Quantitative assessment of intravascular volume of the human Achilles tendon.

The pathogenesis of Achilles tendon rupture remains unclear, but vascular patterns may play an important role. We determined the intravascular volume of the Achilles tendon using a new method with injection of radioisotopes. A solution of Tc-99m and gelatin-ink was injected into the lower limbs of body donors. The intravascular volume of each 1 cm section of the Achilles tendon was measured using a gamma well counter. We found that the distal part of the Achilles tendon (0-2 cm above the calcaneus) had an intravascular volume of 59-98 microL/g tendon tissue. In the middle part of the tendon (3-6 cm above the calcaneal insertion), the intravascular volume was much less: 2743 microL/g tissue. The proximal part of the tendon (7-9 cm) had an intravascular volume between 51-100 microL/g tendon tissue. The reduced vascularization in the middle part of the human Achilles tendon may play a role in degeneration and spontaneous rupture of the tendon.

Radioprotection of salivary glands by amifostine in high-dose radioiodine therapy.

UNLABELLED: Salivary gland impairment after high-dose radioiodine treatment is well recognized. Because differentiated thyroid cancer has a good prognosis, reduction of long-term side effects is important. This study investigated the radioprotective effects of amifostine in animals and humans receiving high-dose radioiodine therapy. METHODS: Quantitative salivary gland scintigraphy was performed in five rabbits before and up to 3 mo after high-dose radioiodine therapy applying 1 GBq 131I. Three animals received 200 mg/kg amifostine before high-dose radioiodine therapy, and two served as controls. All animals were examined histopathologically. Quantitative salivary gland scintigraphy also was performed in 17 patients with differentiated thyroid cancer before and 3 mo after high-dose radioiodine therapy with 6 GBq 131I. Eight patients were treated with 500 mg/m2 amifostine before high-dose radioiodine therapy, and nine served as controls. RESULTS: In two control rabbits, high-dose radioiodine therapy significantly reduced parenchymal function by 63% and 46% in parotid and submandibular glands, respectively. In contrast, there was no significant decrease in parenchymal function in amifostine-treated animals. Histopathologically, lipomatosis was observed in control animals but was negligible in amifostine-treated animals. Similar findings were observed in differentiated thyroid cancer patients. In nine control patients, high-dose radioiodine therapy significantly (p < 0.01) reduced parenchymal function by 37% and 31% in parotid and submandibular glands, respectively. Three patients exhibited Grade I (World Health Organization) xerostomia. In contrast, there was no significant decrease in parenchymal function in amifostine-treated patients and no incidence of xerostomia. CONCLUSION: Parenchymal damage in salivary glands induced by high-dose radioiodine therapy can be reduced significantly by amifostine. This may increase the quality of life of patients with differentiated thyroid cancer.

Quantification of diphosphonate uptake based on conventional bone scanning.

Up to now there has been no routinely used and easy-to-perform method for the quantification of bone uptake. Therefore, we have evaluated the clinical practicability of a new and simple method for the measurement of bone uptake based upon conventional three-phase bone scanning. In 13 patients with normal bone scans, whole-body scintigrams were obtained at 3 min and 1, 2, 3, 4, 5, 6 and 24 h after injection of 600 MBq technetium-99m hydroxymethylene diphosphonate (HMDP). Using a conventional region of interest technique, fitted time-activity curves of soft tissue and urinary excretion were established, and bone uptake was calculated from these data as the total whole-body activity minus both soft tissue activity and urinary excretion. Subsequently, the new method was tested in routine patient management: 32 healthy patients and five patients with different types of metabolic bone disease were investigated, measurements being performed only at 3 min and 3-4 h p. i. during conventional three-phase bone scanning. In the multi-imaged patient subset, soft tissue activity decreased exponentially, reaching a plateau after 6 h with a residual activity of about 14% of initial total whole-body activity. Bone uptake reached quite a stable plateau of about 27% as early as 3 h p.i., with no significant changes up to 24 h. Healthy patients of the two-scan group showed no differences in bone uptake (mean uptake values were 24.1% in women and 26.9% in men), whereas in patients with metabolic bone disease bone uptake was significantly higher, with a mean of 48% (P <0.05). Thus, the results of this method are in good agreement with the findings of standard 24-h whole-body retention measurements. The new method, however, is easy to perform, allows assessment of pure bone uptake instead of whole-body retention, and permits calculation of bone uptake by only two measurements during routine three-phase bone scanning.

[Quantitative salivary gland scintigraphy--a recommended examination prior to and after radioiodine therapy]. / Die quantitative Sialoszintigraphie--eine sinnvolle Untersuchung im Vorfeld und in der Nachsorge der Radiojodtherapie.

