A new species of Cyrtodactylus (Squamata: Gekkonidae) from central New Guinea

We describe a new species of bent-toed gecko in the genus Cyrtodactylus from hill forest in Southern Highlands Province, Papua New Guinea. Cyrtodactylus manos sp. nov. can be distinguished from all congeners in New Guinea by its small size in combination with aspects of colouration and body and tail scalation. The new species adds to the growing number of vertebrate species known only from karstic mountains along the southern edge of New Guinea's Central Cordillera, suggesting that this region holds previously overlooked endemic karst-associated biota.

The purportedly Indo-Australian gecko species Cnemaspis timoriensis (Duméril amp; Bibron, 1836) is actually the first named species of the neotropical genus Gonatodes Fitzinger, 1843 (Squamata: Gekkonidae)

Only a single known specimen of Cnemaspis timoriensis (Duméril Bibron, 1836) exists, the holotype in the Muséum National d'Histoire Naturelle in Paris, France. Purportedly collected by Charles Gaudichaud-Beaupré in the year 1818 on Timor Island in the Lesser Sunda Archipelago during the circumnavigation of the globe by the vessel L'Uranie, intensive research on Timor has failed to produce additional specimens or any similarly appointed gecko. Using a series of detailed morphological comparisons, we provide irrefutable evidence that the animal in question is not a member of Cnemaspis but of the neotropical genus Gonatodes. Furthermore, we ascertained that C. timoriensis is conspecific with G. humeralis, a widely distributed South American species. We also show that a specimen labeled with the timoriensis name in the Museum für Naturkunde, Berlin, Germany is not conspecific and not part of a type series. While the taxon name timoriensis has nomenclatural priority over the two-decades-younger name humeralis, usage would dictate that to preserve the nomenclatural stability of neotropical geckos the junior synonym should be retained. An application to the International Commission on Zoological Nomenclature to this effect is in preparation.

The Knight and the King: two new species of giant bent-toed gecko (Cyrtodactylus, Gekkonidae, Squamata) from northern New Guinea, with comments on endemism in the North Papuan Mountains

The diverse biota of New Guinea includes many nominally widespread species that actually comprise multiple deeply divergent lineages with more localised histories of evolution. Here we investigate the systematics of the very large geckos of the Cyrtodactylus novaeguineae complex using molecular and morphological data. These data reveal two widespread and divergent lineages that can be distinguished from each other, and from type material of Cyrtodactylus novaeguineae, by aspects of size, build, coloration and male scalation. On the basis of these differences we describe two new species. Both have wide distributions that overlap extensively in the foothill forests of the North Papuan Mountains, however one is seemingly restricted to hill and lower montane forests on the ranges themselves, while the other is more widespread throughout the surrounding lowlands. The taxon endemic to the North Papuan Mountains is related to an apparently lowland form currently known only from Waigeo and Batanta Island far to the west - hinting at a history on island arcs that accreted to form the North Papuan Mountains.

A new species of the diurnal gekkonid genus Pristurus Rüppell, 1835 from the Red Sea island Hanish al-Kabir, Yemen

Abstract

We describe a new species of gecko of the genus Pristurus from the Yemenite Red Sea Island Hanish al-Kabir. It is a small species (snout-vent length less than 30 mm) of the genus, distinguished from its congeners by a unique combination of morphological characters. Superficially, it is most similar to P. rupestris, but differs mainly by a longer and narrower snout, by its strongly compressed tail, presence of a lateral caudal groove, by a tail crest present in both sexes, by a higher number of scales bordering infralabials and a higher midbody scale count. The new species is tentatively considered to represent an island endemic. Its possible origin is briefly discussed.

Primary cervical malignant teratoma with a rib metastasis in an adult: five-year survival after surgery and chemotherapy. A case report with a review of the literature

We report a case of a man presenting with a cervical malignant teratoma and a chondrosarcomatous rib metastasis. He was alive and free of recurrence five years and 10 months (= 70 months) after resection of the primary mass, followed by chemotherapy and subsequent resection of the rib tumor. This is the 35th patient reported in the literature and the first description in which an 'adjuvant' or primary chemotherapy was used. Previous patients with a cervical malignant teratoma, reported after lethal outcome, had survivals of one to 22 months (median nine months). In all patients with a preoperative clinical impression of an aggressive, differentiated or undifferentiated malignancy, the definite diagnosis of teratoma could only be made histologically. By analogy to germ cell tumors, the prognosis of malignant teratoma might be improved if complete excision is combined with new, adjuvant chemotherapy protocols for germ cell tumors. Lessons learned from this case are placed in the context of germ cell tumors in general and of non-gonadal malignant teratomas in particular.

[Choice of therapy in unifocal functional autonomy of the thyroid gland with hyperthyroidism]

Over the last 20 years, unifocal functionally autonomous nodes (UFA) of the thyroid have accounted for more than one third of all patients with hyperthyroidism in the former iodine-deficient and goiter-endemic region of Bern. This situation calls for a special diagnostic approach, i.e. etiologic diagnosis of any solitary nodule and careful consideration of therapy in contrast to regions with iodine excess where UFA is very rare, such as the USA. Therapy is recommended even where hyperthyroidism is still latent (blocked TRH test, normal TT3 and TT4) and reliably leads to subjective and objective improvement even in oligosymptomatic individuals. The safe and easy radioiodine therapy (RIT) is preferred in elderly patients with associated conditions. Surgical resection is recommended chiefly where malignancy is suspected or RIT is technically inappropriate. Both methods produce prompt eradication of the source of hyperthyroidism. The most frequent complication is hypothyroidism requiring lifelong follow-up.

