Intraoperative Radiotherapy Research Articles

Intraoperative radiation therapy for early-stage breast cancer.

Intraoperative radiotherapy (IORT) offers more convenience compared to external beam radiotherapy (EBRT) following breast-conserving surgery for early-stage breast cancer. This study describes the implementation of IORT at a metropolitan academic cancer center. Demographics, tumor characteristics, margin status, adjunct EBRT, and cosmetic results were retrospectively analyzed in patients undergoing BCS with IORT. IORT consists of 20 gray delivered to the partial mastectomy cavity. From 2015 to 2020, 171 patients (65.5% African American) were included. Histologically, 104 (60.8%) patients had invasive ductal carcinoma (IDC), while 67 (39%) patients had DCIS only. Seventeen (15.9%) patients with IDC and 12 (8.6%) patients with DCIS had positive margins. There were 15 ipsilateral breast recurrences (8.8%) and three patients (20%) developed systemic disease. Twenty-five patients (14.6%) underwent adjuvant EBRT. The local recurrence-free survival at 60 months from date of IORT was 89.4% (95% CI 82.7%-93.6%). For overall survival (OS), 168 (98.2%) patients were alive at a median follow-up of 51.4 months, and three total deaths were recorded. IORT is a highly desirable and convenient alternative to EBRT for early-stage breast cancer especially for patients with poor compliance. IORT has an acceptable ipsilateral recurrence while not precluding adjunct EBRT based upon the final pathologic report.

Ultrasound-guided joystick technique for percutaneous leverage reduction with Kirschner wires and external fixator in pediatric proximal humerus fractures: A clinical outcome study

ObjectiveThis study aims to evaluate the clinical application efficacy of the ultrasound-guided Joystick technique for percutaneous leverage reduction in conjunction with Kirschner wires and external fixator in the treatment of difficult-to-reduce pediatric Salter-Harris II type proximal humerus fractures. MethodsA retrospective analysis was conducted on children with Salter-Harris II type proximal humerus fractures, who failed manual closed reduction from January 2018 to March 2022. The group consisted of 7 males and 2 females, aged between 10 and 14 years. The surgical method involved percutaneous leverage reduction using the ultrasound-guided Joystick technique, combined with Kirschner wires and external fixation. Throughout the procedure, ultrasound is used for monitoring, with the fracture condition being determined before surgery. An external support screw is inserted into the distal end of the humerus as an operating lever, along with 3.5 mm Kirschner wire for ultrasound-guided reduction and maintenance of position during the operation. Following fixation with Kirschner wire, a combination external fixator is applied. After fixation is completed, ultrasound is used once more to assess the quality of fracture reduction, followed by verification of the reduction status using a C-arm X-ray machine. ResultsAll surgeries were successfully completed with a 100 % success rate in resetting. Notably, there were no postoperative complications like nerve or vascular injury, malunion, nonunion, or bone bridge formation in the proximal humeral physis. Three cases experienced minor complications (redness and swelling at the screw sites), which improved with conservative management. The follow-up period ranged from 6 to 18 months, averaging 10.6 months, with fracture clinical healing occurring within 6 to 8 weeks (average 6.3 weeks). The final follow-up revealed excellent functional outcomes, with Neer scores ranging from 90 to 100 (average 96.3 points). ConclusionThe ultrasound-guided Joystick technique for percutaneous leverage reduction in conjunction with Kirschner wires and external fixator can effectively treat difficult-to-reduce Salter-Harris II proximal humeral fractures in children, avoiding open reduction and minimizing intraoperative radiation exposure. This approach offers good stability and facilitates early rehabilitation, aligning with the ERAS (Enhanced Recovery After Surgery) concept in fracture management, thus warranting clinical promotion.

Technical note: Determination of for a miniature x-ray source using a soft x-ray ionization chamber calibrated in NIST reference beam qualities.

The formalism proposed by Watson etal. allows users of the INTRABEAM (Carl Zeiss Medical AG, Jena, Germany) electronic brachytherapy system to accurately determine the absorbed dose to water, in the absence of a primary dosimetry standard. However, all published values are for PTW 34013 ionization chambers calibrated in a TW30 reference beam, traceable to PTB (Germany). For North American users, it would be advantageous to have data for chambers calibrated in a kV reference beam maintained by the National Institute of Standards and Technology (NIST). In this work, we determine for a PTW 34013 chamber calibrated in three NIST-traceable reference beams: M30, L40, andL50. Using available photon spectra data for M30, L40, and L50 reference beam qualities, Monte Carlo simulations using EGSnrc were performed to calculate the ratio of the absorbed dose to the PTW 34013 chamber air cavity to air-kerma ( ) for these beams. From this ratio, as a function of depth in water was determined. The effect of the use of a buildup foil was also investigated. An uncertainty analysis considering both the Type A and Type B uncertainties in the calculation of was performed. The largest difference in was found between L50 and TW30, with a relative decrease of 1.4% (no buildup) to 1.6% (buildup). For M30 and L40, the differences were minimal compared with measurementuncertainties. We report values for three NIST-traceable kV reference beams. This study reinforces the feasibility of adapting the Watson etal. methodology using different kV reference beams, facilitating the use of INTRABEAM in North America and ensuring the continuity and accuracy of dosimetry standards in intraoperative radiationtherapy.

