A concise review of immunotherapy for glioblastoma

Glioblastoma (GB) is the most common and aggressive form of primary brain tumors in adults with a universally poor prognosis despite multimodal management including surgery, chemotherapy and radiation therapy. Among the novel therapeutic strategies, immunotherapy deserves particular attention with its potential to evoke biologic response and harness the host immune system. Considerable success achieved for other tumors has elicited great enthusiasm and prompted research on immunotherapy for GB. While the central nervous system has traditionally been thought of as an immune-privileged site, our understanding is being refined with emerging evidence. Several studies have been conducted and more are under way to establish the role of immunotherapy in management of GB. Immunotherapy of GB has yet resulted in mixed success with conflicting research findings, emphasizing the need for extensive study before its integration into routine clinical practice. Although there is a lot of room for improvement, immunotherapy for GB may be feasible and serve as a viable management strategy broadening and strengthening the therapeutic armamentarium to combat this deadly disease. Herein, we present a concise review of immunotherapy for GB

A Concise Review of Pelvic Radiation Therapy (RT) for Rectal Cancer with Synchronous Liver Metastases

Background and Objective. Colorectal cancer is a major health concern as a very common cancer and a leading cause of cancer-related mortality worldwide. The liver is a very common site of metastatic spread for colorectal cancers, and, while nearly half of the patients develop metastases during the course of their disease, synchronous liver metastases are detected in 15% to 25% of cases. There is no standardized treatment in this setting and no consensus exists on optimal sequencing of multimodality management for rectal cancer with synchronous liver metastases. Methods. Herein, we review the use of pelvic radiation therapy (RT) as part of potentially curative or palliative management of rectal cancer with synchronous liver metastases. Results. There is accumulating evidence on the utility of pelvic RT for facilitating subsequent surgery, improving local tumor control, and achieving palliation of symptoms in patients with stage IV rectal cancer. Introduction of superior imaging capabilities and contemporary RT approaches such as Intensity Modulated Radiation Therapy (IMRT) and Image Guided Radiation Therapy (IGRT) offer improved precision and toxicity profile of radiation delivery in the modern era. Conclusion. Even in the setting of stage IV rectal cancer with synchronous liver metastases, there may be potential for extended survival and cure by aggressive management of primary tumor and metastases in selected patients. Despite lack of consensus on sequencing of treatment modalities, pelvic RT may serve as a critical component of multidisciplinary management. Resectability of primary rectal tumor and liver metastases, patient preferences, comorbidities, symptomatology, and logistical issues should be thoroughly considered in decision making for optimal management of patients

Evaluation of critical organ dosimetry with focus on heart exposure in supine versus prone patient positioning for breast irradiation

Breast cancer (Ca) remains to be the most frequent cancer among females and a leading cause of cancer associated mortality worldwide. Main modalities for management of breast Ca include surgery, Radiation Therapy (RT), and systemic treatments. Diagnosis at earlier stages of breast Ca is increasing with rigorous utilization of screening and raised public awareness. Improvements in therapy contribute to longer life expectancies for patients with breast Ca. In this context, adverse radiation effects are being a more pronounced aspect of breast Ca management recently.While the adverse effects of irradiation in earlier studies may have led to unfavorable outcomes for some patients with breast Ca, toxicity profile of radiation delivery has been improved with introduction of modernized equipment and contemporary techniques such as Breathing Adapted Radiation Therapy (BART), Image Guided Radiation Therapy (IGRT), Intensity Modulated Radiation Therapy (IMRT) and Adaptive Radiation Therapy (ART). Individualized patient positioning has also been utilized for improved normal tissue sparing while maintaining target coverage. While the conflicting results of cardiac dosimetry among different studies may partly be explained by variations in delineation and treatment techniques between treatment centers, prone positioning may be considered for at least a selected group of breast Ca patients as a viable alternative to supine positioning. Herein, we evaluate critical organ dosimetry with focus on heart exposure in supine versus prone patient positioning for breast irradiation.&nbsp;&nbsp;</p

A concise review of irradiation sequelae on the cardiovascular system in pulmonary malignancies

Pulmonary malignancies including Small Cell Lung Cancer (SCLC) and Non-Small Cell Lung Cancer (NSCLC) are frequent cancers and remain to be a leading cause of cancer related mortality worldwide. Radiation Therapy (RT) has an integral role in management of both SCLC and NSCLC. It may be used as the single definitive modality, as part of curative combined modality management, and also for salvage treatment or recurrent disease settings in selected patients. Nevertheless, radiation induced toxicity constitutes an important concern in radiotherapeutic management of pulmonary malignancies. Among the adverse effects of pulmonary irradiation, radiation induced cardiotoxicity deserves utmost consideration. Several studies consistently underscore the importance of minimizing heart exposure as much as possible to avoid untowards cardiac morbidity and mortality.There have been substantial advances which contributed to improved radiotherapeutic management of SCLC and NSCLC including improved staging and target definition by incorporation of molecular imaging, automatic segmentation procedures, Image Guided Radiation Therapy (IGRT), Breathing Adapted Radiation Therapy (BART), Adaptive Radiation Therapy (ART), Intensity Modulated Radiation Therapy (IMRT). Nevertheless, there is room for further achievements. Proton therapy for management of lung cancer has been suggested as a relatively newer treatment modality with promising results. Unique characteristics of proton therapy may allow for improved cardiac sparing along with reduced integral dose. Future trials are warranted to shed light on contemporary management of pulmonary malignancies with optimal cardiac sparing and reduced irradiation sequelae. Herein, we provide a concise review of irradiation sequelae on the cardiovascular system in pulmonary malignancies.</p

Multimodality management of cavernous sinus meningiomas with less extensive surgery followed by subsequent irradiation: Implications for an improved toxicity profile

