Radiation induced angiosarcomas of the nasopharynx

Angiosarcoma is a malignant tumour of the vascular endothelial cell that rarely occurs in the head and neck. We present two cases arising in the nasopharynx after radiotherapy. The role of radiotherapy in carcinogenesis is considered with reference to the delay between treatment of a primary head and neck tumour and presentation with the second primary.     

Radiation induced heart disease in hypertensive rats

Spontaneously hypertensive Wistar rats were given single doses of X rays to their heart. Irradiation decreased the blood pressure before any myocardial radiation damage was apparent. Male rats, which were more hypertensive than female rats, had a shorter survival time after local heart irradiation than female rats. Antihypertensive treatment with hydralazine did not increase the survival time. It is considered that myocardial hypertrophy is the cause of the increased susceptability of spontaneously hypertensive rats to local heart irradiation.     

鼻咽癌放射治疗后第Ⅹ颅神经损伤临床分析

目的探讨鼻咽癌放射治疗后第Ⅹ颅神经损伤的临床特点、诊断、治疗、预后及影响其发生的相关因素。方法对该院1990年4月至2004年7月诊治的38例鼻咽癌放射治疗后第Ⅹ颅神经损伤患者的临床资料进行回顾性分析。结果22例在早期用激素、抗生素、大量维生素等药物治疗,7例症状轻微改善,10例无明显变化,5例病情进展。随访34例,死亡14例,现生存20例,出现神经损伤后生存1￣14年。结论放射性第Ⅹ颅神经损伤缺乏特异性的治疗手段,其发生与照射剂量、照射体积、照射技术及分次剂量等因素有关。     

鼻咽癌放射治疗后第Ⅹ颅神经损伤临床分析

 目的 探讨鼻咽癌放射治疗后第Ⅹ颅神经损伤的临床特点、诊断、治疗、预后及影响其发生的相关因素。方法 对该院1990年4月至2004年7月诊治的38例鼻咽癌放射治疗后第Ⅹ颅神经损伤患者的临床资料进行回顾性分析。结果 22例在早期用激素、抗生素、大量维生素等药物治疗，7例症状轻微改善，10例无明显变化，5例病情进展。随访34例，死亡14例，现生存20例，出现神经损伤后生存1~14年。结论 放射性第Ⅹ颅神经损伤缺乏特异性的治疗手段，其发生与照射剂量、照射体积、照射技术及分次剂量等因素有关。     

Radiation induced CNS toxicity--molecular and cellular mechanisms.

Radiotherapy of tumours proximal to normal CNS structures is limited by the sensitivity of the normal tissue. Prior to the development of prophylactic strategies or treatment protocols a detailed understanding of the mechanisms of radiation induced CNS toxicity is mandatory. Histological analysis of irradiated CNS specimens defines possible target structures prior to a delineation of cellular and molecular mechanisms. Several lesions can be distinguished: Demyelination, proliferative and degenerative glial reactions, endothelial cell loss and capillary occlusion. All changes are likely to result from complex alterations within several functional CNS compartments. Thus, a single mechanism responsible cannot be separated. At least four factors contribute to the development of CNS toxicity: (1) damage to vessel structures; (2) deletion of oligodendrocyte-2 astrocyte progenitors (O-2A) and mature oligodendrocytes; (3) deletion of neural stem cell populations in the hippocampus, cerebellum and cortex; (4) generalized alterations of cytokine expression. Several underlying cellular and molecular mechanisms involved in radiation induced CNS toxicity have been identified. The article reviews the currently available data on the cellular and molecular basis of radiation induced CNS side effects.     

Radiation induced mucositis: co-ordinating a research agenda

Aims: A one-day workshop was hosted by the Symptom Control Committee of the National Cancer Institute of Canada, Clinical Trials Group (NCIC-CTG), in conjunction with the October 2002 annual meeting of the Canadian Association of Radiation Oncologists in Toronto, Ontario. The primary intention of the workshop was to direct the future research agenda of the Symptom Control Committee. Large group presentations were held initially to review the contemporary research issues of four selected areas of interest: fatigue, brain metastasis, bone metastasis and radiation-induced mucositis. Panel members were then charged with the identification of specific research proposals that could be considered for further development. Research questions were to be clinically relevant and currently appropriate. Any additional information needed before the launch of any potential trial was also requested. In this paper, we will review and summarise the outcomes from the radiation-induced mucositis sessions.Materials and Methods: Thirty-four participants participated in the large group sessions and contributed to one of four panel discussions on selected supportive care issues relevant to radiation oncologists.Results: Three potential and non-overlapping research questions were identified; two involving mucositis management in patients receiving radical radiation for head and neck cancer, and a third for patients with advanced lung cancer undergoing combined radiation and chemotherapy and at risk for the development of symptomatic oesophagitis.Conclusion: The workshop successfully identified three potential research questions. The large group and the smaller panel discussions successfully established consensus on important aspects of future study designs. The current ‘standard of care’, appropriate experimental treatments, primary outcomes of interest and study population parameters were each important issues that were discussed. The importance of developing meaningful biological assays was reviewed, as was the need to ensure the appropriate storage of biological samples from patients for future study.     

Radiation induced sarcoma following treatment of breast cancer

The occurrence of radiation induced sarcoma following treatment of breast cancer is rare. It has an average latency of ten years and it correlates with the dose and technique of radiation. The prognosis is poor due to delay in diagnosis. We present a case where a female patient developed a chondrosarcoma of sternoclavicular joint 19 years after radiotherapy for breast cancer.     

Radiation induced adult medulloblastoma: a case report

Adult medulloblastoma is a rare intracranial tumor. Our patient is a 61 year old woman treated with cranial irradiation 15 years previously for a low grade astrocytoma in the left posterior temporal lobe that was recently diagnosed with medulloblastoma in the right cerebellum. This is the first reported case of radiation induced adult medulloblastoma.     

