Sclerotherapy in the Treatment of Hydroceles: A Comprehensive Review of the Efficacy, Types of Sclerosants, and Comparative Outcomes Against Hydrocelectomy

While hydrocelectomy is the gold-standard for treating hydroceles, it poses an increased risk to patients and a greater burden to the healthcare system. Sclerotherapy is an alternative treatment for hydroceles that involves injecting a sclerosant into the hydrocele under ultrasound guidance. This literature review aimed to assess the types of sclerosants used and how sclerotherapy compares to hydrocelectomy. A literature search was conducted of MEDLINE and EMBASE using the terms "sclerotherapy" and "hydrocelectomy," which yielded 1058 studies, of which 29 met the inclusion criteria. Only studies published after 2000 were included to ensure the most recent information was reviewed. The results showed hydrocele sclerotherapy is done using a variety of sclerosants. The most used agents are polidocanol, phenol, and STS. Of these, phenol had the highest clinical success rate of 96.5%. There was evidence for the use of atypical agents, such as tetracycline antibiotics, which yielded cure rates up to 93%, and alcohol, which was found to be especially useful for treating multiseptated hydroceles. The results comparing sclerotherapy to hydrocelectomy indicated hydrocelectomy to be a more effective method in completely curing hydroceles. However, this came at the cost of more complications. Additionally, sclerotherapy was found to be more advantageous for secondary outcomes, such as healthcare costs and burden to patients. In conclusion, this review shows that while hydrocelectomy is more effective, sclerotherapy is a valuable alternative for treating hydroceles. Due to the lack of standardization among studies, a definitive conclusion cannot be made regarding which sclerosant is best to use.

[Analysis of Imaging Performance Standards of CBCT X-IGRT System Used in Radiotherapy]

This article briefly describes the imaging performance standards of the kilovolt X-ray image guidance system used in radiotherapy, analyzes the main aspects that should be considered in the image quality of X-IGRT system, and focuses on parameters that should be considered in the imaging performance evaluation criteria of the CBCT X-IGRT. The purpose is to sort out the imaging performance evaluation standards of kilovolt X-IGRT system, clarify the image quality requirements of X-IGRT equipment, and reach a consensus when evaluating the imaging performance of X-IGRT system.

Critical Appraisal of Paediatric Embryonal Cancers Treated with Image-guided Intensity-modulated Proton Therapy

AIM

To carry out a comprehensive critical appraisal of image-guided intensity-modulated proton therapy practice for craniospinal irradiation (CSI).

MATERIALS AND METHODS

An image-guided intensity-modulated proton therapy database of 45 consecutive paediatric patients with central nervous system embryonal malignancies treated between January 2019 and April 2022 were critically appraised for demography, diagnosis, treatment planning strategy and treatment delivery accuracy.

RESULTS

Most patients (median age: 7.5 years; male:female ratio: 34:11) had medulloblastoma (56%), followed by recurrent ependymoma (19%), pinealoblastoma (5%), germ cell (5%) and others (15%). The dose to the planning target volume-craniospinal (PTV-CS; length 39.06-79.59 cm) varied from 21 to 35 GyRBE, whereas the combined median dose to craniospinal and boost was 54 GyRBE. In all patients, the 95% isodose line covered the cribriform plate completely and optic nerves mostly, with a median V95% of 100% and 82.96%, keeping Dmax to the lens <3.9 GyRBE. In skeletally immature patients (88.38%), the anterior vertebral body was completely covered in 18.18% and underdosed in 70.15% of the cases, resulting in a median Dmean of 10.11 GyRBE to the oesophagus. Lateral spine coverage was maintained on the edges of the vertebral body in 52.2%, whereas it extended beyond in 48.8%. The median V98% for clinical target volumes and V95% for PTVs of the brain, spine and craniospinal were >97%, with excellent conformity (0.89) and homogeneity (0.07) indices for PTV-CS. All neurological organs at risk received a median Dmax ranging from 36 to 44 GyRBE from the combined CSI and boost regimens. Analysis of patient-specific quality assurance results revealed that 545 (97.67%) planar dosage verification had gamma (3% at 3 mm) values >95%. The online patient set-up verification showed translational and rotational deviation within 2 mm and 0.5° in 88-94% and 97% of the cases. Systematic and random error were within 0.90 mm and 1.71 mm in translation and 0.1° and 0.2° in rotation.

CONCLUSION

A change in practice pattern was observed. The findings from our comprehensive critical appraisal add to the growing library of CSI practice and may serve as a reference for inter-institutional comparison.

Technical advances in the surgical management of Wilms tumors in children

Surgery is one of the cornerstones of Wilms tumor treatment. In this article, we present technical advancements that are finding their way into the armamentarium of pediatric cancer surgeons. We discuss the current approaches, challenges, opportunities, and future directions of minimally invasive surgery (laparoscopic and robotics), image-guided surgery, and fluorescence-guided surgery. Furthermore, we discuss the use of intraoperative ultrasonography, as well as the use of new techniques to improve the quality of lymph node sampling.

Evaluating breast biopsy practice and breast biopsy marker utilisation in the clinical setting

INTRODUCTION

Breast Screen Australia and Breast Screen Aotearoa guidelines recommend breast biopsy marker (BBM) use in indicated patients. This study aims to evaluate breast biopsy practice and BBM utilisation by modality.

METHODS

An online survey was disseminated to radiologists who identified 'breast imaging' as their area of practice in the Royal Australian and New Zealand College of Radiologists (RANZCR) customer relationship management system. Survey questions addressed participant demographics and factors relating to BBM use.

RESULTS

Most respondents (72%) place between 1 and 4 BBMs per week. Almost all (99%) respondents perform ultrasound-guided biopsy of the breast or axillary nodes, with 85% performing stereotactic or tomosynthesis-guided breast biopsy and 27% performing MRI-guided breast biopsy. BBM utilisation differs by modality, with 97% respondents always placing a BBM post-MRI-guided breast biopsy, 50% always placing a BBM post-stereotactic-guided biopsy and 3% always placing a BBM post-ultrasound-guided breast biopsy.

CONCLUSIONS

Almost all radiologists perform breast biopsy using ultrasound, stereotactic/tomosynthesis or MRI guidance. BBM utilisation varies by modality, with 72% of respondents placing between 1 and 4 clips per week. Reasons for placing or not placing BBM aligned with prior studies. This is the first study to evaluate the number of breast biopsies performed by radiologists on a weekly or monthly basis, providing a useful platform for comparison in the local setting.

