OBJECTIVE: In the conventionally fractionated phase III FLAME prostate trial, focal boosts improved local control and biochemical disease-free survival (bDFS). We explored the toxicity and effectiveness of a moderately hypofractionated schedule with focal boosts.
METHODS: BIOPROP20 is a phase II single-arm non-randomised trial for intermediate- to very high-risk localised prostate cancer patients with bulky tumour volumes. Multi-parametric magnetic resonance imaging (MRI) and 18F-choline positron emission tomography-computed tomography (PET-CT) scans were used for staging and boost volume definition. Patients were treated with 60Gy in 20 fractions with a boost dose up to 68Gy. Five patients with positive lymph nodes on the PET-CT scan received radiotherapy to pelvic lymph nodes (45Gy to elective nodes, boosted up to 50Gy to involved nodes). Primary outcomes were acute (≤18 weeks) and late urinary and gastrointestinal toxicity, prospectively recorded up to 5 years with Common Terminology Criteria for Adverse Events v4 (CTCAE). Secondary outcomes were biochemical or clinical progression, metastasis-free survival (MFS), and overall survival (OS).
RESULTS: 61 patients completed radiotherapy with hormone therapy (range: 6-36 months). Cumulative acute and late gastrointestinal toxicity was low at 6.6% and 5.0%, respectively. Cumulative acute and late urinary toxicity was 49.2% and 30.1%, respectively; the prevalence reduced to 5.9% at 5 years. At 5 years: 6 patients had biochemical progression (bDFS: 88.5%; 95% CI: 80.2-97.6%), the MFS was 82.4% (95% CI: 73.0-92.9%), 5 patients died (OS: 91.2%; 95% CI: 84.1-98.9%), one with prostate cancer. The prostate, boost, nodal planning volumes, and the organs at risk (rectum, bowel, urethra, and bladder) met the optimal protocol dose constraints. There was a trend to increased urinary toxicity with increasing urethral (RR: 1.95, 95% CI: 0.73-5.22, p = 0.18), but not bladder dose.
CONCLUSIONS: Focal boosts with a 20 fraction hypofractionated prostate radiotherapy schedule are associated with an acceptable risk of gastrointestinal and urinary toxicity and achieve good cancer control.
RESULTS:
UNASSIGNED: NCT02125175.

UNASSIGNED: The major drivers of carbon dioxide (CO2eq) emissions of external beam radiation therapy (EBRT) are not well known and limit our ability to initiate mitigation strategies.
UNASSIGNED: We describe the carbon footprint of four typical centers. We explore direct EBRT associated factors such as the impact of fractionation and use of MRI-LINAC, as well as indirect factors (e.g. patient rides). Treatment strategy related CO2eq emissions are included in a health technology assessment analysis that takes into account CO2eq emissions.
UNASSIGNED: A typical EBRT treatment emits from 185 kgCO2eq to 2066 kgCO2eq. CO2eq emissions are mostly driven by (i) accelerator acquisition and maintenance (37.8 %), (ii) patients and workers rides (32.7 %), (iii) drugs and medical devices (7.3 %), (iv) direct energy consumption (6.1 %), and (v) building and bunker construction (5.6 %) with a substantial heterogeneity among centers. Hypofractionation has a strong impact to mitigate emissions. MRI-LINAC is associated with a substantial increase in CO2eq emissions per fraction and requires ultra hypofractionation in 5 fractions to achieve a similar carbon footprint compared to 20 fractions treatment schemes. The expected limited small increase in toxicities due to hypofractionation (when existing) are in the same range as avoided detrimental effects to future people\'s health thanks to CO2eq mitigation.
UNASSIGNED: Carbon footprint of EBRT is not neglectable and could be mitigated. When safely feasible, hypofractionation is one of the main factors to decrease this impact. Taking into account CO2eq emissions has a substantial impact on the health technology assessment of EBRT, favoring hypofractionated regimens.

