Instability of the first metatarsal-cuneiform joint: diagnosis and discussion of an independent pain generator in the foot.

BACKGROUND: First metatarsocuneiform (MC) instability is recognized as a pathologic contributor to hallux valgus. There are no studies identifying the first MC joint as an independent pain generator in the foot that may require surgical arthrodesis for its management. MATERIALS AND METHODS: The authors reviewed the records of all patients with this newly described pathology in the first MC joint. There were 61 patients with 85 feet who underwent a fluoroscopically guided local anesthetic injection into the first metatarsocuneiform joint to assess pain relief. Patient's complaints, physical exam findings, treatment decisions, patient characteristics, and radiographic findings were evaluated. RESULTS: Seventy-nine percent of patients (67/85) injected had relief of their symptoms. Eight or these 67 patients were eventually treated with first MC arthrodesis with complete relief of symptoms. The average time from onset of symptoms to presentation was 21 (range, 1 to 72) months. Eighty-five percent of feet (72/85) had multiple previous diagnoses. Radiographic plantar widening of the first M-C joint on weightbearing views was inconsistent with pathology. CONCLUSION: The first MC joint is an independent pain generator in the foot that can have variable presentations. Radiographic data can often be helpful, but clinical exam findings are paramount in the diagnosis. Fluoroscopically-guided long acting local anesthetic injections of this joint are helpful in the diagnosis, especially in the patient with multiple possible pain generators in the foot and ankle. Failure to recognize the first MC joint as a source of pain may lead to delay in treatment, misdiagnosis, and mistreatment of foot pathology.

Comparison of MRI and local anesthetic tendon sheath injection in the diagnosis of posterior tibial tendon tenosynovitis.

BACKGROUND: The modalities currently available to clinicians to confirm the clinical suspicion of posterior tibial tendinitis include MRI, CT, sonography, tenography, and local anesthetic tendon sheath injections. There are no reports in the literature comparing local anesthetic tendon sheath injection to MRI as tools for diagnosing posterior tibial tenosynovitis. METHODS: The authors reviewed the records of all patients with stage 1 posterior tibial tendon dysfunction between the dates of September 1, 2001, to November 21, 2004. Fifteen patients (17 ankles) had a local anesthetic injection into the posterior tibial tendon sheath and MRI for clinically suspected tenosynovitis of the posterior tibial tendon. RESULTS: Seventeen (100%) of 17 ankles had complete relief of symptoms after the local anesthetic tendon sheath injections. Fifteen (88%) of 17 ankles had abnormally increased fluid signal within the posterior tibial tendon sheath seen on MRI. Two of two ankles (100%), after having negative MRI findings, had complete relief with a local anesthetic tendon sheath injection. In addition, conservative treatment failed in these two patients, and they subsequently had tenosynovectomy with gross confirmation at surgery of inflammatory changes within the tendon sheath. These two patients had complete symptom relief after tenosynovectomy. CONCLUSIONS: Local tendon sheath injections and MRI are both reliable diagnostic tools. Injection of the posterior tibial tendon is an accurate, safe, and sensitive modality useful in patients in whom MRI studies are negative in the face of continued clinical suspicion.

Caffeine prevents protection in two human models of ischemic preconditioning.