Identifying the therapeutic zone in globus pallidus deep brain stimulation for Parkinson's disease

OBJECTIVE

The globus pallidus internus (GPI) has been demonstrated to be an effective surgical target for deep brain stimulation (DBS) treatment in patients with medication-refractory Parkinson's disease (PD). The ability of neurosurgeons to define the area of greatest therapeutic benefit within the globus pallidus (GP) may improve clinical outcomes in these patients. The objective of this study was to determine the best DBS therapeutic implantation site within the GP for effective treatment in PD patients.

METHODS

The authors performed a retrospective review of 56 patients who underwent bilateral GP DBS implantation at their institution during the period from January 2015 to January 2020. Each implanted contact was anatomically localized. Patients were followed for stimulation programming for at least 6 months. The authors reviewed preoperative and 6-month postsurgery clinical outcomes based on data from the Unified Parkinson's Disease Rating Scale Part III (UPDRS III), dyskinesia scores, and levodopa equivalent daily dose (LEDD).

RESULTS

Of the 112 leads implanted, the therapeutic cathode was most frequently located in the lamina between the GPI external segment (GPIe) and the GP externus (GPE) (n = 40). Other common locations included the GPE (n = 24), the GPIe (n = 15), and the lamina between the GPI internal segment (GPIi) and the GPIe (n = 14). In the majority of patients (73%) a monopolar programming configuration was used. At 6 months postsurgery, UPDRS III off medications (OFF) and on stimulation (ON) scores significantly improved (z = -4.02, p < 0.001), as did postsurgery dyskinesia ON scores (z = -4.08, p < 0.001) and postsurgery LEDD (z = -4.7, p < 0.001).

CONCLUSIONS

Though the ventral GP (pallidotomy target) has been a commonly used target for GP DBS, a more dorsolateral target may be more effective for neuromodulation strategies. The assessment of therapeutic contact locations performed in this study showed that the lamina between GPI and GPE used in most patients is the optimal central stimulation target. This information should improve preoperative GP targeting.

Urinary Outcomes After Magnetic Resonance Imaging-Guided Whole-Gland Transurethral Ultrasound Ablation for Prostate Cancer: Comparison of Suprapubic Tube to Indwelling Urethral Catheter

Background: MRI-guided transurethral ultrasound ablation (TULSA) is under investigation for whole-gland ablation of low- and intermediate-risk prostate cancer. The ideal method for post-TULSA bladder drainage through postoperative suprapubic tube (SPT) vs indwelling urethral catheter (UC) has not been established. The objective of this study was to evaluate urinary outcomes after whole-gland TULSA, comparing postoperative SPT with UC. Materials and Methods: Two-institution retrospective analysis of whole-gland TULSA for men with grade group 1 and 2 prostate cancer. One institution placed SPT at the time of TULSA with clamp trials (day 10) and removal once voiding. The second placed UC until void trial (day 7). Outcomes included the International Prostate Symptom Score (IPSS), urinary bother score, catheter reinsertion, stricture, clean intermittent catheterization (CIC), and incontinence. Results: Forty-five patients (median age 67) were analyzed. The UC cohort (N = 26) was older (p = 0.007) than the SPT cohort (N = 19) but with similar baseline prostate volumes, IPSS, and urinary bother scores. Patients receiving UC had fewer days with catheter (p = 0.013). Although UC patients suffered more lower urinary tract symptoms at 1-month post-TULSA, there was no significant difference between IPSS scores at baseline and 6 months after surgery regardless of urinary management strategy, although the UC group noted significantly decreased urinary bother. Rates of infection were similar between groups. Six strictures were observed overall, with more in the SPT group, although the difference was not significant (4/19 [21.1%] SPT; 2/26 [7.7%] UC). At 6 months, incontinence rates were low and similar between groups (2/19 [10.5%] SPT; 4/26 [15.4%] UC) and only one patient (UC) required CIC. Conclusions: Our overall findings suggest that SPT and UC are both acceptable options for postoperative bladder drainage after whole-gland TULSA, with statistically similar rates of urinary complications but a slightly different side effect profile.

Reporting of Inter Fraction Dose Variations of Organs at Risk in Computed Tomography-Guided High Dose Rate Intracavitary Brachytherapy in Carcinoma Cervix

Assess the interfraction dose variations of the organs at risk (OARs) in carcinoma cervix high dose rate (HDR) computed tomography (CT)-guided intra cavitary brachytherapy (ICBT). 120 CT scans of 40 patients who had undergone three fractions of ICBT (7 Gy/fr) were analyzed. Dose to Point A and the minimum doses to the volumes of 2, 1, and 0.1cc of bladder, rectum and sigmoid colon were recorded. Revised plans were generated in 20 patients. Paired t-test was used to compare the difference in the means. Point "A" mean dose difference was statistically significant between the treated and revised plans. For bladder, the difference in means of dosage to all volumes, whilst for the rectum and sigmoid colon, the low volume dosage (0.1cc) was statistically significant. Absence of individualized planning would have resulted in underdosage of tumor and increased dosage of up to 30% to OARs. CT-guided ICBT should be implemented for each HDR fraction treatment.

Nanoparticle-assisted, image-guided laser interstitial thermal therapy for cancer treatment

Laser interstitial thermal therapy (LITT) guided by magnetic resonance imaging (MRI) is a new treatment option for patients with brain and non-central nervous system (non-CNS) tumors. MRI guidance allows for precise placement of optical fiber in the tumor, while MR thermometry provides real-time monitoring and assessment of thermal doses during the procedure. Despite promising clinical results, LITT complications relating to brain tumor procedures, such as hemorrhage, edema, seizures, and thermal injury to nearby healthy tissues, remain a significant concern. To address these complications, nanoparticles offer unique prospects for precise interstitial hyperthermia applications that increase heat transport within the tumor while reducing thermal impacts on neighboring healthy tissues. Furthermore, nanoparticles permit the co-delivery of therapeutic compounds that not only synergize with LITT, but can also improve overall effectiveness and safety. In addition, efficient heat-generating nanoparticles with unique optical properties can enhance LITT treatments through improved real-time imaging and thermal sensing. This review will focus on (1) types of inorganic and organic nanoparticles for LITT; (2) in vitro, in silico, and ex vivo studies that investigate nanoparticles' effect on light-tissue interactions; and (3) the role of nanoparticle formulations in advancing clinically relevant image-guided technologies for LITT. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease Implantable Materials and Surgical Technologies > Nanoscale Tools and Techniques in Surgery.

