Feasibility of 18 F-FDG Labelling of Leucocytes in a Centre Without an On-Site Cyclotron and Monitoring of Radiation Dose to Occupational Worker in the Labelling Procedure

Abstract

Objectives:

Differentiation of infection from sterile inflammation is still a major concern for clinicians. The ¹⁸F-WBC positron emission tomography/computed tomography scan has been considered a promising tool for accurate diagnosis of infection owing to its high specificity, but it renders the availability of a medical cyclotron a necessity. The aim of the present study was to determine the feasibility of labeling leukocytes and establish the protocol in a center without the availability of an on-site medical cyclotron. The secondary aim was to monitor radiation doses to occupational workers involved in labeling of leukocytes with ¹⁸F-FDG.

Materials and Methods:

Leukocyte separation was performed and leukocytes were radiolabeled with ¹⁸F-FDG in a sterile environment according to the procedure described by Bhattacharya et al. In vitro leukocyte viability was assessed using the trypan dye exclusion technique. Labeling efficiency and yield were also estimated for all radiolabeling procedures. Whole-body and extremity doses received by the personnel involved in the radiolabeling procedure were also estimated using pocket dosimeters.

Results:

Leukocyte labeling was carried out in 35 runs, during which there were two failed labeling attempts due to clotting of the blood sample. The total time involved in the whole procedure was around 2.5 h. The average labeling efficiency was 78.01% ± 6.99% (range 63.46%–86.54%), cell viability was 98%, and the cell suspension was stable up to 4 h. The mean dose was measured as 17 μSv at the chest level and 32 μSv at the extremity level, per procedure.

Conclusions:

Labeling of leukocytes with ¹⁸F-FDG is possible at a tertiary nuclear medicine setup without the availability of an on-site medical cyclotron, with reasonable labeling efficiency of 78.01% ± 6.99%. In addition, in-house labeling of leukocytes with ¹⁸F-FDG is safe and the radiation doses incurred by the personnel during the labeling procedure are well within the occupational dose limits established by the national regulatory authority.

Introduction

The differentiation of infection from sterile inflammation is still a major concern for clinicians. Although several radiopharmaceuticals have been used for imaging of infection and inflammation, in vitro labeled leukocyte imaging using white blood cells (WBCs) labeled either with ¹¹¹In-oxine or ^99mTc-HMPAO has been established as the gold standard.¹ However, these studies were limited to γ-camera scintigraphy, and image quality and resolution were unsatisfactory.² Positron emission tomography/computed tomography (PET/CT) with ¹⁸F-FDG, although being nonspecific, has the advantage of higher spatial resolution and less time consumption than its gamma camera counterparts.

The feasibility of labeling leukocytes in vitro with ¹⁸F-FDG was first demonstrated by Osman and Danpure.³ The basic principle behind it involves accumulation of FDG mainly in metabolically active inflammatory cells, which undergo an oxidative burst during inflammatory and infectious processes.⁴ The avidity of inflammatory cells for FDG has led to efforts at labeling leukocytes with FDG in vitro, in an attempt to have the synergistic advantages of specificity of labeled leukocyte study with the anatomical resolution of PET/CT.

However, radiolabeling of leukocytes with F-18 is an exhaustive and cumbersome procedure and is associated with certain disadvantages such as the requirement of high specific activity of F-18, which renders the availability of an on-site medical cyclotron a necessity. The authors in this study have replicated the procedure used by Bhattacharya et al.⁵ for labeling of leukocytes and studied its feasibility and established the protocol for centers without the availability of an on-site cyclotron. The secondary aim of this study was to monitor radiation doses received by the occupational worker involved in labeling of leukocytes with ¹⁸F-FDG.

Materials and Methods

Leukocyte separation and radiolabeling with F-18

Leukocyte separation was performed in a manner described by Bhattacharya et al.⁵ The patient was kept nil per oral for 4 h, and subsequently, 40 mL of venous blood was collected in a heparinized syringe that was then kept upright in a stand at 37°C for 60–70 min to separate the plasma. Leukocyte/platelet-rich plasma supernatant was collected slowly into two, 14-mL, conical plastic tubes using a syringe attached with a 21 gauge butterfly needle and thereafter centrifuged at 1500 rpm for 15 min.

