Conservation treatment of the eye: Conformal proton reirradiation for recurrent uveal melanoma

Re-treatment of locally recurrent uveal melanoma with repeat eye plaque I-125 brachytherapy: A single institution experience

PURPOSE

Eye plaque brachytherapy (EPBT) is the most common treatment for uveal melanoma with high local control rates of 95-100%. When local recurrences occur following EPBT, salvage options include enucleation, transpupillary thermotherapy (TTT), external beam radiation, or re-irradiation with EPBT. The purpose of this study is to report our institution's experience with EPBT re-irradiation for locally recurrent uveal melanoma.

METHODS AND MATERIALS

Patients were included if they were previously treated for uveal melanoma with EPBT, experienced local recurrence, and were subsequently treated at our institution with EPBT from 2016- 2020.

RESULTS

A total of 5 patients with median age 68 years were included. All patients were initially treated at an outside institution (OSI) with Iodine-125 or Ruthenium-106 EPBT. Mean time between EPBT at the OSI and EPBT at our facility was 130 months (range 28-231 months). Patients were re-irradiated with Iodine-125 EPBT prescribed to 85 Gy over 168 hours. Median follow up after re-treatment at our center was 24 months. Local control among this cohort was 100%. Metastasis occurred in two patients after re-treatment, at 8 months and 7 months. At last follow up, all treated lesions were decreased in size. Four patients experienced worsening visual acuity. Four patients developed cataracts, while two patients developed radiation retinopathy with cystoid macular edema requiring anti-VEGF injections. One patient developed radiation retinopathy but did not require injections. No patients required enucleation.

CONCLUSIONS

Re-treatment of locally recurrent uveal melanomas with EPBT is a feasible alternative to enucleation with a high local control rate. Ocular toxicities have not been significant enough to require enucleation.

Dosimetric comparison and secondary malignancy risk estimation for linac-based and robotic stereotactic radiotherapy in uveal melanoma

It was aimed to investigate the dosimetric differences among linac-based and robotic stereotactic radiotherapy (SRT) techniques for the treatment of uveal melanoma and to evaluate secondary malignancy risks for these different SRT techniques. Ten patients who received robotic SRT with CyberKnife were retrospectively included in this study. A total dose of 54 Gy in three fractions was prescribed to the planning target volume (PTV). For each patient, non-coplanar micro-multileaf collimator based dynamic conformal arc (DCA), intensity-modulated radiotherapy (IMRT) and circular cone based DCA (cDCA) plans were generated. During the analysis dose-volume histogram (DVH) parameters, homogeneity index, new conformity index, the volume received more than or equal to 30% and 50% of the prescribed dose were compared. Additionally, secondary malignancy risk for each technique was estimated using the risk factors recommended by The International Commission on Radiological Protection. Robotic SRT plans provided a high degree of conformity within the PTV and better normal tissue sparing compared to linac-based treatment plans. However, dose distribution was more heterogeneous in robotic SRT plans than that in linac-based techniques. Estimated secondary malignancy risk was also found as 3.4%, 1.4%, 1.4% and 1.6% for robotic SRT and linac-based IMRT, DCA, cDCA plans, respectively. Treatment parameters of uveal melanoma patients planned with robotic SRT had superior conformity and organ-at-risk (OAR) sparing compared with those planned with the linac-based system. However, estimated secondary malignancy risk was almost two-times higher in robotic SRT than that in linac-based techniques.

Dosimetric comparison of protons vs photons in re-irradiation of intracranial meningioma

OBJECTIVES

Re-irradiation of recurrent intracranial meningiomas represents a major challenge due to dose limits of critical structures and the necessity of sufficient dose coverage of the recurrent tumor for local control. The aim of this study was to investigate dosimetric differences between pencil beam scanning protons (PBS) and volumetric modulated arc therapy (VMAT) photons for intracranial re-irradiation of meningiomas.

METHODS

Nine patients who received an initial dose >50 Gy for intracranial meningioma and who were re-irradiated for recurrence were selected for plan comparison. A volumetric modulated arc therapy photon and a pencil beam scanning proton plan were generated (prescription dose: 15 × 3 Gy) based on the targets used in the re-irradiation treatment.

RESULTS

In all cases, where the cumulative dose exceeded 100 or 90 Gy, these high dose volumes were larger for the proton plans. The integral doses were significantly higher in all photon plans (reduction with protons: 48.6%, p < 0.01). In two cases (22.2%), organ at risk (OAR) sparing was superior with the proton plan. In one case (11.1%), the photon plan showed a dosimetric advantage. In the remaining six cases (66.7%), we found no clinically relevant differences in dose to the OARs.