Efficacy of a single, image-guided corticosteroid injection for glenohumeral arthritis

BACKGROUND

Limited data are available on the efficacy of cortisone injections for glenohumeral osteoarthritis (GHOA). The amount and longevity of pain relief provided by a single cortisone injection are unclear. Additionally, it remains uncertain how the severity of radiographic GHOA and patient-reported function and pain levels impact the efficacy of an injection. Therefore, we sought to describe the relief provided by a single, image-guided glenohumeral injection in patients with GHOA. We hypothesized that patients with more severe radiographic GHOA and poorer baseline shoulder function would require earlier secondary intervention.

METHODS

Patients with symptomatic GHOA who elected to receive a corticosteroid injection for pain relief were prospectively enrolled. A phone interview was conducted to record the baseline Oxford Shoulder Score (OSS) and visual analog scale (VAS) score prior to the injection, as well as the OSS and VAS score at months 1, 2, 3, 4, 6, 9, and 12 after the injection. The endpoint of the study occurred when patients required a second injection, progressed to surgery, or reached month 12. Patients were grouped by their respective baseline OSS (mild vs. moderate or severe) and Samilson-Prieto radiographic classification (mild, moderate, or severe) for analysis.

RESULTS

We analyzed 30 shoulders (29 patients). Of the patients, 52% were men. The average age was 66.1 years. No significant difference in overall survival (defined as no additional intervention) was seen between groups based on either the OSS or Samilson-Prieto grade. Additionally, the OSS and VAS score at each follow-up were compared with baseline values. For the entire cohort, a clinically significant difference was seen between baseline and months 1-4 for the OSS and between baseline and months 1-4, 6, 9, and 12 for the VAS score.

DISCUSSION

This study aimed to determine the efficacy of corticosteroid injections for GHOA. There were no differences in the need for secondary intervention in this population based on the severity of either the OSS or the Samilson-Prieto radiographic classification. However, patients with more severe shoulder dysfunction based on the OSS did experience statistically significantly greater symptomatic relief than patients with milder dysfunction. Additionally, following a single injection, patients in this cohort experienced statistically and clinically relevant improvements in shoulder function and pain up to 4 months after injection.

Current state of navigation in spine surgery

The use of navigation has become more prevalent in spine surgery. The multitude of available platforms, as well as increased availability of navigation systems, have led to increased use worldwide. Specific subsets of spine surgeons have incorporated this new technology in their practices, including minimally invasive spine (MIS) spine surgeons, neurosurgeons, and high-volume surgeons. Improved accuracy with the use of navigation has been demonstrated and its use has proven to be a safe alternative to fluoroscopic guided procedures. Navigation use allows the limitation of radiation exposure to the surgeon during common spine procedures, which over the course of a surgeon's lifetime may offer significant health benefits. Navigation has also been beneficial in tumor resection and MIS surgery, where traditional anatomic landmarks are missing or in the case of MIS not visible. As cost effectiveness improves, the use of navigation is likely to continue to expand. Navigation will also continue to expand with further innovation such as coupling the use of navigation with robotics and improving tools to enhance the end user experience.

Magnetic Resonance Imaging-Guided Transurethral Ultrasound Ablation of Prostate Cancer

PURPOSE

Magnetic resonance imaging-guided transurethral ultrasound ablation uses directional thermal ultrasound under magnetic resonance imaging thermometry feedback control for prostatic ablation. We report 12-month outcomes from a prospective multicenter trial (TACT).

MATERIALS AND METHODS

A total of 115 men with favorable to intermediate risk prostate cancer across 13 centers were treated with whole gland ablation sparing the urethra and apical sphincter. The co-primary 12-month endpoints were safety and efficacy.

RESULTS

In all, 72 (63%) had grade group 2 and 77 (67%) had NCCN® intermediate risk disease. Median treatment delivery time was 51 minutes with 98% (IQR 95-99) thermal coverage of target volume and spatial ablation precision of ±1.4 mm on magnetic resonance imaging thermometry. Grade 3 adverse events occurred in 9 (8%) men. The primary endpoint (U.S. Food and Drug Administration mandated) of prostate specific antigen reduction ≥75% was achieved in 110 of 115 (96%) with median prostate specific antigen reduction of 95% and nadir of 0.34 ng/ml. Median prostate volume decreased from 37 to 3 cc. Among 68 men with pretreatment grade group 2 disease, 52 (79%) were free of grade group 2 disease on 12-month biopsy. Of 111 men with 12-month biopsy data, 72 (65%) had no evidence of cancer. Erections (International Index of Erectile Function question 2 score 2 or greater) were maintained/regained in 69 of 92 (75%). Multivariate predictors of persistent grade group 2 at 12 months included intraprostatic calcifications at screening, suboptimal magnetic resonance imaging thermal coverage of target volume and a PI-RADS™ 3 or greater lesion at 12-month magnetic resonance imaging (p <0.05).

CONCLUSIONS

The TACT study of magnetic resonance imaging-guided transurethral ultrasound whole gland ablation in men with localized prostate cancer demonstrated effective tissue ablation and prostate specific antigen reduction with low rates of toxicity and residual disease.

How image-guided core needle biopsies altered the treatment of breast disease: Challenges accepted and opportunities taken

The technique of combining stereotactic targeting of breast lesions with an automated spring-loaded needle biopsy gun reported in 1990 by Steve Parker and colleagues not only ushered in the era of diagnosis almost exclusively by image guided core needle biopsy, but also profoundly changed the practice of pathologists, radiologists, surgeons, and medical oncologists and had major effects on the treatment of women with breast cancer. In this special issue of The Breast Journal celebrating 25 years of publication, it is of value to reflect back on these changes, some expected and some unanticipated, which have occurred over the past three decades and to consider the reasons why core needle biopsies should be considered a milestone in breast pathology.

Computer Navigation vs Conventional Total Hip Arthroplasty: A Medicare Database Analysis

BACKGROUND

Computer-assisted surgery (CAS) is applied to total hip arthroplasty (THA) in an attempt to optimize implant positioning. The effect of CAS on postoperative complications after THA remains unknown. Our study aims to assess the change in complication rates when CAS is used in THA.

METHODS

The Medicare database was studied from 2005 to 2012. All THAs performed with CAS were identified. A total of 64,944 THAs were identified, including 5412 CAS-THAs and 59,532 conventional THAs. Medical and surgical adverse events were collected at various time points.

RESULTS

CAS-THA was not associated with a decreased rate of dislocation at 30 days (1.0% vs 1.2%; odds ratio [OR], 1.14; P = .310), 90 days (1.1% vs 1.4%; OR, 1.23; P = .090), or 2 years (2.3% vs 2.3%; OR, 1.01; P = .931). CAS-THA was associated with a significantly higher rate of periprosthetic fracture at 30 days (0.4% vs 0.6%; OR, 1.46; P = .040) as well as revision THA at 30 days (1.0% vs 1.4%; OR, 1.43; P = .003) and 90 days (1.2% vs 1.7%; OR, 1.42; P < .002) when compared to conventional THA. CAS-THA was associated with a significantly lower rate of deep vein thrombosis and pulmonary embolism when compared to conventional THA at all time points (P < .05).

