Malignant mesotheliomas are rather uncommon neoplasms associated primarily with asbestos exposure; however, they may also arise as second primary malignancies after radiation therapy, with a latency period of 15–25 y...Malignant mesotheliomas are rather uncommon neoplasms associated primarily with asbestos exposure; however, they may also arise as second primary malignancies after radiation therapy, with a latency period of 15–25 years. Numerous studies have reported an association between pleural malignant mesothelioma and chest radiation performed for other malignancies; on the other hand, post-irradiation mesotheliomas of the pericardium have been reported in only a few published cases to date, and no homozygous deletion of 9 p21 has been described in such cases. We report the case of a 48-year-old man with a history of Hodgkin's lymphoma and no prior asbestos exposure who developed pericardial malignant epithelioid mesothelioma. We further discuss the cytologic, histologic, immunophenotypic, and fluorescence in situ hybridization findings in this case. To our knowledge, this is the first well-documented case of post-radiation pericardial malignant mesothelioma showing homozygous deletion of 9 p21. Homozygous deletion of 9 p21, the locus harboring the p16 gene, is present in post-irradiation pericardial malignant mesothelioma.展开更多
With improved outcomes associated with radiotherapy, radiation-induced sarcomas(RIS) are increasingly seen in long-term survivors of head and neck cancers, with an estimated risk of up to 0.3%. They exhibit no subsite...With improved outcomes associated with radiotherapy, radiation-induced sarcomas(RIS) are increasingly seen in long-term survivors of head and neck cancers, with an estimated risk of up to 0.3%. They exhibit no subsite predilection within the head and neck and can arise in any irradiated tissue of mesenchymal origin. Common histologic subtypes of RIS parallel their de novo counterparts and include osteosarcoma, chondrosarcoma, malignant fibrous histiocytoma/sarcoma nitricoxide synthase, and fibrosarcoma. While imaging features of RIS are not pathognomonic, large size, extensive local invasion with bony destruction, marked enhancement within a prior radiotherapy field, and an appropriate latency period are suggestive of a diagnosis of RIS. RIS development may be influenced by factors such as radiation dose, age at initial exposure, exposure to chemotherapeutic agents and genetic tendency. Precise pathogenetic mechanisms of RIS are poorly understood and both directly mutagenizing effects of radiotherapy as well as changes in microenvironments are thought to play a role. Management of RIS is challenging, entailing surgery in irradiated tissue and a limited scope for further radiotherapy and chemotherapy. RIS is associated with significantly poorer outcomes than stagematched sarcomas that arise independent of irradiationand surgical resection with clear margins seems to offer the best chance for cure.展开更多
Reference Standard Dosimeters are used to calibrate radiation environments and routine dosimeters. It can also be used in routine dosimetry applications for radiation processing where higher quality dosimetry measurem...Reference Standard Dosimeters are used to calibrate radiation environments and routine dosimeters. It can also be used in routine dosimetry applications for radiation processing where higher quality dosimetry measurements are required. Electron Spin Resonance (ESR) is a well-established Reference Standard Dosimetry system in industrial applications of ionising radiation, and its use is also proposed in radiation therapy and accident dosimetry. In the present experimental work, PGA solid state dosimeter (SSD) has been investigated using ESR spectroscopy to study the gamma radiation response of this material and to evaluate its dosimetric characteristics: dose response, room temperature fading, heat treatment effect during post-irradiation storage. Results obtained up to now confirm that PGA seems to be suitable material for ESR dosimetry applications.展开更多
文摘Malignant mesotheliomas are rather uncommon neoplasms associated primarily with asbestos exposure; however, they may also arise as second primary malignancies after radiation therapy, with a latency period of 15–25 years. Numerous studies have reported an association between pleural malignant mesothelioma and chest radiation performed for other malignancies; on the other hand, post-irradiation mesotheliomas of the pericardium have been reported in only a few published cases to date, and no homozygous deletion of 9 p21 has been described in such cases. We report the case of a 48-year-old man with a history of Hodgkin's lymphoma and no prior asbestos exposure who developed pericardial malignant epithelioid mesothelioma. We further discuss the cytologic, histologic, immunophenotypic, and fluorescence in situ hybridization findings in this case. To our knowledge, this is the first well-documented case of post-radiation pericardial malignant mesothelioma showing homozygous deletion of 9 p21. Homozygous deletion of 9 p21, the locus harboring the p16 gene, is present in post-irradiation pericardial malignant mesothelioma.
文摘With improved outcomes associated with radiotherapy, radiation-induced sarcomas(RIS) are increasingly seen in long-term survivors of head and neck cancers, with an estimated risk of up to 0.3%. They exhibit no subsite predilection within the head and neck and can arise in any irradiated tissue of mesenchymal origin. Common histologic subtypes of RIS parallel their de novo counterparts and include osteosarcoma, chondrosarcoma, malignant fibrous histiocytoma/sarcoma nitricoxide synthase, and fibrosarcoma. While imaging features of RIS are not pathognomonic, large size, extensive local invasion with bony destruction, marked enhancement within a prior radiotherapy field, and an appropriate latency period are suggestive of a diagnosis of RIS. RIS development may be influenced by factors such as radiation dose, age at initial exposure, exposure to chemotherapeutic agents and genetic tendency. Precise pathogenetic mechanisms of RIS are poorly understood and both directly mutagenizing effects of radiotherapy as well as changes in microenvironments are thought to play a role. Management of RIS is challenging, entailing surgery in irradiated tissue and a limited scope for further radiotherapy and chemotherapy. RIS is associated with significantly poorer outcomes than stagematched sarcomas that arise independent of irradiationand surgical resection with clear margins seems to offer the best chance for cure.
文摘Reference Standard Dosimeters are used to calibrate radiation environments and routine dosimeters. It can also be used in routine dosimetry applications for radiation processing where higher quality dosimetry measurements are required. Electron Spin Resonance (ESR) is a well-established Reference Standard Dosimetry system in industrial applications of ionising radiation, and its use is also proposed in radiation therapy and accident dosimetry. In the present experimental work, PGA solid state dosimeter (SSD) has been investigated using ESR spectroscopy to study the gamma radiation response of this material and to evaluate its dosimetric characteristics: dose response, room temperature fading, heat treatment effect during post-irradiation storage. Results obtained up to now confirm that PGA seems to be suitable material for ESR dosimetry applications.
