Uveal Melanoma Recurrence After Fractionated Proton Beam Therapy: Comparison of Survival in Patients Treated With Reirradiation or With Enucleation

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.

Survival of patients with recurrent uveal melanoma after treatment with radiation therapy

BACKGROUND/AIMS

We evaluated a large cohort of patients treated for local recurrence of choroidal or ciliary body melanomas at the Massachusetts Eye and Ear (MEE) to quantify the risk of melanoma-related mortality associated with recurrence, independent of other risk factors.

METHODS

Patients treated with radiation therapy from 1982 to 2017 were identified through the Uveal Melanoma Registry at MEE. Competing risks regression was performed to investigate the risk of melanoma-related mortality associated with recurrence, treating recurrence as a time-varying covariate.

RESULTS

Of 4196 patients treated, 4043 patients remained recurrence-free and 153 patients experienced a recurrence (median follow-up: 9.9 years). Median time from initial treatment to recurrence was 30.5 months (range: 2.0-238.7). Seventy-nine (69.9%) patients with recurrences and 826 (37.9%) patients in the recurrence-free group died of metastatic uveal melanoma (p<0.001). Median time from initial treatment to melanoma-related death was 4.9 years (1.0-31.8) for patients who developed recurrences and 4.3 years (0.59-33.8) for patients who did not (p=0.17). Five-year and 10-year probabilities of melanoma-related mortality were 9.5% and 15.0%, respectively, in patients without local recurrences compared with 32.0% and 46.6% in patients with recurrences (p<0.001).

CONCLUSION

These data confirm previous reports that local recurrence is associated with an increased risk of dying of melanoma and quantify the risk that can be attributed to local recurrence independent of other risk factors. This group of patients should be strongly considered for adjuvant therapies when available.

Role of proton therapy in reirradiation and in the treatment of sarcomas

Reirradiation and irradiation of sarcoma is often difficult due to the frequent need for a high dose of radiation in order to increase tumor control. This can result in a greater risk of toxicity which can be mitigated with the use of proton therapy. The present review aims to summarize the role of proton therapy in these 2 clinical contexts.

A Systematic Review on Re-irradiation with Charged Particle Beam Therapy in the Management of Locally Recurrent Skull Base and Head and Neck Tumors

Purpose

To evaluate the clinical outcomes and treatment related toxicities of charged particle-based re-irradiation (reRT; protons and carbon ions) for the definitive management of recurrent or second primary skull base and head and neck tumors.

Materials and Methods

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were applied for the conduct of this systematic review. Published work in English language evaluating the role of definitive charged particle therapies in the clinical setting of reRT for recurrent or second primary skull base and head and neck tumors were eligible for this analysis.

Results

A total of 26 original studies (15 protons, 10 carbon ions, and 1 helium/neon studies) involving a total of 1,118 patients (437 with protons, 670 with carbon ions, and 11 with helium/neon) treated with curative-intent charged particle reRT were included in this systematic review. All studies were retrospective in nature, and the majority of them (n=23, 88 %) were reported as single institution experiences (87% for protons, and 90% for carbon ion-based studies). The median proton therapy reRT dose was 64.5 Gy (RBE 1.1) (range, 50.0 – 75.6 Gy ), while the median carbon ion reRT dose was 53.8 Gy (RBE 2.5 – 3.0) (range, 44.8 – 60 Gy ). Induction and/or concurrent chemotherapy was administered to 232 (53%) of the patients that received a course of proton reRT, and 122 (18%) for carbon ion reRT patients. ReRT with protons achieved 2-year local control rates ranging from 50% to 86%, and 41% to 92% for carbon ion reRT. The 2-year overall survival rates for proton and carbon ion reRT ranged from 33% to 80%, and 50% to 86% respectively. Late ≥ G3 toxicities ranged from 0% to 37%, with brain necrosis, ototoxicity, visual deficits, and bleeding as the most common complications. Grade 5 toxicities for all treated patients occurred in 1.4% (n= 16/1118) with fatal bleeding as the leading cause.

Conclusions

Based on current data, curative intent skull base and head and neck reRT with charged particle radiotherapy is feasible and safe in well-selected cases, associated with comparable or potentially improved local control and toxicity rates compared to historical reRT studies using photon radiotherapy. Prospective multi-institutional studies reporting oncologic outcomes, toxicity, and dosimetric treatment planning data are warranted to further validate these findings and to improve the understanding of the clinical benefits of charged particle radiotherapy in the reRT setting.

