Treatment Volume Research Articles

Executive Summary of the American Radium Society Appropriate Use Criteria for Management of Squamous Cell Carcinoma of the Cervical Esophagus: Systematic Review and Guidelines.

Cervical esophageal cancer (CEC) is an uncommon malignancy accounting for <5% of all esophageal carcinomas. Treatment of CEC varies and is adapted from established regimens used for squamous cell carcinoma (SCC) or the lower esophageal and head and neck. The present systematic review and guidelines are intended to assist treatment decision making for patients with CEC based on the available evidence. Using the Population, Intervention, Comparator, Outcome, Timing, and Study Design (PICOTS) framework, the evidence regarding treatment outcomes was assessed using Cochrane and PRISMA 2020 methodology. Eligible studies included prospective Phase II to III trials and retrospective analyses published between January 1, 2013 and February 23, 2024 in the Ovid Medline database. These references were assessed through the American Radium Society (ARS) Appropriate Use Criteria (AUC) methodology. A systematic review PRISMA 2020 checklist confirmed the completion of essential elements. RAND-UCLA consensus methodology was used by the expert panel to rate the appropriateness of the treatment options. ARS AUC recommendations include (1) larynx preservation using endoscopic resection (EMR or ESD) alone for the typical case with pT1a cN0 cM0 CEC, (2) definitive CRT for the typical case with cT1bN0M0 in patients who cannot undergo endoscopic resection, (3) larynx-preserving using definitive CRT (with or without induction chemotherapy) for the typical case with nonmetastatic locally advanced CEC (advanced T-stage tumors or involved lymph nodes), with surgery reserved for those patients with incomplete response or locoregional recurrence. This ARS AUC summary provides guidelines for the management of SCC of the cervical esophagus provides based on available evidence. Topics that warrant further investigation include optimization of (1) patient selection; (2) multimodality therapies including chemotherapy, immunotherapy, and targeted agents; (3) radiation dose, schedule, and treatment volume; and (4) supportive care for patients with CEC. Ongoing trials continue to improve outcomes for patients with CEC.

Improving methodology of radiosurgery for posterior fossa cavernomas: higher volume, lower dose.

We conducted a prospective series involving 35 posterior fossa cavernomas in 33 patients treated with low-dose radiosurgery protocols (12 Gy in a single fraction or 18 Gy in 3 fractions). Compared to previously published series, our approach targeted a larger treatment volume, encompassing the entire hemosiderin ring surrounding the cavernoma. Radiosurgery was indicated for cases of hemorrhage or progressive neurological deficits in anatomically challenging, nonsurgical areas. The statistical analysis was designed to address the unknown onset time of cavernoma prior to radiosurgery, enabling a more accurate calculation of the hemorrhage incidence rate before treatment. Follow-up evaluations, including clinical assessments and MRI, were conducted at 3-6-9-12-18-24 months and subsequently on an annual basis. With a mean follow-up duration of 26 months, exceeding the previously described latency period, and a median [IQR] follow-up of 13 months [8.7-30.4] which represents approximately half the latency period, only one patient experienced a recurrence of hemorrhage, occurring 20 months post-treatment and remaining asymptomatic. No patients exhibited radio-induced parenchymal changes or clinical deterioration following radiosurgery. These preliminary results support the strategy of increasing the target volume while reducing the radiation dose for cavernous malformations. We further recommend incorporating sensitivity analyses to evaluate the robustness of results, particularly in the context of uncertainties surrounding the time of onset of cavernomas.

Respon Pertumbuhan Dan Produksi Tanaman Siomak (Lactuca Sativa L.) Pada Variasi Media Tanam Dan Pupuk Urin Kelinci