The platelet-poor plasma supernatant was removed and used for the final suspension of leukocytes, leaving the WBC pellet at the bottom of the tube. The white cell pellet at the bottom of the first tube was reconstituted with 2.5 mL of heparinized normal saline. Concentrated ¹⁸F-FDG (20–30 mCi) was added to the suspension. This radiolabeled suspension was kept at 37°C for 25–30 min, with gentle shaking every 5 min. During this time, the supernatant plasma was centrifuged at 2000 rpm for 25 min to obtain cell-free plasma.

After incubation, 12 mL of heparinized normal saline was added to the radiolabeled suspension, the tube was centrifuged at 1500 rpm for 5 min, and the supernatant was removed. The whole labeled cell suspension and supernatant were measured separately in a dose calibrator.

Labeling efficiencies (LEs) were calculated using the formula, LE = C/(C + W) × 100, where C is the cell-associated activity and W is the activity associated with the supernatant. The radiolabeled white cell sediment was reconstituted with 4 mL of the patient's own cell-free plasma and reinjected intravenously. The protocol has been shown in the flowchart (Fig. 1).

FIG. 1.

Flowchart showing the optimal procedure of labeling leukocytes with ¹⁸F-FDG.

Viability study

In vitro leukocyte viability was assessed using the trypan dye exclusion technique. One hundred microliters of the labeled cell suspension was transferred into a tube containing 250 μL of 0.4% trypan blue solution. The tube was allowed to stand for 5–15 min before determining the number of viable cells using a hemocytometer. Microscopic examination was performed on aliquots of labeled leukocytes at 1, 2, and 3 h after labeling.

Viable cells do not take up the dye, whereas nonviable cells do. Cell viability (V) was calculated using the formula, V = N/(N + B) × 100, where N represents the number of viable cells and B the number of trypan dye-containing cells. A minimum of 100 cells were counted for all viability measurements.

Stability test

Cell-free plasma (200–300 μL) was added to 0.5 mL of labeled leukocytes, kept at room temperature for 4 h, and centrifuged at 2000 rpm for 10 min. Radioactivity in the supernatant and labeled leukocytes was measured in a dose calibrator, and radioactivity that was eluted from the labeled cells was calculated as follows: $\begin{matrix} P e r c e n t a g e o f r a d i o a c t i v i t y e l u t e d = \frac{R a d i o a c t i v i t y i n t h e s u p e r n a t a n t \times 100}{R a d i o a c t i v i t y i n t h e l a b e l e d l e u c o c y t e s + R a d i o a c t i v i t y i n t h e s u p e r n a t a n t} \end{matrix}$ $\begin{matrix} P e r c e n t a g e o f r a d i o a c t i v i t y e l u t e d = \frac{R a d i o a c t i v i t y i n t h e s u p e r n a t a n t \times 100}{R a d i o a c t i v i t y i n t h e l a b e l e d l e u c o c y t e s + R a d i o a c t i v i t y i n t h e s u p e r n a t a n t} \end{matrix}$

Personnel monitoring

Calibrated electronic pocket dosimeters (MYDOSE mini PDM, G-9679) based on solid-state (silicon semiconductor) detectors were used to measure the whole-body and extremity doses and both dose rate and accumulated dose were displayed. The measurement of these detectors ranged from 1 μSv to 1 Sv (0.1 mrem to 100 rem) for the dose and from 1 μSv/h to 100 mSv/h (0.1 mrem/h to 10 rem/h) for the dose rate. The accuracy was within ±10%, from 10 μSv to 1 Sv (from 1 mrem to 100 rem), and linearity was within ±20%, from 10 μSv/h to 100 mSv/h (from 1 mrem/h to 10 rem/h).

Dosimeters were worn at the level of the chest and on the dorsal surface of hands at the same position for each measurement. Each worker was provided with two electronic pocket dosimeters, one for the chest level and one for the extremity level, which were worn throughout the given task. The whole-body and extremity doses received by the worker were read directly from the dosimeters and recorded at the end of the task. The time spent for each procedure was recorded.

