Therapy of hepatocellular carcinoma with iodine-131-lipiodol. Results in a large German cohort

AIM

To evaluate the efficacy and tolerance of iodine-131-lipiodol ((131)I-lipiodol) for hepatocellular carcinoma (HCC) in German long term patients and comparison with medically treated controls.

PATIENTS, METHODS

38 courses of intra-arterial (131)I-lipiodol therapy with a total activity up to 6.7 GBq were performed in 18 patients with HCC (6 with portal vein thrombosis). Liver and tumour volume and lipiodol deposition were measured by computed tomography and (131)I activity by scintigraphy. Therapeutic efficacy was determined by tumour volume change and matched-pairs analysis in comparison to medically (i.e. tamoxifen or medical support) treated patients.

RESULTS

Tumour volume decreased in 20/32 index nodules (63%) after the first course. Repeated therapy frequently resulted in further tumour reduction. Overall response to treatment was partial in 11 nodules, minor response in 4 nodules, and disease was stable in 12 and progressive in 5. Significant response was associated with pretherapeutic nodule volume up to 150 ml (diameter of 6.6 cm). Survival rate after 3, 6, 9, 12, 24 and 36 months was 78, 61, 50, 39, 17, and 6%. Matched-pairs analysis of survival revealed (131)I-lipiodol to be superior to medical treatment. The most important side effect was a pancreatitis-like syndrome whereas overall tolerance was good.

CONCLUSION

The long term results confirm that HCC therapy with (131)I-lipiodol is effective and probably superior to medical treatment. Tumour nodules of up to 6 cm diameter are well suited for this therapy even in the presence of portal vein thrombosis.

FDG uptake after intraarterial chemotherapy in head and neck cancer

AIM

The intraarterial chemotherapy (i.a.CHT) using high dose cisplatin combined with systemic neutralization in patients with head and neck cancer (HNSCC) is used to reduce the tumor volume preoperatively. Aim of the study is the evaluation of the influence of i.a.CHT on the metabolism of fluor-18-deoxyglucose (FDG) in the primary and lymph nodes (LN). The value of FDG positron emission tomography (PET) preoperative and as follow-up method after i.a.CHT is examined.

PATIENTS, METHODS

Altogether 16 patients with HNSCC underwent two preoperative FDG PET examinations: the baseline examination one week before and the follow-up three weeks after i.a.CHT. The SUVmax values of the primary and the LN and LN metastases were evaluated and compared with each other and the histopathology.

RESULTS

The SUVmax value of the primary decreased after i.a.CHT significantly from a median (25 (th) percentile/75 (th) percentile) of 6.4 (4.1/7.8) to 3.6 (2.4/6.7) (p = 0.01). In 11 out of 16 patients cervical LN metastases were detected. The cervical LN metastases showed a decrease of the SUVmax value from 3.6 (2.3/4.8) in the pretreatment examination to 2.3 (1.7/3.6) after i.a.CHT (p = 0.008). Only in one patient with LN metastases the SUVmax of the nodes increased. The histopathologically measured size of the LN metastases ranged from 2 to 30 mm. Non malignant LN did not reveal a significant SUVmax decrease after i.a.CHT (p = 0.13).

CONCLUSIONS

As expected, primaries of HNSCC showed a significant reduction of SUV after i.a.CHT. Compared to the primary the SUVmax decrease in LN metastases was less, but also significant. Since cytotoxic levels of cisplatin do not occur systemic, postinflammatory reactions of the LN or a lymphatic drainage of the chemotherapeutic drug into the LN could be an explanation. PET for staging of HNSCC must thus be performed prior to i.a.CHT.

Diagnostic value of FDG-PET and HMPAO-SPET in patients with mild dementia and mild cognitive impairment: metabolic index and perfusion index

OBJECTIVE

The diagnostic potential of F-18-2-fluoro-2-deoxy-D-glucose positron emission tomography (PET) and technetium-99m hexamethylpropylene amine oxime single-photon emission tomography (SPET) in early detection and differential diagnosis of early dementia was evaluated including a comparison of metabolic and perfusion indices (PI).

