Radiation oncology journal最新文献

Purpose: For patients with unresectable extrahepatic cholangiocarcinoma, radiotherapy (RT) is the definitive treatment. In this study, we aimed to evaluate the role of two different RT techniques for definitive treatment of unresectable extrahepatic cholangiocarcinoma.

Materials and methods: Eighteen patients with unresectable extrahepatic cholangiocarcinoma treated with either conventionally fractionated radiotherapy (CFRT) or stereotactic body radiotherapy (SBRT) were evaluated retrospectively. Patients treated with CFRT also received elective nodal irradiation (ENI) in addition to the primary tumor.

Results: Median doses of CFRT and SBRT were 50.4 Gy (range, 45 to 59.4) in 25-33 fractions and 37.5 Gy (range, 27.5 to 50) in 3-5 fractions, respectively. Median follow-up was 22 months (range, 7 to 138). During follow-up, local failure occured in one patient (12.5%) in the SBRT group and six patients (60.0%) in the CFRT group (p = 0.041). On the other hand, regional failure occured in five patients (62.5%) in the SBRT group and in two patients (20.0%) in the CFRT group (p = 0.047). Two-year overall survival (OS), local-regional failure-free survival (LRFFS), and distant metastasis-free survival (DMFS) rates were 35%, 30%, and 24%, respectively. Younger age (≤55 years) was associated with better OS, LRFFS, and DMFS. None of the patients experienced ≥grade 3 acute or late toxicity.

Conclusion: While SBRT may provide better local tumor control compared to CFRT, the absence of ENI can result in increased regional recurrences. Hence, conducting prospective studies to examine the safety and efficacy of integrating hypofractionated ENI into SBRT is warranted.

Purpose: This study aims to evaluate the efficacy of radiotherapy (RT) in patients with steroid-resistant thyroid eye disease (TED) by assessing clinical outcomes in orbital inflammation and exophthalmos.

Materials and methods: Sixty-two patients with confirmed TED and resistance to intravenous steroid therapy were treated with RT. Most patients received intravenous methylprednisolone (500 mg weekly for 6 weeks, followed by 250 mg weekly for 6 weeks). After steroid treatment, patients underwent RT with a total dose of 20 Gy delivered in 10 fractions. Clinical parameters were assessed at five time points: initial presentation, post-intravenous steroid therapy, and 1, 6, and 12 months after RT. Inflammation was evaluated using clinical activity score (CAS). Exophthalmos was quantified through posterior scleral distance (PSD) measurements on computed tomography imaging. Statistical analysis involved repeated measures analysis of variance and Cohen's d effect size calculations.

Results: CAS showed significant reduction from baseline (mean, 3.309) to 12 months post-RT (mean, 0.187), with the largest effect size observed between baseline and 12 months (Cohen's d = 10.88). PSD showed worsening after intravenous steroid therapy but gradually improved after RT, approaching baseline values at 12 months. Disease reactivation occurred in only two patients, and three required strabismus correction surgery. Minimal adverse events were reported during follow-up.

Conclusion: RT demonstrated significant efficacy in treating steroid-resistant TED, with sustained improvements in both orbital inflammation and exophthalmos. These findings suggest RT as a viable alternative for patients unresponsive to steroid therapy, offering meaningful long-term clinical benefits with minimal adverse effects.