Patient studies

Patients with elevated CRP and ESR levels, presence of either suspected or documented bacterial infection, documented infection with unknown extension of the infection, and total leukocyte count >4000/mm³ were included in the study. Exclusion criteria were age <18 years, favorable clinical response to an antibiotic treatment applied for >7 d, and pregnant/lactating patients. The institutional ethics committee approved the study protocol, and written informed consent was obtained from all patients before participation.

For the ¹⁸F-FDG leukocyte scan, patients were instructed to fast for at least for 6 h before ¹⁸F-FDG-labeled leukocyte administration. First, CT images were acquired for attenuation correction. Second, PET images were acquired from the skull base to the mid-thigh or ankle (if indicated) at 2 min per bed position on a TruFlight Select time-of-flight PET scanner (Philips) after 60 min. PET images were reconstructed iteratively using the ordered set expectation–maximization algorithm with attenuation correction.

Results

Leukocyte separation and radiolabeling with ¹⁸F-FDG

Leukocyte labeling was carried out in 35 batches using the optimized procedure shown in Figure 1. There were two failed labeling attempts due to clotting of the blood sample. One sample was processed at a time to prevent any cross-contamination of samples, which is always a concern in in vitro labeling techniques. The total time to perform the whole procedure was around 2.5 h. For the in-house labeling procedure, the average amount of ¹⁸F-FDG used was 967.55 ± 94.72 MBq (26.15 ± 2.56 mCi.).

Labeling was done by a skilled radiation worker, proficient with the procedure, under a sterile environment. The labeling efficiency demonstrated by the current study was 78.01% ± 6.99% (range 63.46%–86.54%), as shown in Table 1 (details in Supplementary Table S1). Mean activity injected into the patients was 348.2 ± 51.4 MBq (9.4 ± 1.4 mCi). During labeling, leukocytes were exhaustively collected from plasma at the end of the sedimentation period and were handled very gently. Occasional swirling of the leukocyte suspension during incubation was carried out to improve labeling efficiency.

Table 1.

Amount of Starting Activity of ¹⁸F-FDG Used, Injected Activity of ¹⁸F-FDG Leukocytes, Labeling Efficiency, and Yield of the Procedure

	Amount of ¹⁸F-FDG at the start of the procedure, MBq (mCi)	Total activity at the end of the procedure, MBq (mCi)	Radiolabeling efficiency (%)	Activity of ¹⁸F-FDG leukocytes injected into the patient, MBq (mCi)	Radiolabeling yield (%)
Mean	967.71 (26.15)	445.56 (12.4)	78.01	348.2 (9.4)	26.06
Median	984.2 (26.6)	440.3 (11.9)	79.67	361.1 (9.7)	26.50
SD	94.89 (2.56)	43.75 (1.16)	6.99	51.4 (1.4)	2.55
Range	810.3–1110 (21.9–30)	362.6–536.5 (9.8– 4.5)	63.46–86.54	240.5 – 429.6 (6.5–11.6)	21.83–30.41

Radiation exposure

All the 33 radiolabeling procedures were done by two (Radiation worker 1, n = 16, and Radiation worker 2, n = 17) qualified personnel behind an L-shield while following the three cardinal principles of radiation safety: time, distance, and shielding wherever possible. The staff were also well versed with the procedure so as to spend as little time as possible during the labeling procedure. They received a mean whole-body radiation dose of 17 μSv per procedure when an average activity of 962 MBq (26 mCi) was handled for an average time of 2 h 35 min, as shown in Table 2 (details in Supplementary Table S2).

Table 2.

Effective Whole-Body Dose and Extremity Dose Received by Radiation Workers and the Time Taken for Each Procedure of Radiolabeling of Leukocytes with ¹⁸F-FDG

				Extremity dose/procedure (μSv)
	Amount of ¹⁸F-FDG at the start of the procedure, MBq (mCi)	Duration of labeling (hrs)	Effective whole-body dose/procedure (μSv)	Left hand	Right hand
Mean	967.71 (26.15)	2:35	17.30	32.18	32.78
Median	984.2 (26.6)	2:37	17	32	32
SD	94.89 (2.56)	0.003	1.91	2.60	2.63
Range	810.3–1110 (21.9–30)	2:25–2:45	15–22	25–36	28–36

The mean extremity dose received by the radiopharmacists was 32.78 μSv/procedure for the right hand and 32.18 μSv/procedure for the left hand (Table 1). There was no significant difference between the mean doses received by the two radiation workers.