OBJECTIVES: We studied whether caffeine impairs protection by ischemic preconditioning (IP) in humans. BACKGROUND: Ischemic preconditioning is critically dependent on adenosine receptor stimulation. We hypothesize that the adenosine receptor antagonist caffeine blocks the protective effect of IP. METHODS: In vivo ischemia-reperfusion injury was assessed in the thenar muscle by 99mTc-annexin A5 scintigraphy. Forty-two healthy volunteers performed forearm ischemic exercise. In 24 subjects, this was preceded by a stimulus for IP. In a randomized double-blinded design, the subjects received caffeine (4 mg/kg) or saline intravenously before the experiment. At reperfusion, 99mTc-annexin A5 was administered intravenously. Targeting of annexin was quantified by region-of-interest analysis, and expressed as percentage difference between experimental and contralateral hand. In vitro, we assessed recovery of contractile function of human atrial trabeculae, harvested during heart surgery, as functional end point of ischemia-reperfusion injury. Field-stimulated contraction was quantified at baseline and after simulated ischemia-reperfusion, in a paired approach with and without 5 min of IP, in the presence (n=13) or absence (n = 17) of caffeine (10 mg/l). RESULTS: Ischemic preconditioning reduced annexin targeting in the absence of caffeine (from 13 +/- 3% to 7 +/- 1% at 1 h, and from 19 +/- 2% to 9 +/- 3% at 4 h after reperfusion, p = 0.006), but not after caffeine administration (targeting 11 +/- 2% and 16 +/- 3% at 1 and 4 h). In vitro, IP improved post-ischemic functional recovery in the control group, but not in the caffeine group (8 +/- 3% vs. -8 +/- 5%, p=0.003). CONCLUSIONS: Caffeine abolishes IP in 2 human models at a dose equivalent to the drinking of 2 to 4 cups of coffee. (The Effect of Caffeine on Ischemic Preconditioning; http://clinicaltrials.gov/ct/show/NCT00184912?order=1; NCT00184912).

Absence of cardiotoxicity of the experimental cytotoxic drug cyclopentenyl cytosine (CPEC) in rats.

The experimental anticancer drug cyclopentenyl cytosine (CPEC) was associated with cardiotoxicity in a phase I study. The aim of the present study was twofold; first we investigated whether the observed effects could be reproduced in in-vitro and in-vivo rat models. Second, we intended to investigate the underlying mechanism of the possible cardiotoxicity of CPEC. Effects on frequency and contractility were studied on the isolated atria of 18 male Wistar rats. Atria were incubated with 0.1 mmol L(-1) (n = 6) or 1 mmol L(-1) (n = 6) CPEC for 1.5 h and compared with control atria (incubation with buffer solution, n = 6). The cardiac apoptosis-inducing potential was studied in-vivo on 66 rats by 99mTc-Annexin V scintigraphy, followed by postmortem determination of radioactivity in tissues, histological confirmation with the TUNEL assay (late-phase apoptosis), and immunohistochemical staining for cleaved caspase 3 and cytochrome C (early-phase apoptosis). Serum levels of the necrotic cardiomyopathy marker troponin T were also determined. No effect on heart frequency was found in the isolated atria after CPEC treatment. A trend towards a decrease of contraction force was observed. However, the differences were not statistically significant. 99mTc-Annexin V scintigraphy showed no increase in cardiac uptake ratio upon CPEC treatment in the in-vivo rat model, which was confirmed by determination of radioactivity in heart versus blood ratios. At each section a few individual isolated late apoptotic cells (< 5) could be identified by the TUNEL assay in the highest CPEC dose group (90 mg kg(-1)) but not in controls or in rats treated with 60 mg kg(-1) CPEC. Staining for the early apoptosis markers cleaved caspase 3 and cytochrome C did not reveal any significant differences between treated and control rats. Cardiac troponin T levels were not increased after CPEC treatment. CPEC does not affect heart frequency or contraction force in our cardiotoxicity models. Moreover, we did not find an indication of CPEC-induced apoptosis in heart tissue.

Annexin A5 scintigraphy of forearm as a novel in vivo model of skeletal muscle preconditioning in humans.