Particle therapy tumour outcomes: An updated systematic review

Particle therapy (PT) offers the potential for reduced normal tissue damage as well as escalation of target dose, thereby enhancing the therapeutic ratio in radiation therapy. Reflecting the building momentum of PT use worldwide, construction has recently commenced for The Australian Bragg Centre for Proton Therapy and Research in Adelaide - the first PT centre in Australia. This systematic review aims to update the clinical evidence base for PT, both proton beam and carbon ion therapy. The purpose is to inform clinical decision-making for referral of patients to PT centres in Australia as they become operational and overseas in the interim. Three major databases were searched by two independent researchers, and evidence quality was classified according to the National Health and Medical Research Council evidence hierarchy. One hundred and thirty-six studies were included, two-thirds related to proton beam therapy alone. PT at the very least provides equivalent tumour outcomes compared to photon controls with the possibility of improved control in the case of carbon ion therapy. There is suggestion of reduced morbidities in a range of tumour sites, supporting the predictions from dosimetric modelling and the wide international acceptance of PT for specific indications based on this. Though promising, this needs to be counterbalanced by the overall low quality of evidence found, with 90% of studies of level IV (case series) evidence. Prospective comparative clinical trials, supplemented by database-derived outcome information, preferably conducted within international and national networks, are strongly recommended as PT is introduced into Australasia.

[Indications and results for protontherapy in cancer treatments]

Purpose was to summarize results for proton therapy in cancer treatment. A systematic review has been done by selecting studies on the website www.pubmed.com (Medline) and using the following keywords: proton therapy, radiation therapy, cancer, chordoma, chondrosarcoma, uveal melanoma, retinoblastoma, meningioma, glioma, neurinoma, pituitary adenoma, medulloblastoma, ependymoma, craniopharyngioma and nasal cavity. There are several retrospective studies reporting results for proton therapy in cancer treatments in the following indications: ocular tumors, nasal tumors, skull-based tumors, pediatric tumors. There is no prospective study except one phase II trial in medulloblastoma. The use of proton therapy for these indications is due to dosimetric advantages offering better tumor coverage and organ at risk sparing in comparison with photon therapy. Clinical results are historically at least as efficient as photon therapy with a better toxicity profile in pediatric tumors (cognitive and endocrine functions, radiation-induced cancer) and a better tumoral control in tumors of the nasal cavity. Clinical advantages of proton therapy counterbalance its cost especially in pediatric tumors. Proton therapy could be used in other types of cancer. Proton therapy showed good outcome in ocular, nasal tumors, pediatric, skull-based and paraspinal tumors. Because of some dosimetric advantages, proton therapy could be proposed for other indications in cancer treatments.

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.

Ruthenium-106 brachytherapy for thick uveal melanoma: reappraisal of apex and base dose radiation and dose rate

Purpose

To evaluate the outcomes of ruthenium-106 (¹⁰⁶Ru) brachytherapy in terms of radiation parameters in patients with thick uveal melanomas.

Material and methods

Medical records of 51 patients with thick (thickness ≥ 7 mm and < 11 mm) uveal melanoma treated with ¹⁰⁶Ru brachytherapy during a ten-year period were reviewed. Radiation parameters, tumor regression, best corrected visual acuity (BCVA), and treatment-related complications were assessed.

Results

Fifty one eyes of 51 consecutive patients including 25 men and 26 women with a mean age of 50.5 ± 15.2 years were enrolled. Patients were followed for 36.1 ± 26.5 months (mean ± SD). Mean radiation dose to tumor apex and to sclera were 71 (± 19.2) Gy and 1269 (± 168.2) Gy. Radiation dose rates to tumor apex and to sclera were 0.37 (± 0.14) Gy/h and 6.44 (± 1.50) Gy/h. Globe preservation was achieved in 82.4%. Preoperative mean tumor thickness of 8.1 (± 0.9) mm decreased to 4.5 (± 1.6) mm, 3.4 (± 1.4) mm, and 3.0 (± 1.46) mm at 12, 24, and 48 months after brachytherapy (p = 0.03). Four eyes that did not show regression after 6 months of brachytherapy were enucleated. Secondary enucleation was performed in 5 eyes because of tumor recurrence or neovascular glaucoma. Tumor recurrence was evident in 6 (11.8%) patients. Mean Log MAR (magnification requirement) visual acuity declined from 0.75 (± 0.63) to 0.94 (± 0.5) (p = 0.04). Best corrected visual acuity of 20/200 or worse was recorded in 37% of the patients at the time of diagnosis and 61.7% of the patients at last exam (p = 0.04). Non-proliferative and proliferative radiation-induced retinopathy was observed in 20 and 7 eyes.

