Joost M. Klaase

Initial results of in vivo non-invasive cancer imaging in the human breast using near-infrared photoacoustics.

Near-infrared photoacoustic images of regions-of-interest in 4 of the 5 cases of patients with symptomatic breasts reveal higher intensity regions which we attribute to vascular distribution associated with cancer. Of the 2 cases presented here, one is especially significant where benign indicators dominate in conventional radiological images, while photoacoustic images reveal vascular features suggestive of malignancy, which is corroborated by histopathology. The results show that photoacoustic imaging may have potential in visualizing certain breast cancers based on intrinsic optical absorption contrast. A future role for the approach could be in supplementing conventional breast imaging to assist detection and/or diagnosis.

Visualizing breast cancer using the Twente photoacoustic mammoscope: what do we learn from twelve new patient measurements?

We acquired images of breast malignancies using the Twente photoacoustic mammoscope (PAM), to obtain more information about the clinical feasibility and limitations of photoacoustic mammography. Results were compared with conventional imaging and histopathology. Ten technically acceptable measurements on patients with malignancies and two measurements on patients with cysts were performed. In the reconstructed volumes of all ten malignant lesions, a confined region with high contrast with respect to the background could be seen. In all malignant cases, the PA contrast of the abnormality was higher than the contrast on x-ray mammography. The PA contrast appeared to be independent of the mammographically estimated breast density and was absent in the case of cysts. Technological improvements to the instrument and further studies on less suspicious lesions are planned to further investigate the potential of PAM.

Factors Influencing the Local Failure Rate of Radiofrequency Ablation of Colorectal Liver Metastases

BackgroundThe prognosis of patients with colorectal cancer is poor, especially when there is distant metastatic disease. Local ablation of tumor by radiofrequency ablation (RFA) has emerged as a safe and effective new treatment modality, but its long-term efficacy may be hindered by renewed local tumor growth at the site of RFA. The objectives of this study were to identify risk factors for local RFA failure and to define exclusion criteria for RFA treatment of colorectal liver metastases.MethodsA total of 199 lesions in 87 patients were ablated with RFA. Factors influencing local failure rates were identified and compared with data from the literature.ResultsThe local failure rate was 47.2%, and the average time to local disease progression was 6.5 months. Factors that significantly correlated with increased failure rates were metachronous occurrence of liver metastases, large mean lesion size, and central tumor location.ConclusionsBecause accurate electrode placement is pivotal in achieving adequate tumor necrosis, RFA should not be performed percutaneously when electrode placement is impaired. We suggest that lesions >5 cm and lesions located near great vessels or adjacent organs should be treated with open RFA, thus allowing vascular inflow occlusion and complete mobilization of the liver. Lesions that are difficult to reach by electrodes should be approached by an open procedure.

Photoacoustic image patterns of breast carcinoma and comparisons with Magnetic Resonance Imaging and vascular stained histopathology

Photoacoustic (optoacoustic) imaging can visualize vasculature deep in tissue using the high contrast of hemoglobin to light, with the high-resolution possible with ultrasound detection. Since angiogenesis, one of the hallmarks of cancer, leads to increased vascularity, photoacoustics holds promise in imaging breast cancer as shown in proof-of-principle studies. Here for the first time, we investigate if there are specific photoacoustic appearances of breast malignancies which can be related to the tumor vascularity, using an upgraded research imaging system, the Twente Photoacoustic Mammoscope. In addition to comparisons with x-ray and ultrasound images, in subsets of cases the photoacoustic images were compared with MR images, and with vascular staining in histopathology. We were able to identify lesions in suspect breasts at the expected locations in 28 of 29 cases. We discovered generally three types of photoacoustic appearances reminiscent of contrast enhancement types reported in MR imaging of breast malignancies, and first insights were gained into the relationship with tumor vascularity.

Anterior resection of rectal cancer without bowel preparation and diverting stoma

PurposeSince the introduction of total mesorectal excision (TME) as the standard operation technique for rectal cancer, anastomotic leakage percentages of up to 18% have been reported. To prevent such leakage, the use of mechanical bowel preparation and also the construction of a diverting ileostoma or colostomy have been standard procedures for years. In our institute, however, all patients undergoing colorectal surgery are operated upon without these measures. The present study was undertaken to investigate the results of this strategy in terms of the occurrence of postoperative anastomotic leakage.MethodsAll patients who underwent an elective (low) anterior resection between January 1996 and December 2001 (n = 144) entered the study. The clinical and pathological records of these patients were reviewed retrospectively. The exclusion criteria were patients with fixed rectal carcinoma who received preoperative radiotherapy and/or a stoma only at operation, emergency operations, abdominoperoneal resections, and Hartmann’s procedures.ResultsAnastomotic leakage occurred in 7 out of 144 patients (4.9%). There was a trend toward a higher leakage frequency in men, in patients with a distal anastomosis, in patients with a stapled anastomosis, and in patients with a T3–T4 tumor or with positive lymph nodes. None of these factors, however, had a significant prognostic value based on a univariate or multivariate analysis. Those who died after leakage tended to be older than those who did not (P < 0.05).ConclusionA (low) anterior resection can be performed safely without mechanical bowel preparation or a diverting stoma, and results in an anastomotic leakage percentage of less than 5%. Appropriate selection of patients may be important, but none of the investigated patient- or tumor-related factors could be identified as decisive.