BACKGROUND: Nonlethal ischemia and reperfusion reduce ischemia-reperfusion-induced cell death, a phenomenon called ischemic preconditioning. In animal models, this potent endogenous protection is mimicked in vivo by administration of adenosine. In humans, exploitation of ischemic preconditioning is hindered by the lack of an appropriate in vivo model to study this phenomenon. To solve this problem, we aimed to set up an easy-to-use human in vivo model to study ischemic or pharmacological preconditioning. METHODS AND RESULTS: Healthy male volunteers performed unilateral ischemic handgrip. At reperfusion, we intravenously injected technetium-99m-labeled Annexin A5, a presumed marker of ischemic injury, and we imaged both forearms and hands simultaneously with a gamma camera. Region of interest analysis (counts per pixel) and subsequent calculation of the percentage difference in radioactivity between experimental and control hands (thenar muscle; mean+/-SE) revealed significant uptake to the ischemically exercised tissue (26+/-3% at 4 hours after reperfusion; P<0.05). This selective localization of Annexin A5 was reduced by ischemic preconditioning (10 minutes of ischemia plus reperfusion before ischemic exercise) or by infusion of adenosine into the brachial artery to 6+/-1% and 10+/-3%, respectively (P<0.05 versus ischemic exercise alone), resembling observations in animal models with infarct size as an end point. Appropriate control experiments supported our conclusion. CONCLUSIONS: Annexin A5 scintigraphy can be applied to test pharmacological or physiological interventions for their ability to prevent ischemia-reperfusion injury.

Intraobserver, interobserver, and day-to-day reproducibility of quantitative 99mTc-HYNIC annexin-V imaging in head and neck carcinoma.

RATIONALE: For clinical application, a sufficient reproducibility of 99mTc-HYNIC annexin-V quantitative uptake measurements must be demonstrated to allow a study of cell-death changes induced by chemotherapy over time and intersubject. Thus, the aim of this study was to estimate the intra-, inter-, and day-to-day reproducibility of quantitative 99mTc-HYNIC annexin-V tumor uptake values in patients suffering from head and neck carcinomas. METHODS: Thirteen (13) patients suffering from clinically suspected, histologically confirmed squamous head and neck carcinomas were prospectively included in the study. All patients were scheduled to undergo a spiral computed tomography scan and two 99mTc-HYNIC annexin-V scintigraphies within 3-5 days from each other, referred to as day 1 and day 2 of scintigraphy. The percentage of uptake of the injected dose of 99mTc-HYNIC annexin-V in tumor lesions on scintigrams divided by the tumor volume, as derived from CT, was determined twice within an interval of 2 weeks by observer 1 and once by observer 2 on day 1 of scintigraphy and once on day 2 of scintigraphy by observer 1. RESULTS: The mean of the difference for the intra-, inter-, and day-to-day measurements were -3.4%, 2.4%, and -6%, respectively. No systematic bias was observed for the mean of the differences for the intra-, inter-, and day-to-day measurements. The respective confidence intervals for the mean of the differences of intra-, inter-, and day-to-day variability were -8.2%-1.4%, -2.9%-7.8%, and -14.7%-2.7%. CONCLUSION: The reproducibility of quantitative 99mTc-HYNIC annexin-V tumor uptake measurements using a manual method appears to be acceptable for clinical use.

Annexin V imaging of acute doxorubicin cardiotoxicity (apoptosis) in rats.

UNLABELLED: Anthracyclines are widely used in chemotherapy regimens for several malignancies, with cardiotoxicity being the major limiting factor in high-dose schedules. Recently, it was reported that doxorubicin induces apoptosis in cardiac muscle cells in vivo and, as such, is expected to be involved in the genesis of doxorubicin-induced cardiomyopathy. The aim of this study was to validate an animal model for in vivo monitoring of doxorubicin cardiotoxicity by means of scintigraphic detection of apoptosis. METHODS: Three groups of 5 male Wistar rats each were treated for 3, 4, and 5 times with a weekly intraperitoneal injection of doxorubicin at 2.5 mg/kg. At 24 h before and 24 h after the final treatment, (99m)Tc-annexin pinhole scintigraphy was performed. A control group of 5 rats was scanned without doxorubicin treatment. A cardiac uptake ratio was calculated from planar scintigraphy results with the following formula: (mediastinum - fat)/fat. After scintigraphy, the rats were sacrificed, and the heart was processed for histologic analysis. RESULTS: Incremental general signs of illness were observed with increasing total cumulative doxorubicin dose. Rats treated for 3, 4, and 5 wk with doxorubicin showed significantly higher uptake ratios of, respectively, 4.0 +/- 0.52 (mean +/- SEM), 4.8 +/- 0.46, and 5.2 +/- 0.17 after the final treatment; the ratio for controls was 1.84 +/- 0.05 (P < 0.05). Histologic analysis confirmed cardiac stress in treated groups, with an increasing left ventricular atrial natriuretic factor messenger RNA expression level with increasing cumulative doxorubicin dose. Late apoptosis was confirmed by terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling in the rats treated for 5 wk. CONCLUSION: Acute doxorubicin-induced cardiomyopathy based on early apoptosis can be assessed and imaged with annexin V scintigraphy in rats. This finding makes it possible to use this animal model for repetitive noninvasive evaluation of cardioprotective regimens for anthracycline cardiotoxicity.