Conclusions

Thick uveal melanomas are amenable to ¹⁰⁶Ru brachytherapy with less than recommended apex radiation dose and dose rates.

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.

Risk factors associated with secondary enucleation after fractionated stereotactic radiotherapy in uveal melanoma

PURPOSE

To evaluate risk factors for secondary enucleation after fractionated stereotactic radiotherapy (fSRT) in uveal melanoma.

METHODS

In this retrospective study, clinical data of 118 consecutive patients who had initially been treated with fSRT between 1999 and 2009 were collected and analysed. The patients who had undergone secondary enucleation were identified and examined for clinical, histopathological and cytogenetical (fluorescence in situ hybridization determined) data. Also, the reasons for secondary enucleation, such as treatment failure (progressive tumour growth or tumour recurrence) or complications following fSRT (painful blind eye), were recorded and examined.

RESULTS

The secondary enucleation rate was 16% after a median follow-up of 4.7 years, with 5% due to treatment failure and 11% due to complications. In the univariate analysis, large tumour diameter (p = 0.019) and large tumour height (p = 0.001) were associated with secondary enucleation, tumour involvement of the optic disc showed borderline significance (p = 0.068). Cox regression multivariate analysis displayed large tumour height as independent prognostic factor (HR 1.42, 95% CI 1.12-1.81, p = 0.004). Following secondary enucleation, mitotic figures were present in five of 18 tumours, and gain of chromosome 8q was also present in five tumours. Within the subgroup of patients who required secondary enucleation due to failed tumour control by fSRT (N = 6), mitotic figures were present in four of six tumours while gain of 8q was present in three of six tumours.

CONCLUSION

Secondary enucleation after previous fSRT was associated with large tumour height. High mitotic counts and gain of chromosome 8q were frequently found in secondary enucleations and possibly indicate a more aggressive or radiation-resistant tumour.

Cost-effectiveness of proton beam therapy for intraocular melanoma

Purpose

Proton beam therapy is a commonly accepted treatment for intraocular melanomas, but the literature is lacking in descriptions of patient preferences of clinical outcomes and economic impact. In addition, no economic evaluations have been published regarding the incremental cost-effectiveness of proton beam therapy compared with enucleation or plaque brachytherapy, typical alternative treatments. We, therefore, conducted a cost-utility analysis of these three approaches for the treatment of intraocular melanomas.

Materials and Methods

A Markov model was constructed. Model parameters were identified from the published literature and publicly available data sources. Cost-effectiveness of each treatment was calculated in 2011 US Dollars per quality-adjusted life-year. Incremental cost-effectiveness ratios were calculated assuming enucleation as reference. One-way sensitivity analyses were conducted on all model parameters. A decision threshold of $50,000/quality-adjusted life-year was used to determine cost-effectiveness.

Results

Enucleation had the lowest costs and quality-adjusted life-years, and plaque brachytherapy had the highest costs and quality-adjusted life-years. Compared with enucleation, the base-case incremental cost-effectiveness ratios for plaque brachytherapy and proton beam therapy were $77,500/quality-adjusted life-year and $106,100/quality-adjusted life-year, respectively. Results were highly sensitive to multiple parameters. All three treatments were considered optimal, and even dominant, depending on the values used for sensitive parameters.

Conclusion

Base-case analysis results suggest enucleation to be optimal. However, the optimal choice was not robust to sensitivity analyses and, depending on the assumption, both plaque brachytherapy and proton beam therapy could be considered cost-effective. Future clinical studies should focus on generating further evidence with the greatest parameter uncertainty to inform future cost-effectiveness analyses.

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.

Recommendations for the referral of patients for proton-beam therapy, an Alberta Health Services report: a model for Canada?

BACKGROUND

Compared with photon therapy, proton-beam therapy (pbt) offers compelling advantages in physical dose distribution. Worldwide, gantry-based proton facilities are increasing in number, but no such facilities exist in Canada. To access pbt, Canadian patients must travel abroad for treatment at high cost. In the face of limited access, this report seeks to provide recommendations for the selection of patients most likely to benefit from pbt and suggests an out-of-country referral process.

METHODS

The medline, embase, PubMed, and Cochrane databases were systematically searched for studies published between January 1990 and May 2014 that evaluated clinical outcomes after pbt. A draft report developed through a review of evidence was externally reviewed and then approved by the Alberta Health Services Cancer Care Proton Therapy Guidelines steering committee.

RESULTS

Proton therapy is often used to treat tumours close to radiosensitive tissues and to treat children at risk of developing significant late effects of radiation therapy (rt). In uncontrolled and retrospective studies, local control rates with pbt appear similar to, or in some cases higher than, photon rt. Randomized trials comparing equivalent doses of pbt and photon rt are not available.

