Late radiation failures after iodine 125 brachytherapy for uveal melanoma compared with charged-particle (proton or helium ion) therapy

External Beam Radiotherapy in the Management of Uveal Melanoma

OPINION STATEMENT

Uveal melanoma is the most common primary ocular tumor in adults. With the evidence demonstrating that episcleral plaque brachytherapy (EPB) has similar survival rates as enucleation in the Collaborative Ocular Melanoma Study (COMS), eye-sparing treatments have come to the fore today. External radiotherapy techniques (proton beam radiotherapy and stereotactic radiosurgery/fractionated stereotactic radiosurgery) are an important treatment option for globe-sparing treatments. There are no prospective randomized trials comparing these techniques; however, retrospective series, meta-analyses, and reviews indicate that these EPB and external radiotherapy techniques are equal. With this review, we aimed to examine the external radiotherapy techniques used in the treatment of uveal melanoma in detail with reference to the current literature.

Comparing efficacy of charged-particle therapy with brachytherapy in treatment of uveal melanoma

BACKGROUND

Uveal melanoma (UM) is the most common primary ocular tumour in adults. The most used eye-preserving treatments are charged-particle therapy (CPT) and brachytherapy. We performed a systematic review and meta-analysis to compare efficacies and complications of these two radiotherapies.

METHODS

We searched EMBASE, PubMed, MEDLINE, and the Cochrane Library from January 2012 to December 2022. Two independent reviewers identified controlled studies comparing outcomes of CPT versus brachytherapy. Case series that utilize either treatment modality were also reviewed.

RESULTS

One hundred fifty studies met the eligibility criteria, including 2 randomized control trials, 5 controlled cohort studies, and 143 case series studies. We found significant reduction in local recurrence rate among patients treated with CPT compared to brachytherapy (Odds ratio[OR] 0.38, 95% Confidence interval [CI] 0.24-0.60, p < 0.01). Analysis also showed a trend of increased risks of secondary glaucoma after CPT. No statistically significant differences were found in analyzing risks of mortality, enucleation, and cataract.

CONCLUSIONS

Our study suggested no difference in mortality, enucleation rate and cataract formation rate comparing the two treatments. Lower local recurrence rate and possibly higher secondary glaucoma incidence was noted among patients treated with CPT. Nevertheless, the overall level of evidence is limited, and further high-quality studies are necessary to provide a more definitive conclusion.

Gene Expression Profile Class Change in a Case of Aggressive, Recurrent Melanoma

Purpose: To report a novel case of a recurrent melanoma that had a change in its genetic expression profile (GEP) class over a 2-year period. Methods: This retrospective case study evaluated a patient with a recurrent uveal melanoma that changed classes from 1A to 1B. Results: A large melanoma was first treated with brachytherapy, and during that time genetic testing revealed a class 1A tumor. Two years later the tumor was noted to be enlarging, and the patient elected for enucleation. Subsequent GEP showed a class 1B tumor. Conclusions: An aggressive and large recurrent uveal melanoma that had changed from a class 1A to a class 1B tumor on subsequent GEP testing has never been reported before to our knowledge. It may imply that a recurrent or aggressive tumor has more mutations over time that could lead to a higher risk for metastasis. The natural course of a tumor's GEP class should be explored further.

Design and optimizing a novel ocular plaque brachytherapy with dual-core of 103Pd and 106Ru

In recent decades, eye plaques of brachytherapy have been extensively used as primary treatment as well as a complementary treatment for ocular cancer. The purpose of this study is the development of the eye plaque brachytherapy throughout a new design of eye plaque by combining the COMS plaque and the CCB BEBIG plaque loaded by IRA1-¹⁰³Pd and ¹⁰⁶Ru, respectively. A new dual-core plaque with a diameter of 20 mm was designed in the way that the BEBIG plaque with a diameter of 20 mm loaded by ¹⁰⁶Ru plate is attached to the COMS plaque with a diameter of 20 mm loaded by 24 of IRA1-¹⁰³Pd seeds. Dose calculations for the new plaque were performed by using the MCNP5 code. Dose calculations of dual-core plaque including ¹⁰³Pd seeds (gamma) and ¹⁰⁶Ru plate (beta) were separately done for the sake of MCNP constraints in gamma and beta particle transfer simultaneously. The new dual-core plaque delivers a much higher dose rate to the tumor compared with every single plaque, while the dose rate reached to healthy tissues is slightly higher than each plaque separately. Of course, this is acceptable because the treatment time reduces and subsequently the error in radiation therapy reduces.

