Superficial ocular malignancies treated with strontium-90 brachytherapy: long term outcomes

High-Dose-Rate Yttrium-90 (90Y) Episcleral Plaque Brachytherapy for Iris and Iridociliary Melanoma

Purpose

To describe a pilot study on the use of single-session, high-dose-rate, Food and Drug Administration-cleared, yttrium-90 (Y90) plaque brachytherapy for iris and iridociliary melanoma.

Design

A single-center, clinical case series.

Participants

Six consecutive patients were included in this study. Each was diagnosed with an iris or iridociliary melanoma based on clinical examination with or without biopsy.

Methods

Each tumor was staged according to the American Joint Committee on Cancer criteria and received Y90 eye plaque brachytherapy. The main variables were tumor size, patient age, sex, and method of diagnosis (clinical or biopsy). Surgical techniques, treatment durations, and ocular side effects were recorded. Local control was defined as a lack of tumor growth or regression determined by clinical examinations, including slit-lamp and gonio photography, as well as high-frequency ultrasound measurements. Toxicity parameters included acute and short-term corneal/scleral change, anterior segment inflammation, and cataract progression.

Main Outcome Measures

Local and systemic cancer control, tumor regression, visual acuity, as well as radiation-related normal tissue toxicity.

Results

High-dose-rate Y90 plaque brachytherapy was used to treat small (American Joint Committee on Cancer cT1) category melanomas. Single-surgery high-dose-rate irradiations were performed under anesthesia. Because of short treatment durations, high-dose-rate Y90 did not require the additional procedures used for low-dose-rate plaque (e.g., sutures, amniotic membrane epicorneal buffering, Gunderson flaps, and second surgeries for plaque removal). Only conjunctival recession was used to avoid normal tissue irradiation. High-dose-rate Y90 treatment durations averaged 8.8 minutes (median, 7.9; range, 5.8-12.9). High-dose-rate Y90 brachytherapy was associated with no periorbital, corneal (Descemet folds), or conjunctival edema. There was no acute or short-term anterior uveitis, secondary cataract, scleropathy, radiation retinopathy, maculopathy, or optic neuropathy. The follow-up was a mean of 16.0 (range 12-24) months. Evidence of local control included a lack of expansion of tumor borders (n = 6, 100%), darkening with or without atrophy of the tumor surface (n = 5/6, 83%), and a mean 24.5% reduction in ultrasonographically measured tumor thickness. There were no cases of metastatic disease.

Conclusions

High-dose-rate Y90 brachytherapy allowed for single-surgery, minimally invasive, outpatient irradiation of iris and iridociliary melanomas.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Exclusive Ru-106 brachytherapy for the management of a recurrent corneo: Conjunctival squamous cell carcinoma

BACKGROUND

We report a case of personalized exclusive brachytherapy treatment for the management of a highly recurrent squamous cell conjunctival carcinoma with corneal invasion.

CASE DESCRIPTION

This is a case of a Caucasian 81-years-old man who presented 10 years ago to our clinic with a pink-white para-limbal mass with dilated feeder arteries and mild leukoplakia. Excisional biopsy confirmed the presence of conjunctival intraepithelial neoplasia (CIN). Successively, he underwent two 4-weeks cycles of Mytomicin C topical therapy and a second excisional surgery, due to several recurrences of the lesion. At the last relapse, the pink-white peri-limbic mass which invaded the corneal limbus, determining corneal opacification from 5- to 7-clock hours, was confirmed by anterior segment optical coherence tomography (AS-OCT). Due to resistance to MMC therapy and chronic epitheliopathy, an AS-OCT guided exclusive radiotherapy plan was set: a Rhutenium-106 CCD plaque was applied directly over the afflicted corneal surface, the corneal limbus and the neighboring sclera for 24 hours. The remission of both conjunctival and corneal malignancy was complete 2 months after surgery and no signs of recurrence were highlighted at AS-OCT analysis at the 2-year follow up.

CONCLUSION

Brachytherapy treatment showed optimal management of both corneal and conjunctival involvement, with a free-of-disease follow-up of 24-months. This result suggests that, in specific conditions, Ru-106 brachytherapy could be an effective option of treatment even if not associated with surgical excision.

