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Article ; Online: Use of population input functions for reduced scan duration whole-body Patlak 18F-FDG PET imaging

Joyce van Sluis / Maqsood Yaqub / Adrienne H. Brouwers / Rudi A. J. O. Dierckx / Walter Noordzij / Ronald Boellaard

EJNMMI Physics, Vol 8, Iss 1, Pp 1-

2021 Volume 8

Abstract: Abstract Whole-body Patlak images can be obtained from an acquisition of first 6 min of dynamic imaging over the heart to obtain the arterial input function (IF), followed by multiple whole-body sweeps up to 60 min pi. The use of a population-averaged IF ...

Abstract	Abstract Whole-body Patlak images can be obtained from an acquisition of first 6 min of dynamic imaging over the heart to obtain the arterial input function (IF), followed by multiple whole-body sweeps up to 60 min pi. The use of a population-averaged IF (PIF) could exclude the first dynamic scan and minimize whole-body sweeps to 30–60 min pi. Here, the effects of (incorrect) PIFs on the accuracy of the proposed Patlak method were assessed. In addition, the extent of mitigating these biases through rescaling of the PIF to image-derived IF values at 30–60 min pi was evaluated. Methods Using a representative IF and rate constants from the literature, various tumour time-activity curves (TACs) were simulated. Variations included multiplication of the IF with a positive and negative gradual linear bias over 60 min of 5, 10, 15, 20, and 25% (generating TACs using an IF different from the PIF); use of rate constants (K 1, k 3, and both K 1 and k 2) multiplied by 2, 1.5, and 0.75; and addition of noise (μ = 0 and σ = 5, 10 and 15%). Subsequent Patlak analysis using the original IF (representing the PIF) was used to obtain the influx constant (K i ) for the differently simulated TACs. Next, the PIF was scaled towards the (simulated) IF value using the 30–60-min pi time interval, simulating scaling of the PIF to image-derived values. Influence of variabilities in IF and rate constants, and rescaling the PIF on bias in K i was evaluated. Results Percentage bias in K i observed using simulated modified IFs varied from − 16 to 16% depending on the simulated amplitude and direction of the IF modifications. Subsequent scaling of the PIF reduced these K i biases in most cases (287 out of 290) to < 5%. Conclusions Simulations suggest that scaling of a (possibly incorrect) PIF to IF values seen in whole-body dynamic imaging from 30 to 60 min pi can provide accurate Ki estimates. Consequently, dynamic Patlak imaging protocols may be performed for 30–60 min pi making whole-body Patlak imaging clinically feasible.
Keywords	Patlak ; PET/CT ; Dynamic imaging ; Population input function ; Scan time ; Medical physics. Medical radiology. Nuclear medicine ; R895-920
Language	English
Publishing date	2021-02-01T00:00:00Z
Publisher	SpringerOpen
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Convolutional neural networks for automatic image quality control and EARL compliance of PET images

Elisabeth Pfaehler / Daniela Euba / Andreas Rinscheid / Otto S. Hoekstra / Josee Zijlstra / Joyce van Sluis / Adrienne H. Brouwers / Constantin Lapa / Ronald Boellaard

EJNMMI Physics, Vol 9, Iss 1, Pp 1-

2022 Volume 13

Abstract: Abstract Background Machine learning studies require a large number of images often obtained on different PET scanners. When merging these images, the use of harmonized images following EARL-standards is essential. However, when including retrospective ... ...

Abstract	Abstract Background Machine learning studies require a large number of images often obtained on different PET scanners. When merging these images, the use of harmonized images following EARL-standards is essential. However, when including retrospective images, EARL accreditation might not have been in place. The aim of this study was to develop a convolutional neural network (CNN) that can identify retrospectively if an image is EARL compliant and if it is meeting older or newer EARL-standards. Materials and methods 96 PET images acquired on three PET/CT systems were included in the study. All images were reconstructed with the locally clinically preferred, EARL1, and EARL2 compliant reconstruction protocols. After image pre-processing, one CNN was trained to separate clinical and EARL compliant reconstructions. A second CNN was optimized to identify EARL1 and EARL2 compliant images. The accuracy of both CNNs was assessed using fivefold cross-validation. The CNNs were validated on 24 images acquired on a PET scanner not included in the training data. To assess the impact of image noise on the CNN decision, the 24 images were reconstructed with different scan durations. Results In the cross-validation, the first CNN classified all images correctly. When identifying EARL1 and EARL2 compliant images, the second CNN identified 100% EARL1 compliant and 85% EARL2 compliant images correctly. The accuracy in the independent dataset was comparable to the cross-validation accuracy. The scan duration had almost no impact on the results. Conclusion The two CNNs trained in this study can be used to retrospectively include images in a multi-center setting by, e.g., adding additional smoothing. This method is especially important for machine learning studies where the harmonization of images from different PET systems is essential.
Keywords	PET ; Image quality ; Convolutional neural network ; Medical physics. Medical radiology. Nuclear medicine ; R895-920
Subject code	571
Language	English
Publishing date	2022-08-01T00:00:00Z
Publisher	SpringerOpen
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Shortened duration whole body 18F-FDG PET Patlak imaging on the Biograph Vision Quadra PET/CT using a population-averaged input function

