Scott R. Silva

Image-Based Brachytherapy for the Treatment of Cervical Cancer

Cervical cancer is a disease that requires considerable multidisciplinary coordination of care and labor in order to maximize tumor control and survival while minimizing treatment-related toxicity. As with external beam radiation therapy, the use of advanced imaging and 3-dimensional treatment planning has generated a paradigm shift in the delivery of brachytherapy for the treatment of cervical cancer. The use of image-based brachytherapy, most commonly with magnetic resonance imaging (MRI), requires additional attention and effort by the treating physician to prescribe dose to the proper volume and account for adjacent organs at risk. This represents a dramatic change from the classic Manchester approach of orthogonal radiographic images and prescribing dose to point A. We reviewed the history and currently evolving data and recommendations for the clinical use of image-based brachytherapy with an emphasis on MRI-based brachytherapy.

The integration of radiation therapy and immunotherapy in melanoma management

Melanoma has long been considered an “immunologic” malignancy because of numerous reports of spontaneous regression as well as abscopal phenomena along with its relative responsiveness to cancer immunotherapy. Over the past few years, there has been a resurgence of interest in cancer immunotherapy with particular focus on melanoma. Many new immunotherapeutic interventions have arisen, some with notable clinical efficacy. One such example is the current generation of checkpoint inhibitors. In this article, we shall review the recent data on checkpoint inhibition in melanoma along with a brief review of other immunotherapeutic approaches, including the encouraging and expanding role of radiation therapy in integrated immunotherapy.

Low-dose total body irradiation: an overlooked cancer immunotherapy technique

Low-dose total body irradiation (LD-TBI) has been shown to be an effective therapy for patients with hematologic malignancies. The application of this method has fallen out of favor as newer systemic therapies have been developed. Nevertheless, for management of many of these hematologic malignancies, no prospective randomized trial has shown that any other treatment is unequivocally superior to LD-TBI. The precise mechanism of action is uncertain but it is believed by some to be at least partly immunologically mediated. In this review, we shall discuss the clinical data on this method along with some new potential applications. We also discuss some of the potential immunological mechanisms behind LD-TBI and consider future possibilities.

Clinical Application of a Hybrid RapidArc Radiotherapy Technique for Locally Advanced Lung Cancer

Objective: Radiation treatment planning for locally advanced lung cancer can be technically challenging, as delivery of ≥60 Gy to large volumes with concurrent chemotherapy is often associated with significant risk of normal tissue toxicity. We clinically implemented a novel hybrid RapidArc technique in patients with lung cancer and compared these plans with 3-dimensional conformal radiotherapy and RapidArc-only plans. Materials/Methods: Hybrid RapidArc was used to treat 11 patients with locally advanced lung cancer having bulky mediastinal adenopathy. All 11 patients received concurrent chemotherapy. All underwent a 4-dimensional computed tomography planning scan. Hybrid RapidArc plans concurrently combined static (60%) and RapidArc (40%) beams. All cases were replanned using 3- to 5-field 3-dimensional conformal radiotherapy and RapidArc technique as controls. Results: Significant reductions in dose were observed in hybrid RapidArc plans compared to 3-dimensional conformal radiotherapy plans for total lung V20 and mean (−2% and −0.6 Gy); contralateral lung mean (−2.92 Gy); and esophagus V60 and mean (−16.0% and −2.2 Gy; all P < .05). Contralateral lung doses were significantly lower for hybrid RapidArc plans compared to RapidArc-only plans (all P < .05). Compared to 3-dimensional conformal radiotherapy, heart V60 and mean dose were significantly improved with hybrid RapidArc (3% vs 5%, P = .04 and 16.32 Gy vs 16.65 Gy, P = .03). However, heart V40 and V45 and maximum spinal cord dose were significantly lower with RapidArc plans compared to hybrid RapidArc plans. Conformity and homogeneity were significantly better with hybrid RapidArc plans compared to 3-dimensional conformal radiotherapy plans (P < .05). Treatment was well tolerated, with no grade 3+ toxicities. Conclusion: To our knowledge, this is the first report on the clinical application of hybrid RapidArc in patients with locally advanced lung cancer. Hybrid RapidArc permitted safe delivery of 60 to 66 Gy to large lung tumors with concurrent chemotherapy and demonstrated advantages for reduction in low-dose lung volumes, esophageal dose, and mean heart dose.

Lung Cancer and Other Thoracic Malignancies

Lung cancer is the deadliest malignancy in the United States, and much research has been dedicated over the last many decades to improve patient outcomes. Smoking cessation education, lung cancer screening, improved diagnostic and functional imaging, improved surgical and radiation techniques, multimodality therapy, and targeted biologic and immunologic therapy have all lead to earlier detection of lung cancer and improved treatment resulting in improvements in overall survival. There are still many controversies that exist within each of these many aspects in the diagnosis and treatment of lung cancer. This chapter is dedicated to the controversies that exist in the management and treatment of all aspects of lung cancer with additional discussion of the controversies regarding thymoma and malignant pleural mesothelioma.

Grade 3 radiation dermatitis in a patient with presumed latent actinic lichen planus

Radiation-induced skin injury ranges from acute dermatitis to chronic skin changes. Acute skin injury occurs during the course of radiation treatment and may take 1 to 3 months after the completion of radiation therapy to completely heal. Patients with mild acute dermatitis present with mild erythema, dry desquamation, pruritus, hyperpigmentation, and hair loss. Severe acute dermatitis is characterized by confluent moist desquamation, ulcers, hemorrhage, and necrosis. Chronic radiation-induced skin injury includes chronic fibrosis with associated skin breakdown and infection. The severity of radiation-induced skin toxicity depends on radiation factors (dose, fractionation, volume, and surface area) and patient-specific factors. Excessive skinfolds increase radiation-induced skin toxicity. Also, patients with poor nutrition status or a preexisting vascular condition or connective tissue disease have impaired wound healing and are at increased risk of skin toxicity. Actinic lichen planus is an autoimmune skin disease characterized by a violaceous papule rash. Here, we report the case of a patient with presumed latent actinic lichen planus treated with definitive radiation therapy who subsequently developed overt lichen planus and severe radiation dermatitis in the treatment fields.