Single vs. multiple fraction non-inferiority trial of stereotactic ablative radiotherapy for the comprehensive treatment of oligo-metastases/progression: SIMPLIFY-SABR-COMET.

BACKGROUND: Radiotherapy delivery regimens can vary between a single fraction (SF) and multiple fractions (MF) given daily for up to several weeks depending on the location of the cancer or metastases. With limited evidence comparing fractionation regimens for oligometastases, there is support to explore toxicity levels to nearby organs at risk as a primary outcome while using SF and MF stereotactic ablative radiotherapy (SABR) as well as explore differences in patient-reported quality of life and experience. METHODS: This study will randomize 598 patients in a 1:1 ratio between the standard arm (MF SABR) and the experimental arm (SF SABR). This trial is designed as two randomized controlled trials within one patient population for resource efficiency. The primary objective of the first randomization is to determine if SF SABR is non-inferior to MF SABR, with respect to healthcare provider (HCP)-reported grade 3-5 adverse events (AEs) that are related to SABR. Primary endpoint is toxicity while secondary endpoints include lesional control rate (LCR), and progression-free survival (PFS). The second randomization (BC Cancer sites only) will allocate participants to either complete quality of life (QoL) questionnaires only; or QoL questionnaires and a symptom-specific survey with symptom-guided HCP intervention. The primary objective of the second randomization is to determine if radiation-related symptom questionnaire-guided HCP intervention results in improved reported QoL as measured by the EuroQoL-5-dimensions-5levels (EQ-5D-5L) instrument. The primary endpoint is patient-reported QoL and secondary endpoints include: persistence/resolution of symptom reporting, QoL, intervention cost effectiveness, resource utilization, and overall survival. DISCUSSION: This study will compare SF and MF SABR in the treatment of oligometastases and oligoprogression to determine if there is non-inferior toxicity for SF SABR in selected participants with 1-5 oligometastatic lesions. This study will also compare patient-reported QoL between participants who receive radiation-related symptom-guided HCP intervention and those who complete questionnaires alone. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT05784428. Date of Registration: 23 March 2023.

Four-dimensional treatment planning strategies for dynamic tumor tracking.

INTRODUCTION: Dynamic tumor tracking (DTT) is a motion management technique where the radiation beam follows a moving tumor in real time. Not modelling DTT beam motion in the treatment planning system leaves an organ at risk (OAR) vulnerable to exceeding its dose limit. This work investigates two planning strategies for DTT plans, the "Boolean OAR Method" and the "Aperture Sorting Method," to determine if they can successfully spare an OAR while maintaining sufficient target coverage. MATERIALS AND METHODS: A step-and-shoot intensity modulated radiation therapy (sIMRT) treatment plan was re-optimized for 10 previously treated liver stereotactic ablative radiotherapy patients who each had one OAR very close to the target. Two planning strategies were investigated to determine which is more effective at sparing an OAR while maintaining target coverage: (1) the "Boolean OAR Method" created a union of an OAR's contours from two breathing phases (exhale and inhale) on the exhale phase (the planning CT) and protected this combined OAR during plan optimization, (2) the "Aperture Sorting Method" assigned apertures to the breathing phase where they contributed the least to an OAR's maximum dose. RESULTS: All 10 OARs exceeded their dose constraints on the original plan four-dimensional (4D) dose distributions and average target coverage was V100%  = 91.3% ± 2.9% (ranging from 85.1% to 94.8%). The "Boolean OAR Method" spared 7/10 OARs, and mean target coverage decreased to V100%  = 87.1% ± 3.8% (ranging from 80.7% to 93.7%). The "Aperture Sorting Method" spared 9/10 OARs and the mean target coverage remained high at V100%  = 91.7% ± 2.8% (ranging from 84.9% to 94.5%). CONCLUSIONS: 4D planning strategies are simple to implement and can improve OAR sparing during DTT treatments. The "Boolean OAR Method" improved sparing of OARs but target coverage was reduced. The "Aperture Sorting Method" further improved sparing of OARs and maintained target coverage.