METHODS

Twenty-four patients with initial clinical suspicion of beginning dementia were examined, 12 of them with mild cognitive impairment. All patients underwent SPET and PET within 2 weeks. Data were compared with the final clinical diagnosis at follow-up - 9 with Alzheimer's disease (AD), 1 with frontotemporal dementia, 1 with vascular dementia (VD), 7 with mixed type of dementia (MIX) and 6 without any type of dementia. Metabolic indices (MI) and PI were compared with each other. The regional cerebral blood flow difference (rCBFdiff) calculated as local uptake difference between the right and left hemisphere was measured for patients with VD and MIX.

RESULTS

PET showed higher sensitivity and specificity in identifying the different types of early dementia (44--91 and 78--89%, respectively) than SPET (11--64 and 79--89%, respectively), especially in detecting AD (sensitivity 44%, specificity 83%) and MIX (sensitivity 71%, specificity 78%). Especially in patients with mild cognitive impairment, PET was the superior imaging modality for predicting dementia. Using PET, dementia could be excluded in all patients who did not develop dementia during the follow-up. In all patients, a weak correlation between PI and MI was observed (rho=0.64, p<0.002). The rCBFdiff in patients with VD and MIX ranged from 7 to 37%.

CONCLUSION

In this study on patients with initial suspicion of beginning dementia who underwent both imaging modalities, PET and SPET, PET was the superior imaging method, especially in the detection of early AD or MIX.

Diminished pregnancy rates in endometriosis due to impaired uterotubal transport assessed by hysterosalpingoscintigraphy

OBJECTIVE

To investigate uterotubal transport by means of hysterosalpingoscintigraphy (HSSG) in women with and without endometriosis.

DESIGN

A prospective observational study.

SETTING

University Hospital, Department of Obstetrics and Gynaecology, Division of Reproductive Medicine and Gynaecologic Endocrinology with 350 in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) cycles and 400 intrauterine insemination (IUI) cycles/year.

POPULATION

Cases included 56 infertile women with laparoscopic proven endometriosis and patent fallopian tubes. Twenty-two women with partners suffering from male factor infertility served as controls.

METHODS

A diagnostic cycle incorporating HSSG was performed. Subsequently, patients underwent either four cycles of timed intercourse (TI) or IUI in order to achieve pregnancy. If pregnancy did not occur, IVF or ICSI was performed.

MAIN OUTCOME MEASURES

Evaluation of uterotubal transport capacity in women with endometriosis and healthy controls.

RESULTS

Patients suffering from endometriosis (group I) showed a significant reduction in physiologic uterotubal transport function: While 20 patients (36%) had ipsi- or bilateral uterotubal transport, there was pathological uterotubal transport contralateral to the dominant follicle or a complete failure of transport capacity (negative HSSG) in 36 patients (64%). In the controls (group II), transport function was significantly different: 15 of 22 patients (68%) revealed ipsi- and bilateral tubal demonstration, while 5 patients (22%) showed contralateral transport and 2 patients (10%) showed negative HSSG (P= 0.01). Twenty-three pregnancies were observed (pregnancy rate: 29%). Eleven out of 14 (79%) women with ipsi- or bilateral tubal transport function fell pregnant by means of TI or IUI. In seven of nine patients (78%) with a failure in tubal transport, pregnancy was achieved by IVF/ICSI, despite acceptable semen parameters (P= 0.01).

CONCLUSIONS

Endometriosis is significantly associated with a reduction in physiologic uterotubal transport capacity compared with controls. This resulted in diminished pregnancy rates even in women with normozoospermic partners. Therefore, IVF/ICSI may be required even when fallopian tubes are patent or semen quality is normal.

The prognostic value of FDG PET in head and neck cancer. Correlation with histopathology

AIM

The aim of the present FDG PET study was to evaluate the prognostic value of the standardized uptake value (SUVmax) of head and neck cancer (HNSCC) with respect to the chemotherapy response and tumor recurrence.

METHODS

The FDG PET findings of 40 patients with HNSCC were compared with the final histopathology results after removal of the primary tumor and surgical neck dissection. The clinical T staging was based on clinical examinations and computed tomography was used for assessment of bone involvement. The pretreatment baseline SUVmax of the primary tumor were correlated with the intra-arterial chemotherapy response prior to the tumor resection and the frequency of tumor relapse.