Apoptosis-detecting radioligands: current state of the art and future perspectives.

This review provides a critical and thorough overview of the radiopharmaceutical development and in vivo evaluation of all apoptosis-detecting radioligands that have emerged so far, along with their possible applications in nuclear medicine. The following SPECT and PET radioligands are discussed: all forms of halogenated Annexin V (i.e. (123)I-labelled, (124)I-labelled, (125)I-labelled, (18)F-labelled), (99m)Tc/(94m)Tc-labelled Annexin V derivatives using different chelators and co-ligands (i.e. BTAP, Hynic, iminothiolane, MAG(3), EDDA, EC, tricarbonyl, SDH) or direct (99m)Tc-labelling, (99m)Tc-labelled Annexin V mutants and (99m)Tc/(18)F-radiopeptide constructs (i.e. AFIM molecules), (111)In-DTPA-PEG-Annexin V, (11)C-Annexin V and (64)Cu-, (67)Ga- and (68)Ga-DOTA-Annexin V. In addition, the potential role and clinical relevance of anti-PS monoclonal antibodies and other alternative apoptosis markers are reviewed, including: anti-Annexin V monoclonal antibodies, radiolabelled caspase inhibitors and substrates and mitochondrial membrane permeability targeting radioligands. Nevertheless, major emphasis is placed on the group of Annexin V-based radioligands, in particular (99m)Tc-Hynic-Annexin V, since this molecule is by far the most extensively investigated and best-characterised apoptosis marker at present. Furthermore, the newly emerging imaging modalities for in vivo detection of programmed cell death, such as MRI, MRS, optical, bioluminescent and ultrasound imaging, are briefly described. Finally, some future perspectives are presented with the aim of promoting the development of potential new strategies in pursuit of the ideal cell death-detecting radioligand.

99mTc-HYNIC Annexin-V imaging of primary head and neck carcinoma.

In this study, the potential of 99mTc-HYNIC Annexin-V scintigraphy to visualize primary head and neck carcinoma was assessed and compared with computed tomography (CT) findings and histology. Eighteen patients suspected of having primary head and neck carcinoma underwent a spiral CT scan and 99mTc-HYNIC Annexin-V scintigraphy within 1 week of each other, followed by resection of the suspected lesion. Results obtained by CT and scintigraphy were compared vs. histopathology. The diagnosis was primary head and neck carcinoma in 18 patients, accompanied by lymph node involvement in seven patients. 99mTc-HYNIC Annexin-V uptake was identified in five patients on planar images and in 17 patients on tomographic images (single-photon emission computed tomography, SPECT), corresponding to the pathological regions identified by CT. In the remaining patient, CT and 99mTc-HYNIC Annexin-V scintigraphy were false negative. In 11 patients, SPECT and CT scan were concordant, identifying all primary lesions and two sites of lymph node involvement. In the six remaining patients, CT and SPECT accurately identified the primary lesion, but were discordant with regard to the existence of lymph node involvement. In five of six patients, SPECT failed to identify lymph node involvement, whereas CT scan did not. In the remaining patient, CT scan was false positive for lymph node involvement, whereas SPECT was not. In this series, 99mTc-HYNIC Annexin-V allowed for the visualization of all primary head and neck tumours identified by CT scan, but failed to identify most of the sites of lymph node involvement.

