1/12. Malignant melanoma occurring within a previously irradiated area.The commonest radiation-induced neoplasms are sarcomas. Ionizing radiation is not usually associated with the development of malignant melanoma. We report two patients with malignant melanoma occurring within a previously irradiated area. There is evidence to support radiation in the pathogenesis of melanoma but the family histories, especially in one patient, suggest that genetic mutations may also have played a role, particularly in relation to the short latent period.- - - - - - - - - - ranking = 1keywords = radiation-induced (Clic here for more details about this article) |
2/12. Gamma knife radiosurgery for metastatic tumours in the brain stem.BACKGROUND: Stereotactic radiosurgery has become important in the treatment of metastatic brain tumours and is often the first choice modality for eloquent or deep locations such as the brain stem. This study evaluated the efficacy of gamma knife radiosurgery (GKS) for the treatment of brain stem metastases. methods: The medical records of 25 patients with 31 tumours, 11 men and 14 women aged 42 to 78 years (mean 57.1 years), who underwent GKS for metastatic tumours in the brain stem were retrospectively reviewed. The results of GKS were evaluated according to the change in tumour size on neuro-imaging. FINDINGS: The most common location of the primary malignancy was the lung followed by the breast. adenocarcinoma was found in 19 patients (24 lesions). No case of squamous cell carcinoma was found. The mean calculated tumour volume was 2.1 cm(3) and the mean prescription dose to the tumour margin was 13.0 Gy. Mean duration of neuro-imaging follow up was 5.2 months and the overall tumour control rate was 77.4%. There was a significant correlation between the marginal dose delivered and the effect on neuro-imaging. New radiation-induced injury in the surrounding brain occurred in only 2 patients. INTERPRETATION: GKS for brain stem metastases using a marginal dose of 15 Gy or less is effective and relatively safe. Accurate targeting of the tumour and safe dose planning are essential to obtain satisfactory results with GKS for brain stem metastases.- - - - - - - - - - ranking = 1keywords = radiation-induced (Clic here for more details about this article) |
3/12. radiation-induced tumor after stereotactic radiosurgery and whole brain radiotherapy: case report and literature review.radiation-induced neoplasms are extremely rare after stereotactic radiosurgery. To date, only 3 cases meet Cahan's criteria in the world literature. We present a fourth case of a radiation-induced neoplasm arising after radiosurgery. The patient is a 43-year-old woman who presented with a right cerebellar anaplastic astrocytoma 64 months after radiosurgery for metastatic melanoma. Initially, 3 brain metastases involving the inferior right temporal (2 tumors) and right frontal regions were treated. Following radiosurgery, the patient underwent whole brain radiotherapy (37.5 Gy). Twenty-two months later, a second radiosurgical procedure was performed for a recurrent right temporal lobe metastasis. The area of cerebellum where the glioma developed received a maximum dose of 7.7 and 1.5 Gy during the 2 procedures, respectively. Support that radiosurgery contributed to the development of this glioma are the tumor's location and the rarity of adult cerebellar astrocytomas. The risk of radiation-induced tumors after radiosurgery is unknown. To better define the incidence of radiation-induced neoplasms after radiosurgery, all potential cases should be presented and discussed in an open, candid fashion.- - - - - - - - - - ranking = 3keywords = radiation-induced (Clic here for more details about this article) |
4/12. Cyclooxygenase-2 inhibition to treat radiation-induced brain necrosis and edema.Brain necrosis and edema develop in a proportion of brain tumor patients treated with radiosurgery. Surgical resection and corticosteroids have considerable morbidity. Two metastatic melanoma brain lesions in a 14-year-old girl were treated with radiosurgery and whole-brain radiation treatment. Both lesions became symptomatic from radiologic features of necrosis and edema and were unresponsive to oral corticosteroids. The larger lesion was resected, but the other lesion continued to enlarge. Cyclooxygenase-2 (COX-2) inhibitor was started, and the child improved clinically and radiologically. The usefulness of COX-2 inhibitors in treating radiation necrosis and edema, as suggested by this report, requires further study.- - - - - - - - - - ranking = 4keywords = radiation-induced (Clic here for more details about this article) |
5/12. Optic neuropathy secondary to radiotherapy for nasal melanoma.Optic neuropathy is a rare but important complication of radiotherapy used in the treatment of cancers of the head and neck, usually resulting in rapidly progressive blindness in one or both eyes. The case is presented of a 77-year-old woman with bilateral optic neuropathy resulting in blindness, secondary to radiotherapy for a melanoma of the nasal cavity. The onset of optic neuropathy occurred 9 months post-radiotherapy, at a cumulative dose of 6000 rad. The left eye was first involved, with the right eye becoming involved within 2 weeks. Despite treatment with oral anticoagulation and high dose intravenous methylprednisolone, there was progressive deterioration resulting in bilateral optic atrophy, with final visual acuities of perception of light in the right eye and no perception of light in the left eye. This case demonstrates that oral anticoagulation was ineffective in the treatment of progressive radiation-induced optic neuropathy.- - - - - - - - - - ranking = 1keywords = radiation-induced (Clic here for more details about this article) |
