomas that showed regrowth or that were not irradiated at all. In our hands, PCNA gave more meaningful information than Ki-67. Our findings strongly support the need for treating regrowing posterior uveal melanoma either by enucleation or re-treatment by brachytherapy. On the other hand, also in the non-recurrent uveal melanomas there are viable cells with potential for proliferation, although fewer in number, with unknown capacity for metastatic spread. Therefore, the irradiated tumours should be followed for many years, probably for life.

Analysis of Variance↗
PubMed1999

A choroidal amyloid-rich neuroendocrine tumor: initial manifestation of Cushing syndrome.

A 57-year-old man with a history of hepatic adenocarcinoma was referred 3 years after his diagnosis with a choroidal tumor in the right eye. Results of a transscleral excision biopsy revealed the tumor to be an amyloid-rich neuroendocrine metastasis. The patient subsequently developed cushingoid features and investigations revealed ectopic corticotropin syndrome, an elevated urinary 5-hydroxyindoleacetic acid level, and neuroendocrine metastasis in several locations. The choroidal neuroendocrine metastasis stained negative for serotonin and corticotropin. The source of the ectopic corticotropin and the location of the primary tumor have not been found. This case demonstrates that disseminated neuroendocrine tumors may rarely cause ocular lesions before systemic endocrine sequelae arise.

Amyloidosis↗
PubMed1998

Endoresection of choroidal melanoma.

AIMS: The results of 52 endoresections for choroidal melanoma are reported. METHODS: The current technique involves vitrectomy, retinal incision over or peripheral to the tumour, haemostasis by raising intraocular pressure and by moderate hypotensive anaesthesia, choroidal incision around tumour, endoresection with vitrector, endodiathermy to bleeding points and residual tumour, fluid-air exchange to reattach retina, endolaser to achieve retinal adhesion around the coloboma and destroy residual tumour in the sclera, silicone oil injection with removal after 12 weeks, cryotherapy to the sclerotomies, and adjunctive ruthenium plaque radiotherapy in selected cases. RESULTS: Patients receiving primary endoresection had a mean age of 53 years, a mean largest basal tumour diameter of 8.2 mm, and a mean tumour thickness of 3.9 mm. 40 tumours extended to within 2 disc diameters of the optic disc, with 17 involving disc. Follow up ranged from 40 days to 7 years (median 20 months). At the last visit, 90% of eyes were retained, with vision of 6/6-6/12 (two), 6/18-6/36 (three), 6/60 to counting fingers (18), hand movements (nine), and light perception (four). The main complications were retinal detachment in 16 and cataract in 25. Secondary endoresection (11) was performed after plaque radiotherapy (four), photocoagulation (four), trans-scleral local resection (two), and proton beam radiotherapy (one), with retention of the eye in nine cases. By the close of the study, no patients developed definite local tumour recurrence but one died of metastatic disease 41 months postoperatively. CONCLUSION: Depending on tumour location, endoresection may conserve central vision or temporal field when radiotherapy would be expected to cause optic neuropathy. Longer follow up is necessary to establish the efficacy of tumour control.

Adult↗
PubMed1992

Steady-state visual evoked cortical potentials from stimulation of visual field quadrants. Optimizing pattern variables for the size of the field to be investigated.

The effects of check size and stimulus size were investigated to optimize the steady-state visual evoked cortical potentials from pattern-reversal stimulation of the visual field quadrants. Check sizes of 15', 30', 60', 90', 120' and 180' were investigated at a pattern reversal rate of 11.6 per second for field sizes varying from 2 degrees x 2 degrees to 24 degrees x 24 degrees. The visual evoked cortical potentials were recorded from mid occipital, right occipital and left occipital positions. In the inferonasal quadrant, the largest amplitudes were obtained with 30' and 60' check sizes; however, for these check sizes, the visual evoked cortical potential yielded limited additional information for field sizes greater than 4 degrees x 4 degrees and 6 degrees x 6 degrees, respectively. When a field size of 12 degrees x 12 degrees was investigated, a 90' check size was optimal. The results indicated that, with the above recording positions and check sizes of 15' to 120', there is an optimal number of pattern elements, 40 to 100, for stimulation of the inferonasal quadrant. This should be taken into account when a check size is selected to investigate a field quadrant of a particular size. Digital signal processing techniques were applied to analyze the visual evoked cortical potential, and the system shows promise for objective examination of the visual field.

Adult↗