Relationship of 99mTc-HYNIC annexin V uptake to microvessel density, FasL and MMP-9 expression, and the number of tumour-infiltrating lymphocytes in head and neck carcinoma.

This study reports on the relationship between quantitative (99m)Tc-HYNIC radiolabelled annexin V tumour uptake measurements, Fas ligand (FasL) expression, matrix metalloproteinase-9 (MMP-9) expression, microvessel density (MVD) and the number of tumour-infiltrating lymphocytes in squamous cell carcinoma of the head and neck (SCCHN) patients. Twenty-eight patients (24 men and 4 women; mean age 59 years, range 43-83 years) suffering from a primary ( n, number of patients=22) or locally recurrent ( n=6) SCCHN were studied. All patients underwent a spiral CT scan, allowing estimation of lesion size in three dimensions, and (99m)Tc-HYNIC annexin V scintigraphy within 1 week of each other. Biopsies or resection of the suspected primary tumour or local recurrence for histopathological analysis were performed on all patients within a period of 10 days following (99m)Tc-HYNIC annexin V scintigraphy. The percentage uptake of the injected dose of (99m)Tc-HYNIC annexin V in visible tumour lesions on scintigrams divided by the tumour volume, derived from CT, was related to MVD and to histological score (HSCORE) values for MMP-9 and FasL expression as well as to the number of tumour-infiltrating lymphocytes (CD45 staining). Median percentage absolute tumour uptake of the injected dose/cm(3) tumour volume derived from tomographic images was 0.0001% (SD 0.0001%) at 5-6 h p.i. (range: 0.000007-0.0003%). Mean HSCORE for MMP-9 tumour staining was 2.1 (SD 0.84). Mean HSCORE for FasL tumour staining was 2.49 (SD 0.92). At the sites of tumour containing the highest number of vessels, the mean MVD was 20 vessels/field at the hot spot (range 1-73). The median number of tumour-infiltrating lymphocytes was 500 (range 100-5,000). The percentage absolute tumour uptake of the injected dose/cm(3) tumour volume derived from tomographic images correlated linearly with FasL HSCORES( r=0.47, P=0.02). No correlation was found between the percentage absolute tumour uptake of the injected dose/cm(3) tumour volume derived from tomographic images and MMP-9 HSCORES, MVD or the number of tumour-infiltrating lymphocytes. MVD correlated significantly with MMP-9 HSCORES ( r=0.44, P=0.03).

The imaging of apoptosis with the radiolabeled annexin V: optimal timing for clinical feasibility.

In recent years, the imaging of drug-induced apoptosis has become one of the centers of interest in experimental and clinical research. In particular, the accurate monitoring of chemosensitivity as well as the early prediction of chemoresistance in response to various pro-apoptotic interventions are critical requirements for the best management of oncology patients. The use of technetium [(99m)Tc]-labeled annexin V on animal and human models of cancers provides a proof of principle for the feasibility of a non-invasive, in vivo detection of an apoptotic signal and then for the early assessment of tumor response in the course of chemotherapy. Although promising, however, the initial clinical data point out on the technical limitations that are still to be resolved in terms of tumor-to-background ratio and optimal timing for the imaging of apoptosis. In the present review article, we report the results of animal studies aimed to the evaluation of apoptotic peaks following chemotherapy. In the light of these basic research works, we analyze the profiles of radiolabeled annexin V uptake over time as observed in clinical trials. We then discuss possible new imaging strategies designed to optimize the visualization of apoptotic changes within tumor tissues using the [(99m)Tc]-labeled annexin V. We also suggest longer lived forms of radiolabeled annexin V designed to better understand the temporal patterns of apoptotic tumor response, which in turn, may help to capture the best time-window for the imaging of cell death.

Targeting of apoptotic macrophages and experimental atheroma with radiolabeled annexin V: a technique with potential for noninvasive imaging of vulnerable plaque.

