Intraoperative Radiotherapy Research Articles

Differences in Intraoperative Fluoroscopic Radiation Exposure During Ankle Fracture Open Reduction and Internal Fixation Between Orthopaedic Surgery and Podiatry.

Surgical ankle fractures pose a unique situation because both podiatrists and orthopaedic surgeons manage these injuries. Intraoperative fluoroscopy is routinely used; however, excessive radiation can be harmful to both the patient and the surgical team. The primary goal of this study was to determine whether there is a difference in the amount of intraoperative radiation exposure during ankle fracture open reduction and internal fixation (ORIF) when performed by orthopaedic surgeons versus podiatrists. This is a retrospective review of patients who underwent ankle fracture ORIF at an urban level I trauma center between January 1st, 2018, and April 1st, 2023. The electronic health record was queried using International Classification of Diseases nine and 10 codes associated with ankle fractures. Patients aged older than 18 years with an ankle fracture managed surgically were included. Subjects were then stratified by procedure. The mean total radiation dose (mRad) and mean total fluoroscopic time (seconds) were then compared between those performed by orthopaedic surgeons and podiatrists. Of the 333 included procedures, 186 were done by orthopaedic surgeons and 147 were done by podiatrists. Using multiple linear regression analysis to control for age, sex, race, ethnicity, and body mass index, patients undergoing isolated malleolus ORIF with syndesmosis repair performed by orthopaedic surgery were found to have a significantly lower mean fluoroscopic time compared with those performed by podiatry (68.4 s versus 104.8 s; P = 0.028). In addition, trimalleolar ORIF with syndesmotic repair performed by orthopaedic surgery had a significantly lower mean total radiation dose compared with those performed by podiatry (244.6 mRad v 565.6 mRad; P = 0.009). Patients and surgical teams are exposed to markedly less radiation in isolated malleolar and trimalleolar fracture ORIF with syndesmosis repair when performed by an orthopaedic surgeon as compared with those performed by a podiatrist.

SA10 The Safety and Effectiveness of Intraoperative Radiotherapy With Low-Energy X-Ray for Breast Cancer: A Systematic Review

SA10 The Safety and Effectiveness of Intraoperative Radiotherapy With Low-Energy X-Ray for Breast Cancer: A Systematic Review

Acute and Long-Term Toxicity after Planned Intraoperative Boost and Whole Breast Irradiation in High-Risk Patients with Breast Cancer-Results from the Targeted Intraoperative Radiotherapy Boost Quality Registry (TARGIT BQR).

In the context of breast cancer treatment optimization, this study prospectively examines the feasibility and outcomes of utilizing intraoperative radiotherapy (IORT) as a boost in combination with standard external beam radiotherapy (EBRT) for high-risk patients. Different guidelines recommend such a tumor bed boost in addition to whole breast irradiation with EBRT for patients with risk factors for local breast cancer recurrence. The TARGIT BQR (NCT01440010) is a prospective, multicenter registry study aimed at ensuring the quality of clinical outcomes. It provides, for the first time, data from a large cohort with a detailed assessment of acute and long-term toxicity following an IORT boost using low-energy X-rays. Inclusion criteria encompassed tumors up to 3.5 cm in size and preoperative indications for a boost. The IORT boost, administered immediately after tumor resection, delivered a single dose of 20 Gy. EBRT and systemic therapy adhered to local tumor board recommendations. Follow-up for toxicity assessment (LENT SOMA criteria: fibrosis, teleangiectasia, retraction, pain, breast edema, lymphedema, hyperpigmentation, ulceration) took place before surgery, 6 weeks to 90 days after EBRT, 6 months after IORT, and then annually using standardized case report forms (CRFs). Between 2011 and 2020, 1133 patients from 10 centers were preoperatively enrolled. The planned IORT boost was conducted in 90%, and EBRT in 97% of cases. Median follow-up was 32 months (range 1-120, 20.4% dropped out), with a median age of 61 years (range 30-90). No acute grade 3 or 4 toxicities were observed. Acute side effects included erythema grade 1 or 2 in 4.4%, palpable seroma in 9.1%, punctured seroma in 0.3%, and wound healing disorders in 2.1%. Overall, chronic teleangiectasia of any grade occurred in 16.2%, fibrosis grade ≥ 2 in 14.3%, pain grade ≥ 2 in 3.4%, and hyperpigmentation in 1.1%. In conclusion, a tumor bed boost through IORT using low-energy X-rays is a swift and feasible method that demonstrates low rates in terms of acute or long-term toxicity profiles in combination with whole breast irradiation.

