Intra-arterial peptide-receptor radionuclide therapy for neuro-endocrine tumour liver metastases: an in-patient randomised controlled trial (LUTIA)

PURPOSE

Peptide receptor radionuclide therapy (PRRT) using [177Lu]Lu-DOTATATE has been shown to effectively prolong progression free survival in grade 1-2 gastroenteropancreatic neuroendocrine tumours (GEP-NET), but is less efficacious in patients with extensive liver metastases. The aim was to investigate whether tumour uptake in liver metastases can be enhanced by intra-arterial administration of [177Lu]Lu-DOTATATE into the hepatic artery, in order to improve tumour response without increasing toxicity.

METHODS

Twenty-seven patients with grade 1-2 GEP-NET, and bi-lobar liver metastases were randomized to receive intra-arterial PRRT in the left or right liver lobe for four consecutive cycles. The contralateral liver lobe and extrahepatic disease were treated via a "second-pass" effect and the contralateral lobe was used as the control lobe. Up to three metastases (> 3 cm) per liver lobe were identified as target lesions at baseline on contrast-enhanced CT. The primary endpoint was the tumour-to-non-tumour (T/N) uptake ratio on the 24 h post-treatment [177Lu]Lu-SPECT/CT after the first cycle. This was calculated for each target lesion in both lobes using the mean uptake. T/N ratios in both lobes were compared using paired-samples t-test.

FINDINGS

After the first cycle, a non-significant difference in T/N uptake ratio was observed: T/NIA = 17·4 vs. T/Ncontrol = 16·2 (p = 0·299). The mean increase in T/N was 17% (1·17; 95% CI [1·00; 1·37]). Of all patients, 67% (18/27) showed any increase in T/N ratio after the first cycle.

CONCLUSION

Intra-arterial [177Lu]Lu-DOTATATE is safe, but does not lead to a clinically significant increase in tumour uptake.

A physiologically based pharmacokinetic (PBPK) model to describe organ distribution of 68Ga-DOTATATE in patients without neuroendocrine tumors

Background

Physiologically based pharmacokinetic (PBPK) models combine drug-specific information with prior knowledge on the physiology and biology at the organism level. Whole-body PBPK models contain an explicit representation of the organs and tissue and are a tool to predict pharmacokinetic behavior of drugs. The aim of this study was to develop a PBPK model to describe organ distribution of ⁶⁸Ga-DOTATATE in a population of patients without detectable neuroendocrine tumors (NETs).

Methods

Clinical ⁶⁸Ga-DOTATATE PET/CT data from 41 patients without any detectable somatostatin receptor (SSTR) overexpressing tumors were included. Scans were performed at 45 min (range 30–60 min) after intravenous bolus injection of ⁶⁸Ga-DOTATATE. Organ (spleen, liver, thyroid) and blood activity levels were derived from PET scans, and corresponding DOTATATE concentrations were calculated. A whole-body PBPK model was developed, including an internalization reaction, receptor recycling, enzymatic reaction for intracellular degradation and renal clearance. SSTR2 expression was added for several organs. Input parameters were fixed or estimated using a built-in Monte Carlo algorithm for parameter identification.

Results

⁶⁸Ga-DOTATATE was administered with a median peptide amount of 12.3 µg (range 8.05–16.9 µg) labeled with 92.7 MBq (range 43.4–129.9 MBq). SSTR2 amounts for spleen, liver and thyroid were estimated at 4.40, 7.80 and 0.0108 nmol, respectively. Variability in observed organ concentrations was best described by variability in SSTR2 expression and differences in administered peptide amounts.

Conclusions

To conclude, biodistribution of ⁶⁸Ga-DOTATATE was described with a whole-body PBPK model, where tissue distribution was mainly determined by variability in SSTR2 organ expression and differences in administered peptide amounts.