BACKGROUND: Apoptosis is common in advanced human atheroma and contributes to plaque instability. Because annexin V has a high affinity for exposed phosphatidylserine on apoptotic cells, radiolabeled annexin V may be used for noninvasive detection of apoptosis in atherosclerotic lesions. METHODS AND RESULTS: Atherosclerotic plaques were produced in 5 rabbits by deendothelialization of the infradiaphragmatic aorta followed by 12 weeks of cholesterol diet; 5 controls were studied without manipulation. Animals were injected with human recombinant annexin V labeled with technetium-99m before imaging. Aortas were explanted for ex vivo imaging, macroautoradiography, and histological characterization of plaque. Radiolabeled annexin V cleared rapidly from the circulation (T1/2, alpha 9 and beta 46 minutes). There was intense uptake of radiolabel within lesions by 2 hours; no uptake was seen in controls. The results were confirmed in the ex vivo imaging of the explanted aorta. Quantitative annexin uptake was 9.3-fold higher in lesion versus nonlesion areas; the lesion-to-blood ratio was 3.0+/-0.37. Annexin uptake paralleled lesion severity and macrophage burden; no correlation was observed with smooth muscle cells. DNA fragmentation staining of apoptotic nuclei was increased in advanced lesions with evolving necrotic cores, predominantly in macrophages; the uptake of radiolabel correlated with the apoptotic index. CONCLUSIONS: Because annexin V clears rapidly from blood and targets apoptotic macrophage population, it should constitute an attractive imaging agent for the noninvasive detection of unstable atherosclerotic plaques.

Optimization of the preparation of 99mTc-labeled Hynic-derivatized Annexin V for human use.

Hydrazino nicotinate (Hynic) is one of the most attractive bifunctional agents designed for the labeling of proteins with (99m)Tc. Recently, a (99m)Tc-labeled Hynic-Annexin V derivative has been described and successfully evaluated in animal models of apoptosis. Prior to a phase I human study, the preparation of (99m)Tc-Hynic-Annexin V has been optimized. The influence of the Hynic-load of Annexin V, amount of protein, nature and amount of reducing agent, activity and co-ligand on the labeling yield were evaluated using ITLC and size-exclusion FPLC. Optimal labeling yields were obtained when 60-90 microgram Hynic-Annexin V was labeled with up to 1.11 GBq (30 mCi) (99m)TcO(4)-using 10-20 microgram SnCl(2).2H(2)O as reducing agent and 1.5 mg tricine as the co-ligand. Biodistribution in normal mice was comparable to literature data.

Quantitative tumor apoptosis imaging using technetium-99m-HYNIC annexin V single photon emission computed tomography.

PURPOSE: Radiolabeled annexin V may allow for repetitive and selective in vivo identification of apoptotic cell death without the need for invasive biopsy. This study reports on the relationship between quantitative technetium-99m- (99mTc-) 6-hydrazinonicotinic (HYNIC) radiolabeled annexin V tumor uptake, and the number of tumor apoptotic cells derived from histologic analysis. PATIENTS AND METHODS: Twenty patients (18 men, two women) suspected of primary (n = 19) or recurrent (n = 1) head and neck carcinoma were included. All patients underwent a spiral computed tomography (CT) scan, 99mTc-HYNIC annexin V tomography, and subsequent surgical resection of the suspected primary or recurrent tumor. Quantitative 99mTc-HYNIC annexin V uptake in tumor lesions divided by the tumor volume, derived from CT, was related to the number of apoptotic cells per tumor high-power field derived from terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL) assays performed on sectioned tumor slices. RESULTS: Diagnosis was primary head and neck tumor in 18 patients, lymph node involvement of a cancer of unknown primary origin in one patient, and the absence of recurrence in one patient. Mean percentage absolute tumor uptake of the injected dose per cubic centimeter tumor volume derived from tomographic images was 0.0003% (standard deviation [SD], 0.0004%) at 1 hour postinjection (PI) and 0.0001% (SD, 0.0000%) at 5 to 6 hours PI (P =.012). Quantitative 99mTc-HYNIC annexin V tumor uptake correlated well with the number of apoptotic cells if only tumor samples with no or minimal amounts of necrosis were considered. CONCLUSION: In the absence of necrosis, absolute 99mTc-HYNIC annexin V tumor uptake values correlate well with the number of apoptotic cells derived from TUNEL assays.