Siomak is a type of lettuce plant that has a slightly different leaf shape from lettuce plants in general. This research aims to determine the interaction between planting media treatment and rabbit urine fertilizer concentration on the growth and yield of siomak plants. This research was carried out from April to May 2022 in Rejomulyo Village, Kras District, Kediri Regency, East Java Province. This research used a factorial completely randomized design (CRD) with two factors. The first factor is the planting medium (M), while the second factor is the concentration of rabbit urine fertilizer (K). The results of this research show that the M2K4 treatment combination (planting media ratio 2:1:3 + 40 ml/L urine fertilizer) is the treatment combination with the best results in the observation variables of number of leaves and wet weight per plant. The combination of M2K2 treatment (planting media ratio 2:1:3 +20 ml/L urine fertilizer) is the combination with the best results in increasing the root length of siomak plants. The single treatment of M2 planting media (planting media ratio 2:1:3) showed better results than the results of treatment M1 (planting media ratio 2:1:2) significantly in the observation variables of plant height, number of leaves, leaf area and root volume. . K4 treatment (urine fertilizer 40 ml/L) is the most effective and efficient concentration in increasing plant height and leaf area growth. The results of observing the root volume of the K5 treatment (50 ml/L urine fertilizer) showed the best results.

Fractionated Reirradiation of Recurrent High-Grade Gliomas: Safety with Higher Reirradiation Dose and Larger Targets

Abstract Background The optimal regimen, normal tissue tolerances, and appropriate indications for reirradiation for recurrent high-grade glioma (HGG) are uncertain. The aim of this study was to determine whether higher reirradiation dose was associated with toxicity or survival. Methods Patients with HGG treated with fractionated reirradiation at a single institution from 2007-2022 were retrospectively reviewed. Metrics evaluated included overall survival (OS), prognostic factors for survival, and treatment-related toxicity. Results 230 patients with recurrent HGG were reviewed. Median follow-up was 8.8 months. Median reirradiation dose was 41.4 Gy with 80.4% receiving concurrent systemic therapy Median cumulative maximum doses to brainstem and optic structures were 77.9 Gy (range, 4.6 – 146.0 Gy) and 55.1 Gy (3.3 – 106.3 Gy), respectively. No injuries to these structures were identified. Radiation necrosis (RN) was identified in 9.4%. There were no significant associations between RN and target size, systemic therapy use, or reirradiation dose. Median OS was 10.2 months from reirradiation start. On multivariate analysis, improved OS was associated with better KPS, longer interval between radiotherapy sessions, reirradiation at first recurrence, and reirradiation dose ≥ 41.4 Gy. Median OS for those with IDH wildtype glioblastoma was 8.7 months. On multivariate analysis of an IDH wildtype disease subanalysis, improved OS was associated with longer interval between radiotherapy sessions and higher reirradiation dose. Conclusions These data support the safety and efficacy of fractionated reirradiation for recurrent HGG. They suggest higher reirradiation dose may be feasible, including for large treatment volumes and for tumors near the brainstem or optic structures.

Separation Surgery Followed by Conformal Postoperative Spine Stereotactic Body Radiation Therapy Does Not Increase Risk of Adjacent Spine Level Progression in the Management of Spine Metastases.

To determine if piecemeal separation surgery, in conjunction with smaller treatment volumes utilized with spine stereotactic radiation therapy (S-SBRT), increased the risk of adjacent level progression (ALP). We performed a retrospective analysis of a prospectively maintained database of adult spine oncologic patients who underwent SBRT to the spine at University of Michigan from 2010 to 2021. We compared ALP in patients undergoing SBRT who had pretreatment surgery with those who did not. Four hundred and ninety-eight treatment sites were identified in 417 patients. Of these, 366 (73.5%) were treated with SBRT alone and 132 (26.5%) were treated with surgery followed by S-SBRT. Patients treated with SBRT alone were significantly older (63.3y) compared with the surgery plus SBRT group (60.2y; P=0.02). More radiosensitive histologies were treated with SBRT alone (34%) compared with 11% for the surgery plus SBRT group (P<0.001). Lesions treated in the surgery plus SBRT group had significantly more severe metastatic epidural spinal cord compression (65%) compared with the SBRT only group (8%) (P<0.001). Both infield progression (9.3% vs. 7.6%; P=0.43) and ALP (21.3% vs. 18.9%; P=0.37) were not significantly different between groups. Spine oncology patients treated with surgery followed by conformal postoperative S-SBRT had similar infield and ALP compared with patients receiving SBRT alone, suggesting that piecemeal separation surgery does not locally spread tumor cells, leading to an increased risk of ALP failure, and supporting the use of conformal postoperative S-SBRT.

NNFit: A Self-Supervised Deep Learning Method for Accelerated Quantification of High- Resolution Short Echo Time MR Spectroscopy Datasets.