6/12. radiosurgery for the treatment of spinal melanoma metastases.BACKGROUND: The role of stereotactic radiosurgery in treating metastatic melanoma involving the spine has previously been limited. Conventional external beam radiotherapy lacks the precision to allow delivery of large single-fraction doses of radiation and simultaneously to limit the dose delivered to radiosensitive structures such as the spinal cord. This study evaluated the clinical efficacy of radiosurgery for the treatment of melanoma spinal metastases in 28 patients. methods: Thirty-six melanoma spine metastases were treated with a single-session radiosurgery technique (1 cervical, 11 thoracic, 13 lumbar, and 11 sacral) with a follow-up period of 3-43 months (median 13 months). Tumor volume ranged from 4.1 to 153 cm3 (mean 47.6 cm3). Twenty-three of the 36 lesions had received prior external beam irradiation. RESULTS: Maximum tumor dose was maintained at 17.5-25 Gy (mean 21.7 Gy). spinal cord volume receiving > 8 Gy ranged from 0.0 to 0.7 cm3 (mean 0.26 cm3); spinal canal volume at the cauda equina level receiving > 8 Gy ranged from 0.0 to 3.5 cm3 (mean 0.98 cm3). No radiation-induced toxicity occurred during the follow-up period. Axial and radicular pain improved in 27 of 28 patients (96%) who were treated primarily for pain. Long-term tumor control was seen in 3 of 4 cases treated primarily for radiographic tumor progression. Two patients went on to require open surgical intervention for tumor progression resulting in neurological deficit. CONCLUSIONS: Spinal radiosurgery offers a therapeutic modality for the safe delivery of large dose fractions of radiation therapy in a single fraction for the management of spinal metastases in patients with advanced melanoma that are often poorly controlled with alternative conventional external beam radiation therapy, and is successful even in patients with previously irradiated lesions.- - - - - - - - - - ranking = 1keywords = radiation-induced (Clic here for more details about this article) |
7/12. osteosarcoma after external beam radiation therapy for recurrent choroidal melanoma.A 59-year-old woman underwent enucleation for choroidal melanoma. She had a late recurrence of the melanoma, which was treated with surgery and radiotherapy. Nine years after radiation treatment, she presented with pain and an orbital mass. biopsy of the mass revealed an osteoblastic osteosarcoma. This report describes the late recurrence of choroidal melanoma and subsequent radiation-induced osteosarcoma. The risk of radiation-induced malignancy should be considered in all patients receiving radiotherapy. Despite yearly review, osteosarcoma was diagnosed only when the patient had symptoms, thus raising questions about the merits of long-term follow-up in detecting recurrence or emergence of secondary tumors.- - - - - - - - - - ranking = 2keywords = radiation-induced (Clic here for more details about this article) |
8/12. Pathologic examination of ciliary body melanoma treated with proton beam irradiation.Proton beam irradiation is one of the radiotherapeutic techniques currently used to manage uveal melanomas. Although this therapeutic modality has been in use for a decade and although nearly 500 patients have been so treated, there are only two published reports of the pathologic examination of these eyes. Key features found on pathologic examination of our patient's enucleated eye included vascular alterations in the tumor's blood supply, lymphocytic infiltrates, and lipoidal degeneration of tumor cells. The interval from therapy to enucleation in our patient was much longer than in the several previously reported cases, a factor allowing for the development of a more cumulative radiation effect on the tumor. The extent and degree of radiation-induced necrosis in our patient's tumor were more profound than in previous reports.- - - - - - - - - - ranking = 1keywords = radiation-induced (Clic here for more details about this article) |
9/12. Proton-beam irradiated epithelioid cell melanoma of the ciliary body.A malignant ciliary body melanoma received proton-beam irradiation. After an apparent failure of the tumor to respond, the eye was enucleated. A predominantly epithelioid cell tumor appeared viable by light microscopy, and a low degree of mitotic activity persisted, despite therapy. The tumor cells, however, displayed degenerative changes ultrastructurally, presumably results of the radiotherapy. These consisted of numerous cytoskeletal filaments, lipid vacuoles, prominent phagolysosomes, and nuclear convolutions and fragmentations. The mitochondria were fewer in number in the present tumor than typically encountered in epithelioid cells. A rare leptomeric structure was discovered, probably an organizational modification of the cytoplasmic filaments. The tumor's capillaries showed radiation-induced changes in terms of thickened basement membranes and perivascular fibrin deposition. The foregoing features are indicative of cellular and metabolic injury from the radiotherapy, but these were evidently not sufficiently injurious to sterilize the tumor.- - - - - - - - - - ranking = 1keywords = radiation-induced (Clic here for more details about this article) |
10/12. dysplastic nevus syndrome with multiple primary amelanotic melanomas in oculocutaneous albinism.Melanomas are rare in albinos, although the incidence of solar radiation-induced skin tumors is extremely high because of the absence of photoprotective melanin. This report describes a 40-year-old white woman with tyrosinase-negative oculocutaneous albinism who developed four primary amelanotic melanomas--three of the superficial spreading and one of the nodular type-and, in addition, displayed nevi that exhibited histologically the characteristic features of dysplastic nevi. The concomitant occurrence of multiple primary melanomas and several dysplastic nevi classifies the patient's condition as "dysplastic nevus syndrome," which to our knowledge has not been described in albinism so far.- - - - - - - - - - ranking = 1keywords = radiation-induced (Clic here for more details about this article) |
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