Ultrasound elastography is a noninvasive imaging modality used to assess the mechanical behavior of tissues, including cancers. Analytical and finite element (FE) models are useful and effective tools to understand the mechanical behavior of cancers and predict elastographic parameters under different testing conditions. A number of analytical and FE models to describe the mechanical behavior of cancers in elastography have been reported in the literature. However, none of these models consider the presence of solid stress (SS) inside the cancer, a clinically significant mechanical parameter with an influential role in cancer initiation, progression, and metastasis. In this paper, we develop an FE model applicable to cancers, which include both SS and elevated interstitial fluid pressure (IFP). This model is then used to assess the effects of these mechanical parameters on the normal strains and the fluid pressure, estimated using ultrasound poroelastography. Our results indicate that SS creates space-dependent changes in the strains and fluid pressure inside the tumor. This is in contrast to the effects produced by IFP on the strains and fluid pressure, which are uniformly distributed across the cancer. The developed model can help elucidating the role of SS on elastographic parameters and images. It may also provide a means to indirectly obtain information about the SS from the observed changes in the experimental elastographic images.

Photothermal therapy (PTT) has been emerging as an effective, minimally invasive approach to treat cancers. However, a method to quantitatively evaluate the treatment effect after laser-induced thermotherapy (LITT) is needed. In this study, we used 808 nm laser radiation with three different power densities to treat the breast cancer tissue from 4T1 cell lines in a mouse model. The viscoelastic properties of the treated cancer tissues were characterized by a two-term Prony series using a ramp-hold indentation method. We observed that instantaneous shear modulus G 0 was significantly higher for the treated cancer tissues than that of the untreated tissue when treated with a power density of 1.5 W/cm 2 , but significantly lower with a power density of 2.5 W/cm 2 . The long-term shear modulus G ∞ was also significantly higher for the cancer tissue at 1.5 W/cm 2 , compared to the untreated tissue. The treatment effects were verified by estimating the cell apoptosis rate using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). Our results indicate that the viscoelastic properties of the tissue could potentially be used as biomarkers for evaluating the LITT treatment effect. In addition, we also observed a strain-independent behavior of the treated cancer tissue, which provided useful information for applying in vivo imaging method such as magnetic resonance elastography (MRE) for treatment evaluation based on biomechanical properties.

Infrared (IR) breast thermography has been associated with the early detection of breast cancer (BC). However, findings in previous studies have been inconclusive. The upright position of subjects during imaging introduces errors in interpretation, because it blocks the optical access in the inframammary fold region and alters the temperature due to contact between breast and chest wall. These errors can be avoided by imaging breasts in prone position. Although the numerical simulations provide insight into thermal characteristics of the female breast with a tumor, most simulations in the past have used cubical and hemispherical breast models. We hypothesize that a breast model with the actual breast shape will provide true thermal characteristics that are useful in tumor detection. A digital breast model in prone position is developed to generate the surface temperature profiles for breasts with tumors. The digital breast model is generated from sequential magnetic resonance imaging (MRI) images and simulations are performed using finite volume method employing Pennes bioheat equation. We investigated the effect of varying the tumor metabolic activity on the surface temperature profile. We compared the surface temperature profile for various tumor metabolic activities with a case without tumor. The resulting surface temperature rise near the location of the tumor was between 0.665 and 1.023 °C, detectable using modern IR cameras. This is the first time that numerical simulations are conducted in a model with the actual breast shape in prone position to study the surface temperature changes induced by BC.

This paper presents the design evolution, fabrication, and testing of a novel patient and organ-specific, three-dimensional (3D)-printed phantom for external beam radiation therapy (EBRT) of prostate cancer. In contrast to those found in current practice, this phantom can be used to plan and validate treatment tailored to an individual patient. It contains a model of the prostate gland with a dominant intraprostatic lesion (DIL), seminal vesicles, urethra, ejaculatory duct, neurovascular bundles, rectal wall, and penile bulb generated from a series of combined T2-weighted/dynamic contrast-enhanced magnetic resonance (MR) images. The iterative process for designing the phantom based on user interaction and evaluation is described. Using the CyberKnife System at Boston Medical Center, a treatment plan was successfully created and delivered. Dosage delivery results were validated through gamma index calculations based on radiochromic film measurements which yielded a 99.8% passing rate. This phantom is a demonstration of a methodology for incorporating high-contrast MR imaging into computed-tomography-based radiotherapy treatment planning; moreover, it can be used to perform quality assurance (QA).

Novel imaging technologies continued to be introduced into the operative setting. In particular, novel image-enhanced laparoscopic techniques are being explored for use in gynecologic operations. This systematic review describes these technologies in four relevant areas of gynecologic surgery. The PubMed database was searched for human, English-language studies, and the reference lists of retrieved articles were reviewed. An analysis of pooled data from 34 studies that met inclusion criteria was performed. The results suggest that image-enhanced technology may be useful in several common gynecologic procedures. Auto- and drug-enhanced fluorescence laparoscopy allow for increased detection of nonpigmented endometriotic lesions. Using these technologies for peritoneal staging of ovarian malignancy is of uncertain benefit. Drug-enhanced fluorescence laparoscopy for sentinel lymph node (SLN) detection in patients with uterine or cervical malignancy is feasible, showing a high rate of SLN detection, but a low sensitivity of identifying metastases. Finally, their use in intra-operative visualization of the ureter is promising. The majority of available data was from feasibility studies with limited sample sizes. Nevertheless, the results described in this systematic review support the expectation that these upcoming image-enhanced laparoscopy techniques will play a more important role in the future care of gynecologic patients.