Is Ocular Safety in Orthopaedics Overlooked? A Systematic Review of Annual Ocular Radiation Exposure and Protective Measures.

Intraoperative fluoroscopy is increasingly common in orthopaedics, although recent guidelines have reduced the maximum recommended exposure to 20 mSv annually. A systematic review of the literature was conducted to comprehensively assess current adherence to exposure guidelines, identify practice settings at increased risk for exposure, and determine the best practices and personal protective equipment for ocular radiation risk mitigation. In this systematic review we asked: (1) Is the annual amount of eye irradiation received by orthopaedic surgeons below the recommended limit of 20 mSv? (2) What is the effectiveness of leaded glasses in reducing the eye's exposure to radiation? (3) Which imaging setups and operative techniques reduce ocular irradiation? PubMed, Medline, EBSCOhost, and Google Scholar were queried on September 28, 2023, to identify studies assessing intraoperative ocular radiation exposure among orthopaedic surgeons. Studies that measured radiation in or around the eye (such as the bridge of the nose or eyebrows) during orthopaedic procedures were included. Exclusion criteria were duplicate studies, studies that only estimated eye radiation based on the radiation dose recorded at parts of the body distant from the eyes, nonoriginal research, case reports, and articles without full-text English versions available. A total of 393 unique articles were retrieved, and after title, abstract, and full-text screening, 23 dosimetry studies were included, comprising 12 prospective observational studies, 7 phantom models, 1 cadaver model, 2 observational studies, and 1 randomized control trial. Risk of bias was determined via the Methodological Index for Nonrandomized Studies (MINORS) tool. Study quality was generally good to excellent, with noncomparative studies having a mean MINORS score of 14 ± 0 of 16 and comparative studies achieving a mean score of 19 ± 1 of 24, with higher scores representing better study quality. Due to extensive heterogeneity in study design, a meta-analysis was not conducted, with the results rather presented as a narrative summary of key findings. The vast majority of surgeons conducting a variety of orthopaedic and traumatologic procedures were not exposed to a hazardous level of eye irradiation annually, but surgeons who perform a high volume of fluoroscopy-intensive procedures may exceed guidelines. Leaded eyeglasses reduced eye radiation by about 90%, with sport wrap-around glasses offering better shielding than alternatives, although leaded glasses overall were largely underutilized. Positioning mini C-arms in the standard vertical configuration was shown to provide up to a 13-fold decrease in radiation exposure compared with inverted configuration, while standing perpendicular to the fluoroscope further reduced eye irradiation. We found that orthopaedic surgeons who perform a high volume of fluoroscopy-intensive procedures may be at risk of exceeding recommendations on annual radiation exposure, although exposure can be mitigated through various simple strategies. In particular, this analysis found that the use of sport wrap-around leaded glasses, positioning of mini-C arms in the standard vertical configuration, and standing perpendicular to the fluoroscope provide the most effective means of limiting ocular radiation exposure. As ophthalmic radiation exposure presents a potentially important occupational health hazard to orthopaedic surgeons, further investigations of radiation exposure specific to high-volume, fluoroscopy-intensive orthopaedic practices and long-term ophthalmic outcomes will help determine the extent of the potential harm posed by frequent exposure to intraoperative radiation over the span of a career. Level III, therapeutic study.

Intraoperative radiotherapy after neurosurgical resection of brain metastases as institutional standard treatment- update of the oncological outcome form a single center cohort after 117 procedures.

