Radiation Oncology最新文献

Background: Chemo-reirradiation has emerged as a feasible neoadjuvant therapy to improve resectability in locally recurrent rectal cancer (LRRC). However, its combination with surgery and intraoperative electron radiotherapy (IOERT) raises concerns regarding cumulative toxicity. This retrospective study aimed to evaluate acute and late toxicity profiles, local control and survival outcomes, following this multimodal approach in our institution.

Methods: LRRC patients who underwent chemo-reirradiation and surgery with IOERT (median cumulative tumour dose of 113 Gy, α/β = 10 Gy) between September 2021 to December 2024 were retrospectively analysed. Acute and late treatment-related toxicities (CTCAE) were recorded in a prospectively maintained database. Secondary outcomes were overall survival (OS) and local re-recurrence-free survival (LRFS).

Results: Among 40 patients, no grade 4 or 5 toxicities were observed. Acute cumulative treatment-related grade 3 toxicities occurred in 14/37 (38%) patients, predominantly consisting of erectile dysfunction (5/37, 14%), abscess formation (4/37, 11%) or peripheral neuropathy (2/37, 5%). Late grade 3 toxicities occurred in 13/30 (43%) patients, comprising mainly of erectile dysfunction (5/30, 17%), renal disorders (5/30, 17%) or peripheral neuropathy (2/30, 7%). After a median follow-up period of 21 months (IQR 12-32) after surgery, 2-year overall survival (OS) and local re-recurrence-free survival (LRFS) were 75.7% and 37.2%, respectively.

Conclusion: In previously irradiated LRRC patients, a multimodality approach combining chemo-reirradiation and extensive surgery with IOERT demonstrated acceptable treatment-related toxicities and favourable oncological outcomes for this high-risk population. Further research with longer follow-up is warranted to identify risk factors associated with treatment-related toxicity.

Background and purpose: This study aimed to evaluate whether the clinical prototype of intraoperative electron FLASH radiotherapy (CPIO-EFLASH), with a source-surface distance (SSD) of 50 cm, could achieve ultra-high dose rates, effectively control tumors, and trigger the FLASH tissue-sparing effect in preclinical models.

Materials and methods: Subcutaneous tumor-bearing mice (4T1 breast cancer, U87-MG glioma, PAN02 pancreatic cancer) and healthy C57BL/6 female mice (whole-brain, thorax, abdomen and single-leg irradiation) were subjected with ultra-high dose rate radiotherapy (UHDR-RT, ≥ 40 Gy/s), conventional doserate radiotherapy (CONV-RT,0.07 Gy/s), or sham radiotherapy (Control). We evaluated survival status, tumor growth suppression, apoptosis, proliferation, and DNA damage in tumor tissues, along with radiation-induced injuries to the brain, lung, intestine, and skin tissues.

Results: The actual dose rates of UHDR-RT ranged from 192 to 473 Gy/s. No significant difference in tumor growth suppression was observed between the UHDR-RT and CONV-RT. Two months post whole-brain irradiation, UHDR-RT demonstrated better spatial learning and memory abilities compared to CONV-RT. At 120 days post whole-thorax irradiation and 90 days post whole-abdomen irradiation, the survival rates of UHDR-RT were also significantly higher. Histological analyses revealed more severe injury to lung and intestinal tissues in the CONV-RT group. Additionally, UHDR-RT exhibited milder radiation-induced skin injury from 2 to 8 weeks post-irradiation.

Conclusion: The CPIO-EFLASH can achieve ultra-high dose rates (≥ 40 Gy/s at an SSD of 50 cm) and trigger significant normal tissue-sparing effects. Integrating electronic FLASH technology into intraoperative radiotherapy may bring potential clinical benefits by effectively treating tumors, while minimizing radiation-induced injury to normal tissues. Our findings highlight the necessity for further clinical trials of CPIO-EFLASH in intraoperative radiotherapy.