Viability

The mean cell viability of ¹⁸F-FDG-labeled leukocytes, using the trypan blue dye exclusion technique, was found to be 98%.

Stability

The labeled cell suspension was found to be stable up to 4 h, with only 2%–3% of radioactivity found in the supernatant separated from the cell suspension that had been kept at room temperature for 4 h.

Patient studies

¹⁸F-FDG-labeled leukocytes were injected into 33 patients. Normal biodistribution of ¹⁸F-FDG-labeled leukocytes was primarily noted in the reticuloendothelial system. ¹⁸F-FDG-labeled leukocytes were found to concentrate more prominently in the spleen, liver, and bone marrow. Faint urinary bladder, cerebral, and myocardial uptake was seen in WBC PET/CT because of free ¹⁸F-FDG, but no gastrointestinal uptake was seen (Fig. 2).

FIG. 2.

Figure showing biodistribution patterns of ¹⁸F-FDG-labelled leukocytes PET/CT and ¹⁸F-FDG PET/CT. MIP and fused coronal images of ¹⁸F-FDG labelled leukocytes PET CT (A, B) showing normal physiological biodistribution of labelled leukocytes in the spleen, liver and bone marrow. MIP and fused coronal images of ¹⁸F-FDG PET CT (C, D) showing normal biodistribution in brain, myocardium and renal collecting system and urinary bladder with faint activity in liver, spleen and bone marrow. MIP, maximum intensity projection.

Discussion

The concept of in vitro ¹⁸F-FDG labeling of leukocytes can be considered an important tool to demonstrate infection. This was demonstrated by the study done by Osman and Danpure.³ They found that 87% of uptake of ¹⁸F-FDG inside a WBC pellet is found in granulocytes and the uptake was dependent on the concentration of glucose in the labeling medium.

Subsequently, many studies were done on humans and animals using the same radiotracer.^6

–10 This provided the rationale of using ¹⁸F-FDG-labeled leukocytes for localization of occult infection. In addition, it was associated with the advantages of high specificity of labeled leukocytes and high spatial resolution of PET/CT and significantly reduced imaging time compared with the SPECT-based counterparts (⁶⁷Ga requires 48–72 h and ^99mTc- or 111In-labeled leukocytes require up to 24 h).¹⁰

To the authors' knowledge, this is the first study showing the feasibility of F-18 FDG labeling of leukocytes in a tertiary center without an on-site medical cyclotron and monitoring of personnel during the labeling procedure.

¹⁸F-FDG labeling of leukocytes in the current study was a multistep procedure and required around 2.5 h. The leukocyte labeling efficiency is quite variable because of several factors such as proficiency of the radiation worker, blood sampling, volume of plasma obtained, incubation time, and temperature of the reaction. Different studies have quoted different labeling techniques as well as their labeling efficiency.

The labeling efficiency demonstrated in the study by Schauwecker¹¹ ranged from 24% to 96% (41%). Forstrom et al.¹² reported a labeling efficiency of 62.7%, which was further enhanced to 78.1% by mixing during incubation. In another study done by Rini et al.,¹⁰ the mean labeling efficiency of 72% ± 8% for ¹⁸F-FDG-labeled leukocytes was reported.

In a study done by Lafont et al.,¹³ the average labeling efficiency of ¹⁸F-FDG-labeled leukocytes in six healthy volunteers was reported as 90.8%. The mean labeling efficiency demonstrated by the current study was 78.01% ± 6.99% (range 51%–92%) in 33 batches, which was slightly lower than that reported by Bhattacharya et al.⁵ (81% ± 17%). One of the factors known to be conducive for high labeling efficiency is the requirement of high specific activity of ¹⁸F-FDG for labeling leukocytes.

