Radiation dose escalation and acceleration improves local control but also increases toxicity. Proton radiation is an emerging therapy for localized cancers that is being sought with increasing frequency by patients. Compared with photon therapy, proton therapy spares more critical structures due to its unique physics. The physical properties of a proton beam make it ideal for clinical applications. By modulating the Bragg peak of protons in energy and time, a conformal radiation dose with or without intensity modulation can be delivered to the target while sparing the surrounding normal tissues. Thus, proton therapy is ideal when organ preservation is a priority. However, protons are more sensitive to organ motion and anatomy changes compared with photons. In this article, we review practical issues of proton therapy, describe its image-guided treatment planning and delivery, discuss clinical outcome for cancer patients, and suggest challenges and the future development of proton therapy.
Carcinoma, Hepatocellular ; radiotherapy ; Female ; Four-Dimensional Computed Tomography ; Head and Neck Neoplasms ; radiotherapy ; Humans ; Liver Neoplasms ; radiotherapy ; Lung Neoplasms ; radiotherapy ; Male ; Neoplasms ; radiotherapy ; Photons ; therapeutic use ; Prostatic Neoplasms ; radiotherapy ; Protons ; therapeutic use ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted ; methods ; Radiotherapy, Intensity-Modulated ; methods ; Uterine Cervical Neoplasms ; radiotherapy

Esophageal cancer is the 7th leading cause of cancer deaths worldwide. While squamous cell carcinoma is the most prevalent histology internationally, adenocarcinoma of the distal esophagus accounts for nearly 50% of cases in developed countries due to the differences in the etiologic factors such as gastroesophageal reflux disease (GERD) and obesity that predominate. While surgery is the mainstay of treatment of this disease, the utilization of chemoradiation, either used postoperatively or neoadjuvantly, has become a standard practice in the United States. What is the optimal management approach is still an area of contention, however, and may be different in different regions around the world. This article reviews some of these controversies, including the role for surgery in patients treated with definitive chemoradiation. At the end, we will also outline recommendations regarding radiotherapy procedures and techniques.
Adenocarcinoma ; diagnosis ; epidemiology ; pathology ; therapy ; Carcinoma, Squamous Cell ; diagnosis ; epidemiology ; pathology ; therapy ; Chemoradiotherapy ; Esophageal Neoplasms ; diagnosis ; epidemiology ; pathology ; therapy ; Esophagectomy ; methods ; Humans ; Neoplasm Recurrence, Local ; Neoplasm Staging ; Risk Factors

Lung cancer is the leading cause of cancer death worldwide as well as in China. For many years, conventional oncologic treatments such as surgery, chemotherapy, and radiotherapy (RT) have dominated the field of non-small cell lung cancer (NSCLC). The recent introduction of immunotherapy in clinical practice, led to a paradigm shift in lung cancer as in many other solid tumors. Recent pre-clinical and clinical data have shown RT may also modify antitumor immune responses through induction of immunogenic cell death and reprogramming of the tumor microenvironment. This has led many to reexamine RT as a partner therapy to immuno-oncology treatments and investigate their potential synergy in an exponentially growing number of clinical trials. Clinical trials combining radiotherapy and immunotherapy are attracting major attention, experts were invited to discuss frontier and controversial academic topics: (1) Recent developments of clinical synergy between radiation and immune checkpoint inhibitors (ICIs) in the treatment of NSCLC; (2) Will immunotherapy and radiotherapy increase the toxicity risk for cancer patients; (3) How to cope the mixed responses/disassociated responses phenomenon in checkpoint inhibition therapy to NSCLC with local ablative therapy; (4) Combining radiotherapy and immunotherapy in the treatment of NSCLC brain metastases.