AIM: The aim of this study was to evaluate possible deterioration of salivary gland function due to radioiodine therapy with low activities using standardized quantitative salivary gland scintigraphy (qSZ). In addition, the prevalence of sialopathies was estimated in patients with thyroid dysfunction. METHODS: Prior to routine thyroid scintigraphy qSZ was performed after i.v. injection of 36-126 MBq 99mTc-pertechnetate, and both uptake and excretion fraction were calculated as a measure of parenchymal function and saliva excretion, respectively 312 healthy patients served as reference for a normal data base. 144 patients underwent qSZ prior to and 3 months after radioiodine therapy. Results of qSZ in another 674 thyroid patients were evaluated for determining the prevalence of salivary gland dysfunction. RESULTS: Normal uptake was 0.45 +/- 0.14% and 0.39 +/- 0.12%, and normal excretion fraction amounted to 49.5 +/- 10.6% and 39.1 +/- 9.2% in parotid and submandibular glands, respectively. Despite salivary gland stimulation with ascorbic acid during radioiodine therapy a significant activity-related functional impairment of 14-90% could be measured after application of 0.4-24 GBq of 131I. Prevalence of pretreatment sialopathies was 77/674 = 11.4% in single glands, and there was a global salivary gland functional impairment in 52/674 = 7.7%. CONCLUSION: Together with thyroid scintigraphy qSZ is an easy to perform examination without additional radiation burden. It can be recommended in all patients prior to and after radioiodine therapy both in order to quantify and to document possible parenchymal impairment induced even by low activities of 131I.

[Lymphoscintigraphy with double tracer technique in carcinomas of the head-neck region]. / Lymphszintigraphie in Doppeltracertechnik bei Karzinomen im Kopf-Hals-Bereich.

BACKGROUND: Lymphoscintigraphy has been used since the early 1960s to demonstrate lymphatic drainage of head and neck tumors, but did not prove satisfactory. With the increasing importance of highly sophisticated neck dissection procedures, lymphoscintigraphy may have greater diagnostic impact. This assumes that lymphoscintigraphy will allow an accurate correlation of lymphatic drainage with anatomic structures. In this paper, we report on a method of lymphoscintigraphy with simultaneous body contouring. METHODS: Double-tracer lymphoscintigraphy was performed in 78 patients with squamous cell carcinoma. Patients received 100 MBq 99mTc-colloid in 0.1-0.2 ml in 3-4 peritumoral localizations. Ten patients were injected during surgery. Two milliliters of perchlorate solution were given orally in order to block the thyroid. Twenty minutes later patients received 50 MBq 99mTc-pertechnetate i.v. for body contouring. Planar images were obtained over 5 min each at 30 min and 4-6 h after injection from anterior, right lateral and left lateral using a LFOV-gamma camera. RESULTS: The thyroid was not visualized in any of the patients. In 28 of 78 patients (36%), the injection site was the only focal activity seen. In 50 of 78 patients (64%), lymph drainage was observed. Thirty-six of 78 patients (46%) showed unilateral lymphatic drainage, and 14 of 78 (18%) showed bilateral drainage. In all 50 patients showing lymphatic drainage, lymph nodes could be easily assigned to the six cervical lymph node compartments described. CONCLUSIONS: Double-tracer lymphoscintigraphy enables an accurate correlation of cervical lymph nodes and anatomic structures of the head and neck region. These findings suggest that the impact of these studies on the preoperative planning for neck dissection should be reevaluated.

[Implementation and indications for quantitative sialoscintigraphy]. / Durchführung und Indikationen der quantitativen Sialoszintigraphie.

BACKGROUND: Since its introduction in 1965 salivary gland scintigraphy has been an established method to simultaneously investigate excretion function in major salivary glands. In order to elucidate parenchymal function of salivary glands, several authors described various quantitative and semiquantitative methods. However, no standardized protocol for quantitative salivary gland scintigraphy has been established so far. METHODS: Therefore, in this paper we report on a standardized and validated acquisition protocol for salivary gland scintigraphy using 99mTc-pertechnetate. RESULTS: A normal data base for both parenchymal and excretion function is given in detail. In addition, the diagnostic value of salivary gland scintigraphy is reviewed in various clinical settings, such as mild parenchymal damage in beginning Sjögren's syndrome, proof of functional obstruction in sialolithiasis with and without parenchymal damage, and parenchymal damage following radioiodine treatment. In a second part, applications of salivary gland scintigraphy in current clinical research are described, and radiation protection of salivary glands in rabbits and patients treated with high doses of I-131 are discussed. CONCLUSIONS: Salivary gland scintigraphy is a study that is easily performed and well tolerated by the patient. It yields quantitative parameters for parenchymal function and excretion fraction.

Quantitative salivary gland scintigraphy in the diagnosis of parenchymal damage after treatment with radioiodine.

This study was undertaken to quantify salivary gland parenchymal damage after radioiodine treatment with a standard protective regimen of ascorbic acid. Altogether, 106 patients underwent quantitative salivary gland scintigraphy with 99Tcm-pertechnetate prior to and 3 months after radioiodine therapy. Parenchymal function was quantified by calculating 99Tcm-pertechnetate uptake 13 min post-injection. Patients received 131I doses ranging from 400 MBq to 24 GBq (cumulative). Among the patients who received large doses of 131I, severe parenchymal destruction could be visually analysed as well as quantitatively evaluated. In contrast, after low-dose radioiodine treatment, mild parenchymal impairment was demonstrated by quantitative evaluation only. In conclusion, standardized quantitative salivary gland scintigraphy is essential for the reliable detection of mild parenchymal malfunction. Despite the standard protection regimen using ascorbic acid as a sialogogue, radioiodine therapy induces loss of salivary gland parenchymal function even with low doses of 131I.