[Scintigraphic method in the quantification of morphological and functional changes of thyroid autonomy before and after iodine radiotherapy]

The regional excess of function and cell mass in potentially "toxic" thyroid areas with nonimmunogenic hyperthyroidism (NIH) (unifocal [UFA, previously "toxic adenoma"] and multifocal functional autonomies [MFA or "toxic goiter"]) are quantified by an enhanced diagnostic method: double isotope subtraction scintigraphy (Ssc) with radioiodine and 99mTc-MIBI. In 125 patients, a toxicity index T was derived from the Ssc (*J-*MIBI), and a cell density index Q from the *MIBI image. The median value of T, as an expression of the regional autonomous excess function (165 in UFA, 15 in MFA), by far exceeded the median value of Q (3.8 in UFA, 2.0 in MFA). The significant (p < 0.001) effects of radioiodine therapy (RIT) were monitored by the changes towards normalization of T and Q in 53 patients in follow-ups 3 and 9 months thereafter. Our aim was (a) to extend the conventional field of measurement of NIH-hyperthyroidism with the scintigraphically quantified function and morphology, and (b) to compare the return to euthyroid state with scintigraphic scarification of the functionally autonomous areas.

[Why is iodine deficiency once again present in the Berne region?]

Owing to the progressive iodination of salt in Switzerland (5, 10, 20 mg KI/kg in the years 1922, 1965, 1980), iodine deficiency in former endemic goiter regions had nearly disappeared. In several areas of the country, urinary iodine had increased from below 30 micrograms/24 h (1920) to > 100 micrograms/g creatinine (1981-1990). In 1991-1992, however, the 24-h-iodinuria in a subgroup of 160 examinations out of a total of 289 persons in Berne was again insufficient (norm > 150 micrograms J/24 h): mean 121 micrograms/24 h (82 micrograms/l), median 107.8 micrograms/24 h (67 micrograms/l). Follow-up of one proband in 1991-1992 (n = 9) and 1996 (n = 11) yielded average 24-h-iodinurias in the slightly deficient domain of (mean +/- SD) 104 +/- 57 micrograms/ 24 h (75 +/- 30 micrograms/l) and 103 +/- 27 micrograms/24 h (44 +/- 17 micrograms/l) respectively, with a wide range (45-258 micrograms l/24 h globally). Possible reasons for the decreasing iodide intake in recent years, resulting in the 1990s in a marginally deficient supply, are reduced intake of salt in recent decades, increased consumption of foodstuffs prepared with non-iodized salt, dietary diversification, and frequent meals away from the family table. Therefore, intake of non-iodized salt should be avoided in Switzerland.

Noninvasive differentiation of meningiomas from other brain tumours using combined 111Indium-octreotide/99mtechnetium-DTPA brain scintigraphy

We have studied prospectively 47 patients with CNS tumours including 16 meningiomas and 33 other tumours using combined 111In-octreotide and 99mTc-DTPA brain scintigraphy. 111In-octreotide scintigraphy was used to image somatostatin receptors (SSR) and 99mTc-DTPA scintigraphy was used to assess the integrity of the blood-brain barrier (BBB). A total of 32 tumours (65%) were detected. All SSR positive tumours also had positive 99mTc-DTPA scans and all SSR negative tumours were negative on 99mTc-DTPA scans. Among the tumours located outside the BBB, all meningiomas and two out of six schwannomas were positive on combined SSR/99mTc-DTPA scintigraphy. Among the tumours located inside the BBB, seven out of nine gliomas grade I-III were negative, whereas all glioblastomas were positive. Other positive tumours included one malignant non-Hodgkin lymphoma and two cerebral metastases. SSR scintigraphy alone was non-specific in the diagnosis of meningiomas, as 16 non-meningiomatous tumours also had positive SSR scans probably due to a breakdown of the BBB (excluding the malignant lymphoma). Measuring the tumour-to-background ratio on SSR scans improved specificity, but sensitivity was decreased below 70% because some meningiomas were only slightly positive. Only the ratio of SSR scintigraphy to conventional 99mTc-DTPA brain scintigraphy (SSR-to-BS index) allowed a reliable differentiation of meningiomas from other CNS tumours, most notable from schwannomas (sensitivity: 94%; specificity: 100%). Our results support the usefulness of combined SSR and conventional brain scintigraphy in the noninvasive pre-operative diagnosis of meningiomas.

Diagnostic angioscintigraphic evaluation of malignant hepatic tumors before catheter embolization: determination of shunt, flow distribution, and reflux

PURPOSE

The aim of this study was to evaluate quantitatively arteriovenous shunts in malignant liver tumors by injection of 99mTc macroaggregates of albumin (MAA) into the tumor-feeding artery after selective catheterization.

METHODS

In 40 patients with malignant liver tumors (33 hepatocellular carcinomas and 7 metastases of colorectal cancer), a mean dose of 200 MBq 99mTC MAA was injected arterially during angiography. The embolized area and the lungs were then visualized using a gamma camera. A dedicated computer program calculated pulmonary shunt rates.