CONCLUSIONS

The dosimetric results of the accumulated dose for a re-irradiation with protons and with photons were very similar. The photon plans had a steeper dose falloff directly outside the target and were superior in minimizing the high dose volumes. The proton plans achieved a lower integral dose. Clinically relevant OAR sparing was extremely case specific. The optimal treatment modality should be assessed individually.

ADVANCES IN KNOWLEDGE

Dose sparing in re-irradiation of intracranial meningiomas with protons or photons is highly case specific and the optimal treatment modality needs to be assessed on an individual basis.

Personalized re-treatment strategy for uveal melanoma local recurrences after interventional radiotherapy (brachytherapy): single institution experience and systematic literature review

Purpose

To report the results of a patient’s tailored therapeutic approach using a second course of interventional radiotherapy (brachytherapy) in patients with locally recurrent uveal melanoma.

Material and methods

Patients who had already undergone ocular brachytherapy treated at our IOC (Interventional Oncology Center) were considered. Five patients who has received a second course of treatment with a plaque after local recurrences were included in our study. Re-irradiation was performed with Ruthenium-106 (prescribed dose to the apex 100 Gy) or with Iodine-125 plaques (prescribed dose to the apex 85 Gy). Moreover, a systematic literature search was conducted through three electronic databases, including Medline/PubMed, Scopus, and Embase.

Results

All patients were initially treated with Ruthenium-106 plaque; the re-irradiation was performed with Ruthenium-106 plaque in three cases and with Iodine in two cases. Mean time between the first and the second plaque was 56.8 months (range, 25-93 months). Local tumor control rate was 100%, no patient underwent secondary enucleation owing to re-treatment failure. Distant metastasis occurred in 1 patient after 6 months from re-treatment. After a median follow-up of 44.2 months (range, 26-65 months) from re-treatment, all patients experienced worsening of the visual acuity (median visual acuity was 0.42 at time of recurrence and decline to 0.24 at the most recent follow-up); cataract occurred in two cases, no patient developed scleral necrosis. We considered 2 papers for a systematic review.

Conclusions

In selected cases, especially in presence of marginal local recurrence, a personalized re-treatment strategy with a plaque may offer high probability of tumor control and organ preservation but worsening of visual acuity.

Repeat Episcleral Plaque Brachytherapy: Clinical Outcomes in Patients Treated for Locally Recurrent Posterior Uveal Melanoma

PURPOSE

To report the outcomes of survival, local control, visual acuity, and eye retention in patients treated with repeat episcleral plaque brachytherapy (EPBT) for locally recurrent posterior uveal melanoma (PUM).

DESIGN

Retrospective, interventional case series.

METHODS

Setting: Institutional.

PATIENT POPULATION

A total of 1201 patients that underwent iodine-125 (I-125) EPBT as primary treatment for PUM between 1985 and 2015.

INCLUSION CRITERIA

Development of locally recurrent disease and retreatment with I-125 EPBT.

OBSERVATION PROCEDURES

Clinical records review.

MAIN OUTCOME MEASURES

Visual acuity, Kaplan-Meier estimates of survival, local control, metastasis, and loss of the eye over the duration of follow-up.

RESULTS

Twenty-seven patients (13 men) met our inclusion criteria. Median (range) follow-up from initial treatment was 100 months (14-365 months), while median time to local recurrence was 43 months (9-185 months). Median (range) follow-up after retreatment was 47 months (3-120 months). Kaplan-Meier estimate for local control at 5 years was 77.2% (95% confidence interval [CI], 53.29%-89.91%). All marginal recurrences were successfully retreated whereas 6 of 15 patients with central recurrence developed subsequent re-recurrence following salvage EPBT. Median (range) visual acuity was 20/70 (20/20 to counting fingers at 1 foot) at time of recurrence and declined to counting fingers (20/25 to hand motion) at the most recent follow-up examination. Kaplan-Meier estimate for absence of metastatic disease at 5 years was 78.5% (95% CI, 54.77%-90.70%).

CONCLUSIONS

Repeat I-125 EPBT offers a viable alternative to enucleation in patients with local recurrence of PUM, yielding high rates of local control with predictable decline in visual acuity.

Reirradiation of Recurrent and Second Primary Head and Neck Cancer With Proton Therapy

PURPOSE

To report the clinical outcomes of head and neck reirradiation with proton therapy.

METHODS AND MATERIALS

From 2004 to 2014, 61 patients received curative-intent proton reirradiation, primarily for disease involving skull base structures, at a median of 23 months from the most recent previous course of radiation. Most had squamous cell (52.5%) or adenoid cystic (16.4%) carcinoma. Salvage surgery before reirradiation was undertaken in 47.5%. Gross residual disease was present in 70.5%. For patients with microscopic residual disease, the median dose of reirradiation was 66 Gy (relative biological effectiveness), and for gross disease was 70.2 Gy (relative biological effectiveness). Concurrent chemotherapy was given in 27.9%.