Intraoperative Ionizing Radiation Exposure Awareness and Associated Morbidity in Neurosurgery: A Nationwide Survey

Neurosurgeons often use radiation to visualize blood vessels and implants intraoperatively. However, high exposure to radiation increases one's cancer risk. This study aims to investigate intraoperative ionizing radiation exposure awareness and associated morbidity among neurosurgeons. An anonymized 30-question survey about their intraoperative radiation exposure, protective measures, radiation knowledge, and any conditions that can arise from protracted radiation exposure was disseminated to 3344 American Association of Neurological Surgeons members. A total of 227 (6.8%) neurosurgeons completed the survey. Most neurosurgeons (61, 27%) performed 2-4 surgeries per week necessitating radiation (61, 27%), did not use a dosimeter (134, 59%), and wore a lead apron (89%) and a thyroid shield (75%). Only 7 (3%) of respondents could correctly identify the safety limit for occupational radiation. One hundred and thirty-four (59%) respondents correctly identified the relationship between distance and radiation dose reduction. Two hundred and thirteen (94%) neurosurgeons reported concern about occupational radiation exposure. No significant association was found between occupational radiation exposure and the rate of cataracts, combined cancer, and skin cancer. Multivariate logistic regression adjusting for age and cancer history found that the likelihood of developing leukemia (P= 0.02) and nonmalignant thyroid nodular disease (P= 0.01) is positively associated with increased total occupational radiation exposure. There is a need for improved radiation safety awareness among neurosurgeons, especially in the context of rising usage of minimally invasive surgery. This can allow for a greater understanding of radiation-associated risks among neurosurgeons and guide the implementation of safer practices.

Genotype, phenotype and outcomes of patients with hypertrophic cardiomyopathy referred for ablation of ventricular tachycardia

Abstract Background Sustained monomorphic ventricular tachycardia (SMVT) is the most common ventricular arrhythmia (VA) subtype in patients with hypertrophic cardiomyopathy (HCM) who have received an implantable cardioverter defibrillator (ICD). However, data on catheter ablation (CA) are limited and available series typically report results of non-genotyped patients with relatively mild hypertrophy and/or apical aneurysms. Purpose This study describes genotype, phenotype and outcome of consecutive HCM patients referred for CA ablation of refractory SMVT. Methods and results Nine out of 787 patients referred for catheter ablation of SMVT between 01/2016 – 10/2023 had a HCM phenotype, 8/9 with dominant septal hypertrophy, none with LV outflow tract obstruction, and only 1/9 with an apical aneurysm. The median maximal wall thickness was 25 mm (IQR 20,2 – 26,9 mm) and the median left ventricular ejection fraction 34 % (IQR 26-42%). Six patients had a class IV/V variant in the myosine binding protein C (MYBPC3) gene, in 3 no disease-causing variant was identified. All patients with MYBPC3 mutation presented with an electrical storm/incessant VT refractory to antiarrhythmic drugs (AAD), including amiodarone (6/6) and amiodarone + class I AAD (3/6). In an attempt to control VT, 4/6 patients with a MYBPC3 variant required ≥2 ablation including bail out strategies (transcoronary alcohol-ablation, bipolar ablation, half-saline), surgical substrate resection and intraoperative cryoablation (3/6) and radiotherapy (2/6). After a median follow-up of 25 months (IQR 2-75) after the last intervention, all patients with MYBPC3-variants had VT recurrence, 3/6 died and 1/6 underwent heart transplantation. In contrast, patients without class IV/V variants, did not require bail-out strategies; VT recurred in one (single episode) and one patient died, 24 months after CA. The time course of the disease, management and outcome for patients with and without disease causing mutation is illustrated, with the first ablation as center line (figure). Conclusions Only 1 % of patients referred for CA of SMVT to a high-volume center had a HCM phenotype. A MYBPC3 variant was identified in 67%, and, in contrast to prior reports, 89% had severe hypertrophy. VT free survival appears to be particularly poor in MYBPC3 variant carriers despite availability of all treatment modalities. In these patients, early screening for advanced heart failure management including heart transplantation is important.

