Radiation Oncology最新文献

Background: Specific congenic mice derived from inbred C3H/HeJ mice, which present early onset pneumonitis, and C57BL/6J mice manifesting later onset pneumonitis with pulmonary fibrosis, vary in time to respiratory distress from these responses following whole thorax irradiation.

Methods: Herein, to investigate a potential adaptive immunity contribution to lung disease in this model, we used flow cytometry to enumerate the pulmonary lymphocytes of C3H/HeJ, C57BL/6J and three lines of sub/congenic mice, at respiratory distress from 18 Gy whole thorax irradiation and in strain matched controls.

Results: CD4 + lymphocyte % of C3H/HeJ mice exceeded that of C57BL/6J mice at both radiation-induced respiratory distress and in unirradiated controls (P < 0.04) and pulmonary CD4+% was reduced, at distress relative to control levels, in fibrosis responding strains. CD8 + lymphocyte % was reduced in distressed mice, compared to controls, for 8 of 10 comparisons by strain and sex including those of both pneumonitis and pneumonitis with fibrosis responses. γδ + lymphocyte % was largely unchanged at distress from control levels. Time to radiation-induced respiratory distress, and strain fibrosis score, were each negatively correlated with pulmonary CD4+%, and with the CD4/CD8 ratio, measured in distressed mice (r<-0.76; P < 0.01) or in unirradiated controls (r<-0.75; P < 0.02). Inclusion of the lymphocyte profile of unirradiated mice of a separate C3H/HeJ and C57BL6/J-derived congenic line, named Radpf1 and known to be spared radiation-induced lung disease, yielded a pulmonary CD4+% correlation with time to respiratory distress of (r = 0.16, P = 0.76) and of (r=-0.83; P = 0.04) for strain fibrosis score.

Conclusions: Pulmonary lymphocyte profiling revealed strain-dependent %CD4 + lymphocytes, measured in mice manifesting radiation-induced respiratory distress or in untreated controls, to correlate with fibrotic lung disease in this mouse model.

Background: Adaptive radiotherapy (ART) is an advanced form of image-guided radiotherapy that involves the re-contouring and re-planning of a patient's treatment plan, either while the patient is on the table (online) or in between fractions (offline). ART allows for the adjustment of a treatment plan to respect a patient's changes in internal anatomy, something that is critical in the treatment of gastrointestinal (GI) malignancies in which the mobile and radiosensitive GI tract plays a key role in driving toxicity. Herein we review the indications for both online and offline ART in GI cancers.

Main text: Online ART plays a critical role in the treatment of pancreatic cancer when using stereotactic body radiotherapy (SBRT). A variety of ART workflows have demonstrated that ART allows for the safe dose-escalated treatment of locally advanced pancreatic cancer. In addition to pancreatic cancer, there are now a bevy of data demonstrating that ART plays a key role in the treatment of liver cancers and abdominal oligometastases when using SBRT and allows for the safe delivery of single-fraction abdominal SBRT. While lower GI cancers are generally not treated with SBRT-like doses, both online and offline ART workflows have been shown to potentially reduce toxicity in patients with anal and rectal cancers. Improved integration of artificial intelligence and direct-to-unit workflows in ART hold promise that the overall process can become more efficient, allowing for more widespread adoption in GI radiation oncology.

Conclusions: ART is an expanding radiotherapy paradigm in which a patient's treatment plan is adjusted to match observed changes in patient anatomy and has been successfully incorporated into the treatment of a variety of GI cancers. The successful implementation of workflows in pancreatic cancer, liver cancers, and lower GI cancers, amongst others, as well as incorporation into multi-center clinical trials, suggest that ART will continue to play a critical role of GI radiation oncology for years to come. As improvements in efficiency and access allow for increasing use of ART world-wide, we predict that ART will continue to play a critical part in the management of patients with GI malignancies.

Background: Oral stents may reduce toxicities during radiation therapy for head and neck cancer (HNC). Customized 3D-printed oral stents offer faster production and achieve comparable patient-reported outcomes to conventionally fabricated stents. However, their design process remains time-consuming, lacks standardization, and relies heavily on skilled technicians. We hypothesized that semi-automating the design process for 3D-printed, mouth-opening, tongue-depressing (MOTD) stents could standardize the design workflow and decrease design time.

