Revista Espanola De Medicina Nuclear最新文献

Objective

To know the effective doses (E) that can be given in the common multimodal procedures in nuclear medicine, Single Photon Emission Tomography and Positron Emission Tomography, combined with Computed Tomography, SPECT/CT and PET/CT. Effective dose will be expressed according to Background Equivalent Radiation Time (BERT) and the contribution of the CT scan to the total dose will also be studied.

Material and methods

The effective dose of each procedure has been calculated as the sum of the external radiation dose (CT part) and internal one (radiopharmaceutical administration). Data from each side were collected through extensive literature search.

Results

A range of minimum and maximum effective dose [E_min, E_max] associated with each procedure is shown. These doses range from 0.5 to 49.1 mSv. BERT ranges from 2.6 months to 20.4 years. The CT contribution to the total effective dose varies from 2.1% to 93%, according to the image acquisition protocol and its purpose. Performing a diagnostic CT scan increases the dose up to a factor of 4.3 times compared to the dose used for CT acquisition for attenuation correction and anatomic localization.

Conclusions

This article focus on the effective dose level that can be given in multimodal procedures, bearing in mind that the data are subject to constant changes and should be updated periodically. It is important to know the dosimetric impact when the CT scan is added. The application of optimized protocols according to the indication of the study reduces the patient's exposure without the loss of significant information.

Malignant pleural mesothelioma is a relatively rare, but highly aggressive, tumor, associated to exposure to asbestos, with a life expectancy between 9 and 17 months. Chest pain and dyspnea are the most frequent symptoms. The most commonly used therapy is surgery accompanied by chemotherapy. Preoperative assessment, after chemotherapy, has been done using magnetic resonance imaging and computed tomography (CT). However, these techniques cannot predict early response to therapy, because of the slow structural change of the tumor. The aim of this case report is to review and learn about the growing use of PET-CT imaging with ¹⁸F-FDG in the preoperative staging of malignant pleural mesothelioma and its influence in selecting the most appropriate type of surgery.

Aim

To evaluate the usefulness of the ⁷⁵SeHCAT abdominal retention (AR) measurement in the early diagnosis of diarrhea syndrome (DS).

Methods

Thirty-seven patients with diarrhea syndrome within the first month of evolution were prospectively evaluated. The ⁷⁵Se-SeHCAT abdominal retention was measured 4 and 7 days post-administration of 0.01 mCi of ⁷⁵SeHCAT. The test was performed prior to treatment and at 3 months when the baseline study was positive. The test was considered positive if the RA was <25% at 4^th and <10% on the 7th day. The patients were visited at 3 months. Depending on the response, 3 groups were established: a) complete response: normalization of stool frequency, b) partial response, decrease of frequency or c) no response.

Results

Group A: The AR of ⁷⁵Se-SEHCAT was normal in 21 patients. Six were diagnosed of colonic diverticulosis, 8 of irritable bowel syndrome, 1 of lymphocytic colitis, 1 of post-gastroenteritis syndrome, 1 of celiac disease and 1 of stenosis of the cardia. Four are still under study. Group B: The AR of ⁷⁵Se-SEHCAT decreased in 16 patients. All showed abnormal AR at day 7 and all but 1 at day 4. Following administration of cholestyramine resin, 8 (50%) presented partial response and 8 (50%) complete response. At 3 months, AR had increased at day 4 and 9 at day 7.

Conclusion

The measurement of ⁷⁵SEHCAT abdominal retention allows the early diagnosis of bile acid malabsorption in 43% of the patients with DS. Measurement at 7 days seems more accurate than that at 4 days.

Aim

The aim of this study was to establish the efficacy and safety of sentinel lymph node biopsy for lymph node staging in patients with breast cancer and prior breast surgery, considering its extension, localization and time since the previous surgical procedure.

Material and methods

A sentinel lymph node biopsy was performed in 38 patients with early breast cancer and previous breast surgery: recent excisional biopsy in 22 patients (Group I), previous lumpectomy or mammoplasty in 16, including one case of cancer treated with breast-conserving surgery (tumor recurrence). Lymphoscintigraphy was performed after periareolar injection, also sometimes adding an injection near to the surgical scar. After removing the sentinel node, axillary lymph node dissection was performed when the lymph node was positive (and not localized).

Results

The efficacy of the scintigraphic localization of the sentinel node was 92.1% of the patients, with 15.8% of extra-axillary drainages. Axillary intraoperative detection was 81.6%. The identification rate after recent excisional biopsy or previous surgery was similar (81.8 vs 81.2%). However, extra-axillary sentinel nodes were more frequent in Group II (9.1 vs 25%). Having a localization of previous surgical procedures in upper outer quadrant caused drainages outside of the axilla more frequently (27.2 vs 11.1%). Axillary detection rate was similar to other quadrants (81.8 vs 81.5%). The rate of breast cancer-related events was 5.2% (2/38), without axillary recurrences (mean follow-up: 3 years).

Conclusion

Sentinel lymph node biopsy in patients with previous but not extensive breast surgery is safe. Extra-axillary drainages are more common when the previous surgical area was wide, especially in the upper-outer quadrant.