Jonathan W. Lischalk

Stereotactic Body Radiation Therapy for Localized Prostate Cancer.

AbstractStereotactic body radiation therapy (SBRT) has become a viable treatment option for the many patients who receive a diagnosis of localized prostate cancer each year. Technological advancements have led to tight target conformality, allowing for high-dose-per-fraction delivery without untoward normal tissue toxicity. Biochemical control, now reported up to 5 years, appears to compare favorably with dose-escalated conventionally fractionated radiotherapy. Moreover, toxicity and quality of life follow-up data indicate genitourinary and gastrointestinal toxicities are likewise comparable to conventional radiation therapy. Nevertheless, because of the long natural history of prostate cancer, extended follow-up will be necessary to confirm these impressive initial results. Within this prostate SBRT review, we explore the detailed rationale for SBRT treatment, the diverse SBRT techniques utilized and their unique technical considerations, and finally data for SBRT clinical efficacy and treatment-related toxicity.

Radiation therapy for hepatobiliary malignancies

Hepatobiliary malignancies represent a heterogeneous group of diseases, which often arise in a background of underlying hepatic dysfunction complicating their local management. Surgical resection continues to be the standard of care for hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC); unfortunately the majority of patients are inoperable at presentation. The aggressiveness of these lesions makes locoregional control of particular importance. Historical experience with less sophisticated radiotherapy resulted in underwhelming efficacy and oftentimes prohibitive liver toxicity. However, with the advent of extremely conformal and precise radiotherapy delivery, dose escalation to the tumor with sparing of surrounding normal tissue has yielded notable improvements in efficacy for this modality of treatment. Dose escalation has come in a variety of forms most notably as stereotactic body radiation therapy (SBRT) and hypofractionated proton therapy. As radiation techniques continue to improve, their proper incorporation into the local management of hepatobiliary malignancies will be paramount in improving the prognosis of what is a grave diagnosis.

From Röntgen Rays to Carbon Ion Therapy: The Evolution of Modern Radiation Oncology in Germany.

Beginning with the discovery of X-rays in 1895, German scientists and clinicians were instrumental in establishing the fields of diagnostic and therapeutic radiology, creating the first radiotherapy peer-reviewed journal, and holding the first international oncologic conference. These landmark achievements profoundly influenced the nascent field of radiation oncology. However, the rapid early scientific progress was first halted by World War I, derailed during World War II, and was slowly reestablished amid the divisions of the Cold War. Figure 1 chronicles many radiotherapy milestones during these distinct periods. Today, Germany has reemerged as a scientific leader in the field of radiotherapy, and a pioneer in basic radiobiology research and clinical implementation of particle therapy. Here we explore the technical advances as well as the clinical evolution of radiotherapy in Germany from the groundbreaking establishment of Bismarck’s healthcare system to a modern view of radiotherapy practice.

Overview of Toxicity Outcomes with Prostate SBRT and Comparison to Other Treatment Interventions (Urinary, Rectal and Sexual Outcomes)

Prostate cancer is the most common cancer diagnosis amongst adult males in the United States, with approximately 160,000 new diagnoses per year in the United States. Treatment of this disease may be associated with genitourinary, gastrointestinal, and sexual adverse effects. Stereotactic body radiation therapy (SBRT) has recently gained acceptance as an effective treatment modality, although concerns have been voiced over a potentially increased risk of toxicity given the high dose-per-fraction regimens employed. Fortunately, a wealth patient-reported outcome (PRO) data, in addition to standard physician-scored toxicity, is available from single and multi-institutional reports. This chapter will review the adverse effects that have been reported following SBRT, provide guidelines for prevention and management of symptoms, and compare these outcomes with those achieved by other treatment methods.

First Annual Report of the Resident Committee of the American College of Radiation Oncology

The American College of Radiation Oncology (ACRO) Resident Committee (RC) was established to provide meaningful educational content, professional development, and opportunities for service within the United States radiation oncology resident community. The goals of the RCmirror those of the ACROmission at large to Bpromote success in the practice of radiation oncology through education, responsible socioeconomic advocacy, and integration of science and technology into clinical practice.^ The ACRO Board of Chancellors has given marked independence to the ACRO RC to explore and implement a resident-focused agenda, which has allowed great ideas to flourish into full-fledged national programs. The RC has worked diligently to improve resident quality of life and education through the creation and implementation of distinct subcommittees within the RC, which include the following: membership, mentorship, research, scholarship, and scientific. Over the past year, the ACRO RC has developed and implemented a variety of projects; here, we report the results of the 2016–2017 academic year.

