Daily Fractions Research Articles

Impact of Radiation Therapy Modalities on Loco-regional Control in Inflammatory Breast Cancer

In inflammatory breast cancer, radiation therapy intensification is considered a standard of care by some teams, although the level of evidence remains low. We sought to analyze the impact of radiation therapy modalities on the risk of loco-regional and distant relapse. This retrospective multicenter study included patients with localized inflammatory breast cancer treated between 2010 and 2017. Standard postmastectomy radiation therapy consisted of daily fractions to a total dose of 50 Gy equivalent without a boost or bolus, while intensified radiation therapy referred to the use of a boost or bolus. The cumulative incidence curves of locoregional and distant recurrence were displayed using the competing risk method. Of the 241 included patients, 165 were treated with standard and 76 with intensified radiation therapy. There was significantly more nodal involvement in the intensified group. With a median follow-up of 40 months postradiation therapy, there was no difference between standard versus intensified radiation therapy regarding the cumulative incidence of locoregional (P = .68) or distant recurrence (P = .29). At 5 years, the risks of locoregional and distant recurrence were 12.1% (95% CI, 7.5; 17.7) and 29.4% (95% CI, 21.8; 37.3) for patients treated with standard radiation therapy and 10.4% (95% CI, 4.4; 19.3) and 21.4% (95% CI, 12.6; 31.9) for those treated with intensified radiation therapy. In multivariate analyses, triple-negative subtype and absence of complete pathologic response were associated with a higher risk of loco-regional recurrence. Radiation therapy intensification had no significant impact on locoregional and distant recurrence. For patients with a non-complete pathologic response (n = 172, 71.7%), no significant differences were observed between the 2 groups for loco-regional (P = .80) and distant (P = .39) recurrence. Severe toxicity rates were similar in both groups. Contrary to other important series, this large retrospective multicentric study did not show a locoregional or distant control benefit of intensified radiation therapy. Pooled prospective studies and meta-analyses of intensified radiation therapy are warranted to endorse this approach.

Assessment of the safety and feasibility of neoadjuvant chemotherapy (2 cycles of FLOT chemotherapy + chemoradiotherapy) followed by surgery in the treatment of locally advanced gastric cancer

The aim of the study was to analyze of the safety and feasibility of neoadjuvant chemotherapy (2 cycles of FLOT chemotherapy + chemoradiotherapy) followed by surgery in the treatment of locally advanced gastric cancer. Material and Methods. The phase II clinical trial included 47 patients with histologically verified locally advanced gastric cancer (cT3/T4a-b: 26/21 and cN0/N1–3: 20/27) treated at the A.F. Tsyba MRRC from 2018 to 2021. Lesion location was: upper third in 19 patients (esophageal invasion in 9 patients), middle third in 13 patients, lower third in 14 patients, and entire stomach in 1 patient. The tumor grade was G3 in 23 patients, G2 in 13 patients and G1 in 7 patients. Signet ring cell carcinoma was revealed in 4 patients. The patients received 2 cycles of induction chemotherapy with FLOT regimen (85 mg/m2 oxaliplatin + 200 mg/m2 calcium folinate + 50 mg/m2 docetaxel on day 1 + 2600 mg/m2 fluorouracil as 24-hour infusion from day 1; every 2 weeks) followed by 3d-conformal external beam radiotherapy (46 Gy in daily fractions of 2 Gy) combined with chemotherapy with capecitabine and oxaliplatin). The patients then underwent follow-up examination to exclude disease progression and to plan surgery. Postoperative complications were analyzed using the Clavien-dindo classification. Results. Induction chemotherapy followed by concurrent chemoradiotherapy was well tolerated. Forty-five (95.7 %) patients underwent surgery, 97.7 % of them underwent radical surgery. Postoperative complications were observed in 11 (23.4 %) patients. Grade III and more severe complications were observed in 3 (6.4 %) patients. It should be noted that postoperative mortality rate was low, amounting to 2.2 % (1 patient). Conclusion. Induction FLOT polychemotherapy followed by concurrent chemoradiotherapy was shown to be safe, feasible, and tolerable. Moreover, this treatment regimen did not reduce the frequency of R0 surgeries and did not increase incidence and severity of postoperative complications.