CONCLUSION

Administrative coding data fail to demonstrate any clinically significant reduction in short-term adverse events with CAS-THA. Further study is warranted to evaluate whether the purported benefits of CAS result in a reduction of the adverse events after THA.

Treatment of locally advanced cervical cancer in a patient with a bicornuate uterus with MRI-guided intracavitary/interstitial brachytherapy

Purpose

Definitive treatment for locally advanced cervical cancer (LACC) includes external beam radiation therapy (EBRT) with concurrent cisplatin and brachytherapy. Image-guided intracavitary brachytherapy utilizes CT and/or MRI for target and organ at risk delineation and has been shown to improve local control rates and decrease toxicity. Hybrid intracavitary/interstitial applicators can be used to improve tumor coverage in certain cases. We describe the use of combined intracavitary/interstitial brachytherapy to treat a cervical cancer patient with a bicornuate uterus.

Case presentation

A 30-year-old female with bicornuate uterus and FIGO IB2 adenocarcinoma of the cervix was treated with 45 Gy of EBRT to the pelvis with concurrent weekly cisplatin. An examination after EBRT demonstrated a persistent bulky tumor covering most of the cervix. Brachytherapy was delivered via a combined intracavitary/interstitial approach, using a tandem and ring applicator and an interstitial needle. The placement of the tandem was alternated between uterine cornua with each fraction, and the interstitial needle was placed on the side opposite the tandem. CT and MRI were obtained with each fraction. The patient completed the treatment without complications. Three-month restaging PET-CT showed significant interval improvement in the cervix, with a complete clinical response on physical examination. The patient is without evidence of disease 18 months after the treatment.

Conclusions

We found that the use of the hybrid applicator allowed for adequate target coverage in a patient with unusual anatomy. The patient tolerated treatment well and demonstrated favorable response on follow-up exam and imaging. The long-term curative result needs to be further evaluated.

Polypeptide-Conjugated Second Near-Infrared Organic Fluorophore for Image-Guided Photothermal Therapy

Image-guided photothermal therapy (PTT) is an attractive strategy to improve the diagnosis accuracy and treatment outcomes by monitoring the accumulation of photothermal agents in tumors in real-time and determining the best treatment window. Taking advantage of the superior imaging quality of NIR-II fluorescence imaging and remote-controllable phototherapy modality of PTT, we developed a facile macromolecular fluorophore (PF) by conjugating a small-molecule NIR-II fluorophore (Flav7) with an amphiphilic polypeptide. The PF can form uniform micelles in aqueous solution, which exhibit a slight negative charge. In vitro experimental results showed that the PF nanoparticles showed satisfactory photophysical properties, prominent photothermal conversion efficiency (42.3%), excellent photothermal stability, negligible cytotoxicity, and photothermal toxicity. Meanwhile, the PF can visualize and feature the tumors by NIR-II fluorescence imaging owing to prolonged blood circulation time and enhanced accumulation in tumors. Moreover, in vivo studies revealed that the PF nanoparticles achieved an excellent photothermal ablation effect on tumors with a low dose of NIR-II dye and light irradiation, and the process can be traced by NIR fluorescence imaging.

Percutaneous nephrolithotomy in a case of retrorenal colon: A descriptive approach and literature review

Introduction

Percutaneous nephrolithotomy procedure is generally used to treat stones resistant to other treatment modalities. Colonic perforation even though rare, is a serious complication that increases patient's morbidity. This case report describes the case of a patient with retrorenal colon who underwent percutaneous nephrolithotomy for management of pelvis/lower calyceal staghorn stone.

Case presentation

A 63‐year‐old female patient presented for the management of a staghorn pelvis‐lower calyceal stone. The patient had a preoperative computed tomography scan of the abdomen and pelvis that showed an incidental finding of left retrorenal colon. Under computed tomography scan guidance, a nephrostomy tube was successfully placed by an interventional radiologist, and then she underwent percutaneous nephrolithotomy.

Conclusion

This case report aims to stress on the importance of doing a computed tomography scan whenever a prior abdominal surgery is performed. We strongly believe that gastrointestinal injuries could be avoided by using computed tomography guided access in high risk patients.

Magnetic Resonance Conditional Microinjector

Glaucoma, one of the leading causes of blindness, has been linked to increases in intraocular pressure. In order to observe and study this effect, proposed is a specialized microinjector and driver that can be used to inject small amounts of liquid into a target volume. Magnetic resonance imaging (MRI) guided remotely activated devices require specialized equipment that is compatible with the MR environment. This paper presents an MR Conditional microinjector system with a pressure sensor for investigating the effects of intraocular pressure (IOP) in near-real-time. The system uses pressurized air and a linear actuation device to push a syringe in a controlled, stepwise manner. The feasibility and utility of the proposed investigative medical research tool were tested and validated by measuring the pressure inside an intact animal donor eyeball while precise, small volumes of water were injected into the specimen. Observable increases in the volume of the specimen at measured, specific target pressure increases show that the system is technically feasible for studying IOP effects, while the changes in shape were depicted in MRI scan images themselves. In addition, it was verified that the presence and operation of the system did not interfere with the MRI machine, confirming its conditional compatibility with the 3T MRI.

Adaptive Radiotherapy Enabled by MRI Guidance

Adaptive radiotherapy (ART) strategies systematically monitor variations in target and neighbouring structures to inform treatment-plan modification during radiotherapy. This is necessary because a single plan designed before treatment is insufficient to capture the actual dose delivered to the target and adjacent critical structures during the course of radiotherapy. Magnetic resonance imaging (MRI) provides superior soft-tissue image contrast over current standard X-ray-based technologies without additional radiation exposure. With integrated MRI and radiotherapy platforms permitting motion monitoring during treatment delivery, it is possible that adaption can be informed by real-time anatomical imaging. This allows greater treatment accuracy in terms of dose delivered to target with smaller, individualised treatment margins. The use of functional MRI sequences would permit ART to be informed by imaging biomarkers, so allowing both personalised geometric and biological adaption. In this review, we discuss ART solutions enabled by MRI guidance and its potential gains for our patients across tumour types.