BACKGROUND: Moderately hypofractionated, preoperative radiotherapy in patients with soft tissue sarcomas (HYPORT-STS; ClinicalTrials.gov identifier NCT03819985) investigated a radiobiologically equivalent, moderately hypofractionated course of preoperative radiotherapy (RT) 15 × 2.85 Gy in patients with soft tissue sarcoma (STS). Here, the authors report longer term follow-up to update local control and report late toxicities, as well as functional and patient-reported outcomes.
METHODS: HYPORT-STS was a single-center, open-label, single-arm, prospective phase 2 clinical trial that enrolled 120 eligible adult patients with localized STS of the extremities or superficial trunk between 2018 and 2021. Patients received a 3-week course of preoperative RT followed by surgery 4-8 weeks later. End points and follow-up were analyzed from the date of surgery.
RESULTS: The median follow-up was 43 months (interquartile range, 37-52 months), and the 4-year local recurrence-free survival rate was 93%. Overall RT-related late toxicities improved with time from local therapy (p < .001), and few patients had grade ≥2 toxicities (9%; n = 8 of 88) at 2 years. These included: 2% grade ≥2 skin toxicity, 2% fibrosis, 3% lymphedema, and 1% joint stiffness. Four patients (3%) had bone fractures. Both functional outcomes, as measured by the Musculoskeletal Tumor Society Rating Scale (p < .001), and quality of life, as measured by the Functional Assessment of Cancer Therapy-General (p < .001), improved with time from treatment, and both measures were better in follow-up at 2 years compared with baseline.
CONCLUSIONS: Long-term follow up suggests that moderately hypofractionated preoperative RT for patients with STS is safe and effective. Higher grade late toxicities affect a minority of patients. Late toxicities decrease over time, whereas functional outcomes and health-related quality of life seem to improve with more time from combined modality treatment.

OBJECTIVE: Prostate cancer is the most frequent cancer among men and radiotherapy hypofractionation regimens have become standard treatments for the localized stages, but the absence of increased risk of acute and late genitourinary or gastrointestinal toxicity of the dose escalation still must be demonstrated.
METHODS: The study population included all patients with localized prostatic adenocarcinoma treated at the institut Curie from February 2016 to March 2018 by external radiation delivered by a linear accelerator using an image-guided conformal intensity modulation technique at a total dose of 75Gy in 30 fractions of 2.5Gy in the planning target volume that included the prostate and the proximal seminal vesicles, and could be paired with a prophylactic lymph node radiotherapy at 46Gy in 23 fractions with simultaneous integrated boost.
RESULTS: A total of 166 patients were included. Among them, 68.6% were unfavourable intermediate or (very) high risk. The median age and follow-up were 71.4years and 3.96years. One hundred and forty-nine patients received prophylactic lymph node radiotherapy (89.8%). One hundred and thirty-one patients received hormonotherapy (78.9%). Genito-urinary toxicity events of grades 2 or above during radiotherapy, at 6months, 1year and 5years were respectively 36.7%, 8.8%, 3.1% and 4.7%. Two patients had late grade 4 toxicity at 5years (1.6%). Grade 2 gastrointestinal toxicity events during radiotherapy, 6months, 1year and 5years were respectively 15.1%, 1.9%, 14.6% and 9.3%. Of these, eight patients had grade 3 toxicity (6.2%). There was no grade 4 toxicity. Analyses did not reveal any predictive factor for toxicity. The 5-year overall, progression-free, and specific survival rates were respectively 82.4%, 85.7%, and 93.3%. Serum prostate specific antigen concentration and cardiovascular risk factors were found to be predictive factors of deterioration in overall survival (P=0.0028 for both).
CONCLUSIONS: External radiotherapy for localized prostatic cancer with our moderately hypofractionated dose escalation regimen is well tolerated. In the absence of increased late toxicity, the analysis of the modes of long-term relapses will be interesting to determine the benefit of this dose escalation on local and distant relapses.

