Investigation into the quantitative and qualitative characteristics of choroidal melanoma through magnetic resonance imaging and B-scan ultrasound

B-scan measurements of intraocular tumor heights intraoperatively, before and after radioactive plaque application: A comparative prospective study

PURPOSE

To assess the difference in intraocular tumors height measurements intraoperatively before and after radioactive plaque application.

METHODOLOGY

Twenty-four eyes of 24 patients with intraocular tumors, candidates for radioactive therapy, were included. Each tumor was measured at the same setting before and after plaque application independently by 3 sonographers, using a 20-MHz B-scan transducer. Mean pre-plaque and post-plaque measurements were calculated and recorded. An A-scan vector aided in identification of the inner and outer tumor surfaces.

RESULTS

Each patient was examined independently three times by three experienced ultrasonographers within the same setting to assess interobserver variability. There was no statistically significant difference between the 3 examiners' readings, with P-value 0.99 for pre-plaque height and 0.97 for post-plaque height. Mean pre-plaque height was 5.16±2.11mm, while post-plaque height was 5.51±2.1mm (P-value 0.001). The Spearman correlation test showed that initial tumor height was negatively correlated with the difference between both heights, but with no statistical significance.

CONCLUSION

Intraocular tumor height measurement differs significantly before and after plaque application. Use of the pre-plaque height is advised until further studies are performed to assess the effect of this difference on treatment outcomes.

Choroidal melanoma tumor profile and treatment pattern for newly diagnosed patients at a reference public hospital in Sao Paulo, Brazil

BACKGROUND

Choroid, ciliary body, and iris melanomas are often grouped as uveal melanoma, the most common intraocular primary malignancy. The purpose of the current study was to analyze the tumor profile of newly diagnosed cases of choroidal melanoma at a reference center in Sao Paulo, Brazil, and to investigate the frequency of eyes treated by enucleation that could have been treated with brachytherapy if available in the service.

METHODS

Medical records of patients referred to our service with initial diagnostic hypothesis of choroidal melanoma from July 2014 to June 2020 were analysed on demographics, diagnosis confirmation, tumor measurement by ultrasonography and established treatment. Data were evaluated on clinical and demographic characteristics as age, sex, affected eye, ultrasound parameters, and treatment management of patients with clinically diagnosed choroidal melanoma. Among the patients submitted to enucleation, we investigated how many could have been selected to receive brachytherapy.

RESULTS

From the 102 patients referred with the choroidal melanoma diagnosis hypothesis, 70 (68.62%) were confirmed. Mean measurements from the tumors in millimetres were: 9.19 ± 3.69 at height and 12.97 ± 3.09 by 13.30 ± 3.30 at basal. A total of 48 cases (68.57%) were enucleated, 8 (11.43%) were treated by brachytherapy in a different service, and 14 patients (20.00%) returned for enucleation at their original referral center. Out of the 48 patients enucleated, 26 (54.17%) could have been selected to brachytherapy treatment.

CONCLUSIONS

The results indicate a late diagnosis of choroidal melanoma cases referred to our service. Most enucleated cases could have been treated with brachytherapy if it was broadly available at the national public health insurance. Further public health political efforts should focus on early diagnosis and better quality of life post-treatment for oncologic patients.

Conversion Factor for B-Scan Ultrasound Measurement of Intraocular Tumors With and Without the Sclera

OBJECTIVES

To investigate the relationship between choroidal nevus and melanoma thickness measured with or without the sclera included by B-scan ultrasound and to present a simple conversion formula.

METHODS

Medical records were retrospectively reviewed for choroidal nevus or melanoma evaluated at the Mayo Clinic in Rochester, Minnesota, with B-scan ultrasound between February 4, 2004, and April 23, 2020. Charts were retrospectively reviewed for high-quality B-scan images in which the ultrasound transducer was perpendicular to the lesion, measuring the tumor thickness without the sclera included. Measurements were repeated with the sclera included for each patient. Univariate and multiple linear regression analyses were performed to identify factors correlated with scleral thickness.

RESULTS

There were 201 tumors included in the study, with a mean patient age ± SD of 61 ± 14 years, largest tumor basal diameter of 11.8 ± 4.8 mm, tumor thickness without the sclera included of 3.72 ± 2.7 mm, and thickness with the sclera included of 4.54 ± SD 2.8 mm. On the univariate analysis, factors associated with perceived scleral thickness by B-scan ultrasound included age (P < .001), tumor thickness (P < .001), and basal diameter (P = .06). On the multivariate analysis, factors associated with perceived scleral thickness included age and tumor thickness (P < .001) for all tumors and for the subset of 141 tumors with a thickness of 2 mm or greater (P < .001). For tumors of 2 mm or greater in thickness, perceived scleral thickness by ultrasound can be estimated by the formula 0.00495(patient age) + 0.02451(tumor thickness without the sclera) + 0.42549.

CONCLUSIONS

We present a simple formula for converting between B-scan ultrasound measurements of choroidal nevus and melanoma measuring 2 mm or greater in thickness with and without the sclera included.

Response Evaluation of Choroidal Melanoma After Brachytherapy Using Diffusion-Weighted Magnetic Resonance Imaging (DW-MRI): Preliminary Findings

Purpose: To evaluate the role of diffusion-weighted magnetic resonance imaging (DW-MRI) in the assessment of therapeutic response in patients with choroidal melanoma treated with brachytherapy.

Materials and Methods: We performed a prospective, unicentric study which included patients with choroidal melanoma and indication for brachytherapy. Three DW-MRI examinations were proposed for each patient, one before and two after treatment. The apparent diffusion coefficient (ADC) value was calculated on DW-MRI and compared with local tumor control assessed by ophthalmologic follow-up.

Results: From 07/2018 to 06/2019, 19 patients were recruited, 13 of whom underwent follow-up examinations. Patients' ages ranged from 24 to 78 years and 52.9% were male. At the ocular ultrasound, the mean tumor thickness and diameter were 6.3 and 11.5 mm, respectively. Two patients (15.4%) showed signs of tumor progression during follow-up (7 and 9 months after treatment). There was no statistically significant difference in tumor size between MR before and after treatment, however, there was a significant reduction in mean ADC in patients with progression (p = 0.02).

Conclusion: DW-MRI is a promising method for monitoring patients with choroidal melanoma; reduction in the mean ADC values between pre-treatment MRI and the first post-treatment MRI may be related to the lack of response to brachytherapy and increased risk of disease progression.