Stereotactic radiotherapy (SRT) is the predominant method for the irradiation of resection cavities after resection of brain metastases (BM). Intraoperative radiotherapy (IORT) with 50kV x-rays is an alternative way to irradiate the resection cavity focally. We have already reported the outcome of our first 40 IORT patients treated until 2020. Since then, IORT has become the predominant cavity treatment in our center due to patients´ choice. We retrospectively analyzed the outcomes of all patients who underwent resection of BM and IORT between 2013 and August 2023 at Augsburg University Medical Center (UKA). We identified 105 patients with 117 resected BM treated with 50kV x-ray IORT. Median diameter of the resected metastases was 3.1cm (range 1.3 - 7.0cm). Median applied dose was 20Gy. All patients received standardized follow-up (FU) including three-monthly MRI of the brain. Mean FU was 14months, with a median MRI FU for patients alive of nine months. Median overall survival (OS) of all treated patients was 18.2months (estimated 1-year OS 57.7%). The observed local control (LC) rate of the resection cavity was 90.5% (estimated 1-year LC 84.2%). Distant brain control (DC) was 61.9% (estimated 1-year DC 47.9%). Only 16.2% of all patients needed WBI in the further course of disease. The observed radio necrosis rate was 2.6%. After 117 procedures IORT still appears to be a safe and appealing way to perform cavity RT after neurosurgical resection of BM with low toxicity and excellent LC.

Intraoperative radiotherapy: An alternative to whole-breast external beam radiotherapy in the management of highly selective breast cancer: A SEER database analysis.

This study aimed to verify if intraoperative radiotherapy (IORT) can achieve the same survival outcome as whole-breast external beam radiotherapy (EBRT) in early breast cancer after breast-conserving surgery (BCS), and to explore the suitable candidates that can safely receive IORT after BCS. Eligible post-BCS patients who received IORT or EBRT were included in the Surveillance, Epidemiology and End Results (SEER) database from 2010 to 2018. Risk factors that affected 5-year overall survival (OS) or breast cancer specific survival (BCSS) were identified by Cox proportional hazards regression analysis. Clinical characteristics, OS, and BCSS were comparatively analyzed between the two treatment modalities. The survival analysis after propensity score matching confirmed that patients who received IORT (n = 2200) had a better 5-year OS than those who received EBRT (n = 2200) (p = 0.015). However, the two groups did not differ significantly in 5-year BCSS (p = 0.381). This feature persisted even after multivariate analyses that took into account numerous clinical characteristics. Although there was no significant difference in BCSS between different subgroups of patients treated with IORT or EBRT, patients over 55 years of age, with T1, N0, non-triple negative breast cancers, hormone receptor-positive, and histologic grade II showed a better OS after receiving IORT. In low-risk, early-stage breast cancer, IORT was not inferior to EBRT considering 5-year BCSS and OS. Considering the equivalent clinical outcome but less radiotoxicity, IORT might be a reasonable alternative to EBRT in highly selective patients undergoing BCS.

Qualitative exploration of patients’ experiences with Intrabeam TARGeted Intraoperative radioTherapy (TARGIT-IORT) and External-Beam RadioTherapy Treatment (EBRT) for breast cancer

ObjectiveTo gather a deep qualitative understanding of the perceived benefits and impacts of External-Beam RadioTherapy (EBRT) and TARGeted Intraoperative radioTherapy (TARGIT-IORT) using Intrabeam to assess how the treatments affected patient/care...

A novel technique for C1-C2 posterior screw insertion using patient-specific guides created by CT-based 3D printing.

C1-C2 fixation has been developed for the rigid fusion of atlantoaxial instability. C1 lateral mass screw (C1 LMS)-C2 pedicle screw fixation is used more frequently due to its rigid fixation and high bone fusion rate. However, C1 screw placement is relatively unsafe even with recently developed image-based navigation systems. Patient-specific screw guide templates (PSGT) were developed to improve the accuracy and safety of C1 screw placement. Herein, we investigated the outcomes of the C1-C2 posterior fixation technique using PSGT. This was a retrospective study of six patients who underwent posterior cervical spinal fusion using the PSGT between January 2022 and April 2023. Operative time, estimated blood loss, intraoperative radiation dose, surgical cost, and screw placement accuracy were evaluated and compared with those achieved with preoperative CT-based navigation (navigation group, n = 15). Screw accuracy was assessed using Neo's classification. PSGT showed good results, although the differences were not statistically significant (operation time: 104.3 ± 9.7 min vs 116.4 ± 20.8 min; estimated blood loss: 56.7 ± 72.4 mL vs 123.2 ± 162.3 mL; and radiation dose: 1.8 ± 1.2 mSv vs 2.6 ± 0.8 mSv, respectively). PSGT was particularly better in terms of the accuracy of C1 LMS (PSGT: 100%, navigation: 83.3%). The deviation at the entry point was minimal, and the difference between the sagittal and transversal angles from the preoperative plan was small. We investigated the clinical efficacy of using the PSGT for C1-C2 posterior fixation. PSGT improved the accuracy of C1 LMS insertion.