Monte Carlo Modeling of Dynamic Tumor Tracking on a Gimbaled Linear Accelerator.

Purpose and Aim: The Vero4DRT (Brainlab AG) linear accelerator is capable of dynamic tumor tracking (DTT) by panning/tilting the radiation beam to follow respiratory-induced tumor motion in real time. In this study, the panning/tilting motion is modeled in Monte Carlo (MC) for quality assurance (QA) of four-dimensional (4D) dose distributions created within the treatment planning system (TPS). Materials and Methods: Step-and-shoot intensity-modulated radiation therapy plans were optimized for 10 previously treated liver patients. These plans were recalculated on multiple phases of a 4D computed tomography (4DCT) scan using MC while modeling panning/tilting. The dose distributions on each phase were accumulated to create a respiratory-weighted 4D dose distribution. Differences between the TPS and MC modeled doses were examined. Results: On average, 4D dose calculations in MC showed the maximum dose of an organ at risk (OAR) to be 10% greater than the TPS' three-dimensional dose calculation (collapsed cone [CC] convolution algorithm) predicted. MC's 4D dose calculations showed that 6 out of 24 OARs could exceed their specified dose limits, and calculated their maximum dose to be 4% higher on average (up to 13%) than the TPS' 4D dose calculations. Dose differences between MC and the TPS were greatest in the beam penumbra region. Conclusion: Modeling panning/tilting for DTT has been successfully modeled with MC and is a useful tool to QA respiratory-correlated 4D dose distributions. The dose differences between the TPS and MC calculations highlight the importance of using 4D MC to confirm the safety of OAR doses before DTT treatments.

Stereotactic Ablative Radiation Therapy for Colorectal Liver Metastases.

INTRODUCTION: Stereotactic Ablative Radiation Therapy (SABR) is a therapeutic option for patients with inoperable oligometastatic colorectal carcinoma (CRC). Given the scarcity of prospective data on outcomes of SABR for metastatic CRC, this study aims to review SABR outcomes and determine predictive factors of local control (LC) and survival in patients with liver metastases from CRC. MATERIALS AND METHODS: A retrospective review of SABR for CRC liver metastases between 2011 and 2019 was undertaken. Endpoints included LC, overall survival (OS), progression-free survival (PFS) and time to restarting systemic therapy. Univariate (UVA) and multivariable analyses (MVA) were performed to identify predictive factors. RESULTS: Forty-eight patients were identified. The total number of tumors treated was 58. Median follow-up was 26.6 months. LC at 1, 2 and 3 years was 92.7%, 80.0%, and 61.2% respectively. Median time to local failure was 40.0 months (95% CI 31.8-76.1 months). Median OS was 31.9 months (95% CI 20.6-40.0 months). OS at 1, 2, and 3 years was 79.2%, 61.7%, and 44.9% respectively. Thirty-three patients (69%) restarted systemic therapy after completion of SABR. Median time to restarting chemotherapy was 11.0 months (95% CI 7.1-17.6 months). Systemic therapy free survival at 1, 2, and 3 years was 45.7%, 29.6%, and 22.6% respectively. On MVA, inferior LC was influenced by GTV volume ≥40 cm3 (HR: 3.805, 95% CI 1.376-10.521, P = .01) and PTV D100% BED <100 Gy10 (HR 2.971, 95% CI 1.110-7.953; P = .03). Inferior OS was associated with PTV volume ≥200 cm3 (HR 5.679, 95% CI 2.339-13.755; P < .001). CONCLUSION: SABR is an effective therapeutic option for selected patients with CRC liver metastases providing acceptable LC within the first 2 years. In many cases, it provides meaningful chemotherapy-free intervals. Higher biological effective doses are required to enhance LC.

Four-dimensional dose calculations for dynamic tumour tracking with a gimbal-mounted linear accelerator.