The value of bone scanning in pre-operative decision-making in patients with progressive facial asymmetry.

Hemimandibular elongation is characterized by persistent unilateral growth, resulting in unilateral overgrowth of the mandible. The surgical treatment strategy depends on condylar growth activity, which cannot be assessed by conventional radiological procedures. Therefore, this study was undertaken to evaluate the usefulness of bone scanning in hemimandibular elongation. Twenty-seven patients underwent bone scanning prior to surgery. Growth activity was quantified by calculating the L/R ratio. In the case of more pronounced right-sided growth producing a L/R ratio of less than 1, inverse values were used. Corrective osteotomy was performed in the patients with a L/R < 1.10, whereas patients with a L/R > 1.10 underwent condylectomy. Twenty-three patients had a L/R ratio < 1.10 and were followed up for 3 years. In 16 patients, a corrective osteotomy was performed without any relapse post-operatively. Four patients showed marked unilateral increased uptake. In one patient, a pre-operative bone scan was not considered, and corrective osteotomy was performed with subsequent recurrence of unilateral overgrowth of the mandible. The final patient underwent condylectomy without relapse. In two patients, it was decided to repeat the bone scan after a follow-up period of 12 months. In conclusion, bone scanning has significant clinical value in pre-operative decision-making in hemimandibular elongation by guiding surgical strategy with respect to condylar growth activity.

Somatostatin receptor scintigraphy in the differential diagnosis of meningioma.

The aim of this study was to evaluate somatostatin receptor scintigraphy (SRS) in patients with meningioma proven or suspected on magnetic resonance imaging (MRI). Prior to surgery, 47 patients were investigated up to 24 h following the injection of 200 MBq 111In-octreotide. Tracer uptake was compared with the histological presence of meningioma. Histology revealed 43 meningiomas, 3 neurinomas and 1 ependymoma. A true-positive SRS result was obtained in 36 patients, in 13 of whom a tumour volume of < 10 ml was noted. A false-negative SRS result was obtained in seven patients, all of whom had a tumour volume of < 10 ml. Whereas MRI alone was decisive in 38 of 47 patients, it could only provide a differential diagnosis in the remaining 9 patients. A positive SRS result confirmed meningioma in five of these patients, and a negative SRS result excluded meningioma in the other four. Therefore, cases of SRS-negative meningioma do exist. Nevertheless, significant clinical benefit can be obtained from functional imaging with 111In-octreotide in patients with an inconclusive MRI result, as large meningiomas can be excluded by scintigraphy alone, whereas meningiomas of any size may be confirmed in combination with specific MRI results.

Somatostatin receptor scintigraphy in the staging of small cell lung cancer.

The aim of this study was to evaluate somatostatin receptor scintigraphy (SRS) in the staging of patients with small cell lung cancer. Prior to chemotherapy, 20 patients were investigated up to 24 h following an injection of 200 MBq 111In-octreotide. Following chemotherapy and restaging, four patients were re-evaluated. Primary tumour was detected in 18 of 23 studies, which exhibited increasing target-to-back-ground ratios over time. Lymph node metastases and distant metastases were detected in 7 of 27 and 8 of 31 sites, respectively. Thus, the overall sensitivity for detecting metastases was less than 26%. SRS did not result in any upstaging of patients. We conclude that in patients with small cell lung cancer, functional imaging by SRS has no impact on clinical decision making.

Value of quantitative salivary gland scintigraphy in the early stage of Sjögren's syndrome.

The aim of this study was to test the impact of quantitative salivary gland scintigraphy in patients with suspected Sjögren's syndrome. Thirteen patients with suspected Sjögren's syndrome were investigated. During clinical work-up, three had severe and four had mild Sjögren's syndrome, while six were normal. Quantitative salivary gland scintigraphy was performed using a standardized method. The normal data-base consisted of 172 patients without any evidence of salivary gland malfunction. Visual and quantitative comparisons of the patients' scintigrams were made. In the patients with severe Sjögren's syndrome, uptake was 0.10 +/- 0.04% and 0.09 +/- 0.03% in the parotid and submandibular glands respectively, confirming the visual diagnosis. In the patients without Sjögren's syndrome, concordance between the visual and quantitative evaluations could also be shown. In contrast, among the patients with mild Sjögren's syndrome, uptake was diminished (P < 0.05), amounting to 0.21 +/- 0.05% and 0.16 +/- 0.02% in the parotid and submandibular glands respectively, while visual analysis indicated normal parenchymatous function. In conclusion, quantitative salivary gland scintigraphy is essential for the reliable detection of parenchymatous malfunction at an early stage of Sjögren's syndrome, which may be missed by visual analysis alone.