Clinical outcomes of guider-assisted osteotomy compared to conventional pendulum-saw osteotomy in open wedge high tibial osteotomy: a propensity score-matched cohort study

PurposeWe developed a novel guider-assisted osteotomy (GAO) procedure to improve the safety of open wedge high tibial osteotomy (OWHTO) and aimed to compare its efficacy and complications with the conventional pendulum-saw osteotomy (PSO).MethodsThis is a retrospective cohort study of patients undergoing either GAO or PSO procedure in the OWHTO to treat varus knee osteoarthritis, who had a minimum of 2 years of follow-up. Patients were propensity score matched (PSM) in a 1:1 ratio based on demographic and clinical data with a caliper width of 0.02. The outcomes assessed involved the hospital for special surgery (HSS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and the Intraoperative and postoperative complications.Results199 patients were included in each group after PSM. The mean duration of follow-up was 38.3 ± 8.9 months. The GAO group had a shorter operation duration (104.5 ± 35.7 vs. 112.1 ± 36.0 min, p = 0.027) and fewer times of intraoperative fluoroscopy (4.2 ± 1.4 vs. 6.0 ± 1.4, p < 0.001). At the last follow-up, clinical scores for knee achieved significant improvements in both GAO and PSO groups: HSS (67.5 ± 10.5 vs. 90.2 ± 7.0, p < 0.001; 69.4 ± 8.2 vs. 91.7 ± 6.8, p < 0.001) and WOMAC (65.7 ± 11.6 vs. 25.2 ± 10.4, p < 0.001; 63.3 ± 12.2 vs. 23.8 ± 9.5, p < 0.001). However, no significant difference was observed between groups for any measures (p > 0.05). In addition, the intraoperative complications (0.5% vs. 3.5%, p = 0.068) and the postoperative bone delayed union and nonunion (1.0% vs. 4.5%, p = 0.032) were marginally or significantly reduced in the GAO versus PSO group.ConclusionGAO demonstrates improvements in intraoperative radiation exposure and complications, with comparable short-term efficacy to PSO, and could be considered a viable alternative in clinical practice.

Local therapy in glioma: An evolving paradigm from history to horizons (Review).

Despite the implementation of multimodal treatments after surgery, glioblastoma (GBM) remains an incurable disease, posing a significant challenge in neuro-oncology. In this clinical setting, local therapy (LT), a developing paradigm, has received significant interest over time due to its potential to overcome the drawbacks of conventional therapy options for GBM. The present review aimed to trace the historical development, highlight contemporary advances and provide insights into the future horizons of LT in GBM management. In compliance with the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols criteria, a systematic review of the literature on the role of LT in GBM management was conducted. A total of 2,467 potentially relevant articles were found and, after removal of duplicates, 2,007 studies were screened by title and abstract (Cohen's κ coefficient=0.92). Overall, it emerged that 15, 10 and 6 clinical studies explored the clinical efficiency of intraoperative local treatment modalities, local radiotherapy and local immunotherapy, respectively. GBM recurrences occur within 2 cm of the radiation field in 80% of cases, emphasizing the significant influence of local factors on recurrence. This highlights the urgent requirement for LT strategies. In total, three primary reasons have thus led to the development of numerous LT solutions in recent decades: i) Intratumoral implants allow the blood-brain barrier to be bypassed, resulting in limited systemic toxicity; ii) LT facilitates bridging therapy between surgery and standard treatments; and iii) given the complexity of GBM, targeting multiple components of the tumor microenvironment through ligands specific to various elements could have a synergistic effect in treatments. Considering the spatial and temporal heterogeneity of GBM, the disease prognosis could be significantly improved by a combination of therapeutic strategies in the era of precision medicine.

The Application of a Surgery Supporting Computer System Does Not Seem to Influence the Surgeons' Radiation Exposure: A Retrospective Analysis.