OBJECTIVE: Radiotherapy (RT) is an integral component in the treatment of breast cancer. The aims of this study were to estimate the cost per 5-year Local Control (LC) and Overall Survival (OS) benefits of the first course of RT, based on breast cancer stage, and the potential cost savings with adoption of the FAST-Forward protocol.
METHODS: All RT activities for breast cancer RT July 2017-June 2020 and their associated costs were consolidated together. The average cost of treatment course was calculated (average cost per fraction X average no. of fractions). Cost per outcome was estimated based on published gains in 5-year LC and OS with optimal use of radiotherapy.
RESULTS: 481 patients with breast cancer were analysed. The average cost per fraction was $285 AUD (£148 GBP) for all stages. The average costs for 5-year LC and OS gain were $31,483 AUD (£16 392 GBP) and $235,435 AUD (£122 566 GBP) respectively for all stages. The estimated costs for 5-year LC outcomes were $29,675 AUD (£15 450 GBP), $34,675 AUD (£18 053 GBP) and $32,478 AUD (£16 910 GBP) for Stage I-III respectively. The estimated costs for 5-year OS were $455,909 AUD (£237 378 GBP), $532,727 AUD (£ 277 375 GBP) and $60,717 AUD (£31 614 GBP) for Stage I-III respectively. 266 patients had characteristics that made them eligible for the FAST-Forward protocol. A cost saving of $2592-3864 AUD (£1350-2012 GBP) per patient was estimated had these patients been treated with the protocol.
CONCLUSIONS: The cost of RT for LC outcome is similar across stages. The greatest value for OS outcome was seen in patients with Stage III breast cancer, due to the greater survival benefit with RT in these patients compared with Stage I-II breast cancer. Significant cost savings can be made by implementing the FAST-Forward protocol.

OBJECTIVE: To report a single-institutional experience with hypofractionated radiation therapy alone for human papillomavirus (HPV)-positive oropharyngeal cancer.
METHODS: A total of 101 consecutive patients were treated by radiation therapy alone using a regimen of 66 Gy in 30 fractions (60 patients) or 70 Gy in 33 fractions (41 patients) for newly diagnosed p16-positive squamous cell carcinoma of the oropharynx. Sixty-seven patients (67%) were never smokers.
RESULTS: The 3-year actuarial rates of overall survival, local-regional control, and progression-free survival were 94%, 93%, and 89%, respectively. Among never-smokers, the 3-year rates of overall survival and local-regional control were 98% and 100%, respectively. The grade 3+ acute toxicity rate was 21%, with the most commonly observed side effects related to mucositis.
CONCLUSIONS: Hypofractionated radiation alone resulted in excellent outcomes for patients with HPV-positive oropharyngeal cancer. A prospective clinical trial investigating this modality in the setting of de-escalation is currently underway.

OBJECTIVE: Hypofractionated radiotherapy (HFRT) is being used more frequently for many common cancer sites. Conventionally fractionated radiotherapy treatment regimens have remained the standard of care when radiotherapy is indicated for soft tissue sarcoma (STS). The aim of this study is to systematically review published data on the use of pre-operative hypofractionated radiotherapy as part of a curative treatment paradigm in patients with soft tissue sarcoma. Herein we summarise current evidence for the use of hypofractionated radiotherapy in the pre-operative treatment of STS.
METHODS: We conducted a database search for prospectively or retrospectively collected data on patients with a diagnosis of soft tissue sarcoma treated with HFRT. Studies evaluating soft tissues sarcoma of all histological subtypes affecting extremities or trunk were included in the search. Articles were screened by two independent reviewers for inclusion in this review. Patient, treatment, toxicity and outcome data was recorded and collated from selected studies.
RESULTS: 25 articles are included in this review. Nine prospective trials have been published since 2020. Dose fractionations range from 25-40Gy in 5 fractions or 28-42.75Gy in 8-15 fractions. Local control and overall survival outcomes are consistent with historical data for conventionally fractionated radiotherapy. Acute toxicity and wound complication rates are in keeping with acceptable results. Late toxicity data is limited and requires longer follow up. Rates of pathological complete response are promising across all studies.
CONCLUSIONS: There is a growing body of evidence supporting hypofractionation as safe and effective in the pre-operative treatment of STS. This review highlights potential areas that could be further investigated to optimise pre-operative treatment for soft tissue sarcoma.

