Radiation Oncology最新文献

Background: Neoadjuvant (preoperative) radiochemotherapy (nRCT) is a standard of care in locally advanced rectal cancer (LARC). Several studies have shown that the decline in ¹⁸FDG uptake after 2 weeks of nRCT compared with the baseline, i.e. the tumor's metabolic response, may correlate with histopathological response. However, our previous prospective study suggested that the tumor's histopathological response could be predicted by the metabolic response already observed after 1 week of nRCT. The current study was undertaken to validate these findings.

Methods: Thirty-eight patients with LARC who received standard nRCT followed by radical surgery were enrolled. Metabolic response, evaluated by the percent of change in maximum standardized uptake value (ΔSUVmax%), measured by PET-CT imaging at baseline and on day 8 of nRCT, was compared with the histopathological response at surgery. Histopathological response was assessed by pathological complete response (pCR) and, when possible, by tumor regression grade (TRG). We also examined the association of baseline and second PET-CT parameters with pCR and TRG at surgery.

Trial registration: 0239-07-RMC, registration date: 21/08/2007.

Results: Neither pCR nor TRG were associated with any change in PET-CT parameters after 1 week of treatment. Baseline metabolic tumor volume (MTV) was the only PET-CT parameter with a statistically significant association with pCR (p = 0.002), but not with TRG (p = 0.08).

Conclusions: A decrease in SUVmax after 1 week of nRCT for LARC failed to predict the achievement of pCR or TRG in the post-nRCT surgical specimen, underlining the importance of validation clinical trials. Nonetheless, our findings on the correlation between baseline MTV and histopathological response can, if confirmed, be a useful tool for treatment selection. Validation in a larger independent cohort is planned.

Background: Patients with brain metastases face a poor prognosis when deemed not to be suitable for onco-surgical intervention. This feasibility study analyses the outcome of adaptive radiosurgery applied in customised settings to a group of patients with brain metastases, where no other form of treatment was deemed safe and/or feasible.

Methods: 29 patients with 35 brain metastases deemed not to be candidates for surgery, radiotherapy or systemic treatment were treated with MRI-guided adaptive Gamma Knife radiosurgery in 3 separate sessions with a 72-hour interval. Customised synchronous double-dose prescriptions were systematically utilised at each session. Estimated survival at pre-treatment was fewer than 4 weeks due to the targeted intracranial lesions. A retrospective analysis was conducted on the whole cohort, with particular emphasis on those surviving 12 months and beyond.

Results: The median overall survival was 7.3 months, with a follow-up of 7.5 years. Survival at 6, 12, 24, 36, 48 and 60 months was 62%, 41%, 17%, 14%, 10% and 7%, respectively. Local tumour control (LTC) at 1 year was 75%. 4 patients developed local recurrence late on follow-up, with a survival ranging between 12 and 40 months. 2 patients were alive at the time of submission (115- and 117-months post-treatment) with no sequelae; the remainder succumbed to general disease progression, with neurologic death being avoided throughout the whole cohort. Adverse radiation effects (ARE) were reported in 5 patients, of which 4 remained asymptomatic throughout follow-up.

Conclusions: Based on the results of this first retrospective study, adaptive radiosurgery in double-dose prescription settings provided acceptable rates of LTC and ARE despite the underlying accelerated timeline, ultimately preventing neurologic death in a group of patients with an extremely poor prognosis. Prospective studies involving a larger number of patients with homogenous histology are warranted to validate the results of this study and optimise the technique.

Background: Proprietary bi-nuclide plaques combine the radiation properties of beta and gamma brachytherapy and can irradiate a larger target volume compared to ruthenium-plaques. While reducing the dose to structures outside the target volume, brachytherapy with bi-nuclide-plaques (BBNP) delivers a higher target dose compared to iodine-plaques. We aimed at analyzing the local tumor control and eye retention probability after BBNP.

Methods: All consecutive cases with large uveal melanoma (tumor thickness ≥ 7 mm) treated with BBNP at our institution between 01/1999 and 12/2020 were included (n = 576, median follow-up: 30.8 months [interquartile range, IQR: 12.9-57.4]). Univariable and multivariable Cox regression analyses were performed.

Results: Secondary enucleation (SE) was performed in 13.5% of cases (n = 78) after the median of 20.0 months (IQR: 9.0-34.7) post-BBNP. The overall rate of local tumor recurrence (LR) in the cohort was 8.5% (n = 49) and was diagnosed at the median post-BBNP interval of 20.0 months (IQR: 15.6-35.2). Of the patients' baseline characteristics, higher age (> 67 years, adjusted hazard ratio [aHR] = 1.80, p = 0.011), tumor thickness (> 8.5 mm, aHR = 2.20, p = 0.002), visual acuity (> 0.5 logMAR, aHR = 1.83, p = 0.009), and sclera dose (> 1000 Gy, aHR = 1.65, p = 0.034) were independently associated with the risk of SE. In turn, higher age (> 67 years, aHR = 1.93, p = 0.023), tumor thickness (> 8.5 mm, aHR = 2.02, p = 0.020), and visual acuity (> 0.5 logMAR, aHR = 2.27, p = 0.005) were independently related to LR.