Since 2019, a surgery supporting system (SPM, surgical process manager; Johnson & Johnson, New Brunswick, New Jersey, Vereinigte Staaten) has been used in a Level I trauma center for common trauma surgery procedures (distal radius fractures, proximal femur fractures, ankle fractures, proximal humerus fractures, and spine fractures). The hypothesis of this study was that implementing standardized procedures (by using SPM) may reduce radiation exposure, especially for unexperienced surgeons.Workflows were developed for different surgical procedures (distal radius fractures, proximal femur fractures, ankle fractures, proximal humerus fractures, and spine fractures) and added into the SPM. Between October 2019 and June 2022, 90 surgeries using the SPM were included in the study. A control group was included with 107 surgeries using the same surgical technique. The values measured were the radiation exposure during the surgical procedure, the experience of the head surgeon, and whether or not the SPM was used. A statistical analysis was performed by using the chi square and Fischer exact tests, with significance set at a p value <0.05.SPM was applicated in 51 cases for the distal radius (control group 54 patients), 20 cases for distal fibula fractures (control group 21 patients), 9 cases for the proximal femur (control group 19 patients), 5 cases for vertebral fractures (control group 7 patients), and 5 cases for the proximal humerus (control group 6 patients). No difference concerning the median radiation exposure was observed by plating distal radius fractures with 5.7Gy/cm² in the SPM group and a median radiation exposure of 6.4Gy/cm² in the control group (p=0.96). The distal fibula fractures showed no significant difference in the intraoperative radiation (17.4Gy/cm² vs. 6.4Gy/cm², p value 0.53). Radiation exposure was lower when a consultant performed surgery without showing any significance, independent if SPM was used or not.In this study, no significant difference in the intraoperative radiation dose was observed when using a surgery supporting computer system. The experience of the surgeon showed no influence as well, regardless if SPM was used or not. Additional data should be collected questioning these findings.

Comparison of robot-assisted versus fluoroscopy-guided transforaminal lumbar interbody fusion (TLIF) for lumbar degenerative diseases: a systematic review and meta-analysis of randomized controlled trails and cohort studies

BackgroundAs an emerging technology in robot-assisted (RA) surgery, the potential benefits of its application in transforaminal lumbar interbody fusion (TLIF) lack substantial support from current evidence.ObjectiveWe aimed to investigate whether the RA TLIF is superior to FG TLIF in the treatment of lumbar degenerative disease.MethodsWe systematically reviewed studies comparing RA versus FG TLIF for lumbar degenerative diseases through July 2022 by searching PubMed, Embase, Web of Science, CINAHL (EBSCO), Chinese National Knowledge Infrastructure (CNKI), WanFang, VIP, and the Cochrane Library, as well as the references of published review articles. Both cohort studies (CSs) and randomized controlled trials (RCTs) were included. Evaluation criteria included the accuracy of percutaneous pedicle screw placement, proximal facet joint violation (FJV), radiation exposure, duration of surgery, estimated blood loss (EBL), and surgical revision. Methodological quality was assessed using the Cochrane risk of bias and ROBINS-I Tool. Random-effects models were used, and the standardized mean difference (SMD) was employed as the effect measure. We conducted subgroup analyses based on surgical type, the specific robot system used, and the study design. Two investigators independently screened abstracts and full-text articles, and the certainty of evidence was graded using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach.ResultsOur search identified 539 articles, of which 21 met the inclusion criteria for quantitative analysis. Meta-analysis revealed that RA had 1.03-folds higher “clinically acceptable” accuracy than FG (RR: 1.0382, 95% CI: 1.0273–1.0493). And RA had 1.12-folds higher “perfect” accuracy than FG group (RR: 1.1167, 95% CI: 1.0726–1.1626). In the case of proximal FJV, our results indicate a 74% reduction in occurrences for patients undergoing RA pedicle screw placement compared to those in the FG group (RR: 0.2606, 95%CI: 0.2063- 0.3293). Seventeen CSs and two RCTs reported the duration of time. The results of CSs suggest that there is no significant difference between RA and FG group (SMD: 0.1111, 95%CI: -0.391–0.6131), but the results of RCTs suggest that the patients who underwent RA-TLIF need more surgery time than FG (SMD: 3.7213, 95%CI: 3.0756–4.3669). Sixteen CSs and two RCTs reported the EBL. The results suggest that the patients who underwent RA pedicle screw placement had fewer EBL than FG group (CSs: SMD: -1.9151, 95%CI: -3.1265–0.7036, RCTs: SMD: -5.9010, 95%CI: -8.7238–3.0782). For radiation exposure, the results of CSs suggest that there is no significant difference in radiation time between RA and FG group (SMD: -0.5256, 95%CI: -1.4357–0.3845), but the patients who underwent RA pedicle screw placement had fewer radiation dose than FG group (SMD: -2.2682, 95%CI: -3.1953–1.3411). And four CSs and one RCT reported the number of revision case. The results of CSs suggest that there is no significant difference in the number of revision case between RA and FG group (RR: 0.4087,95% CI 0.1592–1.0495). Our findings are limited by the residual heterogeneity of the included studies, which may limit the interpretation of the results.ConclusionIn TLIF, RA technology exhibits enhanced precision in pedicle screw placement when compared to FG methods. This accuracy contributes to advantages such as the protection of adjacent facet joints and reductions in intraoperative radiation dosage and blood loss. However, the longer preoperative preparation time associated with RA procedures results in comparable surgical duration and radiation time to FG techniques. Presently, FG screw placement remains the predominant approach, with clinical surgeons possessing greater proficiency in its application. Consequently, the integration of RA into TLIF surgery may not be considered the optimal choice.Systematic review registrationPROSPERO CRD42023441600.