Elevated VEGF-A & PLGF concentration in aqueous humor of patients with uveal melanoma following Iodine-125 plaque radiotherapy

AIM

To measure the concentration of vascular endothelial growth factor-A (VEGF-A), and placental growth factor (PLGF) in aqueous humor of uveal melanoma patients before and after Iodine-125 plaque therapy (IPT), determine the postoperative fluctuation and evaluate associated factors in vivo.

METHODS

Participants were 18 Chinese patients with uveal melanoma who were elected to IPT. Undiluted aqueous humor samples were collected at Iodine plaque implant and removal time, then stored immediately at -80°C until assayed. The concentration of VEGF-A, PLGF and other 7 cytokines comprising interleukin-2 (IL-2), IL-8, IL-10, interferon (IFN)-γ, programmed death (PD)-1, transforming growth factor (TGF)-β1 and insulin-like growth factor (IGF)-1 in aqueous humor was measured using Raybiotech immunoassay kit, a high throughput strategy. The VEGF-A and PLGF levels were compared across preoperation and postoperation subgroups, as well as those of other 7 interleukins. Correlation and grouped analyses were conducted to determine the independent effects of clinical parameters and other cytokines on VEGF-A and PLGF concentration or fluctuation. This study set a self-control design.

RESULTS

VEGF-A (P=0.038) and PLGF (P=0.026) were the only two increased cytokines after IPT. Preoperative and postoperative level of VEGF-A and PLGF (r=0.575, P=0.013; r=0.987, P<0.001) correlated with each other significantly. Level of VEGF-A (r=0.626, P=0.005; r=0.588, P=0.01) and PLGF (r=0.616, P=0.007; r=0.588, P=0.01) had positive correlation with tumor thickness consistently. Elevated VEGF-A or PLGF level were strong predictive factors of each other (P=0.007, OR=60.0). The elevated VEGF-A group showed a higher postoperative level of IFN-γ (P=0.005), IL-2 (P<0.001) and IL-10 (P=0.004) in aqueous humor. When the elevated PLGF group got similar results that a higher postoperative level of IFN-γ (P=0.007), IL-2 (P<0.001) and IL-10 (P=0.013) in aqueous humor.

CONCLUSION

This study reveals that VEGF-A and PLGF in aqueous humor significantly increased with tumor thickness and radiation process in uveal melanoma patients. VEGF-A and PLGF may be crucial in uveal melanoma genesis and radiotherapy reactions. Immune mediators comprised IFN-γ, IL-2 and IL-10 could play roles in the link between inflammation and angiogenesis in uveal melanoma when exposed to radiotherapy.

Precise delineation and tumor localization based on novel image registration strategy between optical coherence tomography and computed tomography in the radiotherapy of intraocular cancer

Radiation-associated toxicities due to sophisticated ocular anatomy and shape variability of organs at risk (OARs) are major concerns during external beam radiation therapy (EBRT) of patients with intraocular cancer. A novel two-step image registration strategy between optical coherence tomography (OCT) and computed tomography (CT) images was proposed and validated to precisely localize the target in the EBRT of patients with intraocular cancer. Specifically, multiple features from OCT and CT images were extracted automatically, then spatial transformation based on thin-plate spline function was performed iteratively to achieve feature alignment between the CT and OCT images. Finally, an exclusive OR (XOR) algorithm was applied for precise 3D registration using a 3D-mesh model generated from OCT and CT volumes. The accuracy of the proposed novel registration strategy was validated and tested in a schematic-eye phantom with an artificially introduced tumor and in ten patients with confirmed primary and/or secondary intraocular cancer. There was an average registration error and computational time of 0.21  ±  0.05° and 259  ±  5 s, together with an average Dice similarity coefficient and Hausdorff distance of 88.4  ±  0.65 and 0.89  ±  0.09, respectively. The preliminary experimental results demonstrated that the proposed novel strategy to overcome current limitations on eye modeling and to localize precisely the tumor target during EBRT of intraocular cancer is promising.