Fibrin Sealant for Prevention of Resection Surface-Related Complications After Liver Resection: A Randomized Controlled Trial

Objective:To evaluate the efficacy of fibrin sealant in reducing resection surface-related complications in liver surgery. Background:Bile leakage, bleeding, and abscess formation are major resection surface-related complications after liver resection. It is unclear whether application of fibrin sealant to the resection surface is effective in reducing these complications. Methods:In a multicenter, randomized trial in 310 noncirrhotic patients undergoing liver resection, we compared prophylactic application of fibrin sealant to the resection surface (156 patients) with no application of fibrin sealant (154 patients). In addition to clinical assessments, patients underwent protocolized computerized tomography (CT) scan 1 week postoperatively. Primary endpoint was a composite of postoperative resection surface-related complications (bile leakage, bleeding, or abscess), as adjudicated by a clinical-events committee that was unaware of the study-group assignments. Results:Overall rate of resection surface-related complications was not different between the 2 groups: 24% (38/156 patients) in the fibrin sealant group and 24% (37/154 patients) in the control group. Bile leakage was detected in 14% of patients in the fibrin sealant group and in 14% of controls. CT scans showed a fluid collection at the resection surface 100 mL or more in 28% of patients in the fibrin sealant group and in 26% of controls (P = 0.800). The rate of reinterventions for resection surface-related complications (12% vs 10%; P = 0.492) and severity of complications did also not differ between the 2 groups. Conclusions:This randomized multicenter trial shows that prophylactic application of fibrin sealant at the resection surface after liver resections does not lead to a reduction in the incidence or severity of postoperative bile leakage or other resection surface-related complications (Controlled trial number, ISRCTN85205641).

Validation of the Dutch functional, communicative and critical health literacy scales

OBJECTIVE While most existing health literacy (HL) measures focus primarily on reading comprehension, the functional, communicative and critical HL scales from Ishikawa et al. [19] aim to measure a broader HL spectrum. The objective of this study was to evaluate the validity of the Dutch translation of this instrument. METHODS Two survey studies (n = 79 and n = 209) and one cognitive interview study (n = 18) were performed among samples of breast cancer patients and patients with rheumatic diseases. RESULTS Analyses showed the scales measured three distinct factors and convergent validity was satisfactory for communicative and critical HL. Nevertheless, the comprehension of the items and the suitability of the response options raised some problems. CONCLUSION The HL scales seem promising to measure a broad definition of HL. By revising some of the items and response options as proposed in this article, the scale will become more understandable for people with low HL skills, which might increase the content validity and the distributional properties of the scale. PRACTICE IMPLICATIONS The scale should be revised and revalidated. An improved version should be used in practice to gain insight into HL levels of patients. This will help to develop suitable education programs for people with low HL skills.

Imaging Tumor Vascularization for Detection and Diagnosis of Breast Cancer

Breast cancer is one of the major causes of morbidity and mortality in western women. Current screening and diagnostic imaging modalities, like x-ray mammography and ultrasonography, focus on morphological changes of breast tissue. However, these techniques still miss some cancers and often falsely detect cancer. The sensitivity and specificity for detecting the disease can probably be improved by focusing on the consequences of tumor angiogenesis: the increased microvessel density with altered vascular characteristics. In this review, various techniques for imaging breast tumor vasculature are discussed. Dynamic contrast enhanced magnetic resonance imaging is the most-used imaging modality in this field. It has a proven high sensitivity, but a low specificity and cannot be applied in all women. Moreover, it has problems with detecting ductal carcinoma in situ (DCIS). On the contrary, contrast enhanced digital mammography can detect DCIS, but requires the use of ionizing radiation. Contrast enhanced ultrasound provides real-time information about true intravascular blood volume and flow. However, this technique still has difficulties with discriminating benign from malignant tissue. Moreover, these three imaging modalities all require the injection of contrast agents. Two relatively new techniques that do not use external contrast agents are diffuse optical imaging and photoacoustic imaging. Both visualize the increased concentration of hemoglobin in malignant tissue and thereby provide a high intrinsic contrast.

Meta-analysis of superficial versus deep injection of radioactive tracer and blue dye for lymphatic mapping and detection of sentinel lymph nodes in breast cancer

Sentinel lymph node biopsy (SLNB) is the standard of care for axillary staging in early breast cancer. Currently, no consensus exists on the optimal site of injection of the radioactive tracer or blue dye.

Local recurrence of rectal cancer after total mesorectal excision without preoperative radiotherapy.

AbstractBackground: At this moment, it is still debatable whether all patients with mobile rectal cancer who undergo surgical removal of the tumor should be treated with preoperative radiotherapy, since it is likely that only certain patients will benefit from this strategy. In this study, patients with mobile rectal cancer were immediately operated upon and only those with positive nodes or with incomplete resection received adjuvant radiotherapy. Aims of the Study: To investigate the local recurrence rate after the use of a selective policy of adjuvant radiotherapy and to determine risk factors for local recurrence. Methods: In a 5-yr-period, 178 patients with rectal cancer were referred to our institute. A total of 131 patients with mobile rectal cancer were treated with curative intent, which implied a microscopically radical resection and no signs of distant metastasis at operation. A retrospective analysis was undertaken to investigate the incidence of local recurrence in this curative group and to determine risk factors for local recurrence. Results: The postoperative mortality in the curative group was 5.3%. Local recurrences were observed in 6 patients (4.6%) after a median period of 25 mo (range 11–37); two of them also had distant metastases detected at the same time. The highest local recurrence rates were seen in men (5.3%), in distal rectal cancers (6.9%), and in the node-positive group (8.7%). Conclusion: A low local recurrence rate can be achieved after total mesorectal excision (TME) without preoperative radiotherapy. Our results suggest using preoperative radiotherapy only for those patients who are at a higher risk for local recurrence. Staging techniques for selection of these patients are at this moment still inappropriate.