Pulsed-field ablation of atrial fibrillation in elderly and frail patients: procedural efficacy and safety from a single-center experience

Abstract Introduction The demographic data shows a growing population, mostly elderly and with multiple comorbidities, therefore becoming increasingly frail. In this context Atrial fibrillation (AF) is the predominant sustained arrhythmia, and over the years trans-catheter isolation of pulmonary veins (PVI) has become a crucial approach in AF treatment. Among the technologies and energy resources employed through the years to perform atrial fibrillation transcatheter ablation, a novel technique has recently begun to gain ground, specifically pulsed-field ablation (PFA). PFA employs sequential brief and high amplitude electrical pulses to induce selective and irreversible electroporation of the myocardium, leading to cell death. The high selectivity of the lesion, ensured by the lower electroporation threshold of myocardial tissue compared to adjacent anatomic structures, allows for a decrease in potential complications associated with conventional thermal ablation. Purpose To assess the efficacy and safety in the use of pulsed field ablation in a selected population of elderly and frail patients undergoing atrial fibrillation ablation. Method We conducted a retrospective study focusing on elderly and frail patients admitted to our centre for paroxysmal or persistent AF ablation. The inclusion criteria were: age greater than 75 years and a Clinical Frailty Scale ≥ 5. The study population consisted of 26 patients [male gender 18, mean age 78 ± 3 years] including 8 who were affected by an oncological or haematological disease at the time of admission. The majority of patients were affected by paroxysmal AF while two of them presented persistent AF (9%). The primary ablation endpoint was the pulmonary vein isolation (PVI) that was achieved by delivering an energy of 2 kV over 8 applications, employing an alternating approach between the two configurations of the basket and flower catheter for each individual vein. Results The short-term success, represented by the complete and verified electrical isolation of the veins was achieved in all 26 patients without any periprocedural complications. First-pass pulmonary vein isolation (FPI) was universally achieved among the patient in study, with a mean skin-to-skin procedural time of 70 ± 30 minutes. From the procedural data perspective, ablation was achieved using an average fluoroscopy time of 22 ± 8.4 minutes and an average dose area product (DAP) of 1320 cGy×cm2. Conclusions In elderly and frail patients, we assessed the efficacy and safety of ablative procedures using the PFA technique. Successful electrical PVI was achieved without additional touch-ups, thanks to a high FPI rate. This results in lower procedural times and shorter intra-operative radiation exposure. These data confer an augmented value within the elderly-frail population, wherein shorter procedural times contribute to a better postoperative course, characterized by reduced bed rest and shorter intra-hospitalization periods.

Calibration and validation of a bleeding detector for beveled PMMA applicators in electron intraoperative radiotherapy

This study aimed to calibrate and validate a capacitive-sensor bleeding detector, originally designed for flat applicators, with beveled applicators (bPMMA), which are among the most commonly used applicators in intraoperative radiotherapy with electron mobile linacs. The detector will help prevent dose misadministration during irradiation in the event of fluid accumulation in the applicator, thus allowing for appropriate intervention. The handicap with employing this detector for bPMMA stems from the fact that the level of accumulated fluid depends on both the tilting angle and orientation of the applicator. Furthermore, the fluid remains accumulated at the bottom corner of the applicator, reducing the sensitivity of the sensor. A 5-strip capacitive sensor has been used, attached to a 4 cm diameter 30° beveled applicator with a tilting angle range from 0° to 30°. The sensor is read out using dedicated electronics, including a Wheatstone bridge circuit, amplifier, filter stages, and microcontroller. To calculate the sensitivity of the sensor, a prior calibration of the circuit has been carried out in order to obtain the relationship between the output voltage of the conditioning circuit and the height of the fluid present in the applicator for different inclinations. Using the average sensitivity over the inclination range of interest can provide accurate measurements of the estimated fluid height up to 12 mm, with a maximum deviation of approximately 2.0 mm and less than 1.0 mm for the 5 mm clinic threshold. The use of the mean sensitivity is a practical approach for detecting bleeding in beveled applicators because it simplifies the measurement process by avoiding the need to obtain detector sensitivity for each inclination and orientation of the applicator, which would be complex if not impractical in clinical use.

Breast conserving surgery with intraoperative electron beam radiation therapy for low-risk breast cancer: Five-year follow-up of 306 patients.