RESULTS

The median SUVmax of tumors which did not relapse was 3.4, compared to a SUVmax of 4.7 for tumors with local tumor relapse (p=0.36, n.s.). Regarding chemotherapy response, the tumor SUVmax was significantly lower in cases with complete remission (CR) (median 2.6, n=11) compared to those with stable disease (5.8, n=10), (p=0.002). Whereas no tumor with CR after chemotherapy relapsed except stage IV tumors, tumor relapse was observed in both a stage II and a stage IV tumor without chemotherapy response.

CONCLUSIONS

In patients with HNSCC the tumor SUVmax seems to be a useful prognostic indicator for assessing the clinical chemotherapy response, but did not correlate significantly with the recurrence risk. Thus, in tumors with higher SUVmax alternative chemotherapy regimes have to be discussed.

The influence of CA 125 and CEA levels on the results of (18)F-deoxyglucose positron emission tomography in suspected recurrence of epithelial ovarian cancer

BACKGROUND AND PURPOSE

The follow-up of epithelial ovarian cancer (OCA) consists of clinical investigation, sonography, and tumor markers (TMs), especially CA 125. If tumor recurrence is suspected, other imaging modalities including positron emission tomography (PET) with (18)F-deoxyglucose (FDG) are often used. While there is still no consensus about the method of choice and the timing of its application, this study aims to find a TM threshold at which a PET would be appropriate.

MATERIAL AND METHODS

A total of 90 PET studies and the associated CA 125 values (normal value < 35 U/ml) were available in 71 patients during the follow-up after primary therapy for OCA. In 48 studies a CEA value (normal value < 3 ng/ml) was also available. The results of PET imaging were related to the level of TM increase.

RESULTS

In 23/90 studies the PET scan was normal. These patients had a median CA 125 of 13.3 U/ml (range 4.2-168 U/ml). In 67/90 studies the PET indicated a potential recurrence of OCA and the median CA 125 was 166.7 U/ml (range 13.3-4,060 U/ml). The TM levels were significantly different (p < 0.001, U-test). With one exception, there were no normal PET scans above CA 125 levels of 30 U/ml; between 20 and 30 U/ml PET was positive in 4/7 studies.

CONCLUSION

In suspected recurrence of OCA, if imaging modalities are to be used, an FDG PET may be considered. Since the costs of this investigation are high, it should be restricted to clinical situations where it is likely to be most effective. In this study a PET indication is worthwhile at CA 125 levels of approximately 30 U/ml.

[Positron emission tomography with (18)F-fluoro-2-deoxyglucose in cardiological diagnosis]

This clinically oriented review presents main principles of metabolism of cardiac muscle, pathophysiology of myocardial hibernation and stunning, as well as methodological principles of positron emission tomography (PET) of the heart with (18)F-fluoro-2-deoxyglucose ((18)F-FDG). Diagnostic and prognostic value of (18)F-FDG PET and scintigraphic sings of disturbed myocardial viability, contractility and metabolism are also described. Efficacy of (18)F-FDG PET is compared with other imaging methods such as radionuclide, ultrasound and radiological. Literature data and clinical cases demonstrate importance of preoperative diagnosis of hibernating myocardium in patients with ischemic heart disease. (18)F-FDG PET is a basic method of detection of potentially reversible pathological states of the heart (hibernation and stunning); it has high sensitivity and specificity as well as predictive power in relation to forthcoming course of ischemic heart disease. This noninvasive method of investigation provides unique information on severity of ischemic heart disease for stratification of patients in risk groups and selection of candidates for coronary artery bypass surgery or cardiac transplantation.

Residual kidney function after donor nephrectomy. Assessment by 99mTc-MAG3-clearance

AIM

We evaluated the long-term residual renal function after donor nephrectomy using 99mTc-mercaptoacetyltriglycin (MAG3)-clearance.

DONORS, METHODS

Altogether 49 kidney donors were examined using 99mTc-MAG3-clearance after nephrectomy for donation to a relative (m:f = 11:38; age 55+/-27 years). The donors were examined 16+/-8 years postoperatively (1.5-26 years). 42 donors (86%) showed normal creatinine values, whereas the other seven (14%) exhibited slightly elevated levels. 20 donors were examined pre- and postoperatively and compared intraindividually. The kidney function was compared to the age adapted normal values of healthy persons with two kidneys (67-133% of age related mean).