RESULTS

The median follow-up time was 15.2 months and was 28.7 months for patients remaining alive. The 2-year overall survival estimate was 32.7%, and the median overall survival was 16.5 months. The 2-year cumulative incidence of local failure with death as a competing risk was 19.7%; regional nodal failure, 3.3%; and distant metastases, 38.3%. On multivariable analysis, Karnofsky performance status ≤70%, the presence of a gastrostomy tube before reirradiation, and an increasing number of previous courses of radiation therapy were associated with a greater hazard ratio for death. A cutaneous primary tumor, gross residual disease, increasing gross tumor volume, and a lower radiation dose were associated with a greater hazard ratio for local failure. Grade ≥3 toxicities were seen in 14.7% acutely and 24.6% in the late setting, including 3 treatment-related deaths.

CONCLUSIONS

Reirradiation with proton therapy, with or without chemotherapy, provided reasonable locoregional disease control, toxicity profiles, and survival outcomes for an advanced-stage and heavily pretreated population. Additional data are needed to identify which patients are most likely to benefit from aggressive efforts to achieve local disease control and to evaluate the potential benefit of proton therapy relative to other modalities of reirradiation.

Role of radiation therapy in melanomas: Systematic review and best practice in 2016

Radiotherapy has been used for skin cancers since early after the discovery of X-rays. The introduction of sophisticated surgery techniques and information of the general population on potential late radiation-induced toxicity and carcinogenesis have led to limiting indications in the dermatologist community. However, radiotherapy (RT) has undergone considerable developments, essentially including technological advances, to sculpt radiation delivery, with demonstration of the benefit either alone or after adding concomitant cytotoxic agents or targeted therapies. Although side effects due to high doses and/or the use of old RT techniques have been significantly decreased, the risk of atrophic scars, ulcerations or secondary cancers persist. In this systematic review, we aim to discuss indications for RT in melanomas with focus on new advances that may lead to rehabilitating this treatment option according to the tumor radiosensitivity and clinical benefit/risk ratio. Melanomas have been considered as radioresistant tumors for many years.

Local Recurrence After Primary Proton Beam Therapy in Uveal Melanoma: Risk Factors, Retreatment Approaches, and Outcome

PURPOSE

To evaluate the risk factors, recurrence rates, retreatments, and long-term patient outcomes following proton beam therapy for uveal melanoma.

DESIGN

Retrospective interventional case series.

METHODS

All patients treated with primary proton beam therapy for uveal melanoma at the oncology service at Charité-Berlin and Helmholtz-Zentrum-Berlin between May 1998 and December 2008 were reviewed for local recurrence. Of 982 patients, 982 eyes matched the inclusion criteria. The data were obtained from electronic health records, operative reports, discharge letters, and radiation planning. Comparisons of fundus photographs and ultrasound measurements were performed to assess the growth pattern of the tumor and to determine the success of retreatment, in the case that a globe-retaining therapy was undertaken.

RESULTS

Of 982 patients, 35 patients (3.6%) developed local recurrence. The median follow-up was 60.7 months (6.0-170.4 months). Local control rate was 96.4% and the overall eye retention rate was 95.0% in this cohort. Local recurrence was correlated with a higher risk for metastasis and reduced survival. Largest tumor diameter was identified as the sole statistically significant risk factor for local recurrence (P = .00001). All globe-retaining retreatment approaches for local recurrence, including proton beam therapy, brachytherapy, and transpupillary thermotherapy used for recurrences at the tumor margins, showed good local tumor control and similar metastasis-free survivals.

CONCLUSIONS

This study showed that each globe-retaining retreatment approach can result in satisfying local tumor control. In case of early detection of local recurrence, preservation of the globe can be warranted. Therefore, regularly performed follow-ups should be ensured.

Proton radiobiology

In addition to the physical advantages (Bragg peak), the use of charged particles in cancer therapy can be associated with distinct biological effects compared to X-rays. While heavy ions (densely ionizing radiation) are known to have an energy- and charge-dependent increased Relative Biological Effectiveness (RBE), protons should not be very different from sparsely ionizing photons. A slightly increased biological effectiveness is taken into account in proton treatment planning by assuming a fixed RBE of 1.1 for the whole radiation field. However, data emerging from recent studies suggest that, for several end points of clinical relevance, the biological response is differentially modulated by protons compared to photons. In parallel, research in the field of medical physics highlighted how variations in RBE that are currently neglected might actually result in deposition of significant doses in healthy organs. This seems to be relevant in particular for normal tissues in the entrance region and for organs at risk close behind the tumor. All these aspects will be considered and discussed in this review, highlighting how a re-discussion of the role of a variable RBE in proton therapy might be well-timed.

