Radiotherapy For Cancer Research Articles

Auto-segmentation of surgical clips for target volume delineation in post-lumpectomy breast cancer radiotherapy

PurposeTo develop an automatic segmentation model for surgical marks, titanium clips, in target volume delineation of breast cancer radiotherapy after lumpectomy.MethodsA two-stage deep-learning model is used to segment the titanium clips from CT image. The first network, Location Net, is designed to search the region containing all clips from CT. Then the second network, Segmentation Net, is designed to search the locations of clips from the previously detected region. Ablation studies are performed to evaluate the impact of various inputs for both networks. The two-stage deep-learning model is also compared with the other existing deep-learning methods including U-Net, V-Net and UNETR. The segmentation accuracy of these models is evaluated by three metrics: Dice Similarity Coefficient (DSC), 95% Hausdorff Distance (HD95), and Average Surface Distance (ASD).ResultsThe DSC, HD95 and ASD of the two-stage model are 0.844, 2.008 mm and 0.333 mm, while their values are 0.681, 2.494 mm and 0.785 mm for U-Net, 0.767, 2.331 mm and 0.497 mm for V-Net, 0.714, 2.660 mm and 0.772 mm for UNETR. The proposed 2-stage model achieved the best performance among the four models.ConclusionWith the two-stage searching strategy the accuracy to detect titanium clips can be improved comparing to those existing deep-learning models with one-stage searching strategy. The proposed segmentation model can facilitate the delineation of tumor bed and subsequent target volume for breast cancer radiotherapy after lumpectomy.

Dermatitis during adjuvant irradiation for breast cancer (DAI-BREAC): a randomized controlled trial investigating whether grade ≥2 dermatitis during radiotherapy for breast cancer can be reduced by a mobile application that reminds patients to perform skin care

BackgroundRadiotherapy of breast cancer can be associated with dermatitis. Grade ≥2 radiation dermatitis can be painful and impair the patients’ quality of life. To reduce the risk of this complication, patients have to perform skin care several times each day. This may require a considerable level of compliance. This randomized DAI-BREAC trial investigates whether a mobile application reminding the patients four times per day to perform skin care (reminder app) will contribute to reduction of grade ≥2 radiation dermatitis.MethodsThis multinational, randomized, active-controlled, parallel-group, multicenter trial compares standard skin care supported by a reminder app (Arm A) versus standard skin care alone (Arm B) regarding grade ≥2 radiation dermatitis in patients receiving adjuvant radiotherapy for breast cancer. The effect of the app will be considered clinically relevant, if the rate of grade ≥2 radiation dermatitis is reduced from 25.4% (rate identified in a preceding study) to 15%. A total of 134 patients per arm including drop-outs are required. Secondary aims include pain (visual analogue scale), patient satisfaction with the app (questionnaire), impact of the app on the use of health technology (questionnaire), and benefit from support (coaching) by staff members regarding the use of the app (questionnaire).DiscussionIf the reminder app contributes to a decrease of grade ≥2 radiation dermatitis in patients irradiated for breast cancer, it will likely become a useful instrument for these patients.Trial registrationClinicaltrials.gov (NCT06483477; URL: https://clinicaltrials.gov/show/NCT06483477). Registered on 1st of July, 2024. First patient was included in December 2024.

Accelerated Aging in Survivors of Childhood Cancer—Early Onset and Excess Risk of Chronic Conditions