Methods: Using oral stent design principles established over decades by oral oncologists, we created a customized computer program (Autostent) using MATLAB to semi-automate the design process of MOTD stents. We subsequently compared Autostent to a previously described method that utilized non-automated computer-aided design. Three users designed stents for four patients with HNC enrolled in a prospective observational study. These patients were selected based on their varying dental anatomies, and each user repeatedly designed an MOTD stent for each patient three times, employing both the non-automated and semi-automated methods. Both methods were compared in terms of design time and stent volume.

Results: Semi-automation reduced the average design time by 23.6 min (51.2%, p = 0.001), regardless of user, dental anatomy, or trial number. Additionally, semi-automation decreased the average stent volume by 4.33 mL (12.9%, p = 0.016, univariate analysis). Although this reduction was not statistically significant when considering other experimental variables (p = 0.40, multivariate analysis), semi-automation did lower the variability in stent volume among users (the overall standard error of the mean decreased by 40%).

Conclusion: Our semi-automated workflow for designing and fabricating customized, 3D-printed MOTD stents significantly improves efficiency and reduces variability in the design. While these results indicate greater consistency compared to manual methods, further development is warranted to achieve full automation and to optimize clinical integration.

Background: Recurrent cervical cancer remains a therapeutic challenge despite advances in primary treatment. The emerging paradigm of oligorecurrence and oligometastasis has opened avenues for curative-intent local therapies, including re-irradiation. Modern radiotherapy techniques have enabled high-dose delivery with acceptable toxicity. This study aims to assess clinical outcomes and treatment-related toxicities in patients with oligorecurrent or oligometastatic cervical cancer treated with modern re-irradiation techniques.

Methods: This retrospective study included 20 cervical cancer patients with oligorecurrence or synchronous/metachronous oligometastases (≤ 5 lesions) who underwent at least one course of re-irradiation. Survival outcomes including locoregional recurrence-free survival (LRRFS), distant metastasis-free survival (DMFS), progression-free survival (PFS), and overall survival (OS) were estimated using Kaplan-Meier analysis. Genitourinary (GU), gastrointestinal (GI), and hematologic toxicities were assessed and graded based on CTCAE version 5.0.

Results: The median age was 53 years (range: 33-70), with 75% initially diagnosed at FIGO 2018 stage III. The predominant histologies were squamous cell carcinoma (50%) and adenocarcinoma (45%). Recurrences most commonly involved pelvic (30%) and para-aortic (30%) lymph nodes, with 50% occurring in-field. Stereotactic body radiotherapy (SBRT), volumetric modulated arc therapy (VMAT), and MR-guided adaptive brachytherapy (MR-GABT) were the most commonly used re-irradiation modalities, employed in 95% of patients. Median times to first and second recurrence were 11.1 months (IQR: 6.0-17.3) and 13.7 months (IQR: 5.6-21.7), respectively. At a median follow-up of 33.6 months, PFS, LRRFS, DMFS, and OS rates after the first recurrence were were 31.8%, 33.6%, 60.5%, and 84.2% respectively. Grade ≥ 2 genitourinary (GU), gastrointestinal (GI), and hematologic toxicities were observed in 40%, 25%, and 55% of patients, respectively. Grade 3 hematologic toxiciy was 25% and mostly occurred during chemotherapy administration. No grade ≥ 3 GU or GI toxicities were reported. The mean accumulated D0.03 cc after re-irradiation to bladder, rectum, sigmoid and bowel for in-fied/out-of-field were 83.8 ± 6.7/78.5 ± 7.5), 71.2 ± 3.9/69.5 ± 5.2, 68.0 ± 5.5/61.0 ± 5.3, and 62.9 ± 4.6/62.4 ± 7.1 GyEQD2₍₃₎, respectively.

Conclusion: Re-irradiation with contemporary radiotherapy techniques appears to be a feasible and effective salvage option for selected patients with limited recurrent or metastatic cervical cancer, yielding favorable survival and acceptable toxicity profiles.

Objective: This study evaluated the 8th edition American Joint Committee on Cancer (AJCC) staging system for esophageal squamous cell carcinoma (ESCC) and developed an improved staging framework using automated recursive partitioning analysis (autoRPA).

