Radiation Oncology最新文献

Purpose: To investigate the early predictive value of dynamic magnetic resonance imaging (MRI)-based radiomics for progression and prognosis in locally advanced cervical cancer (LACC) patients treated with concurrent chemoradiotherapy (CCRT).

Methods and materials: A total of 111 LACC patients (training set: 88; test set: 23) were retrospectively enrolled. Dynamic MR images were acquired at baseline (MRI_pre), before brachytherapy delivery (MRI_mid) and at each follow-up visit. Clinical characteristics, 2-year progression-free survival (PFS), and 2-year overall survival (OS) were evaluated. The least absolute shrinkage and selection operator (LASSO) method was applied to extract features from MR images as well as from clinical characteristics. The support vector machine (SVM) model was trained on the training set and then evaluated on the test set.

Results: Compared with single-sequence models, multisequence models exhibited superior performance. MRI_mid-based radiomics models performed better in predicting the prognosis of LACC patients than the post-treatment did. The MRI_pre-, MRI_mid- and the ΔMRI_mid (variations in radiomics features from MRI_pre and MRI_mid) -based radiomics models achieve AUC scores of 0.723, 0.750 and 0.759 for 2-year PFS and 0.711, 0.737 and 0.789 for 2-year OS in the test set. When combined with the clinical characteristics, the ΔMRI_mid-based predictive model also performed better than the other models did, with an AUC of 0.812 for progression and 0.868 for survival.

Conclusion: We built machine learning models from dynamic features in longitudinal images and found that the ΔMRI_mid-based model can serve as a non-invasive indicator for the early prediction of prognosis in LACC patients receiving CCRT. The integrated models with clinical characteristics further enhanced the predictive performance.

Background: Local recurrence of rectal cancer (LRRC) previously treated with radiotherapy is associated with a poor prognosis. Historically, the integration of radiotherapy (RT) with surgery has improved the likelihood of complete resections (R0) and, consequently, enhanced survival. Unfortunately, many LRRC cases are not amenable to surgical intervention. The inclusion of chemotherapy (CHT) alongside advanced RT techniques including proton and carbon ion RT (CIRT) and stereotactic body radiation therapy (SBRT), has generated new treatment options. Therefore, there is a need for improved stratification of LRRC patients to enhance treatment outcomes. The RETRY is an integrated trial with the primary aim to explore if combining CHT with RT in all available modalities can enhance local control (LC) in LRRC patients, consequently improving survival.

Methods: Experts from Italian centers specializing in rectal cancer and LRRC management collaborated to design a prospective multicenter observational study within the AIRO group for gastrointestinal malignancies. Eligible participants are adult LRRC patients who previously had pelvic RT, meet specific criteria, and are affiliated with the participating Italian centers. Specific criteria must be met for CIRT referral. A total of 88 patients will be enrolled over three years. The primary objective is to determine the 3-year LC rate. Secondary outcomes include assessing survival, quality of life, and R0 resection rates in surgery cases. A minimum dose of 40 Gy, conventional fractionation with concomitant fluoropyrimidine-with/without oxaliplatin-based CHT (CRT) is prescribed in neoadjuvant setting. Alternatively, the dose will vary from 35 to 40 Gy in 5 fractions based on clinical judgment, by SBRT. Both proton and photon therapies will be evaluated in these approaches. Surgery will be considered if deemed operable. In inoperable cases, CIRT with a dose of 40-60 Gy relative biological effectiveness (RBE) will be administered with a daily dose fraction ranging between 3 and 4.8 Gy RBE.

Discussion: The RETRY trial aims to investigate the combined effects of RT and CHT and when feasible the addition of surgery, to determine whether this comprehensive approach can result in improved survival and quality of life for LRRC patients. Trial registration number ClinicalTrials.gov (No. NCT05984576).

