Image-guided Treatment Research Articles

Clinical assessment of a low-cost, hand-held, smartphone-attached intraoral imaging probe for 5-aminolevulinic acid photodynamic therapy monitoring and guidance.

India has one of the highest rates of oral squamous cell carcinoma (OSCC) in the world, with an incidence of 15 per 100,000 and more than 70,000 deaths per year. The problem is exacerbated by a lack of medical infrastructure and routine screening, especially in rural areas. New technologies for oral cancer detection and timely treatment at the point of care are urgently needed. Our study aimed to use a hand-held smartphone-coupled intraoral imaging device, previously investigated for autofluorescence (auto-FL) diagnostics adapted here for treatment guidance and monitoring photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) fluorescence (FL). A total of 12 patients with 14 buccal mucosal lesions having moderately/well-differentiated micro-invasive OSCC lesions ( diameter and depth) were systemically (in oral solution) administered three doses of ALA (total ). Lesion site PpIX and auto-FL were imaged using the multichannel FL and polarized white-light oral cancer imaging probe before/after ALA administration and after light delivery (fractionated, total of 635nm red LED light). The handheld device was conducive for access to lesion site images in the oral cavity. Segmentation of ratiometric images in which PpIX FL is mapped relative to auto-FL enabled improved demarcation of lesion boundaries relative to PpIX alone. A relative FL (-value) threshold of 1.4 was found to segment lesion site PpIX production among the patients with mild to severe dysplasia malignancy. The segmented lesion size is well correlated with ultrasound findings. Lesions for which -value was at the time of treatment were associated with successful outcomes. These results indicate the utility of a low-cost, handheld intraoral imaging probe for image-guided PDT and treatment monitoring while also laying the groundwork for an integrated approach, combining cancer screening and treatment with the same hardware.

Near-infrared-IIb fluorescent nanozymes for imaging-guided treatment of traumatic brain injury

Traumatic brain injury (TBI) often results in damage to the blood–brain barrier (BBB), leading to secondary effects such as neuroinflammation mediated by reactive oxygen species (ROS), which can increase the risk of long-term neurological dysfunction. Therefore, it is crucial to remove excessive ROS and monitor the status of BBB for timely clinical intervention. Here, we developed a fluorescent nanozyme by doping Mn atoms into PbS/CdS quantum dots (QDs) that emit in the near-infrared-II (NIR-IIb, 1500–1700 nm) region, enabling imaging-guided treatment of TBI. The QD-based nanozyme exhibited excellent antioxidant activity due to uniformly distributed Mn atoms on the surface, which effectively scavenged ROS and inhibited the release of pro-inflammatory factors, thus providing neuroprotective effects for TBI treatment. Additionally, the nanozyme demonstrated exceptional NIR-IIb fluorescence performance, allowing for dynamic monitoring of BBB status with high spatiotemporal resolution to guide precise TBI treatment.

Image-guided permanent I-125 seed implantation for refractory head-and-neck carcinoma in China: A comprehensive review of contemporary technical and clinical aspects

Permanent I-125 seed implantation is one of the most commonly used brachytherapy (BT) forms, potentially applicable to almost any solid tumor as a standalone anti-tumor therapy or in combination with external beam radiotherapy (EBRT). The main advantage of I-125 seed implantation BT is its ability to deliver a high radiation dose within target volumes while maintaining a sharp dose drop-off profile, thereby protecting adjacent normal tissue. The clinical use of I-125 seed implantation in China has significantly increased in the past decades due to the application of an image-guided BT treatment planning system with reverse optimization capabilities and 3D printing individual template (3D-PIT) assistance. Computed tomography-guided I-125 seed implantation became a widely common modality of BT and has been used in many clinical settings for a variety of refractory cancer in China since 2002. The application has been expanded significantly not only for prostate cancer as monotherapy but also in combination with EBRT for the salvage treatment for refractory/recurrent head-and-neck carcinoma (HNC). With the assistance of 3D-PIT, since 2015, the quality control of I-125 seed implantation has been significantly adapted with high precision and real-time dose optimization. This review aims to summarize the developments and status of 3D-PIT-based I-125 seed implantation BT for the treatment of refractory HNC and standardized workflow in China.

A multimodal imaging-based classification for pediatric diffuse intrinsic pontine gliomas.