Radiation induced sarcomas of bone following therapeutic radiation

Because of new therapeutic trends of multi-modality and the importance of late effects, we have updated our series of radiation induced bone sarcomas seen at Memorial Sloan-Kettering Cancer Center over the past four decades. A total of 37 cases of bone sarcoma arising from normal bone in the irradiated field was analyzed. The median for latent period from irradiation to diagnosis of bone sarcoma was 11 years with a minimum latent period of four years. The median radiation dose for the bone sarcoma was 6000 rad in 6 weeks with a minimum total radiation dose of 3000 rad in 3 weeks. We have found nine patients who developed bone sarcomas in the radiation field after successful treatment of Hodgkin's disease. Criteria for radiation induced bone sarcomas and the magnitude of the risk of bone sarcomas are briefly discussed.     

宫颈癌放疗后放射性肠炎22例分析

目的探讨宫颈癌放疗后放射性肠炎的发生与后位子宫的关系及其原因。方法回顾性分析2002—2005年接受放疗的212例宫颈癌患者中发生放射性肠炎的22例患者。比较前后位子宫患者放射性肠炎的发生率,测量近阶段各15例前后位子宫患者子宫中轴(仅测C点截面)与直肠的距离,及后位子宫患者的子宫后倾后屈角度。结果后位子宫患者放射性肠炎的发生率明显高于前位子宫患者(X~2=21.10,P<0.01),后位子宫患者C点与直肠的距离较近(t=7.33,P<0.05),后位子宫患者的子宫后倾后屈角度9～22°,中位角度17°。结论后位子宫患者易于发生放射性肠炎,原因是后位子宫患者子宫中轴距直肠较近,且后装治疗中y轴与z轴在直肠方向易形成锐角关系,导致受量过大。     

Radiation induced osteochondroma in long-term survivors of childhood cancer

The records of 200 long term survivors of childhood cancer where reviewed. Radiation induced osteochondromata were detected in 12 patients (6%). Radiation had been administered in doses ranging from 1250 R (approximately 1500 rad) to 5500 rad between the ages of 8 months and 11 1/2 years. Radiation-induced osteochrondromata were detected 3 to 13 1/2 years later, with a median of 5 years. The osteochrondomata were single in 7 patients and multiple (2-4) in 5. Two occurred at sites of previous thoracotomy. Factors related to radiation induced osteochondromata are discussed.     

三维适形放射治疗胸部肿瘤致食管损伤的相关因素分析

目的:分析三维适形放射治疗胸部肿瘤时食管损伤的发生率及相关因素。方法:回顾性分析83例行三维适形放疗的胸部肿瘤患者资料,评价食管损伤并对其相关因素进行单因素和多因素分析。结果:83例患者发生急性食管炎42例(50.6%),其中1级12例(14.5%),2级25例(30.1%),3级4例(4.8%),4、5级0例;晚期食管损伤1例(1.2%)。经单因素和多因素分析显示,急性放射性食管炎与食管V50、Dmeas、是否同期放化疗有关。结论:食管放射损伤的主要原因是V50、Dmeas和同期化疗,制定放疗计划时应尽量避免食管区的高剂量照射,同时辅以放疗防护剂起一定的保护作用。     

Radiation induced renal damage in mice: Influence of fraction size

Two functional assays (urine output and isotope clearance) have been used to assess the response of mouse kidneys to localized irradiation. The influence of the size of each X ray dose has been investigated by using single doses and two to 16 equal fractions. The X ray dose in each treatment ranged from 16 Gy as a single dose to 3.5 Gy (×16 fractions). Three separate experiments were performed, one with and two without anesthetic for the irradiation. Sequential testing of the mice was used to determine the latent period before radiation damage became manifest. Latency was found to be dose dependent; functional defects appeared earlier after higher doses but there was a minimum period of 14–19 weeks before the onset of damage. The repair capacity of the kidney was assessed by comparing isoeffective doses from the dose-response curves. Within 24 hours a recovered dose of 5 Gy was obtained if 2 doses were used instead of one. The isoeffective dose increased with fractionation and a fraction number exponent of 0.42 was obtained. Analysis of the data using a linear quadratic model yielded a low $\text{α}\text{β}$ ratio of 0–3.5 Gy. This is similar to values obtained for other late responding normal tissues and implies that the use of small dose fractions will spare the kidney relative to tumors and acutely reacting normal tissues. In conventional radiotherapy more effective sparing of the kidney should be achieved by using thin shielding with each fraction than by completely shielding the kidney for the latter part of the treatment course.     

Radiation recall dermatitis induced by methotrexate in a patient with Hodgkin's disease

Radiation recall dermatitis refers to an inflammatory skin reaction at a previously irradiated field subsequent to chemotherapy administration. A number of antineoplastic agents have been reported to cause this phenomenon. We observed radiation recall dermatitis in a patient with stage IV nodular sclerosing Hodgkin's disease after methotrexate therapy for acute graft-versus-host disease (GVHD) prophylaxis. The patient had previously undergone matched related bone marrow transplantation with busulfan and cyclophosphamide as a preparative regimen. Subsequently, she received cyclosporine and methotrexate for acute GVHD prophylaxis. Two areas of skin previously irradiated to 3,000 cGy developed radiation recall dermatitis after two doses of methotrexate given 2 days apart and exacerbated by the third and fourth doses. This reaction occurred 34 days after the last dose of radiation therapy (RT). We believe this is the first case of radiation recall dermatitis after methotrexate therapy. Given the increased use of methotrexate in several neoadjuvant and adjuvant protocols in association with RT, its potential to produce radiation recall reactions should be considered.