Background: Rectal cancer patients are potential beneficiaries of adaptive radiotherapy (ART) which demands considerable resources. Currently, there is no definite guidance on what kind of patients and when will benefit from ART. This study aimed to develop and validate a methodology for estimating ART requirements in rectal cancer before treatment course.

Methods and materials: This study involved 66 rectal cancer patients from center 1 and 27 patients from center 2. The ART requirements were evaluated by comparing 8 dose volume histogram (DVH) metrics of targets and organs at risk (OARs) between planning and treatment fractions. Tolerance ranges of deviation of DVH metrics were derived from 10 patients and applied to assess fractional variability. Eighteen features, encompassing diagnostic, dosimetric, and time-related information, were utilized to formulate a stepwise logistic regression model for fraction-level ART requirement estimation. The super parameters were determined through 5-fold cross-validation with 250 training fractions and the methodology was validated with 109 internal testing fractions and 134 external testing fractions.

Results: The area under the curve (AUC) of training dataset was 0.74 (95% CI: 0.61 to 0.85), while in the internal and external testing, the AUC achieved 0.76 (95% CI: 0.60-0.90) and 0.68 (95% CI: 0.56-0.81). Using a best (or clinical applicable) cut-off value of 33.4% (11%), the predictive model achieved a sensitivity of 46.2% (69.2%) and specificity of 97.9% (68.7%). During the modeling, 5 features were retained: Homogeneity index (OR = 6.06, 95% CI: 2.93-14.8), planning target volume (OR = 1.77, 95% CI: 1.17-2.69), fraction dose (OR = 45.37, 95% CI: 5.74-469), accumulated dose (OR = 2.29, 95% CI: 1.35-4.14), and whether neoadjuvant chemoradiotherapy (OR > 1000).

Conclusion: ART requirements are associated with target volume, target dose homogeneity, fraction dose, dose accumulation and whether neoadjuvant radiotherapy. The predictive model exhibited the capability to predict fraction-level ART requirements.

Introduction: While there is a growing amount of data on the cardiac toxicity of radiotherapy (RT) in relation to its impact on cardiac sub-structures (CSS), there are only few studies addressing this issue in patients followed for esophageal cancer (ESOC). We aimed to evaluate the association between independent parameters of dose received by CSS and major cardiac events (MACEs) in this population.

Materials and methods: We retrospectively analyzed 122 patients treated with exclusive RT or chemo-RT for ESOC. Heart and CSS i.e. right atrium, left atrium (LA), right ventricle, left ventricle and myocardium, have been automatically segmented, and dose volume histogram were extracted. Cardiac events were collected focusing on the occurrence of MACEs of grade 3 or higher (G3+) and grade 4 or higher (G4+) according to the CTCAE v5.0.

Results: With a median follow-up of 21.9 months and in a population of high to very high cardiovascular risk (95.5%), 21 (17.2%) and 9 (7.4%) patients had G3 + and G4 + MACEs with a respective median time to event of 13.05 and 9.8 months. After multivariate analysis and among all heart and CSS-based dosimetric features, only the volume of LA receiving 15 Gy or more (V15LA) remained significantly associated with the G3 + and G4 + MACEs. The use of volumetric modulated arctherapy significantly reduced V15LA compared with 3D conformal RT.

Conclusion: In a cohort of ESOC patients treated with exclusive RT, incidence of MACEs was associated with V15LA, underlining the importance of CSS. These high cardiovascular (CV) risk patients should benefit from standard CV assessment and strict control of their risk factors.

Purpose: This study aims to investigate the prognostic impact of ground-glass opacity (GGO)-component in early-stage lung cancer patients treated with stereotactic body radiotherapy (SBRT).