Background: Lymphorrhea is a complication that can arise after vascular, abdominal or pelvic interventions and is associated with significant morbidity. While conservative management is typically effective, some cases remain refractory.

Methods: This retrospective cross-sectional study analyzed 43 patients with persistent inguinal lymphorrhea treated at a tertiary hospital between 2008 and 2018. All patients received external beam radiotherapy (EBRT) using 3D conformal techniques with photons (6-18 MV). The delivered dose was 7.5 Gy in five 1,5 Gy/fractions.

Results: Complete closure of the lymphatic fistula was achieved in all patients. Three required reirradiation with the same schedule to reach complete resolution. No acute or late toxicity was observed in any case.

Conclusions: Low-dose EBRT is a safe and effective treatment option for persistent lymphorrhea refractory to conservative measures. Its anti-inflammatory and fibrosing effects support its therapeutic use in benign lymphatic complications.

Trial registration: Not applicable.

Purpose: To develop and validate a Knowledge-Based Planning (KBP) model for prostate stereotactic body radiation therapy (SBRT) using a comprehensive dosimetric scorecard, aiming to improve plan quality and consistency while meeting the stringent criteria of the Adaptive Radiation Therapy Individualized Approach - Prostate (ARTIA) trial.

Methods: A KBP model (ProstateSBRT-ARTIA-SIB40-36 Gy v1.1) was developed using RapidPlan v15.6 with 41 carefully selected prostate SBRT cases. A 35-metric dosimetric scorecard was created to guide the model development and evaluation process. The model was trained iteratively, with the scorecard used to tune optimization objectives and priorities. 10 independent cases were used for validation, testing both VMAT and IMRT beam arrangements.

Results: The KBP model demonstrated significant improvement in plan quality compared to original clinical plans, with the average scorecard score increasing from 166.2/229 to 197.4/229 points. Validation cases showed consistent high-quality plan generation for both VMAT and IMRT techniques. The model exhibited flexibility in adapting to various dose levels and clinical scenarios, including the ability to scale urethral dose constraints.

Conclusion: The dosimetric scorecard-guided KBP model for prostate SBRT demonstrates the potential to generate high-quality treatment plans efficiently and consistently. This approach offers a powerful method for translating complex clinical intent into actionable planning objectives, potentially improving treatment quality and reducing inter-planner variability. Future work will focus on expanding the model's capabilities, including boosting gross disease volumes and exploring direct optimization based on comprehensive dosimetric scorecards.

The role of hyperthermia (HT) in conventional oncological treatment has been a subject of research for decades; however, HT has not been incorporated into treatment guidelines on a universal basis. Preclinical studies have demonstrated the mechanism of action of HT and have indicated a clear effect that can enhance the effects of radiotherapy (RT), chemotherapy, or immunotherapy. The underlying mechanism of HTs action involves either the enhancement of the immune system response or the interference with crucial cellular pathways that are aberrantly altered during the neoplastic process. Consequently, HT has the potential to augment the efficacy of RT treatments markedly. Randomized clinical trials have further demonstrated the efficacy and safety of combining RT and HT. However, it is important to note that the majority of these observations were derived from studies conducted up to two decades ago, which may not fully reflect the current standard of care. The present focus is on the combination of these treatment techniques with modern systemic treatment, which is based on immunotherapy and molecularly targeted drugs. Significant advancements have also been made in the field of HT delivery and the strategies for optimal use of HT. Therefore, it is imperative to synthesize the extant body of knowledge in this field to inform the advancement of techniques for integrating HT with radiation therapy.

Background: This systematic review and meta-analysis assessed the role of radiotherapy (RTx) in patients with unresectable or metastatic intrahepatic cholangiocarcinoma (ICC).

Methods: A systematic search of the MEDLINE, EMBASE, and Cochrane databases was conducted to identify relevant studies published before November 2024. Meta-analyses were performed to assess the median overall survival (OS), 1- and 2-year OS rates, and local control (LC) rates in patients with unresectable or metastatic ICC treated with RTx. For studies reporting hazard ratios (HR), OS was compared between patients receiving chemotherapy (CTx) with RTx versus CTx alone and between dose-escalated and conventional-dose RTx. The toxicity outcomes of the included studies were systematically reviewed.

