[F-18 fluorodeoxyglucose positron emission tomography in lung lesions]. / F-18-Fluorodeoxy-Glukose-Positronenemissionstomographie bei Lungenherden.

Positron emission tomography (PET) is used in an increasing number of patients for the evaluation of solitary pulmonary nodes as well as for staging and restaging of lung cancer. It adds metabolic information to the anatomical images of CT and may lead to significant cost savings as well in primary diagnostics as in restaging if patients are carefully selected.

Is sentinel lymph node biopsy reliable and indicated after preoperative chemotherapy in patients with breast carcinoma?

BACKGROUND: Many studies support the concept and accuracy of sentinel lymph node biopsy (SNB) for staging patients with breast carcinoma, which can be performed with low morbidity in lymph node negative patients. Preoperative chemotherapy (PC) plays an important role in the treatment of patients with operable breast carcinoma and is another approach with which to reduce radical surgery in patients with more advanced disease. It is of interest whether the sentinel lymph node accurately represents the axillary status after PC and, thus, whether the sentinel node concept can be applied to both groups. METHODS: Thirty-three patients underwent SNB after chemotherapy and prior to axillary lymph node dissection. RESULTS: The average greatest tumor dimension before chemotherapy (33 mm +/- 2 mm) was significantly larger (P = 0.000) than after therapy (20 mm +/- 3 mm). Histopathologic complete remission was seen in only three patients. One or two sentinel lymph nodes (average, 1.7 lymph nodes) were identified with certainty in 29 of 33 procedures and accurately predicted axillary lymph node status in all of these patients. Breast-conserving surgery was possible in 21 patients (64%), and axillary lymph nodes were involved in 22 patients (67%). CONCLUSIONS: Even after patients undergo PC, SNB seems to be a reliable method for accurate staging of the axilla in those more advanced breast carcinoma. Thus, axillary dissection may be avoided in certain patients. Lymph node involvement seems to be likely in women with suspicious axillary findings before chemotherapy who have no visible sentinel lymph nodes on preoperative lymphosintigraphy and in patients without recurrent tumors. Further investigation of the SNB concept in this patient group should be evaluated in larger studies.

Low frequency rTMS as an add-on antidepressive strategy: heterogeneous impact on 99mTc-HMPAO and 18 F-FDG uptake as measured simultaneously with the double isotope SPECT technique. Pilot study.

Single photon emission computed tomography (SPECT) and positron emission tomography (PET) are examination procedures that have shown that repetitive transcranial magnetic stimulation (rTMS) is biologically active. The aim of the present study was to investigate the patterns of regional cerebral 18F-fluorodeoxyglucose (18F-FDG) uptake and regional 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) uptake simultaneously during a series of therapeutic rTMS at low frequency. Four drug-resistant depressed patients underwent 10 rTMS as an add-on measure over 14 days. One day before and one day after TMS, simultaneous measurements of 18F-FDG, representing regional cerebral metabolic rate (rCMR), and 99mTc-HMPAO, representing regional cerebral blood flow (rCBF), were carried out. A conventional double head SPECT camera with 511 keV collimators was used. Statistically significant simultaneous overall changes of rCBF and rCMR were found in the upper prefrontal regions bilaterally in terms of increased uptake rates and in the left gyrus frontalis inferior in terms of decreased uptake rates of both isotopes compared to controls. Although this method improves our understanding of rTMS mechanism, there are limitations due to the lower resolution provided. Therapeutic rTMS seems to influence distinct, cortical regions affecting rCBF and rCMR.

Preliminary findings of simultaneous 18F-FDG and 99mTc-HMPAO SPECT in patients with depressive disorders at rest: differential correlates with ratings of anxiety.

The assumption of a dynamic coupling between regional cerebral blood flow (rCBF) and cerebral glucose metabolic rates (rCMRGlu) has been challenged by simultaneous measurements of both. Through the use of a dual-headed gamma camera with a 511-keV collimator applying the double isotope 18F-FDG and 99mTc-HMPAO SPECT technique, the uptake rates of these isotopes can be semi-quantitatively evaluated. Sixteen depressed patients, diagnosed by ICD-10 criteria and assessed with the 17-item Hamilton Rating Scale for Depression (HRSD), were studied. Based on the severity of HRSD-rated anxiety (item 10: low=1-21; high=3-4), two eight-patient subgroups were formed and compared with 12 age- and handedness-matched healthy control subjects. As regions of interest, we selected areas implicated in the neuroanatomy of anxiety and depression: hippocampus (hippo), basal ganglia (BG) and gyri temporales superiores (G.t.s.). In the control subjects, a significant statistical coupling between rCBF and rCMRGlu was revealed by the Spearman correlation coefficient only in left hippo and left BG. Patients in the low-anxiety subgroup demonstrated a marked dynamic coupling bilaterally for the G.t.s., while patients in the high-anxiety subgroup showed a significant statistical correlation of rCBF and rCMRGlu only in the left G.t.s. These findings indicate that a dynamic coupling between blood flow and glucose metabolism exists only in distinct brain regions, and that the depressive illness has an uncoupling effect on this correlation in the left BG. Furthermore, our results suggest that the HRSD anxiety score might interact with the underlying depressive illness to influence the relationship of rCBF and rCMRGlu.

[Sentinel node biopsy in breast cancer--a minimally invasive procedure for staging of the axilla]. / Die Sentinel Node Biopsy beim Mammakarzinom--ein minimal invasives Verfahren zum exakten Staging der Axilla.

Clinical examinations and imaging methods are not sufficiently reliable for an exact staging of axillary nodes in breast cancer. The sentinel node biopsy concept is a minimally invasive procedure to locate and remove the first and important nodes responsible for draining a tumor. Histologic examinations using immunohistochemical methods permit more accurate staging than hematoxylin and eosin staining alone. Between 4/1997 and 9/1998 a total of 62 patients with 65 breast cancers underwent surgery. The sentinel node procedure with radio tracers and/or blue dye was performed in patients with clinically negative or unclear positive findings in the axilla, with a primary tumor size less than 5 cm; 11 patients had received preoperative chemotherapy. The sentinel node biopsy was followed by axillary dissection in 44 cases. In 58 (89%) cases we found one or more (on an average 1.4) sentinel nodes with radio tracers (in 73%) and/or the blue dye method (in 85%). Axillary nodal status was correctly predicted in 43 of 44 (97.7%) cases; only in one patient was the sentinel node false negative. After preoperative chemotherapy sentinel nodes were found in 9 cases; all of these were predictive. Micrometastases were found in two patients only after cytokeratine staining. Our results concur with the experience of other study groups in regard of sentinel node biopsy. The sentinel node concept is a fascinating method; its importance in breast cancer treatment appears to be comparable with introduction of breast saving surgery in the 1980's.