RESULTS

After nephrectomy all donors showed a normal perfusion, good secretion, merely physiological intrarenal transit and a normal elimination from the kidneys. The 99mTc-MAG3-clearance was 69+/-15% of the normal mean value of healthy carriers of two kidneys regardless of the gender. 20 donors with a preoperative examination showed a significantly reduced total renal function from 84+/-15% of the mean normal value preoperatively to 60+/-15% postoperatively (p <0.0005). 15 donors of this group exhibited a significant functional increase of the residual kidney from 40% initially to 60% after nephrectomy (p = 0.003). No correlation was found between the initial-99mTc-MAG3-clearance measured prior to nephrectomy and the clearance levels after nephrectomy. Also, no correlation between the preoperative 99mTc-MAG3-clearance and the postoperative serum creatinine values could be observed. Altogether, 22% of the donors (11/49) developed arterial hypertension 10+/-8 years after donation (1-23 years). This corresponds to the normal age prevalence of hypertension in the carriers of two kidneys. Three donors suffered from arterial hypertension prior to the operation.

CONCLUSION

Kidney donors with normal or slightly elevated creatinine values postoperatively show a 99mTc-MAG3-clearance value of 69% of the mean value of healthy carriers of two kidneys. This may serve as a reference value for healthy carriers of one kidney. In our study we demonstrated a good compensation of the contralateral kidney via renal scintigraphy by means of 99mTc-MAG3-clearance.

[Guideline for radioiodine therapy for benign thyroid diseases (version 3)]

The version 3 of the guideline for radioiodine therapy for benign thyroid diseases presents first of all a revision of the version 2. The chapter indication for radioiodine therapy, surgical treatment or antithyroid drugs bases on an interdisciplinary consensus. The manifold criteria for decision making consider the entity of thyroid disease (autonomy, Graves' disease, goitre, goitre recurrence), the thyroid volume, suspicion of malignancy, cystic nodules, risk of surgery and co-morbidity, history of subtotal thyroidectomy, persistent or recurrent thyrotoxicosis caused by Graves' disease including known risk factors for relapse, compression of the trachea caused by goitre, requirement of direct therapeutic effect as well as the patient's preference. Because often some of these criteria are relevant, the guideline offers the necessary flexibility for individual decisions. Further topics are patients' preparation, counseling, dosage concepts, procedural details, results, side effects and follow-up care. The prophylactic use of glucocorticoids during radioiodine therapy in patients without preexisting ophthalmopathy as well as dosage and duration of glucocorticoid medication in patients with preexisting ophthalmopathy need to be clarified in further studies. The pragmatic recommendations for the combined use of radioiodine and glucocorticoids remained unchanged in the 3rd version.

Limitations of dual time point FDG-PET imaging in the evaluation of focal abdominal lesions

AIM

For the evaluation of the diagnostic potential of dual time point FDG positron emission tomography (PET) in patients with suspicious focal abdominal uptake, dual time point PET imaging was compared with clinical findings.

PATIENTS, METHODS

In a prospective study, 56 patients exhibiting a solitary suspicious, intense abdominal FDG uptake, underwent dual time point PET imaging for staging or restaging of different malignant tumors, maximal standardized uptake value (SUVmax) measurements included. The first acquisition was started 64.8 +/- 19.5, the second 211.3 +/- 52.5 min after FDG injection. The final diagnosis based on CT or MRT imaging and a follow-up period of 12.6 +/- 2.8 months. Additionally, colonoscopy was done in 6 patients. In another 6 patients histopathology was obtained from CT guided biopsy.

RESULTS

Malignant focal abdominal lesions with a SUVmax <2.5 (n = 4) showed an uptake increase of > or =30%. In the remaining malignant cases with an uptake of > or =2.5 (n = 11), uptake increased in 64% and decreased in 36%. Malignant lesions showing FDG uptake decrease (n = 4) had an initial SUVmax value > or =2.5 and remained with a SUVmax > or =2.5 in the second imaging. In benign lesions with an initial SUVmax > or =2.5 (n = 31), the uptake increased in 17 patients (55%) and decreased in 14 patients (45%). All lesions which changed configuration (33%) were confirmed as benign (n = 5).