Salvage proton beam therapy in local recurrent uveal melanoma

PURPOSE

To evaluate survival and ocular outcome in recurrent uveal melanoma treated with proton beam therapy as salvage therapy.

DESIGN

Retrospective, interventional case series.

METHODS

We evaluated 48 patients with local recurrence of uveal melanoma after primary treatment with brachytherapy, transpupillary thermotherapy, proton beam therapy, laser photocoagulation, CyberKnife radiation, or photodynamic therapy. All patients received proton beam therapy as a salvage therapy at the Helmholtz Zentrum Berlin between July 2000 and December 2010. Kaplan-Meier analysis was used to obtain survival rates.

RESULTS

The Kaplan-Meier estimator for local tumor control was 92.1% at 10 years after secondary treatment with proton beam therapy. Local recurrence developed in 3 patients; 1 of them underwent enucleation. During follow-up, 20.8% of the patients died (16.7% of metastasis, 4.1% of other causes or not specified). The most frequent surgical interventions were phacoemulsification (20.8%) and pars plana vitrectomy (10.4%). The Kaplan-Meier estimators were 77.4% for survival and 70.1% for the absence of metastasis 10 years after the primary treatment.

CONCLUSIONS

Proton beam therapy as a salvage treatment resulted in high local tumor control rates in recurrent uveal melanoma, especially if the primary therapy was transpupillary thermotherapy or plaque brachytherapy. Preservation of the globe was possible in most patients. Enucleations were indicated only in case of re-recurrences of uveal melanoma, but not because of secondary complications like intractable pain or secondary glaucoma. Retreatment was associated with vision deterioration, but loss of vision remained exceptional. Further larger prospective studies are needed to confirm the presented results of our retrospective analysis.

Ionizing radiation modulates the surface expression of human leukocyte antigen-G in a human melanoma cell line

Human leukocyte antigen G (HLA-G) is a nonclassical HLA class I molecule involved in fetus protection from the maternal immune system, transplant tolerance, and viral and tumoral immune escape. Tumor-specific HLA-G expression has been described for a wide variety of malignancies, including melanomas. The aim of this study was to evaluate whether ionizing radiation (IR) could modulate the surface expression of HLA-G1 in a human melanoma cell line that expresses endogenously membrane-bound HLA-G1. For this purpose, cells were exposed to increasing doses of gamma-irradiation (0-20 Gy) and HLA-G1 levels at the plasma membrane were analyzed at different times postirradiation by flow cytometry. HLA-G total expression and the presence of the soluble form of HLA-G1 (sHLA-G1) in the culture medium of irradiated cells were also evaluated. IR was capable of downregulating cell surface and total HLA-G levels, with a concomitant increase of sHLA-G1 in the medium. These results could indicate that gamma-irradiation decreases HLA-G1 surface levels by enhancing the proteolytic cleavage of this molecule.

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.

Initial results of fractionated CyberKnife radiosurgery for uveal melanoma

OBJECTIVE

To evaluate prospectively local tumor control and morbidity after fractionated CyberKnife radiosurgery for uveal melanoma unsuitable for ruthenium-106 brachytherapy or local resection.

METHODS

This study includes melanoma > or =7 mm in initial height, or juxtapapillary and/or juxtamacular tumors (height > or =3 mm; posterior tumor margin extending to within 3 mm of optic disk rim and/or fovea). Patients were excluded if they presented evidence of echographic extrascleral tumor extension, neovascular glaucoma, or any form of pretreatment or metastases at baseline. The eye was stabilized by the same ophthalmologist via peribulbar injection of 5 cc 2% lidocaine. CyberKnife radiosurgery was performed delivering a total dose of 60 Gy to the 80% or 85% isodose line in three fractions. The planning target volume (PTV) included the contrast-enhancing lesion on MRI plus a 1-mm margin (no margin on fovea site).

RESULTS

Five patients with uveal melanoma were treated by this procedure. All patients had serous retinal detachment associated with the tumor. No grade > or =2 acute toxicities were observed. Eight-month follow-up revealed a decrease in tumor thickness in three patients and reattachment of the retina in four. The tumors remained stable in two eyes and an increase in retinal detachment was noted in one eye. Vision improved minimally in two eyes and remained stable in three.

CONCLUSION

CyberKnife fractionated radiosurgery seems to be a viable alternative local treatment modality in uveal melanoma with no serious acute side effects. Further follow-up is indicated.