The development and validation of a high performance liquid chromatography method to determine the radiochemical purity of [177Lu]Lu-HA-DOTA-TATE in pharmaceutical preparations

Lutetium-177 [¹⁷⁷Lu] tetra-azacyclododecanetetra-acetic acid [DOTA]-(Tyr3)-octreotate [TATE] ([¹⁷⁷Lu]Lu-DOTA-TATE) is a radiopeptide used for peptide receptor radionuclide therapy in patients with neuroendocrine tumours (NETs). This radiopeptide is made by labelling the ligand octreotate with Lutetium-177 using the linker DOTA. After labelling, and before clinical application quality control of the radiopeptide is needed and the radiochemical purity is assessed. Acceptance limits for radiochemical purity should be within 90-110% of the label claim for radiopharmaceuticals for diagnostic use and within 95-105% of the label claim for radiopharmaceuticals for therapeutic use. Moreover, the amount of unlabelled [¹⁷⁷Lu]LuCl₃ cannot exceed 2% of the radioactive dose. Since no monograph is available for [¹⁷⁷Lu]Lu-DOTA-TATE in the European Pharmacopeia (Ph Eur), this article describes the development and validation of a high-performance liquid chromatography (HPLC) method with ultraviolet (UV) detection and radiodetection. A Waters Acquity Arc UHPLC system equipped with a Waters 2998 photodiode array (PDA) detector was used coupled to a Berthold Lb 514 Flowstar detector equipped with a BGO-X gamma measuring cell. A reversed phase Symmetry Shield C18 column (4.6 mm × 250 mm, 5 µm) was used for chromatographic separation. A flow of 1.5 mL/min was maintained during analysis, using 0.1% TFA in water as mobile phase A and 0.1% TFA in ACN as mobile phase B. The retention time was around 1.7 min and 13.5 min for [¹⁷⁷Lu]LuCl₃ and [¹⁷⁷Lu]Lu-HA-DOTA-TATE, respectively. Stock solutions of [¹⁷⁷Lu]LuCl₃ were made by serial dilution and were injected to test for linearity, accuracy and precision, carry over and signal-to-noise ratio. A [¹⁷⁷Lu]Lu-HA-DOTA-TATE sample was prepared and injected to determine the carry over. The results showed that the method is linear over a range of 0.300-130 MBq/mL, which covers the range for clinical samples, provided that the clinical sample is diluted ten times before analysis. The LLOQ can be measured accurately even after dilution, with a signal-to-noise ratio of at least 5. In short, the method is accurate, precise and sensitive and can be implemented as part of the quality control of [¹⁷⁷Lu]Lu-HA-DOTA-TATE.

Early differences in dynamic uptake of 68Ga-PSMA-11 in primary prostate cancer: A test-retest study

INTRODUCTION

Dynamic PET/CT allows visualization of pharmacokinetics over the time, in contrast to static whole body PET/CT. The objective of this study was to assess 68Ga-PSMA-11 uptake in pathological lesions and benign tissue, within 30 minutes after injection in primary prostate cancer (PCa) patients in test-retest setting.

MATERIALS AND METHODS

Five patients, with biopsy proven PCa, were scanned dynamically in list mode for 30 minutes on a digital PET/CT-scanner directly after an intravenous bolus injection of 100 MBq 68Ga-PSMA-11. Approximately 45 minutes after injection a static whole body scan was acquired, followed by a one bed position scan of the pelvic region. The scans were repeated approximately four weeks later, without any intervention in between. Semi-quantitative assessment was performed using regions-of-interest in the prostate tumor, bladder, gluteal muscle and iliac artery. Time-activity curves were extracted from the counts in these regions and the intra-patient variability between both scans was assessed.

RESULTS

The uptake of the iliac artery and gluteal muscle reached a plateau after 5 and 3 minutes, respectively. The population fell apart in two groups with respect to tumor uptake: in some patients the tumor uptake reached a plateau after 5 minutes, whereas in other patients the uptake kept increasing, which correlated with larger tumor volumes on PET/CT scan. Median intra-patient variation between both scans was 12.2% for artery, 9.7% for tumor, 32.7% for the bladder and 14.1% for the gluteal muscle.

CONCLUSION

Dynamic 68Ga-PSMA-11 PET/CT scans, with a time interval of four weeks, are reproducible with a 10% variation in uptake in the primary prostate tumor. An uptake plateau was reached for the iliac artery and gluteal muscle within 5 minutes post-injection. A larger tumor volume seems to be related to continued tumor uptake. This information might be relevant for both response monitoring and PSMA-based radionuclide therapies.