Joyce van Sluis / Johannes H. van Snick / Adrienne H. Brouwers / Walter Noordzij / Rudi A. J. O. Dierckx / Ronald J. H. Borra / Adriaan A. Lammertsma / Andor W. J. M. Glaudemans / Riemer H. J. A. Slart / Maqsood Yaqub / Charalampos Tsoumpas / Ronald Boellaard

EJNMMI Physics, Vol 9, Iss 1, Pp 1-

2022 Volume 14

Abstract: Abstract Background Excellent performance characteristics of the Vision Quadra PET/CT, e.g. a substantial increase in sensitivity, allow for precise measurements of image-derived input functions (IDIF) and tissue time activity curves. Previously we have ... ...

Abstract	Abstract Background Excellent performance characteristics of the Vision Quadra PET/CT, e.g. a substantial increase in sensitivity, allow for precise measurements of image-derived input functions (IDIF) and tissue time activity curves. Previously we have proposed a method for a reduced 30 min (as opposed to 60 min) whole body 18F-FDG Patlak PET imaging procedure using a previously published population-averaged input function (PIF) scaled to IDIF values at 30–60 min post-injection (p.i.). The aim of the present study was to apply this method using the Vision Quadra PET/CT, including the use of a PIF to allow for shortened scan durations. Methods Twelve patients with suspected lung malignancy were included and received a weight-based injection of 18F-FDG. Patients underwent a 65-min dynamic PET acquisition which were reconstructed using European Association of Nuclear Medicine Research Ltd. (EARL) standards 2 reconstruction settings. A volume of interest (VOI) was placed in the ascending aorta (AA) to obtain the IDIF. An external PIF was scaled to IDIF values at 30–60, 40–60, and 50–60 min p.i., respectively, and parametric 18F-FDG influx rate constant (K i ) images were generated using a t* of 30, 40 or 50 min, respectively. Herein, tumour lesions as well as healthy tissues, i.e. liver, muscle tissue, spleen and grey matter, were segmented. Results Good agreement between the IDIF and corresponding PIF scaled to 30–60 min p.i. and 40–60 min p.i. was obtained with 7.38% deviation in K i . Bland–Altman plots showed excellent agreement in K i obtained using the PIF scaled to the IDIF at 30–60 min p.i. and at 40–60 min p.i. as all data points were within the limits of agreement (LOA) (− 0.004–0.002, bias: − 0.001); for the 50–60 min p.i. K i , all except one data point fell in between the LOA (− 0.021–0.012, bias: − 0.005). Conclusions Parametric whole body 18F-FDG Patlak K i images can be generated non-invasively on a Vision Quadra PET/CT system. In addition, using a scaled PIF allows for a substantial (factor 2 to 3) ...
Keywords	Patlak ; Dynamic imaging ; Vision Quadra ; PET/CT ; Scan duration ; Medical physics. Medical radiology. Nuclear medicine ; R895-920
Subject code	610
Language	English
Publishing date	2022-10-01T00:00:00Z
Publisher	SpringerOpen
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Volume of interest delineation techniques for 18F-FDG PET-CT scans during neoadjuvant extremity soft tissue sarcoma treatment in adults

Marc G. Stevenson / Lukas B. Been / Harald J. Hoekstra / Albert J. H. Suurmeijer / Ronald Boellaard / Adrienne H. Brouwers

EJNMMI Research, Vol 8, Iss 1, Pp 1-

a feasibility study

2018 Volume 11

Abstract: Abstract Background This study explores various volume of interest (VOI) delineation techniques for fluorine-18-fluorodeoxyglucose positron emission tomography with computed tomography (18F-FDG PET-CT) scans during neoadjuvant extremity soft tissue ... ...