Late Apical Recurrence of Choroidal Melanoma 10 Years after Successful Treatment with Brachytherapy

PURPOSE

To describe late apical relapse of a choroidal melanoma at the site of fine needle aspiration biopsy 10 years following successful treatment with 125I brachytherapy.

METHODS

Retrospective case report of a 78-year-old male presenting 10 years following successful 125I brachytherapy for a choroidal melanoma with a medium-sized nodular amelanotic tumor recurrence at the site of the prior tumor biopsy.

RESULTS

Fundus photography and B-scan ultrasound documented the findings at presentation at our institution. The patient was followed closely for 8 weeks while information was retrieved from the treating institution. During this short period, there was significant apical tumor growth. Additionally, there was a clear clinical change compared to the last documented photos from 5 years prior at the treating institution. Enucleation was recommended. Pathological analysis confirmed the diagnosis of recurrent choroidal melanoma at the apex of the treated lesion, at the site of prior biopsy. Systemic surveillance was negative for metastatic disease.

CONCLUSION

Current literature suggests the majority of choroidal melanoma recurrences occur within 5 years following treatment. However, this case of recurrence 10 years after brachytherapy emphasizes the importance of life-long ophthalmic care for these patients. Additionally, this case demonstrates the possibility of a rare recurrence at a prior biopsy site.

Pattern of Local Recurrence After I-125 Episcleral Brachytherapy for Uveal Melanoma in a Spanish Referral Ocular Oncology Unit

PURPOSE

To describe the time, frequency, and clinical characteristics of treatment failure after I-125 brachytherapy in patients with uveal melanoma treated and followed in a Spanish referral ocular oncology unit.

DESIGN

Prospective, consecutive, interventional case series.

METHODS

Patients diagnosed with uveal melanoma from 1995 to 2016 and treated with episcleral brachytherapy were included. Demographic data collection, ophthalmic evaluation, ultrasound scan, and systemic studies were performed at baseline, every 6 months thereafter for 5 years, and subsequently at annual intervals. Recurrence was defined as presence of tumor growth after treatment. Baseline analysis was performed by descriptive methods and survival by Kaplan-Meier curves.

RESULTS

From 732 patients diagnosed with uveal melanoma, 311 were treated with brachytherapy. In the follow-up (mean 79 months, standard deviation = 55), 16 local tumor recurrences (5.1%) were detected. All relapsing patients had choroidal tumors and 15 presented with visual symptoms. All patients were treated with I-125 brachytherapy, and 2 received associated transpupillary thermotherapy. All the eyes were enucleated after recurrence. Kaplan-Meier analysis showed a mean time of recurrence of 3.7 years (standard deviation = 2.94 years, ranging from 1 to 12 years). Three patients had metastasis in the follow-up. Kaplan-Meier analysis showed worse survival for patients with recurrence.

CONCLUSION

Local treatment failure was a relatively infrequent event after I-125 brachytherapy in our series. Recurrences appear not only early but also late in the follow-up. They do not have a distinctive clinical pattern and are associated with poorer survival.

Dosimetric advantage of volumetric modulated arc therapy in the treatment of intraocular cancer

Objective

The purpose of this study is to investigate the dosimetric advantages of volumetric modulated arc therapy (VMAT) in the treatment of intraocular cancer by comparing it directly with three-dimensional conformal radiotherapy (CRT) and intensity-modulated radiotherapy (IMRT).

Methods

CRT plan, 7f-IMRT plan, and one-arc VMAT plan were generated for 14 intraocular cancer patients. Dosimetric and biological quality indices for target volume and organs at risks (OARs) were evaluated and compared.