PURPOSE: In this study we present a novel method for re-calculating a treatment plan on different respiratory phases by accurately modeling the panning and tilting beam motion during DTT (the "rotation method"). This method is used to re-calculate the dose distribution of a plan on multiple breathing phases to accurately assess the dosimetry. METHODS: sIMRT plans were optimized on a breath hold computed tomography (CT) image taken at exhale (BHexhale ) for 10 previous liver stereotactic ablative radiotherapy patients. Our method was used to re-calculate the plan on the inhale (0%) and exhale (50%) phases of the four-dimensional CT (4DCT) image set. The dose distributions were deformed to the BHexhale CT and summed together with proper weighting calculated from the patient's breathing trace. Subsequently, the plan was re-calculated on all ten phases using our method and the dose distributions were deformed to the BHexhale CT and accumulated together. The maximum dose for certain organs at risk (OARs) was compared between calculating on two phases and all ten phases. RESULTS: In total, 26 OARs were examined from 10 patients. When the dose was calculated on the inhale and exhale phases six OARs exceeded their dose limit, and when all 10 phases were used five OARs exceeded their limit. CONCLUSION: Dynamic tumor tracking plans optimized for a single respiratory phase leave an OAR vulnerable to exceeding its dose constraint during other respiratory phases. The rotation method accurately models the beam's geometry. Using deformable image registration to accumulate dose from all 10 breathing phases provides the most accurate results, however it is a time consuming procedure. Accumulating the dose from two extreme breathing phases (exhale and inhale) and weighting them properly provides accurate results while requiring less time. This approach should be used to confirm the safety of a DTT treatment plan prior to delivery.

The influence of Acuros XB on dose volume histogram metrics and tumour control probability modelling in locally advanced non-small cell lung cancer.

PURPOSE: Radiation therapy plans are assessed using dose volume metrics derived from clinical toxicity and outcome data. In this study, plans for patients with locally advanced non-small cell lung cancer (LA-NSCLC) are examined in the context of the implementation of the Acuros XB (AXB) dose calculation algorithm focussing on the impact on common metrics. METHODS: Volumetric modulated arc therapy (VMAT) plans were generated for twenty patients, using the Analytical Anisotropic Algorithm (AAA) and recalculated with AXB for both dose to water (Dw) and dose to medium (Dm). Standard dose volume histogram (DVH) metrics for both targets and organs-at-risk (OARs) were extracted, in addition to tumour control probability (TCP) for targets. RESULTS: Mean dose to the planning target volume (PTV) was not clinically different between the algorithms (within ±1.1 Gy) but differences were seen in the minimum dose, D99% and D98% as well as for conformity and homogeneity metrics. A difference in TCP was seen for AXBDm plans versus both AXBDw and AAA plans. No clinically relevant differences were seen in the lung metrics. For point doses to spinal cord and oesophagus, the AXBDm values were lower than AXBDw, by up to 1.0 Gy. CONCLUSION: Normalisation of plans to the mean/median dose to the target does not need to be adjusted when moving from AAA to AXB. OAR point doses may decrease by up to 1 Gy with AXBDm, which can be accounted for in clinical planning. Other OAR metrics do not need to be adjusted.

Determining normal tissue dose in intracranial stereotactic radiosurgery: A diameter-based predictive nomogram.

Purpose: A major factor in dose-fractionation selection for intracranial metastases in stereotactic radiosurgery (SRS) is the size of the target lesion and consequently the dose-volume to the surrounding normal brain tissue (NTV), as this has been correlated with brain radiation necrosis (RN). This study outlines the development and validation of a predictive model that can estimate the NTV for a range of dose-fractionation schemes based on target diameter from a patient's MRI. Methods: Data from a cohort of historical SRS clinical treatment plans were used to extract three key input parameters for the model - conformity index, gradient index, and a scaling factor which were then defined as a function of target volume. The relationship between the measured tumour diameter and the NTV was established by approximating the target to a spherical volume covered by the prescription dose. A scaling factor (λNTV) describes the non-linear fall-off of dose beyond the target. This was then used to provide a first-order approximation of the resulting NTV. The predictive model was retrospectively validated using linear regression against actual NTV values from 39 historical SRS plans which were independent to the derivation process. The model was validated for both three-dimensional (3D) target diameter and axial-only two-dimensional (2D) estimates of target diameter values. Results: The prediction model directly relates lesion diameter to NTV volume (cc) and thus RN risk for a given dose-fractionation. The predicted NTV (cc) for both 3D- and 2D-based volume estimates could statistically significantly predict the actual NTV (cc): R2=0.942 (p<.0005) for 3D-based estimate, and R2=0.911 (p=<.0005) for axial-only 2D-based estimate. Conclusion: This knowledge-based method for NTV prediction in intracranial SRS provides the clinician with a decision support tool to appropriately select dose-fractionation prior to treatment planning.