Improved estimates of smoke exposure during Australia fire seasons: importance of quantifying plume injection heights

Abstract. Wildfires can have a significant impact on air quality in Australia during severe burning seasons, but incomplete knowledge of the injection heights of smoke plumes poses a challenge for quantifying smoke exposure. In this study, we use two approaches to quantify the fractions of fire emissions injected above the planetary boundary layer (PBL), and we further investigate the impact of plume injection fractions on daily mean surface concentrations of fine particulate matter (PM2.5) from wildfire smoke in key cities over northern and southeastern Australia from 2009 to 2020. For the first method, we rely on climatological, monthly mean vertical profiles of smoke emissions from the Integrated Monitoring and Modelling System for wildland fires (IS4FIRES) together with assimilated PBL heights from NASA Modern-Era Retrospective Analysis for Research and Application (MERRA) version 2. For the second method, we develop a novel approach based on the Multi-angle Imaging SpectroRadiometer (MISR) observations and a random forest, machine learning model that allows us to directly predict the daily plume injection fractions above the PBL in each grid cell. We apply the resulting plume injection fractions quantified by the two methods to smoke PM2.5 concentrations simulated by the Stochastic Time-Inverted Lagrangian Transport (STILT) model in target cities. We find that characterization of the plume injection heights greatly affects estimates of surface daily smoke PM2.5, especially during severe wildfire seasons, when intense heat from fires can loft smoke high in the troposphere. However, using climatological injection profiles cannot capture well the spatiotemporal variability in plume injection fractions, resulting in a 63 % underestimation of daily fire emission fluxes injected above the PBL in comparison with those fluxes derived from MISR injection fractions. Our random forest model successfully reproduces the daily injected fire emission fluxes against MISR observations (R2=0.88, normalized mean bias = 10 %) and predicts that 27 % and 45 % of total fire emissions rise above the PBL in northern and southeastern Australia, respectively, from 2009 to 2020. Using the plume behavior predicted by the random forest method also leads to better model agreement with observed surface PM2.5 in several key cities near the wildfire source regions, with smoke PM2.5 accounting for 5 %–52 % of total PM2.5 during fire seasons from 2009 to 2020.

Efficacy and safety of anlotinib combined with the STUPP regimen in patients with newly diagnosed glioblastoma: a multicenter, single-arm, phase II trial.

Glioblastomas are highly vascularized malignant tumors. We determined the efficacy and safety of the anti-angiogenic multi-kinase inhibitor, anlotinib, for a newly diagnosed glioblastoma. This multicenter, single-arm trial (NCT04119674) enrolled 33 treatment-naïve patients with histologically proven glioblastomas between March 2019 and November 2020. Patients underwent treatment with the standard STUPP regimen [fractionated focal irradiation in daily fractions of 1.8-2 Gy given 5 d/w × 6 w (total = 54-60 Gy)] or radiotherapy plus continuous daily temozolomide (TMZ) (75 mg/m2 of body surface area/d, 7 d/w from the first to the last day of radiotherapy), followed by 6 cycles of adjuvant TMZ (150-200 mg/m2 × 5 d during each 28-d cycle) plus anlotinib (8 mg/d on d 1-14 of each 3-w cycle for 2 cycles during concomitant chemoradiotherapy, 8 maximal cycles as adjuvant therapy, followed by maintenance at 8 mg/d. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS) and adverse events (AEs). Thirty-three patients received the planned treatment. The median PFS was 10.9 months (95% CI, 9.9-18.7 months) and the 12-month PFS rate was 48.5%. The median OS was 17.4 months (95% CI, 14.5-21.1 months) and the 12-month OS rate was 81.8%. The most common AEs included hypertriglyceridemia [58% (n = 19)], hypoalbuminemia [46% (n = 15)], and hypercholesterolemia [46% (n = 15)] during concurrent chemoradiotherapy and leukopenia [73% (n = 24)], hypertriglyceridemia [67% (n = 22)], and neutropenia [52% (n = 17)] during adjuvant therapy. Five patients discontinued treatment due to AEs. HEG1 (HR, 5.6; 95% CI, 1.3-23.7; P = 0.021) and RP1L1 alterations (HR, 11.1; 95% CI, 2.2-57.2; P = 0.004) were associated with a significantly shorter PFS. Anlotinib plus the STUPP regimen has promising anti-tumor activity against glioblastoma and manageable toxicity. HEG1 and RP1L1 alterations might be novel predictive biomarkers of the response to anlotinib.

Brain Re-Irradiation Or Chemotherapy: a phase II randomised trial of re-irradiation and chemotherapy in patients with recurrent glioblastoma (BRIOChe) – protocol for a multi-centre open-label randomised trial

IntroductionGlioblastoma (GBM) is the most common adult primary malignant brain tumour. The condition is incurable and, despite aggressive treatment at first presentation, almost all tumours recur after a median of...

Dose-escalated SBRT for borderline and locally advanced pancreatic cancer. Feasibility, safety and preliminary clinical results of a multicenter study