Safety, biodistribution, and dosimetry of 99mTc-HYNIC-annexin V, a novel human recombinant annexin V for human application.

UNLABELLED: 99mTc-hydrazinonicotinamido (HYNIC)-annexin V is a novel tracer for in vivo imaging of apoptosis. The present study on humans was performed to investigate the safety of (99m)Tc-HYNIC-annexin V and to quantify the biodistribution and radiation dose. METHODS: Six healthy, male volunteers participated in the study. A dual-head gamma camera was used to acquire conjugate anterior and posterior views. Imaging started with a transmission scan using a (57)Co-flood source to obtain a map of the local thickness of the volunteer. Approximately 250 MBq of (99m)Tc-HYNIC-annexin V were injected intravenously, directly followed by a 30-min dynamic study. Whole-body scans were obtained at about 30 min, 3 h, 6 h, and 24 h after injection. Organ uptake was determined after correction for background, scatter, and attenuation. The MIRDOSE3.1 program was used to calculate organ-absorbed doses and effective dose. Signs of adverse effects were investigated by monitoring renal and liver function, hematology, blood coagulation, and vital signs (blood pressure, pulse, respiration rate, temperature, and electrocardiogram). RESULTS: The kidneys accumulated 49.7 +/- 8.1 percentage injected dose (%ID) at 3 h after injection; the liver, 13.1 +/- 1.0 %ID; the red marrow, 9.2 +/- 1.8 %ID; and the spleen, 4.6 +/- 1.6 %ID. More than 90% of the blood activity was cleared with a half-life of 24 +/- 3 min. The biologic half-life of the activity registered over the total body was long (69 +/- 7 h). Excretion of the activity was almost exclusively through the urine (22.5 +/- 3.5 %ID at 24 h), and hardly any activity was seen in the bowel or feces. Absorbed doses were found to be 196 +/- 31 micro Gy/MBq for the kidneys, 41 +/- 12 micro Gy/MBq for the spleen, 16.9 +/- 1.3 micro Gy/MBq for the liver, and 8.4 +/- 0.9 micro Gy/MBq for the red marrow. The effective dose was 11.0 +/- 0.8 micro Sv/MBq, or 2.8 +/- 0.2 mSv for the average injected activity of 250 MBq. No adverse effects were observed. CONCLUSION: (99m)Tc-HYNIC-annexin V is a safe radiopharmaceutical, having a favorable biodistribution for imaging of apoptosis in the abdominal as well as thoracic area with an acceptable radiation dose.

In vivo imaging of chemotherapy-induced apoptosis in human cancers.

RATIONALE: Induction of apoptosis in sensitive tumor cells is the main mechanism of action of chemotherapy agents in human cancers. Also, the assessment of drug-induced apoptosis soon after chemotherapy may be an early predictor of treatment efficacy. PATIENTS AND METHODS: A phase I/II study was prospectively conducted in 15 patients presenting with proven lung cancers (n = 10), breast cancers (n = 2), and lymphomas (n = 3) to assess the value of the (99m)Tc-radiolabeled recombinant human (rh) Annexin V for imaging apoptosis immediately after completion of the first course of chemotherapy. Early Annexin V findings post-chemotherapy (day+1, day+2) were also compared to the tumor status at 6 to 12 weeks post-treatment. RESULTS: All lung and lymphoma patients with an increased tracer uptake post-treatment (n = 8) had either partial or complete tumor response. Five patients with no tracer uptake had progressive disease. However, two breast cancers had a response to treatment, although no significant tracer uptake was observed. Tumor response and survival time were significantly correlated with the (99m)Tc-labeled Annexin V uptake. No serious events related to tracer administration were noted. CONCLUSION: : Preliminary results of this pilot study demonstrate the feasibility of the 99mTc-labeled Annexin V uptake for the in vivo imaging of apoptosis after one course of chemotherapy. If confirmed on larger series, these promising results may open new perspectives in the management of oncology patients.

