Accuracy of digital mammography, ultrasound and MRI in predicting the pathological complete response and residual tumor size of breast cancer after completion of neoadjuvant chemotherapy

Background: Neoadjuvant chemotherapy (NACT) is the standard of care for the treatment of locally advanced or non-metastatic breast cancer, which may increase the chances of breast conservative surgery (BCS) in place of radical mastectomy without compromising on the overall survival. The aim of this study was to evaluate the accuracy of mammography (MG), ultrasound (US), and magnetic resonance imaging (MRI) in predicting the complete response and to assess the extent of residual breast cancer in women treated with NACT. Materials and Methods: Fifty-six consecutive patients with stage II or III breast cancer, who underwent imaging evaluation of breast with digital mammogram, US, and MRI after NACT and before the breast surgery, were included in the study. For each patient, pathologic complete response (pCR) or residual tumor (non-pCR) was predicted and the maximum extent of the residual tumor was measured on each imaging modality. These measurements were subsequently compared with the final histopathology results. Results: Of 56 patients, 22 showed pCR with MRI having better accuracy for predicting complete response than the MG and US (area under the receiver operating characteristic curve: 0.86, 0.68, and 0.65, respectively; p = 0.0001 for MRI; p = 0.06 for MG, and p = 0.02 for US). The sensitivity of MRI for detecting pCR was 72.7%; specificity and positive predictive value were 100%. For pathological residual tumor, the size measured on MRI showed significantly higher correlation with the pathologic size (correlation coefficient, r = 0.786), than the MG (r = 0.293) and US (r = 0.508) with P < 0.05. Conclusions: Accuracy of MRI for predicting pathological complete response was significantly higher than the MG and US. Pathologic residual tumor size was also more precisely reflected by the longest tumor dimension on MRI with the strong positive correlation coefficient

Targeting uptake transporters for cancer imaging and treatment

Cancer cells reprogram their gene expression to promote growth, survival, proliferation, and invasiveness. The unique expression of certain uptake transporters in cancers and their innate function to concentrate small molecular substrates in cells make them ideal targets for selective delivering imaging and therapeutic agents into cancer cells. In this review, we focus on several solute carrier (SLC) transporters known to be involved in transporting clinically used radiopharmaceutical agents into cancer cells, including the sodium/iodine symporter (NIS), norepinephrine transporter (NET), glucose transporter 1 (GLUT1), and monocarboxylate transporters (MCTs). The molecular and functional characteristics of these transporters are reviewed with special emphasis on their specific expressions in cancers and interaction with imaging or theranostic agents [., I-123, I-131, I-iobenguane (mIBG), F-fluorodeoxyglucose (F-FDG) and C pyruvate]. Current clinical applications and research areas of these transporters in cancer diagnosis and treatment are discussed. Finally, we offer our views on emerging opportunities and challenges in targeting transporters for cancer imaging and treatment. By analyzing the few clinically successful examples, we hope much interest can be garnered in cancer research towards uptake transporters and their potential applications in cancer diagnosis and treatment.

Surface-enhanced Raman nanoparticles for tumor theranostics applications

Raman spectroscopy, amplified by surface-enhanced Raman scattering (SERS) nanoparticles, can provide an imaging modality due to its high molecular specificity, high sensitivity, and negligible autofluorescence. The basis, composition, and methodologies developed for SERS nanoparticles are herein described. The research hotspots that are the focus in this paper are tumor imaging-guided theranostics and biosensing. The next breakthrough may be the development of biocompatible SERS nanoparticles and spectroscopic devices for clinical applications.

Quality of Radiomic Features in Glioblastoma Multiforme: Impact of Semi-Automated Tumor Segmentation Software

OBJECTIVE: The purpose of this study was to evaluate the reliability and quality of radiomic features in glioblastoma multiforme (GBM) derived from tumor volumes obtained with semi-automated tumor segmentation software. MATERIALS AND METHODS: MR images of 45 GBM patients (29 males, 16 females) were downloaded from The Cancer Imaging Archive, in which post-contrast T1-weighted imaging and fluid-attenuated inversion recovery MR sequences were used. Two raters independently segmented the tumors using two semi-automated segmentation tools (TumorPrism3D and 3D Slicer). Regions of interest corresponding to contrast-enhancing lesion, necrotic portions, and non-enhancing T2 high signal intensity component were segmented for each tumor. A total of 180 imaging features were extracted, and their quality was evaluated in terms of stability, normalized dynamic range (NDR), and redundancy, using intra-class correlation coefficients, cluster consensus, and Rand Statistic. RESULTS: Our study results showed that most of the radiomic features in GBM were highly stable. Over 90% of 180 features showed good stability (intra-class correlation coefficient [ICC] ≥ 0.8), whereas only 7 features were of poor stability (ICC NDR ≥1), while above 35% of the texture features showed poor NDR (< 1). Features were shown to cluster into only 5 groups, indicating that they were highly redundant. CONCLUSION: The use of semi-automated software tools provided sufficiently reliable tumor segmentation and feature stability; thus helping to overcome the inherent inter-rater and intra-rater variability of user intervention. However, certain aspects of feature quality, including NDR and redundancy, need to be assessed for determination of representative signature features before further development of radiomics.

Evidence-Based Cancer Imaging

With the advances in the field of oncology, imaging is increasingly used in the follow-up of cancer patients, leading to concerns about over-utilization. Therefore, it has become imperative to make imaging more evidence-based, efficient, cost-effective and equitable. This review explores the strategies and tools to make diagnostic imaging more evidence-based, mainly in the context of follow-up of cancer patients.

Applications of Low Energy Megavoltage X-ray Beams in Cancer Radiotherapy.