BackgroundPancreatic Stereotactic Body Radiotherapy (SBRT) allows for the administration of a higher biologically effective doses (BED), that would be essential to achieve durable tumor control. Escalating treatment doses need a very accurate tumor positioning and motion control during radiotherapy.The aim of this study to assess the feasibility and safety of a Simultaneous Integrated Boost (SIB) dose-escalated protocol at 45 Gy, 50 Gy and 55 Gy in 5 consecutive daily fractions, in Border Line Resectable Pancreatic Cancer (BRCP) /Locally Advanced Pancreatic Cancer (LAPC) by means of a standard LINAC platform. MethodsPatients diagnosed of BRPC/LAPC, candidates for neoadjuvant chemotherapy and SBRT, in four university hospitals of the province of Las Palmas (Canary Islands, Spain) were included in this prospective study. Radiotherapy was administered using standard technology (LINACS) with advanced positioning (Lipiodol® and metallic stent used as fiducial markers) and tumor motion control (4D, DBH, Calypso®). There were 3 planned dose-escalated SIB groups, 45 Gy/5f (9 patients) 50 Gy/5f (9 + 9 patients) and 55 Gy/5f (9 patients). The defined primary end points of the study were the safety and feasibility of the proposed treatment protocol. Secondary endpoints included radiological tumor response after SBRT, local control and survival. ResultsFrom June 2017 to December 2022, sixty-two patients were initially assessed for eligibility in the study in the four participating centers, and 49 were candidates for chemotherapy (CHT). Forty-one were referred to radiotherapy after CHT and 33 finally were treated by escalated-dose SIB, 45 Gy (9 patients) 50 Gy (16 patients), 55 Gy(8 patients). All patients completed the scheduled treatment and no acute or late severe (≥grade3) gastrointestinal toxicity was observed.Local response was analyzed by CT/MRI two months after the end of SBRT. Ten patients (31,25 %) achieved objective response (2/9:45 Gy, 5/15:50 Gy, 3/8:55 Gy). Follow-up was closed as July 2023. Freedom from local progression at 1-2y were 89,3% (95 %CI:83,4–95,2%) and 66 % (95 %CI:54,6–77,4%) respectively. The 1-2y survival rates were 95,7% (95 %CI:91,4–100 % and 48,6% (95 %CI:37,7–59,5%) respectively. ConclusionThese promising results should be confirmed by further studies with larger sample size and extended follow-up period.

Automatic mapping of 500 m daily open water body fraction in the American continent using GOES-16 ABI imagery

Timely and large-area monitoring of terrestrial water bodies using remote sensing data is essential to protect water resource security for humans and ecosystems. Although efforts have been made to monitor inter-monthly water bodies at the regional, continental and global scales, surface open water bodies may experience rapid changes within a short duration. At the same time, the data gaps caused by the long revisit frequencies of satellite sensor imaging systems and the extremely cloudy and rainy weather in certain areas mean that a suitable operational method for recording such rapid changes over large areas does not yet exist. The recently launched operational geostationary satellite sensor GOES-16 ABI can provide multi-scale optical images every 10 min in the Americas, and it has great potential to provide a new solution for timely open surface water monitoring. In this research, a framework based on a multi-scale non-linear mixture model (NLMM) was proposed for the automatic estimation of 500 m daily open water body fraction maps across the full extent of the American continent from GOES-16 ABI imagery. Specifically, an exterior spectral library was created firstly from many pairs of training GOES-16 ABI images and 500 m water body fraction maps derived from Landsat images, and an inherited interior pure spectral library was then derived from a pair of the testing GOES-16 ABI image and the corresponding pure water and non-water (i.e., vegetation and soil/rock substrate) fractions extracted from the monthly water recurrence dataset. Furthermore, a synthetic interior mixed spectral library was built finally based on the linear and non-linear mixtures of randomly selected pure endmembers of water and non-water (i.e., vegetation and soil/rock substrate) in the testing image. All the exterior and interior pure and synthetic mixed spectral libraries were employed jointly in the NLMM machine learning method for estimating daily water body fractions with GOES-16 ABI images. Experiments show that the integration of all three different spectral libraries produced 500 m open water body fraction maps with the greatest accuracies. Compared to traditional linear spectral unmixing and a water index thresholding method, the proposed method produced more accurate results both quantitatively and visually. Moreover, the proposed method can produce time-series daily 500 m open water body fraction maps with minimal cloud coverage for the full extent of the Americas by combining dense GOES-16 ABI images at half-hour intervals, opening up great possibilities for near real-time rapid open water body changes monitoring, such as flooding and drought, over large areas, even with a high frequency of cloud cover.

Effect of Radiotherapy on Activating the Pyroptotic Cell Death Pathway in Breast Cancer Patients: The Role of Serum GSDMD-CT, NLRP3 and IL-18.