"Just Accepted" papers have undergone full peer review and have been accepted for publication in Radiology: Artificial Intelligence. This article will undergo copyediting, layout, and proof review before it is published in its final version. Please note that during production of the final copyedited article, errors may be discovered which could affect the content. Purpose To develop and evaluate the performance of NNFit, a self-supervised deep-learning method for quantification of high-resolution short echo-time (TE) echo-planar spectroscopic imaging (EPSI) datasets, with the goal of addressing the computational bottleneck of conventional spectral quantification methods in the clinical workflow. Materials and Methods This retrospective study included 89 short-TE whole-brain EPSI/GRAPPA scans from clinical trials for glioblastoma (Trial 1, May 2014-October 2018) and major-depressive-disorder (Trial 2, 2022- 2023). The training dataset included 685k spectra from 20 participants (60 scans) in Trial 1. The testing-dataset included 115k spectra from 5 participants (13 scans) in Trial 1 and 145k spectra from 7 participants (16 scans) in Trial 2. A comparative analysis was performed between NNFit and a widely used parametric-modeling spectral quantitation method (FITT). Metabolite maps generated by each method were compared using the structural- similarity-index-measure (SSIM) and linear-correlation-coefficient (R2). Radiation treatment volumes for glioblastoma based on the metabolite maps were compared with the Dice-coefficient and a two-tailed t test. Results Average SSIM and R2 scores for Trial 1 test set data were 0.91/0.90 (choline), 0.93/0.93 (creatine), 0.93/0.93 (n-acetylaspartate), 0.80/0.72 (myo-inositol), and 0.59/0.47 (glutamate + glutamine). Average scores for Trial 2 test set data were 0.95/0.95, 0.98/0.97, 0.98/0.98, 0.92/0.92, and 0.79/0.81 respectively. The treatment volumes had average Dice coefficient of 0.92. NNFit's average processing time was 90.1 seconds, whereas FITT took 52.9 minutes on average. Conclusion This study demonstrates that a deep learning approach to spectral quantitation offers comparable performance to conventional quantification methods for EPSI data, but with faster processing at short-TE. ©RSNA, 2025.

PET/CT-based target volume definition in involved-site radiotherapy for treatment of early-stage nodal follicular lymphoma.

Recent advancements in imaging, particularly 18F-fluorodeoxyglucose positron-emission tomography-computed tomography (FDG-PET/CT), have improved the detection of involved lymph nodes, thus influencing staging accuracy and potentially treatment outcomes. This study is apost hoc analysis of the GAZAI trial data to evaluate the impact of FDG-PET/CT versus computed tomography (CT) alone on radiation target volumes for involved-site radiotherapy (IS-RT) in early-stage follicular lymphoma (FL). All patients in the GAZAI trial underwent pretherapeutic FDG-PET/CT examinations, which were subject to central quality control. Lymph nodes with pathological metabolism were assessed for CT morphology. Differential regional involvement and the impact on radiation target volume for IS-RT were compared between PET/CT-based to solely CT-based staging. In 54patients with PET-positive lymph nodes after initial surgery, 170 involved lymph nodes were identified in total. FDG-PET/CT identified additionally involved lymph nodes not detected by CT in 61% of the patients, leading to asignificant change in radiation treatment fields for 30% of the cohort. Only 58% of all involved lymph nodes exhibited pathological CT morphology. The findings were robust across different Deauville score thresholds and CT morphological metrics. The findings confirm the essential role of FDG-PET/CT in accurately defining the radiation volume for treatment of early-stage follicular lymphomas with radiotherapy. These results support the integration of FDG-PET/CT into the standard diagnostic pathway and its inclusion in the service catalogue of statutory health insurance, emphasizing its importance for optimal treatment planning and the potential impact on patient outcomes.

