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Published in Henry J. Woodford, Essential Geriatrics, 2022
External beam radiotherapy uses high-energy X-ray beams to damage the DNA in cancer cells, which have reduced DNA repair mechanisms. The aim is to limit damage to surrounding, non-cancerous tissues. The total dose is divided into daily fractions. The duration can vary from one day to eight weeks, tending to be longer when the intent is cure rather than palliation. It can be used with other treatment strategies, concurrently or in sequence. Radiotherapy is a component of around 40% of curative cancer treatments and a small proportion of cancers can be cured by radiotherapy alone.34 For older people, it is particularly useful for non-melanoma skin cancers. Examples of palliative radiotherapy are pain relief (e.g. bone metastases), tumour shrinkage (e.g. cerebral metastases or spinal cord compression) or haemorrhage control. Potential adverse effects include fatigue and local tissue irritation (e.g. pain), which usually improve over a few weeks. Long-term adverse effects can include fibrosis, alternations to blood supply and a small risk of secondary malignancies. Brain radiotherapy could increase the risk of cognitive impairment.
Clinical Application of IVIM in the Female Pelvis
Published in Denis Le Bihan, Mami Iima, Christian Federau, Eric E. Sigmund, Intravoxel Incoherent Motion (IVIM) MRI, 2018
Elaine Y. P. Lee, Pek-Lan Khong
The standard treatment regimen for locally advanced cervical cancer is concurrent chemoradiotherapy (CCRT). This usually takes the form of four to five weeks of external beam radiotherapy to the whole pelvis and weekly cisplatin-based chemotherapy. Given the role of MRI in the pretreatment evaluation of cervical cancer, it is increasingly used in treatment response assessment during and following CCRT. However, assessment based on morphological and T2 signal changes is challenging and inaccurate [36, 37]. The addition of DWI and DCE MRI is useful in monitoring the treatment response by observing the cellular and perfusion modulation in the tumor microenvironment following CCRT [38, 39].
Physics of radiation therapy for the radiobiologist
Published in Michael C. Joiner, Albert J. van der Kogel, Basic Clinical Radiobiology, 2018
Jay W. Burmeister, Michael C. Joiner
External beam radiotherapy generally involves the delivery of a number of beams irradiating the treatment target from different directions. The gantry, collimator and treatment couch are all designed to rotate to allow flexibility in the direction in which the radiation beams can be delivered. The point at which the axes of rotation of the gantry, collimator and couch intersect is called the ‘isocenter’. If the target is placed at the isocenter then any combination of gantry, collimator or couch angles will result in a beam traversing the target volume provided the beam is shaped with the collimator to match the target cross section in the beam's eye view. As such, most treatments are delivered ‘isocentrically’ to avoid the requirement of moving the patient between successive treatment fields. Generally, a set of lasers is mounted in the room and used to indicate the location of the isocenter for patient positioning and alignment.
A Case Report of Conjunctival Extranodal Marginal Zone Lymphoma Treated with Intralesional Rituximab Injection Therapy
Published in Ocular Immunology and Inflammation, 2022
Titap Yazicioglu, Murat Oklar, Seyhan Kocabas, Erdi Karadag, Vildan Elibol, Mehmet Engin Tezcan
Low-grade EMZL is the most common form of conjunctival lymphomas. Other frequent types of conjunctival lymphomas are follicular, diffuse large B cell and mantle cell lymphoma, respectively.6 The treatment of conjunctival lymphomas was decided depending on the systemic involvement and local spread of the disease. External beam radiotherapy, systemic immunotherapy (interferon, mitomycin C) or chemotherapy, excisional biopsy or observation are the treatment options on conjunctival lymphoma. Rituximab, a monoclonal antibody targeting the B lymphocyte surface antigen CD20, has been used intravenously, intralesional and intravitreally to treat ocular adnexal and primary intraocular lymphomas. To our knowledge, there are few reported cases of low-grade conjunctival lymphoma treated with intralesional rituximab.7,8 External beam radiotherapy, the gold standard treatment method for conjunctival lymphomas,9 provides 85% −100% local control even in the presence of systemic disease.10 However, short and long-term complications can be seen in up to 50% of patients due to radiotherapy. The most frequent side effects of external beam radiotherapy are eyelid irritation, mild conjunctivitis, dry eye syndrome, radiation retinopathy, cataracts, orbital adipose tissue atrophy, and corneal ulceration.11
Effects of I-125 seeds combined with anlotinib on tumor growth and bone metabolism in A549 tumor-bearing mice
Published in International Journal of Radiation Biology, 2021
Feilong He, Qi Bao, Jiangtao Bai, Jianping Wang, Jianglong Zhai, Qiquan Yu, Wentao Guo, Chunxiao Wu, Kun Zhang, Weizhen Shou, Guoying Zhu
As we know, clinical radiotherapy treats life-threatening cancers, but the radiation often affects neighboring normal tissues including bone, and bone health is an important parameter to monitor the comorbidities during radiotherapy, chemotherapy, glucocorticoids and tyrosine kinase inhibitors treatment (Body et al. 2016; Handforth et al. 2018). Conventional external beam radiotherapy has been proved to be an important and effective strategy for the treatment of malignancies; however, bone tissue within the irradiation region could also absorb radiation and have an increased risk of fracture (Willey et al. 2011; D'Oronzo et al. 2015; Body et al. 2016). This study hypothesized that radioactive I-125 seed implantation brachytherapy could be less deterioration in bone quality than seen with traditional focal external-beam radiotherapy due to the shorter track length of β rays. To our knowledge, this is the first study focusing on the impact of I-125 seeds implantation on bone. Importantly, this study proved that I-125 seeds implantation did not further deteriorate the bone metabolism balance, which is helpful to maintain the bone quality. Meanwhile, a relatively intact bone metabolism, as indicated by the decrease of TRAP-positive cells and TRAP activity, was identified in fractionated IM, single IM and single IM + anlotinib treatment groups. In addition, ALP expression and PINP level increased after I-125 seeds irradiation. In conclusion, different from external beam radiotherapy, I-125 seeds implantation has less impact on the bone tissue.
Therapeutic Changes in Bilateral Choroidal Metastasis from Non-Small Cell Lung Cancer with Response to Afatinib: A Case Report
Published in Ocular Immunology and Inflammation, 2020
Han Peng Zhou, Rie Tanaka, Hideki Tsuji
Conventional treatments for choroidal metastasis of NSCLC include systemic chemotherapy used alone or in combination with local therapy.4 Systemic agents are able to diffuse freely into the metastatic lesion since the choroids are external to the blood-retinal barrier. However, cytotoxic effects of chemotherapy often result in a wide variety of systemic adverse effects such as hair loss, diarrhea, stomatitis, and myelosuppression.4 Exacerbation of these side effects may cause the early discontinuation of the treatment, leading to poor prognosis. Local therapy such as external beam radiotherapy is also effective and is sometimes used in combination with chemotherapy.3 However, patients receiving radiotherapy are often at risk for visually compromising adverse effects such as radiation retinopathy, papillopathy, cataract, exposure keratopathy, and iris neovascularization.3,4