Breast cancer (BC) is the most common form of cancer among women and the second leading cause of cancer-related death worldwide. Several malignancies can be successfully treated with radiation (RT), although radioresistance is still a major contributor to radiotherapy failure. Ionizing radiation (IR) induces pyroptosis in cancer cells. Pyroptosis is a designed method of death connected to routine immunity and directly related to the body ROS content. Objective for the study: The aim of this work was to investigate the role of serum GSDMD-CT, nucleotide-binding domain and leucine-rich-repeat-containing family pyrin 3 (NLRP3) and IL-18 as predictors of pyroptotic cell death mechanism induced by radiotherapy in breast cancer patients. The 70 female participants in this study were divided into two groups: Group (I): 40 breast cancer patients treated with radiotherapy. Group (II): a control group of 30 healthy volunteers with similar ages and sex. Patients with breast cancer received radiation, with a dose of 44 Gray administered over the course of 16 days in five daily fractions of 2.75 Gray each. Two blood samples were taken from breast cancer patients: one before radiotherapy and the other after radiotherapy. While one blood sample was taken from healthy controls. The levels of the circulating pyroptosis biomarkers IL-18, NLRP3, and GSDMD-CT were measured using the ELISA method. Our results showed that, there was a significant increase in serum pyroptosis markers GSDMD-CT, NLRP3 and IL-18 in BC Patients after RT when compared to before radiotherapy. Radiotherapy induced pyroptosis in breast cancer patients as a new cell death mechanism. GSDMD-CT, NLRP3 and IL-18 are biomarkers of pyroptosis that significantly increased post irradiation highlighting enhanced ROS and pyroptosis induction.

Canine primary liver tumors treated with stereotactic body radiation therapy: A case series.

Stereotactic body radiation therapy (SBRT) is an increasingly used alternative treatment option for nonresectable hepatocellular carcinoma (HCC) in people. Comparatively, the publication of SBRT of dogs with HCC is limited. The objective of this retrospective, descriptive case series was to evaluate the clinical outcomes and toxicity data of SBRT in dogs with HCC and imaging-documented primary liver tumors using volumetric-modulated arc therapy delivery at two private institutions. Medical records of 14 dogs treated between 2018 and 2023 were reviewed. All dogs had macroscopic tumors, and 9 of 14 dogs had HCC diagnoses confirmed on cytology or histopathology. The median longest tumor diameter was 5.5cm. The median percentage of planning target volume relative to liver volume was 27.1%. Most dogs were treated with three daily fractions of 7-7.5Gy. All dogs completed their radiotherapy protocols. Three of nine HCC dogs experienced partial responses and clinical improvement. Five of nine HCC dogs had stable disease. Overall median survival time was 164 days for nine HCC dogs (range: 93-706 days). One late grade 5 liver and two late grade 3 kidney side effects were reported. One dog received repeated SBRT to the same HCC treatment field, and one dog had two courses of SBRT to bifocal HCC treatment fields, both with no more than grade 2 acute and chronic toxicities.

Organ preservation with durvalumab-based immunotherapy in combination with chemoradiation as definitive therapy for early stage, cT1, and cT2N0 esophageal adenocarcinoma with indication for radical surgery: A prospective, multicenter study of the FLOT-AIO Gastric Cancer Group (IKF-t057/PRESTO trial).

TPS431 Background: The outcome of patients (pts) with adenocarcinomas of stomach and esophagogastric junction (GEJ) remains unsatisfactory (5-year survival rates of 24-84%), whereby surgical resection is considered as cornerstone of the curative treatment for pts with early stage esophageal adenocarcinoma (EGA), however, it is associated with mortality, morbidity and an impact on the patient’s quality of life. Recent investigations showed that in locally advanced stage EGA surgery with neoadjuvant chemoradiotherapy (CROSS trial) is beneficial over surgery alone. Further benefit was achieved for locally advanced EGA by perioperative treatment with FLOT acc. to FLOT4- trial data. Immuno-oncology (IO) therapy by using checkpoint inhibitors is approved in the palliative and adjuvant EGA situation. In this trial we aim for the organ preservation treatment of EGA pts with a combination of the anti PD-L1 antibody durvalumab- FLOT - and chemoradio-therapy. Methods: This is a multicenter, single arm, open-label, phase II trial including a total of 32 pts with T1-T2N0 EGA (including GEJ) with indication for radical surgery. Enrolled pts will receive immunotherapy with durvalumab (1500 mg Q4W) in parallel to 2 cycles FLOT (50 mg/m2 docetaxel, 85 mg/m2 oxaliplatin, 200 mg/m2 calcium folinate and 2600 mg/m2 5FU, Q2W) induction followed by 3 cycles of mFOLFOX (85 mg/m2 oxaliplatin, 200 mg/m2 calcium folinate, 400 mg/m2 5FU bolus and 1600 mg/m2 5FU over 48h, Q2W) plus concomitant radiation (25 daily fractions with 2.0 Gy = Σ50Gy). 8 weeks after last treatment, pts will undergo tumor assessment by esophagogastroduodenoscopy with biopsies, endoscopic ultrasonography, and CT- or MRI-scans. Surgical resection would be offered only to pts in whom a locoregional persistence is confirmed. Pts with complete remission will enter the maintenance phase and will receive durvalumab monotherapy (1500 mg, Q4W) for a maximum of 12 cycles accompanied by regular tumor re-evaluation. Primary endpoint is the rate of cCR/pCR at time of re-evaluation. Secondary endpoints include rate of cCR/pCR at 1, 2 and 3 years, rate of salvage surgery, 90 day and 1 year mortality after start of treatment, safety and quality of life. In this exploratory trial a cCR/pCR rate of ≥75% would indicate that the study treatment should be further investigated, whereas a rate < 55% indicates no further investigation. First patient was enrolled on 2023-08-28. Currently one patient is recruited. Clinical trial information: NCT05713838 .