Yttrium-90 Episcleral Plaque Brachytherapy for Choroidal Melanoma

Purpose: To describe the first use of high-dose-rate yttrium-90 disc brachytherapy for choroidal melanoma. Methods: A 72-year-old patient had a cT1-category choroidal melanoma characterized by the presence of orange pigment, increasing subretinal fluid (SRF), and enlarging tumor thickness. It was treated with single-session, light-guided, light-defined yttrium-90-disc brachytherapy. Results: A specialized handheld applicator provided with 4 encircling lights was used to guide plaque placement and localize treatment. Unlike low-dose-rate plaques, high-dose-rate yttrium-90 required only 3 minutes 39 seconds. In this case, treatment did not require episcleral sutures, muscle relocation, outpatient dwell time, or a second surgery. High-dose-rate treatment improved radiation safety by eliminating perioperative exposure to health care personnel, the community, and the family. At the 13-month follow-up, the SRF and tumor thickness were diminished. There was no secondary cataract, radiation retinopathy, maculopathy, or optic neuropathy, and the visual acuity was 20/20. Conclusions: Yttrium-90 brachytherapy allowed for single-surgery, minimally invasive, outpatient irradiation of a choroidal melanoma.

Evaluation of physicochemical characteristics and centerline temperatures of Sr ceramic waste form

When disposing of spent fuel, nuclides such as Cs-137 and Sr-90, which generate short-term decay heat, must be removed from the spent nuclear fuel for efficient storage facility utilization. The Korea Atomic Energy Research Institute (KAERI) has been developing a nuclide management process that can enhance disposal efficiency by sorting and collecting primary nuclides and a technology for separating Sr nuclides from the spent nuclear fuels using precipitation and distillation. In this study, we prepared Sr ceramic waste form, SrTiO₃, using the solid-state reaction method to immobilize the Sr nuclides, and its physicochemical properties were evaluated. Moreover, the radiological and thermal characteristics of the Sr waste form were evaluated by estimating the composition of Sr nuclides considering the spent nuclear fuel history such as burn-up and cooling period. The waste form was found to be stable with good mechanical strength and leaching properties in addition to a low coefficient of thermal expansion, which would be advantageous for intermediate storage. Based on the experimental and radiological results, the centerline temperature of the waste form caused by Sr-90 nuclide was estimated using the steady-state conduction equation. The centerline temperature increased with increasing diameter of the waste form. When generating the SrTiO₃ waste form using the Sr nuclide recovered after a cooling period of 10 years, the centerline temperature was estimated to exceed the melting point of SrTiO₃ at a diameter of 0.275 m, under all burn-up conditions. These results provide fundamental data for the management and intermediate storage of Sr waste.

First clinical implementation of Yttrium-90 Disc Brachytherapy after FDA clearance

PURPOSE

Herein, we study if high-dose-rate (HDR) yttrium-90 (⁹⁰Y) brachytherapy could be utilized by medical physicists, radiation oncologists, and ophthalmic surgeons.

METHODS AND MATERIALS

Yttrium-90 (⁹⁰Y) beta-emitting brachytherapy sources received United States Food and Drug Administration clearance for episcleral treatment of ocular tumors and benign growths. Dose calibration traceable to the National Institute of Standards and Technology as well as treatment planning and target delineation methods were established. Single-use systems included a ⁹⁰Y-disc affixed within specialized, multifunction, handheld applicator. Low-dose-rate to high-dose-rate prescription conversions and depth-dose determinations were performed. Radiation safety was evaluated based on live exposure rates during assembly and surgeries. Clinical data for radiation safety, treatment tolerability, and local control was collected.

RESULTS

Practice parameters for the medical physicist, radiation oncologist, and ophthalmic surgeon were defined. Device sterilizations, calibrations, assemblies, surgical methods, and disposals were reproducible and effective. Treated tumors included iris melanoma, iridociliary melanoma, choroidal melanoma, and a locally invasive squamous carcinoma. Mean calculated ⁹⁰Y disc activity was 14.33 mCi (range 8.8-16.6), prescription dose 27.8 Gy (range 22-30), delivered to depth of 2.3 mm (range 1.6-2.6), at treatment durations of 420 s (7.0 min, range 219 s-773 s). Both insertion and removal were performed during one surgical session. After surgery, each disc-applicator- system was contained for decay in storage. Treatments were well-tolerated.