RESULTS

The majority of patients (n = 30) with hepatocellular carcinoma showed small shunts varying from 0 to 15%; only 3 of these patients had shunts ranging from 18% to 37%. In patients with colorectal carcinoma metastases (n = 7) the shunt varied from 0 to 3% (2 +/- 1%), probably due to a physiological shunt in normal liver tissue in the embolized area. Importantly, the degree of shunt found bore no correlation to the tumor volume or to the pattern of vascularity on angiography.

CONCLUSION

Diagnostic angioscintigraphy is a useful tool for pretherapeutic evaluation of the capacity of an individual tumor to retain particles and to measure extratumoral shunting; these are essential for therapy planning, as they can help to increase the safety and effectiveness of embolization.

Separation of autonomous function from cell density in non-immunogenic hyperthyroidism--II. quantified comparison before and after radioiodine therapy

Regional autonomous cell mass (Q: cell density ratio) and function (T: toxicity index) were compared by double isotope parametric thyroid scintigraphy (Als et al., Nucl. Med. 1995; 34) in 53 patients with non-immunogenic hyperthyroidism before and after radioiodine therapy (aRIT) and showed a break-down (medians) of Q: 4.3-->1.0 (toxic adenomas: TA), 2-->1.1 (multifocal functional autonomies: MFA)(p < 0.0001) as of T: 96-->1.7 (TA), 15-->1.1 (MFA) (p < 0.001). Five functional aRIT patterns resulted: euthyroidism (n = 37, 70%), at half with scarred/non-scarred autonomous areas (low/higher T, respectively), primary hypothyroidism (n = 4), residual hyperthyroidism (n = 7), secondary hyperthyroidism (n = 5). The last two groups with persistent subnormal TSH values were clearly separated by divergent T, thyroxine and triiodothyronine levels. A resulting T > 1 may represent a clinically sub-critical mass of residual autonomous tissue. This new technique facilitates individual pretherapeutic evaluations and aRIT quality control.

Renal pathology after arterial yttrium-90 microsphere administration in pigs. A model for superselective radioembolization therapy

RATIONALE AND OBJECTIVES

To test the selectivity of tissue damage in radioembolization, the authors performed an experimental study using superselective administration of yttrium-90 particles to deliver up to 100 Gy to the porcine kidney. Patterns and severity of damage in test organs were compared with controls, and the feasibility of this model is discussed.

METHODS

Eight sows were included in the study. Bio-Rex 70 particles were applied via selective catheterization of the renal artery. Four pigs received inactive particles and four pigs received active particles. Organ distribution and shunting of yttrium-90 were determined, and kidney damage patterns were histologically analyzed.

RESULTS AND CONCLUSIONS

The model demonstrates that yttrium-90-labeled resin particles can superselectively be applied. Retention of beta activity in the target organ was more than 95%. In addition to tissue shrinkage from mechanical obstruction, considerable damage ensued mainly by radiation-induced arterial necrosis and arteritis.

Separation of autonomous function from cell density in non-immunogenic hyperthyroidism. I. Quantification by double-isotope parametric scintigraphy

A new quantitative subtraction method of thyroid scans is proposed which shows that regional function (F) by far exceeds regional cellularity or cell density (C) in potentially toxic thyroidal areas of non-immunogenic hyperthyroidism (NIH).

METHODS

A multistep processing of radioiodine and MIBI thyroid scans of patients with non-immunogenic hyperthyroidism led to normalized images of regional function excess and of perinodular enhancement. Two numeric factors were derived from regions of interest: Q (cell density ratio) comparing MIBI uptake in autonomous and suppressed areas and T (toxicity index): the maximal F/C contrast.

RESULTS

Q never exceeded 61; T, however, expanded toxicity levels over a range of 6-8735 with toxic adenomas (median = 165) and with hot areas of multifocal functional autonomy (median = 15). T was weakly correlated to serum TT3 (r = 0.41), but not to autonomous tissue mass, ultrasonographic or cytologic criteria.

CONCLUSIONS

T is governed by inherent features of autonomous tissue and the response of the imbedded thyroid tissue to TSH stimulation. This standardized technique consolidates experiences from visual analysis; the huge T range mirrors the natural evolution from compensated autonomy towards hyperthyroid, decompensated stages.

[Toxic adenomas of the thyroid gland becoming less frequent in Berne]

The frequency distribution of immunogenic and non-immunogenic hyperthyroidism (IH, NIH) was evaluated retrospectively in the former endemic goiter area of Berne over a 15-year period (1976, 1982, and 1991). Out of 12,320 patients referred for thyroid examinations, 9.1% were hyperthyroid. NIH still predominates with a constant frequency of 59%; but the ratio between toxic adenomas (TA) and multifocal functional autonomies (MFA) was significantly inversed, from 2.6 over 0.9 to 0.4. The frequency of TA decreased from 41% to 17% and that of MFA increased from 16% to 38%. The arithmetic mean age at diagnosis was constant: 53.9 (IH), 61.5 (TA) and 67.5 years (MFA). The decreasing frequency of TA over the last 15 years is explained by an increased but still insufficient iodine supply.

Optimal sampling times for OIH-clearance calculations using a two-compartment/two-sample method

Orthoiodohippurate (OIH) clearance data obtained with the two-compartment/two-sample method of Lear which uses varying sampling time combinations, were compared with those of the reference two-compartment/multi-sample method of Sapirstein. A total of 35 studies were performed in 33 adult patients. The OIH clearance values determined by the reference method ranged from 107 to 883 ml/min/1.73 m2, with a median of 406 ml/min/1.73 m2. It was ascertained that the precision of the Lear method is partially dependent upon the sampling time combination. The most reliable results with the Lear method in this patient population were obtained by taking a first sample at approximately 8 min p.i., and a second sample at 32 min p.i. or later.

