OBJECTIVE: The PARCER trial provided level I evidence for image-guided intensity-modulated radiation therapy (IG-IMRT) in patients with cervical cancer. Further information regarding long-term financial impact is imperative for adoption into the National Cancer Grid of India cervical cancer resource-stratified guidelines.
METHODS: Patient data from the PARCER trial were analyzed to evaluate the cost implications of transitioning to IG-IMRT. Lacking differences in outcomes between the three-dimensional conformal radiation (3D-CRT) and IG-IMRT, differences in treatment costs, adverse event incidence, and toxicity management costs were examined. The overall financial impact was estimated by adding the treatment costs, toxicity management, and wage loss. This was extrapolated nationally to determine if a transition to IG-IMRT would be feasible for the Indian health care system.
RESULTS: Of the 300 patients in the PARCER trial, 93 faced grades ≥2 adverse events (3D-CRT = 59, IG-IMRT = 34). Patients in the 3D-CRT and IG-IMRT arms spent an average of 2.39 years and 1.96 years in toxicity, respectively. The average toxicity management and the yearly financial impact per patient were, respectively, 1.50 and 1.44 times higher for 3D-CRT patients compared with IG-IMRT patients. Extrapolation to the national level showed that treatment with 3D-CRT led to a 2.88 times higher cost ratio when compared with treatment with IG-IMRT.
CONCLUSIONS: Although the initial costs of IG-IMRT are high, on the basis of longitudinal data, it is financially inefficient to treat with 3D-CRT. Resource-stratified guidelines should include longitudinal health intervention costs rather than solely initial costs for policy decisions to implement advanced radiation technology.

OBJECTIVE: This guideline provides evidence-based recommendations on appropriate indications and techniques for partial breast irradiation (PBI) for patients with early-stage invasive breast cancer and ductal carcinoma in situ.
METHODS: ASTRO convened a task force to address 4 key questions focused on the appropriate indications and techniques for PBI as an alternative to whole breast irradiation (WBI) to result in similar rates of ipsilateral breast recurrence (IBR) and toxicity outcomes. Also addressed were aspects related to the technical delivery of PBI, including dose-fractionation regimens, target volumes, and treatment parameters for different PBI techniques. The guideline is based on a systematic review provided by the Agency for Healthcare Research and Quality. Recommendations were created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength.
RESULTS: PBI delivered using 3-dimensional conformal radiation therapy, intensity modulated radiation therapy, multicatheter brachytherapy, and single-entry brachytherapy results in similar IBR as WBI with long-term follow-up. Some patient characteristics and tumor features were underrepresented in the randomized controlled trials, making it difficult to fully define IBR risks for patients with these features. Appropriate dose-fractionation regimens, target volume delineation, and treatment planning parameters for delivery of PBI are outlined. Intraoperative radiation therapy alone is associated with a higher IBR rate compared with WBI. A daily or every-other-day external beam PBI regimen is preferred over twice-daily regimens due to late toxicity concerns.
CONCLUSIONS: Based on published data, the ASTRO task force has proposed recommendations to inform best clinical practices on the use of PBI.

The purpose of the first two editions of the guidelines for external radiotherapy procedures, published in 2007 and 2016 respectively, was to issue recommendations aimed at optimising, harmonising and standardising practices. The purpose of this third edition, which includes brachytherapy, is identical while also taking into account recent technological improvements (intensity modulation radiation therapy, stereotactic radiotherapy, and three-dimension brachytherapy) along with findings from literature. Part one describes the daily use of general principles (quality, security, image-guided radiation therapy); part two describes each treatment step for the main types of cancer.

For decades, radiotherapy with two opposing photon beams has been the standard technique used to cover the flank target volume in paediatric patients with renal tumours. Nowadays, many institutes are implementing advanced radiotherapy techniques that spare healthy tissue. To decrease the radiotherapy dose to healthy structures while preserving oncological efficacy, the conventional approach of flank irradiation has been adapted into a guideline for highly conformal flank target-volume delineation by paediatric radiation oncologists and representatives of the International Society of Paediatric Oncology\'s Renal Tumour Study Group (SIOP-RTSG) board during four live international consensus meetings. The consensus was refined by delineation exercises and videoconferences by ten collaborating paediatric radiation oncologists. The final guideline includes eight chronological steps to generate the tumour bed and clinical, internal, and planning target volumes, and it describes the optional use of surgical clips to optimise treatment planning. This guideline will be added into the radiotherapy guideline of the UMBRELLA SIOP-RTSG protocol for paediatric renal tumours to improve international consistency of highly conformal flank target-volume delineation.