Methods: This retrospective study included 2773 ESCC patients treated with definitive intensity-modulated radiation therapy (IMRT) or chemo-IMRT across 8 Chinese centers (2001-2019). Kaplan‒Meier curves and log-rank tests were used to assess overall survival (OS). AutoRPA-derived stage groupings were optimized via the revised T/N criteria. The proposed staging was compared with the 8th edition AJCC staging via hazard discrimination, consistency, sample balance, and predictive accuracy.

Results: The 3-year, and 5-year rates for the entire cohort were 43.5%, and 34.0%, respectively. The AJCC T4a/T4b stages exhibited overlapping OS curves, prompting their consolidation into a single T4 stage. While the AJCC N2 and N3 stages showed overlapping OS curves, supraclavicular lymph node (SLN) metastasis independently predicted worse OS than N2, with outcomes similar to those of N3. Location-based SLN classification further refined nodal staging, with cervical esophageal-SLN metastasis classified as N1, upper thoracic-SLN metastasis as N2, and middle or lower thoracic-SLN metastasis as N3, yielding distinct OS stratification. The autoRPA-derived staging outperformed the 8th edition AJCC staging in hazard consistency, sample balance, and predictive accuracy, with RPA-I exhibiting distinctly sharper OS curves than other stages.

Conclusion: Combining T4a/T4b and SLN subclassification enhanced prognostic precision in ESCC, with the autoRPA staging demonstrating superior hazard consistency, sample balance, and predictive accuracy compared to the 8th edition AJCC staging, thereby guiding therapeutic strategies.

Purpose: Spiral volumetric modulated arc therapy (SVMAT) is an integrated radiation therapy technique with longitudinal couch movement to generate a spiral/helical trajectory. This approach combines the merits of volumetric modulated arc therapy (VMAT) and helical tomotherapy (HT). This study aimed to investigate the treatment planning of SVMAT for whole-brain radiotherapy (WBRT) with simultaneous integrated boost (SIB) for a large number (> 40) of metastases.

Materials and methods: Ten patients with multiple brain metastases (40-120 metastases) were retrospectively enrolled. These patients had previously received treatment with HT using the WBRT + SIB technique. Prescribed doses of 40 Gy for the whole brain and 60 Gy for the metastases were delivered in 20 fractions. In this study, SVMAT plans were designed using DeepPlan (version 1.3, Wisdom Tech., Hefei, Anhui, China) as the treatment planning system for the radiotherapy machine NeuRT Aurora (Neusoft IntelliRay Technology, Shenyang, Liaoning, China). In all SVMAT plans, the patient couch was set to move out after specified multiple gantry rotations and then move in within a single treatment fraction. The number of gantry rotations ranged between 6 and 16. These SVMAT plans were compared with HT and piecewise VMAT (previously proposed PVMAT) based on a plan quality metric (PQM) comprising 20 metrics.

Results: For target coverage and conformity index (CI) of whole brain and metastases, no significant differences were observed between the SVMAT&HT or between SVMAT&PVMAT plans (p > 0.05). The sparing of right hippocampus, optic nerves and optic chiasm were improved using the SVMAT plan compared to the HT plan (p < 0.05). However, no significant difference was observed between the SVMAT and PVMAT plans for OAR sparing (p > 0.05). The mean total scores of PQM were 51.70 ± 8.14 (mean ± standard deviation), 53.24 ± 5.84, 53.64 ± 7.16, 54.24 ± 7.06, 54.60 ± 6.30, and 55.05 ± 6.18 points for SVMAT plans with gantry rotations of 6 8, 10, 12, 14, and 16, respectively. The average score for HT was 38.18 ± 5.48 points, which was significantly lower than that for the SVMAT plans (p < 0.05). Furthermore, the mean score for PVMAT was 54.34 ± 6.48 points, and no significant differences were observed between SVMAT and PVMAT (p > 0.05). The beam delivery time was shorter for SVMAT with 6 (271.5 ± 53.7 s), 8(310.3 ± 42.9 s), and 10(359.6 ± 34.4 s) rotations compared to HT (393.0 ± 25.0 s) (p < 0.05) and also shorter for SVMAT with six rotations compared to PVMAT (312.6 ± 53.7 s) (p < 0.05).

Conclusions: For WBRT + SIB, SVMAT achieved improved plan quality and higher delivery efficiency compared with HT and had similar plan quality compared with PVMAT.