The lifetime risk of aging-related diseases among survivors of childhood cancer, accelerated by cancer treatment exposures, is unknown. Understanding this risk can provide a more comprehensive assessment of long-term health across the lifespan of survivors and guide adult care. To estimate the lifetime risks of 8 treatment-related cancers and cardiovascular conditions among childhood cancer survivors and compare them with the general population. Using data from the Childhood Cancer Survivor Study and national databases, this simulation modeling study projected long-term outcomes for 5-year survivors diagnosed between 1970 and 1999 based on treatment exposures and age-related risks. The general population comparator was simulated using age-, sex-, and calendar year-matched individuals who faced only age-related risks. Treatment era (1970s, 1980s, 1990s), original cancer diagnosis, radiation treatment for primary diagnosis (any, none). Estimated lifetime risks of 8 health conditions (breast cancer, colorectal cancer, glial tumors, sarcomas, heart failure, coronary heart disease/myocardial infarction, stroke, and valvular disease). Risks were projected and compared with the general population, stratified by radiation exposure. In the general population, 20% developed at least 1 health condition by age 65.0 years; in 5-year survivors this threshold was reached at age 47.3 years, representing a 17.7-year (95% uncertainty interval [UI], 14.0-21.0) acceleration in disease onset. By age 65 years, 55% of survivors were projected to develop at least 1 condition, indicating a 2.7-fold (95% UI, 2.2-3.5) higher relative risk and 34.2% (95% UI, 28.3-42.5) absolute excess risk compared with the general population. Risks were higher among those treated with radiation therapy for childhood cancer (22.0 years earlier onset [95% UI, 18.0-25.0]; 37.3% excess risk [95% UI, 31.6%-44.7%]) but still elevated for those without radiation exposure (13.5 years earlier onset [95% UI, 10.0-16.0]; 31.0% excess risk [95% UI, 23.9%-40.3%]). Reaching middle age was still associated with increased health risks. Compared with the general population, survivors who reached age 40 years had a 6.2-fold higher risk (95% UI, 4.8-9.4) of developing a new condition within 10 years. This study found that survivors of childhood cancer experience accelerated onset of aging-related diseases, regardless of prior radiation exposure. These findings underscore the importance of prioritizing cancer and cardiovascular disease prevention among survivors decades earlier than for the general population.

Predictive value of pretreatment peripheral blood N/CD4 and N/CD8 ratios for the efficacy of radiotherapy for esophageal cancer.

This study aimed to explore the predictive value of pretreatment peripheral blood immune cell subsets in analyzing the outcomes of patients who underwent radiation therapy for esophageal cancer at their first visit. This study included 72 patients with esophageal cancer (EC) treated at Jiangsu University Hospital from December 2021 to December 2023. Among them, 48 were males and 24 were females, with a median age of 64 years (range: 52-98 years). Comprehensive clinical data, laboratory results, and imaging findings were collected to analyze survival differences. The log-rank test was used for univariate analysis to assess the sensitivity of these patients to radiotherapy. The statistically significant and clinically relevant factors identified from the univariate analysis were subsequently incorporated into a Cox proportional hazards regression model for multivariate analysis to investigate the associations between pretreatment peripheral blood immune cell subsets and patient survival. Univariate Cox regression analysis revealed that the Eastern Cooperative Oncology Group (ECOG) score, CD4+ T-cell ratio, neutrophil-to-CD4+ T-cell ratio (N/CD4), neutrophil-to-CD8+ T-cell ratio (N/CD8), and neutrophil-to-B-cell ratio (N/B) were significantly correlated with survival outcomes in patients receiving radiotherapy for tumors. Furthermore, multivariate Cox regression analysis identified N/CD4+ T cells and N/CD8+ T cells as critical prognostic indicators for these patients. Receiver operating characteristic curve analysis was employed to evaluate the work characteristics of the subjects, resulting in area under the curve values of 0.763 for both N/CD4 and N/CD8. The analysis also revealed that the optimal cutoff values for N/CD4+ T cells and N/CD8+ T cells were 0.01053329 and 0.01184294, respectively. N/CD4 and N/CD8 have emerged as viable prognostic predictors for patients undergoing radiotherapy for EC, offering valuable insights for clinicians to strategize further treatment options. However, the retrospective nature of this study introduces potential bias in assessment, underscoring the necessity for large-scale, prospective, randomized controlled trials to substantiate and validate these findings.

Leveraging technology and standardized institutional practices to mitigate disparities in breast cancer radiation therapy.