Key Problems and Strategies for Greenhouse Gas Reduction in China's Wastewater Treatment Industry

The wastewater treatment industry is an energy-intensive industry and one of the main sources of high warming potential greenhouse gases （GHG） such as CH4 and N2O. The GHG reduction in this industry is an important part of achieving global climate goals. In 2019, there were 4 359 urban wastewater treatment plants in China, with a total wastewater treatment volume of 63.26 billion m3, ranking first in scale worldwide. From 2009 to 2019, the energy consumption, GHG emissions, and GHG emissions intensity of wastewater treatment in China increased by 161.78%, 193.55%, and 41.54%, respectively. Faced with the new situation, new tasks, and new requirements of the collaborative promotion of carbon reduction, pollution reduction, green expansion, and growth, water pollutant reduction needs to be coordinated with GHG reduction. To this end, the sources and trends of energy consumption and GHG emissions in the wastewater treatment industry were identified, and the situation and challenges to GHG reduction in this industry were analyzed. The results indicated that the wastewater treatment industry in China has been facing problems such as a lack of carbon emission-related standards, insufficient energy self-sufficient technology reserves, lack of coordination between wastewater treatment levels and carbon emissions control, and inadequate infrastructure and operation and maintenance management. Based on this, it is necessary to accelerate the top-level design of GHG reduction in the wastewater treatment industry； strengthen the research and development, verification, demonstration, and integrated application of disruptive technologies； expand the natural-based solution as a technological supplement； innovate refined management in the wastewater treatment industry； and ultimately promote the reconstruction of the wastewater treatment industry.

In-Depth Conformance Treatment in Fractured Carbonate Reservoirs: From Laboratory Evaluation to Field Application

Summary Gel treatment has been widely applied to reduce water production by blocking the water thief zones and improve oil recovery. However, the presence of fractures makes the gel treatment more challenging. The BTLW oil field is a carbonate reservoir characterized with low-angle fractures, resulting in significant water channeling. The tracers injected into the production wells from the injection well often exhibit a rapid breakthrough time of less than 2 days, suggesting a direct connection between the injection and production points. Based on laboratory study, the polymer gel system and microgel were designed for in-depth conformance control treatment in field BTLW. The in-depth gel conformance treatment commenced in June 2019, where a mixture of multiple plugs (polymer-polymer gel-microgel) was injected into six treatment wells. The polymer gel was used to block the fractures and high influx channeling. The microgel was designed to further divert in-depth fluid from the high-permeability zone into lower permeability. The chemical treatment volume for each well, determined by the tracer test, varies from 18 000 m3 to 35 000 m3. The volume of the microgel treatment is designed to be the entire volume of the tracer that is swept through. The combination treatment demonstrated a significant increase in efficiency in both production wells and injection treatment wells. The interwell tracer tests revealed a delayed occurrence of tracer breakthrough at the production wells, with the water being redirected into zones with lower permeability. Besides, the injectivity behavior was significantly reduced in the injection wells. The Hall plot showed a steeper hall slope during each well treatment, implying a positive change in skin. The water injectivity index also reduced after conformance treatment, which indicated the alteration in permeability and improvement in reservoir conformance. The results indicated an increase in the oil production rate and a decrease in the water cut following the treatment. As of June 2024, the incremental oil was estimated to be approximately 84 834 tonnes in total via decline curve analysis, and each metric ton of polymer injection can enhance oil production by 875 metric tons.

Safety and efficacy of histotripsy delivery through overlying gas-filled small bowel in an ex vivo swine model

Purpose To evaluate the safety and efficacy of performing histotripsy through overlying gas-filled bowel in an ex vivo swine model. Methods An ex vivo model was created to simulate histotripsy treatment of solid organs through gas-filled bowel. Spherical 2.5 cm histotripsy treatments were performed in agar phantoms for each of five treatment groups: 1) control with no overlying bowel (n = 6), 2) bowel 0 cm above phantom (n = 6), 3) bowel 1 cm above phantom (n = 6), 4) bowel 2 cm above phantom (n = 6), and 5) bowel 0 cm above the phantom with increased treatment amplitude (n = 6). Bowel was inspected for gross and microscopic damage, and treatment zones were measured. A ray-tracing simulation estimated the percentage of therapeutic beam path blockage by bowel in each scenario. Results All histotripsy treatments through partial blockage were successful (24/24). No visible or microscopic damage was observed to intervening bowel. Partial blockage resulted in a small increase in treatment volume compared to controls (p = 0.002 and p = 0.036 for groups with bowel 0 cm above the phantom, p > 0.3 for bowel 1 cm and 2 cm above the phantom). Gas-filled bowel was estimated to have blocked 49.6%, 35.0%, and 27.3% of the therapeutic beam at 0, 1, and 2 cm, respectively. Conclusion Histotripsy has the potential to be applied through partial gas blockage of the therapeutic beam path, as shown by this ex vivo small bowel model. Further work in an in vivo survival model appears indicated.

