Mikio Shiozawa

SENTINEL NODE DETECTION METHOD USING CONTRAST-ENHANCED ULTRASONOGRAPHY WITH SONAZOID IN BREAST CANCER: PRELIMINARY CLINICAL STUDY

This study aimed to evaluate the usefulness of sentinel lymph node (SLN) detection in breast cancer using contrast-enhanced ultrasonography (CEUS) with subareolar Sonazoid injection. The subjects were 20 breast cancer patients. General anesthesia was induced and 2 mL of Sonazoid was injected subareolarly. After massage of the injection site, the axillary area was observed transdermally using coded phase inversion harmonic ultrasonography with mechanical indices of 0.15 to 0.19. When contrast-enhanced lymph nodes (LNs) were seen, they were defined as CE-SLN. Two other SLN detection methods, the gamma-probe-guided and dye-guided methods, were performed together. We evaluated the SLNs detected by each method to determine if they corresponded with each other and calculated the SLN detection rate. After the SLNs were resected, pathologic examinations were done. The SLN detection rate of the CEUS-guided method, the dye-guided method and the gamma-probe-guided method were 70%, 75% and 100%, respectively. There was no statistically significant difference in these rates between the CEUS-guided and dye-guided methods (p = 0.99) but the CEUS-guided method showed a significantly lower rate than the gamma-probe-guided method (p = 0.020), and dye-guided method also showed a significantly lower rate than the gamma-probe-guided method (p = 0.047). The number of CE-SLNs was 1 or 2 (average 1.1) and each took 2 to 20 (average 5.3) min to detect. The CE-SLNs corresponded grossly with SLNs detected by the gamma-probe-guided and dye-guided methods. The pathologic results indicated no metastasis from the resected SLNs in 15 of 20 cases. However, the CEUS-guided method detected 12 cases of these 15 and CE-SLNs were detected in two of the remaining five metastasis cases. In summary, in breast cancer patients, after subareolar injection of Sonazoid, contrast-enhanced LNs were observed in real time with ultrasonography. In an initial clinical study of 20 cases, the detection rate of the CEUS-guided method was less than that of the gamma-probe-guided method. It is suggested that the CEUS-guided method using Sonazoid may, with some improvements, be a useful new modality for sentinel node identification.

Sentinel lymph node biopsy in patients with breast cancer using superparamagnetic iron oxide and a magnetometer

BackgroundSome hospitals lack facilities for radioisotopes in sentinel node biopsy. A novel method is used with a superparamagnetic tracer and a magnetometer instead of a radioisotope.MethodsThirty patients were included in the study after obtaining IRB approval. Superparamagnetic iron oxide and patent blue dye were injected in the subareolar breast tissue. Following a few minutes of massage to promote migration of the iron tracer and blue dye throughout the lymphatic vessels, the axillary lymph nodes were detected transdermally using a handheld magnetometer and followed by standard axillary dissection in all patients.ResultsOf 30 patients evaluated, sentinel lymph nodes were identified in 90% (27/30) using both blue dye and magnetic tracer. Sentinel lymph nodes were identified using the magnetic method in 23/30 (77%) and blue dye in 24/30 (80%). There was one false-negative sentinel node, resulting in an overall sensitivity of 6/7 (86%).ConclusionsThis is the first study to use a magnetic tracer to identify sentinel lymph nodes in patients with breast cancer. This new technique may alter the role of radioisotopes with further refinement and experience.

Preoperative virtual simulation of adrenal tumors

BackgroundRetroperitoneal endoscopic adrenalectomy (EA) is recognized as a principal procedure for benign adrenal tumors. However, a limited visual field and a narrow working space make this approach difficult, particularly in cases of obese patients or small tumors. Using multidetector row CT (MD-CT), this study investigated the use of preoperative virtual simulation (PVS) to identify tumor and central vein locations for EA, and verified these findings during EA surgery.Patients and methodsThe study enrolled 11 cases comprising 10 adrenal adenomas and one ACTH-independent macronodular adrenal hyperplasia admitted to Jichi Medical University Hospital, Tochigi, Japan, between November 2003 and October 2006. Patients were evaluated in a lateral bending position using MD-CT. 3D PVS images of ribs, vertebrae, kidneys, and adrenal tumors were generated and compared with real images obtained during EA. ResultsThe PVS images clearly showed the relative locations of the adrenal tumor, kidney, and adjacent anatomical structures. These locations were verified during EA. The central vein was identified in the PVS images in all cases. Information derived from the PVS images assisted in the performance of EA surgery.Conclusions Preoperative 3D-simulation images using MD-CT contributed to the safety and efficiency of performing EAs.

Retroperitoneal hand-assisted laparoscopic surgery for endoscopic adrenalectomy.