The impact of W. K. Röntgen's discovery on the use of internalizable sources of ionizing energy in diagnostic and therapeutic nuclear medicine

The early history of cathode rays, X-rays and a third kind of natural radiation from several minerals and atomic fission is described. In this way the fundamental concept of radioactivity, laws of decay and atomic models were developed. With artificial radioactive isotopes, new tailored radiopharmaceuticals could be introduced into metabolic research, medical diagnostics and therapy. Von Hevesy's concept of the dynamic state of body constituents led to examination of the locations and movements of labelled atoms and molecules as a function of time. That was the birth of nuclear medicine. The principles and value at the molecular level of several specific tracer studies in research and diagnostic or therapeutic use are explained. Typically, diagnostic tests with tracer agents are non-invasive and have low radiation exposure. Competing with other diagnostic and therapeutic modalities, nuclear medicine is a speciality in its own right. But there are moves to classify it as a subspecialization of other organ-oriented clinical disciplines. That is a misunderstanding of the radiologist's role and does not answer the question: What is the best way of working for the patient? New horizons in diagnostic modalities, biochemistry, immunology, imaging and the use of immunogenic therapeutic agents demand a continuous cooperation within interdisciplinary teams. That is as necessary with radiologic departments, participating in changed organizational structures, as with other clinical departments.

The instability of dietary iodine supply over time in an affluent society

In the Bernese region, where goiter was formerly endemic, alimentary salt has been supplemented by increasing amounts of potassium iodide (KI): 5, 10, 20 mg KI/kg in 1922, 1965 and 1980 respectively. Ioduria rose from < 30 micrograms I/g creatinine in 1920 to > 100 micrograms I/g creatinine in the 1980s. In 1992 ioduria was estimated in 55 healthy volunteers (group A and individual B) and 234 thyroid carcinoma patients after thyroidectomy: hypothyroid patients with (C) and without thyroid remnants (D) and euthyroid patients on T4 substitution (E). The arithmetic mean iodine excretion of the healthy volunteers in group A and individual B was found to be 87 +/- 40 micrograms I/g creatinine. This is insufficient according to the recommendations of the WHO. In all groups, the iodine excretion reached the recommended level only in some members: 24% (A, B), 19% (C), 38% (D) and 81% (E). It was thought in the 1980s that in a formerly iodine-deficient society, iodinated salt would continue to provide an adequate supply of iodine. However, iodine intake in this affluent society has proved to be unstable. This can be attributed to modifications of eating habits, which include a reduction of total salt consumption, combined with a growing consumption of manufactured food of cosmopolitan origin, prepared using salt containing little or no iodine.

Immunogenic and non-immunogenic hyperthyroidism. Recent trends in prealpine Switzerland and in coastal Poland

Annual occurrences of immunogenic (IH) and non-immunogenic hyperthyroidism (NIH) between Berne (1976, 1982, 1991) and Szczecin (1973, 1980, 1991) were compared. Out of 21,025 patients referred for thyroid examinations, 10.1% (average) were hyperthyroid. In Berne (former endemic goiter region) and Szczecin (without goiter endemicity) IH occurred in 41% and 68%, NIH in 59% and 32% of hyperthyroid patients, respectively. Within a stable incidence of NIH in Berne, toxic adenomas (TA) decreased from 41% (1976) to 17% (1991) (p < 0.005). In Szczecin, where iodine deficiency is in an early stage, the TA frequency did not change significantly: from 24% (1973) to 28% (1991). Increases of TA or of multifocal functional autonomy apparently "mark" incipient or, respectively, decreasing deficiencies in nutritious iodine. Hyperthyroid patients in Berne compared to Szczecin were older, both with IH (54 versus 45 y) and NIH (65 versus 52 y). Age at diagnosis was stable in Berne but increasing (p < 0.05) in Szczecin (from 43 to 52 y).

Congestive hypersplenism: treatment by means of radioembolization of the spleen with Y-90

Radioembolization of the spleen with yttrium-90 was performed in a patient with severe thrombocytopenia attributable to congestive hypersplenism. Follow-up included performance of serial contrast material-enhanced computed tomographic studies for 13 months. Splenic volume decreased from 1,400 to 470 cm3. The platelet count increased to almost normal levels. No complications were observed. Splenic radioembolization merits further investigation in selected patients.

Somatostatin receptor scintigraphy in central nervous system tumors: role of blood-brain barrier permeability

Somatostatin receptors are expressed in meningiomas and low-grade gliomas, raising the hope that scintigraphy with 111In-DTPA-D-Phe1-octreotide might be helpful in the in vivo localization, differential diagnosis and postoperative/postradiotherapy brain tumor follow-up.

METHODS

Indium-111-DTPA-D-Phe1-octreotide scintigraphy and brain scintigraphy using 99mTc-DTPA as a nonspecific tracer for blood-brain barrier integrity were simultaneously performed in 60 patients with CNS tumors using dual-isotope acquisition mode SPECT. For 23 patients, the scintigraphic findings were also compared with in vitro somatostatin receptor autoradiography of surgical biopsy specimens.