Recent studies have reported a higher than expected risk of ipsilateral breast tumor recurrence (IBTR) after breast conserving surgery (BCS) and a single dose of electron beam intra-operative radiotherapy (IORT). This finding was the rationale to perform a retrospective single center cohort study evaluating the oncologic results of consecutive patients treated with BCS and IORT. Women were eligible if they had clinical low-risk (N0, ≤2 cm unifocal, Bloom and Richardson grade 1-2), estrogen receptor-positive and human-epidermal-growth-factor-receptor-2-negative breast cancer. Prior to BCS, pN0 status was determined by sentinel lymph node biopsy. Data on oncologic follow-up were analyzed. Between 2012 and 2019, 306 consecutive patients were treated and analyzed, with a median age of 67 (50-86) years at diagnosis. Median follow-up was 60 (8-120) months. Five-year cumulative risk of IBTR was 13.4% (95% confidence interval [CI] 9.4-17.4). True in field recurrence was present in 3.9% of the patients. In 4.6% of the patients, the IBRT was classified as a local recurrence due to seeding of tumor cells in the cutis or subcutis most likely related to percutaneous biopsy. In 2.9% of the patients, the IBRT was a new outfield primary tumor. Three patients had a regional lymph node recurrence and two had distant metastases as first event. One breast cancer-related death was observed. Estimated 5-year overall survival was 89.8% (95% CI 86.0-93.6). In conclusion, although some of IBTR cases could have been prevented by adaptations in biopsy techniques and patient selection, BCS followed by IORT was associated with a substantial risk of IBTR.

Intraoperative radiation therapy for brain metastasis in apregnant patient: acase report.

We present the rare case of a42-year-old woman with oligometastatic lung adenocarcinoma in her first trimester of pregnancy who was treated for brain metastases with metastasectomy and intraoperative radiation therapy (IORT) using the INTRABEAM® system (Zeiss AG, Jena, Germany). This case underscores the potential of IORT in optimizing cancer treatment while safeguarding fetal health in pregnant patients.

Extracellular volume-based scoring system for tracking tumor progression in pancreatic cancer patients receiving intraoperative radiotherapy

ObjectivesTo investigate the value of extracellular volume (ECV) derived from portal-venous phase (PVP) in predicting prognosis in locally advanced pancreatic cancer (LAPC) patients receiving intraoperative radiotherapy (IORT) with initial stable disease (SD) and to construct a risk-scoring system based on ECV and clinical-radiological features.Materials and methodsOne hundred and three patients with LAPC who received IORT demonstrating SD were enrolled and underwent multiphasic contrast-enhanced CT (CECT) before and after IORT. ECV maps were generated from unenhanced and PVP CT images. Clinical and CT imaging features were analyzed. The independent predictors of progression-free survival (PFS) determined by multivariate Cox regression model were used to construct the risk-scoring system. Time-dependent receiver operating characteristic (ROC) curve analysis and the Kaplan–Meier method were used to evaluate the predictive performance of the scoring system.ResultsMultivariable analysis revealed that ECV, rim-enhancement, peripancreatic fat infiltration, and carbohydrate antigen 19-9 (CA19-9) response were significant predictors of PFS (all p < 0.05). Time-dependent ROC of the risk-scoring system showed a satisfactory predictive performance for disease progression with area under the curve (AUC) all above 0.70. High-risk patients (risk score ≥ 2) progress significantly faster than low-risk patients (risk score < 2) (p < 0.001).ConclusionECV derived from PVP of conventional CECT was an independent predictor for progression in LAPC patients assessed as SD after IORT. The scoring system integrating ECV, radiological features, and CA19-9 response can be used as a practical tool for stratifying prognosis in these patients, assisting clinicians in developing an appropriate treatment approach.Critical relevance statementThe scoring system integrating ECV fraction, radiological features, and CA19-9 response can track tumor progression in patients with LAPC receiving IORT, aiding clinicians in choosing individual treatment strategies and improving their prognosis.Key PointsPredicting the progression of LAPC in patients receiving IORT is important.Our ECV-based scoring system can risk stratifying patients with initial SD.Appropriate prognostication can assist clinicians in developing appropriate treatment approaches.Graphical

Abstract PO2-22-04: Median Five-Year Follow-Up Results from the Multi-Institution Trial for the Treatment of Early-Stage Breast Cancer Using Intra-Operative Electronic Brachytherapy

