Advances in spatial resolution and radiation dose reduction using super-resolution deep learning-based reconstruction for abdominal computed tomography: A phantom study.

RATIONALE AND OBJECTIVES: This study evaluated the performance of super-resolution deep learning-based reconstruction (SR-DLR) and compared with it that of hybrid iterative reconstruction (HIR) and normal-resolution DLR (NR-DLR) for enhancing image quality in computed tomography (CT) images across various field of view (FOV) sizes, radiation doses, and noise reduction strengths. MATERIALS AND METHODS: A Catphan phantom equipped with an external body ring was used. CT images were reconstructed using filtered back-projection (FBP), HIR, NR-DLR, and SR-DLR across three noise reduction strengths: mild, standard, and strong. The noise power spectrum (NPS) was obtained from the FBP, HIR, NR-DLR, and SR-DLR images at various FOVs, radiation doses, and noise reduction strengths. The noise magnitude ratio (NMR) and central frequency ratio (CFR) were calculated from the HIR, NR-DLR, and SR-DLR images relative to the FBP images using NPS. The high-contrast value was obtained from the amplitude values of the peaks and valleys of profile curve and the task-based transfer function were also analyzed. RESULTS: SR-DLR consistently demonstrated superior noise reduction capabilities, with NMR of 0.29-0.36 at reduced dose and 0.35-0.45 at standard dose, outperforming HIR and showing comparable efficiency to NR-DLR. The high-contrast values for SR-DLR were highest at mild and standard levels for both low and standard doses (0.610 and 0.726 at mild and 0.725 and 0.603 at standard levels). At the standard dose, the spatial resolution of SR-DLR was significantly improved, regardless of the noise reduction strength and FOV. CONCLUSION: SR-DLR images achieved more substantial noise reduction than HIR and similar noise reduction as NR-DLR reconstructions while also improving spatial resolution.

Oncocytic adrenocortical neoplasm arising from adrenal rest in the broad ligament of the uterus.

Oncocytic adrenocortical neoplasm is characterized by abundant eosinophilic cytoplasm containing mitochondria, occasional nuclear atypia and diffuse growth pattern. Oncocytic adrenocortical neoplasm arising in adrenal rest is, however, extremely rare. We report a case of oncocytic adrenocortical neoplasm arising in adrenal rest of the broad ligament with associated marked lipomatous metaplasia. A well circumscribed tumor was accidentally detected in the pelvic cavity of a 29 year old Japanese woman, adjacent to the broad ligament of the uterus. The tumor was composed of large eosinophilic cells associated with diffuse growth pattern and abundant mature adipose tissue admixed with foci of clear cells. Both steroidgenic factor 1 (SF-1) and alpha-inhibin were immunohistochemically positive in tumor cells. Abundant mitochondria detected by immunohistochemical and electron microscopic examination confirmed the diagnosis of oncocytic adrenocortical neoplasm. The absence of necrosis, capsular and vascular invasion as well as the low mitotic index indicated the benign potential of this tumor. The tumor cells were also positive for dehydroepiandrosteron-sulfotransferase (DHEA-ST), 17ß-hydroxysteroid dehydrogenase type 5 (17ß-HSD5), 3ß-hydroxysteroid dehydrogenase (3ß-HSD) and steroid 17α-hydroxylase (P450-c17), suggesting a possible production of testosterone of this tumor. This is the first reported case of oncocytic adrenocortical adenoma arising in adrenal rest of the broad ligament.

Effects of eicosapentaenoic acid on biochemical failure after radical prostatectomy for prostate cancer.

AIM: To study the effects of eicosapentaenoic acid (EPA) on prostate-specific antigen (PSA) failure in prostate cancer patients who underwent prostatectomy. PATIENTS AND METHODS: Sixty-two prostate cancer patients whose PSA levels were less than 0.2 ng/ml 3 months after surgery were randomized to either an EPA group (n=32) or a control group (n=30). EPA (2.4 g/day) was administered in the EPA group for 2 years. PSA was measured every two months. RESULTS: The EPA concentration increased but the docosahexaenoic acid concentration decreased significantly (P<0.001) in erythrocytes. The PSA recurrence rates during a mean follow-up of 53.8 months were not different between the two groups (p=0.16). CONCLUSION: A longer and/or larger intervention or docosahexaenoic acid supplementation might be necessary to identify significant preventive effects of mega-3 polyunsaturated fatty acids on PSA recurrence.

The effect of eicosapentaenoic acid on prostate-specific antigen.