Minimally invasive guidewireless, navigated pedicle screw placement: a technical report and case series

OBJECTIVE Percutaneous pedicle screw insertion (PPSI) is a mainstay of minimally invasive spinal surgery. Traditionally, PPSI is a fluoroscopy-guided, multistep process involving traversing the pedicle with a Jamshidi needle, placement of a Kirschner wire (K-wire), placement of a soft-tissue dilator, pedicle tract tapping, and screw insertion over the K-wire. This study evaluates the accuracy and safety of PPSI with a simplified 2-step process using a navigated awl-tap followed by navigated screw insertion without use of a K-wire or fluoroscopy. METHODS Patients undergoing PPSI utilizing the K-wire-less technique were identified. Data were extracted from the electronic medical record. Complications associated with screw placement were recorded. Postoperative radiographs as well as CT were evaluated for accuracy of pedicle screw placement. RESULTS Thirty-six patients (18 male and 18 female) were included. The patients' mean age was 60.4 years (range 23.8-78.4 years), and their mean body mass index was 28.5 kg/m² (range 20.8-40.1 kg/m²). A total of 238 pedicle screws were placed. A mean of 6.6 pedicle screws (range 4-14) were placed over a mean of 2.61 levels (range 1-7). No pedicle breaches were identified on review of postoperative radiographs. In a subgroup analysis of the 25 cases (69%) in which CT scans were performed, 173 screws were assessed; 170 (98.3%) were found to be completely within the pedicle, and 3 (1.7%) demonstrated medial breaches of less than 2 mm (Grade B). There were no complications related to PPSI in this cohort. CONCLUSIONS This streamlined 2-step K-wire-less, navigated PPSI appears safe and accurate and avoids the need for radiation exposure to surgeon and staff.

Fractionated Radiosurgery Alone for Thirty-seven Brain Metastases: Not Everything that can be Counted Counts

There is an ongoing debate as to the maximum number of brain metastases that can safely and practically be treated with a single course of radiosurgery. Despite evidence of durable local control and favorable overall survival when treating 10 or more brain metastases with radiosurgery alone, some institutions and guidelines still limit radiosurgery to an arbitrary number of metastases.

As demonstrated by this case report, the number of lesions is not so important when the patient’s life expectancy is otherwise good and body tumors are controllable. In the current era of effective targeted therapies, multi-year survival with brain metastases is increasingly common. Treating 37 brain metastases simultaneously in a five-fraction stereotactic course is technically feasible and in this case, resulted in 100% local and distant control in the brain for 18 months ongoing without any additional brain radiation. We discuss patient selection factors when treating large numbers of brain metastases, and present a possible class solution when using five daily fractions of 6 Gray (Gy) with a single plan and isocenter.

Remotely Triggered Nano-Theranostics For Cancer Applications

Nanotechnology has enabled the development of smart theranostic platforms that can concurrently diagnose disease, start primary treatment, monitor response, and, if required, initiate secondary treatments. Recent in vivo experiments demonstrate the promise of using theranostics in the clinic. In this paper, we review the use of remotely triggered theranostic nanoparticles for cancer applications, focusing heavily on advances in the past five years. Remote triggering mechanisms covered include photodynamic, photothermal, phototriggered chemotherapeutic release, ultrasound, electro-thermal, magneto-thermal, X-ray, and radiofrequency therapies. Each section includes a brief overview of the triggering mechanism and summarizes the variety of nanoparticles employed in each method. Emphasis in each category is placed on nano-theranostics with in vivo success. Some of the nanotheranostic platforms highlighted include photoactivatable multi-inhibitor nanoliposomes, plasmonic nanobubbles, reduced graphene oxide-iron oxide nanoparticles, photoswitching nanoparticles, multispectral optoacoustic tomography using indocyanine green, low temperature sensitive liposomes, and receptor-targeted iron oxide nanoparticles loaded with gemcitabine. The studies reviewed here provide strong evidence that the field of nanotheranostics is rapidly evolving. Such nanoplatforms may soon enable unique advances in the clinical management of cancer. However, reproducibility in the synthesis procedures of such "smart" platforms that lend themselves to easy scale-up in their manufacturing, as well as the development of new and improved models of cancer that are more predictive of human responses, need to happen soon for this field to make a rapid clinical impact.

Positional Accuracy of Treating Multiple Versus Single Vertebral Metastases With Stereotactic Body Radiotherapy

The aim of this study is to determine whether stereotactic body radiotherapy for multiple vertebral metastases treated with a single isocenter results in greater intrafraction errors than stereotactic body radiotherapy for single vertebral metastases and to determine whether the currently used spinal cord planning organ at risk volume and planning target volume margins are appropriate. Intrafraction errors were assessed for 65 stereotactic body radiotherapy treatments for vertebral metastases. Cone beam computed tomography images were acquired before, during, and after treatment for each fraction. Residual translational and rotational errors in patient positioning were recorded and planning organ at risk volume and planning target volume margins were calculated in each direction using this information. The mean translational residual errors were smaller for single (0.4 (0.4) mm) than for multiple vertebral metastases (0.5 (0.7) mm; P = .0019). The mean rotational residual errors were similar for single (0.3° (0.3°) and multiple vertebral metastases (0.3° (0.3°); P = .862). The maximum calculated planning organ at risk volume margin in any direction was 0.83 mm for single and 1.22 for multiple vertebral metastases. The maximum calculated planning target volume margin in any direction was 1.4 mm for single and 1.9 mm for multiple vertebral metastases. Intrafraction errors were small for both single and multiple vertebral metastases, indicating that our strategy for patient immobilization and repositioning is robust. Calculated planning organ at risk volume and planning target volume margins were smaller than our clinically employed margins, indicating that our clinical margins are appropriate.

Survey of image-guided radiotherapy use in Australia

INTRODUCTION

This study aimed to evaluate the current use of imaging technologies for planning and delivery of radiotherapy (RT) in Australia.

METHODS

An online survey was emailed to all Australian RT centres in August 2015. The survey inquired about imaging practices during planning and treatment delivery processes. Participants were asked about the types of image-guided RT (IGRT) technologies and the disease sites they were used for, reasons for implementation, frequency of imaging and future plans for IGRT use in their department.

RESULTS

The survey was completed by 71% of Australian RT centres. All respondents had access to computed tomography (CT) simulators and regularly co-registered the following scans to the RT: diagnostic CT (50%), diagnostic magnetic resonance imaging (MRI) (95%), planning MRI (34%), planning positron emission tomography (PET) (26%) and diagnostic PET (97%) to aid in tumour delineation. The main reason for in-room IGRT implementation was the use of highly conformal techniques, while the most common reason for under-utilisation was lack of equipment capability. The most commonly used IGRT modalities were kilovoltage (kV) cone-beam CT (CBCT) (97%), kV electronic portal image (EPI) (89%) and megavoltage (MV) EPI (75%). Overall, participants planned to increase IGRT use in planning (33%) and treatment delivery (36%).

