-
The Lancet. Oncology Jan 2022High-quality randomised clinical trials testing moderately fractionated breast radiotherapy have clearly shown that local control and survival is at least as effective... (Review)
Review
European Society for Radiotherapy and Oncology Advisory Committee in Radiation Oncology Practice consensus recommendations on patient selection and dose and fractionation for external beam radiotherapy in early breast cancer.
High-quality randomised clinical trials testing moderately fractionated breast radiotherapy have clearly shown that local control and survival is at least as effective as with 2 Gy daily fractions with similar or reduced normal tissue toxicity. Fewer treatment visits are welcomed by patients and their families, and reduced fractions produce substantial savings for health-care systems. Implementation of hypofractionation, however, has moved at a slow pace. The oncology community have now reached an inflection point created by new evidence from the FAST-Forward five-fraction randomised trial and catalysed by the need for the global radiation oncology community to unite during the COVID-19 pandemic and rapidly rethink hypofractionation implementation. The aim of this paper is to support equity of access for all patients to receive evidence-based breast external beam radiotherapy and to facilitate the translation of new evidence into routine daily practice. The results from this European Society for Radiotherapy and Oncology Advisory Committee in Radiation Oncology Practice consensus state that moderately hypofractionated radiotherapy can be offered to any patient for whole breast, chest wall (with or without reconstruction), and nodal volumes. Ultrafractionation (five fractions) can also be offered for non-nodal breast or chest wall (without reconstruction) radiotherapy either as standard of care or within a randomised trial or prospective cohort. The consensus is timely; not only is it a pragmatic framework for radiation oncologists, but it provides a measured proposal for the path forward to influence policy makers and empower patients to ensure equity of access to evidence-based radiotherapy.
Topics: Advisory Committees; Breast Neoplasms; COVID-19; Consensus; Dose Fractionation, Radiation; Europe; Evidence-Based Medicine; Female; Humans; Patient Selection; Radiation Dose Hypofractionation; Radiation Oncology
PubMed: 34973228
DOI: 10.1016/S1470-2045(21)00539-8 -
Practical Radiation Oncology 2020Stereotactic body radiation therapy (SBRT) is increasingly used for nonspine bone metastases (NSBM); however, there are limited data informing treatment planning. We...
PURPOSE
Stereotactic body radiation therapy (SBRT) is increasingly used for nonspine bone metastases (NSBM); however, there are limited data informing treatment planning. We surveyed international experts to better understand worldwide practice patterns in delivering NSBM-SBRT.
METHODS AND MATERIALS
Nine international radiation oncologists were invited to participate based on demonstrated expertise with NSBM-SBRT. Experts were sent gross tumor volume contours and planning computed tomography and magnetic resonance images for 11 NSBM cases that covered a range of bony sites, including metastases to long bones (femur, humerus), pelvic bones (ilium, ischium, acetabulum, pubic symphysis), and thoracic bones (rib, sternum, scapula, clavicle). Experts were surveyed regarding treatment planning decisions and dose-fractionation selection. Descriptive analysis was conducted on the survey data.
RESULTS
All experts participated and completed the survey. Most (56%) routinely fused magnetic resonance imaging with planning computed tomography imaging for target delineation. Dose fractionation schedules included single-fraction (18-24 Gy/1), 2 fractions (24 Gy/2), 3 fractions (28-30 Gy/3), 5 fractions (30-50 Gy/5), and 10 fractions (42-50 Gy/10). Although doses varied considerably, all had a biological equivalent dose of ≤100 Gy. Five-fraction schedules were most common, specifically 35 Gy/5, with 56% opting for this dose-fractionation in at least 1 case. Other dose-fractionation schedules used by at least 3 experts were 20 Gy/1, 30 Gy/3, and 30 Gy/5. Three experts prescribed 2 dose volumes using a simultaneous integrated boost. The 2 dose volumes were either the gross tumor volume and clinical target volume (CTV) or a smaller CTV (CTV1) encompassed within a larger CTV (CTV2) (eg, 30 Gy/3 to gross tumor volume or CTV1 and 15-24 Gy/3 to CTV or CTV2). Dose de-escalation was recommended by all experts in the setting of previous SBRT and by most in the context of previous convevoltherapy or in weight-bearing bones, especially if moderate-to-severe cortical erosion was present.
CONCLUSIONS
Significant heterogeneity exists worldwide in radiation technique and dose-fractionation for NSBM-SBRT, which supports the need for consensus guidelines to inform practice and trial design. Nonetheless, these data demonstrate expert agreement on selecting dose schedules with a biologically effective dose ≤100 Gy, reasons for dose de-escalation, and in determining acceptable dose schedules based on bony site.