Dual Nucleosomal Double-Strand Breaks Are the Key Effectors of Curative Radiation Therapy

Most ionizing radiation produces δ-rays of ≈1 keV that can impart MGy doses to 100 nm3 volumes of DNA. These events can produce severe dual double-strand breaks (DDSBs) on nucleosomes, particularly in dense heterochromatic DNA. This is the most common multiply damaged site, and their probabilities determine the biological effectiveness of different types of radiation. We discuss their frequency, effect on cell survival, DNA repair, and imaging by gold nanoparticle tracers and electron microscopy. This new and valuable nanometer resolution information can be used for determining the optimal tumor cure by maximizing therapeutic effects on tumors and minimizing therapeutic effects on normal tissues. The production of DDSBs makes it important to deliver a rather high dose and LET to the tumor (>2.5 Gy/Fr) and at the same time reach approximately 1.8–2.3 Gy of the lowest possible LET per fraction in TP53 intact normal tissues at risk. Therefore, their intrinsic low-dose hyper-sensitivity (LDHS)-related optimal daily fractionation window is utilized. Before full p53 activation of NHEJ and HR repair at ≈½ Gy, the low-dose apoptosis (LDA) and LDHS minimize normal tissue mutation probabilities. Ion therapy should thus ideally produce the lowest possible LET in normal tissues to avoid elevated DDSBs. Helium to boron ions can achieve this with higher-LET Bragg peaks, producing increased tumor DDSB densities. Interestingly, the highest probability of complication-free cure with boron or heavier ions requires a low LET round-up for the last 10–15 GyE, thereby steepening the dose response and further minimizing normal tissue damage. In conclusion, the new high-resolution DSB and DDSB diagnostic methods, and the new more accurate DNA-repair-based radiation biology, have been combined to increase our understanding of what is clinically important in curative radiation therapy. In fact, we must understand that we already passed the region of optimal LET and need to go back one step rather than forward, with oxygen being contemplated. As seen by the high overkill and severely high LET in the distal tumor and the increased LET to normal tissues (reminding of neutrons or neon ions), it is therefore preferable to use lithium–boron ions or combine carbon with an optimal 10–15 GyE photon, electron, or perhaps even a proton round-up, thus allowing optimized, fractionated, curative, almost complication-free treatments with photons, electrons, and light ions, introducing a real paradigm shift in curative radiation therapy with a potential 5 GyE tumor boost, 25% increase in complication-free cure and apoptotic–senescent Bragg Peak molecular light ion radiation therapy.

Is Ultrahypofractionated Whole Pelvis Radiation Therapy (WPRT) as Well Tolerated as Conventionally Fractionated WPRT in Patients With Prostate Cancer? Early Results From the HOPE Trial

ObjectiveTo evaluate acute toxicity and quality of life (QOL) impact of ultra-hypofractionated whole pelvis radiotherapy (WPRT) compared to conventional WPRT fractionation post high-dose rate (HDR) prostate brachytherapy (BT). MethodsBLINDED FOR REVIEW is a phase 2, multi-institutional randomized controlled trial involving men with prostate-confined disease and NCCN unfavorable intermediate, high, or very-high-risk prostate cancer. Patients were randomly assigned to receive conventionally fractionated WPRT (standard arm) or ultra-hypofractionated WPRT (experimental arm) in a 1:1 ratio. All patients underwent radiotherapy with 15 Gy HDR-BT boost in a single fraction followed by WPRT delivered with conventional fractionation (45 Gy in 25 daily fractions or 46 Gy in 23 fractions) or ultra-hypofractionation (25 Gy in 5 fractions delivered on alternate days). Acute toxicities, measured during radiotherapy and at 6 weeks post-treatment, were assessed using the clinician-reported Common Terminology Criteria for Adverse Events (CTCAE) version 5.0, and QOL was measured using the Expanded Prostate Cancer Index Composite (EPIC-50) and International Prostate Symptom Score (IPSS). ResultsA total of 80 patients were enrolled and treated across three Canadian institutions. A total of 39 and 41 patients received external radiotherapy with conventionally fractionated and ultra-hypofractionated WPRT, respectively. All patients received androgen deprivation therapy, except for 2 patients treated in the ultra-hypofractionated arm. Baseline clinical characteristics were similar between the two arms, with 51 (63.8%) patients having high or very high-risk prostate cancer disease. Treatment was well tolerated with no significant differences in the rate of acute adverse events between arms. No grade 4 adverse events or treatment-related deaths were reported. Ultra-hypofractionated WPRT had a less detrimental impact in the EPIC-50 bowel total, function and bother domain scores when compared to conventional WPRT in the acute setting. On the contrary, more patients treated with ultra-hypofractionated WPRT reached the minimum clinical important difference on EPIC-50 urinary domains. No significant QOL differences between arms were noted in the sexual and hormonal domains. ConclusionUltra-hypofractionated WPRT following HDR-BT is a well-tolerated treatment strategy in the acute setting and leads to less detrimental impact on bowel QOL domains when compared to conventional WPRT.