Abstract Background: An IRB-approved single arm prospective multi-institution trial was designed to determine the efficacy and outcome of single fraction 20 Gy intra-operative radiation therapy (IORT) using disposable balloon electronic brachytherapy at the time of breast conserving surgery for early-stage breast cancer (women at least 40 years old, infiltrating ductal carcinoma [IDC] or ductal carcinoma in situ [DCIS], single lesion no larger than 3 cm, pN0). Ipsilateral breast tumor recurrences (IBTR) at median 5-year follow-up, the primary protocol endpoint of the trial, would be analyzed with outcomes compared to reported whole breast radiation therapy (WBRT) results. Methods: Between May 2012–July 2018,1199 enrolled breast cancer patients at twenty-six national and international institutions were successfully treated per protocol with lumpectomy plus single 20 Gy fraction IORT using disposable balloon electronic brachytherapy. Data collection and retrospective chart review included demographics, treatment, histopathology, toxicity, IBTR (defined as recurrence in the lumpectomy cavity/index quadrant), and survival. Results: All subjects were successfully treated with a single 20 Gy fraction of IORT. IORT cohort characteristics of the treated subjects are summarized in Table 1. Sixty-six (5.5%) patients received subsequent unplanned risk-adjusted WBRT. At median 5.0-year follow-up (range 0.5 – 9 years), there were 42 (3.50%) IBTR. The original mean tumor size of patients with IBTR was 13.6mm (range 0.03 - 30mm). The mean time to IBTR was 47.6 months (range 12 – 98 months). There were 30 IBTR in patients originally diagnosed with IDC, and 12 IBTR among patients originally diagnosed with DCIS. Three patients originally diagnosed with IDC recurred as DCIS, while 4 patients with DCIS recurred as IDC. The remainder recurred with the same pathology as their original diagnoses. Sorting by 2017 ASTRO accelerated partial breast irradiation (APBI) criteria, there were 25 IBTR in patients categorized immediately following lumpectomy plus IORT as Suitable, 12 IBTR among patients categorized immediately following lumpectomy plus IORT as Cautionary, and 5 IBTR in patients categorized immediately following lumpectomy plus IORT as Unsuitable. Nine (0.75%) patients experienced new ipsilateral primary breast cancers, with 8 classified as Suitable and one as Cautionary using post-lumpectomy plus IORT ASTRO APBI criteria. Seventeen (1.4%) patients experienced acute serious adverse events (SAEs). These included 5 wound infections, 4 hematomas, 2 skin ulcerations, 2 cellulitis, 2 seromas, 1 skin necrosis, and 1 wound dehiscence. All SAEs resolved within 6 months of IORT. One patient died of breast cancer metastases at 3-year follow-up. One patient who was diagnosed with IBTR at 3-year follow-up died 3 years later from dementia. There were 45 unrelated patient deaths. Conclusions: At median 5.0-year follow-up, the 1199 early-stage breast cancer patients successfully treated in this multi-institution trial with a single 20 Gy fraction of IORT to the lumpectomy cavity at the time of partial mastectomy experienced an IBTR of 3.50%. This recurrence rate is acceptable when compared to the 0.9% - 2.5% IBTR reported for WBRT, given the benefits of IORT (convenience, decreased exposure to XRT, better cosmetic outcome, patient preference). Table 1. IORT cohort characteristics Citation Format: Barbara Schwartzberg, AM Nisar Syed, Ajay Bhatnagar, Sophia Rahman, Veronica Jones, Albert Chang, Todd Cockerham, Virginia Osborn, Robert Cohen, Charles Hodge, Christina Lopez-Penalver, Bapsi Chakravarthy, William Dooley, Chika Madu, Atsuko Okabe, Maen Farha, Andrea Madrigrano, Christopher Morrison, Geoffrey Neuner, Craig Wengler, Steven David, Katayoon Toosie, Bryon Stephens. Median Five-Year Follow-Up Results from the Multi-Institution Trial for the Treatment of Early-Stage Breast Cancer Using Intra-Operative Electronic Brachytherapy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-22-04.

2753: A nomogram for predicting local recurrence risk in breast cancer after intraoperative radiotherapy

2753: A nomogram for predicting local recurrence risk in breast cancer after intraoperative radiotherapy

Biological effects of intraoperative radiation therapy: histopathological changes and immunomodulation in breast cancer patients.