Increased uptake of the apoptosis-imaging agent (99m)Tc recombinant human Annexin V in human tumors after one course of chemotherapy as a predictor of tumor response and patient prognosis.

PURPOSE: Many anticancer therapies exert their therapeutic effect by inducing apoptosis in target tumors. We evaluated in a Phase I study the safety and the feasibility of (99m)Tc-Annexin V for imaging chemotherapy-induced apoptosis in human cancers immediately after the first course of chemotherapy. EXPERIMENTAL DESIGN: Fifteen patients presenting with lung cancer (n = 10), lymphoma (n = 3), or breast cancer (n = 2) underwent (99m)Tc-Annexin V scintigraphy before and within 3 days after their first course of chemotherapy. Tumor response was evaluated by computed tomography and (18)F-fluoro-2-deoxy-D-glucose positron emission tomography scans, 3 months in average after completing the treatment. Median follow-up was 117 days. RESULTS: In all cases, no tracer uptake was observed before treatment. However, 24-48 h after the first course of chemotherapy, 7 patients who showed (99m)Tc-Annexin V uptake at tumor sites, suggesting apoptosis, had a complete (n = 4) or a partial response (n = 3). Conversely, 6 of the 8 patients who showed no significant posttreatment tumor uptake had a progressive disease. Despite the lack of tracer uptake after treatment, the 2 patients with breast cancer had a partial response. Overall survival and progression-free survival were significantly related to tracer uptake in treated lung cancers and lymphomas (P < 0.05). No serious adverse events were observed. CONCLUSIONS: Our preliminary results demonstrated the feasibility and the safety of (99m)Tc-Annexin V for imaging apoptosis in human tumors after the first course of chemotherapy. Initial data suggest that early (99m)Tc-Annexin V tumor uptake may be a predictor of response to treatment in-patients with late stage lung cancer and lymphoma.

Monitoring apoptosis in real time.

Many therapeutically active anticancer treatments exert their effect by the induction of apoptosis and necrosis. Serial biopsies in breast cancer patients have suggested that response to therapy correlates with early posttreatment increases in tumor apoptotic index. Radiolabeled technetium Tc 99m-recombinant human (rh) annexin V provides a noninvasive technique for imaging treatment-induced cell death. Annexin V is a naturally occurring human protein that binds avidly to membrane-associated phosphatidylserine (PS). PS is normally found only on the inner leaflet of the cell membrane double layer, but it is actively transported to the outer layer as an early event in apoptosis and becomes available for annexin binding. Annexin also gains access to PS as a result of the membrane fragmentation associated with necrosis. In vitro studies of apoptosis using fluorescein annexin have shown good correlation with assessments of apoptosis documented by nuclear DNA degradation and caspase activation. In vivo localization of intravenously administered Tc 99m-annexin V has been demonstrated in numerous preclinical models of apoptosis, including anti-Fas-mediated hepatic apoptosis, rejection of allogeneic heterotopic cardiac allografts, cyclophosphamide treatment of murine lymphoma, cyclophosphamide-induced apoptosis in bone marrow, and leukocyte apoptosis associated with abscess formation. Scintigraphic studies in humans using Tc 99m-rh annexin V have demonstrated the feasibility of imaging cell death in acute myocardial infarction, in tumors with a high apoptotic index, and in response to anti-tumor chemotherapy of non-small cell lung cancer, small-cell lung cancer, breast cancer, lymphoma, and sarcoma. Increased localization of Tc 99m-rh annexin V within 1 to 3 days of chemotherapy has been noted in some, but not all, subjects with these tumors. To date, most subjects showing increased Tc 99m-rh annexin V uptake after the first course of chemotherapy have shown objective clinical responses. A single site study in 15 subjects with 1-year follow-up has suggested that increased posttreatment Tc 99m-rh annexin uptake is associated with improved time to progression of disease and survival time. In vivo imaging of cell death may have the potential to improve the treatment of cancer patients by allowing rapid, objective, patient-by-patient assessment of the efficacy of tumor cell killing.