Pediatric diffuse intrinsic pontine glioma (DIPG) is a radiologically heterogeneous disease entity, here we aim to establish a multimodal imaging-based radiological classification and evaluate the outcome of different treatment strategies under this classification frame. This retrospective study included 103 children diagnosed with DIPGs between January 2015 and August 2018 in Beijing Tiantan Hospital (Beijing, China). Multimodal radiological characteristics, including conventional magnetic resonance imaging (MRI), diffuse tensor imaging/diffuse tensor tractography (DTI/DTT), and positron emission tomography (PET) were reviewed to construct the classification. The outcome of different treatment strategies was compared in each DIPG subgroup using Kaplan-Meier method (log-rank test) to determine the optimal treatment for specific DIPGs. Four radiological DIPG types were identified: Type A ("homocentric", n=13), Type B ("ventral", n=41), Type C ("eccentric", n=37), and Type D ("dorsal", n=12). Their treatment modalities were grouped as observation (43.7%), cytoreductive surgery (CRS) plus radiotherapy (RT) (24.3%), RT alone (11.7%), and CRS alone (20.4%). CRS+RT mainly fell into type C (29.7%), followed by type B1 (21.9%) and type D (50%). Overall, CRS+RT exhibited a potential survival advantage compared to RT alone, which was more pronounced in specific type, but this did not reach statistical significance, due to limited sample size and unbalanced distribution. We proposed a multimodality imaging-based radiological classification for pediatric DIPG, which was useful for selecting optimal treatment strategies, especially for identifying candidates who may benefit from CRS plus RT. This classification opened a window into image-guided integrated treatment for pediatric DIPG.

CT-guided local ablative interventions

Applicator-based local ablations under computed tomography (CT) guidance for the treatment of malignant tumors have found their way into clinical routine. The basic principles of the different ablation technologies and their specific clinical field of application are described. Acomprehensive literature review regarding applicator-based ablation techniques was carried out. Radiofrequency (RFA) and microwave ablation (MWA) represent two image-guided hyperthermal treatment modalities that have been established for the treatment of primary and secondary liver malignancies. In addition, both techniques are also applied for local ablative therapy of lung- and kidney tumors. Cryoablation is mainly used for the local ablation of T1 kidney cancer and due to its intrinsic analgetic characteristics for application in the musculoskeletal system. Nonresectable pancreatic tumors and centrally located liver malignancies can be treated with irreversible electroporation. This nonthermal ablation modality preserves the structure of the extracellular matrix including blood vessels and ducts. Technical advancements in the field of CT-guided interventions include the use of robotics, different tracking and navigation technologies and the use of augmented reality with the goal to achieve higher precision, shorter intervention time and thereby reduce radiation exposure. Percutaneous ablation techniques under CT guidance are an essential part of interventional radiology and they are suited for local treatment of malignancies in most organ systems.

From Nano to Macro: An overview of the IEEE Bio Image and Signal Processing Technical Committee

The Bio Image and Signal Processing (BISP) Technical Committee (TC) of the IEEE Signal Processing Society (SPS) promotes activities within the broad technical field of biomedical image and signal processing. Areas of interest include medical and biological imaging, digital pathology, molecular imaging, microscopy, and associated computational imaging, image analysis, and image-guided treatment, alongside physiological signal processing, computational biology, and bioinformatics.

Anatomical study of the medial calcaneal nerve using high-resolution ultrasound.