CONCLUSIONS

IGRT is widely used among Australian RT centres. On the basis of future plans of respondents, the installation of new imaging modalities is expected to increase for both planning and treatment.

A Systematic Analysis of Errors in Target Localization and Treatment Delivery for Stereotactic Radiosurgery Using 2D/3D Image Registration

PURPOSE

To determine the localization uncertainties associated with 2-dimensional/3-dimensional image registration in comparison to 3-dimensional/3-dimensional image registration in 6 dimensions on a Varian Edge Linac under various imaging conditions.

METHODS

The systematic errors in 6 dimensions were assessed by comparing automatic 2-dimensional/3-dimensional (kV/MV vs computed tomography) with 3-dimensional/3-dimensional (cone beam computed tomography vs computed tomography) image registrations under various conditions encountered in clinical applications. The 2-dimensional/3-dimensional image registration uncertainties for 88 patients with different treatment sites including intracranial and extracranial were evaluated by statistically analyzing 2-dimensional/3-dimensional pretreatment verification shifts of 192 fractions in stereotactic radiosurgery and stereotactic body radiotherapy.

RESULTS

The systematic errors of 2-dimensional/3-dimensional image registration using kV-kV, MV-kV, and MV-MV image pairs were within 0.3 mm and 0.3° for the translational and rotational directions within a 95% confidence interval. No significant difference ( P > .05) in target localization was observed with various computed tomography slice thicknesses (0.8, 1, 2, and 3 mm). Two-dimensional/3-dimensional registration had the best accuracy when pattern intensity and content filter were used. For intracranial sites, means ± standard deviations of translational errors were -0.20 ± 0.70 mm, 0.04 ± 0.50 mm, and 0.10 ± 0.40 mm for the longitudinal, lateral, and vertical directions, respectively. For extracranial sites, means ± standard deviations of translational errors were -0.04 ± 1.00 mm, 0.2 ± 1.0 mm, and 0.1 ± 1.0 mm for the longitudinal, lateral, and vertical directions, respectively. Two-dimensional/3-dimensional image registration for intracranial and extracranial sites had comparable systematic errors that were approximately 0.2 mm in the translational direction and 0.08° in the rotational direction.

CONCLUSION

The standard 2-dimensional/3-dimensional image registration tool available on the Varian Edge radiosurgery device, a state-of-the-art system, is helpful for robust and accurate target positioning for image-guided stereotactic radiosurgery.

High-Intensity Focused Ultrasound: Current Status for Image-Guided Therapy

Image-guided high-intensity focused ultrasound (HIFU) is an innovative therapeutic technology, permitting extracorporeal or endocavitary delivery of targeted thermal ablation while minimizing injury to the surrounding structures. While ultrasound-guided HIFU was the original image-guided system, MR-guided HIFU has many inherent advantages, including superior depiction of anatomic detail and superb real-time thermometry during thermoablation sessions, and it has recently demonstrated promising results in the treatment of both benign and malignant tumors. HIFU has been employed in the management of prostate cancer, hepatocellular carcinoma, uterine leiomyomas, and breast tumors, and has been associated with success in limited studies for palliative pain management in pancreatic cancer and bone tumors. Nonthermal HIFU bioeffects, including immune system modulation and targeted drug/gene therapy, are currently being explored in the preclinical realm, with an emphasis on leveraging these therapeutic effects in the care of the oncology patient. Although still in its early stages, the wide spectrum of therapeutic capabilities of HIFU offers great potential in the field of image-guided oncologic therapy.

Preclinical evaluation of a novel CEA-targeting near-infrared fluorescent tracer delineating colorectal and pancreatic tumors

Surgery is the cornerstone of oncologic therapy with curative intent. However, identification of tumor cells in the resection margins is difficult, resulting in nonradical resections, increased cancer recurrence and subsequent decreased patient survival. Novel imaging techniques that aid in demarcating tumor margins during surgery are needed. Overexpression of carcinoembryonic antigen (CEA) is found in the majority of gastrointestinal carcinomas, including colorectal and pancreas. We developed ssSM3E/800CW, a novel CEA-targeted near-infrared fluorescent (NIRF) tracer, based on a disulfide-stabilized single-chain antibody fragment (ssScFv), to visualize colorectal and pancreatic tumors in a clinically translatable setting. The applicability of the tracer was tested for cell and tissue binding characteristics and dosing using immunohistochemistry, flow cytometry, cell-based plate assays and orthotopic colorectal (HT-29, well differentiated) and pancreatic (BXPC-3, poorly differentiated) xenogeneic human-mouse models. NIRF signals were visualized using the clinically compatible FLARE™ imaging system. Calculated clinically relevant doses of ssSM3E/800CW selectively accumulated in colorectal and pancreatic tumors/cells, with highest tumor-to-background ratios of 5.1 ± 0.6 at 72 hr postinjection, which proved suitable for intraoperative detection and delineation of tumor boarders and small (residual) tumor nodules in mice, between 8 and 96 hr postinjection. Ex vivo fluorescence imaging and pathologic examination confirmed tumor specificity and the distribution of the tracer. Our results indicate that ssSM3E/800CW shows promise as a diagnostic tool to recognize colorectal and pancreatic cancers for fluorescent-guided surgery applications. If successfully translated clinically, this tracer could help improve the completeness of surgery and thus survival.

Using preoperative imaging for intraoperative guidance: a case of mistaken identity

BACKGROUND

Surgical image guidance systems to date have tended to rely on reconstructions of preoperative datasets. This paper assesses the accuracy of these reconstructions to establish whether they are appropriate for use in image guidance platforms.

METHODS

Nine raters (two experts in image interpretation and preparation, three in image interpretation, and four in neither interpretation nor preparation) were asked to perform a segmentation of ten renal tumours (four cystic and six solid tumours). These segmentations were compared with a gold standard consensus segmentation generated using a previously validated algorithm.

RESULTS

Average sensitivity and positive predictive value (PPV) were 0.902 and 0.891, respectively. When assessing for variability between raters, significant differences were seen in the PPV, sensitivity and incursions and excursions from consensus tumour boundary.

CONCLUSIONS

This paper has demonstrated that the interpretation required for the segmentation of preoperative imaging of renal tumours introduces significant inconsistency and inaccuracy. Copyright © 2015 John Wiley & Sons, Ltd.

Microrecording and image-guided stereotactic biopsy of deep-seated brain tumors

OBJECT

Image-guided stereotactic brain tumor biopsy cannot easily obtain samples of small deep-seated tumor or selectively sample the most viable region of malignant tumor. Image-guided stereotactic biopsy in combination with depth microrecording was evaluated to solve such problems.

