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1/46. Partially resected and irradiated cerebellar astrocytoma of childhood: malignant evolution after 28 years.

    Partial resection of a cystic cerebellar astrocytoma with well-differentiated histomorphology in a 13 year old girl was followed by a course of x-ray therapy. After a period of 27 years symptoms recurred. The patient died 2 days after a second operation, and autopsy showed a large partly cystic cerebellar astrocytoma with distinct morphological evidence of malignancy in some areas. The role of the x-ray therapy in the formation of peculiar bizarre giant cells in our case is discussed. Radio-induction of malignant tumour evolution after long latency has to be considered, but the possibility seems remote. However, the value of radiotherapy for cystic cerebellar astrocytomas needs some reconsideration. More caution in the long term prognosis of cystic cerebellar astrocytomas of childhood might be appropriate.
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2/46. Atypical tentorial meningioma 30 years after radiotherapy for a pituitary adenoma.

    Although the human central nervous system used to be considered relatively resistant to the carcinogenic action of ionizing radiation, several lines of evidence now document a high incidence of secondary tumors in irradiated patients. The numerous reports of radiation-induced cerebral meningiomas generally distinguish those induced by high-dose radiation from those induced by low-dose radiation. We describe the case of patient who underwent subtotal resection of a chromophobe pituitary adenoma at the age of 18 years, who was successively treated by conventional fractionated radiotherapy with gamma rays emitted by a source of 60Co until a total dose of 41 Gy. Over the next 30 years the patient experienced all the known late effects of radiation, including panhypopituitarism, cranial-nerve deficits (II, III and VI), massive radiation necrosis involving the left cerebral hemisphere and causing right hemiparesis and aphasia and, ultimately, an atypical tentorial meningioma with early recurrence after total resection.
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3/46. Potential reduction of the incidence of radiation-induced second cancers by using proton beams in the treatment of pediatric tumors.

    PURPOSE: To assess the potential influence of improved dose distribution with proton beams compared to conventional or intensity-modulated (IM) X-ray beams on the incidence of treatment-induced secondary cancers in pediatric oncology. methods AND MATERIALS: Two children, one with a parameningeal rhabdomyosarcoma (RMS) and a second with a medulloblastoma, were used as models for the purpose of this study. After defining the target and critical structures, treatment plans were calculated and optimized, four for the RMS case (conventional X-ray, IM x-rays, protons, and IM protons) and three for the irradiation of the spinal axis in medulloblastoma (conventional X-ray, IM x-rays, protons). Secondary cancer incidence was estimated using a model based on Publication No. 60 of the International Commission on Radiologic Protection. This model allowed estimation of absolute risks of secondary cancer for each treatment plan based on dose-volume distributions for the nontarget organs. RESULTS: Proton beams reduced the expected incidence of radiation-induced secondary cancers for the RMS patient by a factor of >or=2 and for the medulloblastoma case by a factor of 8 to 15 when compared with either IM or conventional X-ray plans. CONCLUSIONS: The potential for a significant reduction in secondary cancers with pediatric cancers after using proton beams (forward planned or IM) in the treatment of RMS and MBD in children and adolescents represents an additional argument supporting the development of proton therapy for most radiotherapy indications in pediatric oncology.
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4/46. Uterine papillary serous carcinoma after pelvic radiation therapy for cancer of the cervix.

    The carcinogenic effect of ionising radiation in humans has well documented in both atomic bomb survivors and patients exposed to therapeutic radiation. patients irradiated for cancer of cervix have frequently been studied for the later development of secondary malignancies because treatment is relatively successful and many patients survive long enough to be at risk for late complications of radiotherapy. Most investigations have revealed an increased incidence of uterine sarcoma following pelvic radiation therapy for a variety of gynecologic disorders (Norris and Taylor, 1965; Fehr and Prem, 1974). Wagoner, in a review of over 1800 women treated with ionising radiation for invasive cervical cancer, reported a fourfold increase in risk for the later development of uterine sarcoma (Wagoner, 1984). In this paper we report the case of uterine papillary serous carcinoma 16 years after pelvic x-ray therapy for cervical cancer.
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5/46. Malignant melanoma arising in a radiotherapy field: report of two cases and review of the literature.

    We report 2 patients who developed melanoma or melanoma metastases in radiation fields 6 and 43 years after radiation therapy, respectively. One of the patients had received adjuvant hyperfractionated photon therapy for Ewing sarcoma, while the other patient had received x-ray therapy for a hemangioma. While postradiation secondary cancers with a long latency period are not uncommon, the development of melanoma is exceedingly rare.
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6/46. radiation-induced osteosarcoma of the calvaria--case report.