Bulgarian Experience in Vaginal Electronic Brachytherapy for Gynecologic Cancers' Treatment-First Results.

Background/Objectives: The objective of this study is to prospectively collect dosimetric and clinical data on vaginal cuff electronic brachytherapy and propose a protocol for the procedure. Methods: Twenty-five patients who had proven endometrial or cervical carcinoma and had undergone radical hysterectomy have been treated with vaginal cuff electronic brachytherapy. Treatment session durations and doses to the targets and the organs at risk have been extracted from the treatment planning software. Patients have been followed up for early side effects for 3 months. Results: Treatment session times ranged from 3.0 to 6.6 min. Mean coverage of the planned treatment volume with 100% of the prescribed dose was 90%, and with 95% of the prescribed dose was 95%. Doses in the bladder were lower than those achieved in previously published studies with a mean D2cc of 4.7 Gy, and doses in the rectum were higher with a mean D2cc of 5.3 Gy. The first-month adverse events included eight G1 and three G2 toxicities, while the events registered on the third month were two G2 vaginal dryness events and one G1 urinary tract obstruction, of which only one patient with vaginal dryness did not respond to local treatment. No local relapses have been detected. Conclusions: Vaginal cuff electronic brachytherapy has demonstrated safety and effectiveness.

Radiotherapy for Rectal Cancer and Radiation-Induced Malignancies from Epidemiological and Dosimetric Data

Preoperative or postoperative radiation therapy is broadly employed in patients with rectal carcinoma. Radiotherapy directs high-energy beams of ionizing radiation toward the tumor area to destroy cancer cells. High radiation doses are needed for cell killing. The radiation exposure of the healthy tissues/organs may lead to carcinogenesis. This study describes the evolving role of radiotherapy in rectal cancer management. The present report also reviews epidemiological and dosimetric studies related to the radiation-induced second malignancies from pelvic radiotherapy. Some epidemiological studies have concluded that the second-cancer risk in patients subjected to radiation therapy does not increase compared to unexposed rectal cancer patients. Other researchers found an elevated or a marginally increased probability for second-cancer induction. Dosimetric studies reported cancer risk estimates for critical organs or tissues in the near and far periphery of the treatment volume. Useful information about the effect of the treatment parameters such as the irradiation technique, photon beam energy, and fractionation schedule on the organ-specific second-cancer risk was derived from the dose data analysis. The knowledge of these effects is needed for the selection of the optimal treatment parameters enabling a reduction in the resultant risk of carcinogenesis.

Partial or Focal Brachytherapy for Prostate Cancer: A Systematic Review and Meta-Analysis.

Recent advances in image-guided brachytherapy have allowed for treatment volume reduction in the treatment of prostate cancer, with the aim to optimize disease control and reduce toxicities. This systematic review reports on the efficacy and safety of focal brachytherapy for treatment of patients with localized prostate cancer. Medline, Embase, Web of Science and Cochrane were searched from inception to July 2023. Studies were included if they reported on focal brachytherapy, and described either dosimetry or clinical outcomes in the monotherapy or salvage setting. Meta-analysis was conducted to estimate biochemical control (BC) at 12-60 months. The review protocol was registered on PROSPERO (CRD42022320921). 26 studies reporting on 1492 patients were included in this review. 14 studies reported on monotherapy, 10 on salvage and 2 on boost. The majority of studies used MRI and/or biopsy or PET for target identification, and MRI fusion and transrectal ultrasound (TRUS) for image guidance technique. BC for monotherapy was 97% (95%CI: 86-99%) at 24 months, and 82% (95%CI: 65-92%) at 60 months. BC for salvage was 67% (95%CI: 62-72%) at 24 months, and 35% (95%CI: 17-58%) at 60 months. Low rates of toxicity were reported across studies. Focal brachytherapy has promising efficacy and safety profiles. Future studies may compare focal brachytherapy to whole-gland treatments, to investigate relative efficacy and safety. In well-selected patients, partial or focal brachytherapy represents an evidence-based option with acceptable BC rates and a favourable toxicity profile.