UNASSIGNED: Despite the efficacy of endorectal balloon (ERB) in reducing rectal radiation dose, the effectiveness of upper rectal fixation remains to be evaluated. The purpose of this study was to evaluate the impact of ERB on upper rectal fixation in patients diagnosed with localized prostate cancer.
UNASSIGNED: Cine MRI was performed in 46 patients with localized prostate cancer to assess the stability of the anterior rectal wall with and without ERB by calculating the standard deviation of the normalized signal intensity at the level of the midgland or the seminal vesicle.
UNASSIGNED: The standard deviation of the normalized signal intensity for the anterior rectal wall decreased significantly with the use of ERB both at the level of the midgland (p < 0.05) and the seminal vesicle (p < 0.05). The standard deviation of the anterior rectal wall at the level of the seminal vesicle was significantly higher than at the level of the midgland without ERB (p < 0.05). But with ERB, the standard deviation of the normalized signal intensity at the level of the seminal vesicle became comparable to that at the level of the midgland (p = 0.392).
UNASSIGNED: The anterior rectal wall is stabilized by ERBs not only at the level of the midgland but also at the level of the seminal vesicle. ERBs can transform the rectum from a moving and deformable organ into a static and rigid organ.

Radionecrosis is a common complication in radiation oncology, while mechanisms and risk factors have yet to be fully explored. We therefore conducted a systematic review to understand the pathogenesis and identify factors that significantly affect the development.
We performed a systematic literature search based on the PRISMA guidelines using PubMed, Ovid, and Web of Science databases. The complete search strategy can be found as a preregistered protocol on PROSPERO (CRD42023361662).
We included 83 studies, most involving healthy animals (n = 72, 86.75 %). High doses of hemispherical irradiation of 30 Gy in rats and 50 Gy in mice led repeatedly to radionecrosis among different studies and set-ups. Higher dose and larger irradiated volume were associated with earlier onset. Fractionated schedules showed limited effectiveness in the prevention of radionecrosis. Distinct anatomical brain structures respond to irradiation in various ways. White matter appears to be more vulnerable than gray matter. Younger age, more evolved animal species, and genetic background were also significant factors, whereas sex was irrelevant. Only 13.25 % of the studies were performed on primary brain tumor bearing animals, no studies on brain metastases are currently available.
This systematic review identified various factors that significantly affect the induction of radionecrosis. The current state of research neglects the utilization of animal models of brain tumors, even though patients with brain malignancies constitute the largest group receiving brain irradiation. This latter aspect should be primarily addressed when developing an experimental radionecrosis model for translational implementation.

UNASSIGNED: Introducing moderately hypofractionated salvage radiotherapy (SRT) following prostatectomy obligates investigation of its effects on clinical target volume (CTV) coverage and organ-at-risk (OAR) doses. This study assessed interfractional volume and dose changes in OARs and CTV in moderately hypofractionated SRT and evaluated the 8-mm planning target volume (PTV) margin.
UNASSIGNED: Twenty patients from the PERYTON-trial were included; 10 received conventional SRT (35 × 2 Gy) and 10 hypofractionated SRT (20 × 3 Gy). OARs were delineated on 539 pre-treatment Cone Beam CT (CBCT) scans to compare interfractional OAR volume changes. CTVs for the hypofractionated group were delineated on 199 CBCTs. Dose distributions with 4 and 6 mm PTV margins were generated using voxel-wise minimum robustness evaluation of the original 8-mm PTV plan, and dose changes were assessed.
UNASSIGNED: Median volume changes for bladder and rectum were -26 % and -10 %, respectively. OAR volume changes were not significantly different between the two treatment schedules. The 8-mm PTV margin ensured optimal coverage for prostate bed and vesicle bed CTV (V95 = 100 % in >97 % fractions). However, bladder V60 <25 % was not achieved in 5 % of fractions, and rectum V60 <5 % was unmet in 33 % of fractions. A 6-mm PTV margin resulted in CTV V95 = 100 % in 92 % of fractions for prostate bed, and in 86 % for vesicle bed CTV.
UNASSIGNED: Moderately hypofractionated SRT yielded comparable OAR volume changes to conventionally fractionated SRT. Interfractional changes remained acceptable with a PTV margin of 6 mm for prostate bed and 8 mm for vesicle bed.