CONCLUSION

Using dual time point PET abdominal lesions show a very hetergenous uptake pattern regardless of their dignity. Malignancy can only be reliably excluded in lesions which change their configuration and in lesions with an initial SUVmax value <2.5 combined with an SUV decrease in the delayed imaging. Particularly abdominal lesions which show an initial SUVmax > or =2.5 combined with a SUV increase in the delayed imaging are suspicious for malignancy and need further clarification.

[Guideline for radioimmunotherapy of rituximab relapsed or refractory CD20(+) follicular B-cell non-Hodgkin's lymphoma]

This guideline is a prerequisite for the quality management in the treatment of non-Hodgkin-lymphomas using radioimmunotherapy. It is based on an interdisciplinary consensus and contains background information and definitions as well as specified indications and detailed contraindications of treatment. Essential topics are the requirements for institutions performing the therapy. For instance, presence of an expert for medical physics, intense cooperation with all colleagues committed to treatment of lymphomas, and a certificate of instruction in radiochemical labelling and quality control are required. Furthermore, it is specified which patient data have to be available prior to performance of therapy and how the treatment has to be carried out technically. Here, quality control and documentation of labelling are of greatest importance. After treatment, clinical quality control is mandatory (work-up of therapy data and follow-up of patients). Essential elements of follow-up are specified in detail. The complete treatment inclusive after-care has to be realised in close cooperation with those colleagues (haematology-oncology) who propose, in general, radioimmunotherapy under consideration of the development of the disease.

MRT der uterinen Adenomyose bei infertilen Patientinnen: Ergebnisse und klinische Rückschlüsse

PURPOSE

To evaluate the clinical value of magnetic resonance imaging (MRI) of the uterus and the pelvis in infertile female with symptomatic endometriosis for the assessment of uterine morphology and function.

MATERIALS AND METHODS

Forty-one infertile women (mean age: 33.2 years) with symptomatic endometriosis documented by laparoscopy were evaluated with high-field MRI (Sonata, Siemens) using T2- and T1-weighted sequences. In addition, the patients underwent hysterosalpingoscintigraphy (HSSG) for evaluation of the uterotubal transport capacity. Pathologic findings of the uterine junction zone were correlated with the laparoscopic results, clinical symptoms and uterotubal transport capacity.

RESULTS

Adenomyosis was diagnosed on T2-weigthed MR-images in 35 (85.4 %) patients (focal adenomatosis in 26 patients and diffuse adenomatosis in 9). Patients showing signs of adenomyosis tended to be older than patients without adenomyosis (mean age 34.1 years vs. 30.1 years) and showed a longer history of symptomatic endometriosis. A positive transport capacity in HSSG was observed in 73.1 % (19/26) of the patients with focal adenomyosis and in only 22.2 % (2/9) of patients with diffuse adenomyosis. In 83.3 % (5/6) of the patients without signs of adenomyosis, a positive uterotubal transport was documented.

CONCLUSION

MRI of the uterus is a helpful diagnostic tool for the diagnosis of adenomyosis and for planning further therapies. Patients with the diagnosis of adenomyosis showed a reduced uterotubal transport capacity that depended on the severity of adenomyotic changes and might be a possible cause of infertility.

Urinary fluorine-18 fluorodeoxyglucose excretion with and without intravenous application of furosemide

METHODS

Twenty patients suffering from malignancy received furosemide, twenty patients were examined by FDG-PET without diuretics. Urine volume and radioactivity were measured before and after acquisition. Bladder activity was evaluated qualitatively and quantitatively.

RESULTS

Radioactivity in the bladder was lower and the image quality higher in the furosemide group. SUV values showed a median of 3.0 in the furosemide and 6.0 in the control group. With furosemide, a larger excreted volume was seen compared to the control group. The furosemide group showed a significantly higher ratio of excreted/ injected radioactivity early after injection. However, the totally excreted radioactivity was not significantly different (p = 0.93).

CONCLUSION

Diuretics cause a higher urine volume with a diluted FDG concentration leading to an improved image quality. Furosemide accelerates early renal FDG elimination, reducing radiation exposure.