Although hand-assisted laparoscopic surgery (HALS) is very common in various laparoscopic procedures, it is rarely used for retroperitoneal endoscopic adrenalectomy because of the small working area. The authors evaluate HALS in endoscopic adrenalectomy with respect to its use as a rescue procedure in complicated cases. In their department, 47 patients underwent endoscopic adrenalectomies between 1998 and 2004. Mainly because of complicated anatomy, three primary aldosteronism cases were converted to retroperitoneal HALS. This involved making an additional 6 cm skin incision, into which the surgeon’s left hand was inserted, with the palm used to create a sufficient visual field and working area. The fingers were used for tactile sensation and blunt resection. For these three cases, successful retroperitoneal HALS in endoscopic adrenalectomy resulted in no mortality or morbidity. These findings indicate that this procedure is a feasible technique for complicated benign adrenal tumor cases.

A magnetic probe equipped with small-tip permanent magnet for sentinel lymph node biopsy

We previously developed a magnetic probe equipped with a ring-shaped permanent magnet for detecting magnetic nanoparticle tracer accumulating in the sentinel lymph nodes (SLNs). The magnetic probe enables us to identify SLNs objectively, without the risk of radiation exposure, unlike the conventional technique using dye and radioisotope. A technical challenge of the probe is to reduce the tip diameter of magnet to identify smaller SLNs. In this study, we optimized the size of smaller-tip magnet based on numerical analyses using the finite element method and evaluated the expected sensitivity. According to the analysis results, the optimum tip diameter and length of convex-shaped magnet were 16 mm and 12 mm, respectively. The experimental results showed that the sensitivity of the probe with smaller-tip magnet was comparable to the previous one. We successfully developed a smaller tip magnet, maintaining the sensitivity to magnetic nanoparticles. The proposed probe will be capable of identifying the locati...

Partial duplication of MSH2 spanning exons 7 through 14 in Lynch syndrome

BackgroundLynch syndrome, also referred to as hereditary nonpolyposis colorectal cancer, is the most common form of hereditary colorectal cancer, and is associated with a high incidence of multiple primary neoplasms in various organs.MethodsA 79-year-old woman (patient 1) diagnosed with ascending colon cancer had a history of previous carcinomas of the uterus, stomach, uroepithelial tract, and colon. One year later, she developed a brain tumor (glioblastoma). A 54-year-old female (patient 2) was diagnosed with endometrial cancer and sigmoid colon cancer. Both patients underwent genetic evaluations independently.ResultsNo mutations were found in an exon-by-exon analysis of genomic DNA by polymerase chain reaction (PCR) and reverse transcription (RT)-PCR. However, multiplex ligation-dependent probe amplification (MLPA) identified genomic duplication spanning from exon 7 to exon 14 of the MSH2 gene in both patients. Due to the presence of this characteristic gene duplication, their pedigrees were investigated further, and these showed that they are paternal half-sisters, consistent with paternal inheritance.ConclusionLarge genomic duplication from intron 6 through intron 14 in MSH2 is a very rare cause of Lynch syndrome and is difficult to identify with conventional methods. MLPA may be an alternative approach for detecting large-scale genomic rearrangements.

Spontaneous Regression of Pulmonary Metastases from a Malignant Phyllodes Tumor

We report a case of spontaneous regression of pulmonary metastases from a malignant phyllodes tumor. A 50-year-old woman was diagnosed with a breast phyllodes tumor. Computed tomography and positron emission tomography revealed multiple lung metastases. She underwent a mastectomy to control the pain of the enlarging breast mass. Histopathologic examination diagnosed a malignant phyllodes tumor. Without the administration of any adjuvant therapy, the follow-up chest computed tomography scan and positron emission tomography scan showed disappearance of the lung metastases 2 months after surgery.

Handheld magnetic probe with permanent magnet and Hall sensor for identifying sentinel lymph nodes in breast cancer patients

The newly developed radioisotope-free technique based on magnetic nanoparticle detection using a magnetic probe is a promising method for sentinel lymph node biopsy. In this study, a novel handheld magnetic probe with a permanent magnet and magnetic sensor is developed to detect the sentinel lymph nodes in breast cancer patients. An outstanding feature of the probe is the precise positioning of the sensor at the magnetic null point of the magnet, leading to highly sensitive measurements unaffected by the strong ambient magnetic fields of the magnet. Numerical and experimental results show that the longitudinal detection length is approximately 10 mm, for 140 μg of iron. Clinical tests were performed, for the first time, using magnetic and blue dye tracers—without radioisotopes—in breast cancer patients to demonstrate the performance of the probe. The nodes were identified through transcutaneous and ex-vivo measurements, and the iron accumulation in the nodes was quantitatively revealed. These results show that the handheld magnetic probe is useful in sentinel lymph node biopsy and that magnetic techniques are widely being accepted as future standard methods in medical institutions lacking nuclear medicine facilities.