Since Bhattacharya et al.⁵ had the advantage of an on-site cyclotron, which allows the usage of high specific activity ¹⁸F-FDG, it could be the reason for their higher labeling efficiency compared with that calculated in this study. The authors received ¹⁸F-FDG from a commercial cyclotron, and despite all their efforts, a time equivalent to 1.5 half-life of F-18 (∼3 h) would elapse for it to reach their center before the labeling started, which results in slightly lower specific activity. This difference also resulted in the usage of a higher amount of starting activity, 1110 MBq, at their center compared with 370 MBq used by Bhattacharya et al.⁵

Despite the lower specific activity, the authors were successful in having a comparable and reasonable average labeling efficiency of 78.01% ± 6.99% and getting a good quality image. The ¹⁸F-FDG-labeled leukocytes were injected into patients for evaluation of occult infection and also compared with ¹⁸F-FDG to evaluate its incremental value, as shown in Figures 3 and 4; however, the clinical results will be shown in a separate study.

FIG. 3.

Figure showing superior diagnostic efficacy of ¹⁸F-FDG leukocyte PET/CT in finding an additional site of infection. MIP and fused coronal images of the ¹⁸F-FDG leukocyte PET/CT scan (A–C) showing intense tracer uptake in an ill-defined hypoattenuated abscess in a transplanted kidney (B–white arrow ) with tracer uptake in the terminal ileum (B–white arrowhead ) and an isodense lesion in the anterior compartment of the right leg (C–white arrow ). MIP and fused coronal images of the ¹⁸F-FDG PET CT scan (D–F) showing ¹⁸F-FDG uptake in an abscess in a transplanted kidney (E–white arrowhead ) and ¹⁸F-FDG uptake in a lesion in the right leg (F–white arrow ). FNAC from the nodular swelling in the lower limb revealed mucormycosis. The additional site of infection, which was noted at the ileocecal junction in ¹⁸F-FDG labelled leukocytes PET/CT, was not visible on ¹⁸F-FDG PET/CT scans. FNAC, fine needle aspiration cytology.

FIG. 4.

Figure showing superior diagnostic efficacy of ¹⁸F-FDG leukocyte PET/CT. MIP and fused coronal images of the ¹⁸F-FDG leukocyte PET/CT scan (A, B) showing no abnormal accumulation of labeled leukocytes in mediastinal lymph nodes (B-white arrow). MIP and fused coronal images of the ¹⁸F-FDGPET/ CT (C, D) scan showing intense tracer uptake in the mediastinal lymph nodes (D-white arrow). FNAC of the mediastinal lymph nodes revealed reactive lymphadenitis.

Nevertheless, the authors emphasize that the diagnostic performance of ¹⁸F-FDG-labeled leukocyte PET/CT is higher than the till date gold standard ^99mTc-HMPAO owing to the high spatial resolution of PET/CT and early whole-body imaging. In view of the above discussion, the authors can also conclude that labeling of leukocytes with ¹⁸F-FDG is also possible at a tertiary health care nuclear medicine setup without the availability of an on-site cyclotron.

In the present study, the mean cell viability of ¹⁸F-FDG-labeled leukocytes, using the trypan blue dye exclusion technique, was 98%, which was comparable with that reported by Forstrom et al.¹² (100%) and Bhattacharya et al.⁵ (99%).

Since ¹⁸F is associated with the emission of very high gamma energy of 511 keV photons and manipulation with the activity can be performed for the longer time of 2–2.5 h, significant radiation exposure to their hands, particularly the fingers, is expected. Therefore, conducting monitoring of radiation workers is of prime importance as it can serve as a guide to determine if any modification is needed in work practices and also to evaluate the numbers of procedures that can be conducted safely per year by complying with regulatory limits.

According to the 2007 recommendations of the International Commission on Radiological Protection (ICRP), the effective radiation dose to personnel should not exceed 20 mSv/y averaged over 5 years or 50 mSv in any year.¹⁴ Whole-body radiation exposure to the staff performing the labeling procedure, as ascertained by the chest electronic pocket dosimeter, varied from 15 to 22 μSv (17 ± 1.4 μSv) and the extremity dose varied from 25 to 36 μSv per procedure. Three factors responsible for the radiation dose are the amount of radioactivity handled, time of manipulation with the radioactivity, and distance at which the radioactivity is held.