To determine whether high-resolution ultrasound (US) can identify the course and relations of the medial calcaneal nerve (MCN). This investigation was initially undertaken in eight cadaveric specimens and followed by a high-resolution US study in 20 healthy adult volunteers (40 nerves) by two musculoskeletal radiologists in consensus. The location and course of the MCN as well as its relationship to adjacent anatomical structures were evaluated. The MCN was consistently identified by US along its entire course. The mean cross-sectional area of the nerve was 1 mm2 (range 0.5-2). The level at which the MCN branched from the tibial nerve was variable, located a mean of 7mm (range - 7-60) proximal to the tip of the medial malleolus. At the level of the medial retromalleolar fossa, the MCN was located inside the proximal tarsal tunnel a mean of 8mm (range 0-16) posterior to the medial malleolus. More distally, the nerve was depicted in the subcutaneous tissue at the surface of the abductor hallucis fascia with a mean direct distance to the fascia of 1.5mm (range 0.4-2.8). High-resolution US can identify the MCN at the level of the medial retromalleolar fossa, as well as more distally in the subcutaneous tissue at the surface of the abductor hallucis fascia. In the setting of heel pain, precise sonographic mapping of the MCN course may enable the radiologist to make diagnosis of nerve compression or neuroma, and perform selective US-guided treatments. In the setting of heel pain, sonography is an attractive tool for diagnosing compression neuropathy or neuroma of the medial calcaneal nerve, and enables the radiologist to perform selective image-guided treatments such as diagnostic blocks and injections. • The MCN is a small cutaneous nerve which rises from the tibial nerve in the medial retromalleolar fossa to the medial side of the heel. • The MCN can be depicted by high-resolution ultrasound along its entire course. • In the setting of heel pain, precise sonographic mapping of the MCN course may enable the radiologist to make diagnosis of neuroma or nerve entrapment, and perform selective ultrasound-guided treatments such as steroid injection or tarsal tunnel release.

Mild photothermal/radiation therapy potentiates ferroptosis effect for ablation of breast cancer via MRI/PA imaging guided all-in-one strategy

BackgroundNanotheranostics advances anticancer management by providing therapeutic and diagnostic functions, that combine programmed cell death (PCD) initiation and imaging-guided treatment, thus increasing the efficacy of tumor ablation and efficiently fighting against cancer. However, mild photothermal/radiation therapy with imaging-guided precise mediating PCD in solid tumors, involving processes related to apoptosis and ferroptosis, enhanced the effect of breast cancer inhibition is not fully understood.ResultsHerein, targeted peptide conjugated gold nano cages, iRGD-PEG/AuNCs@FePt NPs ternary metallic nanoparticles (Au@FePt NPs) were designed to achieve photoacoustic imaging (PAI)/Magnetic resonance imaging (MRI) guided synergistic therapy. Tumor-targeting Au@FePt forms reactive oxygen species (ROS), initiated by X-ray-induced dynamic therapy (XDT) in collaboration with photothermal therapy (PTT), inducing ferroptosis-augmented apoptosis to realize effective antitumor therapeutics. The relatively high photothermal conversion ability of Au@FePt increases the temperature in the tumor region and hastens Fenton-like processes to achieve enhanced synergistic therapy. Especially, RNA sequencing found Au@FePt inducting the apoptosis pathway in the transcriptome profile.ConclusionAu@FePt combined XDT/PTT therapy activate apoptosis and ferroptosis related proteins in tumors to achieve breast cancer ablation in vitro and in vivo. PAI/MRI images demonstrated Au@FePt has real-time guidance for monitoring synergistic anti-cancer therapy effect. Therefore, we have provided a multifunctional nanotheranostics modality for tumor inhibition and cancer management with high efficacy and limited side effects.Graphical

Cross-modality image translation: CT image synthesis of MR brain images using multi generative network with perceptual supervision

Background: Computed tomography (CT) and magnetic resonance imaging (MRI) are the mainstream imaging technologies for clinical practice. CT imaging can reveal high-quality anatomical and physiopathological structures, especially bone tissue, for clinical diagnosis. MRI provides high resolution in soft tissue and is sensitive to lesions. CT combined with MRI diagnosis has become a regular image-guided radiation treatment plan.Methods: In this paper, to reduce the dose of radiation exposure in CT examinations and ameliorate the limitations of traditional virtual imaging technologies, we propose a Generative MRI-to-CT transformation method with structural perceptual supervision. Even though structural reconstruction is structurally misaligned in the MRI-CT dataset registration, our proposed method can better align structural information of synthetic CT (sCT) images to input MRI images while simulating the modality of CT in the MRI-to-CT cross-modality transformation.Results: We retrieved a total of 3416 brain MRI-CT paired images as the train/test dataset, including 1366 train images of 10 patients and 2050 test images of 15 patients. Several methods (the baseline methods and the proposed method) were evaluated by the HU difference map, HU distribution, and various similarity metrics, including the mean absolute error (MAE), structural similarity index (SSIM), peak signal-to-noise ratio (PSNR), and normalized cross-correlation (NCC). In our quantitative experimental results, the proposed method achieves the lowest MAE mean of 0.147, highest PSNR mean of 19.27, and NCC mean of 0.431 in the overall CT test dataset.Conclusions: In conclusion, both qualitative and quantitative results of synthetic CT validate that the proposed method can preserve higher similarity of structural information of the bone tissue of target CT than the baseline methods. Furthermore, the proposed method provides better HU intensity reconstruction for simulating the distribution of the CT modality. The experimental estimation indicates that the proposed method is worth further investigation.