Disparities in various dimensions, includingracial, in breast cancer treatment and outcomes are well established. A recent multi-institutional study reported a higher mean heart dose (MHD) in Black and minority women compared to White women who underwent left-sided breast/chest wall irradiation which translated into excess cardiac events and mortality. We evaluated the MHD of women treated in our institution and investigated whether institution-wide measures including the use of readily available but inconsistently adopted technologies can mitigate this disparity. We identified 509 female patients treated with left-sided breast/chest wall irradiation with/without regional nodal irradiation (RNI). Details regarding cardiac dosimetry, deep-inspiratory breath-hold (DIBH) such as active breathing coordinator (ABC) use, breast size, internal mammary nodal (IMN) irradiation, and whether the treatment plan met boarding pass requirements and was peer reviewed were noted. MHD differences across racial groups were analyzed using Kruskal-Wallis test, while UVA and MVA linear regression analyses assessed influence of various factors on MHD. MHD(Gy) was similar across racial groups; 1.38, 1.35, and 1.39 (p = 0.6) in Black, White, and other racial groups, respectively. Utilization of hypofractionation, cavity boosts, RNI, IMN irradiation, meeting boarding pass requirements, and peer review were similar. ABC usage (%) was 83/75/62 (p = 0.005), while median breast size(cc) was 1504/1904/1331 (p = 0.001) in White/Black/other women, respectively. On UVA and MVA, MHD differed with IMN treatment, boost and ABC use but not racial groups and varying breast sizes. Despite anatomical differences such as breast size, achieving similar cardiac dose is feasible across racial groups by uniformly utilizing appropriate technology such as ABC,with standardized boarding pass constraints, and peer review of all cases. Further studies to identify factors that may cause varied cardiac morbidity rates despite similar cardiac dosimetry among racial groups are warranted.

Arm-Behind-the-Back Position for Breast Cancer Radiotherapy in Patients with Lupus Erythematosus and Shoulder Arthropathy: A Case Report

Arm-Behind-the-Back Position for Breast Cancer Radiotherapy in Patients with Lupus Erythematosus and Shoulder Arthropathy: A Case Report

Clinical and Genomic Characterization of Secondary Rectal Cancer After Radiotherapy for Prostate Cancer

Patients treated with radiotherapy (RT) for prostate cancer (PC) have increased risk of secondary rectal cancer (SRC) and more limited treatment options. To assess the tumor molecular profile, clinical characteristics, and oncologic outcomes of SRC after PC and compare them with those of primary rectal cancer (PRC). This case-control study included patients with SRC diagnosed 5 or more years after RT for PC and patients with PRC who were treated at Memorial Sloan Kettering Cancer Center in New York between February 1, 1994, and September 31, 2022. Clinical information and DNA sequencing data were analyzed. Oncologic outcomes were compared between patients with SRC and clinically matched patients with PRC using log-rank tests and Cox proportional hazards regression models. Numerical and categorical variables were compared using the Wilcoxon rank sum test and Fisher exact test, respectively. The analysis included 604 male patients with PRC (71.6%; median age, 55 [IQR, 46-66] years) and 64 male patients with SRC (median age, 78 [IQR, 72-82] years). Patients with SRC had more distal rectum (37 of 63 [58.7%] vs 131 of 581 [22.5%]; P < .001) and anterior rectal wall (20 of 57 [35.1%] vs 67 of 496 [13.5%]; P < .001) tumors, were less likely to receive neoadjuvant treatment (33 of 64 [51.6%] vs 570 of 604 [94.4%]), and had shorter 5-year overall survival (45.7% vs 64.9%; P = .01) and disease-free survival (40.3% vs 71.2%; P = .006) compared with clinically matched patients with PRC. Targeted DNA sequencing data from 31 SRC tumors identified lower mutational burden (median, 4.4 [IQR, 3.2-6.7] per megabase [Mb] vs 5.8 [IQR, 4.4-7.0] per Mb; P = .047), lower frequency of APC alterations (15 [48.4%] vs 432 [79.9%]; P < .001), and higher rates of SMAD4 inactivation (8 [25.8%] vs 54 [10.0%]; P = .01) compared with 541 PRC tumors. Whole-exome sequencing data from 17 SRC tumors identified a higher rate of frameshift deletions compared with 28 PRC tumors (median, 5.0 [IQR, 4.0-9.0] vs 2.5 [IQR, 1.0-4.2] variants; P < .001). In this case-control study, patients with SRC after RT for PC had worse survival and different molecular profiles than patients with PRC. These findings may help improve the clinical management of SRC.