    The authors report a case of radiation-induced calvarial osteosarcoma. A 58-year-old female received subtotal removal of the pituitary adenoma and 5000 rads postoperative irradiation. Seven years later, an osteoblastic osteosarcoma occurred in the frontotemporal region. She received total tumor removal and chemotherapy. However, computed tomography subsequently revealed multiple small lesions at the margin of the bone flap. A chest x-ray film demonstrated lung metastasis. Local recurrence and lung metastasis require careful attention in radiation-induced osteosarcoma patients.
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7/46. osteosarcoma as a second malignant neoplasm in children.

    Nine patients who had an osteosarcoma that had developed as a second malignant neoplasm in a previously irradiated site were managed at a major center for the treatment of tumors in children. The doses of radiation had averaged 4144 centigray (range, 2300 to 8000 centigray) and chemotherapy had been administered, when appropriate, for the primary malignant lesion (Ewing sarcoma, malignant fibrous histiocytoma, Hodgkin lymphoma, neuroblastoma, neurofibrosarcoma, rhabdomyosarcoma, and wilms tumor). The interval between the initial treatment and the diagnosis of the secondary sarcoma averaged ten years and one month (range, five years and ten months to twenty-one years and nine months). Three patients were alive, two of them with active disease, at the time of writing. The other six had died within three years (average, fifteen months) after the second diagnosis. The prevalence of secondary osteosarcoma is increasing as the survival of children who have a malignant lesion increases. Plans for tumor therapy should take into account the risk of this complication, which is usually fatal.
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8/46. tissue distribution of Thorotrast and role of internal irradiation in carcinogenesis.

    carcinogenesis in Thorotrastosis has been assumed due to direct bombardment by alpha-particle with high linear energy transfer during decay of 232Th. To revisit the mechanism of carcinogenesis by Thorotrast (THR), we examined the tissue distribution of THR granules and two-dimensional distribution of radioactivity in the organs of Thorotrastosis patients and studied their spatial relationship to histopathological changes. The high radioactivity in the patients' organ was predominantly derived from decay of thorium series and showed unique distribution, while the far lower natural radioactivity was mainly from uranium series decay and fairly evenly distributed. It was found that a large majority of THR granules were phagocytized by macrophages and were embedded in extensive fibrosis. Cancer was rarely in the center of THR deposition but rather at a distance from the deposits. These observations may indicate that the predominant feature of THR deposition is the tissue damage by direct hit of alpha-particles and subsequent fibrosis. The effect of THR resembles action of toxic chemical agents, as several authors have pointed out. We therefore assume that carcinogenesis in Thorotrastosis is a combination of events, such as regeneration of liver tissue after radiation damage, emission of secondary electrons, ionization of the surrounding tissue, and beta- or gamma-ray from daughter nuclei of thorium (Th). In this context, the role of alpha-particle is important but more intriguing.
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9/46. Intracranial meningiomas developing at long intervals following low-dose X-ray irradiation of the head.

    Five patients are reported who underwent X-ray epilation in childhood for tinea capitis and who developed meningiomas after about four decades. X-ray irradiation resulted in permanent alopecia in four of the five patients. In four patients the tumors were found on the convexity, one patient had a tuberculum sellae meningioma. All five patients underwent surgery. recurrence was noted in three of the five patients, one of them was reoperated. No malignant features, but signs of atypia were found at histopathological examination. The development of meningiomas after low-dose irradiation with long latency periods, the predominant calvarial location of the tumors, the high recurrence rates, the absence of malignant traits but the presence of atypias are features overwhelmingly common with similar cases published in the literature. The fact that two of the five patients were sisters stresses the importance of genetic factors in the evolution of these tumors.
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10/46. Basal cell carcinoma and world war ii-era cathode ray oscilloscope exposure.

    BACKGROUND: There is a high prevalence of skin cancer in world war ii servicemen stationed in the Pacific theater as a result of various risk factors such as exposure to ultraviolet radiation and genetic predisposition. OBJECTIVE: We sought to describe whether a possible association exists between basal cell carcinoma (BCC) development and the use of high-voltage cathode ray tube (CRT) oscilloscopes manufactured around 1940 to 1955, which were a source of X-radiation. methods: We present a case series of 9 men aged 65 to 93 years who presented with similar head and neck distributions of BCC and a history of extensive use of early CRT oscilloscopes during and shortly after the world war ii era. The patients were interviewed and their medical records reviewed to determine CRT exposure times and BCC location, subtype, and treatment. Representative BCC histologic sections were reviewed. RESULTS: A total of 230 BCCs of the head and neck region were identified and mapped. questionnaires determined a minimum exposure of 600 (range, 624-9600) hours within a 60-cm distance of early CRT screens in all patients. The average number of aggressive histologic subtypes was 23.5%. The average number of Mohs micrographic surgery layers required to obtain negative margins was 1.99 compared with 1.63 in the control group treated by the same Mohs micrographic surgeon (P < .002). CONCLUSION: This descriptive study is the first to suggest that ionizing radiation from early CRT oscilloscopes may be a factor in the development of multiple BCCs of the head and neck with increased subclinical spread.
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