Latest Research News on Radiation Oncology: Dec 2020
Radiation oncology: a century of achievements
Over the twentieth century the discipline of radiation oncology has developed from an experimental application of X-rays to a highly sophisticated treatment of cancer. Experts from many disciplines — chiefly clinicians, physicists and biologists — have contributed to these advances. Whereas the emphasis in the past was on refining techniques to ensure the accurate delivery of radiation, the future of radiation oncology lies in exploiting the genetics or the microenvironment of the tumour to turn cancer from an acute disease to a chronic disease that can be treated effectively with radiation. 
Charged particles in radiation oncology
Radiotherapy is one of the most common and effective therapies for cancer. Generally, patients are treated with X-rays produced by electron accelerators. Many years ago, researchers proposed that high-energy charged particles could be used for this purpose, owing to their physical and radiobiological advantages compared with X-rays. Particle therapy is an emerging technique in radiotherapy. Protons and carbon ions have been used for treating many different solid cancers, and several new centers with large accelerators are under construction. Debate continues on the cost:benefit ratio of this technique, that is, on whether the high costs of accelerators and beam delivery in particle therapy are justified by a clear clinical advantage. This Review considers the present clinical results in the field, and identifies and discusses the research questions that have resulted with this technique. 
Tumor microenvironmental physiology and its implications for radiation oncology
The microenvironmental physiology of tumors is uniquely different from that of normal tissues. It is characterized, inter alia, by O2 depletion (hypoxia, anoxia), glucose and energy deprivation, high lactate levels, and extracellular acidosis, parameters that are anisotropically distributed within the tumor mass. This hostile microenvironment is largely dictated by the abnormal tumor vasculature and heterogeneous microcirculation. Hypoxia and other hostile microenvironmental parameters are known to directly or indirectly confer resistance to irradiation leading to treatment failure. Hypoxia directly leads to a reduced “fixation” of radiation-induced DNA damage. Indirect mechanisms include a restrained proliferation, changes in gene expression and alterations of the proteome (eg, elevated activity of DNA-repair enzymes and resistance-related proteins, increased transcription of growth factors), and genomic changes (genomic instability leading to clonal heterogeneity and selection of resistant clonal variants). These changes, caused by the hostile microenvironment, can favor tumor progression and acquired treatment resistance, both resulting in poor clinical outcome and prognosis. Pretreatment assessment of critical microenvironmental parameters is therefore needed to allow the selection of patients who could benefit from special treatment approaches (eg, hypoxia-targeting therapy). Because of a relatively high risk of local relapse or distant metastasis, patients with hypoxic and/or “high-lactate” tumors should undergo close surveillance. 
Carotid Body Tumour a Challenging Management: Rare Case Report in Baghdad Radiation Oncology Center, Medical City, Baghdad, Iraq
Background: Paragangliomas are rare asymptomatic painless tumours, originating from paraganglionic bodies of autonomous nerve system. The carotid body tumours are the relatively rare tumour but constitute a majority of head and neck paragangliomas about 70%. These tumours are benign but possess aggressive local growth potential.
The Aim of the Study: The purpose of this case report article is to introduce the challenging we exposed to it during management such cases in our country despite lack many conditions, facilities and circumstances found in other parts of the world for treatment of CBT, which is the first time study in Iraq.
Case Presentation: We reported a case of the 27-year-old female patient with a left neck swelling that had persisted for 5 years. She was first diagnosed and treated surgically by local excision in 2012. Histopathology revealed the histology of carotid body tumour. She has complained of hypertension, headache, and palpitation. She was observed the gradual onset of growing and pulsating lump on previous surgical scar site. Five years later, the lesion became larger, and she feeling pulsation on lying on left side resulting in discomfort on sleep and deglutition. On physical examination, a pulsating firm painless mass measuring about 6 x 5 x 4 cm in size was found on the left side of her neck. Pulsations were felt on deep palpation and a faint bruit was heard on auscultation. Work up done for her included laboratory tests, neck US, neck CT scan, carotid angiography and slide review of histopathology. All suggested recurrent carotid body tumour.
Conclusion: Over forty years of working in this field, we have only seen 3 cases of CBTs, so it is a very rare tumour. Management of this tumour is a challenging whether it is treated by surgery or radiotherapy. The main step in management is by excluding others tumours can be found in this region. Surgery is a treatment of choice while radiotherapy is standard treatment for recurrent cases. 
Granulocytic Sarcoma of Ovary Associated with Chronic Myelogenous Leukaemia Mimicking Carcinoma: A Rare Case Report
Granulocytic sarcoma is a rare haematological neoplasm due to extramedullary leukemic deposits. Granulocytic Sarcoma of ovary is even rare associated with chronic myeloid leukaemia and responds to imatinib treatment. A strong vigilance is required. Here we report a case of granulocytic sarcoma of ovary in a 31 year old female with primary infertility being provisionally diagnosed as ovarian tumour. Later on, after complete haematological investigation and fine needle aspiration cytology of ovarian tumour, the case is found to be of granulocytic sarcoma associated with chronic myeloid leukaemia. The aim of documenting this case report is to establish the possibility of granulocytic sarcoma in unusual site which was initially thought to be of nonhematological malignancy and proved by tissue diagnosis to be of haematological malignancy. 
 Bernier, J., Hall, E.J. and Giaccia, A., 2004. Radiation oncology: a century of achievements. Nature Reviews Cancer, 4(9), pp.737-747.
 Durante, M. and Loeffler, J.S., 2010. Charged particles in radiation oncology. Nature reviews Clinical oncology, 7(1), pp.37-43.
 Vaupel, P., 2004, July. Tumor microenvironmental physiology and its implications for radiation oncology. In Seminars in radiation oncology (Vol. 14, No. 3, pp. 198-206). WB Saunders.
 J. Al-Rawaq, K., A. Al-Naqqash, M., S. Al-Shewered, A. and F. Al-Awadi, A. (2018) “Carotid Body Tumour a Challenging Management: Rare Case Report in Baghdad Radiation Oncology Center, Medical City, Baghdad, Iraq”, Journal of Cancer and Tumor International, 7(3), pp. 1-6. doi: 10.9734/JCTI/2018/40034.
 Samanta, D., Kumar Sahoo, T., Roopesh, K., Ranjan Mohanty, K., Bose, C. and Nath Senapati, S. (2015) “Granulocytic Sarcoma of Ovary Associated with Chronic Myelogenous Leukaemia Mimicking Carcinoma: A Rare Case Report”, Journal of Cancer and Tumor International, 3(2), pp. 1-5. doi: 10.9734/JCTI/2016/22486.