CONCLUSIONS

HDR ⁹⁰Y episcleral brachytherapy devices were created, implementation methods developed, and treatments performed on 6 patients. Treatments were single-surgery, rapid, and well-tolerated with short-term follow up.

In vivo dosimetry in pelvic brachytherapy

ADVANCES IN KNOWLEDGE

This paper describes the potential role for in vivo dosimetry in the reduction of uncertainties in pelvic brachytherapy, the pertinent factors for consideration in clinical practice, and the future potential for in vivo dosimetry in the personalisation of brachytherapy.

Synthesis of Ionizable Calix[4]arenes for Chelation of Selected Divalent Cations

Two sets of functionalised calix[4]arenes, either with a 1,3-crown ether bridge or with an open-chain oligo ether moiety in 1,3-position were prepared and further equipped with additional deprotonisable sulfonamide groups to establish chelating systems for selected cations Sr²⁺, Ba²⁺, and Pb²⁺ ions. To improve the complexation behaviour towards these cations, calix[4]arenes with oligo ether groups and modified crowns of different sizes were synthesized. Association constants were determined by UV/Vis titration in acetonitrile using the respective perchlorate salts and logK values between 3.2 and 8.0 were obtained. These findings were supported by the calculation of the binding energies exemplarily for selected complexes with Ba²⁺.

Systemic neoadjuvant chemotherapy in non-resectable invasive squamous cell carcinoma of ocular surface

BACKGROUND/OBJECTIVES

The conventional modality for management of advanced invasive ocular surface squamous neoplasia (OSSN) (AJCC grade T4 and T3 with fornicial involvement) is surgical excision which is not only challenging in terms of ability to achieve tumor free margins and tissue reconstruction but also has high morbidity. We describe the use of systemic neoadjuvant chemotherapy (NAC) in cases of advanced invasive OSSN.

SUBJECTS/METHODS

This is a retrospective case series. Five cases of histopathologically proven advanced OSSN that were challenging to manage with surgical excision or required exenteration were treated with NAC. Demographic details, previous treatment history, location and extent of tumor, imaging findings, number of cycles and duration of NAC, response to treatment, and final outcome on follow-up were noted.

RESULTS

A remarkable response to NAC was seen in 4/5(80%) cases. Complete regression was seen in 2/5, partial regression in 2/5, and no response in 1/5 cases. In 75% (3/4) cases who showed response to NAC, minimal or no surgery was required. Exenteration was avoided in 2/3 cases with orbital extension.

CONCLUSION

NAC appears to be an exciting option for management of surgically challenging cases of invasive OSSN and may be helpful in avoiding orbital exenteration. However, more studies are required to explore this treatment option.

Combining Brachytherapy and Cryotherapy as Adjuvant Therapy for Squamous Cell Carcinoma of the Conjunctiva: Literature Review and Case Reports

Background

Separately, cryotherapy and brachytherapy have shown promising results when adjuvating the excision of squamous cell carcinoma of the conjunctiva (SCCC). The aim of this paper is to assess the combined effect in terms of complications and recurrence rate.

Summary

We describe 2 patients suffering from SCCC, and we review the current literature on adjuvant cryotherapy and brachytherapy. Both patients, one of whom suffered from recurrent SCCC, underwent surgical excision followed by combined cryotherapy and brachytherapy. Cryotherapy was performed using a retinal cryoprobe, and 2 rounds each of 5 s with N₂O as a cryogen were applied. Brachytherapy was performed using a ruthenium-106 plaque, delivering a dosage of 100 Gy at 2-mm depth.

Key Messages

By reviewing the current literature and describing 2 case reports, this paper illustrates the use of combined cryotherapy and brachytherapy after surgical excision of SCCC. The current literature presents promising results of each treatment, and the 2 cases showed promising results by combining the 2 adjuvant therapies showing no signs of recurrence or complications during a follow-up period of 26 and 38 months.