RESULTS

In meningiomas (located outside the blood-brain barrier), the somatostatin receptor scan showed all tumors and scintigraphic signal intensity correlating with in vitro SSR density positive in all meningiomas. Less contrast was seen on 99mTc-DTPA scans. In all tumors inside the blood-brain barrier, the 111In-DTPA-D-Phe1-octreotide scan visualized the tumors with a disrupted blood-brain barrier, as seen by 99mTc-DTPA scintigraphy. Discrepancies, however, were observed between somatostatin receptor scintigraphy and in vitro receptor autoradiography.

CONCLUSION

Combined somatostatin receptor and 99mTc-DTPA scintigraphy may be helpful for noninvasive differentiation between meningiomas and other CNS tumors. False-negative scans were observed as a result of shielding by the intact blood-brain barrier. Interpretation of negative and positive somatostatin receptor scans in CNS tumors must therefore be done with caution.

[Methods for the superselective radioembolization of liver tumors with 90yttrium-resin particles]

An improved technique for radioembolization of non-resectable liver tumours is described. 90yttrium-labelled Bio-Rex-70 particles which show high stability and good tissue tolerance are applied superselectively via the tumour-feeding artery using a microcatheter. The procedure includes both diagnostic and therapeutic angiography. Angiography is complemented by angioscintigraphy (99mTc-MAP) and an i.v. 99mTc-colloid scan of the liver. Thus it is possible pretherapeutically to evaluate tumour volume and dose distribution both in and outside of the liver, and in the lung due to shunt. These estimates were re-evaluated posttherapeutically. Radioembolization can thus be quantified and the doses absorbed by the tumour as well as the liver and lung can be calculated.

Superselective radioembolization of hepatocellular carcinoma: 5-year results of a prospective study

Twenty patients with unresectable hepatocellular carcinoma (HCC) were followed up to 5 years after transarterial radiotherapy with 90Y-resin particles. Diagnostic radioembolizations of 99mTc-macroaggregates facilitated scintigraphic assessment of activity distribution, dose evaluation and final procedural verification. The overall survival rates were 56, 38 and 14% (after 1, 2 and 3 years, resp.). Patients with unifocal HCC and a single feeding artery (n = 7) even presented 83, 67 and 40% (2 alive after 2.75 and 4 years). With multiple arteries (n = 7), the longest survival was 26 months. Patients with multifocal HCC survived up to 33 months after selective radioembolization. Quality of life was improved in all. Survival was positively correlated with absorbed dose but residual/recurrent tumour occurred even after > or = 300 Gy. Post-treatment symptoms were minimal (35 applications), pulmonary shunt rates were correctly predicted and pulmonary complications avoided.

Dual-isotope SPET 201Tl rest/99mTc-MIBI stress: one-day protocol for pre-operative myocardial imaging?

We compared the results of a rest 201TI/stress 99mTc-MIBI protocol, both by means of separate single isotope and simultaneous dual isotope acquisition, with a standard stress/rest 99mTc-MIBI 2-day protocol in 11 patients with low probability of CAD and 14 patients with chronic CAD. In patients with CAD 406 segments (sgs) were analysed. In the standard protocol 119 sgs were classified as pathological of which 50.4% were fixed and 49.6% reversible defects. With the MIBI-stress/TI-rest single 33% of 119 pathological sgs were fixed and 67% reversible defects. With the MIBI-stress/TI-rest dual only 20% were fixed and 80% reversible defects. The reversibility of 59 MIBI-stress/MIBI-rest reversible defects was quantified: MIBI-stress/MIBI-rest 35 +/- 16% MIBI-stress/TI-rest single 50 +/- 26% and MIBI-stress/TI-rest dual 48 +/- 22%. The results of 99mTc-MIBI rest and 201TI rest studies in patients with chronic CAD are not the same. Dual-isotope 1-day 201TI-rest/99mTc-MIBI-stress SPET data, acquired separately, may give fast and complete information on myocardial perfusion at stress and rest, respectively, and on myocardial viability.

Dual-Isotope SPET201T1 Rest/99mTc-MIBI Stress: One-Day Protocol for Pre-Operative Myocardial Imaging?

We compared the results of a rest 201TI/stress 99mTc-MIBI protocol, both by means of separate single isotope and simultaneous dual isotope acquisition, with a standard stress/rest 99mTc-MIBI 2-day protocol in 11 patients with low probability of CAD and 14 patients with chronic CAD. In patients with CAD 406 segments (sgs) were analysed. In the standard protocol 119sgs were classified as pathological of which 50.4% were fixed and 49.6% reversible defects. With the MIBI-stress/TI-rest single 33% of 119 pathological sgs were fixed and 67% reversible defects. With the MIBI-stress/TI-rest dual only 20% were fixed and 80% reversible defects. The reversibility of 59 MIBI-stress/ MIBI-rest reversible defects was quantified: MIBI-stress/MIBI-rest 35 ± 16% MIBI-stressl-rest single 50 ± 26% and MIBI-stress/TI-rest dual 48 ± 22%. The results of 99mTc-MIBI rest and 201TI rest studies in patients with chronic CAD are not the same. Dual-isotope 1-day 201TI-rest/99mTc-MIBI-stress SPET data, acquired separately, may give fast and complete information on myocardial perfusion at stress and rest, respectively, and on myocardial viability.