Results

The target coverage presented by V95 for CRT, IMRT and VMAT were 95.02% ± 0.67%, 95.51% ± 2.25%, and 95.92% ± 3.05%, respectively. The homogeneity index (HI) for CRT, IMRT and VMAT were 0.15 ± 0.05, 0.23 ± 0.05, and 0.23 ± 0.06, respectively. IMRT and VMAT greatly decreased the dose to ipsilateral lens compared with CRT with a D1 of 2972.66 ± 1407.12 cGy, 3317.82 ± 915.28 cGy and 4809.54 ± 524.60 cGy for IMRT, VMAT and CRT, respectively. Similar results were observed for ipsilateral eyeballs. IMRT and VMAT also spared better on brainstem, optical nerves and optical chiasm compared CRT. However, CRT achieved lower dose to the eyeballs compared with IMRT and VMAT. VMAT and IMRT showed mixed results on target coverage and OAR sparing. The average MUs and delivery time of IMRT and VMAT were 531.25 ± 81.21 vs. 400.99 ± 61.49 and 5.05 ± 0.53 vs.1.71 ± 0.69 min, respectively.

Conclusions

Although no clear distinction on PTV coverage among CRT, IMRT and VMAT plans was observed in the treatment of intraocular cancer, VMAT and IMRT achieved better homogeneity and conformity for target volume, and delivered fewer doses to ipsilateral lens and eyeballs compared with CRT. However, VMAT and IMRT increased the low dose volume to the contralateral OARs. Although VMAT and IMRT showed mixed results on target coverage and OAR sparing, VMAT decreased MU and delivery time significantly compared with IMRT. VMAT is a promising and feasible external beam radiotherapy technique in the treatment of intraocular cancer patients.

Local Failure After Episcleral Brachytherapy for Posterior Uveal Melanoma: Patterns, Risk Factors, and Management

PURPOSE

To evaluate the patterns, the risk factors, and the management of recurrence following brachytherapy in patients with posterior uveal melanoma, given that an understanding of the recurrence patterns can improve early recognition and management of local treatment failure in such patients.

DESIGN

Retrospective cohort study.

METHODS

Setting: Multispecialty tertiary care center.

PARTICIPANTS

A total of 375 eyes treated with episcleral brachytherapy for posterior uveal melanoma from January 2004 to December 2014. Exclusion criteria included inadequate follow-up (<1 year) and previous radiation therapy. Main Outcomes and Measures: Local control rate and time to recurrence were the primary endpoints. Kaplan-Meier estimation and Cox proportional hazards models were conducted to identify risk factors for recurrence.

RESULTS

Twenty-one patients (5.6%) experienced recurrence (follow-up range 12-156 months; median 47 months). The median time to recurrence was 18 months (range 4-156 months). Five-year estimated local recurrence rate was 6.6%. The majority (90.5%) of the recurrences occurred within the first 5 years. The predominant site of recurrence was at the tumor margin (12 patients, 57.1%). Univariate analysis identified 3 statistically significant recurrence risk factors: advanced age, largest basal diameter, and the use of adjuvant transpupillary thermotherapy (TTT). Recurrent tumors were managed by repeat brachytherapy, TTT, or enucleation.

CONCLUSIONS

Local recurrences following brachytherapy are uncommon 5 years after episcleral brachytherapy. Follow-up intervals can be adjusted to reflect time to recurrence. Most of the eyes with recurrent tumor can be salvaged by conservative methods.

Local Recurrence Significantly Increases the Risk of Metastatic Uveal Melanoma

PURPOSE

To assess of the effect of local recurrence of uveal melanoma on metastasis using a multicenter international tumor registry.

DESIGN

Retrospective study using an online tumor registry.

PARTICIPANTS

Patients with uveal melanoma diagnosed between 2001 and 2011.

METHODS

A committee was formed to create uveal melanoma patient-specific data fields. Ten subspecialty ophthalmic oncology centers from 4 continents shared data. Patient selection criteria included diagnosis of uveal melanoma and adequate records to allow tumor staging by American Joint Committee on Cancer (AJCC) criteria and follow-up for metastatic melanoma.