Methods: From January 2013 to December 2022, 239 early-stage lung cancer patients (T1-2N0M0) underwent SBRT. They were categorized into two groups based on the presence of GGO-component: 65 patients in the subsolid group with a consolidation tumor ratio (CTR) between 0.25 and 1 and 174 patients in the solid group with a CTR of 1. Lung cancer-specific survival (LCSS) and progression-free survival (PFS) were analyzed using Cox regression models for both univariate and multivariate analyses to identify prognostic factors. Stabilized inverse probability of treatment weighting (IPTW) was employed for adjusting confounding factors. Recurrence incidence was assessed using competing risk analysis and compared using Gray's test.

Results: In the multivariate analysis, female, peripheral location, and subsolid nodules were favorable prognostic factors for LCSS; peripheral location, subsolid nodules, and adjuvant therapy were favorable prognostic factors for PFS. Between the subsolid (n = 65) and solid groups (n = 174), the median LCSS were not reached (p = 0.003), with 3-, 5-, and 9-year LCSS rates of 94.7% versus 80.3%, 90.9% versus 64.1%, 82.7% versus 53.5%, respectively. The median PFS were 72.5 months and 50.5 months (p = 0.030), with 3-, 5-, and 9-year PFS rates of 75.4% versus 61.2%, 56.6% versus 44.9%, 48.6% versus 23.3%, respectively. After stabilized IPTW (n = 240), the median LCSS were not reached (p = 0.024), with 3-, 5-, and 9-year LCSS rates of 94.0% versus 82.4%, 92.2% versus 67.7%, 85.3% versus 58.2%, respectively. The median PFS were 60.2 months and 50.5 months (p = 0.096), with 3-, 5-, and 9-year PFS rates of 73.8% versus 61.0%, 53.5% versus 46.2%, 46.8% versus 22.4%, respectively. The subsolid group had lower rates of locoregional recurrence (LRR) (10.4% vs. 25.9%, p = 0.035) and distant metastasis (DM) (17.1% vs. 37.9%, p = 0.064) compared to the solid group.

Conclusions: The presence of GGO-component in the lesion is an independent prognostic factor for LCSS and PFS. Subsolid nodules treated with SBRT demonstrated better prognosis, with significantly lower rates of local-regional recurrence. We should highlight GGO-component as a practical indicator for risk stratification of SBRT patients to guide treatment decisions.

Background: Laryngeal cancer is a common head and neck cancer. Surgical treatment can impair patients' voice and swallowing function, making definitive radiotherapy a viable alternative for locally advanced cases.

Methods: To compare the outcomes of definitive versus adjuvant radiotherapy in patients with primary locally advanced laryngeal cancer, we retrospectively evaluated consecutive patients treated from 2007 to 2020. We assessed and compared the median and 3-year overall survival (OS), disease-free survival (DFS), distant metastasis control (DMC), and local recurrence-free survival (LRC) in all patients and in T4 patients exclusively.

Results: One hundred patients were studied, including definitive (N = 64) and adjuvant (N = 36) radiotherapy. The median follow-up was 29 months. Overall, the median OS in the definitive vs. adjuvant group was 100 months (95%CI = 46.5-153.5) vs. not reached, respectively (log-rank P = 0.506). The median DFS in the definitive vs. adjuvant group was 20 months (95%CI = 7.7-32.3) vs. not reached, respectively (log-rank P = 0.148). Three-year OS and DFS rates in all patients were 64% (95%CI: 48-78) vs. 75% (95%CI: 55-95) and 43% (95%CI:29-57) vs. 61% (95%CI: 41-81) in the definitive vs. adjuvant groups, respectively. Among T4 patients, the median OS in the definitive RT group vs. adjuvant group was not reached vs. 48 (95%CI = 0-105.3), respectively (log-rank P = 0.788). The median DFS in the definitive RT group vs. adjuvant group was 12 months (95%CI = 9.34-14.65) vs. 36 months (95%CI = 4.4-67.5), respectively (log-rank P = 0.868). Three-year OS and DFS rates were 71% (95%CI: 42-100) vs. 75% (95%CI: 50-100) and 40% (95%CI:21-79) vs. 56% (95%CI: 25-87) in the definitive vs. adjuvant groups, respectively.