Brachytherapy in India: Learning from the past and looking into the future

India has a longstanding tradition in the practice of brachytherapy and has actively contributed to the scientific literature by conducting prospective studies, clinical audits, developing innovative techniques, and performing randomized studies. Indian investigators have also contributed to international collaborative research, education, training programs along with guideline development for brachytherapy in cervix and head and neck cancers. The present article summarizes the key contributions to scientific literature, current infrastructure, skill set for brachytherapy, existing challenges, and strategy to further strengthen brachytherapy practice in the next decade.

Single-fraction low-energy electronic brachytherapy for conjunctival lymphoma

Purpose

Conjunctival lymphoma represents an uncommon tumor, accounting for 5-10% of total extranodal lymphomas. Although radiotherapy is a frequent treatment option, limited capacities and lack of specialized centers are common problems in Peru, forcing radiation oncologists to apply short courses of radiotherapy. Here, we report a case series of patients treated with a novel single-shot scheme. Additionally, we present a literature review of the current short-course irradiation strategies.

Cases presentation

Three cases of conjunctival marginal zone (B-cell) lymphoma (marginal zone lymphoma [MZL]/mucosa-associated lymphoid tissue [MALT]) of the fornix are presented. Following biopsy and sonographic assessment of the lesion thickness, we applied a focused single dose of 14 Gy kilovoltage brachytherapy (prescribed to the maximum thickness of the lesion). Follow-up was scheduled in quarterly intervals. After 28, 31, and 40 months of follow-up, none of the three patients treated exhibited acute or chronic toxicities and remained local or distant disease-free.

Conclusions

Single dose kilovoltage brachytherapy was effective and safe in this small cohort of patients. Based on the literature, there is an evidence that local treatment in short-course radiotherapy is effective and should be considered amongst therapeutic options for these patients; however, this novel approach should be evaluated prospectively in a larger cohort.

Management Issues in Conjunctival Tumours: Ocular Surface Squamous Neoplasia

Ocular surface squamous neoplasia is the most common tumour of the ocular surface. It is a spectrum of disease from intraepithelial dysplasia to invasive squamous cell carcinoma. Recent years have seen an increase in the use of topical chemotherapeutic agents to treat this condition, often as primary treatment without full-thickness biopsy. This practical approach provides a critical appraisal of the evidence base with the goal being to aid the clinician in the management of these patients.

Management of Invasive Squamous Cell Carcinomas of the Conjunctiva

PURPOSE

Ocular surface squamous neoplasia includes a spectrum of diseases from dysplasia to invasive squamous cell carcinoma (SCC) of the conjunctiva. Whether the degree of invasion influences outcomes is debated. We evaluated the outcomes and management of conjunctival carcinomas defined as ≤0.2 mm invasion of the chorion (microinvasive; miSCC) or over (SCC).

DESIGN

Retrospective case series.

METHODS

Clinical, tumor, and therapeutic characteristics and outcomes were collected for consecutive patients with histology-proven invasive conjunctival miSCC/SCC treated between 2002 and 2017.

RESULTS

Patients were 70% men, ≥70 years old (56%), with carcinomas of the bulbar conjunctiva (83.0%). Limbal, corneal, and/or scleral involvement were present in 70.4%, 42.6%, and 27.8%, respectively. Patient characteristics, tumor characteristics, and no-touch surgery rates were similar between the 39 SCC and 15 miSCC. However, mitomycin was performed in 93.3% and 20.5% of miSCC and SCC, respectively (P < .001). Proton therapy was performed in 0% and 92.0% of miSCC and SCC, respectively (P < .001). SCC received mitomycin in case of tumoral resection margins, respectively (P = .018). The 24-month incidence of local relapse was 14.8%, including 20% and 12% for miSCC and SCC, respectively (P = .079). Irradiation was the only prognostic factor associated with a lower risk for local relapse (hazard ratio [0.25]; P = .045). There were 2 cancer-related deaths (2%). Mild/moderate anterior segment complications occurred in one third of the patients.

CONCLUSIONS

miSCC had slightly worse relapse rates compared with SCC. Postoperative proton therapy, performed in SCC only, was associated with a lower risk for relapse.

