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Hirofumi Fujii

Publications and source records attributed to Hirofumi Fujii.

31 records · Page 2Linked to original sources
PubMed2004

Lymphoscintigraphy for the visualization of sentinel lymph nodes and body contour.

BACKGROUND: It is important to create clear lymphoscintigraphic images when assessing the sentinel lymph nodes. This clarity needs to reach a level where the sentinel lymph nodes (SLNs) and the body contour are clearly visible. We have developed a simple image processing method using the division of primary and scattered photon counts. METHODS: Twenty patients with breast cancer were enrolled in this study. Manual injection of 150 MBq of Tc-99m tin colloid with small particle size into the peritumoral and subdermal regions was performed. Lymphoscintigraphy using a conventional gamma camera was performed three hours after the injection. Dual energy windows were set from 130 to 150 keV for the primary photons and 70 to 110 keV for the scattered photons. An anterior view of the chest and a lateral view from the affected side were obtained. Primary photon image counts were divided by the scattered photon image counts for each pixel after the addition of some constant counts to each pixel of the acquired image to improve the contrast of the scintigrams. We evaluated the ability to accurately visualize the body contour and the SLNs on the processed image. RESULTS: Image processing time was 20 to 40 seconds for each patient. In every case, the processed image clearly identified the body contour. The processed images allowed the identification of the same number of SLNs as the original images. CONCLUSIONS: This proposed method for image processing is a simple and useful means to clearly visualize both SLNs and body contours.

Adult↗
PubMed2004

Sentinel nodes of malignancies originating in the alimentary tract.

The feasibility of the sentinel node concept for malignancies originating in the alimentary tract is attracting much interest among researchers in the field of gastrointestinal oncology. We have tested more than 350 such cases and obtained favorable and promising initial results. The detectability of sentinel nodes using endoscopically injected Tc-99m tin colloid for these tumors exceeded 90%. Although the false negative ratio was not so low (approximately 10%), most of these cases had an inaccurate preoperative evaluation of mural invasion and/or a technically unfavorable injection. When the indication is restricted to patients with early-stage disease, and when the radioactive colloid is properly administered, sentinel node navigation therapy would be applicable for gastrointestinal malignancies. To achieve successful sentinel node navigation surgery it is essential to accurately identify sentinel nodes, and lymphoscintigraphy is a very useful test to confirm the location of sentinel nodes preoperatively. However, image processing is required for lymphoscintigrams because the original image depicts only high activity at the injection site and faint radioactivity in the sentinel nodes. We have clearly imaged the silhouette of the body using Compton scattered photons, and have also proposed several methods to improve the contrast between the injection sites and sentinel nodes. Many sentinel nodes can be clearly visualized by subtraction of the background activity with heterogeneous distribution. The development of the portable gamma camera, enabling intraoperative imaging, also contributes to less invasive biopsy of sentinel nodes. We have obtained promising initial results using a portable imaging device with semiconductor detectors. These promising results suggest that sentinel node navigation therapy including radiotherapy will be a new therapy for early-stage gastrointestinal malignancies in the near future, with nuclear medicine contributing to the establishment of new, less invasive therapies for gastrointestinal cancer.

Colorectal Neoplasms↗
PubMed2004

Recent development of sentinel lymph node biopsy for breast cancer in Japan.

The number of breast cancer cases undergoing sentinel lymph node biopsy (SLNB) has been increasing with the number of articles published in Japan. SLNB using the dye method alone is performed in about one-third of patients. Analysis of questionnaire responses from 40 institutions in Japan revealed an identification rate by the dye method alone of 87%, compared with 96% using the combined method; the combined method is now recognized in Japan as superior to the dye method alone. No dyes have been specifically approved by the government for use in SLNB, and physicians have been using several inappropriate dyes as tracers for SLNB, such as indocyanine green, patent blue, indigo carmine, and isosulfan blue. The colloidal radiotracers used in Japan include tin colloid, stannous phytate, rhenium sulfate and human serum albumin. Albumin colloid and sulfur colloid are not commercially available in Japan. Small-size tin colloids, stannous phytate and rhenium sulfate all yield good results in terms of detection and false-negative rates. Provided that the surgeon has adequate experience in SLNB, a negative sentinel node can serve as a substitute for negative results from axillary lymph node dissection. Although many institutions have introduced SLNB, few reports have focused on the results of SLNB without axillary dissection because of short follow-up times and small number of patients. The final decision as to whether SLNB is an adequate substitute for axillary dissection awaits the results of prospective randomized trials.

Axilla↗
PubMed2003

[Current status and future perspectives of sentinel node navigation surgery for esophageal cancer].

