Adam Raben, MD, Editor

Recent advances that have dramatically changed the landscape in the management of adult central nervous system (CNS) malignancies are reviewed by Drs Kemmerer and Shah. This includes emerging data challenging the need for comprehensive CNS radiotherapy after surgery for oligo-brain metastases in favorable selected cases, in which stereotactic body radiation therapy can be effectively utilized after surgery or as an alternative to spare patients from late cognitive and memory deficits, without compromising survival. Exciting new survival data with PCV chemotherapy redefine the standard of care for low- and intermediate-risk gliomas after gross total or subtotal resection. Finally, important genomic characterization of CNS primary tumors is exploding and is being incorporated into clinical trials for HG gliomas to improve outcomes after surgery and radiotherapy.

The recognition of HPV+16 cancers of the oropharynx as a distinct biologic disease, with a favorable prognosis, is discussed by Drs Yom, Mallen-St Clair, and Ha, where they review new deescalation strategies that combine advanced surgical robotic technology (transoral robotic surgery, TORS) with reduced dose and site radiotherapy, and alternatives to chemotherapy. Trials to determine if TORS can reduce late toxicity compared with a full course of radiotherapy in a younger population are underway and will be critical in defining new standards of care.

Several articles reflect emerging and novel use of advanced technology in the field of Radiation Oncology that have resulted in an improved therapeutic ratio of cancers, such as lung and anus, and in the case of breast, shorter treatment courses that improve patient convenience and compliance. Maturing data presented in this issue now demonstrate meaningful opportunities to provide value-based care (reduced cost with improved or equipoise outcomes compared with protracted treatment courses) without compromising cancer-specific survival. Landmark trials reported in the last 5 years have demonstrated that prolonged courses of radiotherapy as part of breast conservation are not necessary for many patients, resulting in reduced cost, equivalent cosmesis and local control, and improved convenience. The article by Drs Castaneda and Strasser provides evidence of the rapid evolution of accelerated whole and partial breast radiotherapy techniques, with mature data for ductal carcinoma in situ and invasive disease that are changing the landscape of breast conservation management. The controversies regarding the value and efficacy of postmastectomy radiotherapy for locally advanced breast cancer are discussed by Drs Wright and Parekh, highlighted by review of landmark trials to give guidance to the surgical community.

This issue also updates the global adoption and effectiveness of stereotactic ablative radiotherapy (SABR) for non–small cell lung cancer. Advancements in image guidance, treatment planning systems, and improved spatial accuracy of treatment delivery have all converged to result in the effective use of SABR in the treatment of early-stage lung cancer. This paradigm-shifting approach allows significant reduction of treatment volumes, facilitating the use of high-dose radiation and increased biologic effective doses delivered to tumors. Drs Dan and Williams present compelling data demonstrating clinical equipoise between SABR and surgery for medically inoperable patients as well as a number of multi-institutional trials underway, investigating the direct comparison of SABR as an alternative to surgical resection.

For locally advanced esophageal cancer, trimodality treatment is now the new standard. Radiation with chemotherapy for locally advanced disease is suboptimal when surgery is omitted. Drs Shaikh, Meyer, and Horwitz reveal the results of the landmark CROSS trial, a contemporary well-designed phase 3 trial with modern staging, systemic chemotherapy, and radiotherapy resulting in a doubling of survival compared with surgery alone. Important biomarkers are expressed in esophageal cancer that may hold promise in improving survival. They reveal that nearly 20% of esophageal cancers have overexpression of HER2, a transmembrane tyrosine kinase receptor. Recent trials have shown improved survival with the addition of Trastuzumab, while new studies are underway to evaluate other mutations.

The changing landscape of management of pancreatic cancer over the last 4 years is presented by Dr Badiyan and colleagues. Current trials attempting to redefine the role of radiotherapy with systemic chemotherapy before or after surgery as well as its role in the unresectable setting and the controversy of its impact on survival are presented. In particular, the technological advance of SABT and image guidance to deliver equivalent local control in a shorter period of time without significant toxicity is practice changing.

Drs Castaneda and Romak update recent cooperative trials in anal cancer demonstrating the favorable role of intensity-modulated radiation therapy versus standard three-dimensional conformal radiotherapy in reducing significant acute and late-toxicity, risk adaptive-deescalation strategies combining local excision and lower radiotherapy stratified by margins in less advanced disease, and describe current areas of active research investigating the integration of biologic and immunotherapies in the treatment of ASCC.

Dr Stish and colleagues contribute an excellent summary of the long-term results of published brachytherapy experiences in the modern screening era for prostate cancer in both the favorable, intermediate, and high-risk setting that demonstrate improved risk group assessment, value-based care, and favorable outcomes in the high-risk setting when brachytherapy is added to external beam, based on exciting new data from a large phase 3 randomized trial that establishes a new standard of care.

Prospective multidisciplinary management of esophageal cancer, cervical cancer, and rectal/anal cancers has ushered in a greater cooperation and partnership between Radiation Oncologists, Surgeons, and Medical Oncologists.

Finally, Drs Ahmed, Kim, and Harrison articulate the emerging role and research of immunotherapies with radiation in the treatment of melanoma (that are now being applied to other malignancies), and why novel local delivery of radiation may be essential for systemic cancer cure.

I would like to thank Dr Nicholas Petrelli for the opportunity to participate as guest editor of this issue. I also would like to extend my sincere appreciation to the contributing authors, and the time and effort they gave into presenting such well-written and comprehensive articles, that I hope will be meaningful to our surgical colleagues.