Performance evaluation of Cerenkov luminescence imaging: a comparison of 68Ga with 18F

BACKGROUND

Cerenkov Luminescence Imaging (CLI) is an emerging technology for intraoperative margin assessment. Previous research only evaluated radionuclide 18-Fluorine (¹⁸F); however, for future applications in prostate cancer, 68-Gallium (⁶⁸Ga) seems more suitable, given its higher positron energy. Theoretical calculations predict that ⁶⁸Ga should offer a higher signal-to-noise ratio than ¹⁸F; this is the first experimental confirmation. The aim of this study is to investigate the technical performance of CLI by comparing ⁶⁸Ga to ¹⁸F.

RESULTS

The linearity of the system, detection limit, spatial resolution, and uniformity were determined with the LightPath imaging system. All experiments were conducted with clinically relevant activity levels in vitro, using dedicated phantoms. For both radionuclides, a linear relationship between the activity concentration and detected light yield was observed (R² = 0.99). ⁶⁸Ga showed approximately 22 times more detectable Cerenkov signal compared to ¹⁸F. The detectable activity concentration after a 120 s exposure time and 2 × 2 binning of ¹⁸F was 23.7 kBq/mL and 1.2 kBq/mL for ⁶⁸Ga. The spatial resolution was 1.31 mm for ¹⁸F and 1.40 mm for ⁶⁸Ga. The coefficient of variance of the uniformity phantom was 0.07 for the central field of view.

CONCLUSION

⁶⁸Ga was superior over ¹⁸F in terms of light yield and minimal detection limit. However, as could be expected, the resolution was 0.1 mm less for ⁶⁸Ga. Given the clinical constraints of an acquisition time less than 120 s and a spatial resolution < 2 mm, CLI for intraoperative margin assessment using ⁶⁸Ga could be feasible.

The success of 131I ablation in thyroid cancer patients is significantly reduced after a diagnostic activity of 40 MBq 131I

Objective: Dosimetry studies have shown that activities of 131I as small as 10-20 MBq may cause a stunning effect. A result of this stunning effect may be a lower success rate of the ablative 131I therapy for differentiated thyroid carcinoma (DTC). The aim of this study was to determine whether pre-therapeutic uptake measurement with 40 MBq 131I causes a lower success rate of ablation. Design: retrospective chart review study. Patients, methods: In two hospitals the ablation protocols differed in one respect only: in the one hospital no diagnostic 131I was applied before ablation (group 1, n = 48), whereas in the other hospital a 24-h uptake-measurement with 40 MBq 131I was performed (group 2, n = 51). Included were all DTC patients without distant metastases who had undergone 131I ablation between July 2002 and December 2005, and who had returned for 131I follow-up. Successful ablation was defined as absence of pathological 131I uptake on diagnostic whole-body scintigraphy and undetectable thyroglobulin-levels under TSH stimulation. Results: Overall, ablation was successful in 31/48 patients (65%) in group 1 and in 17/51 patients (33%) in group 2 (p=0.002). Multivariate analysis showed that pre-therapeutic uptake measurement using 40 MBq 131I was an independant determinant for success of ablation (p = 0.002). Conclusions: After applying a diagnostic activity of 40 MBq 131I before ablation, the success rate of ablation is severely reduced. Consequently, the routine application of 131I for diagnostic scintigraphy or uptake measurement prior to 131I ablation is best avoided.

PET/CT with 18F-FDG predicts short-term outcome in stage II/III breast cancer patients upstaged to N2/3 nodal disease

INTRODUCTION

¹⁸F-FDG PET/CT has high positive predictive value for the detection of avid lymph node metastases in breast cancer patients. We analysed the effect of upstaging lymph nodes by PET/CT on short-term outcome in stage II/III breast cancer patients.

