Warner Prevoo

The significance of circumscribed malignant mammographic masses in the surveillance of BRCA 1/2 gene mutation carriers

Breast cancers in gene mutation carriers may escape mammographic detection because of rapid growth and tumor expansion. Therefore, they may mimic benign lesions on the mammogram. Twenty-nine BRCA 1/2 mutation carriers under surveillance developed 31 breast cancers between 1994 and 2001 at a mean age of 44.2 years. Controls were 63 women with 67 breast cancers in the same period at a mean age of 53.8 years, also under surveillance because of a life time risk of at least 15%. In 26% of the carriers vs. 48% of the controls, mammography was the method that first suspected a malignancy. Seven radiologists performed a retrospective review of the original mammograms to establish technical assessment, with special attention for circumscribed lesions and estimated probability of malignancy. In the mutation carriers seven (23%) circumscribed non-calcified mammographic masses were found and three in the controls (4.5%) P=0.01. These masses were proven to be malignant. In both groups around 70% of these fast-growing circumscribed lesions were detected by the patients. The masses were situated in breasts with a good interpretable breast pattern. BRCA 1/2 mutation carriers had a significantly higher percentage of circumscribed non-calcified mammographic masses that proved to be malignant. These mammographic lesions in women at high risk should be described as at least Birads 0 and worked-up with ultrasound and needle biopsy.

Radiofrequency Ablation for Treatment of Sporadic Angiomyolipoma

INTRODUCTION Symptomatic angiomyolipoma (AML) and asymptomatic AML larger than 4 cm in size are usually treated with nephron-sparing surgery or arterial embolization. We used another technique, that is, radiofrequency ablation (RFA), for treatment of a sporadic AML in a patient with a solitary kidney, in whom maximal sparing of normal renal tissue was required. TECHNICAL CONSIDERATIONS Contrast-enhanced computed tomography (CT) showed an enhancing well-defined mainly lipomatous tumor, with a maximum diameter of 4.5 cm in the upper pole of the left kidney. Diagnosis of AML was confirmed with fine-needle aspiration biopsy. RFA was performed with a RF 3000 system, consisting of a generator that supplied up to 200W of power, connected to a 15-gauge LeVeen multipolar array electrode that was placed under CT-guidance centrally in the AML. Initial power was set at low power and increased with increments of 10W, according to the algorithm provided by the manufacturer, resulting in a final tumor end temperature above 65 degrees C. No complications occurred and the patient was discharged home the day after. During follow-up (12 months) function of the solitary kidney of the patient was preserved and patient did not have any AML-related symptoms develop. Contrast-enhanced CT scan showed complete (100%) tumor ablation with absence of enhancement in the tumor and decreased tumor size from 4.5 cm to 2.9 cm at 12 months. CONCLUSIONS CT-guided RFA is a minimally invasive ablation procedure that allowed successful treatment of a sporadic AML in a patient with a solitary kidney. No complications occurred and no AML recurrence was observed during the 12-month follow-up.

Radiofrequency ablation as a treatment tool for liver metastases of colorectal origin

Abstract At diagnosis 10–25% of patients with colorectal liver metastases (CRLM) present as resectable disease. Liver resection is the gold standard treatment, resulting in a 5-year overall survival (OS) of 22–58%, local recurrence rates of 1.2–10.4% and a perioperative mortality of less than 5%. Multiple attempts have been made to assess the possible contribution of radiofrequency ablation (RFA) to improve OS and progression-free survival (PFS) in patients with unresectable colorectal liver metastases. The aim of this paper is to review the RFA literature in the setting of colorectal liver metastases: RFA with and without chemotherapy, RFA with and without resection, RFA for solitary unresectable CRLM, surgical and percutaneous imaging-guided RFA, RFA compared with chemotherapy. The reported OS, PFS, local recurrence rates, morbidity and mortality in these different settings are analyzed. This paper reflects on a possible role of RFA in resectable CRLM.

Probability of Downsizing Primary Tumors of Renal Cell Carcinoma by Targeted Therapies Is Related to Size at Presentation

OBJECTIVE To evaluate the probability of downsizing primary renal tumors by targeted therapy in correlation to size. METHODS A literature search was conducted and our own data were pooled with data of retrospective series and prospective trials in which patients were treated with tyrosine kinase inhibitors (TKIs) and in which tumor sizes before and after treatment were reported. Included were 89 primary clear cell renal tumors, including 34 from our institutes. The longest diameter of the primary tumors before and after treatment was obtained. Primary tumor size at presentation was divided in 4 categories: <5 cm (n=10), 5 to 7 cm (n=21), 7 to 10 cm (n=31), and >10 cm (n=27). Pearson correlation and t test were used for statistical analysis. RESULTS The TKI was sorafenib in 21 tumors and sunitinib in the remaining 68. Smaller tumor size was related to more effective downsizing (P=0.01). Median downsizing was 32% (-46% to 11%) in the first group (<5 cm) and 11% (-55% to 16%) in the second group (5-7 cm); however, 8 of 21 (38%) in this group reduced to a range of 2.3 to 4.7 cm in which ablative techniques are feasible and nephron-sparing surgery may benefit from the reduced size. Median downsizing was 18% (-39% to 2%) in tumors of 7 to 10 cm and 10% (-31% to 0%) in those>10 cm. CONCLUSION The smaller the primary tumor, the greater the likelihood and the more effective the downsizing. A potential benefit of neoadjuvant treatment to downsize the primary tumor for ablative techniques or nephron-sparing surgery may exist, particularly in tumors sized 5 to 7 cm.