Locoregional Therapy for Early and Locally Advanced Breast Cancer

Objective: The objective of this article is to conduct a comprehensive review of recent advances in locoregional therapies for early and locally advanced breast cancer, emphasizing the integration of these approaches into comprehensive treatment plans. Initially, this study explores contemporary findings related to surgical techniques, radiation therapy, and the integration of systemic treatments, such as targeted therapies and chemotherapy, as part of a cohesive treatment strategy. Theoretical Framework: Breast cancer remains a significant public health issue, with locoregional therapy playing a critical role in the management of early and locally advanced stages of the disease. The evolution of treatment strategies reflects a deepening understanding of the disease's biological behavior and the necessity for tailored therapeutic approaches. Method: A systematic review was conducted using major scientific databases to collect relevant articles on recent advances in locoregional therapy for breast cancer, from surgical innovations to advanced radiation techniques. Specific keywords were used to identify studies that address new findings and interdisciplinary approaches, facilitating the synthesis of effective strategies and the identification of gaps in current research. Results and Discussion: Recent research has improved surgical precision and radiation delivery techniques, reducing side effects and enhancing treatment efficacy. Innovations in intraoperative radiation and the growing use of neoadjuvant therapies offer promising results, optimizing tumor control and preserving patient quality of life. However, challenges remain in achieving consistent results across different patient populations, underscoring the need for personalized treatment plans tailored to individual patient characteristics and tumor biology.

The Lateral Para-Patellar Approach for Intramedullary Tibia Nailing in Distal Tibia Extra-articular Fractures: A Prospective Cohort Study.

The treatment of extra-articular distal tibiafractures is still a subject of debate and frequently necessitates surgical treatment, and intramedullary nailing (IMN) offers a minimally invasive approach with excellent results. Important factors in these procedures are positioning, operative duration, and radiation exposure. This study details the semi-extended lateral para-patellar approach for IMN of distal tibia extra-articular fractures and documents our findings regarding operative time, intra-operative radiation exposure, residual anterior knee pain, knee functional and radiological outcomes at six months follow-up. We reviewed the cases of 60 patients who underwent IMNfor distal tibia extra-articular fractures from May 2022 to March 2024, employing an extra-articular lateral para-patellar approach in the semi-extended position. Patients were evaluated clinically and radio-graphically for a minimum follow-up period of six months. Data collected included duration of surgery, intraoperative radiation exposure, and knee functional scorefor all patients. Assessment of fracture healing, residual deformities, residual anterior knee pain, and range of motion of the treated knee compared to the contralateral knee was done at a six-monthfollow-up. The average surgery duration was 54 ± 5 minutes, with intraoperative imaging averaging 48 exposures. The average time to union was 16 ± 3 weeks. Six months post-surgery, the mean Knee Society Score was 86.4 ± 3.5 (out of 100). At the six months follow-up, all patients exhibited clinical and radiographic healing, with only two cases showing mal-alignment (angular deformity <10 degrees).All patients regained a comparable range of motion in their knees. The semi-extended lateral para-patellar approachfor nailing of distal tibiaextra-articular fracturesenhances reduction, simplifies nail insertion,reduces both fluoroscopy and operative time, minimizes anterior knee pain and improves knee functional outcomes at six months follow-up.

Expert Commentary on Use of Intraoperative Radiation Therapy in Rectal Cancer.

Expert Commentary on Use of Intraoperative Radiation Therapy in Rectal Cancer.

Use of Intraoperative Radiation Therapy in Rectal Cancer.

Use of Intraoperative Radiation Therapy in Rectal Cancer.

Development and verification of an electron Monte Carlo engine for applications in intraoperative radiation therapy.