Effect of different CTV shrinkage and skin flash margins on skin dose for left chest wall IMRT: A dosimetric study

In postmastectomy radiation therapy (PMRT), the adequate skin surface dose remains a problem. In this study, the effect of different CTV shrinkage and Skin flash margins on skin dose was investigated, and the accuracy of skin surface dose calculated by TPS for PMRT using thermoluminescent dosimeters (TLDs) was evaluated. Eighty-eight measurement points were determined on the Alderson Rando phantom. To determine the effects of shrinkage margin on skin dose, separate CTVs were generated for 2 mm, 3 mm and 5 mm shrinkage. The prescribed dose was 50 Gy to CTV with a daily fraction dose of 2 Gy. A total of 12 plans were created using four different skin flash thicknesses for each CTV shrinkage margin. After applying 0 mm, 10 mm, 15 mm and 20 mm skin flash thicknesses for each area of the 7F-IMRT treatment plan, the plans were recalculated, and the SF-0, SF-10, SF-15 and SF-20 plans were created, respectively. The increase in skin flash thickness in IMRT plans resulted in a significant increase in skin dose. There was a significant difference between TPS and TLD doses in all chest wall areas for SF-0, SF-10, and SF-15 (p < 0.05). However, there was no significant difference in all areas of the chest wall for SF-20 (p > 0.05). The shrinkage margin thickness of the CTV was found to be inversely proportional to the skin dose for all treatment plans. In tumors near the surface, bolus or skin flash techniques can get the skin adequately dosed. However, the skin flash technique has shown superiority in the application. In PMRT, it is recommended to keep the shrinkage margin as small as possible and use the skin flash thickness of 20 mm for the skin to receive a sufficient dose.

Ubiquitous Sea Surface Temperature Anomalies Increase Spatial Heterogeneity of Trade Wind Cloudiness on Daily Time Scale

Abstract The impact of weak submeso- to mesoscale SST anomalies on daily averaged trade cumulus cloudiness is investigated using satellite observations that have been validated against shipboard measurements from the Atlantic Tradewind Ocean–Atmosphere Mesoscale Interaction Campaign (ATOMIC). Daily spatial SST anomalies are identified from GOES–POES Blended SST analysis within a 10° × 10° region during January and February 2020. Daily averaged cloud fraction and 10-m neutral wind from satellite observations and reanalysis are composited over the identified SST features, using a common coordinate system based on the near-surface background wind directions. Composites of satellite cloud fraction show a statistically significant increase of cloudiness over the SST warm core with a reduction of cloudiness away from it. These responses are largely the same but with opposite signs over SST cold anomalies, suggesting that spatial heterogeneity in SST can locally imprint on daily cloud fraction. Composites of daily 10-m wind speed and wind convergence anomalies from both satellite and reanalysis show that surface wind speed is increased over SST warm anomalies, implying enhanced turbulence over warmer SSTs. Correspondingly, the surface convergence anomalies in these composites are located around the maximum downwind SST gradient, offset downwind from the cloudiness anomalies. These results indicate that the response of daily cloudiness to these SST anomalies is more likely generated by spatial variability of surface-driven turbulence and surface fluxes rather than that of surface or boundary layer convergence.

Daily fraction dose-adjusted radiotherapy policy to avoid prolonging the overall treatment time for early glottic squamous cell carcinoma: a single-institutional retrospective study.

The objective of this study was to determine the outcomes of radical radiotherapy for early glottic squamous cell carcinoma (EGSCC) with the policy of increasing the fraction size during radiotherapy when the overall treatment time (OTT) was expected to be prolonged. Patients diagnosed with clinical T1-2N0M0 EGSCC, who were treated with radical radiotherapy between 2008 and 2019 at Hokkaido University Hospital, were included. Patients received 66Gy in 33 fractions for T1 disease and 70Gy in 35 fractions for T2 disease as our standard regimen (usual group [UG]). If the OTT was expected to extend for >1 week, the dose fraction size was increased from 2.0to 2.5Gy from the beginning or during radiotherapy (adjusted group [AG]). At this time, we performed a statistical analysis between UG and AG. In total, 116 patients were identified, and the treatment schedules of 29 patients were adjusted. The median follow-up was 60.9months. In the T1 group, the cumulative 5-year local failure rate was 12.0% in the AG and 15.4% in the UG, and in the T2 group, the rate was 40.7% in the AG and 25.3% in the UG. There were no significant differences between the AG and UG. Similarly, no significant differences were observed for overall survival and progression-free survival rates. Our single-institutional retrospective analysis of EGSCC patients suggested that a method of adjusting the radiotherapy schedule to increase fraction size from the beginning or during the course may be effective in maintaining treatment outcomes.