Real-time in vivo tissue characterization with diffuse reflectance spectroscopy during transthoracic lung biopsy: a clinical feasibility study

Purpose: This study presents the first in vivo real-time tissue characterization during image-guided percutaneous lung biopsies using diffuse reflectance spectroscopy (DRS) sensing at the tip of a biopsy needle with integrated optical fibers. Experimental Design: Tissues from 21 consented patients undergoing lung cancer surgery were measured intraoperatively using the fiber-optic platform capable of assessing various physical tissue properties highly correlated to tissue architecture and composition. In addition, the method was tested for clinical use by performing DRS tissue sensing during 11 routine biopsy procedures in patients with suspected lung cancer. Results: We found that water content and scattering amplitude are the primary discriminators for the transition from healthy lung tissue to tumor tissue and that the reliability of these parameters is not affected by the amount of blood at the needle tip. In the 21 patients measured intraoperatively, the water-to-scattering ratio yielded a 56% to 81% contrast difference between tumor and surrounding tissue. Analysis of the 11 image-guided lung biopsy procedures showed that the tissue diagnosis derived from DRS was diagnostically discriminant in each clinical case. Conclusions: DRS tissue sensing integrated into a biopsy needle may be a powerful new tool for biopsy guidance that can be readily used in routine diagnostic lung biopsy procedures. This approach may not only help to increase the successful biopsy yield for histopathologic analysis, but may also allow specific sampling of vital tumor tissue for genetic profiling. Clin Cancer Res; 22(2); 357–65. ©2015 AACR. See related commentary by Aerts, p. 273

Local progression after radiofrequency ablation for pulmonary metastases

Local treatment for pulmonary metastases is considered to be a reasonable treatment option in patients with oligometastatic disease. Percutaneous radio frequency ablation (RFA) has been reported as an alternative to surgery. Results of RFA for local control of pulmonary metastases were evaluated.

Diffuse reflectance spectroscopy: toward real‐time quantification of steatosis in liver

Assessment of fatty liver grafts during orthotopic liver transplantation is a challenge due to the lack of real‐time analysis options during surgery. Diffuse reflectance spectroscopy (DRS) could be a new diagnostic tool to quickly assess steatosis. Eight hundred and seventy‐eight optical measurements were performed in vivo in 17 patients in liver tissue during surgery and ex vivo on liver resection specimens from 41 patients. Liver steatosis was quantified from the collected optical spectra and compared with the histology analysis from the measurement location by three independent pathologists. Twenty two patients were diagnosed with <5% steatosis, 15 patients had mild steatosis, and four had moderate steatosis. Severe steatosis was not identified. Intraclass correlation between the pathologists analysis was 0.949. A correlation of 0.854 was found between the histology and DRS analyses of liver steatosis ex vivo. For the same liver tissue, a correlation of 0.925 was demonstrated between in vivo and ex vivo DRS analysis for steatosis quantification. DRS can quantify steatosis in liver tissue both in vivo and ex vivo with good agreement compared to histopathology analysis. This analysis can be performed real time and may therefore be useful for fast objective assessment of liver steatosis in liver surgery.

Radiofrequency ablation of kidney tumours in patients with a solitary kidney.

Radiofrequency ablation of kidney tumours in patients with a solitary kidney W. Prevoo , M.P. van den Munckhof , W. Meinhardt , S. Horenblas , M.A.A.J. van den Bosch c,* a Department of Radiology, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands b Department of Urology, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands c Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands

Monitoring of tumor radio frequency ablation using derivative spectroscopy.

Abstract. Despite the widespread use of radio frequency (RF) ablation, an effective way to assess thermal tissue damage during and after the procedure is still lacking. We present a method for monitoring RF ablation efficacy based on thermally induced methemoglobin as a marker for full tissue ablation. Diffuse reflectance (DR) spectra were measured from human blood samples during gradual heating of the samples from 37 to 60, 70, and 85°C. Additionally, reflectance spectra were recorded real-time during RF ablation of human liver tissue ex vivo and in vivo. Specific spectral characteristics of methemoglobin were extracted from the spectral slopes using a custom optical ablation ratio. Thermal coagulation of blood caused significant changes in the spectral slopes, which is thought to be caused by the formation of methemoglobin. The time course of these changes was clearly dependent on the heating temperature. RF ablation of liver tissue essentially led to similar spectral alterations. In vivo DR measurements confirmed that the method could be used to assess the degree of thermal damage during RF ablation and long after the tissue cooled.

In vivo tumor identification of colorectal liver metastases with diffuse reflectance and fluorescence spectroscopy

Over the last decade, an increasing effort has been put towards the implementation of optical guidance techniques to aid surgeons during cancer surgery. Diffuse reflectance spectroscopy (DRS) and fluorescence spectroscopy (FS) are two of these new techniques. The objective of this study is to investigate whether in vivo optical spectroscopy is able to accurately discriminate colorectal liver metastases (CRLM) from normal liver tissue in vivo.