MAIN OUTCOME MEASURES

Local tumor recurrence and metastatic uveal melanoma.

RESULTS

Of 3809 total entries, 3217 patients with ciliary body and choroidal (CBC) melanoma and 160 with iris melanoma were evaluated. There was a median follow-up of 3.7 years (95% confidence interval [CI], 3.5-3.8). One hundred fifty-two patients (4.7%) with CBC melanoma experienced local recurrence, with a cumulative incidence of 11%. Kaplan-Meier point estimates for remaining free of local recurrence were 99% (95% CI, 99-99) at 1 year, 93% (95% CI, 92-94) at 5 years, and 89% (95% CI, 86-91) at 10 years. Five- and 10-year metastasis-free Kaplan-Meier estimates for the recurrence-free group were 87% (95% CI, 86-89) and 82% (95% CI, 79-84), and those for the local recurrence group were 71% (95% CI, 62-78) and 62% (95% CI, 49-72). The difference between these 2 groups was statistically significant (P < 0.001). Furthermore, local tumor recurrence increased the risk of metastasis by a hazard ratio (HR) of 6.28 (95% CI, 4.4-8.9; P < 0.001). Local recurrence was detected up to 9.8 years after treatment. Extrascleral extension also was associated with local recurrence (HR, 3.2; 95% CI, 1.5-6.7; P = 0.003), but higher AJCC T-size category was not (P = 0.63). Five patients (n = 5/161 [3.1%]) with iris melanoma demonstrated local recurrence and 1 metastasized.

CONCLUSIONS

International multicenter data sharing was used to evaluate the effect of local tumor recurrence on metastatic rate. In that local tumor recurrence was associated with a significantly higher risk of systemic metastasis, effective initial treatment and long-term surveillance of treated uveal melanoma patients is necessary.

Outcomes and control rates for I-125 plaque brachytherapy for uveal melanoma: a community-based institutional experience

Purpose. To evaluate our community-based institutional experience with plaque brachytherapy for uveal melanomas with a focus on local control rates, factors impacting disease progression, and dosimetric parameters impacting treatment toxicity. Methods and Materials. Our institution was retrospectively reviewed from 1996 to 2011; all patients who underwent plaque brachytherapy for uveal melanoma were included. Follow-up data were collected regarding local control, distant metastases, and side effects from treatment. Analysis was performed on factors impacting treatment outcomes and treatment toxicity. Results. A total of 107 patients underwent plaque brachytherapy, of which 88 had follow-up data available. Local control at 10 years was 94%. Freedom from progression (FFP) and overall survival at 10 years were 83% and 79%, respectively. On univariate analysis, there were no tumor or dosimetric treatment characteristics that were found to have a prognostic impact on FFP. Brachytherapy treatment was well tolerated, with clinically useful vision (>20/200) maintained in 64% of patients. Statistically significant dosimetric relationships were established with cataract, glaucoma, and retinopathy development (greatest P = 0.05). Conclusions. Treatment with plaque brachytherapy demonstrates excellent outcomes in a community-based setting. It is well tolerated and should remain a standard of care for COMS medium sized tumors.

Disease control and toxicity outcomes using ruthenium eye plaque brachytherapy in the treatment of uveal melanoma

PURPOSE

Ruthenium-106 ((106)Ru) eye plaques have the potential to achieve excellent tumor control with acceptable radiation toxicity. We evaluated our experience in the management of uveal melanoma treated with (106)Ru brachytherapy.

METHODS AND MATERIALS

The records of 40 patients with uveal melanoma treated with brachytherapy using (106)Ru plaques from 2003 to 2007 at University of Texas MD Anderson Cancer Center were reviewed. Endpoints assessed included tumor control and toxicity.