Specific Chemiluminescence Imaging and Enhanced Photodynamic Therapy of Bacterial Infections by Hemin-Modified Carbon Dots.

Antibacterial photodynamic therapy (aPDT) is a promising antibiotics-alternative strategy for bacterial infectious diseases, which features broad-spectrum antibacterial activity with a low risk of inducing bacterial resistance. However, clinical applications of aPDT are still hindered by the hydrophobicity-caused inadequate photodynamic activity of conventional photosensitizers and the hypoxic microenvironment of bacterial infections. To address these problems, herein, a promising strategy is developed to achieve specific chemiluminescence (CL) imaging and enhanced PDT of bacterial infections using hemin-modified carbon dots (H-CDs). The H-CDs can be facilely prepared and exhibit favorable water solubility, augmented photodynamic activity, and unique peroxidase-mimicking capacity. Compared with the free CDs, the photodynamic efficacy of H-CDs is significantly augmented due to the increased electron-hole separation efficiency. Moreover, the peroxidase catalytic performance of H-CDs enables not only infection identification via bacterial infection microenvironment-responsive CL imaging but also oxygen self-supplied aPDT with hypoxia-relief-enhanced bacteria inactivation effects. Finally, the enhanced aPDT efficiencies of H-CDs are validated in both in vivo abscess and infected wound models. This work may provide an effective antibacterial platform for the selective imaging-guided treatment of bacterial infections.

Evaluating Dual-Targeted ECO/siRNA Nanoparticles against an Oncogenic lncRNA for Triple Negative Breast Cancer Therapy with Magnetic Resonance Molecular Imaging.

Differentiation antagonizing noncoding RNA (DANCR) is recognized as an oncogenic long noncoding RNA (lncRNA) overexpressed in triple negative breast cancer (TNBC). We showed in a previous study that RNAi with targeted multifunctional ionizable lipid ECO/siRNA nanoparticles was effective to regulate this undruggable target for effective treatment of TNBC. In this study, we developed dual-targeted ECO/siDANCR nanoparticles by targeting a tumor extracellular matrix oncoprotein, extradomain B fibronectin (EDB-FN), and integrins overexpressed on cancer cells for enhanced delivery of siDANCR. The treatment of Hs578T TNBC cells and MCF-7 estrogen receptor-positive cells in vitro resulted in significant down-regulation of DANCR and EDB-FN and suppressed invasion and 3D spheroid formation of the cells. Magnetic resonance molecular imaging (MRMI) with an EDB-FN-targeted contrast agent, MT218, was used to noninvasively evaluate tumor response to treatment with the targeted ECO/siDANCR nanoparticles in female nude mice bearing orthotopic Hs578T and MCF-7 xenografts. MRMI with MT218 was effective to differentiate between aggressive TNBC with high DANCR and EDB-FN expression and ER+ MCF-7 tumors with low expression of the targets. MRMI showed that the dual-targeted ECO/siDANCR nanoparticles resulted in more significant inhibition of tumor growth in both models than the controls and significantly reduced EDB-FN expression in the TNBC tumors. The combination of MRMI and dual-targeted ECO/siDANCR nanoparticles is a promising approach for image-guided treatment of TNBC by regulating the onco-lncRNA.

Non-Surgical Definitive Treatment for Operable Breast Cancer: Current Status and Future Prospects.