[Procedure guidelines for radioiodine therapy of differentiated thyroid cancer (version 2)]

The procedure guidelines for radioiodine therapy (RIT) of differentiated thyroid cancer (version 2) are the counter-part to the procedure guidelines for (131)I whole-body scintigraphy (version 2) and specify the interdisciplinary guidelines for thyroid cancer of the Deutsche Krebsgesellschaft and the Deutsche Gesellschaft für Chirurgie concerning the nuclear medicine part. Compared with version 1 facultative options for RIT can be chosen in special cases: ablative RIT for papillary microcarcinoma </=1 cm, ablative RIT for mixed forms of anaplastic and differentiated thyroid cancer, and RIT in patients with a measurable or increasing thyroglobulin concentration but without detectable metastases by imaging. The description of the pretherapeutic dosimetry now includes the isotopes (123)I and (124)I as well as a broader range of the activity of (131)I. Activities of 2-5 GBq (131)I are recommended for the first ablative RIT. If high accumulative activities of (131)I are expected, men who have not yet finished their family planning should be advised to the option of sperm cryoconservation. An interdisciplinary consensus is necessary whether the new TNM-classification (UICC, 6(th) edition, 2002) will lead to modified recommendations for surgical or nuclear medicine therapy, especially for the surgical completeness and for the ablative RIT of pT1 papillary cancer.

Case report: drug interference with MIBG uptake in a patient with metastatic paraganglioma

Metaiodobenzylguanidine (MIBG) labelled with iodine-131 ((131)I) has become a well established therapeutic tool for inoperable metastastic tumours of paraganglioma. There are different pharmacological substances known to interfere with MIBG-uptake which may result in a false negative MIBG scan. We present the case of a 26-year-old male polytoxicomanic patient with metastatic paraganglioma, who underwent MIBG therapy. During earlier therapies, MIBG uptake in the metastatic lesions was very high. A post-therapeutic whole-body scan subsequent to recent (131)I-MIBG therapy failed to detect the vast majority of metastatic lesions-except for two. (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) showed metastases with a similar distribution to the initial MIBG scan. The possible reasons for the discrepancy in the findings of the MIBG scans and the (18)F-FDG-PET scan are discussed with special emphasis on drug intake prior to MIBG administration, increased MIBG turn-over and unknown drug mixture interference with MIBG uptake.

Sentinel Node Biopsy in Head and Neck Cancer: Preliminary Results of a Multicenter Trial

BACKGROUND

The aim was to determine the reliability and reproducibility of sentinel node biopsy (SNB) as a staging tool in head and neck squamous cell carcinoma (HNSCC) for T1/2 clinically N0 patients by means of a standardized technique.

METHODS

Between June 1998 and June 2002, 227 SNB procedures have been performed in HNSCC cases at six centers. One hundred thirty-four T1/2 tumors of the oral cavity/oropharynx in clinically N0 patients were investigated with preoperative lymphoscintigraphy (LSG), intraoperative use of blue dye/gamma probe, and pathological evaluation with step serial sectioning and immunohistochemistry, with a follow-up of at least 12 months. In 79 cases SNB alone was used to stage the neck carcinoma, and in 55 cases SNB was used in combination with an elective neck dissection (END).

RESULTS

In 125/134 cases (93%) a sentinel node was identified. Of 59 positive nodes, 57 were identified with the intraoperative gamma probe and 44 with blue dye. Upstaging of disease occurred in 42/125 cases (34%): with hematoxylin-eosin in 32/125 (26%) and with additional pathological staging in 10/93 (11%). The sensitivity of the technique with a mean follow-up of 24 months was 42/45 (93%). The identification of SNB for floor of mouth (FOM) tumors was 37/43 (86%), compared with 88/91 (97%) for other tumors. The sensitivity for FOM tumors was 12/15 (80%), compared with 30/30 (100%) for other tumor groups.

CONCLUSION

SNB can be successfully applied to early T1/2 tumors of the oral cavity/oropharynx in a standardized fashion by centers worldwide. For the majority of these tumors the SNB technique can be used alone as a staging tool.

Therapy of hepatocellular cancer with iodine-131-Lipiodol

Most patients with hepatocellular carcinoma are not eligible for surgery at the time of primary diagnosis. Portal vein thrombosis is frequent and represents a contraindication for transarterial chemoembolisation. Transarterial therapy with iodine-131-Lipiodol is superior to systemic therapy in tumours up to diameters of 5 cm and may be performed even in cases with portal vein thrombosis. Compared to other intraarterial therapy procedures, iodine-131-Lipiodol shows the same efficacy but less side effects.