Esophageal cancer is a particularly aggressive malignancy because of the high incidence and widespread distribution of lymph node metastases. However, the sentinel node (SN) concept appears to be applicable even for esophageal cancer, according to recent reports. A dye-guided method is not applicable for esophageal cancer because of its anatomic site. It is impossible to trace the flow of blue dye within a certain observation time without destruction of the lymphatic network. SNs in esophageal cancer are multiple and their distribution is widely spread from the cervical to the abdominal area. Therefore the lymphoscintigram in the radio-guided method is essential to identify the SNs in esophageal cancer. Recently chemoradiotherapy has attracted attention as a multidisciplinary curative treatment for cT1N0 esophageal cancer. In this approach, control of invisible micrometases is essential. Lymphoscintigrams revealing the distribution of SNs in each individual case are useful to plan the field of irradiation. Selective and modified lymphadenectomy for clinical N0 esophageal cancer should become feasible and clinically useful. Individualized selective lymphadenectomy for cN0 esophageal cancer located in the esophagogastric junction including Barrett's carcinoma based on SN status would be a reasonable surgical approach.

Esophageal Neoplasms↗
PubMed2002

Can initial prostate specific antigen determinations eliminate the need for bone scans in patients with newly diagnosed prostate carcinoma? A multicenter retrospective study in Japan.

BACKGROUND: The objective of the current study was to assess rigorously whether serum prostate specific antigen (PSA) determination can eliminate the need for bone scans in Japanese patients with newly diagnosed prostate carcinoma with serum PSA levels < or = 10 ng/mL. METHODS: A retrospective assessment of 1294 patients with newly diagnosed, untreated prostate carcinoma was conducted at the authors' institutions. All patients underwent a bone scan, serum PSA measurement, and core needle biopsy of the prostate. The receiver operating characteristic curve for identifying a positive bone scan based on serum PSA levels and a decision tree were analyzed to determine the expected 10-year cumulative cost and disease specific survival rate. Two competing strategies were used: PSA alone and PSA plus baseline bone scan. For the PSA-alone strategy, a baseline bone scan was performed only when the patient had a serum PSA level > 10 ng/mL. RESULTS: The proportion of positive bone scans in patients with serum PSA levels < or = 10.0 ng/mL was 1.33%. The area under the receiver operating characteristic curve was 0.870. Patients with a Gleason Grade > or = 3 tumors or with a Gleason score > or = 7 had a higher proportion of positive bone scans. The 10-year disease specific survival rates with the PSA-alone strategy and the PSA-plus-bone-scan strategy were the same. The PSA-alone strategy was minimally cost effective, with a savings of $16.00 (U.S.) in the cumulative net cost per patient over the PSA-plus-bone-scan strategy. CONCLUSIONS: The current results suggest that baseline bone scans can be eliminated in patients with newly diagnosed prostate carcinoma in Japan who have serum PSA levels < or = 10 ng/mL. Apparently, it is possible to omit baseline bone scans for patients with a Gleason Grade < or = 2 tumors or with a Gleason score < or =6.

Adult↗
PubMed2002

Sentinel node mapping for colorectal cancer with radioactive tracer.

PURPOSE: The aim of this study was to test the feasibility and accuracy of radioactivity-guided mapping of the first lymph nodes found in draining the primary tumor site for colorectal cancer. METHODS: We enrolled 56 consecutive patients with preoperative diagnosis of curatively resectable colorectal cancer. Endoscopic injection of technetium Tc 99m-labeled tin colloid (15 MBq) was performed preoperatively, and radioactive sentinel nodes were identified intraoperatively with a gamma probe. Standard radical resection with lymph node dissection was performed in all patients, and all resected nodes were evaluated by routine histopathologic examination. RESULTS: Radioactivity-guided methods were used to detect sentinel nodes in 51 (91 percent) of 56 patients. The number of lymph nodes resected was 23.9 +/- 15.2 per case. The number of sentinel nodes was 3.5 +/- 2.1 (range, 0-8) per case. In 18 of 22 patients with lymph node metastasis, the sentinel node was positive. The incidence of metastasis in the sentinel node (22 percent) was significantly higher than that in nonsentinel nodes (3 percent, P < 0.01). Diagnostic accuracy according to sentinel node status was 92 percent (47/51). Four false-negative cases in this study were advanced cases with T3 primary tumors. The detection rate and diagnostic accuracy for patients with T1 or T2 primary tumors (29 cases) were 100 percent each. CONCLUSION: Intraoperative radioactivity-guided sentinel node mapping was accurate for patients with colorectal cancer with T1 or T2 tumors. The results suggest that sentinel node mapping and intraoperative biopsy may be a sensitive and specific diagnostic method for detecting metastasis in regional lymph nodes in patients with colorectal cancer.