This study evaluates the use of magnetic resonance-guided radiation therapy (MRgRT) as an alternative to brachytherapy in treating para-urethral gynecological cancers, particularly for patients who are not candidates for brachytherapy. Five female patients with advanced para-urethral gynecological cancers underwent MRgRT using a custom 3-dimensional-printed intravaginal cylinder for image registration and treatment alignment. MRgRT was administered as a five-fraction adaptive boost following standard chemoradiation, with each fraction utilizing the cylinder to achieve precise positioning and improve organ sparing. A 1.5T magnetic resonance linear accelerator was used to deliver adapt-to-shape treatment, allowing real-time adjustments to compensate for anatomical variations. The cylinder served not only as a surrogate for accurate image registration but also as a spacer to displace the rectum from high-dose regions. The median follow-up period was 14.4 months, during which all patients completed treatment with no grade >3 genitourinary toxicities. Acute toxicities included dysuria and vaginal pain, while chronic toxicities, such as urinary incontinence and mild cystitis, were recorded in a subset of patients. Treatment achieved an overall survival rate of 100% and a recurrence-free survival rate of 80%. Dosimetric analysis demonstrated effective target coverage with minimal exposure to surrounding organs, particularly sparing the urethra from hotspots, unlike traditional brachytherapy. These results suggest that MRgRT with a vaginal cylinder offers a promising approach for managing para-urethral gynecological cancers in patients ineligible for brachytherapy. Further studies are warranted to validate these findings and refine treatment protocols.

Purpose: No guidelines exist to delineate radiation therapy (RT) targets for the treatment of multiple glioblastoma (mGBM). This study analyzes margins around the gross tumor volume (GTV) to create a clinical target volume (CTV), comparing response parameters and modalities of recurrence. Material and Methods: One-hundred and three mGBM patients with a CTV margin of 2 cm (GTV + 2.0 cm) or 1 cm (GTV + 1.0 cm) were retrospectively analyzed. All patients received a total dose of 59.4-60 Gy in 1.8-2.0 Gy daily fractions, delivered from 4 to 8 weeks after surgery, concomitantly with temozolomide (75 mg/m2). Overall survival (OS) and progression-free survival (PFS) were calculated from the date of surgery until diagnosis of disease progression performed by magnetic resonance imaging and classified as marginal, in-field, or distant, comparing site of progression with dose distribution in RT plan.

Results: OS in mGBM CTV1 group was 11.2 months (95% confidence interval [CI], 10.3-12.1), and 9.2 months in mGBM CTV2 group (95% CI, 9.0-11.3). PFS in mGBM CTV1 group occurred within 8.3 months (95% CI, 7.3-9.3), and 7.3 months in mGBM CTV2 group (95% CI, 6.4-8.1). No difference was observed between the two groups in terms of OS and PFS time distribution. Adjusted to a multivariate Cox risk model, epidermal growth factor receptor amplification resulted a negative prognostic factor for both OS and PFS.

Conclusion: In mGBM, the use of a 1 cm CTV expansion seems feasible as it does not significantly affect oncological outcomes and progression outcome.

Purpose: Retroperitoneal sarcomas (RPS) are rare tumors that present unique challenges, often due to late presentation, and the proximity of critical organs makes complete surgical resection challenging. This study aimed to assess the feasibility of neoadjuvant short-course radiotherapy (SCRT) targeting margins-at-risk and to assess its potential impact on outcomes.

Materials and methods: This is a single-center, prospective, non-randomized feasibility study. SCRT was administered via image-guided volumetric modulated arc therapy, consisting of 5 fractions of daily radiotherapy followed by immediate surgery. As a starting dose, patients were prescribed 25 Gy in 5 fractions. For the escalation stage, patients were prescribed 30 Gy in 5 fractions. Only the presumed threatened surgical margins were delineated for large tumors.

Results: Patients with either primary or recurrent RPS were recruited. Eight patients underwent SCRT but one patient did not have a resection as planned. Seven patients underwent surgical resection, of whom one passed away 3 months postoperative from a cardiac event. After a median follow-up of 20.5 months for the six postoperative survivors, there were no overt long-term toxicities and one patient relapsed out-of-radiotherapy-field.

Conclusion: SCRT to RPS with a margin boost followed by immediate surgery is worth investigating. A starting dose of 30 Gy in 5 fractions is recommended for further studies. Longer-term follow-up is necessary.

Purpose: This study aimed to investigate changes in target coverage using magnetic resonance-guided online adaptive radiotherapy (MRgoART) for kidney tumors and to evaluate the suitable timing of treatment.