In preparation of future clinical trials employing the Mobetron electron linear accelerator to deliver FLASH Intraoperative Radiation Therapy (IORT), the development of a Monte Carlo (MC)-based framework for dose calculation was required. To extend and validate the in-house developed fast MC dose engine MonteRay (MR) for future clinical applications in IORT. MR is a CPU MC dose calculation engine written in C++ that is capable of simulating therapeutic proton, helium, and carbon ion beams. In this work, development steps are taken to include electrons and photons in MR are presented. To assess MRs accuracy, MR generated simulation results were compared against FLUKA predictions in water, in presence of heterogeneities as well as in an anthropomorphic phantom. Additionally, dosimetric data has been acquired to evaluate MRs accuracy in predicting dose-distributions generated by the Mobetron accelerator. Runtimes of MR were evaluated against those of the general-purpose MC code FLUKA on standard benchmark problems. MR generated dose distributions for electron beams incident on a water phantom match corresponding FLUKA calculated distributions within 2.3% with range values matching within 0.01mm. In terms of dosimetric validation, differences between MR calculated and measured dose values were below 3% for almost all investigated positions within the water phantom. Gamma passing rate (1%/1mm) for the scenarios with inhomogeneities and gamma passing rate (3%/2mm) with the anthropomorphic phantom, were>99.8% and 99.4%, respectively. The average dose differences between MR (FLUKA) and the measurements was 1.26% (1.09%). Deviations between MR and FLUKA were well within 1.5% for all investigated depths and 0.6% on average. In terms of runtime, MR achieved a speedup against reference FLUKA simulations of about 13 for 10 MeV electrons. Validations against general purpose MC code FLUKA predictions and experimental dosimetric data have proven the validity of the physical models implemented in MR for IORT applications. Extending the work presented here, MR will be interfaced with external biophysical models to allow accurate FLASH biological dose predictions in IORT.

Concurrent hyperthermic intraperitoneal chemotherapy and intraoperative radiotherapy with cytoreductive surgery in patients with rectal cancer with peritoneal carcinomatosis.

e15571 Background: Rectal cancer (RC) is often associated with peritoneal carcinomatosis (PC). Hyperthermic intraperitoneal chemotherapy (HIPEC) and intraoperative radiotherapy (IORT) have been shows to reduce recurrence and effectively treat PC across several cancers. However, little evidence is available regarding the concurrent use of HIPEC and IORT alongside cytoreductive surgery (CRS) in the literature. Methods: We retrospectively reviewed the medical records of RC patients with PC who received HIPEC plus IORT during CRS at the King Faisal Specialist Hospital and Research Centre. Demographic data, PC index (PCI), completeness of cytoreduction (CC), and tumor staging were collected. Overall survival (OS) was calculated from the time of surgery until death or last follow-up. Recurrence-free survival (RFS) was calculated from the time of surgery until recurrence or last follow-up. Unadjusted hazard ratios (HR) were used to determine the impact of parameters on OS or RFS. Results: 17 patients were included in our analysis. Basic demographic data can be found in Table 1. The most common operation performed was rectosigmoid resection in 7 (41.2%) patients, followed by low anterior resection in 6 (35.3%). The pT stage was T0 in 1 (5.9%), T4a in 7 (41.2%), and T4b in 9 (52.9%). The pN stage was N0 in 11 (64.7%), N1a in 1 (5.9%), N1b in 2 (11.8%), N1c in 2 (11.8%), and N2b in 1 (5.9%). There was positive resection margin in 2 patients. The PCI was ≤6 in 15 (88.2%), and the CC score was 0-1 in all patients. No patients had intraoperative complications. 12 (70.6%) received mitomycin C, 4 (23.5%) received cisplatin and mitomycin C, and one patient received a reduced dose of mitomycin C due to old age. 2 (11.8%) patients received two doses of IORT. 11 (64.7%) patients had postoperative complications, of which all were Clavein-Dindo grades 1-3b. Recurrence occurred in 11 (64.7%). The median OS was not reached, and the median RFS was 12 months. There were no parameters associated with OS. Male gender (HR: 7.7, 95% CI: 1.4-57.3), pM1 (HR: 4.5, 95% CI; 1.2-18.1), and perineural invasion (HR: 6.5, 95% CI: 1.2-49.3) were associated with poor RFS in univariate analysis. Conclusions: Incorporating HIPEC and IORT into CRS may be an effective treatment strategy for RC patients. Presence of distant metastasis and perineural invasion can be predictors of rapid recurrence. [Table: see text]

Retrospective study on the profile of patients undergoing intraoperative radiotherapy with INTRABEAM for breast cancer treatment at a Brazilian cancer center.