Intraoperative radiation therapy (IORT) delivers a single accelerated radiation dose to the breast tumor bed during breast-conserving surgery (BCS). The synergistic biologic effects of simultaneous surgery and radiation remain unclear. This study explores the cellular and molecular changes induced by IORT in the tumor microenvironment and its impact on the immune response modulation. Patients with hormone receptor (HR)-positive/HER2-negative, ductal carcinoma in situ (DCIS), or early-stage invasive breast carcinoma undergoing BCS with margin re-excision were included. Histopathological evaluation and RNA-sequencing in the re-excision tissue were compared between patients with IORT (n=11) vs. non-IORT (n=11). Squamous metaplasia with atypia was exclusively identified in IORT specimens (63.6%, p=0.004), mimicking DCIS. We then identified 1,662 differentially expressed genes (875 upregulated and 787 downregulated) between IORT and non-IORT samples. Gene ontology analyses showed that IORT was associated with the enrichment of several immune response pathways, such as inflammatory response, granulocyte activation, and T-cell activation (p<0.001). When only considering normal tissue from both cohorts, IORT was associated with intrinsic apoptotic signaling, response to gamma radiation, and positive regulation of programmed cell death (p<0.001). Using the xCell algorithm, we inferred a higher abundance of γδ T-cells, dendritic cells, and monocytes in the IORT samples. IORT induces histological changes, including squamous metaplasia with atypia, and elicits molecular alterations associated with immune response and intrinsic apoptotic pathways. The increased abundance of immune-related components in breast tissue exposed to IORT suggests a potential shift towards active immunogenicity, particularly immune-desert tumors like HR-positive/HER2-negative breast cancer.

Intraoperative radiotherapy combined with spinal stabilization surgery—a novel treatment strategy for spinal metastases based on a first single-center experiences

IntroductionCurrent treatment of spinal metastases (SM) aims on preserving spinal stability, neurological status, and functional status as well as achieving local control. It consists of spinal surgery followed by radiotherapy and/or systemic treatment. Adjuvant therapy usually starts with a delay of a few weeks to prevent wound healing issues. Intraoperative radiotherapy (IORT) has previously been successfully applied during brain tumor, breast and colorectal carcinoma surgery but not in SM, including unstable one, to date. In our case series, we describe the feasibility, morbidity and mortality of a novel treatment protocol for SM combining stabilization surgery with IORT.MethodsSingle center case series on patients with SM. Single session stabilization by navigated open or percutaneous procedure using a carbon screw-rod system followed by concurrent 50 kV photon-IORT (ZEISS Intrabeam). The IORT probe is placed via a guide canula using navigation, positioning is controlled by IOCT or 3D-fluroscopy enabling RT isodose planning in the OR.Results15 (8 female) patients (71 ± 10y) received this treatment between 07/22 and 09/23. Median Spinal Neoplastic Instability Score was 8 [7–10] IQR. Most metastasis were located in the thoracic (n = 11, 73.3%) and the rest in the lumbar (n = 4, 26.7%) spine. 9 (60%) patients received open, 5 (33%) percutaneous stabilization and 1 (7%) decompression only. Mean length of surgery was 157 ± 45 min. Eleven patients had 8 and 3 had 4 screws placed. In 2 patients radiotherapy was not completed due to bending of the guide canula with consecutive abortion of IORT. All other patients received 8 Gy isodoses at mdn. 1.5 cm [1.1–1.9, IQR] depth during 2-6 min. The patients had Epidural Spinal Cord Compression score 1a-3. Seven patients (46.7%) experienced adverse events including 2 surgical site infection (one 65 days after surgery).Conclusion50 kV photon IORT for SM and consecutive unstable spine needing surgical intervention is safe and feasible and can be a promising technique in selected cases.

Radiation Exposure During Lumbar Interbody Fusion Surgery Can Be Reduced by Using a Three-Dimensional Patient-Specific Template Guide.

