[Sentinel lymph node diagnosis in prostatic carcinoma: II. Biokinetics and dosimetry of 99mTc-Nanocolloid after intraprostatic injection]. / Sentinel-Lymphknoten-Diagnostik beim Prostatakarzinom: Teil II: Biokinetik und Dosimetrie von 99mTc-Nanokolloid nach intraprostatischer Injektion.

AIM: To visualise the sentinel lymph nodes (SLNs) of the prostate we injected the radiotracer into the parenchyma of the prostate. The activity was deposited in liver, spleen, bone marrow, urinary bladder and regional lymphatic system. The aim of this work is to determine biokinetical data and to estimate radiation doses to the patient. METHODS: The patients with prostate cancer received a sonographically controlled, transrectal administration of 99mTc-Nanocoll, injected directly into both prostate lobes. In 10 randomly selected patients radionuclide distribution and its time course was determined via regions of interest (ROIs) over prostate, urinary bladder, liver, spleen and the lymph nodes. The uptake in the SLNs was estimated from gamma probe measurements at the surgically removed nodes. To compare tumour positive with tumour free lymph nodes according to SLN-uptake and SLN-localisation we evaluated 108 lymph nodes out of 24 patients with tumour positive SLN. For calculating the effective dose according to ICRP 60 of the patients we used the MIRD-method and the Mirdose 3.1 software. RESULTS: The average uptake of separate organs was: bladder content 24%, liver 25.5%, spleen 2%, sum of SLN 0.5%. An average of 9% of the applied activity remained in the prostate. The residual activity was mainly accumulated in bone marrow and blood. Occasionally a weak activity enrichment in intestinal tract and kidneys could be recognized. The effective dose to the patient was estimated to 7.6 microSv/MBq. The radioactivity uptake of the SLN varied in several orders of magnitude between 0.006% and 0.6%. The probability of SLN-metastasis was found to be independent from tracer uptake in the lymph node. The radioactivity uptake of the SLNs in distinct lymph node regions showed no significant differences. CONCLUSION: The radiotracer is transferred out of the prostate via blood flow, by direct transfer via the urethra into the bladder and by lymphatic transport. Injecting a total activity of 200 MBq leads to a mean effective dose of 1.5 mSv. It is not recommended to use the tracer uptake in lymph nodes as the only criterion to characterize SLNs.

[Sentinel lymph node diagnosis in prostatic carcinoma: I: Method and clinical evaluation]. / [Sentinel lymph node diagnosis in prostatic caricnoma: I: Technique and clinical evaluation]

AIM: Evaluation of the significance of lymphoscintigraphy and intraoperative probe measurement for the identification of the sentinel lymph node (SLN) in prostate cancer. PATIENTS AND METHOD: In 117 patients with prostate cancer scintigrams in various projections were acquired till approximately 6 hours p.i. after ultrasound guided transrectal intraprostatic injection of 99mTc-Nanocoll. On the following day the SLNs were identified in the operation theatre with a gamma probe and removed. Pelvic standard lymph node dissection followed SLNE. RESULTS: In three of 117 patients with preoperative lymphoscintigraphy no SLN was scintigraphically detectable. These three patients had antecedent transurethral resection of the prostate. In 113 of the residual 114 patients SLN could be intraoperatively localized. In the mean four SLNs per patient were removed. 28 of 117 patients had pelvic lymph node metastases. In 25 cases SLN were right-positive, in one false-negative and in one intraoperatively not detectable. In one patient we found macrometastasis of up to 4 cm diameter (one SLN was tumour positive). In 15 cases only the SLN was bearing tumour. CONCLUSION: The SLNE with preoperative lymphoscintigraphy and intraoperative gamma probe measurement is suitable for detecting lymph node metastasis in prostate cancer. SLNE is superior to the surgical techniques commonly used in pelvic lymphadenectomy.

[Radio-guided parathyroidectomy: successful intraoperative parathyroid localization diagnosis with 99mTc-sestamibi in primary and recurrent hyperparathyroidism]. / Radio-guided Parathyreoidektomie: Erfolgreiche intraoperative Lokalisationsdiagnostik bei primärem und rezidivierendem Hyperparathyreoidismus mit 99mTc-MIBI.

INTRODUCTION: In addition to ultrasonography, CT scan, MRI and venous sampling, 99mTc-MIBI scintigraphy has gained increasing acceptance in preoperative localization of abnormal parathyroid tissue. The sensitivity of this radionuclide method is 87% in primary (p), 58% in secondary (s), and 75% in recurrent hyperparathyroidism (HPT). This study evaluated the use of intraoperative nuclear mapping in patients with HPT. METHODS: Retrospective analysis was performed in 24 patients with HPT (18 p, 4 s, 2 recurrent) undergoing a technetium-sestamibi-guided neck exploration during an 18-months period. Abnormal parathyroid tissue was localized using an intraoperative gamma probe detector 2 h after application of 700 MBq 99mTc-sestamibi and verified by pathology. RESULTS: Intraoperative nuclear mapping identified 15 of 18 adenomas in patients with pHPT. The target-to-background ratio was 1.3 to 4.1 in these patients compared to 1.0 to 1.2 in undetected adenomas. In 67% of these patients we performed a minimally invasive open parathyroidectomy. In two cases of recurrent HPT the scan-guided detection of ectopic parathyroid tissue was efficient. In contrast, the method was less helpful in four patients with multiglandular disease. CONCLUSION: The intraoperative use of a gamma probe detector is highly effective in identifying parathyroid adenomas in pHPT and recurrent HPT and supports minimally invasive techniques.

Utility of the dexamethasone suppression test in the diagnosis of poststroke depression.

The utility of the dexamethasone suppression test (DST) in the diagnosis of depression was examined in an outpatient sample of 29 stroke patients. Results indicated that the DST's sensitivity was 15%, its specificity was 67%, and its positive predictive value was 48%. These findings suggest that the DST yields no more information than would be gained from random assignment of the diagnosis of depression. Therefore, it is not a useful measure of mood in these patients.