Adenocarcinoma of the lung: from BAC to the future.

Adenocarcinoma in situ, minimally invasive adenocarcinoma, lepidic predominant adenocarcinoma and invasive mucinous adenocarcinoma are relatively new classification entities which replace the now retired term, bronchoalveolar carcinoma (BAC). The radiographic appearance of these lesions ranges from pure, ground glass nodules to large, solid masses. A thorough understanding of the new classification is essential to radiologists who work with MDT colleagues to provide accurate staging and treatment. A 2-year review was performed of all surgically resected cases of adenocarcinoma in situ, minimally invasive adenocarcinoma and lepidic predominant adenocarcinoma in our institution. Cases are broken down by age, gender, tumour type and tumour location. A pictorial review is presented to illustrate the radiologic and pathologic features of each entity.

Imaging response assessment following stereotactic body radiotherapy for solid tumour metastases of the spine: Current challenges and future directions.

Patients with metastatic disease are routinely serially imaged to assess disease burden and response to systemic and local therapies, which places ever-expanding demands on our healthcare resources. Image interpretation following stereotactic body radiotherapy (SBRT) for spine metastases can be challenging; however, appropriate and accurate assessment is critical to ensure patients are managed correctly and resources are optimised. Here, we take a critical review of the merits and pitfalls of various imaging modalities, current response assessment guidelines, and explore novel imaging approaches and the potential for radiomics to add value in imaging assessment.

Putting affected people at the centre of humanitarian action: an argument for the principle of humanitarian subsidiarity.

The humanitarian system has grown organically over the course of a generation to become a complex system bound by a common primary mandate. Its guiding principles provide it with a unique identity and separate humanitarian actors from other aid-related stakeholders. However, all of the evidence suggests that humanitarian actors will extend their reach and engage in new and unprecedented ways with an expanded mandate in years to come. Now, more than ever, they are challenged to retain the moral high ground and to put disaster-affected people at the centre of humanitarian action. Consequently, this paper proposes that the humanitarian system introduce a new principle: humanitarian subsidiarity. It moves the conception of subsidiarity beyond meanings ascribed by the Catholic Church and the European Union and links it instead to the attributes of agency, accountability, and trust to find accommodation with the core humanitarian principles of humanity, impartiality, neutrality, and independence.

CT-guided Lung Biopsy: Effect of Biopsy-side Down Position on Pneumothorax and Chest Tube Placement.