Incidence and predictors of lower extremity lymphedema after postoperative radiotherapy for prostate cancer

BackgroundTo assess the rate and predictors of lower extremity lymphedema (LEL) after radiotherapy (RT) following radical prostatectomy (RP) ± pelvic lymph node dissection (PLND) for prostate cancer.MethodsPatients (pts) treated with adjuvant or salvage RT after RP ± PLND and a minimum 2-year follow-up were included. LEL was defined as a volume difference ≥ 10% between limbs evaluated using circumferential measurements with a flexible non-stretch tape. The following predictors were investigated at logistic regression: age (continuous); body mass index (BMI, continuous); exercise level (low vs. medium/high); smoking (yes vs. no); cigarette pack/year (continuous); hypertension (yes ns no); vascular comorbidity (yes vs. no); diabetes (yes vs. no); PLND (yes vs. no); number of examined nodes (continuous); whole pelvis radiotherapy (WPRT) (yes vs. no); time between RP and RT (continuous); planning target volume (PTV) volume (continuous); PTV/BMI (continuous). Statistical significance was claimed for p < 0.05.Results101 pts were examined. The median time from surgery to RT was 36.1 months (mths) (IQR: 15.0-68.3), the median time from RT to the date of study examination was 51.1 months (IQR: 36.8–65.3). 14 pts developed LEL (13.9%), 3 pts (2.9%) before RT, 11 pts (10.8%) after RT. The median time from RT to LEL was 4 mths (IQR: 0.5–17.3). At multivariable analysis (MVA) diabetes mellitus (DM) (OR = 32.8, p = 0.02), time between surgery and RT (OR = 0.966, p = 0.039) and exercise (OR = 0.03, p = 0.002) were independently correlated to LEL. The number of examined nodes was highly correlated to LEL at univariate analysis (OR = 1.066, p = 0.025) but was not confirmed at MVA (p = 0.719). Interestingly, the distribution of the examined nodes was statistically different between pts with low (median N = 12) vs. medium/high (N = 5) exercise (p = 0.034).ConclusionsClinically detectable LEL involves a minority of pts after RT. DM is a predisposing factor, while awaiting RT delivery has a protective effect favoring salvage over adjuvant RT.

Adaptive radiotherapy triggering for nasopharyngeal cancer based on Bayesian decision model.

To develop a Bayesian decision model for adaptive radiotherapy (ART) in nasopharyngeal cancer (NPC) that balances clinical capacity of ART and inter-fraction dosimetric changes.&#xD;&#xD;Materials and Methods: A retrospective analysis was conducted on 84 fractions from 17 NPC patients treated with intensity-modulated radiotherapy (IMRT) using a CT-Linac. Fourteen patients were included for the model construction, and three for validation. Daily diagnostic-level CT images were rigidly registered to the planning CT for regions of interest (ROIs) and treatment plan propagation. The propagated contours were reviewed and refined by radiation oncologists. For each daily CT, percentage differences in 27 dose metrics were compared to the original plan. Composite scores of dose differences were developed using factor analysis on planning target volume (PTV) and organ at risk (OAR) dose metrics. These scores were integrated into a Bayesian decision model, which incorporated a subjective trigger rate to determine the initiation of ART.&#xD;&#xD;Results: The model generated individualized re-plan strategies based on composite scores for PTV or OAR, with trigger rates ranging from 10% to 60%. In the validation with 14 fractions, significant anatomical and dosimetric variations were identified. At a 30% trigger rate, only one fraction was misclassified.&#xD;&#xD;Conclusion: It is feasible to employ a Bayesian decision model for adaptive radiotherapy, merging subjective clinical insights with objective dosimetric data to refine re-planning decisions.&#xD.

Moderately hypofractionated radiotherapy for prostate cancer in an era of SBRT and focal boosting.

Moderately hypofractionated radiotherapy for prostate cancer in an era of SBRT and focal boosting.

Diagnostic image-based treatment planning for online adaptive ultra-hypofractionated prostate cancer radiotherapy with MR-Linac.

A new workflow was investigated for Elekta Unity MR-Linac by removing the computed tomography (CT)-simulation step and using diagnostic CT (DCT) for reference plan generation. Ten patients with ultra-hypofractionated prostate cancer treated with magnetic resonance imaging (MRI)-guided adaptive radiotherapy were retrospectively enrolled. Targets and organs at risk (OARs) were recontoured on DCT, and Hounsfield unit conversions to relative electron density were calibrated for DCT. Reference plans were reoptimized and recalculated using DCT for Unity. Subsequent adaptive plans were designed through an adapt-to-shape workflow to edit targets and OARs via daily MRI to generate a new treatment plan. Bulk electron density information for Unity adaptive plan was compared between planning CT (PCT) and DCT for volumes of interest. Dosimetric parameters were evaluated between PCT- and DCT-based reference and adaptive plans for target coverage and OAR dose constraints. Bulk relative electron density differences between PCT and DCT were within±1% for targets and OARs, excepting the rectum. PCT and DCT-based reference plans did not significantly differ in mean target coverages or for OARs in dosimetric difference except for V36Gy of the rectum. PCT- and DCT-based adaptive plans did not significantly differ for most dosimetric parameters of targets and OARs except for V29Gy and V36Gy of the rectum, V18.1Gy of the bladder, and D50% of the urethra. By removing the CT simulation step, it is feasible to use DCT for designing reference and adaptive plans in the Unity ATS workflow. The workflow increased adaptive radiotherapy efficiency and decreased patient waiting time and additional radiation dose.