[Risk factors in papillary thyroid cancer]

270 patients with papillary thyroid carcinoma were retrospectively analyzed. The mean age at initial diagnosis was 43.5 years. 74% of the patients were females. 15 patients (6%) had residual tumor after initial surgery and 61 patients (24%) showed recurrent disease. The recurrence was discovered clinically, radiologically and by increasing thyroglobulin levels in 72%, 23% and 5% of the patients, respectively. Recurrent disease was located in the tumor bed, locally and metastatic and only metastatic in 61%, 23% and 16% of the patients, respectively. After a mean follow-up of 9.4 years (range 3-20 years) the overall mortality was 13%. 6% of the patients died from tumor, 3% with tumor and 4% without tumor. 46% of patients with residual tumor died from tumor progression, in contrast to 18% of patients with early recurrence (< 5 years) and 6% of patients with late recurrence (> 5 years). We conclude that papillary thyroid carcinoma has a low mortality (6%) even in an endemic area. Patients with residual tumor after initial surgery and patients with early recurrence have an increased cancer mortality.

[Long-term course in differentiated thyroid gland carcinoma]

545 patients with differentiated thyroid carcinoma were followed up for periods ranging up to 25 years after first treatment (mean 8.1 years, 65% for over 5 years). 72% of patients with papillary carcinoma (n = 270), but only 52% with follicular carcinoma (n = 275) remained tumor-free during the further course. Residual malignancies persisted for more than the first year in 6% and 17% of patients respectively; there were tumor recurrences after an apparently tumor-free interval in 22% and 31% respectively, the latest after 12 and 27 years respectively. 6% and 19% of patients respectively died as a direct result of the tumor (and a group of equal size from other causes), half due to residual and half due to recurrent carcinoma. With regard to residual tumors, few significant risk factors were found preoperatively, comprising distant metastases (factor = 34 and 20 for papillary and follicular tumors respectively), age over 50 years (F = 6.4 and 5), infiltrating growth of primary tumor (F = 4 and 4.3), and regional lymph node involvement (F = 1.2 and 2). However, these factors were of little use in predicting the risk of the more frequently observed tumor recurrence, with maximum factors of 2 (for T4 and N+ stage) for papillary thyroid cancers and 1.5 for follicular cancers. At risk for recurrence were patients in whom total thyroidectomy was not performed (F = 2.3 and 2) and those who did not receive postoperative radioiodine treatment (F = 3), irrespective of age and tumor stage. Therefore, any individualizing regimen beginning with the first treatment has a bearing not only on residual tumor's 50% contribution to mortality. The equally large contribution of recurrences to tumor death can be influenced only by thyroidectomy or, more realistically, by strumectomy combined with early ablation of thyroid remnants with radioiodine. Postoperative radiotherapy of the neck region did not prevent tumor recurrence, and although hormonal suppression was never given the results compared well with the best of published long-term follow-up studies. There were no acute or late complications that could be ascribed to radioiodine treatment. However, a strict strategy of the reducing the administered doses was adopted: the ablation dose was half that used previously (1.5 GBq, i.e. 45 mCi on average), tumor treatment was halted even where residual uptake was observed scintigraphically (in 44% of patients treated) and radioiodine was no longer used for follow-up investigations.(ABSTRACT TRUNCATED AT 400 WORDS)

90Y-resin particles--animal experiments on pigs with regard to the introduction of superselective embolization therapy

Resin particles (diameter 45-75 microns) were labelled with 90Y, suspended in a glucose/dextran solution and infused into the kidneys of 3-month-old pigs (tumour model). Both kidneys of each animal were embolized with particles, but only one with active (90Y loaded) particles and the other, for comparison, with inactive particles. The organ measurements showed less than 1% of injected activity in bone, bone marrow, liver and lung compared to greater than 99% retention by the kidneys. Only minimal shunted activity was found in blood (less than 0.27%) and urine (less than 0.07%). There was a clear shrinkage of the 90Y-treated kidneys with a reduction in weight of up to 50%. Histologically, the ischaemic lesions (infarcts and atrophy) were clearly more pronounced and extensive in the 90Y-embolized kidneys than in the non-radioactive embolized kidneys. Furthermore, severe arterial wall changes and fibrotic necrosis due to radiation damage were observed in the 90Y-treated kidneys. It is concluded that with intra-arterially applied particles a dose of about 100 Gy is sufficient to completely destroy tissue-specific structures. Complications due to acute necrosis or inflammatory reactions were not observed, and there were no shunt related alterations seen in the liver or lungs. The 90Y-loaded resin particles are considered suitable for a super selective intra-arterial radioembolization.

Routine 18F-2-deoxy-2-fluoro-D-glucose (18F-FDG) myocardial tomography using a normal large field of view gamma-camera

There is a recent need to study glucose metabolism of the heart in ischemic, as well as in "hibernating or stunned" myocardium, and compare it with that in perfusion studies. In non-positron emission tomography centers, positron imaging is possible with a standard Anger-type camera if proper collimation and adequate shielding of the camera crystal can be achieved. For the study with fast-decaying isotopes, seven-pinhole tomography (7PHT), a limited-angle method designed for transaxial tomography of the left ventricle using a nonrotating camera, is well suited, because projections are acquired simultaneously. Individual adjustment (patient supine) of the camera's view axis (CAx) with the left ventricular axis (LVAx) gives excellent results: sensitivity for CHD 82%, specificity 72% in a prospective 201TI study (48 patients, x-ray coronarography as reference). Good alignment of CAx with LVAx is also achieved with the patient prone in LAO in a hammock above the camera surface. In this setting additional lead shielding of the camera is possible using a table reinforced with 5 cm of lead with a central hole for the 7PH-collimator, which has a special lead inlay. This allows utilization of the 511 KeV emitter 18F-FDG, which with a half-life of 109 minutes, can be transported a reasonable distance from the production site. System sensitivity and resolution for 18F was found comparable to 201Tl, 99mTc, and 123I using a phantom. First clinical examinations after 201Tl stress/redistribution studies showed increased 18F-FDG uptake in ischemic heart segments, as well as in "hibernating" nonperfused or "stunned" myocardium.