This article reviews the results of various non-surgical curative treatments for operable breast cancer. Radiotherapy is considered the most important among such treatments, but conventional radiotherapy alone and concurrent chemoradiotherapy do not achieve high cure rates. As a radiosensitization strategy, intratumoral injection of hydrogen peroxide before radiation has been investigated, and high local control rates (75-97%) were reported. The authors treated 45 patients with whole-breast radiotherapy, followed by stereotactic or intensity-modulated radiotherapy boost, with or without a radiosensitization strategy employing either hydrogen peroxide injection or hyperthermia plus oral tegafur-gimeracil-oteracil potassium. Stages were 0-I in 23 patients, II in 19, and III in 3. Clinical and cosmetic outcomes were good, with 5-year overall, progression-free, and local recurrence-free survival rates of 97, 86, and 88%, respectively. Trials of carbon ion radiotherapy are ongoing, with promising interim results. Radiofrequency ablation, focused ultrasound, and other image-guided ablation treatments yielded complete ablation rates of 20-100% (mostly ≥70%), but long-term cure rates remain unclear. In these treatments, combination with radiotherapy seems necessary to treat the extensive intraductal components. Non-surgical treatment of breast cancer is evolving steadily, with radiotherapy playing a major role. In the future, proton therapy with the ultra-high-dose-rate FLASH mode is expected to further improve outcomes.

Hitting the Target of Image-Guided Psychiatry?

Hitting the Target of Image-Guided Psychiatry?

Endoscopic image-guided laser treatment system based on fiber bundle laser steering

A miniaturized endoscopic laser system with laser steering has great potential to expand the application of minimally invasive laser treatment for micro-lesions inside narrow organs. The conventional systems require separate optical paths for endoscopic imaging and laser steering, which limits their application inside narrower organs. Herein, we present a novel endoscopic image-guided laser treatment system with a thin tip that can access inside narrow organs. The system uses a single fiber bundle to simultaneously acquire endoscopic images and modulate the laser-irradiated area. The insertion and operation of the system in a narrow space were demonstrated using an artificial vascular model. Repeated laser steering along set targets demonstrated accurate laser irradiation within a root-mean-square error of 28 mum, and static repeatability such that the laser irradiation position was controlled within a 12 mum radius of dispersion about the mean trajectory. Unexpected irradiation on the distal irradiated plane due to fiber bundle crosstalk was reduced by selecting the appropriate laser input diameter. The laser steering trajectory spatially controlled the photothermal effects, vaporization, and coagulation of chicken liver tissue. This novel system achieves minimally invasive endoscopic laser treatment with high lesion-selectivity in narrow organs, such as the peripheral lung and coronary arteries.

Feasibility of Percutaneous Image-Guided Combined Treatment of Symptomatic Bone Cyst Using Cryoablation and Bone Graft Substitute.

To describe the feasibility and technique of percutaneous image-guided combined treatment of bone cyst (BC) using cryoablation and bone graft substitute injection. Between July 2019 and January 2022, six consecutive patients (ages between 16 and 33years) with symptomatic BC in pelvic and lower extremity bones underwent percutaneous image-guided combined treatment using cryoablation and bone graft substitute. To induce bone mineralization as early as possible, the cyst cavity was filled with bone graft substitute. Technical success of the procedure was evaluated, and clinical success was defined as satisfactory clinical symptom relief using visual analogue scale (VAS). Radiologic success was defined as early BC remineralization on radiographic studies. Detailed demographic data with lesion location, size, time to and degree of BC mineralization, complications, clinical outcomes, and radiological follow-up were retrospectively assessed. Technical success was 100% achieved in all patients. BC mineralization was observed in all patients, with a median time to reach 80% mineralization at 6months, with one patient reaching 80% at 5months and another reaching 100% at 3months. A significant drop in VAS was observed in all patients, reflecting significant pain relief. There were no major complications. The median follow-up period was 31.5months, with a minimum follow-up of 5months and a maximum follow-up of 3years. Percutaneous image-guided combined treatment with cryoablation and bone graft substitute for symptomatic BC is technically feasible and was safe in this limited series.

A hybrid deformable registration method to generate motion-compensated 3D virtual MRI for fusion with interventional real-time 3D ultrasound.