RESULTS

Median ophthalmologic follow-up was 67 months. Actuarial 5-year rates of local control (LC), progression-free survival (PFS), and overall survival (OS) were 97%, 94%, and 92%. There were 3 deaths, 2 related to melanoma. Fifteen patients experienced clinically significant visual loss; no patients were diagnosed with neovascular glaucoma, and 1 patient developed a clinically significant radiation-associated cataract. No patient required enucleation.

CONCLUSIONS

We report the largest published US cohort of patients treated with (106)Ru plaque brachytherapy for uveal melanoma. Tumor control was excellent, and toxicity was acceptably low. These data support the reintroduction of (106)Ru into clinical practice for ocular melanoma.

Radiation-induced equilibrium is a balance between tumor cell proliferation and T cell-mediated killing

Local failures following radiation therapy are multifactorial, and the contributions of the tumor and the host are complex. Current models of tumor equilibrium suggest that a balance exists between cell birth and cell death due to insufficient angiogenesis, immune effects, or intrinsic cellular factors. We investigated whether host immune responses contribute to radiation-induced tumor equilibrium in animal models. We report an essential role for immune cells and their cytokines in suppressing tumor cell regrowth in two experimental animal model systems. Depletion of T cells or neutralization of IFN-γ reversed radiation-induced equilibrium, leading to tumor regrowth. We also demonstrate that PD-L1 blockade augments T cell responses, leading to rejection of tumors in radiation-induced equilibrium. We identify an active interplay between tumor cells and immune cells that occurs in radiation-induced tumor equilibrium and suggest a potential role for disruption of the PD-L1/PD-1 axis in increasing local tumor control.

Expression of 12 cytokines in aqueous humour of uveal melanoma before and after combined Ruthenium-106 brachytherapy and transpupillary thermotherapy

PURPOSE

To determine the aqueous humour levels of 12 cytokines in eyes with uveal melanoma and whether their expression changes after combined Ru-106 brachytherapy and transpupillary thermotherapy (TTT).

METHODS

Aqueous humour samples were collected from 20 patients with previously untreated uveal melanoma undergoing combined Ru-106 brachytherapy and TTT, both at the time of plaque placement and removal. Using multiplex biochip array technology, 12 different cytokines were measured, including interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, vascular endothelial growth factor (VEGF), tumour necrosis factor (TNF)-α, interferon (IFN)-γ, epidermal growth factor (EGF) and monocyte chemoattractant protein (MCP)-1. Aqueous humour from 20 patients undergoing cataract surgery was used as control.

RESULTS

IL-6, IL-8, IFN-γ and MCP-1 were highly expressed in uveal melanoma, whereas IL-2, IL-10 and TNF- α were low in expression. There was a positive correlation between tumour height and IL-8 level (p = 0.020). Vascular endothelial growth factor tends to be highly expressed in melanoma-containing eyes (p = 0.056). Levels of IL-6, IL-8 and IL-1β increased after the mean 117 ± 38 hrs of brachytherapy and adjunctive TTT with a tumour apex dose of 61 ± 28 Gy and a scleral contact dose of 786 ± 226 Gy. Increase in levels of IL-6 (p = 0.003) and IL-8 (p = 0.046) positively correlated with scleral contact dose.

CONCLUSIONS

Cytokines such as IL-6, IL-8, IFN-γ and MCP-1 may be implicated in the progression of uveal melanoma. Ocular irradiation from a Ru-106 plaque promoted an increase in the levels of IL-6, IL-8 and IL-1β, modulation of which could be useful in managing radiation-related side effects.

Optical eye tracking system for noninvasive and automatic monitoring of eye position and movements in radiotherapy treatments of ocular tumors

A noninvasive eye tracking system based on infrared 3-D video-oculographic techniques is proposed for the automatic monitoring of eye position and orientation in external beam radiotherapy of ocular tumors. The presented method can be applied for the real-time estimation of lesion position and tumor-beam misalignments, allowing automatic patient setup and eye movement gated treatments. A prototypal eye tracker was developed and tested on five subjects, achieving gaze estimation errors of 0.5° and eye monitoring frequencies of 125 Hz. The proposed application can potentially improve quality and efficacy of ocular radiotherapy treatments, currently based on invasive, qualitative, and manual control procedures.