Background Supine or prone positioning of the patient on the gantry table is the current standard of care for CT-guided lung biopsy; positioning biopsy side down was hypothesized to be associated with lower pneumothorax rate. Purpose To assess the effect of positioning patients biopsy side down during CT-guided lung biopsy on the incidence of pneumothorax, chest drain placement, and hemoptysis. Materials and Methods This retrospective study was performed between January 2013 and December 2016 in a tertiary referral oncology center. Patients undergoing CT-guided lung biopsy were either positioned in (a) the standard prone or supine position or (b) the lateral decubitus position with the biopsy side down. The relationship between patient position and pneumothorax, drain placement, and hemoptysis was assessed by using multivariable logistic regression models. Results A total of 373 consecutive patients (mean age ± standard deviation, 68 years ± 10), including 196 women and 177 men, were included in the study. Among these patients, 184 were positioned either prone or supine depending on the most direct path to the lesion and 189 were positioned biopsy side down. Pneumothorax occurred in 50 of 184 (27.2%) patients who were positioned either prone or supine and in 20 of 189 (10.6%) patients who were positioned biopsy side down (P < .001). Drain placement was required in 10 of 184 (5.4%) patients who were positioned either prone or supine and in eight of 189 (4.2%) patients who were positioned biopsy side down (P = .54). Hemoptysis occurred in 19 of 184 (10.3%) patients who were positioned prone or supine and in 10 of 189 (5.3%) patients who were positioned biopsy side down (P = .07). Prone or supine patient position (P = .001, odds ratio [OR] = 2.7 [95% confidence interval {CI}: 1.4, 4.9]), emphysema along the needle path (P = .02, OR = 2.1 [95% CI: 1.1, 4.0]), and lesion size (P = .02, OR = 1.0 [95% CI: 0.9, 1.0]) were independent risk factors for developing pneumothorax. Conclusion Positioning a patient biopsy side down for percutaneous CT-guided lung biopsy reduced the incidence of pneumothorax compared with the supine or prone position. © RSNA, 2019.

Cancer Trials Ireland (ICORG) 06-34: A multi-centre clinical trial using three-dimensional conformal radiation therapy to reduce the toxicity of palliative radiation for lung cancer.

TITLE: Cancer Trials Ireland (ICORG) 06-34: A multi-centre clinical trial using three-dimensional conformal radiation therapy to reduce the toxicity of palliative radiation for lung cancer. NCT01176487. BACKGROUND & PURPOSE: Trials of radiation therapy for the palliation of intra-thoracic symptoms from locally advanced non-small cell lung cancer (NSCLC) have concentrated on optimising fractionation and dose schedules. In these trials, the rates of oesophagitis induced by this "palliative" therapy have been unacceptably high. In contrast, this non-randomised, single-arm trial was designed to assess if more technically advanced treatment techniques would result in equivalent symptom relief and reduce the side-effect of symptomatic oesophagitis. MATERIALS & METHODS: Thirty-five evaluable patients with symptomatic locally advanced or metastatic NSCLC were treated using a three-dimensional conformal technique (3-DCRT) and standardised dose regimens of 39 Gy in 13 fractions, 20 Gy in 5 fractions or 17 Gy in 2 fractions. Treatment plans sought to minimise oesophageal dose. Oesophagitis was recorded during treatment, at two weeks, one month and three months following radiation therapy and 3-6 monthly thereafter. Mean dose to the irradiated oesophagus was calculated for all treatment plans. RESULTS: Five patients (14%) had experienced grade 2 oesophagitis or dysphagia or both during treatment and 2 other patients had these side effects at the 2-week follow-up. At follow-up of one month after therapy, there was no grade two or higher oesophagitis or dysphagia reported. 22 patients were eligible for assessment of late toxicity. Five of these patients reported oesophagitis or dysphagia (one had grade 3 dysphagia, two had grade 2 oesophagitis, one of whom also had grade 2 dysphagia). Quality of Life (QoL) data at baseline and at 1-month follow up were available for 20 patients. At 1-month post radiation therapy, these patients had slightly less trouble taking a short walk, less shortness of breath, did not feel as weak, had better appetite and generally had a better overall quality of life than they did at baseline. They did report being slightly more tired. CONCLUSIONS: This trial is the first of its kind showing that 3-DCRT provides patients with lower rates of oesophageal toxicity whilst yielding acceptable rates of symptom control. (Sponsored by Cancer Trials Ireland (ICORG) Study number 06-34, the Friends of St. Luke's and the St. Luke's Institute of Cancer Research.).

Pilot Investigation into the Use of an Anthropomorphic Breast Sonography Phantom as a Training and Assessment Tool.