Materials and methods: Among patients treated with 3-fraction MRgoART for kidney cancer, 18 tumors located within 1 cm of the gastrointestinal tract were selected. Stereotactic radiosurgery planning with a prescription dose of 26 Gy was performed using pretreatment simulation and three MRgoART timings with an adapt-to-shape method. The best MRgoART plan was defined as the plan achieving the highest percentage of planning target volume (PTV) coverage of 26 Gy. In clinical scenario simulation, MRgoART plans were evaluated in the order of actual treatment. Waiting for the next timing was done when the PTV coverage of 26 Gy did not achieve 95%-99% or did not increase by 5% or more compared to the pretreatment plan.

Results: The median percentages of PTV receiving 26 Gy in pretreatment and the first, second, and third MRgoART were 82% (range, 19%), 63% (range, 7% to 99%), 88% (range, 31% to 99%), and 95% (range, 3% to 99%), respectively. Comparing pretreatment simulation plans with the best MRgoART plans showed a significant difference (p = 0.025). In the clinical scenario simulation, 16 of the 18 planning series, including nine plans with 95%-99% PTV coverage of 26 Gy and seven plans with increased PTV coverage by 5% or more, would be irradiated at a good timing.

Conclusion: MRgoART revealed dose coverage differences at each MRgoART timing. Waiting for optimal irradiation timing could be an option in case of suboptimal timing.

This study aimed to evaluate the long-term efficacy and complication of radiotherapy for benign soft tissue tumors. Five cases of benign soft tissue tumors (two plexiform neurofibromas, two juvenile nasopharyngeal angiofibromas, and one cavernous sinus hemangioma) who underwent radiotherapy were enrolled. All patients had at least 10 years of follow-up. The median follow-up duration was 12 years (range, 10 to 27). Three patients underwent incomplete excision prior to radiotherapy. Radiation doses were either 54 Gy in 30 fractions or 50.4 Gy in 28 fractions (1.8 Gy per fraction). Every patient achieved complete remission (CR) or near-CR. The tumor volume decreased significantly within the first 2 years of follow-up and continued to decrease slowly up to 10 years; no distinct further decrease in tumor volume was observed after 10 years. One patient developed left mandibular hypoplasia 8 years after radiotherapy. Significant volume decrease was achievable within a few years after radiotherapy in benign soft tissue tumors. Therefore, radiotherapy is a viable option for unresectable or incompletely resected benign soft tissue tumors with a minimum risk of complication.

Purpose: Implementing intensity-modulated brachytherapy (IMBT) techniques with high-energy sources like 60Co has always been challenging due to the clinical limitations of the applicator dimensions. This study aims to investigate using tungsten trioxide nanoparticles/epoxy composite as a shielding material to enhance the protective properties of a redesigned applicator.

Materials and methods: The Geant4 application to tomographic emission, the Geant4-based Monte Carlo dose calculation engine (version 9.0), was used to simulate the shielding composite and the IMBT technique with a voxelated patient-based phantom. To evaluate the effectiveness of the new shielding material, IMBT plans created with the redesigned applicator were compared with those with a conventional applicator. 60Co and 192Ir were utilized, and in the same high-risk clinical target volumes D90, the D2cc for the bladder and rectum were evaluated in 18 patients with vaginal cancer.

Results: For the IMBT plans with the 60Co source, the use of the redesigned applicator decreased the D2cc of the bladder and rectum by 11.1% and 12.8%, respectively, while for those with the 192Ir source, the reduction was 16.6% and 18.7%, respectively. Nevertheless, there was an insignificant alteration in the absorbed dose parameter (D90) for the target using both sources.

Conclusion: This study demonstrates that tungsten trioxide nanoparticle/epoxy composite can be advantageous in tackling radiation shielding concerns. Enhancing the shielding properties of this composite, considering the size limitations of applicators, leads to improved protection of organs at risk, such as the bladder and rectum. This substance can be considered a promising shielding material in the construction of applicators.