Many studies were found in the literature reporting the whole-body and extremity radiation doses incurred by personnel while handling, injecting, and scanning ¹⁸F-FDG patients; for example, Zeff and Yester¹⁵ reported a whole-body dose of 8.9 μSv, Chiesa et al.¹⁶ reported 8.5 μSv, Biran et al.¹⁷ reported 7.2 μSv, and Benatar et al. reported 6.5 μSv,¹⁸ but only one study by Bhattacharya et al.⁵ was found reporting on the radiation dose received by radiation workers during labeling of leukocytes with ¹⁸F-FDG for direct comparison. They also used electronic pocket dosimeters, which were worn at the chest level, and reported a lower whole-body effective dose in the range of 4–10 μSv (5.6 ± 1.4 μSv) received by the staff performing the labeling procedure for each patient.

However, it is difficult to compare these doses between institutes because of the variability in the conditions in each individual facility, such as the procedure, the activity handled, staff proficiency, and shielding devices. The authors could conclude that the major reason for a higher dose in the current study could be the amount of starting activity, which is handled by the staff. The starting activity in the current study was approximately threefold higher than used in the study by Bhattacharya et al. (26.6 ± 2.56 mCi vs. 11.5 ± 1.6 mCi) and hence, higher the radiation exposure.

Even if a higher mean whole-body effective dose of 17 μSv received by an occupational worker during one procedure is considered, it would allow ∼1100 such procedures to be performed per year before reaching the regulatory authority-stipulated annual limit of 20 mSv averaged over 5 years. Thus, assuming six cases per week, potentially 312 procedures per year could be performed, which are far fewer (28%) than the number it would take to reach the allowed limit.

The mean dose to the extremities of a radiation worker was 32 μSv, ranging from 25 to 36 μSv/procedure. If the same radiation worker were to continue to work for a whole year, the worker could perform over 1500 procedures before reaching the threshold for the extremities (50 mSv; i.e., one-tenth of the annual extremity dose limit of 500 mSv). The readings from the chest and wrist thermoluminescent dosimeter badges were 0.5 and 0.56 mSv, respectively, for both the radiation workers engaged in labeling of leukocytes with ¹⁸F-FDG as well as the routine departmental work during the 6-month monitoring period.

These doses were well within permissible limits and were not significantly higher than the doses received by workers who performed routine departmental work alone. Therefore, the chances of exceeding the prescribed annual limit for these workers were unlikely in the authors' practice, although staff were always motivated and trained to keep the cardinal principles of radiation safety in mind.

In addition, this study reported comparable doses to the left and right hands as both hands were used equally in the labeling procedure.

Conclusions

This study confirms that labeling of leukocytes with ¹⁸F-FDG is possible at a tertiary nuclear medicine setup without the availability of an on-site medical cyclotron, with reasonable labeling efficiency of 78.01% ± 6.99%.

In addition, in-house labeling of leukocytes with ¹⁸F-FDG is safe and the radiation doses incurred by the personnel during the labeling procedure are well within the occupational dose limits established by the national regulatory authority.

Footnotes

Acknowledgments

The authors acknowledge Prof. Anish Bhattacharya of the Department of Nuclear Medicine, PGIMER, Chandigarh, and his team who shared the protocol and helped with the labeling technique.

Authors' Contributions

All authors contributed significantly to the content of the article. The manuscript has been seen and approved by all authors.

Disclosure Statement

The authors declare that they have no conflicts of interest.

Funding Information

The study was not funded by any funding agency.

Supplementary Material

Supplementary Table S1

Supplementary Table S2

References

Das

, Hall

, Wareham

, et al. Infection imaging with radiopharmaceuticals in 21st century. Infection and Inflammation. Braz Arch Biol Technol, 2002; 45:25.

Vaidyanathan

, Patel

, Scarsbrook

, et al. FDG PET/CT in infection and inflammation—current and emerging clinical applications. Clin Radiol, 2015; 70:787.