Optimizing fractionation schedules for de-escalation radiotherapy in head and neck cancers using deep reinforcement learning.

Optimizing fractionation schedules for de-escalation radiotherapy in head and neck cancers using deep reinforcement learning.

Single-cell RNA sequencing revealed changes in the tumor microenvironment induced by radiotherapy for cervical cancer and the molecular mechanism of mast cells in immunosuppression.

Radiotherapy (RT) is an important treatment for cervical cancer (CC), effectively controlling tumor growth and improving survival rates. However, radiotherapy-induced cell heterogeneity and its underlying mechanisms remain unclear, which may potentially impact treatment efficacy. This study aims to investigate tumor microenvironment changes following radiotherapy for CC, hoping to provide evidence to improve the therapeutic effects of radiotherapy. For the first time, we applied single-cell RNA sequencing (scRNA-seq) to analyze tissue samples from three CC patients pre- and post-radiotherapy. We obtained gene expression data from 52,506 cells to identify the cellular changes and molecular mechanisms induced by radiotherapy. Radiotherapy significantly alters cellular composition and gene expression within the tumor microenvironment (TME), notably upregulating mast cell expression. Mast cells are involved in multiple cell axes in the CC ecosystem after radiotherapy, and play a pivotal role in tumor immunosuppression and matrix remodeling. scRNA-seq revealed gene expression variations among cell types after radiotherapy, underscoring the importance of specific cell types in modulating the TME post-treatment. This study revealed the molecular mechanism of radiotherapy for CC and the role of mast cells, providing a foundation for optimizing the personalized treatment of CC.

Multimodality immunotherapy with avelumab, short-course radiotherapy, and cyclophosphamide in head and neck cancer: the CONFRONT phase I-II trial.

Multimodality immunotherapy with avelumab, short-course radiotherapy, and cyclophosphamide in head and neck cancer: the CONFRONT phase I-II trial.

Postoperative radiotherapy improves long-term survival in HER2-positive metastatic breast cancer: real-world evidence from the latest SEER database.

To evaluate the role of Postoperative Radiotherapy (PORT) in HER2-positive metastatic breast cancer (MBC) in the context of targeted therapy and clarify the subgroups that may benefit from PORT. Clinical data of female patients with HER2-positive MBC from the surveillance, epidemiology, and end results (SEER) database for the years 2016-2020 were collected according to established inclusion and exclusion criteria. The impact of PORT on patient survival was assessed, and subgroup analyses were performed to identify populations with potential benefits from PORT. A total of 541 patients from the SEER database were included in the analysis. The 3-year overall survival (OS) of the PORT group was significantly higher than that of the non-PORT group. (86.7% vs. 80.2%, P = 0.011). Multivariate analysis revealed that race and PORT were independent prognostic factors. Black patients and those who received PORT had longer overall survival (OS) (P < 0.05). Subgroup analysis suggested that PORT further improved OS in patients with mastectomy, advanced TN stage, high tumor grade, positive hormone receptor status, and multiple metastatic organs (P < 0.05). PORT further improves the survival of HER2-positive MBC. Subgroup analysis suggests that patients with locally advanced stage (T3-4, N2-3), Grade III, HR-positive status, bone-and-visceral metastasis, and those who have undergone mastectomy benefit significantly.

Radiation-induced lymphocyte apoptosis and chromosomic aberrations for prediction of toxicities in patients undergoing radical radiotherapy for breast or prostate cancers.