[Radioimmunoscintigraphy with a 99mTc-labeled F(ab')2 fragment of a monoclonal antibody (HMW-MAA 225.28S) in 71 patients with malignant melanoma]

In 71 patients with malignant melanoma 85 radioimmunoscintigraphies (RIS) with 99mTc-radiolabeled F(ab')2 fragments of a murine monoclonal antibody have been performed. The antibody is specific for an epitope of the HMW-MAA glycoprotein complex which is present in 90% of melanoma tissue samples. Sensitivity for RIS was 79% (73 metastatic sites out of a total of 92). 20 previously unknown lesions were found and there were also 2 false positives. Conventional staging procedures alone revealed 78% of the metastatic sites (72 of 92). No side effects were observed. RIS was especially useful for detection of lymph node metastases not found by conventional methods and is therefore considered complementary to conventional preoperative staging procedures.

[Immunoscintigraphy with 99mTc marked melanoma antibody in patients with malignant melanoma]

In 38 patients with malignant melanoma 44 radioimmunoscintigraphies (RIS) with 99mTc labeled F(ab')2 fragments of an anti-melanoma monoclonal antibody (225.28S, Tecnemab-K, Sorin Biomedica) have been performed. No side effects have been observed even in the patients with repeated RIS. Overall 81% (35/43) of all lesions were detected by imaging and 9 lesions have been previously unknown. Sensitivity and specificity was highest for lymphnode metastases with 100% each. Poor imaging was observed in lung and mediastinal metastases (2/7) as well as small skin metastases. RIS has to be studied for its clinical value in staging of lymphnode metastases preoperatively in patients undergoing regional lymphnode dissection.

Comparative diagnostic value of a new computerized vectorcardiographic method (cardiogoniometry) and other noninvasive tests in medically treated patients with chest pain

The diagnostic value of cardiogoniometry (CGM), a new computerized vectorcardiographic method, for the identification of coronary artery disease was compared with other noninvasive tests in 48 medically treated patients with chest pain. Coronary angiography revealed one-vessel disease in 18, two- or three-vessel disease in 21, and normal coronary arteries in 9 patients. Cardiogoniometry was less sensitive (63%) than thallium-201 (201T1) scanning (82%), but slightly more sensitive than the exercise ECG (50%) or a recently proposed parameter of exercise performance (50%). On the other hand, specificity was comparable among these tests (exercise ECG 78%, thallium-201 scanning 72%, CGM 67%, new parameter of exercise performance 66%). Moreover, the false negative rate of noninvasive testing was reduced from 8 to 3% when CGM was added to thallium-201 scanning and exercise ECG. Our findings indicate that in view of the easier feasibility with computerized technology, the future role of vectorcardiographic methods such as CGM in the noninvasive diagnosis of coronary artery disease should be redefined.

[Circadian rhythm of parathyrin and calcitonin concentrations in the serum]

The circadian variations of serum intact parathyrin, C-terminal parathyrin (65-84), mid-region parathyrin (44-68) fragments, calcitonin, total calcium, ionized calcium, albumin and phosphate were measured in five healthy subjects. Intact parathyrin, parathyrin (44-68) and calcitonin show a synchronous diurnal fluctuation with a nocturnal increase to a maximum between 24.00 and 2.00 hours. Whereas phosphate has a marked circadian rhythmicity with a zenith between 1.00 and 8.00 hours, total calcium and albumin show a tendency to decrease between 20.00 and 6.00 hours. Ionized calcium concentration remains constant over the whole day.

On the prognostic potential of the sequential 123-I-HDA-tomoscintigram after the first MI

Seven-pinhole tomography (SPT) using 123-I-heptadecanoic acid (HDA) is highly sensitive in confirming, sizing and localizing myocardial infarcts (MIs). Its prognostic value, however, is unknown. Thirty-five consecutive patients coming for a routine SPT within 10 days after MI underwent a second examination approximately 20 weeks later. These examinations combined an early (5 min) and a late (30 min) SPT after administration of 4 mCi 123-I-HDA, as well as a first pass radiocardioangiography. Scars and infarcts without residual HDA catabolism were related to lesions which followed (from 5 min to 30 min) a cool-cool or cold-cold behaviour. Cool-warm lesions (due to low HDA uptake and prolonged washout) were considered ischaemic. This ischaemic behaviour could not be correlated to the later course of the illness: in those patients with higher initial ischaemic scores, the ejection fraction did not increase disproportionately nor was the size of the lesion significantly smaller in the later examination than in those patients with lower ischaemic scores. Only a slightly better reduction of the end-diastolic volume was found in the patients with initially predominantly ischaemic lesions. Thus, SPT with HDA seems to be of limited value for an early prognostic evaluation of patients with MI.