Adult↗
PubMed2002

Sestamibi scintigraphy for the application of minimally invasive surgery of hyperfunctioning parathyroid lesions.

Complete surgical resection of hyperfunctioning parathyroid tissue is essential for the curative treatment of hyperparathyroidism. It is very important to identify the accurate location of the affected parathyroid glands by imaging tests to successfully achieve this surgical treatment. Tc-99m labeled sestamibi is a radiopharmaceutical with high affinity for endocrinologically active parathyroid tissue, and scintigraphic evaluation using this radioactive agent is very useful in confirming the location of the affected parathyroid glands. The recent remarkable development of hand-held gamma-ray detectors makes it easy to perform radio-guided surgery, which is a combination of a preoperative intravenous injection of sestamibi and intraoperative navigation by the gamma-rays radiating from the pathological sites. This strategy can be easily applied to the resection of the ectopically located gland and is also useful to confirm the absence of endocrinologically active tissue after the operation. Additional chest SPECT imaging might be effective in the risk assessment of cardiac incidence in the perioperative period, as sestamibi was originally developed for the evaluation of myocardial perfusion. In conclusion, Tc-99m sestamibi will be more popularly applied to the treatment of hyperparathyroidism as minimally invasive surgery increases in favor.

Animals↗
PubMed2002

Sentinel lymph node biopsy in breast cancer using technetium-99m tin colloids of different sizes.

Axillary lymph node dissection (ALND) in the treatment of breast cancer is essential for predicting the prognosis and regional control of the tumor. At the same time ALND is associated with pain, numbness and sometimes lymphedema. Sentinel lymph node biopsy (SLNB) is a potential alternative procedure to conventional ALND in clinically node-negative breast cancer. In this study, we prepared the technetium-99m-labeled tin colloids with different sizes and compared their efficacy in SLNB. From September 1998 to February 2002, 184 clinically node-negative breast cancer patients were enrolled in the study at Keio University Hospital. Sentinel lymph nodes (SLNs) were identified by both blue dye and radioisotope. We prepared small-sized technetium-99m-labeled tin colloid (particle size: 200-400 nm in diameter). Regular-sized technetium-99m-labeled tin colloid is 400-1000 nm in diameter. In 74 patients, a SLNB was performed using regular-sized tin colloid; small-sized tin colloid was used in 110 patients. Subsequently, all of the patients were immediately followed by ALND. All dissected lymph nodes were evaluated by routine histopathological examination. The clinicopathological characteristics of the two groups were comparable. The lymphoscintigram detected SLN more frequently in the small-sized colloid group than in the regular-sized colloid group (P < 0.01). Small-sized tin colloid was also superior to regular-sized tin colloid in the SLN identification rate (97.3% versus 86.5%; P = 0.01). The mean value for ex vivo counts of the hottest sentinel lymph nodes of the small-sized colloid group was significantly higher than the counts of the regular-sized colloid group (P < 0.01). There was no significant difference in the accuracy between the two groups. It was concluded that SLNB using the small-sized tin colloid was technically feasible and provided higher detection and identification rates than the regular-sized tin colloid.

Adult↗
PubMed2002

Intraoperative lymphatic mapping and sentinel lymph node sampling in esophageal and gastric cancer.

Recent studies for SN mapping of esophageal and gastric carcinoma show that the SN concept is valid even for upper GI cancers with multidirectional and complicated lymphatic flow. The relatively high incidence of anatomic skip metastasis can be attributed to aberrant distribution of SNs. An individualized and minimally invasive surgical approach can be applicable to management of esophageal and gastric carcinoma based on SN status. Although there are several issues to be resolved, this novel procedure has the potential for great benefit to improve quality control in the treatment of upper GI cancer. Well-designed clinical trials of lymphatic mapping for upper GI cancer will be essential to determine whether this technique is widely applicable in the management of these tumors.

Esophageal Neoplasms↗
PubMedDate not supplied

Adenoid cystic carcinoma with hyperostosis after stereotactic radiosurgery.

Adenoid cystic carcinoma (ACC) of the head and neck is a relatively rare tumor characterized by slow evolution, recurrences, and protracted clinical course. We performed stereotactic radiosurgery in order to palliate symptoms for intraorbital recurrence of ACC that had been treated with total resection of the left parotid gland, radical neck dissection, and conventionally fractionated radiotherapy. We experienced interesting hyperostosis in the area irradiated by the stereotactic radiosurgery.

Carcinoma, Adenoid Cystic↗