Meningiomas comprise the most frequent intracranial benign tumors accounting for approximately one third of all intracranial neoplasms, and generally follow an indolent disease course with a typically benign nature and slow-growing behaviour. Although majority of meningiomas may follow an indolent disease course, affected patients may suffer from a plethora of symptoms with regard to lesion location. Symptoms typically occur as a result of the mass effect leading to compression of critical neurovascular structures. Headache, focal seizures, weakness in the limbs, visual disturbances, loss of smell, impaired memory or hearing functions may be observed. Advances in neurosurgery may allow for an improved toxicity profile following surgical resection as the traditional and a leading mode of management for meningiomas located at accessible brain areas. Nevertheless, vigilance is required given the morbidity and mortality risks associated with meningioma surgery particularly for elderly patients. In this context, radiation therapy (RT) may offer a viable alternative or adjunctive modality of management for meningiomas. Management of cavernous sinus meningiomas in intricate association with critical neurovascular structures pose a formidable challenge to the treating physicians. Attempting at extensive surgical procedures may be associated with substantial morbidity and even mortality. In this context, selected patients may benefit from a tailored multimodality approach including less extensive surgical resection followed by subsequent irradiation. Primary advantages of this refined therapeutic strategy may include improved toxicity profile along with improved functionality and quality of life. Herein, we assess multimodality management of cavernous sinus meningiomas with less extensive surgery followed by subsequent irradiation.</p

Single Fraction Stereotactic Radiosurgery (SRS) versus Fractionated Stereotactic Radiotherapy (FSRT) for Vestibular Schwannoma (VS)

Vestibular schwannoma (VS), also referred to as acoustic neuroma, is one of the common benign intracranial tumors with rising incidence due to improved and more frequent neuroimaging. These common tumors of the cerebellopontine angle arise from the Schwann cells of vestibulocochlear nerve, and management with main therapeutic modalities of surgery and radiation therapy (RT) may be considered while observation is also an option for selected patients. Intervention may be required for VS although these slow growing tumors may follow an indolent disease course. Decision for management with a given modality should take into account several factors including lesion location, size, and closeness to critical structures, age, symptomatology, patient preferences, and logistical issues. RT has traditionally served as a viable treatment modality for VS management and radiosurgical applications in the forms of single fraction Stereotactic Radiosurgery (SRS) or Fractionated Stereotactic Radiotherapy (FSRT) have been utilized for treatment of patients. Selection of dose and fractionation is critical for safe and effective radiosurgical treatment of VS. Studies of SRS and FSRT for VS management consistently reported high tumor control rates with both modalities. It appears that smallerVS lesions are well suited for single dose SRS while FSRT may serve as an excellent treatment alternative for management of larger VS lesions particularly for improving the toxicity profile of treatment. Herein, we assess the use of single fraction SRS versus FSRT for management of VS in light of the literature with focus on recent trends and future perspectives.</p

Evaluation of Additional Sequential Boost Radiotherapy (RT) After Whole Breast Irradiation (WBI) for Patients with Early Breast Cancer (Ca)

Breast cancer (Ca) comprises the most common cancer in females and constitutes a leading cause of cancer related deaths around the globe. Contemporary treatment protocols established by incorporation of accumulating high level evidence suggest multimodality therapy for patients suffering from breast Ca with combinations of surgery, radiotherapy (RT) and systemic treatment. Surgical options for management of breast cancer typically include breast conserving surgery (BCS) or mastectomy. In current treatment practice, BCS is used as a viable surgical modality for breast Ca management. RT after BCS has been widely adopted for management of the vast majority of patients with breast Ca particularly to achieve improved local control as suggested by collaborative group studies and metaanalyses. Although alternative dose-fractionation schemes may be considered for management of some patients, current widely accepted practice includes the use of conventionally fractionated RT after BCS for breast Ca. Whole breast irradiation (WBI) constitutes a widely recognized breast Ca RT approach which is typically used to deliver a total dose of 45 to 50 Gy over 5 to 6 weeks in daily fractions of 1.8 to 2 Gy. Hypofractionated RT schemes have also been widely accepted as a viable alternative to conventional fractionation with satisfactory treatment outcomes. A typical location for local recurrences of breast Ca includes the primary tumor site within the tumor bed or its vicinity, which justifies the delivery of additional boost dose focused on this area to improve local control rates particularly for patients with high-risk characteristics including younger age, large tumor size, higher grade, extensive intraductal component, close or positive surgical margins. Herein, we assess the utility of delivering an additional sequential boost RT after WBI for patients with early breast Ca in light of the literature.</p

Review of dose fractionation schemes for pontine glioma irradiation

Brainstem tumors constitute approximately 10% to 15% of CNS neoplasms in the pediatric population, and most common of brainstem tumors is diffuse intrinsic pontine glioma (DIPG). Children with DIPG are typically diagnosed at the 5th to 10th years of their lives, with tumors being more frequently located in the pons rather than the midbrain or medulla oblongata. Symptomatology of patients may be severe and associated with compression of nuclei and tracts in the pons leading to cranial nerve dysfunctions. The wide spectrum of symptomatology may result in profound deterioration of the patients’ quality of life, and management is required for symptomatic relief. Complete removal of DIPG is typically not achievable given the diffuse and infiltrating nature of the disease with significant risk of excessive toxicity associated with surgical interventions. Nevertheless, surgical biopsy may be considered as a technically feasible procedure for selected patients to allow for histopathological verification and acquisition of biological data to aid in decision making for management. Utility of chemotherapy, biological and targeted therapies is being actively investigated as a promising treatment strategy, however, there is still room for improvement for routine clinical use. Radiation therapy (RT) remains to be a principal management approach for DIPG. Herein, we provide a concise review of dose fractionation schemes for pontine glioma irradiation.</p