PATIENTS AND METHODS

A total of 278 stage II/III primary breast cancer patients (mean age 48.9 years, range 19-75 years) were re-staged with ¹⁸F-FDG PET/CT before start of pre-operative systemic treatment (PST). Patients were divided in three groups based on risk for local recurrence: a low - (T2N0), intermediate - (T0-2N1 and T3N0) and a high-risk group (T0-3N2-3, T3N1 and T4). Within these groups we looked at local recurrence-free survival (LRFS), recurrence-free survival (RFS) and overall survival (OS) within the first 3 years of follow-up.

RESULTS

With a median follow-up (FU) of 50 months the RFS, LRFS and OS were 87%, 88% and 92% respectively for the whole group. PET/CT upstaged 43 patients from the low- and intermediate risk group to the high-risk group, based on detection of ≥4 avid axillary nodes or occult N2/3-disease. Patients upstaged with PET/CT had more events for all three analyses compared to the original risk groups, which resulted in a significantly worse RFS (69.8%; p = 0.03) a nearly significantly worse LRFS (p = 0.052) and no effect in OS (p = 0.433).

DISCUSSION

Additional PET/CT staging allows breast cancer patients to be treated according to the true stage, still stage II/III breast cancer patients upstaged to N2/3 by PET/CT have worse short-term outcome, despite adjustment of treatment, than patients staged high-risk with conventional imaging.

The hidden sentinel node in breast cancer: Reevaluating the role of SPECT/CT and tracer reinjection

INTRODUCTION

Lymphoscintigraphy with planar imaging is considered a helpful tool to depict lymph node drainage in patients with invasive breast cancer. Single Photon Emission Computed Tomography with integrated CT (SPECT/CT) is usually performed to detect sentinel nodes (SN)s in breast cancer patients showing non-visualisation on lymphoscintigraphy. Incorporation of new SN indications (recurrent surgery, previous radiotherapy, or neo-adjuvant chemotherapy) has led to an increase of non-visualisation rates. The present study evaluates the contribution of SPECT/CT and tracer reinjection for SN-visualisation in breast cancer patients without drainage on lymphoscintigraphy.

METHODS

Between 1st of July 2008 and 6th of November 2014 in total 1968 patients underwent a SN breast procedure, using intra-tumoural tracer administration. SPECT/CT was performed in 284 breast cancer patients with non-visualisation of SNs on lymphoscintigraphy. If SN non-visualisation persisted, a second radiotracer injection with repeated imaging was performed when logistics allowed this. Univariate analysis was applied to evaluate SPECT/CT visualisation rates in specific subgroups.

RESULTS

The SPECT/CT visualisation rate was 23.2% (66/284). Univariate analysis revealed no significant subgroups influencing SPECT/CT visualisation. In patients receiving reinjection after persistent SPECT/CT non-visualisation the SN-visualisation rate reached 62.1% (36/58). Intraoperatively, the SN-identification rate using a gamma probe and blue dye was 87.9% (175/199) and 32.9% (28/85) for, respectively, primary and recurrent surgery after non-visualisation on lymphoscintigraphy.

CONCLUSION

In this evaluation including new breast cancer SN indications, SPECT/CT scored lower than reinjection to visualise SNs in patients with non-visualisation on lymphoscintigraphy. Consequently, our institutional protocol has been readjusted.

High prevalence of vertebral fractures despite normal bone mineral density in patients with long-term controlled acromegaly

OBJECTIVE

To establish the prevalence of osteoporosis, vertebral fractures (VFs), and non-VFs in acromegaly patients with long-term controlled disease and factors potentially influencing fracture risk.

DESIGN

Case-control study. Patients and measurements Eighty-nine patients (46% male, mean age: 58 years) were included. We studied VFs and non-VFs, bone mineral density (BMD), and markers of bone turnover. In 48 patients, BMD assessment was also obtained 7 years prior to the current study. To compare VF prevalence, data from a sample of the Dutch population (n=3469) were used.

RESULTS

VF prevalence was 59% (men 64% and women 54%), significantly increased when compared with controls (odds ratio up to 6.5), and independent of the duration of disease control, BMD, markers of bone turnover, and acromegalic disease characteristics. Mean number of VFs per patient was 3.4±0.3 (range 1-8). There was no relationship between the number and severity of fractures, parameters of bone turnover, and follow-up BMD measurements. BMD did not change during prolongation of follow-up by 7 years of controlled acromegaly.

