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.