METHODS

Operative records, MRI findings, and pathological specimens were evaluated in 12 patients with small deep-seated brain tumor, in which image-guided stereotactic biopsy was performed with the aid of depth microrecording. The tumors were located in the caudate nucleus (1 patient), thalamus (7 patients), midbrain (2 patients), and cortex (2 patients). Surgery was performed with a frameless stereotactic system in 3 patients and with a frame-based stereotactic system in 9 patients. Microrecording was performed to study the electrical activities along the trajectory in the deep brain structures and the tumor. The correlations were studied between the electrophysiological, MRI, and pathological findings. Thirty-two patients with surface or large brain tumor were also studied, in whom image-guided stereotactic biopsy without microrecording was performed.

RESULTS

The diagnostic yield in the group with microrecording was 100% (low-grade glioma 4, high-grade glioma 4, diffuse large B-cell lymphoma 3, and germinoma 1), which was comparable to 93.8% in the group without microrecording. The postoperative complication rate was as low as that of the conventional image-guided method without using microelectrode recording, and the mortality rate was 0%, although the target lesions were small and deep-seated in all cases. Depth microrecording revealed disappearance of neural activity in the tumor regardless of the tumor type. Neural activity began to decrease from 6.3 ± 4.5 mm (mean ± SD) above the point of complete disappearance along the trajectory. Burst discharges were observed in 6 of the 12 cases, from 3 ± 1.4 mm above the point of decrease of neural activity. Injury discharges were often found at 0.5-1 mm along the trajectory between the area of decreased and disappeared neural activity. Close correlations between electrophysiological, MRI, and histological findings could be found in some cases.

CONCLUSIONS

Image-guided stereotactic biopsy performed using depth microrecording was safe, it provided accurate positional information in real time, and it could distinguish the tumor from brain structures during surgery. Moreover, this technique has potential for studying the epileptogenicity of the brain tumor.

Targeting Accuracy of Image-Guided Radiosurgery for Intracranial Lesions: A Comparison Across Multiple Linear Accelerator Platforms

PURPOSE

To evaluate the overall positioning accuracy of image-guided intracranial radiosurgery across multiple linear accelerator platforms.

METHODS

A computed tomography scan with a slice thickness of 1.0 mm was acquired of an anthropomorphic head phantom in a BrainLAB U-frame mask. The phantom was embedded with three 5-mm diameter tungsten ball bearings, simulating a central, a left, and an anterior cranial lesion. The ball bearings were positioned to radiation isocenter under ExacTrac X-ray or cone-beam computed tomography image guidance on 3 Linacs: (1) ExacTrac X-ray localization on a Novalis Tx; (2) cone-beam computed tomography localization on the Novalis Tx; (3) cone-beam computed tomography localization on a TrueBeam; and (4) cone-beam computed tomography localization on an Edge. Each ball bearing was positioned 5 times to the radiation isocenter with different initial setup error following the 4 image guidance procedures on the 3 Linacs, and the mean (µ) and one standard deviation (σ) of the residual error were compared.

RESULTS

Averaged overall 3 ball bearing locations, the vector length of the residual setup error in mm (µ ± σ) was 0.6 ± 0.2, 1.0 ± 0.5, 0.2 ± 0.1, and 0.3 ± 0.1 on ExacTrac X-ray localization on a Novalis Tx, cone-beam computed tomography localization on the Novalis Tx, cone-beam computed tomography localization on a TrueBeam, and cone-beam computed tomography localization on an Edge, with their range in mm being 0.4 to 1.1, 0.4 to 1.9, 0.1 to 0.5, and 0.2 to 0.6, respectively. The congruence between imaging and radiation isocenters in mm was 0.6 ± 0.1, 0.7 ± 0.1, 0.3 ± 0.1, and 0.2 ± 0.1, for the 4 systems, respectively.

CONCLUSIONS

Targeting accuracy comparable to frame-based stereotactic radiosurgery can be achieved with image-guided intracranial stereotactic radiosurgery treatment.

Virtual HDR CyberKnife SBRT for Localized Prostatic Carcinoma: 5-Year Disease-Free Survival and Toxicity Observations

PURPOSE

Prostate stereotactic body radiotherapy (SBRT) may substantially recapitulate the dose distribution of high-dose-rate (HDR) brachytherapy, representing an externally delivered "Virtual HDR" treatment method. Herein, we present 5-year outcomes from a cohort of consecutively treated virtual HDR SBRT prostate cancer patients.

METHODS

Seventy-nine patients were treated from 2006 to 2009, 40 low-risk, and 39 intermediate-risk, under IRB-approved clinical trial, to 38 Gy in four fractions. The planning target volume (PTV) included prostate plus a 2-mm volume expansion in all directions, with selective use of a 5-mm prostate-to-PTV expansion and proximal seminal vesicle coverage in intermediate-risk patients, to better cover potential extraprostatic disease; rectal PTV margin reduced to zero in all cases. The prescription dose covered >95% of the PTV (V100 ≥95%), with a minimum 150% PTV dose escalation to create "HDR-like" PTV dose distribution.

RESULTS

Median pre-SBRT PSA level of 5.6 ng/mL decreased to 0.05 ng/mL 5 years out and 0.02 ng/mL 6 years out. At least one PSA bounce was seen in 55 patients (70%) but only 3 of them subsequently relapsed, biochemical-relapse-free survival was 100 and 92% for low-risk and intermediate-risk patients, respectively, by ASTRO definition (98 and 92% by Phoenix definition). Local relapse did not occur, distant metastasis-free survival was 100 and 95% by risk-group, and disease-specific survival was 100%. Acute and late grade 2 GU toxicity incidence was 10 and 9%, respectively; with 6% late grade 3 GU toxicity. Acute urinary retention did not occur. Acute and late grade 2 GI toxicity was 0 and 1%, respectively, with no grade 3 or higher toxicity. Of patient's potent pre-SBRT, 65% remained so at 5 years.

CONCLUSION

Virtual HDR prostate SBRT creates a very low PSA nadir, a high rate of 5-year disease-free survival and an acceptable toxicity incidence, with results closely resembling those reported post-HDR brachytherapy.

Irreversible electroporation: ready for prime time?