SUMMARY

Referral for pbt is recommended for patients who are being treated with curative intent and with an expectation for long-term survival, and who are able and willing to travel abroad to a proton facility. Commonly accepted indications for referral include chordoma and chondrosarcoma, intraocular melanoma, and solid tumours in children and adolescents who have the greatest risk for long-term sequelae. Current data do not provide sufficient evidence to recommend routine referral of patients with most head-and-neck, breast, lung, gastrointestinal tract, and pelvic cancers, including prostate cancer. It is recommended that all referrals be considered by a multidisciplinary team to select appropriate cases.

Quantification of dose perturbations induced by external and internal accessories in ocular proton therapy and evaluation of their dosimetric impact

PURPOSE

Proton scattering on beam shaping devices and protons slowing down on media with different densities within the treatment volume may produce dose perturbations and range variations that are not predicted by treatment planning systems. The aim of this work was to assess the dosimetric impact of elements present in ocular proton therapy treatments that may disturb the prescribed treatment plan. Both distal beam shaping devices and intraocular elements were considered.

METHODS

A wedge filter, tantalum fiducial marker, hemispherical compensator, two intraocular endotamponades (densities 0.97 and 1.92 g cm(-3)) and an intraocular eye lens (IOL) were considered in the study. For these elements, longitudinal dose distributions were measured and∕or calculated in water in beam alignment for a clinical spread-out Bragg peak. Under the same conditions, the unperturbed dose distributions were similarly measured and∕or calculated in the absence of the element. The dosimetric impact was assessed by comparison of unperturbed and perturbed dose distributions. Measurements and calculations were carried out with two methods. Measurements are based on EBT3 films with dedicated software, which makes use of a calibration curve and correction for the quenching effect. Calculations are based on the Monte Carlo (MC) code MCNPX and reproduce the experimental conditions. Both dose maps are obtained with a resolution of 300 dpi.

RESULTS

The degree of disturbance of distal beam shaping devices is low for the wedge filter (2% overdose ripple all along the central axis) and moderate for the hemispherical compensator (two bands of variable overdose of up to 10% downstream the compensator lateral edges and -5% underdose on the plateau at off-axis distance of 5 cm). Tantalum clips produce important dose shadows (-20% behind the clip parallel to the beam and range reduction of 1.1 mm) and bands of overdose (15%). The presence of endotamponades modifies the dose distribution very significantly (-5% underdose on the plateau and 3 mm range prolongation for the tamponade with density 0.97 g cm(-3) and -15% underdose on plateau and 8 mm range reduction for that with density 1.92 g cm(-3)). No dose perturbations were found for the IOL. The high performance of EBT3 film and MC tools used was confirmed and good agreement was found between them (percentage of pixels passing the gamma test >87%).

CONCLUSIONS

The degree of disturbance by external beam shaping devices remains low in ocular proton therapy and can be reduced by bringing accessories closer to the eye. Tantalum fiducial markers must be located in such a way that dose perturbation is not projected on the tumor. The treatment of patients with intraocular endotamponades must be carefully managed. It is fundamental that radiation oncologists and medical physicists are informed about the presence of such substances prior to the treatment.

Proton beam radiotherapy of uveal melanoma

Proton beam radiotherapy of uveal melanoma can be administered as primary treatment, as salvage therapy for recurrent tumor, and as neoadjuvant therapy prior to surgical resection. The physical properties of proton beams make it possible to deliver high-doses of radiation to the tumor with relative sparing of adjacent tissues. This form of therapy is effective for a wider range of uveal melanoma than any other modality, providing exceptionally-high rates of local tumor control. This is particularly the case with diffuse iris melanomas, many of which are unresectable. The chances of survival, ocular conservation, visual preservation and avoidance of iatrogenic morbidity depend greatly on the tumor size, location and extent. When treating any side-effects and/or complications, it is helpful to consider whether these are the result of collateral damage or persistence of the irradiated tumor ('toxic tumor syndrome').

Ocular Melanoma and Other Unusual Sites

Noncutaneous melanoma is a rare entity for which there is still no agreement about management. The rarity of this disease has resulted in a lack of significant investigation and insufficient opportunity to evaluate the epidemiologic features, risk factors, and the most useful diagnostic and therapeutic approaches. Noncutaneous melanomas are characterized by poor prognosis, and the diagnosis is usually delayed because of their unusual locations and lack of physician awareness. This review focuses principally on ocular melanoma, the most frequent noncutaneous melanoma, for which each aspect of the disease is described. The potential utility of nuclear medicine procedures is also considered.