A review on the applications of low energy megavoltage (MV) X-ray beams (1-4 MV) in cancer radiotherapy is presented. Firstly, the physical characteristics of low energy megavoltage X-ray beams are reviewed in terms of penumbra, dose fall-off, exit dose, dose to bone, penetration power, skin dose and image quality. Secondly, the therapeutic applications of low energy megavoltage X-rays in cancer radiotherapy are further stratified and discussed based on X-ray energy levels. Thirdly, a systematic review of imaging applications of low energy megavoltage Xray beams in image-guided radiation therapy (IGRT) and megavoltage fan beam computed tomography (MVFBCT) is provided. Finally, we summarize the latest development of low energy megavoltage X-ray beams in cancer radiotherapy and cancer imaging during the past twenty years. With their intrinsic physical characteristics, it is feasible to achieve personalized radiotherapy and personalized imaging protocols for individual patient. However, further technological developments and more clinical data would be needed to fully exploit the potentials of low energy megavoltage X-ray beams in the personalized radiotherapeutic management of cancers.

Functional magnetic resonance imaging in oncology: state of the art / Ressonância magnética funcional na oncologia: estado da arte

In the investigation of tumors with conventional magnetic resonance imaging, both quantitative characteristics, such as size, edema, necrosis, and presence of metastases, and qualitative characteristics, such as contrast enhancement degree, are taken into consideration. However, changes in cell metabolism and tissue physiology which precede morphological changes cannot be detected by the conventional technique. The development of new magnetic resonance imaging techniques has enabled the functional assessment of the structures in order to obtain information on the different physiological processes of the tumor microenvironment, such as oxygenation levels, cellularity and vascularity. The detailed morphological study in association with the new functional imaging techniques allows for an appropriate approach to cancer patients, including the phases of diagnosis, staging, response evaluation and follow-up, with a positive impact on their quality of life and survival rate.

O estudo convencional dos tumores por ressonância magnética avalia tanto características morfológicas e quantitativas, tais como tamanho, edema, necrose e presença de metástases, quanto características qualitativas, como grau de realce pós-contraste. Entretanto, as mudanças no metabolismo celular e na fisiologia tecidual que precedem as mudanças morfológicas não são detectadas com a técnica convencional. O desenvolvimento de novas técnicas de imagem por ressonância magnética possibilitou a avaliação funcional das estruturas, no intuito de obter informações sobre os diferentes processos fisiológicos do microambiente tumoral, como níveis de oxigenação, celularidade e vascularização. O detalhado estudo morfológico, aliado às novas técnicas de imagem funcional, permite que o paciente oncológico seja adequadamente avaliado, incluindo as etapas de diagnóstico, estadiamento, avaliação de resposta e seguimento, com impacto positivo na qualidade de vida e taxa de sobrevida.

Ecografía Doppler color en dermatología / Color Doppler ultrasound in dermatology

El uso de la ecografía Doppler color en dermatología ha traspasado la etapa experimental alcanzando la práctica diaria dermatológica. Su utilización abarca una gran variedad de patologías, lo que incluye frecuentes tumores benignos y malignos, enfermedades inflamatorias, el estudio de la uña y el pelo entre muchas otras aplicaciones. Esta técnica por imágenes no invasiva requiere de equipamiento especial y operadores entrenados, estando sus ventajas y limitaciones ya descritas en la literatura. Su utilización también permite discriminar las patologías de origen dermatológico de frecuentes simuladores de enfermedades dermatológicas. La información anatómica detallada descrita por esta técnica no es posible deducir por la mera inspección visual de un clínico, por lo este método por imágenes permitiría ayudar a realizar diagnósticos más precoces y precisos.

The usage of Color Doppler ultrasound in dermatology has surpassed the experimental phase and has been included in the daily dermatologic practice. There is a wide range of applications of this imaging technique such as benign and malignant tumors, inflammatory diseases as well as the study of the nail and the scalp, among others. It requires special ultrasound equipment and trained operators, being their advantages and limitations already described in literature. The detailed anatomical information provided by this imaging technique cannot be deduced by the physical examination of a well-trained physician, therefore this imaging modality may support a more early and precise diagnosis.

Synthesis of (4-18FFluorophenyl)triphenylphosphonium as a Mitochondrial Voltage Sensor for PET / 핵의학분자영상

PURPOSE: Lipophilic cations including tetraphenylphosphonium (TPP) salts penetrate the hydrophobic barriers of the plasma and mitochondrial membranes, resulting in accumulation in mitochondria in response to the negative inner transmembrane potentials. The development of radiolabeled phosphonium cations as a noninvasive imaging agent may serve as a new molecular "voltage sensor" probe to investigate the role of mitochondria in the pathophysiology and diagnosis of cancer. MATERIALS AND METHODS: We have synthesized a reference compound (4-fluorophenyl)triphenylphosphonium (TPP) and a labeled compound [18F]TPP via two step nucleophilic substitution of no-carrier-added [18F]fluoride with the precursor, 4-iodophenyltrimethylammonium iodide, in the presence of Kryptofix-2.2.2 and K2CO3. RESULT: The reference compound (4-fluorophenyl)triphenylphosphonium (TPP) was synthesized in 60% yield. The radiolabeled compound [18F]TPP was synthesized in 10~15% yield. The radiochemical purity of the [18F]TPP was 95.57+/-0.51% (n=11). CONCLUSION: [18F]TPP was successfully synthesized that might have a potential to be utilized as a novel myocardial or cancer imaging agent for PET. However, it is required to improve the radiochemical yield to apply [18F]TPP in preclinical or clinical researches.