CONCLUSION

There is a very high prevalence of VFs in acromegaly patients with long-term controlled disease, independently of BMD. In view of the significant morbidity and mortality associated with VFs in general and the inability of BMD to predict fracture risk in acromegalic patients, we propose to include VF assessment, for example by lateral conventional radiographs of the spine in the screening of patients with acromegaly, both at diagnosis and during follow-up after establishment of disease control.

Transient ischemic dilatation ratio derived from myocardial perfusion scintigraphy: What are we looking at?

BACKGROUND

Elevated transient ischemic dilatation (TID) ratio during myocardial perfusion imaging (MPI) is described as a marker of severe CAD, even in acquisitions with normal perfusion. This was initiated to explore the effects of stressor type on the TID. Additionally the relation between the TID and other functional parameters, such as end diastolic volume (EDV), end systolic volume (ESV), and left ventricle ejection fraction (LVEF), heart rate (HR), and severity of ischemia, was evaluated.

METHOD

A total of 299 consecutive patients referred for a 2-day stress/rest MPI protocol were included. Patients were stressed with either adenosine (n = 164) or exercise (n = 135). MPI data were analyzed with an automated software tool to determine TID, EDV, ESV, LVEF, SSS, and SDS. The SDS was used to quantify the degree of ischemia, with a SDS > or = 3 considered ischemic.

RESULTS

Comparison of the adenosine and exercise stressed population revealed significant differences, especially in parameters derived from the poststress acquisition. Within the exercise stressed population, TID was proportional with the SDS (R(2) = .12); whereas the adenosine population did not show such a relation (R(2) = .001). Difference in HR between rest and poststress acquisitions showed high levels of linear regression with TID values of both the adenosine (R(2) = .41) and exercise (R(2) = .29) stressed population.

CONCLUSION

In an exercise stressed population, TID is determined by both the degree of ischemia and the heart-rate difference between the two acquisition moments. TID within the adenosine population was found to be highly proportional with the HR, rather than with the degree of ischemia.

Clinical outcomes after estimated versus calculated activity of radioiodine for the treatment of hyperthyroidism: systematic review and meta-analysis

BACKGROUND

Despite the long experience with radioiodine for hyperthyroidism, controversy remains regarding the optimal method to determine the activity that is required to achieve long-term euthyroidism.

OBJECTIVES

To compare the effect of estimated versus calculated activity of radioiodine in hyperthyroidism. Design Systematic review and meta-analysis.

METHODS

We searched the databases Medline, EMBASE, Web of Science, and Cochrane Library for randomized and nonrandomized studies, comparing the effect of activity estimation methods with dosimetry for hyperthyroidism. The main outcome measure was the frequency of treatment success, defined as persistent euthyroidism after radioiodine treatment at the end of follow-up in the dose estimated and calculated dosimetry group. Furthermore, we assessed the cure rates of hyperthyroidism.

RESULTS

Three randomized and five nonrandomized studies, comparing the effect of estimated versus calculated activity of radioiodine on clinical outcomes for the treatment of hyperthyroidism, were included. The weighted mean relative frequency of successful treatment outcome (euthyroidism) was 1.03 (95% confidence interval (CI) 0.91-1.16) for estimated versus calculated activity; the weighted mean relative frequency of cure of hyperthyroidism (eu- or hypothyroidism) was 1.03 (95% CI 0.96-1.10). Subgroup analysis showed a relative frequency of euthyroidism of 1.03 (95% CI 0.84-1.26) for Graves' disease and of 1.05 (95% CI 0.91-1.19) for toxic multinodular goiter.

CONCLUSION

The two main methods used to determine the activity in the treatment of hyperthyroidism with radioiodine, estimated and calculated, resulted in an equally successful treatment outcome. However, the heterogeneity of the included studies is a strong limitation that prevents a definitive conclusion from this meta-analysis.