Image-guided ablation has evolved rapidly in the past decade into a competitive technique for treating focal solid malignancies. However, as they rely mainly on thermal energy, such as radiofrequency or microwave, many tumors close to sensitive organs, such as ducts, bowel, and nerves, still remain nonablatable owing to the risk of thermal injury. Irreversible electroporation is a novel ablation modality that relies largely on a nonthermal mechanism to induce cell death, and therefore may overcome many of the shortcomings of thermal ablation. Emerging preclinical data as well as early clinical experience is showing promise for this technique in treating a variety of tumors including periportal liver masses, pancreatic cancer, perihilar renal tumors, prostate cancer, and other soft tissue tumors. However, practical limitations remain for irreversible electroporation, and its complete cancer and location-specific safety and efficacy profiles are still largely unknown. We therefore review what is known for this new ablation modality based on preclinical and preliminary clinical data, and discuss its emerging indications as well as technical challenges.

Potential role of ultrasound imaging in interstitial image based cervical cancer brachytherapy

In 2012, more than 500,000 cases of cervical cancer were diagnosed worldwide. Over three quarters of these cases occur in less developed countries [1]. Advancements in image-guided brachytherapy are resulting in improved outcomes and reduced morbidity for women with this disease, but its worldwide adoption is hampered by lack of accessibility to advanced imaging techniques. Ultrasound is emerging as a potential option for tumor visualization, brachytherapy catheter placement, and treatment planning. While additional work is needed, ultrasound can potentially serve as the sole imaging modality for catheter insertion and planning. This paper will review our current knowledge on the use of ultrasound in interstitial brachytherapy treatment for cervical cancer.

Image-guided percutaneous aspiration and gelfoam treatment of petrous apex cholesterol granuloma: a new theory and method for diagnosis and treatment

Although diagnosis of cholesterol granulomas of the skull base can be straightforward with computed tomography (CT) and magnetic resonance imaging (MRI) appearance, treatment is controversial with various skull base approaches described in the literature. This report describes a 35-year-old man who presented with a symptomatic, enlarging cystic lesion in the left petrous apex and clivus that had imaging features of a cholesterol granuloma (cholesterol cyst). Due to a prior history of treated mediastinal germ cell tumor, pathologic confirmation of the lesion was requested. A CT-guided percutaneous aspiration revealed dark used motor oil-like fluid. Continued aspiration yielded a change in the character of the fluid to marrow red. Injection of contrast revealed no communication with cerebrospinal fluid. Gelfoam (Pfizer, New York, New York, USA) was subsequently injected percutaneously into the residual cavity. Histopathology showed no evidence of malignancy and follow-up MRI at 1 month, 3 months, 6 months, and 1 year demonstrated continued decrease in size and signal of the lesion.

Minimally invasive image-guided cochlear implantation surgery: first report of clinical implementation

OBJECTIVES/HYPOTHESIS

Minimally invasive image-guided approach to cochlear implantation (CI) involves drilling a narrow, linear tunnel to the cochlea. Reported herein is the first clinical implementation of this approach.

STUDY DESIGN

Prospective cohort study.

METHODS

On preoperative computed tomography (CT), a safe linear trajectory through the facial recess targeting the scala tympani was planned. Intraoperatively, fiducial markers were bone-implanted, a second CT was acquired, and the trajectory was transferred from preoperative to intraoperative CT. A customized microstereotactic frame was rapidly designed and constructed to constrain a surgical drill along the desired trajectory. Following sterilization, the frame was employed to drill the tunnel to the middle ear. After lifting a tympanomeatal flap and performing a cochleostomy, the electrode array was threaded through the drilled tunnel and into the cochlea.

RESULTS

Eight of nine patients were successfully implanted using the proposed approach with six insertions completely within the scala tympani. Traditional mastoidectomy was performed on one patient following difficulty threading the electrode array via the narrow tunnel. Other difficulties encountered included use of the backup implant when an electrode was dislodged during threading via the tunnel, tip fold-over, and facial nerve paresis (House-Brackmann II/VI at 12 months) secondary to heat during drilling. The average time of intervention was 182 ± 36 minutes.

CONCLUSIONS

Minimally invasive image-guided CI is clinically achievable. Further clinical study is necessary to address technological difficulties during drilling and insertion, and to assess potential benefits including decreased time of intervention, standardization of surgical intervention, and decreased tissue dissection potentially leading to shorter recovery and earlier implant activation.

CT-guided, minimally invasive, postmortem needle biopsy using the B-Rob II needle-positioning robot

CT-guided, minimally invasive needle biopsy techniques can be used to retrieve tissue or body fluid samples for histologic tissue diagnoses in forensic investigations. The purpose of this study was an evaluation of CT-guided needle-positioning robot B-Rob II. To operate under CT guidance, we adopted the B-Rob II robotic needle placement system and its workflow. The accuracy and speed of the procedure were tested on a gelatin phantom in a series of 21 biopsies. We achieved an average needle placement accuracy of 1.8 mm (±1.1 mm) using robotic assistance. The procedure required an average of 2 min 21 s. The needle placement accuracy for minimally invasive needle biopsies using the B-Rob II biopsy robot is sufficiently accurate and fast for forensic postmortem examinations of focal organ changes. Further tests will be performed to test the feasibility of the robot for performing biopsies of focal organ changes in human bodies.

Tumor characterization in small animals using magnetic resonance-guided dynamic contrast enhanced diffuse optical tomography

We present a magnetic resonance (MR)-guided near-infrared dynamic contrast enhanced diffuse optical tomography (DCE-DOT) system for characterization of tumors using an optical contrast agent (ICG) and a MR contrast agent [Gd-diethylenetriaminepentaacetic acid (DTPA)] in a rat model. Both ICG and Gd-DTPA are injected and monitored simultaneously using a combined MRI-DOT system, resulting in accurate co-registration between two imaging modalities. Fisher rats bearing R3230 breast tumor are imaged using this hybrid system. For the first time, enhancement kinetics of the exogenous contrast ICG is recovered from the DCE-DOT data using MR anatomical a priori information. As tumors grow, they undergo necrosis and the tissue transforms from viable to necrotic. The results show that the physiological changes between viable and necrotic tissue can be differentiated more accurately based on the ICG enhancement kinetics when MR anatomical information is utilized.

Inflammatory pseudotumor of the spleen: review of clinical presentation and diagnostic methods

We describe a 91-year-old woman with a clinical history of invasive ductal carcinoma of the breast diagnosed in 1991 who was admitted because of dizziness, poor appetite, and some swelling and tenderness over her cheeks. The patient's initial work up revealed a 5-cm well-demarcated hypodense solid lesion in her spleen with abnormally intense uptake on PET/CT scan raising suspicion for malignancy i.e. breast metastasis versus lymphoma. Further review demonstrated the presence of this splenic lesion, though slightly smaller, on a CT scan from ten years earlier (2000). An ultrasonographic guided core needle splenic biopsy was performed and the pathology result revealed histological findings compatible with inflammatory pseudotumor of the spleen. As a result, unnecessary splenectomy was avoided.