The "Study of EPA Effects on Prostate Cancer" (SEEPC) Group has been conducting a clinical trial with patients who underwent radical prostatectomy. The main purpose of the SEEPC is to evaluate whether eicosapentaenoic acid (EPA) prevents prostate cancer (PC) recurrence. As the surrogate marker of recurrence, the prostate-specific antigen (PSA) level was measured. However, if EPA affects the PSA values independently of PC, PSA may not be a good marker of recurrence in the event of EPA treatment. Thus, in the present study, whether EPA affected the PSA values was investigated using non-PC volunteers. Twenty men, of at least 50 years of age, were recruited, mostly from hospital staff The volunteers were randomly allocated either to the EPA group or the control. The subjects in the EPA group were administered EPA-ethyl ester a dose of 2400 mg/day for 12 weeks, whereas the controls were administered none. Fasting blood samples were obtained before the start of EPA administration and 4 and 12 weeks later. The EPA concentrations in erythrocytes increased in all the subjects in the EPA group (174+/-96%) with no significant changes in the control group (8.5+/-14.0%). There were no significant differences between the two groups in the serum PSA levels, allowing the conclusion that the PSA is an appropriate surrogate marker of recurrence in prostate cancer.

Laparoscopic partial versus total adrenalectomy for aldosterone producing adenoma.

PURPOSE: Laparoscopic surgery has become a standard method for adrenal treatment. Primary hyperaldosteronism is known to be frequently characterized by multiple adrenal lesions. The indication of laparoscopic partial or total adrenalectomy in patients with aldosterone producing adenoma (APA) remains controversial. We performed the 2 procedures and compared the outcomes of these 2 operations retrospectively. MATERIALS AND METHODS: A total of 92 patients with primary hyperaldosteronism were laparoscopically treated at our institution from 1995 to 2004. A total of 29 patients underwent partial adrenalectomy or enucleation, while unilateral total adrenalectomy was performed in 63. A single pathologist examined the number and histopathological characteristics of APAs. Postoperative median followup was 60.3 and 29.3 months, respectively. RESULTS: Laparoscopic adrenalectomies were successfully performed in each group, although the partial type had fewer ports and shorter operative time. All 63 patients with total adrenalectomy showed recovery from hypertension, suppressed plasma renin activity and high plasma aldosterone. Two of 29 patients with partial adrenalectomy or enucleation still experienced hypertension with high plasma aldosterone. Of the 63 extirpated specimens 17 adrenals (27.0%) demonstrated multiple space occupying lesions along with the main APA. CONCLUSIONS: Primary hyperaldosteronism is highly associated with multiple adrenal space occupying lesions. The risk-to-benefit ratio must be carefully weighed against the potential advantage of partial adrenalectomy. We chose total laparoscopic adrenalectomy in patients with unilateral APA and primary hyperaldosteronism.

Post-laminectomy long-term survival of a patient with spinal cord compression secondary to metastatic prostate cancer.

Spinal cord compression is a skeletal-related event in advanced malignancies and is associated with serious morbidity and poor prognosis. Despite the palliative nature of laminectomy treatment, it is important to prevent neurological deficits and relieve pain as a means to improve quality of life. Here we report on a prostate cancer patient with spinal cord compression who became ambulant from paraparesis after he underwent a decompression laminectomy; he survived for 9.5 years with good quality of life.

Lymphatic mapping and gamma probe guided laparoscopic biopsy of sentinel lymph node in patients with clinical stage I testicular tumor.

PURPOSE: We attempted to detect lymphatic drainage and sentinel lymph node with radioactive tracer in patients with testicular tumor. We then tried to determine if sentinel lymph node biopsy with gamma probe guided laparoscopic procedure was feasible as a staging tool for patients with clinical stage I testicular tumor. MATERIALS AND METHODS: Technetium-labeled phytate was injected around the tumor in 15 consecutive patients with clinical stage I testicular tumor. Lymphatic drainage and sentinel lymph nodes were imaged by a gamma camera. Localization of the sentinel lymph node was confirmed with a handheld gamma probe. After we confirmed that sentinel lymph nodes were detected in the initial 10 patients, gamma probe guided laparoscopic sentinel lymph node biopsy was performed after routine orchiectomy in the next 4. To confirm whether the radioactive node was really a sentinel lymph node the final patient in this series underwent laparoscopic retroperitoneal lymph node dissection with a unilateral template. RESULTS: Sentinel lymph nodes were detected in all patients by lymphoscintigraphy and handheld gamma probe, and each node varied. Right tumors in sentinel lymph node were detected at the inter-aortocaval, paracaval or common iliac region. Para-aortic lymph nodes were detected as sentinel lymph node in cases of left tumor. In the 4 patients who underwent gamma probe navigated laparoscopic procedure sentinel lymph nodes were easily detected and safely removed for pathological examination. In the last patient who underwent laparoscopic lymph node dissection micrometastasis was found only at the sentinel lymph node. CONCLUSIONS: Sentinel lymph node can be detected by lymphoscintigraphy and handheld gamma probe. Gamma probe guided laparoscopic biopsy of sentinel lymph node is technically possible. These techniques may have a role in the management of clinical stage I testicular tumor but further trials are required for establishment of the concept of sentinel lymph node in testicular tumor.