Visual outcome, local tumour control, and eye preservation after 106Ru/Rh brachytherapy for choroidal melanoma

To study the visual outcome, local tumour control, and eye preservation 5 years after ruthenium/rhodium 106 brachytherapy for choroidal melanoma. The study included 55 consecutive patients treated by 106Ru/Rh brachytherapy for a choroidal melanoma during the period 1988-2000 and followed through 2004. The 5-year probability for not losing at least 5 Snellen lines was 59% (n = 45), for retaining a visual acuity of 0.33 or better was 28% (n = 34), and for retaining better than 0.1 was 40% (n = 45). The 5-year probability for no local recurrence was 73% and for eye preservation 72% (n = 55). 106Ru/Rh brachytherapy for choroidal melanoma resulted in a clinically significant vision loss, no local recurrence, and eye preservation in most patients after 5 years. 106Ru/Rh brachytherapy can be regarded as a good treatment option for small and medium-sized tumours but not for large tumours.

The effectiveness and safety of proton radiation therapy for indications of the eye : a systematic review

BACKGROUND AND PURPOSE

: Proton radiation has been used for the treatment of uveal melanoma since 1975, but few studies have been conducted to assess its efficacy and safety. This paper aims to systematically review the effects and side effects of proton therapy for any indication of the eye.

MATERIAL AND METHODS

: A range of databases were searched from inception to 2007. All studies that included at least ten patients and that assessed the efficacy or safety of proton therapy for any indication of the eye were included.

RESULTS

: The search generated 2,385 references, of which 37 met the inclusion criteria. Five controlled trials, two comparative studies and 30 case series were found, most often reporting on uveal melanoma, choroidal melanoma and age-related macular degeneration (AMD). Methodological quality of these studies was poor. Studies were characterized by large differences in radiation techniques applied within the studies, and by variation in patient characteristics within and between studies. Results for uveal melanoma and choroidal melanoma suggest favorable survival, with, however, significant rates of side effects. Results for choroidal hemangioma and AMD did not reveal beneficial effects from proton radiation.

CONCLUSION

: There is limited evidence on the effectiveness and safety of proton radiation due to the lack of well-designed and well-reported studies. There is a need to lift evidence on proton therapy to a higher level by performing dose-finding randomized controlled trials (RCTs), comparative studies of proton radiation versus standard given alternatives and prospective case studies enrolling only patients treated with up-to-date techniques, allowing extrapolation of results to similar patient groups.

A systematic literature review of the clinical and cost-effectiveness of hadron therapy in cancer

BACKGROUND

In view of the continued increase in the number of hadron (i.e. neutron, proton and light or heavy ion) therapy (HT) centres we performed a systematic literature review to identify reports of the efficacy of HT.

METHODS

Eleven databases were searched systematically. No limit was applied to language or study design. Established experts were contacted for unpublished data. Data on outcomes were extracted and summarised in tabular form.

RESULTS

Seven hundred and seventy three papers were identified. For proton and heavy ion therapy, the number of RCTs was too small to draw firm conclusions. Based on prospective and retrospective studies, proton irradiation emerges as the treatment of choice for some ocular and skull base tumours. For prostate cancer, the results were comparable with those from the best photon therapy series. Heavy ion therapy is still in an experimental phase.

CONCLUSION

Existing data do not suggest that the rapid expansion of HT as a major treatment modality would be appropriate. Further research into the clinical and cost-effectiveness of HT is needed. The formation of a European Hadron Therapy Register would offer a straightforward way of accelerating the rate at which we obtain high-quality evidence that could be used in assessing the role of HT in the management of cancer.

Finger's "slotted" eye plaque for radiation therapy: treatment of juxtapapillary and circumpapillary intraocular tumours

AIM

To create "slotted eye plaques" for the treatment of juxtapapillary and circumpapillary intraocular tumours.