Search for clinical, genetic, morphological and immunohistochemical predictors of parathyroid cancer recurrence

Background. Currently, there is no consensus on postoperative risk stratification for parathyroid cancer (PC). The risk factors of disease progression are crucial for choosing the optimal treatment strategy, including adjuvant methods and patient,s follow-up. Aim. Identifying predictors of PC recurrence Materials and methods. We performed a retrospective observational study of 85 patients with verified PC divided into remission (n=61) and recurrence (n=19) groups after primary surgical treatment for the period 2004–2023. The analyzed parameters included demographic, laboratory and instrumental data of patients with PC, the presence of a mutation in the CDC73 gene, morphological and immunohistochemical characteristics of the primary tumor. Results. After adjustments for multiple comparisons, a statistically significant association of recurrence was found for preoperative calcium level (p0.001), pT4 stage (p0.001) according to TNM-classification (Tumor, Nodus, Metastasis) American Joint Committee on Cancer 2017. There was a statistical trend for calcium correction for hypoalbuminemia (p=0.002), presence of nephrolithiasis/nephrocalcinosis (p=0.021), parathyroid hormone level 6 months after primary surgery (p0.05), pT3 stage TNM (p=0.007), nuclear expression of parafibromin in tumor tissue (p0.05). We did not reveal any associations between disease recurrence and sex, age, volume of surgical treatment, germline mutation in the CDC73, parafibromin expression and Ki-67 in tumor tissue. Conclusion. Our study revealed several factors of poor prognosis, allowing to identify a risk group for recurrence, which can contribute to active dynamic monitoring and timely treatment.

Pre-pilot forward osmosis – Membrane distillation hybrid system for sustainable produced water treatment and reducing volume of hazardous waste in oil and gas industry

This study introduces pre-pilot scale hybrid forward osmosis - membrane distillation (FO-MD) module, designed for the simultaneous treatment of different challenging produced water (PW) streams from Oil &Gas Industry. In this module, hot draw solution simultaneously serves as MD feed solution. The performance of this module was assessed with synthetic and real PW streams for extended operating times. The MD permeate production was doubled and comprised 0.4 L/h for 7:1 MD/FO area ratio (0.105 m2 and 0.015 m2, respectively) compared to permeate production that was observed with equal MD and FO membrane area (0.015 m2 each). The conductivity of the final product water was 364.9 ± 2.7 μS/cm, comparable to the typical potable water conductivity, implying its potential for reuse applications and minimizing volume of hazardous waste. Analysis of MD permeate quality showed that concentration of major ions was reduced by >99 % and chemical oxygen demand was removed by 90.1 %. Continuous operation with real produced streams led to partial pore wetting on the MD active layer. The microscopy showed organic fouling caused by oil and grease deposition and NaCl/CaSO4 scaling was found on both sides of FO membrane. These results suggest that PW pretreatment should be implemented to alleviate membrane fouling and pore wetting. We also observed reverse solute flux of 7.07 g/m2 h in experiments utilizing real DE and WO streams. The results of this study helped to identify challenges arising from the system scale-up and provide grounds for integrating hybrid FO-MD technology to recover water from oil and gas facilities.

Development of a protocol for whole-lung in vivo lung perfusion-assisted photodynamic therapy using a porcine model.

Standard treatments for isolated lung metastases remain a clinical challenge. In vivo lung perfusion technique provides flexibility to overcome the limitations of photodynamic therapy (PDT) by replacing the blood with acellular perfusate, allowing greater light penetration. Using Monte Carlo-based simulations, we will evaluate the abilities of a light delivery system to irradiate the lung homogenously. Afterward, we aim to demonstrate the feasibility and safety profile of a whole-lung perfusion-assisted PDT protocol using 5-ALA and Chlorin e6. A porcine model of a simplified lung perfusion procedure was used. PDT was performed at 630 or 660nm with 5-ALA or Chlorin e6, respectively. Light fluence rate measurements and computed tomography (CT) scan segmentations were used to create in silico models of light propagation. Physiologic, gross, CT, and histological assessment of lung toxicity was performed 72h post-PDT. Dose-volume histograms showed homogeneity of light intensity throughout the lung. Predicted and measured fluence rates showed strong reliability. The photodynamic threshold of 5-ALA was , whereas Chlorin e6 showed negligible uptake in lung tissue. We lay the groundwork for personalized preoperative in silico dosimetry planning to achieve desired treatment volumes within the therapeutic range. Chlorin e6 demonstrated the greatest therapeutic potential, with a minimal uptake in healthy lung tissues.