Positron emission tomography in patients with Hodgkin's disease: correlation to histopathologic subtypes

The aim of this study was to evaluate the initial staging and restaging of Hodgkin's disease (HD) according to histopathologic subtype (HST) using fluorine-18-deoxyglucose-positron emission tomography (PET). Special attention was paid to the accuracy of PET for detection of bone marrow infiltration (BMI). 44 patients with HD (m:f = 28:16, mean age 36 +/- 15 years) underwent PET; 16 were primary stagings and 28 restaging examinations. PET results were compared with methods of conventional staging including computed tomography (CT) and bone marrow biopsy. Viable tumor tissue was detected by PET in 25/44 cases, 16 nodular sclerosis (NS), 4 mixed cellularity (MC), 3 lymphocyte predominance (LP) and 2 cases with a nonclassified subtype (NC). FDG tumor uptake, measured as standard uptake value (SUV), ranged from 1.7 to 13. Maximum SUV in NS was 5.2 +/- 1.5 (2.5-7.3), 3.2 +/- 2.4 for MC, 2.6 +/- 0.7 for LP, and 9.1 +/- 3.8 for NC, respectively. In 7% of all patients (3/44) bone marrow infiltrations were detected by PET. PET is known for its superior detection of viable tissue in HD. In this study it was shown that HST does not influence the intensity of glucose metabolism, although 2 patients with NC showed the highest SUVs. In addition PET accurately detected focal BMI and may thus be applied before BMB to guide its optimal use.

Transplantation of progenitor cells after reperfused acute myocardial infarction: evaluation of perfusion and myocardial viability with FDG-PET and thallium SPECT

Clinical outcome after myocardial infarction depends on the extent of irreversibly damaged myocardium. Implantation of bone marrow-/circulating blood-derived progenitor cells has been shown to improve contractile cardiac function after myocardial infarction in both experimental and initial clinical studies. In the present study, first observations of the effect of local intracoronary progenitor cell infusion on the regeneration of infarcted cardiac tissue after acute myocardial infarction was evaluated by means of 18F-fluorodeoxyglucose positron emission tomography (PET) and 201Tl single-photon emission computed tomography (SPECT). Twenty-six patients underwent intracoronary infusion of bone marrow-derived (BMCs) (15 patients) or circulating blood-derived endothelial progenitor cells (EPCs) (11 patients) 4+/-2 days after acute myocardial infarction. Based on a left ventricular segmentation model (17 segments), mean signal intensities as a parameter of viability and perfusion in the infarct zone and non-infarct areas were calculated quantitatively by PET and SPECT at baseline and at 4 months of follow-up. Transplantation of progenitor cells was associated with a significant increase in the mean signal intensity (MSI) in the infarct zone from 54.5% (25th and 75th percentiles: 47.7%, 60.0%) to 58.0% (52.7%, 66.7%) on PET (P=0.013) and from 58.0% (49.5%, 63.0%) to 61.5% (52.5%, 70.2%) on SPECT (P=0.005). Global left ventricular ejection fraction (LVEF) increased from 53.5% (42.6%, 60.0%) to 58.0% (53.0%, 65.8%) (P<0.001). In the five patients without an increase in MSI on PET, LVEF changed from 60.0% (50.0%, 64.0%) to 72.0% (64.0%, 75.5%) at follow-up. PET and SPECT did not show any significant changes in MSI in the non-infarct areas [from 73% (68.5%, 76.2%) to 73% (69.7%, 78.0%) for PET and from 72.0% (66.5%, 77.6%) to 73.0% (67.5%, 78.2%) for SPECT]. There were no significant differences in myocardial viability and perfusion between BMC and EPC infusion. These preliminary results show that coronary stenting and transplantation of progenitor cells result in a significant increase in myocardial viability and perfusion. Therapeutic effects can be reliably measured by PET and SPECT.

[Positron emission tomography for preoperative lymph node diagnosis in esophageal carcinoma]

BACKGROUND

Exact preoperative staging is a prerequisite for the indication and the choice of appropriate operative technique for patients with esophageal carcinoma. The objective of this prospective study was to assess whether positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) increases the accuracy of preoperative lymph node staging with standard computed tomography (CT) and thus leads to a different surgical approach.