The use of posterior lumber interbody fusion (PLIF) using cortical bone trajectory (CBT) with a patient-specific 3D template guide is increasingly widespread. To our knowledge, no studies have extensively evaluated the reduction of radiation exposure when using patient-specific drill template guides. The purpose of this study is to compare the intra-operative radiation dose and surgeon's exposure to radiation in CBT-PLIF when using a patient-specific drill guide with that in traditional minimally invasive (MIS)-PLIF. In this observational study, we retrospectively compared data from five patients who were treated with single-level CBT-PLIF using a patient-specific drill guide (G group) and five patients who were treated with single-level traditional MIS-PLIF (M group). We compared the surgical time, surgeon's exposure to radiation, and intra-operative radiation time and dose between the two groups of patients. The mean age of the patients was 67.0 years in the M group and 74.2 years in the G group. The average surgical time was 242.8 min in the M group and 189.6 min in the G group (p = 0.020). The surgeon's exposure to radiation was 373.7 µSv in the M group and 81.75 µSv in the G group at chest level outside the protector (p = 0.00092); 42.0 µSv (M group) and 3.6 µSv (G group) at chest level inside the protector (p = 0.0000062); and 4.33 µSv (M group) and 1.20 µSv (G group) at the buttocks of the surgeon (p = 0.0013). Radiation time was 269.8 s (M group) and 56.6 s (G group) (p = 0.0097), and radiation dose was 153.7 mGy (M group) and 30.42 mGy (G group) (p = 0.00057). The patient-specific drill template guide is an invaluable tool that facilitates the safe insertion of CBT screws with a low radiation dose from the outset.

Intraoperative Staff Radiation Exposure During Aortic Endovascular Procedures

The risk of radiation exposure in the surgical operating room (OR) and/or catheterization laboratory is now well established. Complex endovascular procedures often require multiple approaches and different positioning of the staff members around the patient, potentially increasing the levels of radiations exposure. Our goal was to evaluate the levels of radiation exposure of the members of the staff during endovascular aortic procedures in order to propose radioprotection optimization. We included 41 aortic endovascular procedures out of 114 procedures performed between January 12, 2014, and August 31, 2015, including 24 standard endovascular aortic aneurysm repair (EVAR), 7 EVAR with iliac branch (EVARib), 8 complex fenestrated/branched EVAR (F/B EVAR), and 2 thoracic EVAR (TEVAR). Procedures were performed in an OR equipped with a carbon fiber table and a mobile fluoroscopy C-arm. We collected the usual dosimetry data given by the C-arm as well as the patient's peak skin dose (PSD). In all staff members, radiation exposure was measured with thermoluminescent chip dosimeters placed on both temples, on posterior sides of both hands, and on both lower legs. PSD levels were low for EVAR because 24 patients had values below the reading threshold. PSD significantly increased with more complex procedures. Main operator (MO) received the higher level of irradiation on whole body, hands, and ankles. Eye lenses irradiation was higher on both assistant operators (AOs). Other members received low levels of irradiation. We found a high ranges of radiation exposure with a high risk of exposure for the AO, mainly for F/B EVAR and EVARib. Even if all personal protections are used, staff positioning is a major point that must be considered. If MO is supposed to be the most exposed to X-rays, specific conditions of positioning of the AO may be at risk of exposure.

Targeted Intraoperative Radiotherapy (TARGIT-IORT) in Breast Cancer Surgery

According to the WHO, breast cancer (BC) has become the largest increase cancer in the world. The vast majority of cancers require radiotherapy and it is the mainstream treatment modality. Although there are numerous treatments, it still does not have a suitable one because of the side effects of radiotherapy. To reduce the harm to the body, people are attending to find a fewer side-effect one. Nowadays, the intraoperative radiation therapy（IORT）is starting to come into its own. TARGIT-IORT is a type of accelerated partial breast irradiation (APBI). The differences between TARGIT-IORT and traditional radiation are the localized radiating space and radiotherapy can be administered during surgery. Researchers have now found that it has a precise radiation range and can be performed simultaneously during surgery. Besides, it performs even better than traditional radiation therapy in various aspects. This is certainly a new trend in breast cancer treatment. TARGIT-IORT is expected to be the next trend in the treatment of BC.

Clinical study of ear keloids with surgical excision and intraoperative low-energy X-ray irradiation therapy