Conclusions: BBNP facilitates eye retention in 86.5% of patients with large uveal melanoma 2.5 years after treatment. Patients' baseline, tumor and treatment characteristics were strongly associated with the risk of SE and LR after BBNP.

Background: This study aimed to develop and validate a multi-temporal magnetic resonance imaging (MRI)-based delta-radiomics model to accurately predict severe acute radiation enteritis risk in patients undergoing total neoadjuvant therapy (TNT) for locally advanced rectal cancer (LARC).

Methods: A retrospective analysis was conducted on the data from 92 patients with LARC who received TNT. All patients underwent pelvic MRI at baseline (pre-treatment) and after neoadjuvant radiotherapy (post-RT). Radiomic features of the primary tumor region were extracted from T2-weighted images at both timepoints. Four delta feature strategies were defined (absolute difference, percent change, ratio, and feature fusion) by concatenating pre- and post-RT features. Severe acute radiation enteritis (SARE) was defined as a composite CTCAE-based symptom score of ≥ 3 within the first 2 weeks of radiotherapy. Features were selected via statistical evaluation and least absolute shrinkage and selection operator regression. Support vector machine (SVM) classifiers were trained using baseline, post-RT, delta, and combined radiomic and clinical features. Model performance was evaluated in an independent test set based on the area under the curve (AUC) value and other metrics.

Results: Only the delta-fusion strategy retained stable radiomic features after selection, and outperformed the difference, percent, and ratio definitions in terms of feature stability and model performance. The SVM model, based on combined delta-fusion radiomics and clinical variables, demonstrated the best predictive performance and generalizability. In the independent test cohort, this combined model demonstrated an AUC value of 0.711, sensitivity of 88.9%, and F1-score of 0.696; these values surpassed those of models built with baseline-only or delta difference features.

Conclusions: Integrating multi-temporal radiomic features via delta-fusion with clinical factors markedly improved early prediction of SARE in LARC. The delta-fusion approach outperformed conventional delta calculations, and demonstrated superior predictive performance. This highlights its potential in guiding individualized TNT sequencing and proactive toxicity management.

Clinical registration number: NA.

Objectives: This study aimed to quantify dynamic changes in the Apparent Diffusion Coefficient (ADC) values of the parotid glands during radiotherapy and explore their correlation with early-stage gland dysfunction.

Methods: Nasopharyngeal carcinoma patients receiving definitive chemoradiotherapy were prospectively enrolled. Magnetic Resonance Diffusion-Weighted Imaging (MR-DWI) was performed at pre-radiotherapy (pre-RT), the 5th, 15th fractions, and end of radiotherapy. ADC values and volumes for ipsilateral (IP) and contralateral parotid glands (CP) were recorded. Salivary function was assessed using scintigraphy (SGS) and the Radiation Therapy Oncology Group (RTOG) xerostomia criteria.

Results: A total of 80 eligible patients were analyzed. From pre-radiotherapy(pre-RT) to the end of radiotherapy, Pearson correlation analysis showed that changes in ADC values were positively correlated with the delivered dose (p < 0.01) and reduction in parotid volume (p < 0.01).From pre-RT to the 5th fraction, mean ADC values((ΔADC5) increased significantly by 17.7% (IP) and 16.3% (CP) (p < 0.01), with minimal volume changes(ΔrV5) (p = 0.060, p = 0.068). Spearman analysis revealed a positive association between the change in ΔADC5 and the incidence of xerostomia 6 months after radiotherapy (p < 0.01). Multivariable analysis identified ΔADC5 rather than ΔrV5 as an independent predictor of secretory dysfunction (IP: Odds Ratio (OR) = 1.010, p = 0.015 by SGS; OR = 1.026, p = 0.000 by RTOG; CP: OR = 1.017, p = 0.004 by SGS; OR = 1.015, p = 0.002 by RTOG).

Conclusion: This study analyze the dynamic changes in parotid gland ADC values, volume, and secretion function throughout radiotherapy. Changes in ΔADC5 can predict radiation-induced parotid gland injury before significant volume changes occur, thereby enabling early intervention.