Conclusions: Our analysis suggests that definitive radiotherapy in laryngeal cancer does not lead to a poorer outcome than total laryngectomy followed by adjuvant radiotherapy. In T4 patients, our findings should reassure clinicians and patients about the viability of definitive radiotherapy as a treatment approach.

Purpose: The purpose of this study was to quantify the intra- and interfraction motion of the target volume and organs at risk (OARs) during adaptive radiotherapy (ART) for uterine cervical cancer (UCC) using MR-Linac and to identify appropriate UCC target volume margins for adapt-to-shape (ATS) and adapt-to-position (ATP) workflows. Then, the dosimetric differences caused by motion were analyzed.

Methods: Thirty-two UCC patients were included. Magnetic resonance (MR) images were obtained before and after each treatment. The maximum and average shifts in the centroid of the target volume and OARs along the anterior/posterior (A/P: Y axes), cranial/caudal (Cr/C: Z axes), and right/left (R/L: X axes) directions were analyzed through image contours. The bladder wall deformation in six directions and the differences in the volume of the organs were also analyzed. Additionally, the motion of the upper, middle and lower rectum was quantified. The correlation between OAR displacement/deformation and target volume displacement was evaluated. The planning CT dose distribution was mapped to the MR image to generate a plan based on the new anatomy, and the dosimetric differences caused by motion were analyzed.

Results: For intrafraction motion, the clinical tumor volume (CTV) range of motion along the XYZ axes was within 5 mm; for interfraction motion, the range of motion along the X axis was within 5 mm, and the maximum distances of motion along the Y axis and Z axis were 7.45 and 6.59 mm, respectively. Additionally, deformation of the superior and anterior walls of the bladder was most noticeable. The largest magnitude of motion was observed in the upper segment of the rectum. Posterior bladder wall displacement was correlated with rectal and CTV centroid Y-axis displacement (r = 0.63, r = 0.50, P < 0.05). Compared with the interfractional plan, a significant decrease in the planning target volume (PTV) D98 (7.5 Gy, 7.54 Gy) was observed. However, there were no significant differences within the intrafraction.

Conclusion: During ART for UCC patients using MR-Linac, we recommend an ATS workflow using isotropic PTV margins of 5 mm based on intrafraction motion. Based on interfraction motion, the recommended ATP workflow uses anisotropic PTV margins of 5 mm in the R/L direction, 8 mm in the A/P direction, and 7 mm in the Cr/C direction to compensate for dosimetric errors due to motion.

Background and purpose: This study evaluates the dosimetric impact of tumor matching (TM) and bone matching (BM) in carbon ion radiotherapy for locally advanced non-small cell lung cancer.

Materials and methods: Forty patients diagnosed with locally advanced non-small cell lung cancer were included in this study. TM and BM techniques were employed for recalculation based on re-evaluation computed tomography (CT) images of the patients, resulting in the generation of dose distributions: Plan-T and Plan-B, respectively. These distributions were compared with the original dose distribution, Plan-O. The percentage of the internal gross tumor volume (iGTV) receiving a prescription dose greater than 95% (V95%) was evaluated using dose-volume parameters. Statistical analysis was performed using a paired signed-rank sum test. Additionally, the study investigated the influence of tumor displacement, volume changes, and rotational errors on target dose coverage.

Results: The median iGTV V95% values for the Plan-O, Plan-T, and Plan-B groups were 100%, 99.93%, and 99.60%, respectively, with statistically significant differences observed. TM demonstrated improved target dose coverage compared to BM. Moreover, TM exhibited better target coverage in case of larger tumor displacement. TM's increased adjustability in rotation directions compared to BM significantly influenced dosimetric outcomes, rendering it more tolerant to variations in tumor morphology.