Graves\' ophthalmopathy is the most common extra-thyroid manifestation in patients with Graves\' disease, based on inflammatory and autoimmune conditions in orbital tissue. This practical guideline was formed by a multidiciplinary team, and is intended to provide guidance for diagnosis and management of Graves\' ophthalmopathy in daily clinical practice to improve quality of care and treatment outcome.

UNASSIGNED: Along with breast-conserving surgery (BCS), adjuvant radiotherapy (RT) of patients with early breast cancer plays a crucial role in the oncologic treatment concept. Conventionally, irradiation is carried out with the aid of tangentially arranged fields. However, more modern and more complex radiation techniques such as IMRT (intensity-modulated radio therapy) are used more frequently, as they improve dose conformity and homogeneity and, in some cases, achieve better protection of adjacent risk factors. The use of this technique has implications for the incidental- and thus unintended- irradiation of adjacent loco regional lymph drainage in axillary lymph node levels I-III and internal mammary lymph nodes (IMLNs). A comparison of a homogeneous \"real-life\" patient collective, treated with helical tomotherapy (TT), patients treated with 3D conformal RT conventional tangentially arranged fields (3DCRT) and deep inspiration breath hold (3DCRT-DIBH), was conducted.
METHODS: This study included 90 treatment plans after BCS, irradiated in our clinic from January 2012 to August 2016 with TT (n = 30) and 3D-CRT (n = 30), 3DCRT DIBH (n = 30). PTVs were contoured at different time points by different radiation oncologists (> 7). TT was performed with a total dose of 50.4 Gy and a single dose of 1.8 Gy with a simultaneous integrated boost (SIB) to the tumor cavity (TT group). Patients irradiated with 3DCRT/3DCRT DIBH received 50 Gy à 2 Gy and a sequential boost. Contouring of lymph drainage routes was performed retrospectively according to RTOG guidelines.
RESULTS: Average doses (DMean) in axillary lymph node Level I/Level II/Level III were 31.6 Gy/8.43 Gy/2.38 Gy for TT, 24.0 Gy/11.2 Gy/3.97 Gy for 3DCRT and 24.7 Gy/13.3 Gy/5.59 Gy for 3DCRT-DIBH patients. Internal mammary lymph nodes (IMLNs) Dmean were 27.8 Gy (TT), 13.5 Gy (3DCRT), and 18.7 Gy (3DCRT-DIBH). Comparing TT to 3DCRT-DIBH dose varied significantly in all axillary lymph node levels and the IMLNs. Comparing TT to 3DCRT significant dose difference in Level I and IMLNs was observed.
CONCLUSIONS: Dose applied to locoregional lymph drainage pathways varies comparing tomotherapy plans to conventional tangentially arranged fields. Studies are warranted whether dose variations influence loco-regional spread and must have implications for target volume definition guidelines.

Ependymoma is an uncommon neuroepithelial tumor that may arise anywhere within the neuroaxis, both in children and in adults. It has been classically graded upon histopathological features, yet with limited clinical utility. Recently, DNA methylation profiling has provided a novel classification of ependymoma in nine molecular subgroups. This stratification method harbors prognostic value with supratentorial RELA-fusion and posterior fossa group A tumors showing a significantly shorter survival compared to the rest. Currently, the treatment of choice involves maximal safe resection and, in cases of residual disease, adjuvant conformal radiotherapy. Second-look surgery is also a feasible and recommended option for incompletely resected tumors. The role of chemotherapy is not yet established and can be considered in infants and children with relapsing disease or prior to re-intervention. Although targeted agents do not seem to play a role as adjuvant therapy, they are currently being tested for recurrent disease.