Objective:To explore the clinical efficacy of surgical excision combined with low-energy X-ray irradiation in the treatment of ear keloids. Methods:Clinical data of 32 cases of ear keloid lesions that received surgical treatment alone or surgery combined with radiotherapy from March 2019 to November 2022 in the Department of Otorhinolaryngology Head and Neck Surgery of the Tianjin First Central Hospital were retrospectively analyzed. Among them, 10 cases received radiotherapy and 22 cases did not receive radiotherapy. The radiotherapy group received irradiation with a large divided dose of 50 kV low-energy X-rays. The mode of fractionation radiotherapy was as follows: the first was 10 Gy of intraoperative radiation therapy and the second was 8 Gy on the 3rd postoperative day for a total of 18 Gy. The local efficacy and skin radiation reaction were observed at a follow-up of 8-52 months. Results:The median follow-up was 26 months, and as of the date of the last follow-up, 9 cases were cured and 1 case was ineffective in the radiotherapy group, with an effective rate of 90.0%, while 9 cases were cured and 13 cases were ineffective in the no-radiotherapy group, with an effective rate of 40.9%. The recurrence of ear keloids was not related to the side, site, or etiology of the patient's onset（P>0.05）. Recurrence was related to whether or not the patients received radiotherapy（χ²=4.885, P<0.05）, and the recurrence rate in the radiotherapy group（10.0%） was significantly lower than that in the non-radiotherapy group（59.1%）. Conclusion:Surgical excision combined with low-energy X-ray irradiation therapy is an effective method of treating keloids in the ear, especially with intraoperative radiation therapy can achieve more satisfactory results.

118 Intraoperative Radiotherapy Combined With Spinal Stabilization Surgery. A Novel Treatment Strategy for Spinal Metastases. First Experiences at a Single Center

INTRODUCTION: Contemporary treatment of spinal metastases (SM) aims on preserving spinal stability, neurological status, local control and functional status. It consists of spinal surgery followed by radio- and chemotherapy. Adjuvant therapy is performed after several weeks to prevent wound healing issues. Intraoperative radiotherapy (ioRT) is a solution to shorten treatment time, successfully applied in brain tumor, breast and colorectal surgery but not SM to date. METHODS: Results on morbidity and mortality of ioRT combined with stabilization surgery in SM in a first single center series are described. Stabilization is performed as CT-navigated open or percutaneous procedure using a carbon screw-rod system followed by 50kV photon-ioRT using the ZEISS Intrabeam during a single session in prone position. The ioRT probe is placed through a guide canula via navigation and positioning is controlled by ioCT to enable RT isodose planning in the OR. Patient characteristics, perioperative specifications and postoperative follow up along with adverse events (AE) are reported. RESULTS: 11 (7 female) patients (69 ± 9.4y) received treatment from 07/22-04/23. Median SINS was 8 [7-10] IQR, with metastasis located in thoracic (n = 9) and lumbar (n = 2) spine. 6 patients receive open, 4 percutaneous stabilization and 1 decompression only. Mean length of surgery was 153±52 min. with 2 Patients receiving 4 and 8 patients receiving 8 screws respectively. In 2 Patients radiotherapy was not completed due to bending of the guide canula with consecutive security abortion of ioRT. All other patients received 8Gy isodoses during 2-6 min. Patients treated had ESCC 1a-2. Mean follow up was 63 ± 49 days. 4 patients experienced AEs including 1 case of fatal surgical site infection. CONCLUSIONS: 50 kV photon ioRT for SM can be a promising technique for selected cases of SM.

Patient-specific cutting guides in corrective osteotomy near to the knee joint

Patient-specific cutting guides (PSCG) are used in osteotomy near to the knee joint to simplify the operative technique, shorten the duration of surgery, reduce radiation exposure and to exactly realize the preoperative planning during surgery, especially when complex deformities are corrected simultaneously in multiple planes. The application of PSCG is in principle possible in all osteotomies near to the knee joint but is especially useful in multidimensional, complex osteotomy. No specific contraindications. After multidimensional 3D analysis and planning using apreoperative computed tomography (CT) protocol, a3D-printed patient-specific cutting guide is produced. This PSCG is used during standard osteotomy near to the knee. Using this PSCG the guided sawcut and predrilling of the screw positions inside the bone for the screws of the planned angle stable osteotomy plate are performed. The amount of the deformity correction needed is "stored" in the PSCG and is converted to the bony geometry during placement of the screws in the predrilled holes through the plate after opening or closing the osteotomy. Apart from that, the surgical approach and technique are equivalent to the standard osteotomy types near to the knee. The application of PSCG in osteotomy near to the knee does not change the postoperative management of the specific osteotomy. The use of patient-specific cutting guides leads to a higher accuracy in the implementation of the preoperative planning and the desired target axis is achieved with greater accuracy. Multidimensional complex corrections can also be exactly planned and implemented. In addition, the intraoperative radiation exposure for the operation team can possibly be reduced.