Aims: Recent advances in Radiotherapy have led to the development of online adaptive RT (oART), a procedure addressing inter-fraction anatomical variations. Integrating artificial intelligence (AI) into the oART procedure speeds up the process and reduces user dependency. This study investigates the dosimetric advantage of implementing AI-driven oART in prostate cancer.

Methods: A total of 31 prostate cancer patients treated with oART on an AI-integrated Linac were analyzed. Patients were categorized by nodal involvement. For prostate-only cases, the Clinical Target Volume (CTV) included the prostate and seminal vesicles (CTV1), with a 5 mm margin (8 mm caudally) for Planning Target Volume (PTV), named PTV1. For nodal cases, pelvic lymph nodes were added (and categorized as CTV2) with a 5 mm isotropic margin (PTV2). Daily CBCTs were acquired, with OARs (rectum, bladder, bowels) automatically segmented by the AI system, while targets were manually delineated. Two plans were generated: a predicted one, calculating the original plan's fluence on daily anatomy, and an adapted one, with complete fluence re-optimization. Daily DVH indicators for PTV(V95%), CTV(D98%), bladder (V65Gy), bowel (V45Gy), and rectum (V50Gy) were compared between predicted and adapted plans using the Wilcoxon-Mann-Whitney test. Total session time, from CBCT acquisition to treatment completion, was also recorded.

Results: oART treatment improved prostate coverage in both patient groups (+10.4% and +11.8% in PTV V95% for patients with and without lymph nodes) and CTV D98% (+2.6% with lymph nodes, +2.9% without). Improvements for arm 2 were smaller (+3.1% in PTV2 V95%, +2.2% in CTV2 D98%). Statistical differences were insignificant in OAR DVH indicators (p > 0.1). Median treatment time was 25 min and 32 min for prostate-only and lymph node cases, respectively.

Conclusion: This study demonstrates that oART in prostate cancer results in a significant improvement in target coverage with no significant difference in OARs.

Background: Comorbid mental health symptoms impact 30-40% of cancer patients, significantly compromising treatment adherence and increasing mortality rates. Among patients undergoing radiation therapy, which is delivered with palliative intent in nearly half of all cases and for those nearing end-of-life, these rates may be even higher. Emerging research underscores the promising potential of psychedelic-assisted therapy (PAT) in alleviating cancer-related psychological distress. However, the perspectives of cancer patients on the therapeutic utility of psychedelics remain unexplored.

Methods and materials: Adult patients with a cancer diagnosis were recruited in Radiation Oncology Clinic between May 2023 and August 2024. They included patients being evaluated before, during, or after radiation therapy. Data on demographics, medical history, prior psychedelic use, and measures of mental health burden and quality of life using validated questionnaires were collected to assess interest in PAT and factors associated with such interest.

Results: 100 patients enrolled in the study. 43% expressed interest in PAT, while 31% were opposed, and 26% were unsure. Prior diagnoses of mental health disorders like anxiety and depression, prior recreational psychedelic use, younger age, and male sex were positively associated with interest in PAT. Notably, patients with higher levels of depression, worse spiritual well-being, worse demoralization, worse quality of life, and more pain, symptoms that are targeted with PAT, were more likely to be receptive to it. Hesitancy was primarily attributed to a lack of information, cited by 43% of those not interested or unsure.

Conclusion: Psychedelic-assisted therapy represents a promising avenue to address critical gaps in cancer-related mental health care, and this study suggests that a substantial portion of cancer patients are receptive to and curious about this approach. The primary barrier to acceptance is informational, emphasizing the need for further research and education to dispel misconceptions and increase awareness of the safety and efficacy of psychedelic therapies. Future work should explore provider perspectives, patient outcomes, and the integration of PAT into palliative care frameworks.

Background: Anatomical variations that occur during radiation therapy in head and neck cancer (HNC) patients can lead to significant dosimetric changes. The purpose of this study is to evaluate dosimetric and volume changes in key anatomical structures for different treatment sites in HNC patients, and to determine the percentage of patients who need adaptive radiotherapy (ART) per treatment site.

Methods: A total of 1,740 megavoltage computed tomography (MVCT) images from 58 HNC patients treated with helical tomotherapy (HT) were exported to the PreciseART™ (Accuray) software. Volume changes in the planning target volume (PTV) and the organs at risk (OARs) in the planning stage and the first and last fractions of treatment were calculated. The differences between the values of actual accumulated and initial plan doses were used to determine which patients benefit ART.