Ultrasound is often the preferred modality for image-guided therapy or treatment in organs such as liver due to real-time imaging capabilities. However, the reduced conspicuity of tumors in ultrasound images adversely impacts the precision and accuracy of treatment delivery. This problem is compounded by deformable motion due to breathing and other physiological activity. This creates the need for a fusion method to align interventional US with pre-interventional modalities that provide superior soft-tissue contrast (e.g., MRI) to accurately target a structure-of-interest and compensate for liver motion. In this work, we developed a hybrid deformable fusion method to align 3D pre-interventional MRI and 3D interventional US volumes to target the structures-of-interest in liver accurately in real-time. The deformable multimodal fusion method involved an offline alignment of a pre-intervention MRI with a pre-intervention US volume using a traditional registration method, followed by real-time prediction of deformation using a trained deep-learning model between interventional US volumes across different respiratory states. This framework enables motion-compensated MRI-US image fusion in real-time for image-guided treatment. The proposed hybrid deformable registration method was evaluated on three healthy volunteers across the pre-intervention MRI and 20 US volume pairs in the free-breathing respiratory cycle. The mean Euclidean landmark distance of three homologous targets in all three volunteers was less than 3 mm for percutaneous liver procedures. Preliminary results show that clinically acceptable registration accuracies for near real-time, deformable MRI-US fusion can be achieved by our proposed hybrid approach. The proposed combination of traditional and deep-learning deformable registration techniques is thus a promising approach for motion-compensated MRI-US fusion to improve targeting in image-guided liver interventions.

Expert recommendation on image-guided irreversible electroporation ablation treatment for renal carcinoma (2023 edition)

Irreversible electroporation ablation therapy can destroy tumor cells while retaining the integrity of the important surrounding physiological structures. It is suitable for patients with renal cell carcinoma who cannot be surgically resected or who do not want surgical resection, and can ensure the best postoperative renal function to the greatest extent, and has advantages that other thermal ablation treatments do not have. However, since irreversible electroporation therapy has high requirements for electrode needles and parameter settings, improper operation will directly affect the prognosis of patients. In order to improve the level of comprehensive treatment of renal cell cancer and standardize the operation technique of irreversible electroporation for renal cell carcinoma, the Committee of interventional minimally invasive therapy of the Chinese Medical Education Association took the lead in formulating the Expert Recommendation on image-guided irreversible electroporation ablation for Renal Cancer (2022 edition). The article introduces in detail the indications, contraindications, perioperative preparation, basic principles of operation, complications and related management and follow-up of irreversible electroporation for renal cell carcinoma, in order to provide reference for clinical practice.

Machine-learning-based prediction of the effectiveness of the delivered dose by exhale-gated radiotherapy for locally advanced lung cancer: The additional value of geometric over dosimetric parameters alone.

This study aimed to assess interfraction stability of the delivered dose distribution by exhale-gated volumetric modulated arc therapy (VMAT) or intensity-modulated arc therapy (IMAT) for lung cancer and to determine dominant prognostic dosimetric and geometric factors. Clinical target volume (CTVPlan) from the planning CT was deformed to the exhale-gated daily CBCT scans to determine CTVi, treated by the respective dose fraction. The equivalent uniform dose of the CTVi was determined by the power law (gEUDi) and cell survival model (EUDiSF) as effectiveness measure for the delivered dose distribution. The following prognostic factors were analyzed: (I) minimum dose within the CTVi (Dmin_i), (II) Hausdorff distance (HDDi) between CTVi and CTVPlan, (III) doses and deformations at the point in CTVPlan at which the global minimum dose over all fractions per patient occurs (PDmin_global_i), and (IV) deformations at the point over all CTVi margins per patient with the largest Hausdorff distance (HDPworst). Prognostic value and generalizability of the prognostic factors were examined using cross-validated random forest or multilayer perceptron neural network (MLP) classifiers. Dose accumulation was performed using back deformation of the dose distribution from CTVi to CTVPlan. Altogether, 218 dose fractions (10 patients) were evaluated. There was a significant interpatient heterogeneity between the distributions of the normalized gEUDi values (p<0.0001, Kruskal-Wallis tests). Accumulated gEUD over all fractions per patient was 1.004-1.023 times of the prescribed dose. Accumulation led to tolerance of ~20% of fractions with gEUDi <93% of the prescribed dose. Normalized Dmin >60% was associated with predicted gEUD values above 95%. Dmin had the highest importance for predicting the gEUD over all analyzed prognostic parameters by out-of-bag loss reduction using the random forest procedure. Cross-validated random forest classifier based on Dmin as the sole input had the largest Pearson correlation coefficient (R=0.897) in comparison to classifiers using additional input variables. The neural network performed better than the random forest classifier, and the gEUD values predicted by the MLP classifier with Dmin as the sole input were correlated with the gEUD values characterized by R=0.933 (95% CI, 0.913-0.948). The performance of the full MLP model with all geometric input parameters was slightly better (R=0.952) than that based on Dmin (p=0.0034, Z-test). Accumulated dose distributions over the treatment series were robust against interfraction CTV deformations using exhale gating and online image guidance. Dmin was the most important parameter for gEUD prediction for a single fraction. All other parameters did not lead to a markedly improved generalizable prediction. Dosimetric information, especially location and value of Dmin within the CTV i , are vital information for image-guided radiation treatment.