Superficial radiotherapy as a treatment alternative for recurrent conjunctival squamous cell carcinoma: a case study

This case study discusses the use of superficial radiotherapy (SXRT) in the treatment of recurrent conjunctival squamous cell carcinoma (SCC). Conjunctival SCC is often an aggressive cancer, with surgery the current standard of care. There is currently limited literature on alternative treatment options to treat conjunctival SCC recurrences that enable ocular function preservation. Furthermore, the use of SXRT in this setting is not well-reported. Technical feasibility, practical limitations and potential side effects of SXRT (in comparison to other treatment options) are discussed in this case study. This case describes a 62 years old male with limited treatment options following multiple recurrences of conjunctival SCC. He was prescribed a therapeutic SXRT dose of 48.4 Gy in 22 fractions (5 fractions/week). At 6-month follow-up, there was no evidence of residual or recurrent disease, or any significant objective or patient reported treatment induced side effects. This case study provides preliminary evidence for the potential application of SXRT for conjunctival SCC. The benefits reported in this case study warrant further investigation of the applicability of SXRT in a larger patient cohort, with the potential to provide patients with a less invasive treatment alternative for recurrent conjunctival SCC.

Phase I/II study on kilovoltage surface brachytherapy in conjunctival cancer: preliminary results

INTRODUCTION

In ocular conjunctival carcinoma after surgery, adjuvant treatment has a role and kilovoltage surface brachytherapy opens a new door for the range of therapeutic options.

MATERIALS AND METHODS

Between October 2014 and June 2017, at the National Institute of Neoplastic Diseases (INEN) from Peru, 39 patients with squamous cell carcinoma of ocular conjunctiva, T1-T3, resected, were selected to receive adjuvant treatment. The portable accelerator of 50-kV INTRABEAM (Carl Zeiss Meditec) was used, after local anaesthesia and blocking of ocular muscles movement. The doses used were 18 Gy for patients with free margins and 22 Gy for positive edges, according to calculation of equivalent dose of 2Gy per fraction of 46 and 66 Gy, respectively, assuming a tumoural α/β ratio of 8 Gy. The prescription was done to 2 mm depth.

RESULTS

The median age was 69 years, distributed evenly between both genders, with a median follow-up of 12 months. The surgical margins were 59% free and 41% committed, with no difference between the institutions where the surgery was performed (P = 0.069). The median tumour size was 7 mm with 2 mm of invasion, 61.5% was T2 and 35.9% T1. The mean time between surgery and irradiation was 1.5 months, 23.1% of patients developed grade I toxicity of spontaneous resolution, without evidence of greater degree in any case. The dose had no statistical relationship with toxicity (P = 0.533). One-year disease-free survival was 96.7%.

CONCLUSIONS

Kilovoltage surface brachytherapy is an applicable and reproducible tool in the treatment of squamous cell carcinoma of ocular conjunctiva. The administered doses are well tolerated by patients with low levels of acute toxicity. Longer follow-up is needed to establish disease control rates and late toxicities.

[Adjuvant contact radiotherapy for conjunctival malignancies: Preliminary results of a series of 14 patients treated with the Papillon 50 machine]

PURPOSE

To evaluate the results of an adjuvant contact irradiation using 50kV photons after resection of conjunctival malignancies.

MATERIALS AND METHOD

From 2012 to 2014, 14 patients (male: nine; female: five) have been treated by contact irradiation after resection of a malignant tumor of the conjunctiva (melanoma: five patients; malignant fibrous histiocytoma: one patient; carcinoma: eight patients) The treatment was performed using the Papillon 50 machine (Ariane). Three to four sessions were delivered, each giving a dose of 10Gy. The median follow-up in survivors was 33 months.

RESULTS

The tolerance was good. A cataract was seen in one patient, and a moderate eye dryness in one. There was no corneal ulcer. One patient died of intercurrent disease. One patient with carcinoma recurred locally.

CONCLUSION

Adjuvant contact radiotherapy provides a good local control after resection of conjunctival malignancies (melanoma, malignant histiocytofibroma, carcinoma). Thanks to its precision, this technique is well tolerated with a low rate of complications. Furthermore, it is delivered on an ambulatory basis.