Topics: Bone Neoplasms; Dose Fractionation, Radiation; Humans; Magnetic Resonance Imaging; Radiosurgery; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted
PubMed: 32171852
DOI: 10.1016/j.prro.2020.02.011 -
Progress in Brain Research 2022New understandings of the biology of radiosurgery are considered. Differences from the radiobiology of fractionated radiotherapy are outlined. It is noted DNA damage...
New understandings of the biology of radiosurgery are considered. Differences from the radiobiology of fractionated radiotherapy are outlined. It is noted DNA damage alone is insufficient to account for the tissue changes which occur. Changes in blood vessels and immunological mechanisms are also involved. Tissue repair is more rapid than previously thought so that dose rate (the rate of delivery of radiation to the tissues) has been seen to be more important. The value of fractionation is examined. The effect of radiosurgery on normal brain (so called functional radiosurgery) is considered. The desired effects may be achieved by a focal stable destruction of brain from a high radiation dose. They may also be achieved using a lower dose which acts through the mechanism known as radiosurgical neuromodulation.
Topics: Brain; Dose Fractionation, Radiation; Humans; Radiobiology; Radiosurgery
PubMed: 35074083
DOI: 10.1016/bs.pbr.2021.10.024 -
Clinical Oncology (Royal College of... Jun 2021External beam radiotherapy (EBRT), as part of a trimodality approach, is an attractive bladder-preserving alternative to radical cystectomy. Several EBRT regimens with... (Review)
Review
External beam radiotherapy (EBRT), as part of a trimodality approach, is an attractive bladder-preserving alternative to radical cystectomy. Several EBRT regimens with different treatment volumes have been described with similar tumour control and, so far, clear recommendations on the optimal radiotherapy regimen and treatment volume are lacking. The current review summarises EBRT literature on dose prescription, fractionation as well as treatment volume in order to guide clinicians in their daily practice when treating patients with muscle-invasive bladder cancer. Taking into account literature on repopulation, continuous-course radiotherapy can be used safely in daily practice where a split-course should only be reserved for those patients who are fit enough to undergo a radical cystectomy in case of a poor early response. A recent meta-analysis has proven that hypofractionated radiotherapy is superior to conventional radiotherapy with regards to invasive locoregional control with similar toxicity profiles. In the absence of node-positive disease, the target volume can be restricted to the bladder. In order to compensate for organ motion, very large margins need to be applied in the absence of image-guided radiotherapy (IGRT). Therefore, the use of IGRT or an adaptive approach is recommended. Based on the available literature, one can conclude that moderate hypofractionated radiotherapy to a dose of 55 Gy in 20 fractions to the bladder only, delivered with IGRT, can be considered standard of care for patients with node-negative invasive bladder cancer.
Topics: Cystectomy; Dose Fractionation, Radiation; Humans; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Image-Guided; Urinary Bladder; Urinary Bladder Neoplasms
PubMed: 33832838
DOI: 10.1016/j.clon.2021.03.013 -
Breast (Edinburgh, Scotland) Nov 2019Progress in radiotherapy (RT) for early breast cancer, driven by advances in radiobiology and radiation techniques is enabling individualised target volume and... (Review)
Review
Progress in radiotherapy (RT) for early breast cancer, driven by advances in radiobiology and radiation techniques is enabling individualised target volume and dose-fractionation according to recurrence risk. Conventionally fractionated WBI (CF-WBI) has been justified on the basis that it spares dose-limiting late-responding normal tissues more than breast cancer. However, randomised clinical trials (RCTs) testing hypofractionated WBI (HF-WBI) showed equivalent tumour control, improved acute toxicity and similar late toxicity between selected HF-WBI schedules and CF-WBI. RCTs showed that tumour bed boost (TBB) after WBI improved local control but increased breast fibrosis compared to no TBB. RCT comparing sequential TBB and simultaneous integrated TBB using dose intensity modulation showed similar toxicity. Partial breast irradiation (PBI) limits target volume to the tumour bed, which permits safe treatment acceleration. RCTs showed that PBI resulted in low local relapse rates but in some RCTs, higher rates of late toxicity and adverse cosmetic outcome than WBI. Given heterogeneity of PBI techniques, target volumes and dose-fractionation schedules used in RCTs, interpretation of results to distinguish whether outcome variations are caused by target volume or dose-fractionation effect is challenging. RCTs demonstrating efficacy of post-mastectomy RT (PMRT) included the chest wall and regional nodes but did not distinguish relative contributions of nodal target sub-volumes. In patients with smaller axillary tumour burden, IMC irradiation is controversial. RCTs were not powered for comparison between CF-PMRT and HF-PMRT. No increase in arm or shoulder dysfunction with HF-PMRT was observed. No RCT data exist on HF-PMRT in patients with breast reconstruction.