A device for the training and quantitative assessment of the competency of trainee radiologists in the technically challenging area of breast sonography was developed and evaluated. Currently, suitable commercially available devices are lacking, and there is a growing realization that the reliance on direct exposure to patients for learning may not represent best practice from either the trainees' or patients' perspective. Three devices (PI, PII and PIII) were designed to produce very realistic sonographic images of breast morphology with a range of embedded pathologies. The pilot evaluation used a case study research design to evaluate the role of the anthropomorphic breast sonography training device in training and assessment in a clinical environment. Through the case study, it was possible to evaluate the process and relationships when using this type of training intervention for a small group of radiology resident trainees. The investigation involved a baseline assessment of trainees' (n = 4) ability to detect and characterize all lesions in PI, followed by a 4-wk training period on PII and a post-training assessment using PIII. The evaluation revealed an improvement of 30% ± 8% in the trainee's performance from pre- to post-training. It was expected that the performance of the trainees would improve as the training phantom described in this study aligns with the learning theory of constructivism and fits the ideal specifications of a medical training device in terms of its realism and facilitation of self-directed learning and deliberate practice of the trainees. The device provides a useful platform upon which training and assessment can be facilitated.

Human rights and proactive displacement: determining the appropriate balance between the duty to protect and the right to remain.

The proactive displacement by public authorities of populations from areas perceived to be exposed to a high risk of disaster presents complex human rights challenges. Provided that no ulterior motive is at play, the use of compulsory evacuations and relocations as policy responses to such risk is mandated by the duty to protect the right to life. However, proactive displacement in the interest of saving lives can be problematic as such measures can lead to the limitation of other human rights, resulting in an intricate assessment of whether compulsory evacuation or permanent relocation is proportional in any given circumstance. Such an analysis demands critical attention by public authorities to the perception of the disaster risk in question and problematises claims to objectivity of official risk assessments. Furthermore, it poses the question as to whether measures designed to address the disaster risk in question that are less intrusive than relocation may be available to public authorities.

Classical Hodgkin Lymphoma Arising Adjacent to a Breast Implant.

Breast implant-associated lymphoma has recently gained wide recognition. Anaplastic large cell lymphoma (ALCL) is the most frequently diagnosed subtype in this setting but the spectrum is broadening. A 66-year-old woman developed swelling and itch around her saline implant 6 years after its insertion. Imaging revealed a fluid collection surrounding the implant with an adjacent mass. Microscopy showed sclerotic tissue punctuated by discrete cellular nodules comprising small lymphocytes, eosinophils and interspersed large atypical Hodgkin Reed-Sternberg (HRS)-like cells. The HRS-like cells stained positively for CD30 and CD15 by immunohistochemistry. Small T-lymphocytes formed rosettes around HRS-like cells. Appearances were consistent with classical Hodgkin lymphoma (HL). Multiplex polymerase chain reaction demonstrated no clonal rearrangements of immunoglobulin or T-cell receptor genes, however, a t(14;18)(q32;q21)BCL2-JH translocation involving the major breakpoint region of the bcl2 gene was present. Staging positron emission tomography-computed tomography scan revealed FDG-avid masses in the right axilla and pelvis. Subsequent pathological examination identified low-grade follicular lymphoma (FL) with a t(14;18) translocation at these sites. To our knowledge, this is the first case of HL arising adjacent to a breast implant. An awareness of this diagnosis is important as classical HL, with its prominent mixed inflammatory background, may be overlooked as a reactive process when histologically assessing capsulectomy specimens. It is also important in the differential diagnosis for implant-associated ALCL as both contain large atypical CD30-positive cells highlighting the need for full immunohistochemical and molecular workup in such cases. This case also adds to the large body of literature regarding the association between HL and FL.

Neoadjuvant crizotinib in advanced inflammatory myofibroblastic tumour with ALK gene rearrangement.