Image-Guided Precision Treatments.

Chemotherapy, radiotherapy, and surgery are traditional cancer treatments, which usually produce unpredictable side effects and potential risks to normal healthy organs/tissues. Thus, safe and reliable treatment strategies are urgently required for maximized therapeutic efficiency to lesions and minimized risks to healthy regions. To this end, molecular imaging is responsible to undertake a specific targeting therapy. Besides that, the image guidance as a precision visualized approach for real-time in situ evaluations as well as an intraoperational navigation approach has earned attractive attention in the past decade. Along with the rapid development of multifunctional micro-/nanobiomaterials, versatile cutting-edge and advanced therapy strategies (e.g., thermal therapy, dynamic therapy, gas therapy, etc.) have been achieved and greatly contributed to the image-guided precision treatments in every aspect. Therefore, this chapter aims to discuss about both traditional and advanced cancer treatments and especially to elucidate the important roles that visualized medicine has been playing in the image-guided precision treatments.

The spatial accuracy of ring-mounted halcyon linac versus C-arm TrueBeam linac for single-isocenter/multi-target SBRT treatment.

Stereotactic body radiotherapy (SBRT) treatment of oligometastatic lesions via single-isocenter/multi-target (SIMT) plan is more efficient than using multi-isocenter/multitarget SBRT. This study quantifies the spatial positioning accuracy of 2 commercially available LINAC systems for SIMT treatment pertaining to the potential amplification of error as a function of the target's distance-to-isocenter. We compare the Ring-Gantry Halcyon LINAC equipped with the fast iterative conebeam-CT (iCBCT) for image-guided SIMT treatment, and the SBRT-dedicated C-Arm TrueBeam with standard pretreatment CBCT imaging. For both systems, Sun Nuclear's MultiMet Winston-Lutz Cube phantom with 6 metallic BBs distributed at different planes up to 7 cm away from the isocenter was used. The phantom was aligned and imaged via CBCT, and then couch corrections were applied. To treat all 6 BBs, an Eclipse 10-field 3D-conformal Field-in-Field (2×2 cm2 MLC field to each BB) plan for varying gantry, collimator, and couch (TrueBeam only) positions was developed for both machines with 6MV-FFF beam. The plan was delivered through ARIA once a week. The EPID images were analyzed via Sun Nuclear's software for spatial positioning accuracy. On TrueBeam, the treatment plan was delivered twice: once with 3DoF translational corrections and once with PerfectPitch 6DoF couch corrections. The average 3D spatial positioning accuracy was 0.55 ± 0.30 mm, 0.54 ± 0.24 mm, and 0.56 ± 0.28 mm at isocenter, and 0.59 ± 0.30 mm, 0.69 ± 0.30 mm, and 0.70 ± 0.35 mm at 7 cm distance-to-isocenter for Halcyon, TrueBeam 3DoF, and TrueBeam 6DoF, respectively. This suggests there are no clinically significant deviations of spatial uncertainty between the platforms with the distance-to-isocenter. On both platforms, our weekly independent measurements demonstrated the reproducibility for less than 1.0 mm positional accuracy of off-axis targets up to 7 cm from the isocenter. Due to this, no additional PTV-margin is suggested for lesions within 7 cm of isocenter. This study confirms that Halcyon can deliver similar positional accuracy to SBRT-dedicated TrueBeam to off-axis targets up to 7 cm from isocenter. These results further benchmark the spatial uncertainty of our extensively used SBRT-dedicated TrueBeam LINAC for SIMT SBRT treatments.