Definitive hypofractionated radiation therapy for early stage breast cancer: Dosimetric feasibility of stereotactic ablative radiotherapy and proton beam therapy for intact breast tumors

Purpose Few definitive treatment options exist for elderly patients diagnosed with early stage breast cancer who are medically inoperable or refuse surgery. Historical data suggest very poor local control with hormone therapy alone. We examined the dosimetric feasibility of hypofractionated radiation therapy using stereotactic ablative radiotherapy (SABR) and proton beam therapy (PBT) as a means of definitive treatment for early stage breast cancer. Methods and Materials Fifteen patients with biopsy-proven early stage breast cancer with a clinically visible tumor on preoperative computed tomography scans were identified. Gross tumor volumes were contoured and correlated with known biopsy-proven malignancy on prior imaging. Treatment margins were created on the basis of set-up uncertainty and image guidance capabilities of the three radiation modalities analyzed (3-dimensional conformal radiation therapy [3D-CRT], SABR, and PBT) to deliver a total dose of 50 Gy in 5 fractions. Dose volume histograms were analyzed and compared between treatment techniques. Results The median planning target volume (PTV) for SABR, PBT, and 3-dimensional CRT was 11.91, 21.03, and 45.08 cm3, respectively, and were significantly different (P < .0001) between treatment modalities. Overall target coverage of gross tumor and clinical target volumes was excellent with all three modalities. Both SABR and PBT demonstrated significant dosimetric improvements, each in its own unique manner, relative to 3D-CRT. Dose constraints to normal structures including ipsilateral/contralateral breast, bilateral lungs, and heart were all consistently achieved using SABR and PBT. However, skin or chest wall dose constraints were exceeded in some cases for both SABR and PBT plans and was dictated by the anatomic location of the tumor. Conclusions Definitive hypofractionated radiation therapy using SABR and PBT appears to be dosimetrically feasible for the treatment of early stage breast cancer. The anatomical location of the tumor relative to the skin and chest wall appears to be the primary limiting dosimetric factor.

Four-dimensional computed tomography prediction of inter- and intrafractional upper gastrointestinal tumor motion during fractionated stereotactic body radiation therapy

PURPOSE Respiratory-induced tumor motion of upper gastrointestinal (GI) tumors during radiation therapy is often assessed using a single 4-dimensional computed tomography (4D-CT) and presumed to be representative during fractionated treatment regimens. The purpose of this study was to examine the intra- and interfraction correlations of tumor motion between pretreatment 4D-CT and real-time fiducial-based motion tracking in patients treated with fractionated stereotactic body radiation therapy (SBRT) for upper GI malignancies. METHODS AND MATERIALS Fourteen patients with upper GI tumors underwent fractionated SBRT using the CyberKnife radiosurgical system with Synchrony respiratory motion management. Before treatment, each patient underwent a free-breathing 4D-CT scan and fiducial motion was tracked for each phase of the respiratory cycle. Real-time fiducial positions recorded during delivery of each SBRT fraction were extracted from the CyberKnife planning system. Displacements were compared between those predicted by 4D-CT and those recorded by Synchrony during treatment in the left-right (LR), anteroposterior (AP), and superoinferior (SI) directions. RESULTS The 4D-CT scans demonstrated little correlation with real-time mean fiducial displacement as determined by Pearson correlation with coefficients of 0.45, 0.52, and 0.63 in the SI, AP, and LR directions, respectively. Cohort-averaged maximum fiducial displacements based on 4D-CT and real-time tracking were measured to be 3.86 ± 1.40 mm versus 10.73 ± 7.03 mm, 2.29 ± 1.02 mm versus 4.44 ± 3.33 mm, and 1.45 ± 0.49 mm versus 2.67 ± 2.49 mm in the SI, AP, and LR directions, respectively. Mean fiducial displacements were greater than that predicted by the maximum displacements on the corresponding 4D-CT scan in 39%, 22%, and 25% of SBRT fractions in the SI, AP, and LR directions, respectively. CONCLUSIONS Comparison of 4D-CT with real-time fiducial tracking demonstrated significant inter- and intrafractional discrepancies, particularly in the SI direction, which could result in compromise of target coverage when planning with a single free-breathing 4D-CT.