Osman

, Danpure

. The use of 2-[18F] fluoro-2-deoxy-D-glucose as a potential in vitro agent for labelling human granulocytes for clinical studies by positron emission tomography. Int J Rad Appl Instrum B, 1992; 19:183.

Dumarey

, Egrise

, Blocklet

, et al. Imaging Infection with ¹⁸F-FDG–Labeled Leukocyte PET/CT: Initial Experience in 21 Patients. J Nucl Med, 2006; 47:625.

Bhattacharya

, Kochhar

, Sharma

, et al. PET/CT with 18F-FDG –labeled autologous leukocytes for the diagnosis of infected fluid collections in acute pancreatitis. J Nucl Med, 2014; 55:1267.

Meyer

, Testart

, Jreige

, et al. Diagnostic performance of PET or PET/CT using ¹⁸F-FDG labeled white blood cells in infectious diseases: A systematic review and a bivariate meta-analysis. Diagnostics, 2019; 9:60.

Kim

, Oh

, Park

, et al. Clinical experience with white blood cell-PET/CT in autosomal dominant polycystic kidney disease patients with suspected cyst infection: A prospective case series. Nephrology, 2018; 23:661.

Kwon

, Lee

, Hwang

, et al. Diagnostic performance of ¹⁸F-FDG-labeled white blood cell PET/CT for cyst infection in patients with autosomal dominant polycystic kidney disease: A prospective study. Nucl Med Commun, 2016; 37:493.

Aksoy

, Asa

, Ozhan

, et al. FDG and FDG-labelled leucocyte PET/CT in the imaging of prosthetic joint infection. Eur J Nucl Med Mol Imaging, 2014; 41:556.

10.

Rini

, Bhargava

, Tronco

, et al. PET with FDG-labeled leukocytes versus scintigraphy with 111In-oxine-labeled leukocytes for detection of infection. Radiology, 2006; 238:978.

11.

Schauwecker

. Osteomyelitis: Diagnosis with In-111-labeled leukocytes. Radiology, 1989; 171:141.

12.

Forstrom

, Mullan

, Hung

, et al. ¹⁸F-FDG labeling of human leukocytes. Nucl Med Commun, 2000; 21:691.

13.

Lafont

, Morelec

, Fraysse

, et al. ¹⁸F-FDG labelled leukocytes in vitro functional tests: Viability, chemotaxis and phagocytosis assays. Open Nucl Med J, 2011; 3:25.

14.

The 2007 recommendations of the International Commission on Radiological Protection: ICRP publication 103. Ann ICRP, 2007; 37:1.

15.

Zeff

, Yester

. Patient self-attenuation and technologist dose in positron emission tomography. Med Phys, 2005; 32:861.

16.

Chiesa

, De Sanctis

, Crippa

. Radiation dose to technicians per nuclear medicine procedure: Comparison between technetium-99m, gallium-67, and iodine-131 radiotracers and fluorine-18 fluorodeoxyglucose. Eur J Nucl Med, 1997; 24:1380.

17.

Biran

, Weininger

, Malchi

, et al. Measurements of occupational exposure for a technologist performing ¹⁸F-FDG scans. Health Phys, 2004; 87:539.

18.

Benatar

, Cronin

, O'Dohery

. Radiation dose rates from patients undergoing PET: Implication for technologists and waiting areas. Eur J Nucl Med, 2000; 27:583.

Supplementary Material

Please find the following supplemental material available below.

For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.

For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.

0.00 MB

0.02 MB

Feasibility of 18 F-FDG Labelling of Leucocytes in a Centre Without an On-Site Cyclotron and Monitoring of Radiation Dose to Occupational Worker in the Labelling Procedure

Abstract

Objectives:

Materials and Methods:

Results:

Conclusions:

Introduction

Materials and Methods

Leukocyte separation and radiolabeling with F-18

Viability study

Stability test

Personnel monitoring

Patient studies

Results

Leukocyte separation and radiolabeling with 18F-FDG

Radiation exposure

Viability

Stability

Patient studies

Discussion

Conclusions

Footnotes

Acknowledgments

Authors' Contributions

Disclosure Statement

Funding Information

Supplementary Material

References

Supplementary Material

Leukocyte separation and radiolabeling with ¹⁸F-FDG