Conclusion: TM exhibited superior target dose coverage compared to BM, particularly in cases of larger tumor displacement. TM also demonstrated better tolerance to variations in tumor morphology.

Background: The use of stereotactic body radiotherapy (SBRT) to definitively treat oligometastases in prostate cancer has drawn large clinical and research interests within radiation oncology. However, the evidence is considered in its early stages and there is currently no systematic review of randomized controlled trials (RCTs) in this field. We aimed to evaluate the efficacy and safety of SBRT as metastasis-directed therapy (MDT) in oligometastatic prostate cancer (OMPC) compared to no MDT reported in RCTs.

Methods: MEDLINE, Embase, CINAHL Complete, and Cochrane Library were searched on October 28, 2023. Eligible studies were RCTs comparing SBRT as MDT with no MDT in extracranial OMPC, without restrictions on follow-up time, publication status, language, or year. Participant subsets fulfilling the eligibility criteria were included. Critical outcomes were overall survival and grade ≥ 3 toxicity, and additional important outcomes were progression-free survival (PFS), local control, grade 5 toxicity, health-related quality of life, and systemic therapy-free survival. Meta-analyses were planned. Risk of bias was assessed using the Cochrane risk-of-bias tool version 2, and the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation.

Results: In total, 1825 unique study reports were identified and seven phase II RCTs with 559 eligible participants were included. Four trials included multiple types of primary cancer. Outcome definitions were heterogeneous except for overall survival and toxicity. For overall survival, only one study reported events in both arms. Meta-analysis of the grade ≥ 3 toxicity results from two trials showed no difference (pooled risk ratio 0.78, 95% confidence interval 0.37-1.65, p = 0.52). Four trials reported significantly longer PFS, with a pooled hazard ratio of 0.31 (95% confidence interval 0.21-0.45, p < 0.00001). Risk of bias was of some concerns or high. Quality of evidence was low or moderate.

Conclusions: Phase II trials have shown promising improvements in PFS for several OMPC states without excess toxicity. Overall survival comparisons are immature. In future confirmatory phase III trials, adequately large sample sizes, blinding of outcome assessors, and/or increased adherence to assigned intervention could improve the quality of evidence. PROSPERO registration number: CRD42021230131.

Background/aim: Current approaches for locally advanced rectal cancer (LARC) typically recommend neoadjuvant chemoradiotherapy (nCRT) with 5-fluorouracil (5FU) or its oral analogs followed by surgery as the standard of care. However, the question of whether intensifying concurrent chemotherapy by adding oxaliplatin to the 5FU-based backbone can yield better outcomes remains unresolved. This study aimed to investigate the benefits of incorporating oxaliplatin into fluoropyrimidine-based chemoradiotherapy (CRT) to increase locoregional control and survival.

Methods: Among 290 patients with LARC admitted to the Iran Cancer Institute's radiation oncology department between January 2008 and December 2019, 29 received CAPEOX (capecitabine 625 mg/m²/bid on RT days and weekly oxaliplatin 50 mg/m²), whereas 293 received capecitabine (825 mg/m² twice daily or rarely 5FU in the first 4 days and last week of radiotherapy (RT)). Variables potentially affecting treatment outcomes were used for propensity score matching. Kaplan‒Meier and log-rank tests were employed for overall survival (OS) and disease-free survival (DFS) analyses and were adjusted with propensity score matching.

Results: Data from 29 patients who received CAPEOX and 216 patients who received capecitabine were analyzed after propensity score matching without replacement. After propensity score matching, in the multivariate analysis, CAPEOX significantly increased the likelihood of achieving a pathologic complete response (pCR) by 4.38 times (CI: 1.90-10.08, p value < 0.001). However, CAPEOX did not demonstrate any statistically significant predictive value for DFS (P = 0.500) or OS (P = 0.449).

Conclusion: The addition of oxaliplatin resulted in a significantly higher rate of pCR without any translation into long-term survival outcomes.