[Intramyocardial injection of autologous bone-marrow stem cells in a 74-year-old man with untreatable angina pectoris and demonstrated myocardial ischaemia]

For a 74-year-old man with angina pectoris and demonstrated myocardial ischaemia, optimal medical treatment was insufficient. He was ineligible for coronary revascularization. To improve myocardial perfusion, autologous bone-marrow stem cells were injected into the ischaemic myocardium. During the months following the injection, the frequency of angina attacks decreased and myocardial perfusion and cardiac function improved.

Lithium as adjuvant to radioiodine therapy in differentiated thyroid carcinoma: clinical and in vitro studies

OBJECTIVE

Lithium has been reported to increase radioactive iodine (RaI) doses in benign thyroid disease and in differentiated thyroid carcinoma (DTC). It is not known whether lithium influences the outcome of RaI therapy in DTC. We therefore studied the clinical effects of RaI without and with lithium carbonate in patients with proven metastatic DTC. Controversy also exists on the mechanism by which lithium increases RaI dose in DTC. We performed an in vitro study specifically aimed at examining the effects of lithium on the sodium iodide symporter (NIS).

DESIGN

In a clinical study, 12 patients were selected with metastases of DTC who had received previous RaI therapy without lithium (control) that had not influenced tumour progression, despite RaI accumulation in metastases. The patients received 1200 mg lithium carbonate/day followed by 6000 MBq RaI. Outcome parameters were RaI uptake, serum thyroglobulin (Tg) levels and radiological dimensions of metastases compared between RaI with lithium and control. In an in vitro study, iodide uptake was studied in the benign rat thyroid cell line FRTL-5, in the polarized non-thyroid MDCK cell line, stably transfected with human sodium iodide symporter (hNIS) to study the effects of lithium on NIS in a non-thyroid background, and the human follicular thyroid carcinoma cell line FTC133-hNIS to study lithium effects in a background of DTC. Lithium chloride (LiCl) was added in concentrations up to 2 mM for 0-48 h. Both steady-state iodide uptake (30 min) and initial rate (2 min) were studied using a specific activity of 100 mCi/mmol I, the latter experiment to determine lithium effects on substrate dependency. Iodide efflux studies were performed as well.

RESULTS

Despite an increased uptake of RaI in seven patients, no beneficial effect of RaI with lithium was observed on the clinical course as assessed by serum Tg measurements and radiographically. In the in vitro studies, no effects of LiCl on iodide uptake or efflux were observed.

CONCLUSIONS

The addition of lithium to RaI did not have any beneficial effects on the clinical course in 12 patients with metastatic DTC. No beneficial effects of lithium on iodide uptake were observed in vitro. Therefore, the clinical value of lithium in DTC remains subject to debate.

The value of FDG-PET in the follow-up of differentiated thyroid cancer: a review of the literature

Well differentiated (follicular and papillary) thyroid cancer (DTC) is characterized by rare occurrence and a good prognosis. However, up to 20% of patients with DTC develop locoregional recurrences, whereas even 8% of patients with such recurrences will eventually die from disease. In some of these patients it is related to incomplete initial treatment, whereas in others it indicates the presence of an aggressive tumor. In this latter case, dedifferentiation may occur with negative I-131 whole body scintigraphy (WBS) results and unreliable Tg measurements. In patients with thyroid cancer metastases that lost the capability of I-131 uptake, other imaging techniques are required to depict the non-functioning metastases, irrespective of the Tg-levels and irrespective of the site of recurrent disease. In this respect, some reports have discussed the value of ultrasonography of the head and neck region with good results for the detection of locoregional disease. We have assessed the role of FDG-PET in patients with I-131 negative WBS and its relation with Tg values and TSH-stimulation based on data that have appeared in the literature. In this review article, a discussion is given on the results published so far.

Increased prevalence of catecholamine excess and phaeochromocytomas in a well-defined Dutch population with SDHD-linked head and neck paragangliomas

OBJECTIVE

The aim of this study was to identify the prevalence of catecholamine excess and phaeochromocytomas in a well-defined population of people with hereditary head and neck paragangliomas.