A modification of the 133Xe inhalation method for the measurement of liver blood flow in man

The 133Xe inhalation technique for liver blood flow measurements was modified by using a gamma camera for data acquisition. Desaturation curves were derived from regions of interest (ROIs) over different parts of the liver, the lung and that lung area overlapping the liver, the liver hilus, and the splanchnic area. An additional liver scan with 99mTc-sulfur colloid facilitated the choice of these regions and allowed the estimation of the total liver volume. Thirteen healthy volunteers were examined under baseline conditions. Uncorrected blood flow values derived from the 133Xe-washout curves over the liver (40 +/- 10 ml/min/100 g liver) were lower than those found with other methods. A multicompartment model, based on the input functions calculated from the lung and splanchnic curves, gave values in accordance with those reported in the literature (94 +/- 20 ml/min/100 g or 1,356 +/- 382 ml/min/liver; mean liver volume: 1,475 +/- 227 g). Some methodologic limitations are shared with other invasive or noninvasive techniques.

Preoperative localization of parathyroid tumors by 201Tl/99mTc subtraction scanning

29 patients with biochemically proven hyperparathyroidism underwent a 201Tl/99mTc subtraction scanning before neck exploration was done. The scanning technique seems not to be reliable for hyperplastic glands in secondary hyperparathyroidism, but in 19 of 21 patients with primary hyperparathyroidism a solitary adenoma was correctly located. This accuracy of 90.5% justifies to investigate all patients with primary hyperparathyroidism with this noninvasive double tracer technique prior to any surgery.

Radionephrographic follow-up with hypertensive patients after angioplasty of renal artery stenosis

Radionephrographies were performed in 23 hypertensive patients before and after 28 transluminal dilatations (PTD) of their stenosed renal arteries. The changing clearances for both kidneys (global = Clgl) and for stenosed and contralateral kidneys (Clst and Clco) were followed for three groups, dependent on their clinical outcome, as well as the parenchymal transit time (re-entry time) for the diseased (Rtst) and contralateral kidneys (Rtco): (A) Normalized hypertension: for 9 patients the preoperative Clco was never lower than 150 ml/min, but increased significantly after PTD. Rtst fell significantly, Rtco remained constant. Mean increase in Clgl = 91 ml/min (+25%). (B) Improved hypertension: in 12 patients Clst and Clco had been lower than with those in group A; postoperatively Clst increased, Rtst fell significantly. The Rtco was prolonged early after PTD but normalized later. (C) Permanent hypertension: for 7 of these patients there were no preoperative criteria for a discrimination against the other groups. But in all Rtst did not normalize, and Rtco increased early after PTD. Even in later examinations Rtco remained higher than preoperatively. These results imply that the success of PTD depends mainly on the behavior of the contralateral kidney. The examination 1 day after the PTD gives an optimal prognosis concerning the end result.

[Nuclear medical diagnosis of pulmonary embolism]

Lung perfusion scintigraphy can make arterial embolic obstruction visible because the uptake of microspheres labelled with 99mTc is lower than normal in the corresponding lobes, segments or subsegments. The sensitivity for pulmonary embolism is high (up to 98%). The specificity of a positive finding increases with additional investigations: infiltrative and space occupying lesions can be seen on the chest X-ray, and broncho-obstructive diseases with concomitant perfusion defects can be identified with the help of ventilation scintigraphy using 133Xe. In view of its high sensitivity and specificity, its low cost, low risk with practically no discomfort for the patient, and standardized techniques not dependent on the skill of the examiner, lung scintigraphy can replace pulmonary angiography in nearly all circumstances. It should be noted, however, that late sequelae--after thrombolysis and recanalization have taken place and when atelectases or pneumonia may dominate--may blur the scintigraphy findings. Thus, patients must be sent for lung scintigraphy as soon as suspicion of pulmonary embolism arises.

[Hyperthyroidism in thyroid cancer. Retrospective study of 53 cases]

Hyperthyroidism was diagnosed in 53 of 273 thyroid carcinoma patients at the time of their first examination (between 1971 and 1983). This corresponds to 19.5% of these mainly well-differentiated thyroid cancers. In 24 (45%) patients the hyperthyroidism and the thyroid carcinoma were two separate distinct illnesses: of 4 patients with Graves' disease (1.5% of 273), 2 had been operated because of an additional solitary cold nodule, and in the other 2 an occult carcinoma was found intraoperatively. Twenty patients of this group had Plummer's disease: there was a malignant cold nodule within a multinodular goiter with multifocal functional autonomy (MFA)(n = 14) or a carcinoma located near the solitary hot nodule of the toxic adenoma (TA)(n = 6). In these patients the distribution of the different histologies was about the same as in other thyroid cancer patients from this region. The remaining 29 patients (55%) had Plummer's disease, 28 with the classical finding of a solitary toxic adenoma, in which the hot nodule and the malignant tumor were identical. It was possible to confirm this identity histologically in 10 out of 24 cases, retrospectively. Eight of these patients had metastases with radioiodine uptake at the time of the first examination. Of the tumors in this group, 24 were follicular and 5 papillary carcinomas. As a rough estimate, one malignant, scintigraphically hot tumor is found for every 50 benign toxic adenomas. Criteria for the differentiation are: recent growth of the nodule, tumor size of greater than 5 cm diameter or greater than 35 g and an elevated T3-level of less than 0.06 nmol/l/g tumor.(ABSTRACT TRUNCATED AT 250 WORDS)