PATIENTS AND METHODS

Fifty-eight patients with carcinoma of the esophagus (46 men and 12 women) with a median age of 61 years underwent FDG-PET imaging of the neck, chest, and abdomen as well as CT of the chest and abdomen. Sensitivity, specificity, and accuracy were calculated for both imaging techniques to evaluate the detection of histologically verified lymph node metastases.

RESULTS

The FDG-PET showed higher specificity, whereas CT proved to be more accurate for detecting lymph node metastases not only of the abdomen (73% vs 59%) but also of the thorax (73% vs 63%). Resections were transhiatal in 23 patients and transthoracal in 16. As a supplement to conventional CT diagnostic procedure, FDG-PET was not decisive for the surgical approach.

CONCLUSIONS

Altogether, pretherapeutical PET imaging did not increase the accuracy of lymph node staging for our patients with esophageal carcinoma, which had already been defined through CT. Therefore, no new consequences resulted for the surgical procedure. Due to the high costs involved with PET investigation, lymph node staging with it is momentarily indicated mainly for clinical studies and when CT does not offer unequivocal results. Increased sensitivity of the already advantageous whole-body FDG-PET imaging by means of tumor-affinitive radiopharmaceuticals and optimized apparatus resolution could lead to new indications for this staging procedure.

The influence of thyroglobulin on functional imaging in differentiated thyroid cancer

AIM

Recombinant human thyroid stimulating hormone (rhTSH) for an exogenous stimulation of TSH and consequent thyroglobulin (hTG) synthesis has reinitiated a discussion about the usefulness of diagnostic procedures for the follow-up of differentiated thyroid cancer (DTC).

METHOD

Fifty consecutive patients with DTC who received whole-body iodine scintigraphy (WBS) and positron emission tomography (PET) were evaluated.

RESULTS

The work-up was normal in 18/50. In 32 patients, functional imaging detected DTC. In 44% exogenous TSH stimulation with rhTSH was used and thyroxin was withdrawn in the others. The hTG under stimulation ranged from 0.8 to 5.004 ng x ml(-1). It was below 2 ng x ml(-1) in four (12.5%) patients. In total, 91 tumour sites were identified by positron emission tomography (PET) and 47 sites by WBS. PET and WBS showed corresponding uptake in 38% of lymph node, 48% of parenchymal and 43% of bone metastases. PET detected additional 53% of lymph node (WBS 9%), 38% of parenchymal (WBS 14%) and 28.5% of bone metastases.

CONCLUSION

It is concluded that PET is more sensitive than WBS for the detection of DTC. The follow-up of DTC patients with hTG levels alone misses a significant number of true positive cases. Its use should therefore be restricted to selected low risk patients only.

Atypical thoracic and supraclavicular FDG-uptake in patients with Hodgkin's and non-Hodgkin's lymphoma

AIM

In FDG-PET imaging abnormal supraclavicular and paravertebral FDG uptake is a frequent finding which recently could be demonstrated to partly represent brown fat tissue. This study was carried out to further investigate causes for this phenomenon. Patients variables such as age, gender, body mass index (BMI) and the value of sedation and delayed imaging were compared with the presence of atypical uptake in 2 distinct groups of diseases, Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL).

METHODS

PET images of 81 patients (53 HD and 28 NHL) were evaluated for atypical uptake. In 5 patients additional delayed images were acquired. Sedatives were used in anxious patients (n=45).

RESULTS

Twelve out of 53 patients with HD and 2 out of 28 patients with NHL showed an atypical uptake. The BMI of patients with atypical uptake (median, 21 kg/m2 versus 24 kg/m2; p<0.05) and the age (median, 25 y versus 44 y; p<0.05) were significantly lower compared with patients without atypical uptake. In nearly 50% of all women with HD= or <30 y and 20% of all male patients with HD= or <30 y an atypical uptake was observed. Delayed images showed a SUVmax decrease in 4 patients and an increase in 1 patient. All patients with atypical uptake received sedatives which had an anxiolytic effect in all patients, but did not prevent atypical uptake.

CONCLUSION

Abnormal supraclavicular and paravertebral FDG accumulation occurs particularly in younger patients and those with lower BMI values. The use of sedatives or delayed acquisition does not increase the diagnostic information in these cases.