Inhomogeneities in radiotherapy dose distributions covering the vertebrae in children can produce long-term spinal problems, including kyphosis, lordosis, scoliosis, and hypoplasia. In the published literature, many often interrelated variables have been reported to affect the extent of potential radiotherapy damage to the spine. Articles published in the 2D and 3D radiotherapy era instructed radiation oncologists to avoid dose inhomogeneity over growing vertebrae. However, in the present era of highly conformal radiotherapy, steep dose gradients over at-risk structures can be generated and thus less harm is caused to patients. In this report, paediatric radiation oncologists from leading centres in 11 European countries have produced recommendations on how to approach dose coverage for target volumes that are adjacent to vertebrae to minimise the risk of long-term spinal problems. Based on available information, it is advised that homogeneous vertebral radiotherapy doses should be delivered in children who have not yet finished the pubertal growth spurt. If dose fall-off within vertebrae cannot be avoided, acceptable dose gradients for different age groups are detailed here. Vertebral delineation should include all primary ossification centres and growth plates, and therefore include at least the vertebral body and arch. For partial spinal radiotherapy, the number of irradiated vertebrae should be restricted as much as achievable, particularly at the thoracic level in young children (<6 years old). There is a need for multicentre research on vertebral radiotherapy dose distributions for children, but until more valid data become available, these recommendations can provide a basis for daily practice for radiation oncologists who have patients that require vertebral radiotherapy.

OBJECTIVE: The aim of this guideline is to present recommendations regarding moderately hypofractionated (240-340 cGy per fraction) and ultrahypofractionated (500 cGy or more per fraction) radiation therapy for localized prostate cancer.
METHODS: The American Society for Radiation Oncology convened a task force to address 8 key questions on appropriate indications and dose-fractionation for moderately and ultrahypofractionated radiation therapy, as well as technical issues, including normal tissue dose constraints, treatment volumes, and use of image guided and intensity modulated radiation therapy. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and Society-approved tools for grading evidence quality and recommendation strength.
RESULTS: Based on high-quality evidence, strong consensus was reached for offering moderate hypofractionation across risk groups to patients choosing external beam radiation therapy. The task force conditionally recommends ultrahypofractionated radiation may be offered for low- and intermediate-risk prostate cancer but strongly encourages treatment of intermediate-risk patients on a clinical trial or multi-institutional registry. For high-risk patients, the task force conditionally recommends against routine use of ultrahypofractionated external beam radiation therapy. With any hypofractionated approach, the task force strongly recommends image guided radiation therapy and avoidance of nonmodulated 3-dimensional conformal techniques.
CONCLUSIONS: Hypofractionated radiation therapy provides important potential advantages in cost and convenience for patients, and these recommendations are intended to provide guidance on moderate hypofractionation and ultrahypofractionation for localized prostate cancer. The limits in the current evidentiary base-especially for ultrahypofractionation-highlight the imperative to support large-scale randomized clinical trials and underscore the importance of shared decision making between clinicians and patients.

The objective of this project was to define consensus guidelines for delineating brainstem substructures (dorsal vagal complex, including the area postrema) involved in radiation-induced nausea and vomiting (RINV). The three parts of the brainstem are rarely delineated, so this study was also an opportunity to find a consensus on this subject.
The dorsal vagal complex (DVC) was identified on autopsy sections and endoscopic descriptions. Anatomic landmarks and boundaries were used to establish radio-anatomic correlations on CT and Magnetic Resonance Imaging (MRI). Additionally, delineation of RINV structures was performed on MRI images and reported on CT scans. Next, guidelines were provided to eight radiation oncologists for delineation guidance of these RINV-related structures on DICOM-RT images of two patients being treated for a nasopharyngeal carcinoma. Interobserver variability was computed.
The DVC and the three parts of the brainstem were defined with a concise description of their main anatomic boundaries. The interobserver analysis showed that the DVC, the midbrain, the pons, and the medulla oblongata delineations were reproducible with KI = 0.72, 0.84, 0.94 and 0.89, respectively. The Supplemental Material section provides an atlas of the consensus guidelines projected on 1-mm MR axial slices.
This RINV-atlas was feasible and reproducible for the delineation of RINV structures on planning CT using fused MRI. It may be used to prospectively assess dose-volume relationship for RINV structures and occurrence of nausea vomiting during intracranial or head and neck irradiation.