METHODS

We studied in a prospective follow-up protocol all consecutive patients referred to the Department of Endocrinology, Leiden University Medical Center, Leiden, The Netherlands with documented head and neck paragangliomas and either a positive family history for paragangliomas or a proven SDHD gene mutation. Initial analysis included medical history, physical examination and the measurement of excretion of catecholamines in two 24-h urine collections. In the case of documented catecholamine excess iodinated meta-iodobenzylguanidine (123I-MIBG) scintigraphy and magnetic resonance imaging were done.

RESULTS

Between 1988 and 2003, 40 consecutive patients (20 male and 20 female) with documented head and neck paragangliomas were screened. Biochemical screening revealed urinary catecholamine excess in 15 patients (37.5%). In nine of these 15 patients a lesion was found by 123I-MIBG scintigraphy. Exact localization by magnetic resonance imaging revealed phaeochromocytomas in seven of the 15 patients. One of the nine patients had an extra-adrenal paraganglioma. Histopathological examination in a subset of tumors displayed loss of heterozygosity of the wild-type SDHD allele in all cases.

CONCLUSIONS

The prevalence of catecholamine excess (37.5%) and phaeochromocytomas (20.0%) is high in patients with familial head and neck paragangliomas. Therefore, patients with hereditary head and neck paragangliomas require lifelong follow up by biochemical testing for catecholamine excess.

Intractable congenital chylous ascites

A male newborn presented with congenital chylous ascites, the treatment of which is difficult and complicated due to persistent loss of chyle. The primary therapeutic goal is to reduce the lymph flow and to allow the leakage to heal naturally. Usually, conservative management--enteric rest with total parental feeding or an enteral diet with medium-chain triglycerides--can achieve this. A new treatment option is the use of octeotride, a somatostatin analogue. Both therapies failed in our patient, and surgical ligation of the leaking lymphatic duct was successful.

CONCLUSION

The success of the surgical treatment depends on localizing the leaking lymphatic duct. Lymphatic imaging with lymphoscintigraphy and pre-operative administration of lipophilic dye can assist the surgeon.

Feasibility study on the retention of superporous hydrogel composite polymer in the intestinal tract of man using scintigraphy

In recent years, many complex oral drug delivery systems have been developed using various polymers in order to achieve better drug targeting and drug absorption in the intestinal tract. Superporous hydrogel (SPH) and SPH composite (SPHC)-based drug delivery systems were also developed for the targeted delivery of peptide drugs into the intestinal tract. In the present study, the retention time of SPHC polymer is studied in man using the scintigraphy technique. To that purpose, SPHC polymers were radiolabelled with Tc-99m and administered orally in an enteric-coated gelatin capsule. The location of the radiolabelled polymer was monitored in five healthy volunteers while the subjects were sitting in front of a large field of view gamma camera. The results showed that enteric-coated gelatin capsules remained in the stomach for 75 to 150 min after oral administration to fasted volunteers and that the SPHC polymers thereafter attached to the upper part of the small intestine for at least 45 to 60 min due to their mechanical fixation properties. No discomfort was observed in any of the volunteers after oral administration of these polymers, which indicates that they are safe to be applied for oral drug delivery systems in man.

Personal dosimetry of the staff during treatment of neuroendocrine tumours with a high dose of Indium-111 Octreotide

BACKGROUND

Therapeutic doses with Indium-111 (In-111)-DTPA-Octreotide are currently used in patients with somatostatin receptor positive tumours. It may result in tumour regression in some patients and this effect is ascribed to cell and receptor specific cytotoxicity by Auger or conversion electrons. Personnel being involved in this treatment may receive high radiation doses due to the emission of 173 keV and 247 keV photons. The aim of the present study was to assess the radiation dose to the personnel at different time intervals during treatment with Indium-111 Octreotide.

METHODS

Five consecutive patients suffering from a neuroendocrine tumour were included in this dosimetry study. In total, 18 treatments with Indium-111 Octreotide have been given with a mean dose of 8000 MBq every three weeks. Three dosimeters (whole body, left and right hand) and a dose rate monitor were used to register doses and dose rates during labelling, administration and in-patient follow-up and whole body scintigraphy. These procedures were performed by a pharmacist, a nuclear physician and a technologist, respectively.