METHODS

Eye plaques were altered such that 8 mm-wide slots (variable length) were created to accommodate the orbital portion of the optic nerve. Thus, as the nerve entered the slot, the plaque's posterior margin extended beyond the optic disc. Radioactive seeds were affixed around the slot, surrounding the juxtapapillary and posterior tumour margins.

RESULTS

As proof of principle, three patients with choroidal melanomas that encircled or were in contact with the optic disc (considered untreatable with a notched eye plaque) were considered to be initial candidates for slotted-plaque radiotherapy. Preoperative three-dimensional C-scan imaging of their optic nerve sheath diameters insured that they would fit in the slotted plaque. Intraoperative ultrasound imaging was used to confirm proper plaque placement. Radiation dosimetry modelling showed that all tumour tissue received a minimum of 85 Gy (despite the gap created by the slot). With relatively short-term follow-up, there has been no evidence of ocular ischaemia, tumour growth or complications attributable to the use of slotted-plaque radiation therapy.

CONCLUSION

Slotted plaques accommodate the retrobulbar optic nerve into the device and thereby shift the treatment zone to improve coverage of both juxtapapillary and circumpapillary intraocular tumours.

18 years' experience with high dose rate strontium-90 brachytherapy of small to medium sized posterior uveal melanoma

AIM

To analyse local tumour control, radiation related complications, visual acuity, enucleation rate, and survival after brachytherapy of small to medium sized choroidal melanoma (CM) with a high dose rate (HDR) strontium-90 (Sr-90) applicator.

METHODS

From 1983 until 2000, 98 eyes with CM were treated with Sr-90 brachytherapy. The main outcome measures were actuarial rates of the patients' survival, ocular conservation rate, tumour regression, complication rates, and preservation of visual acuity. End point rates were estimated using Kaplan-Meier analysis.

RESULTS

The median follow up time was 6.7 years (0.5-18.8 years). Actuarial melanoma free patient survival rate was 85% (SE 4.8%) after 18 years. Actuarial rate of ocular conservation and complete tumour regression was 90% (SE 3.8%) after 15 years. In 93% local tumour control was achieved, 88% showed a stable scar. Recurrence of the tumour on the border caused enucleation of six eyes (7%). In three cases (4%) retinal detachment was the end point. No cases of optic atrophy or of sight impairing retinopathy outside the treated area were found. Actuarial rate of preservation of visual acuity of 1/10 was 65% at 5 years and 45% at 15 years of follow up (SE 5.9% and 8.8%).

CONCLUSIONS

Sr-90 brachytherapy is as effective as iodine or ruthenium brachytherapy for small to medium sized CM but causes fewer complications. The preservation of vision is better than with all other described radioisotopes. HDR Sr-90 brachytherapy can therefore safely be recommended for small to medium sized CM.

Radiation complications and tumor control after 125I plaque brachytherapy for ocular melanoma

PURPOSE

To determine the outcome of 125I plaque brachytherapy at our institution and identify the risk factors associated with the development of radiation complications, tumor recurrence, and metastasis.

PATIENTS AND METHODS

From 1986 to 2000, 156 patients underwent 125I episcleral plaque (COMS design) application for the treatment of ocular melanoma. Chart analysis of follow-up ophthalmologic appointments assessed the incidence of ocular side effects after therapy. Statistical analysis assessed outcomes and significant influencing factors.

RESULTS

With a median follow-up of 6.2 years, the 5-year overall survival was 83%. The 5-year disease-specific survival was 91%. Initial local control at 5 years was 92%, with 100% ultimate local control after secondary therapy that included 9 enucleations. The risk of metastasis was 10% at 5 years and 27% at 10 years. Vision stayed the same or improved in 25% of patients, and 44% of patients maintained visual acuity better than 20/200. Thirteen percent of patients experienced chronic pain or discomfort in the treated eye. Dose rates to the tumor apex greater than 90 to 100 cGy/h were associated with increased systemic control but worse radiation toxicity.

CONCLUSION

Patients in our series experienced excellent local tumor control. Higher dose rates to the tumor apex were associated with reduced rates of distant metastases but worse ocular function.