Results: The average volume changes between the planning stage and the first fraction were 3.93%, 4.49%, and 6.46% for the PTV, brainstem, and spinal cord, respectively, for all patients. However, the average volume changes between the first and last fractions of treatment were relatively small and included 0.84%, 3.62%, and 1.19% for the PTV, brainstem, and spinal cord, respectively. The average dose changes between the initial planned dose and the actual cumulative dose in the last fraction were in the range of 10.43-30.81%; 4.66-11.61%; 3.73-9.97%; and - 0.17-5.40% for the brainstem, left parotid, right parotid, and spinal cord, respectively, for all patients. A maximum of 10.53%, 28.57%, and 18.18% of patients with oral cavity, larynx, and nasopharyngeal cancers, respectively, needed ART. Patients with salivary gland cancers did not need ART.

Conclusion: Although monitoring the volume and dose changes of the tumor and OARs during the course of radiation therapy is important, not all patients need ART. Criteria such as weight loss and rapid tumor shrinkage should be considered when selecting candidate patients for ART. The time interval between CT simulation and the first fraction also plays an important role in the difference in the volume and dose to organs during the course of radiation therapy.

Background: Lung cancer primarily affects elderly individuals and is the leading cause of cancer-related death in people aged 80 years and older. In addition, the incidence of multiple primary lung cancer (MPLC) is increasing worldwide. Although surgery is recommended as the standard of care, many elderly patients are considered medically unsuitable, or they refuse surgery. The role of stereotactic body radiotherapy (SBRT) as an alternative treatment option for these elderly patients, particularly those with multiple primary lung cancer, has not been fully elucidated. Therefore, the aim of this study was to report the outcome and toxicities associated with SBRT for histologically confirmed early-stage non-small cell lung cancer (NSCLC) and synchronous and metachronous multiple primary lung cancer in patients aged ≥ 80 years.

Methods: This retrospective study included 118 patients aged ≥ 80 years with a total of 141 SBRT-treated primary lung cancers (19 patients with MPLC). We assessed local control (LC), progression-free survival (PFS), overall survival (OS) and cancer-specific survival (CSS). We further evaluated toxicities and factors impacting therapeutic efficacy.

Results: The median follow-up after SBRT was 47 months (range 3-169 months). The LC rate was 96.2% (95% CI: 90.1 to 98.6%) two years and 86.4% (71.8 to 93.8%) five years after SBRT for NSCLC/MPLC. The PFS and OS rates were 67.0% (57.4 to - 74.9%) and 74.7% (65.4 to - 81.1%), respectively, after two years and 24.7% (14.5 to 35.6%) and 30.2% (19.4 to 41.7%), respectively, after five years. The CSS rate was 88.6% (80.3-93.6%) at two years and 76.6% (61.4-86.4%) at 5 years after SBRT. Age and the Charlson Comorbidity Index score were found to be independent predictors of OS and PFS. Predictors other than these patient-related factors could not be identified. Toxicities higher than Grade 2 after SBRT of NSCLC and MPLC were not observed.

Conclusion: This study emphasises the efficacy and safety of SBRT in the treatment of early-stage NSCLC in patients aged ≥ 80 years, including those with MPLC. SBRT proves to be an appropriate treatment modality for this frail patient group, as it provides favourable LC and CSS rates with low toxicity.

Purpose: To assess the effect of treatment time and waiting time on clinical outcome for patients with esophageal squamous cell carcinoma (ESCC) treated with definitive concurrent chemoradiotherapy (CCRT).

Methods and materials: A retrospective analysis was conducted on ESCC patients treated with definitive CCRT between 2008 and 2024 at Xijing hospital. Analyses were performed according to the following separate definitions of treatment time and waiting time: (1) theoretical minimal radiotherapy time (TMRT); (2) overall treatment time (OTT); (3) exceeding time (ET); (4) time to start of radiotherapy (TSR); (5) overall waiting time (OWT). Associations between treatment time and waiting time and survival outcome were investigated using Cox regression analyses.

Results: A total of 541 patients were studied and prolonged treatment time and waiting time were common. Overall, the median TMRT, OTT, ET, TSR, and OWT were 38 days [interquartile range (IQR): 38-40 days], 43 days (IQR: 40-47 days), 4 days (IQR: 2-7 days), 88 days (IQR: 62-126 days), and 21 days (IQR: 14-31 days), respectively. Multivariate analysis revealed that delay of treatment time and waiting time has no effect on overall survival (OS), locoregional relapse-free survival (LRFS), distant metastasis-free survival (DMFS), and progression-free survival (PFS) (all p > 0.05). In the subgroup of patients with T1-2 ESCC disease, the TSR < 72 days group had significantly more favorable OS (p = 0.009), LRFS (p = 0.003), and PFS (p = 0.022) compared with TSR ≥ 72 days group.

Conclusions: Delay of treatment time and waiting time has no effect on OS, LRFS, DMFS, and PFS. However, longer TSR was found to be associated with diminished survival outcomes for T1-2 stage rather than T3-4 ESCC patients treated with definitive CCRT.