RESULTS

The whole body dose received during the labelling procedure was 5 microSv. The mean total exposure time during administration, whole body scintigraphy and clinical follow-up was 47 minutes revealing a mean whole body dose of 45 microSv. The mean radiation dose to the hands was 60 microSv per treatment.

CONCLUSIONS

The radiation risk to staff members and technologists seems to be very low during in-patient treatments with high dose Indium-111 Octreotide. According to the safety regulations no special radiation protection measures or personal dosimetry is required.

A reassessment of bone scintigraphy and commonly tested pretreatment biochemical parameters in newly diagnosed osteosarcoma

PURPOSE

In patients with an osteosarcoma, the prognosis is still poor. The aim of the present study was to investigate whether routinely tested biochemical parameters or additional parameters on bone scintigraphy could be identified which can select prognostic subgroups at the time of diagnosis.

METHODS

A retrospective study was performed in 115 consecutive patients (70 male, 45 female) (mean age: 25.6 years; range: 3.50-78.0 years) who were referred for bone scintigraphy prior to treatment from March 1986 to September 2000 because of a newly diagnosed osteosarcoma. All bone scans were reassessed for the intensity and pattern of uptake and a bone-scan index. All pre-treatment general, histological, biochemical, and scintigraphic data were correlated with clinical outcome during follow-up.

RESULTS

During follow-up 54 patients died. Tumour volume and GGT showed significance as independent variables for metastases. Patients with metastases demonstrated a significantly lower survival rate (23% 5-year survival) than patients without metastases (98% 5-year survival). Tumours of the humerus and femur had a significantly lower survival rate. With respect to significant biochemical parameters (ALP, GGT, ASAT), it was not possible to determine a cut-off value that could be used to differentiate between high- and low-risk patients. Additional parameters assessed on bone scintigraphy were not important for prognostic stratification.

CONCLUSION

The strongest predictor of survival in osteosarcoma is the presence or absence of metastasis. Some biochemical parameters have prognostic value, but they cannot be used for the unequivocal identification of subgroups. Additional scintigraphic parameters are irrelevant for prognostic stratification.

Circulating tumor markers and nuclear medicine imaging modalities: breast, prostate and ovarian cancer

Clinical oncologists have always shown great interest in circulating tumor markers. There are several markers that in the clinical routine are a signal of particular tumor types; some of them are strictly tissue-specific such as prostatic specific antigen (PSA) for prostatic cancer, AFP and HCG for germ cell tumors of the testis and ovary, others such as CA 15.3, CA125, CEA or cytokeratins are less specific since their elevations can be found in different varieties of cancers even if they are preferentially associated to a certain tumor type, thus are considered markers for breast, ovarian cancer and colon adenocarcinoma. The most useful clinical applications of these parameters is their determination during the follow-up of the treated patients, in order to detect the tumor recurrence early, and also to evaluate the evolution of the disease by monitoring the treatment responses. During follow-up, increasing levels of tumor markers can be observed even several months before the clinical demonstration of cancer recurrence. The association of tumor marker tests with imaging modalities can lead to several advantages: the first is to confirm the diagnosis of relapses, possibly before the appearence of the related clinical symptoms due to tumor growth; the second is to localize the sites of lesions, while tumor markers provide only a general indication of the existence of metastases; the third is to make possible a correct whole body restaging. In the assessment of cancer response tumor markers are often very reliable and their changes are faster than the morphological ones. Among all the imaging modalities, nuclear medicine plays an important role in detecting recurrences and metastatic localizations as it is able to investigate functional rather than morphological aspects of tumors, and provide different information in comparison to morphologic imaging. In addition, the scintigraphic techniques offer the possibility to evaluate treatment responses, confirming or not the information from biochemical changes. This review aims to show some examples (breast, prostate and ovarian cancer) in which the combination of nuclear medicine imaging modalities and tumor marker tests is proposed for clinical practice. The advantages and some critical aspects are discussed on the basis of the clinical findings and the most important clinical indications are described.