Biomedical subjects

L Kostakoğlu

Publications and source records attributed to L Kostakoğlu.

6 recordsLinked to original sources

PubMed2000

Impact of radiotherapy on normal brain tissue: semi-automated quantification of decrease in perfusion.

PURPOSE: We attempted to ascertain the impact of Co-60 conventional external radiotherapy (cRT) on the perfusion of normal brain tissue in relation to the radiation doses delivered to the tumors in patients with primary brain tumors. MATERIALS AND METHODS: After surgery 18 patients (pts) were due to undergo cRT with a total dose of 5400- 6400 cGy. All the patients had a Tc-99m-HMPAO SPECT study prior to cRT (basal), 15th and 30th days of cRT as well as 1 (in 6 pts), 3 (in 9 pts), and 6 (in 3 pts) months after cRT. For quantitative evaluation, the entire set of transverse slices were divided into 4 regions as frontal, parietal, occipital and temporal regions by means of a computer software program. Semi-automated quantification was performed on a total of 1392 regions in 87 studies to determine left to right ratios. An interregional difference of at least 10% was considered abnormal. RESULTS: After elimination of tumor sites, 80 normal brain regions showed decreased perfusion after cRT. The percent decrease in perfusion was (mean 22.5+/-9.9) significantly higher in areas irradiated with doses > 3000 cGy (p < 0.05). CONCLUSION: cRT has adverse effects on the perfusion of normal brain tissue for doses > 500 cGy. Our findings justify treating patients with small and limited lesions with stereotactic radiotherapy in order to minimize the adverse effects of cRT on normal tissues.

Adolescent↗

PubMed2000

Radiopharmaceuticals for the visualization of infectious and inflammatory lesions.

Many radiopharmaceuticals have been introduced for the scintigraphic demonstration of infectious and inflammatory lesions and some of them are currently in clinical use. They can be classified into two major categories according to their specificity. Specific radiopharmaceuticals include in vitro labeled leukocytes, radio-labelled monoclonal antibodies, and receptor specific small proteins and peptides. Nonspecific radiopharmaceuticals include radiolabelled nanocolloids, liposomes, macromolecules such as human immunoglobulin, dextran and human serum albumin, various small molecules and ions. In this review article radiopharmaceuticals in their respective groups are discussed as to the efficacy, and other parameters such as the physical characteristics of the radionuclides used, radiochemistry involved, availability, cost and biodistribution, emphasizing recent developments.

Animals↗

PubMed1997

Visualization of uveal amelanotic melanoma with technetium-99m(V) dimercaptosuccinic acid.

The possibility of using technetium-99m(V) dimercaptosuccinic acid, Tc-99m DMSA, in the evaluation of uveal amelanotic melanoma was assessed in this study. Both planar and SPECT images clearly demonstrated the tumor. Following confirmation of our results by contemporaneous ultrasonography and MRI the patient was treated with Iodine-125 brachytherapy. In combination with other diagnostic tests, Tc-99m(V) DMSA scintigraphy may play a role in the detection of uveal melanoma and its possible systemic metastases.

Adult↗

PubMed1996

Technetium-99m-ethylenedicysteine in the diagnosis and follow-up of renovascular hypertension.

Technetium-99m-ethylenedicysteine (99mTc-EC) captopril scintigraphy performed in a patient with severe hypertension revealed increased parenchymal retention in the left kidney, suggesting renal artery stenosis. After angiographic confirmation of renal artery stenosis, percutaneous transluminal angioplasty (PTA) was performed on the left renal artery. Captopril scintigraphy after PTA showed normal findings with no evidence of parenchymal retention, consistent with reversal to normal kidney functions. In light of this case of renal artery stenosis, it was concluded that 99mTc-EC can be used successfully as a potential renal agent in the diagnosis and follow-up of renovascular hypertension.

Adult↗

PubMed1996

Comparison of 201Tl, 99Tcm-MIBI and 131I imaging in the follow-up of patients with well-differentiated thyroid carcinoma.

Problems stemming from the withdrawal of TSH suppressing doses of T4 or T3 and false-negative studies associated with 131I scintigraphy have justified the search for other radionuclides in the follow-up of patients with well-differentiated thyroid carcinoma. Although 201Tl and 99Tcm-MIBI (MIBI) have been suggested as alternatives, their role in the detection of residual and recurrent disease has yet to be established. We therefore studied 36 patients who had undergone total or near total thyroidectomy for well-differentiated thyroid carcinoma to determine the imaging potential of 201Tl, MIBI and 131I in the detection of residual or recurrent disease. Eighteen of the 36 patients had undergone 131I ablation. Imaging was performed 20 min following the intravenous injection of 111 MBq 201Tl or 555 MBq MIBI, or 48 h after the oral ingestion of 185 MBq 131I. The overall concordance between the 201Tl, MIBI and 131I scans was 70%. The concordance between thyroglobulin (TG) levels and the 131I scans was 78%; that between the 201Tl and MIBI scans and TG levels was 83%. Among the group of pre-ablative patients, there were six false-negative results with 201Tl and three false-negative results with MIBI. Among the post-ablation group, the 201Tl and MIBI scans were falsely negative in five patients. The 131I scans revealed all known residual or recurrent diseases. In conclusion, 201Tl, MIBI or TG levels should not be used in the place of 131I for the detection of residual or recurrent thyroid cancer. However, in patients who have not had their TSH suppressing doses of T4 or T3 withdrawn, the role of 201Tl and MIBI is debatable.

Adenocarcinoma, Follicular↗

PubMedDate not supplied

Can bone scintigraphy detect additional metastatic sites unrevealed by CT in patients with recurrent ovarian carcinoma?

A patient who presented with recurrent ovarian carcinoma with elevated levels of CA 125 was evaluated for skeletal metastases by routine whole body bone scintigraphy. Although no bone metastasis was visualized, there was intense accumulation of tracer in the soft tissues corresponding to the liver, pelvis, and intestinal/peritoneal surface, suggestive of metastatic disease. Although liver and pelvic soft tissue metastases were confirmed by CT and USG, intestinal/peritoneal metastases could not be disclosed by either modality.

Abdominal Neoplasms↗