e12538 Background: Conservative breast therapy combined with adjuvant radiotherapy has been the preferred treatment for early-stage breast cancer for many decades. Considering that most breast cancer recurrences occur near the original tumor site, partial breast radiotherapy has become an alternative for patients in this scenario, allowing for a single-dose radiation application directly to the tumor site. This technique has advantages such as reducing local toxicity and improving the quality of life for treated patients, in addition to decreasing the waiting time for radiotherapy treatment in developing countries like ours. Our case series is the largest in Latin America to date, and we believe that reporting the results of our experience will be valuable for the scientific community and aid in treatment decision-making in low- and middle-income countries. Methods: This is a retrospective study based on data from the medical records of 209 patients with early-stage breast cancer undergoing conservative surgery and intraoperative radiotherapy at A.C. Camargo Cancer Center (São Paulo, Brazil) from 2016 to 2023. Results: In our cohort, 88.5% of tumors were invasive ductal carcinomas. The majority were T1b (41.8%), had histological grade 2 (45.4%), nuclear grade 2 (62.7%), and showed no axillary involvement (87.6%). All patients received intraoperative radiotherapy in a single dose of 20 Gy radiation at the tumor site with a voltage of 50 kV. In our study, 17.7% of patients required additional external radiotherapy due to postoperative histopathological findings inconsistent with treatment indication criteria, including 35.3% for micrometastasis and 32.4% for nodal macrometastasis, 10.8% for narrow or compromised margins, 10.8% for histological types not covered in the final report, 2.7% for multifocality, 2.7% for extensive ductal carcinoma in situ, 2.7% for negative progesterone receptor, and 2.7% for the presence of lymphatic vascular invasion. The average follow-up time for patients was 36 months. The local recurrence rate was 0.5%. Conclusions: The results of this study support established data indicating the efficacy of intraoperative radiotherapy in early-stage breast cancer treatment. Therefore, for carefully selected patients, this technique with should be considered as a treatment option. We will continue to follow this patient cohort to identify the occurrence of late recurrences and publish long-term follow-up data.

Treatment of colon cancer using a novel approach comprising cytoreductive surgery in combination with hyperthermic intraperitoneal chemotherapy and intraoperative radiation therapy.

e15573 Background: Approximately 10% of colon cancer (CCa) develop peritoneal carcinomatosis. Studies have found that the administration of hyperthermic intraoperative chemotherapy (HIPEC) during cytoreductive surgery (CRS) can reduce the risk of recurrence and development of peritoneal carcinomatosis (PC). Additionally, intraoperative radiotherapy (IORT) has been shown to effectively treat and blunt neoplasm growth. However, no reports of the impact of concurrent HIPEC and IORT in CRS on CCa are available. Methods: We retrospectively reviewed the medical records of CCa patients with PC who received HIPEC and IORT during CRS. Demographics, treatment details, PC indexes (PCI), completeness of cytoreduction scores (CCS), and operative complications were recorded. Subsequently, overall survival (OS) was defined as the time period from surgery until death or loss of follow-up, and recurrence-free survival (RFS) was defined as the period from surgery until recurrence or loss of follow-up. Univariate hazard ratios (HR) were used to check for prognostic factors. Results: 17 CCa patients were included in our analysis. Patient characteristics are summarized in Table 1. The pT staging was T0 in 1 (5.9%), T3 in 6 (35.3%), T4a in 4 (23.5%), and T4b in 6 (35.3%). The pN staging was N0 8 (47.1%), N1a in 4 (23.5%), N1b in 2 (11.8%), N1c in 2 (11.8%), and N2b in 1 (5.9%). Finally, the pM staging was M0 in 8 (47.1%), M1a in 4 (23.5%), M1b in 2 (11.8%), and M1c in 3 (16.4%). PCI was ≤6 in 13 (76.5%) patients. The CCS was 0-1 in all, but two, patients. 1 patient had a positive resection margin. 8 (47.1%) received cisplatin with mitomycin C during HIPEC, followed by mitomycin alone (29.4%), reduced doses of cisplatin + mitomycin C (17.6%), and a reduced dose of mitomycin C alone (5.9%). Reduced dosage was due to old age in 3 and renal impairment in 1 patient. There were no intraoperative complications or HIPEC-related adverse effects. Two patients received two doses of IORT. 4 (23.5%) patients had postoperative complications, of which two complications were Clavein-Dindo grade 4a. Recurrence occurred in 8 (47.1%) patients, and 4 (23.5%) patients passed away. The median OS was not reached, and the RFS was 19 months. PCI &gt; 6 (HR: 12.6, 95% CI: 1.6-256.8) and postoperative complication of grade 4 (HR: 8.6, 95% CI: 1-73) were associated with poor OS. Only PCI &gt; 6 was associated with poor RFS (HR: 10.4, 95% CI: 1.7-80.8). Conclusions: Postoperative complications in HIPEC+IORT during CRS are comparable to other accepted treatments for CCa. Large, double-arm studies are needed to compare the effectiveness of this treatment. [Table: see text]