Application of Machine Learning to Predict the Capacity of Fractured Horizontal Wells in Shale Reservoirs

Shale oil wells typically have numerous volume fracturing segments in their horizontal sections, resulting in significant variability in productivity across these segments. Conventional productivity prediction and fracturing effect evaluation methods are challenging to apply effectively. Establishing a stable and efficient intelligent productivity prediction method using machine learning is a promising approach for the effective development of shale oil reservoirs. This study is based on geological data, fracturing records, and a production database of 91 production wells in a shale oil reservoir in a specific area. Fourteen key parameters affecting productivity were selected from geological and engineering perspectives, and the recursive feature elimination method based on support vector machines identified five optimal main controlling factors. Three machine learning methods—decision tree, random forest, and gradient boosting decision tree (GBDT)—were used to model productivity prediction, with root mean square error (RMSE) employed to evaluate model performance. The study results indicate that formation coefficient, cluster spacing, treatment volume, sand volume, and fracturing segment length are the main controlling factors influencing productivity in fractured horizontal wells. Among the models, the random forest algorithm with bootstrap sampling produced the most stable prediction results, achieving a prediction accuracy of 94% and an RMSE of 0.934 on the test set, outperforming the decision tree and GBDT models in terms of minimum RMSE on the test set.

Residual cholesteatoma of the temporal bone in a patient with granulomatosis with polyangiitis

A case of residual temporal bone cholesteatoma in a patient with granulomatosis with polyangiitis (Wegener) (GPA) is presented. At the onset of the disease, the patient developed a symptom complex, which included, along with sinonasal manifestations, left-sided purulent otitis media, refractory to traditional therapy. A separate atticoanthrotomy on the left temporal bone, performed in the active phase, before the diagnosis of vasculitis, did not lead to a clinical improvement in the condition of the middle ear. Despite the subsequent implementation of adequate immunosuppressive therapy and drug remission of GPA, the continuously recurrent course of purulent otitis media of the operated ear contributed to the development of residual cholesteatoma of the temporal bone with the spread of the process to surrounding structures. The presence of cholesteatoma was confirmed by MRI of the temporal bones in the non-EPI DWI mode. During the period of drug remission of GPA, repeated sanitizing surgery was performed on the middle ear with tympanoplasty and obliteration of the parathympanic spaces, which made it possible to achieve remission of purulent otitis media. The development of residual middle ear cholesteatoma in a patient with GPA could be due to the untimely initial diagnosis, the late onset of specific immunotherapy, the rapidly progressive and recurrent nature of the course of the disease, and surgical treatment in the phase of high disease activity. The insufficient volume of primary surgical treatment contributed to the formation of laced cavities and the development of residual cholesteatoma of the temporal bone. The use of MRI in the non-EPI DWI mode for diagnosis made it possible to identify the development of cholesteatoma of the left temporal bone in a patient with GPA and track the results of surgical treatment in the postoperative period. The non-EPI DWI MRI method proved effective both for detecting temporal bone cholesteatoma and tracking changes in the postoperative period of a patient with GPA. Tympanoplasty with surgical obliteration of the parathympanic spaces allowed to stop the inflammation of the middle ear in a patient with a systemic autoimmune disease.