Radiation-induced lymphocyte apoptosis (RILA) and chromosomal damage assays (CDA) assays are proposed predictors of radiotherapy (RT) adverse events (RTAE). This study evaluated RILA and CDA in patients undergoing different RT dose regimens for early breast (FAST trial) or prostate (CHHiP trial) cancer. Consecutive patients were recruited from each trial. Fresh heparinised blood samples were analyzed for RILA and CDA. The primary endpoint was time to first change in photographic breast appearance (FAST) or time to first grade ≥2 RTOG bladder or bowel toxicity (CHHiP). The secondary endpoint in FAST was breast fibrosis. The dataset included 103 FAST and 297 CHHiP trial patients. No significant association of RILA with the primary endpoint was observed in the FAST trial. However, the risk of grade ≥2 breast fibrosis was lower in patients with RILA ≥24% compared to those with RILA ≤16% (p = 0.012). In the CHHiP trial, no significant associations were found between CDA after prostate radiotherapy outcomes. However, higher levels of micronuclei per cell were associated with a lower risk of grade ≥2 RTOG pelvic toxicities. The relative risk of developing grade ≥2 RTAE decreased for patients with RILA ≥ 24% but was not statistically significant. No association was found between RILA and photographic breast appearance. High RILA values were statistically associated with a lower risk of grade ≥2 breast fibrosis. In the CHHiP trial, most assays showed no association with pelvic toxicities. RILA is confirmed as a potential predictor of breast fibrosis regarding fraction sizes.

Long Term Results of a Phase II Study of Adjuvant Proton Radiotherapy for Node-Positive Cancer of the Uterus and Cervix: Proton Radiation for Uterine/Cervical Cancer.

Long Term Results of a Phase II Study of Adjuvant Proton Radiotherapy for Node-Positive Cancer of the Uterus and Cervix: Proton Radiation for Uterine/Cervical Cancer.

Establishing a deep learning model that integrates pre- and mid-treatment computed tomography to predict treatment response for non-small cell lung cancer.

Establishing a deep learning model that integrates pre- and mid-treatment computed tomography to predict treatment response for non-small cell lung cancer.

AI-enhanced cancer radiotherapy quality assessment: utilizing daily linac performance, radiomics, dosimetrics, and planning complexity

AI-enhanced cancer radiotherapy quality assessment: utilizing daily linac performance, radiomics, dosimetrics, and planning complexity

Respiratory muscle training reduces painful swallowing and opioid use during radiation therapy for head and neck cancer: a matched pair analysis

BackgroundPatients with head and neck cancer (HNC) receiving radiation therapy (RT) are at increased risk for symptoms of oral mucositis (OM), opioid use, and declines in physical function, outcomes that contribute to increased morbidity and mortality. The study objective was to determine the effects of respiratory muscle training (RMT) on OM and opioid use, as well as functional performance in patients with HNC receiving RT with or without concurrent chemotherapy (CCRT).MethodsPatients aged ≥ 18 years of age with stage I to IV HNC being treated with RT or CCRT receiving a home-based respiratory muscle training (RMT) (n = 20) were compared to a 5:1 matched historical group (n = 100) who did not receive RMT. RMT was delivered using the commercially available Power Lung AireStream device (Houston, TX) via a standardized home-based inspiratory and expiratory muscle-training program requiring ~ 20–30 min/day, five days per week, with a progressively increasing workload. Primary endpoints collected from all patients included changes in OM symptoms and use of opioids for pain control following start of RT. Secondary outcomes collected on RMT patients included respiratory muscle strength and functional performance (Six-Minute Walk Test, 6MWT; Short Physical Performance Battery, SPPB). All measures were assessed before and within 1–2 weeks following a standard 7-week RT regimen.ResultsRMT reduced the impact of self-reported swallowing soreness (p = 0.032), eating soreness (p = 0.036), and opioid use (p = 0.015). RMT maintained inspiratory muscle strength (+ 0.6 ± 18 cmH2O, p = 0.87), expiratory muscle strength (+ 0.7 ± 12.7 cmH2O, p = 0.197), and improved the 6MWT (+ 20 ± 39.9 m, p = 0.025), with no change in the SPPB total score (p = 0.262).ConclusionsRMT is a low-cost intervention that is easy to perform among patients undergoing RT/RTCC for HNC and is likely to reduce OM pain/symptoms and opioid, as well as to preserve respiratory muscle strength and physical function during cancer treatment.Trial registrationNot applicable. This was a matched retrospective cohort study not registered as it was a nonrandomized trial with a historical control group.