Topics: Breast Neoplasms; Dose Fractionation, Radiation; Female; Humans; Mammaplasty; Mastectomy; Mastectomy, Segmental; Neoplasm Recurrence, Local; Postoperative Period; Radiotherapy, Adjuvant; Randomized Controlled Trials as Topic; Risk Assessment
PubMed: 31839165
DOI: 10.1016/S0960-9776(19)31128-2 -
Radiotherapy and Oncology : Journal of... Mar 2018The aim of this publication is to compile available literature data and expert experience regarding skin brachytherapy (BT) in order to produce general recommendations... (Review)
Review
PURPOSE
The aim of this publication is to compile available literature data and expert experience regarding skin brachytherapy (BT) in order to produce general recommendations on behalf of the GEC-ESTRO Group.
METHODS
We have done an exhaustive review of published articles to look for general recommendations.
RESULTS
Randomized controlled trials, systemic reviews and meta-analysis are lacking in literature and there is wide variety of prescription techniques successfully used across the radiotherapy centers. BT can be delivered as superficial application (also called contact BT or plesiotherapy) or as interstitial for tumours thicker than 5 mm within any surface, including very irregular. In selected cases, particularly in tumours located within curved surfaces, BT can be advantageous modality from dosimetric and planning point of view when compared to external beam radiotherapy. The general rule in skin BT is that the smaller the target volume, the highest dose per fraction and the shortest overall length of treatment can be used.
CONCLUSION
Skin cancer incidence is rising worldwide. BT offers an effective non-invasive or minimally invasive and relative short treatment that particularly appeals to elder and frail population.
Topics: Brachytherapy; Dose Fractionation, Radiation; Humans; Practice Guidelines as Topic; Radiotherapy Dosage; Skin Neoplasms
PubMed: 29455924
DOI: 10.1016/j.radonc.2018.01.013 -
Radiotherapy and Oncology : Journal of... Mar 1998Dose-volume histograms (DVHs) are often used in radiotherapy to provide representations of treatment dose distributions. DVHs are computed from physical dose and do not... (Review)
Review
BACKGROUND AND PURPOSE
Dose-volume histograms (DVHs) are often used in radiotherapy to provide representations of treatment dose distributions. DVHs are computed from physical dose and do not include radiobiological factors; therefore, the same DVH will be computed for a treatment plan whatever fractionation regimen is used. However, dose heterogeneity resulting from variation of daily treatment dose within the volume will have biological effects due to spatial heterogeneity of fraction size as well as total dose. The purpose of the paper is to present a radiobiological (LQ) transformation of the physical dose distribution which incorporates fraction size effects and may be better suited to the prediction of biological effects.
METHODS
An analytic formula is derived for the linear-quadratic transformation of a normal distribution of dose to give the corresponding distribution of biologically equivalent dose given as 2 Gy fractions. This allows LQ-transformed DVHs to be computed from physical DVHs. The resultant LQ-DVH depends on the assumed value of the relevant alpha/beta ratio. It is a modified dose distribution (corrected for spatial heterogeneity of fraction size) but does not incorporate time factors or volume effects.
RESULTS
The analysis shows that the LQ-transformed distribution is always broader than the distribution of physical dose. Radiobiological 'hot spots' and 'cold spots' are further from the mean than physical distributions would indicate. The difference between conventional DVHs and LQ-transformed DVHs is dependent on the fractionation regimen used. LQ-DVHs for a single dose distribution (treatment plan) can be computed for different fractionation regimens with some simplifying assumptions (e.g. no time-factor-dependence of late effects). Regimens calculated to be radiobiologically equivalent at a single point nevertheless result in non-equivalent LQ-DVHs when spatial variation of daily treatment dose is included. The difference is especially important for tumour sites (such as breast and head and neck) for which considerable dose heterogeneity may occur and for which different treatment regimens are in use.
CONCLUSIONS
LQ-DVHs should be computed in parallel with conventional DVHs and used in the evaluation of treatment plans and fractionation regimens and in the analysis of high-dose side-effects in patients.
Topics: Brachytherapy; Breast Neoplasms; Dose Fractionation, Radiation; Female; Humans; Linear Models; Mathematical Computing; Radiotherapy; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Sensitivity and Specificity
PubMed: 9572622
DOI: 10.1016/s0167-8140(97)00162-x -
Practical Radiation Oncology 2016To present evidence-based guidelines for radiation therapy in treating glioblastoma not arising from the brainstem.
PURPOSE
To present evidence-based guidelines for radiation therapy in treating glioblastoma not arising from the brainstem.