Phase 2 Clinical Trial of Simultaneous Boost Intensity Modulated Radiation Therapy With 3 Dose Gradients in Patients With Stage I-II Nasal Type Natural Killer/T-Cell Lymphoma: Long-Term Outcomes of Survival and Quality of Life

The aim of this study was to investigate the treatment results and long-term quality of life in patients with early-stage extranodal natural killer/T-cell lymphoma who were prospectively treated with simultaneous boost intensity modulated radiation therapy (SIB-IMRT) with 3 dose gradients. Sixty patients with stage I-II nasal cavity natural killer/T-cell lymphoma (NKTCL) and Waldeyer's ring NKTCL were enrolled in a single-arm, prospective, phase 2 clinical trial from August 2011 to April 2015. All patients were treated with definitive radiation therapy combined with short-course induction chemotherapy. A newly designed SIB-IMRT scheme was uniformly adopted, with 54.6 Gy for the gross tumor volume (GTV) of the primary tumor and GTV of the positive lymph nodes, 50.7 Gy for the high-risk clinical target volume (CTV), and 45.5 Gy for the low-risk CTV, all delivered in 26 daily fractions. Before SIB-IMRT, L-asparaginase-based induction chemotherapy was used in 95.0% (57/60) of patients. With a median follow-up time of 95.8 months, the 5-year locoregional recurrence-free survival, progression-free survival, and overall survival rates were 83.3%, 81.7%, and 88.3%, respectively. Dosimetric analysis in the first 21 patients showed satisfying conformality for planning target volume of GTV, high-risk CTV, and low-risk CTV, while the organs at risk were well protected. The results of long-term quality-of-life investigations in patients without progression were favorable, and nasal discomfort was the most common symptom. No grade 3 or 4 acute or late toxicities were observed. The scheme of target volume delineation and dose setting that we designed has favorable clinical effects with mild side effects in treating patients with stage I-II nasal cavity NKTCL and Waldeyer's ring NKTCL.

Conventionally fractionated radiation therapy is associated with long-term survival in dogs with infiltrative lipomas.

To describe radiotherapy outcomes for canine infiltrative lipomas and provide detailed radiotherapy planning data. 24 dogs from 2000 to 2020. In this retrospective study, dogs received 1 to 3 surgeries prior to conventionally fractionated radiotherapy for gross (18) or microscopic (8) infiltrative lipomas. Dogs received 45 to 51 Gray (Gy) in 15 to 20 daily fractions, with 71% of dogs receiving 48 Gy in daily 3-Gy fractions. Masses were regionally located as follows: limbs (7), trunk (13), head/neck (4). At analysis, 16/24 dogs were deceased, 5/24 were alive (median follow-up for alive dogs: 1,216 days [range, 741 to 1,870 days]), and 3/24 were lost to follow-up. One living dog had progressive disease 923 days after completing conventionally fractionated radiotherapy and received another surgery. The estimated median overall survival (OS) after completing radiotherapy was 4.8 years (1,760 days; 95% CI, 1,215 to 2,777 days; range, 23 to 3,499 days) for any cause of death, and no patients were reported to have been euthanized or died from their tumor. No statistically significant difference was found for dogs based on gross versus microscopic disease (gross OS, 4.8 years vs microscopic OS, 3.6 years; P = .45). Furthermore, the number of surgeries before radiotherapy did not impact survival (P = .96). The survival difference between females (median OS, 7.6 years; 95% CI, 963 days to not reached) versus males (median OS, 4.6 years; 95% CI, 335 to 2,245 days; P = .05) was statistically significant, although 4/5 living dogs were female. This study demonstrates lengthy survivals with radiotherapy, even with gross disease, for dogs with infiltrative lipomas.

Accelerated Partial Breast Irradiation Using 5 Daily Fractions: A Prospective, Phase 2, Multicenter Trial of Cosmetic Outcomes and Toxicity—ACCEL Final Results

PurposeTo investigate cosmetic degradation and toxicity for an APBI prescription delivered in five fractions over one week compared to WBI. MethodsThe trial is a multicentre, single-arm, phase II, prospective cohort study. Eligible women 50 years of age or older with ER-positive, HER2-negative, invasive ductal carcinoma or ductal carcinoma in situ after breast conserving surgery received 27 Gy in five daily fractions of APBI. The primary endpoint was non-inferiority of two-year cosmesis using the RAPID trial's WBI arm as the control arm. A global, consensus cosmetic score using the EORTC rating scale of excellent, good, fair, or poor for each patient at baseline and two-years was generated by a panel of five radiation oncologists using photographs of treated and untreated breasts. ResultsFrom 2016 to 2019, 298 eligible women were enrolled. By the two-year follow-up, 76 patients were lost or withdrew, and three had died, resulting in 219 patients available for complete, two-year photographic cosmetic evaluation. The median (interquartile range) follow-up for all participants was 4·7 years (3·8 – 5·5 years). No patient had a fair or poor cosmetic score at the two-year evaluation. Cosmesis was better or unchanged for 97% of patients, worse for 3% (excellent to good), and no cosmetic failures. The confidence intervals are 0·88 (0·86-0·90) and 1·00 (0·99-1·00) for the RAPID and ACCEL trials, respectively. ConclusionCosmetic degradation of five daily treatments of the ACCEL trial's APBI intervention is noninferior to the WBI arm of the RAPID trial.