RADT-17. FRACTIONATED REIRRADIATION OF RECURRENT IDH WILDTYPE GLIOBLASTOMA: HIGHER REIRRADIAITON DOSE AND SAFETY

Abstract The optimal regimen, normal tissue tolerances, and appropriate indications for reirradiation for recurrent glioblastoma (GBM) are uncertain. We evaluate outcomes and toxicity after fractionated reirradiation. Patients with recurrent IDH wildtype GBM after prior standard radiotherapy during 2007-2022 were retrospectively reviewed. All patients initially received conventionally fractionated radiotherapy. Radiation necrosis (RN) was determined by imaging or pathology. Overall survival (OS) was estimated using Kaplan-Meier methodology. Univariate and multivariate Cox proportional hazard models for OS were constructed. Bivariable associations with RN were estimated using fisher exact tests. 99 patients (median age 56 yrs, median KPS 80) were treated with reirradiation (median followup 7.4 mo). Median time between initial and reirradiation was 20 months (range, 2 – 214 mo). Median received dose at reirradiation was 41.4 Gy (30.6 – 60 Gy) to a median planning target volume (PTV) of 183 cc (16 – 825 cc). Median cumulative maximum dose to the optics and brainstem were 54 Gy (4 – 103 Gy) and 76 Gy (5 – 146 Gy), respectively. Median OS was 9 mo (95% CI 6.2 – 10.6 mo). On univariate analysis, time between initial and reirradiation ≥24 mo (HR 0.58, CI 0.36 – 0.94) and reirradiation dose ≥41.4 Gy (HR 0.56, CI 0.35 – 0.88) were associated with longer OS. On multivariate analysis, interval between radiation sessions (HR 0.56, CI 0.34 – 0.91) and higher reirradiation dose (HR 0.55, CI 0.35 – 0.87) remained associated with OS. No cases of radiation injury to the optics or brainstem were reported. 10% of patients experienced RN. Reirradiation dose ≥41.4 Gy, reirradiation PTV ≥200 cc and interval between radiation sessions &amp;lt; 24 mo were not significantly associated with RN. These data support the safety and efficacy of fractionated reirradiation for recurrent GBM including for large tumors. This study suggests that higher reirradiation dose may be feasible, including for large treatment volumes.

RADT-40. EVALUATION OF SMALLER CLINICAL TARGET VOLUMES AND PATTERNS OF PROGRESSION IN PATIENTS WITH NEWLY DIAGNOSED GLIOBLASTOMA TO INFORM FUTURE DIRECTIONS IN RADIATION TREATMENT PLANNING

Abstract BACKGROUND NRG Oncology Group guidelines recommend a clinical target volume (CTV) including generous expansions and incorporation of T2/FLAIR to account for potential tumor infiltration for glioblastoma patients, though smaller CTV expansions may be feasible. We retrospectively reviewed a large cohort of GBM patients to characterize patterns of recurrence and to assess the potential for smaller CTV margins. METHODS 312 consecutive adult patients with histologically confirmed diagnosis of glioblastoma treated with radiation therapy and temozolomide at a single institution were included in this study. All relevant clinical and pathological data was retrieved from local electronic medical records. MRIs from four timepoints 1) Pre-operative, 2) post-operative, 3) post-radiation and 4) time of progression were reviewed and fused with each other with rigid registration. We created a gross tumor volume including the resection cavity and residual enhancing tumor (GTV-GAD) and a GTV which included the GAD-GTV and pre-radiation T2/FLAIR signal (GTV-FLAIR). Multiple CTV expansions were applied to the GAD-GTV and FLAIR-GTV to evaluate coverage of subsequent progressive disease. RESULTS We evaluated 312 patients with a median age of 59.8 (range 20-93), 59% male, 61% KPS ≥ 90, 49% underwent gross total resection (51% subtotal resection/biopsy), 43% methylated and 57% unmethylated. CTV expansions of 2 cm, 1.5 cm, 1 cm, 0.5 cm, and 0 cm from GTV-GAD would have covered the epicenter of recurrent tumor in 90.7%, 88.1%, 84.6%, 77.5%, and 53.5% of cases respectively. CTV expansions from GTV-FLAIR of 2 cm, 1.5 cm, 1 cm, 0.5 cm, and 0 cm would have covered the epicenter of recurrent tumor in 93.5%, 92.6%, 91.3%, 88.1%, and 78.8% of cases respectively. On multivariable analysis, GAD-GTV and FLAIR-GTV volume were not associated with progression-free or overall survival(P&amp;gt;0.05). CONCLUSION Based upon our analysis, smaller treatment volumes could represent an opportunity to reduce treatment-related morbidity without compromising clinical outcomes.