Results: Nine articles (n = 1,792) were included in the analysis. Pooled analysis revealed a median OS of 15.59 months, with 1-year and 2-year OS rates of 69% and 38%, respectively. The one- and 2-year LC rates were 79% and 55%, respectively. Four studies comparing CTx with RTx versus CTx alone revealed that the combination group had significantly improved OS (HR, 0.67). Additionally, dose-escalated RTx was associated with better OS than conventional-dose RTx (HR, 0.53). Grade ≥ 3 gastrointestinal toxicity occurred in 3.7% of patients, and grade 5 toxicity was rare (0.3%).

Conclusions: RTx, particularly with dose escalation or in combination with CTx, may provide survival benefits with acceptable toxicity, supporting further prospective evaluations of unresectable or metastatic ICC.

Introduction: Vestibular schwannoma (VS) often shows transient post-radiosurgery swelling ("pseudoprogression," PP) that mimics true progression (TP). We validated volumetric rules to separate PP from TP and linked growth patterns to clinical outcome.

Method: We retrospectively reviewed 259 sporadic VS cases treated with single-fraction stereotactic radiosurgery (2012-2024). SRS was delivered with a median margin dose of 12 Gy, prescribed to the institutional peripheral isodose line, using a median of 5 isocentres. Tumours were manually segmented on serial MRIs ≥ 24 months. PP was defined as > 20% volume rise ≤ 12 months followed by ≥ 10% fall ≤ 24 months; TP as > 15% rise > 36 months with persistent growth. Two alternative thresholds (> 25% rise any time; >10% rise > 24 months without regression) were tested. Longitudinal trajectories were clustered with Gaussian-mixture models. Outcomes included hearing, facial and trigeminal function, and Dizziness Handicap Index (DHI).

Results: Four growth clusters emerged: early PP (35.5%), late PP (11.2%), stable (41.3%) and TP (12%). The PP rule yielded 86% sensitivity and 93% specificity (AUC 0.92); the TP rule 77%/95% (AUC 0.90). Alternative thresholds performed worse (AUC 0.81-0.85). Serviceable hearing was preserved in ≥ 86% of PP or stable tumours but only 61% in TP (p < 0.01).

Conclusion: Time-anchored volumetric rules accurately distinguish transient post-SRS swelling from genuine progression. Incorporating these criteria into routine surveillance can prevent premature salvage therapy while ensuring timely intervention for the minority of tumours that truly grow.

Cardiotoxicity following thoracic radiotherapy remains a critical issue, and this study aimed to assess the risk of Cardiovascular-Related Death (CVRD) after thoracic radiotherapy while comparing the risk of CVRD at different cancer sites. Data on patients with thoracic cancers treated with radiotherapy between 2000 and 2020 were analyzed, and the risk of CVRD was evaluated using death rates, Fine-Gray competing risks model, standardized mortality ratio (SMR), absolute excess risk (AER), and Cox regression to develop a predictive model. Patients receiving radiotherapy for thoracic cancer had a significantly increased risk of CVRD compared with the general population (Overall AER = 28.59, SMR = 2.37, 95% CI: 2.33-2.40). The risk of CVRD after radiotherapy was significantly lower in the right chest than the left (HR = 0.84, 95% CI: 0.79-0.89) and significantly higher in the left lower lung than in the upper (HR = 1.11, 95% CI: 1.01-1.22). A predictive model for the risk of CVRD in patients with left lower lung after radiotherapy was further constructed (C-index = 0.67, 95% CI: 0.67-0.68). The findings highlight that thoracic radiotherapy significantly increases cardiovascular disease risk, with patients with left lower lung cancer exhibiting the highest CVRD risk. A robust predictive model was developed, offering valuable insights for managing and predicting CVRD risk in thoracic malignancies.