BACKGROUND: Inflammatory myofibroblastic tumours (IMTs) are rare sarcomas that were first described in the lung. They are composed of myofibroblastic mesenchymal spindle cells accompanied by an inflammatory infiltrate of plasma cells. Complete resection is the treatment of choice. There is currently no standard treatment for inoperable or recurrent disease. Expression of ALK protein triggered by ALK gene rearrangement at chromosome 2p23 has been found in 36%-60% of IMTs. CASE REPORT: We report a rapid early response to crizotinib as neoadjuvant therapy, enabling surgical excision of a large ALK-translocated IMT, which resulted in complete disease clearance. To the best of our knowledge, this is the first case in the literature of a patient with IMT in whom crizotinib was used successfully in the neoadjuvant or curative setting.

Breast cancer outcomes following a national initiative in Ireland to restructure delivery of services for symptomatic disease.

BACKGROUND: A national initiative in Ireland in 2000 defined 13 designated Units to provide care for symptomatic breast cancer, and resources, including an ability to develop audit programmes, were provided. In the absence of a national audit of breast cancer outcomes, the aim of this study is to provide a detailed report of one Unit's subsequent experience, in particular comparing process and outcome data with international norms and benchmarks, and to infer on the likely impact of the national initiative. METHODS: A 5-year prospective audit of patients presenting to the Symptomatic Breast Clinic from 2001 to 2005 was conducted. All cancer diagnoses were discussed at the Breast Multidisciplinary Conference, and all clinicopathological treatment details and follow-up information were entered by a full-time data manager. Overall survival was calculated using the Kaplan-Meier method. RESULTS: Eight hundred and thirty-nine patients were diagnosed through the clinic, 18 (2%) Stage 0, 169 (20%) Stage I, 380 (45%) Stage II, 142 (17%) Stage III, and 123 (15%) Stage IV. At a median follow-up of 35 months the overall 5-year survival was 71%, with 100%, 91%, 83%, 72%, and 11% survival for Stages 0-IV, respectively, and disease-specific survival of 82%. CONCLUSIONS: The process and outcome data are consistent with international benchmarks. These data from one designated centre support the national initiatives in Ireland to restructure breast services.

Fat-suppressed dynamic and delayed gadolinium-enhanced volumetric interpolated breath-hold magnetic resonance imaging of cholangiocarcinoma.

OBJECTIVE: To determine the enhancement phase providing the highest contrast-to-noise ratio (CNR) between cholangiocarcinoma and liver or portal vein on dynamic and delayed gadolinium-enhanced magnetic resonance imaging (MRI). SUBJECTS AND METHODS: Precontrast, 3-phase dynamic postcontrast, and delayed postcontrast MRI of the liver was performed in 25 patients with cholangiocarcinoma and correlated with surgical findings, pathology, and other imaging studies. Contrast-to-noise ratios for tumor relative to adjacent liver and portal vein were calculated from signal intensities determined from regions of interest obtained for each phase of enhancement. A subjective assessment of the signal intensity of the periportal tissues relative to the portal vein was made for each set of delayed images. RESULTS: A mass was visible in 24 of 25 patients. Tumor masses were hypointense in 92%, 67%, 75%, and 21%; isointense in 8%, 8%, 17%, and 12%; and hyperintense in 0%, 25%, 8%, and 67% of patients relative to liver on precontrast, arterial, portal venous, and delayed images, respectively. No single phase of gadolinium enhancement demonstrated consistently superior tumor-versus-liver CNR. Delayed imaging demonstrated the highest tumor-versus-liver CNR in 25% of patients and the lowest in 33%. The portal venous phase demonstrated the highest tumor-versus-portal vein CNR in 75% of patients. Delayed postcontrast images demonstrated the lowest tumor-versus-portal vein CNR in 38% of patients. Periportal tissues were isointense to portal vein in all but 1 patient on delayed images. CONCLUSION: No single phase of dynamic and delayed gadolinium-enhanced MRI demonstrates superior CNR between cholangiocarcinoma and normally enhancing liver, although the portal phase provides the best CNR between tumor and portal vein in most cases. Although delayed enhancement is typical of cholangiocarcinoma, delayed imaging does not necessarily offer superior contrast between tumor and liver parenchyma compared with other phases of enhancement. Differentiation between tumor and portal vein and periportal tissues may be difficult on delayed images.