METHODS AND MATERIALS
The American Society for Radiation Oncology (ASTRO) convened the Glioblastoma Guideline Panel to perform a systematic literature review investigating the following: (1) Is radiation therapy indicated after biopsy/resection of glioblastoma and how does systemic therapy modify its effects? (2) What is the optimal dose-fractionation schedule for external beam radiation therapy after biopsy/resection of glioblastoma and how might treatment vary based on pretreatment characteristics such as age or performance status? (3) What are ideal target volumes for curative-intent external beam radiation therapy of glioblastoma? (4) What is the role of reirradiation among glioblastoma patients whose disease recurs following completion of standard first-line therapy? Guideline recommendations were created using predefined consensus-building methodology supported by ASTRO-approved tools for grading evidence quality and recommendation strength.
RESULTS
Following biopsy or resection, glioblastoma patients with reasonable performance status up to 70 years of age should receive conventionally fractionated radiation therapy (eg, 60 Gy in 2-Gy fractions) with concurrent and adjuvant temozolomide. Routine addition of bevacizumab to this regimen is not recommended. Elderly patients (≥70 years of age) with reasonable performance status should receive hypofractionated radiation therapy (eg, 40 Gy in 2.66-Gy fractions); preliminary evidence may support adding concurrent and adjuvant temozolomide to this regimen. Partial brain irradiation is the standard paradigm for radiation delivery. A variety of acceptable strategies exist for target volume definition, generally involving 2 phases (primary and boost volumes) or 1 phase (single volume). For recurrent glioblastoma, focal reirradiation can be considered in younger patients with good performance status.
CONCLUSIONS
Radiation therapy occupies an integral role in treating glioblastoma. Whether and how radiation therapy should be applied depends on characteristics specific to tumor and patient, including age and performance status.
Topics: Brain Neoplasms; Dose Fractionation, Radiation; Glioblastoma; Guidelines as Topic; Humans; Male; Prospective Studies; United States
PubMed: 27211230
DOI: 10.1016/j.prro.2016.03.007 -
Radiotherapy and Oncology : Journal of... Jun 2016Hypofractionated radiation therapy (RT) regimes in non-small cell lung cancer (NSCLC) have become increasingly popular with a number of international trials currently... (Review)
Review
Hypofractionated radiation therapy (RT) regimes in non-small cell lung cancer (NSCLC) have become increasingly popular with a number of international trials currently underway. The majority of the dose-volume-constraints (DVCs) published in the literature refer to conventional 2Gy per fraction deliveries. Here relevant organs-at-risk (OARs) are identified and available dose-volume constraint data discussed and summarised for moderately hypofractionated NSCLC regimes. The OARs examined include lung, brachial plexus, heart, oesophagus, airway and spinal cord. Where available the toxicity rates are also reported with all data summarised tabulated to aid its use in the clinic.
Topics: Brachial Plexus; Carcinoma, Non-Small-Cell Lung; Dose Fractionation, Radiation; Esophagus; Heart; Humans; Lung; Lung Neoplasms; Organs at Risk; Radiotherapy Dosage
PubMed: 27084120
DOI: 10.1016/j.radonc.2016.03.013 -
Physics in Medicine and Biology Sep 2022In online adaptive radiotherapy a new plan is generated every fraction based on the organ and clinical target volume (CTV) delineations of that fraction. This allows for...
In online adaptive radiotherapy a new plan is generated every fraction based on the organ and clinical target volume (CTV) delineations of that fraction. This allows for a planning target volume margin that does not need to be constant over the whole course of treatment, as is the case in conventional radiotherapy. This work aims to introduce an approach to update the margins each fraction based on the per-patient treatment history and explore the potential benefits of such adaptive margins.We introduce a novel methodology to implement adaptive margins, isotropic and anisotropic, during a treatment course based on the accumulated dose to the CTV. We then simulate treatment histories for treatments delivered in up to 20 fractions using various choices for the standard deviations of the systematic and random errors and homogeneous and inhomogeneous dose distributions. The treatment-averaged adaptive margin was compared to standard constant margins. The change in the minimum dose delivered to the CTV was compared on a patient and a population level. All simulations were performed within the van Herk approach and its known limitations.The population mean treatment-averaged margins are down to 70% and 55% of the corresponding necessary constant margins for the isotropic and anisotropic approach. The reduction increases with longer fractionation schemes and an inhomogeneous target dose distribution. Most of the benefit can be attributed to the elimination of the effective systematic error over the course of treatment. Interpatient differences in treatment-averaged margins were largest for the isotropic margins. For the 10% of patients that would receive a lower than prescribed dose to the CTV this minimum dose to the CTV is increased using the adaptive margin approaches.Adaptive margins can allow to reduce margins in most patients without compromising patients with greater than average target motion.
Topics: Dose Fractionation, Radiation; Humans; Margins of Excision; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Image-Guided
PubMed: 36096130
DOI: 10.1088/1361-6560/ac9175