Pembrolizumab with Chemoradiation as Treatment for Muscle-invasive Bladder Cancer: Analysis of Safety and Efficacy of the PCR-MIB Phase 2 Clinical Trial (ANZUP 1502)

BackgroundRadiation may improve the efficacy of immune checkpoint inhibition. This study investigates the combination of pembrolizumab and chemoradiation (CRT) for muscle-invasive bladder cancer (MIBC). ObjectiveTo assess the feasibility and safety of pembrolizumab combined with CRT for MIBC. Design, setting, and participantsA single-arm phase 2 trial was performed with 28 participants having cT2-T4aN0M0 MIBC (Eastern Cooperative Oncology Group performance status 0–1; estimated glomerular filtration rate ≥40 ml/min; no contraindications to pembrolizumab) suitable for CRT. InterventionWhole bladder radiation therapy (RT; 64 Gy in 32 daily fractions, over 6.5 wk, combined with cisplatin (35 mg/m2 intravenously [IV] weekly, six doses) and pembrolizumab (200 mg IV q3 weeks, seven doses), both starting with RT. Surveillance cystoscopy/biopsy and computerised tomography scans performed 12 and 24 wk after CRT. Outcome measurements and statistical analysisThe primary endpoint was feasibility, determined by a prespecified satisfactory low rate of grade 3 or worse nonurinary toxicity or completion of planned CRT according to defined parameters. Secondary endpoints were complete cystoscopic response, locoregional progression-free survival (LRPFS), distant metastasis-free survival (DMFS), and overall survival (OS). Results and limitationsTwenty-eight patients were enrolled with a 31-mo median follow-up. Six had Grade >3 nonurinary adverse events during/within 12 wk after treatment; three had more than one cisplatin dose reduction. The 24-wk post-CRT complete response (CR) rate was 88%. Eight patients developed metastatic disease, and three had nonmetastatic progression. The DMFS at 2 yr is 78% (95% confidence interval [CI] 54–90%), with LRPFS at 2 yr of 87% (95% CI 64–96%) and median OS of 39 mo (95% CI 17.1–not evaluable). Limitations are the single-arm design and sample size. ConclusionsCombining pembrolizumab with CRT for MIBC was feasible, with manageable toxicity and promising CR rates. Patient summaryImmunotherapy treats nonmetastatic/metastatic bladder cancer effectively. We combined pembrolizumab with chemotherapy and radiation to assess its safety and impact on treatment delivery. The combination was feasible with encouraging early activity. Further larger trials are warranted.

Accelerated Partial Breast Irradiation for HER2-Positive Early-Stage Breast Cancer

HER2-positive (HER2+) breast cancer historically exhibited the most adverse local outcomes and, consequently, has had limited representation among trials of partial breast irradiation (PBI). We hypothesized that with contemporary HER2-targeted agents, patients may now exhibit excellent disease control outcomes after adjuvant PBI. Using a prospectively maintained institutional database, we identified patients with HER2+ breast cancer treated with breast conserving surgery (BCS) and PBI from 2000 to 2022. Salient clinicopathologic and treatment parameters were collected. All patients received external beam PBI to 40 Gy in 10 daily fractions. Cumulative incidence functions were calculated to estimate the incidence of local recurrence (LR) with the competing risk of death. We identified 1248 patients who underwent PBI at our institution, of whom the study cohort comprised 52 (4%) with HER2+ breast cancer (median age, 64 years; range, 44-87). Nearly all had T1 tumors (98%; median size, 12 mm [range, 1-21 mm]). Most had estrogen receptor positive disease (88%), and all patients had negative surgical margins. Nearly all underwent sentinel node biopsy (94%), with the remainder undergoing no surgical axillary evaluation. Forty-two (81%) received chemotherapy; 40 (77%), hormone therapy; and 42 (81%), HER2-directed therapy, most commonly trastuzumab. At 143.8 person-years of follow-up (range, 7-226 months for each patient), we observed 2 LR events at 14 and 26 months, respectively, yielding a 2-year LR rate of 3.8%. No regional or distant recurrences were observed, nor were any breast-specific mortality events. Two deaths were observed, both without evidence of disease. Among a cohort of patients with HER2+ early-stage breast cancer managed with BCS and PBI, we observed a 2-year LR rate of 3.8%, with no regional or distant recurrences and excellent overall survival. These findings require confirmation with longer follow-up among larger cohorts but appear consistent with the excellent results of contemporary randomized trials of PBI unselected for HER2 status.