Abstract	Abstract Background This study explores various volume of interest (VOI) delineation techniques for fluorine-18-fluorodeoxyglucose positron emission tomography with computed tomography (18F-FDG PET-CT) scans during neoadjuvant extremity soft tissue sarcoma (ESTS) treatment. Results During neoadjuvant treatment, hyperthermic isolated limb perfusion (HILP) and preoperative external beam radiotherapy (EBRT), 11 patients underwent three 18F-FDG PET-CT scans. The first scan was made prior to the HILP, the second after the HILP but prior to the start of the EBRT, and the third prior to surgical resection. An automatically drawn VOIauto, a manually drawn VOIman, and two gradient-based semi-automatically drawn VOIs (VOIgrad and VOIgrad+) were obtained. Maximum standardized uptake value (SUVmax), SUVpeak, SUVmean, metabolically active tumor volume (MATV), and total lesion glycolysis (TLG) were calculated from each VOI. The correlation and level of agreement between VOI delineation techniques was explored. Lastly, the changes in metabolic tumor activity were related to the histopathologic response. The strongest correlation and an acceptable level of agreement was found between the VOIman and the VOIgrad+ delineation techniques. A decline (VOIman) in SUVmax, SUVpeak, SUVmean, TLG, and MATV (all p < 0.05) was found between the three scans. A > 75% decline in TLG between scan 1 and scan 3 possibly identifies histopathologic response. Conclusions The VOIgrad+ delineation technique was identified as most reliable considering reproducibility when compared with the other VOI delineation techniques during the multimodality neoadjuvant treatment of locally advanced ESTS. A significant decline in metabolic tumor activity during the treatment was found. TLG deserves further exploration as predictor for histopathologic response after multimodality ESTS treatment.
Keywords	Soft tissue sarcoma ; 18F-FDG PET-CT ; Limb perfusion ; Preoperative radiotherapy ; Medical physics. Medical radiology. Nuclear medicine ; R895-920
Subject code	616
Language	English
Publishing date	2018-06-01T00:00:00Z
Publisher	SpringerOpen
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: PET segmentation of bulky tumors

Elisabeth Pfaehler / Coreline Burggraaff / Gem Kramer / Josée Zijlstra / Otto S Hoekstra / Mathilde Jalving / Walter Noordzij / Adrienne H Brouwers / Marc G Stevenson / Johan de Jong / Ronald Boellaard

PLoS ONE, Vol 15, Iss 3, p e

Strategies and workflows to improve inter-observer variability.

2020 Volume 0230901

Abstract: Background PET-based tumor delineation is an error prone and labor intensive part of image analysis. Especially for patients with advanced disease showing bulky tumor FDG load, segmentations are challenging. Reducing the amount of user-interaction in the ...

Abstract	Background PET-based tumor delineation is an error prone and labor intensive part of image analysis. Especially for patients with advanced disease showing bulky tumor FDG load, segmentations are challenging. Reducing the amount of user-interaction in the segmentation might help to facilitate segmentation tasks especially when labeling bulky and complex tumors. Therefore, this study reports on segmentation workflows/strategies that may reduce the inter-observer variability for large tumors with complex shapes with different levels of user-interaction. Methods Twenty PET images of bulky tumors were delineated independently by six observers using four strategies: (I) manual, (II) interactive threshold-based, (III) interactive threshold-based segmentation with the additional presentation of the PET-gradient image and (IV) the selection of the most reasonable result out of four established semi-automatic segmentation algorithms (Select-the-best approach). The segmentations were compared using Jaccard coefficients (JC) and percentage volume differences. To obtain a reference standard, a majority vote (MV) segmentation was calculated including all segmentations of experienced observers. Performed and MV segmentations were compared regarding positive predictive value (PPV), sensitivity (SE), and percentage volume differences. Results The results show that with decreasing user-interaction the inter-observer variability decreases. JC values and percentage volume differences of Select-the-best and a workflow including gradient information were significantly better than the measurements of the other segmentation strategies (p-value<0.01). Interactive threshold-based and manual segmentations also result in significant lower and more variable PPV/SE values when compared with the MV segmentation. Conclusions FDG PET segmentations of bulky tumors using strategies with lower user-interaction showed less inter-observer variability. None of the methods led to good results in all cases, but use of either the gradient or the ...
Keywords	Medicine ; R ; Science ; Q
Subject code	004
Language	English
Publishing date	2020-01-01T00:00:00Z
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: The effects of molar activity on [18F]FDOPA uptake in patients with neuroendocrine tumors

Gilles N. Stormezand / Romano S. B. H. Schreuder / Adrienne H. Brouwers / Riemer H. J. A. Slart / Philip H. Elsinga / Annemiek M. E. Walenkamp / R. A. J. O. Dierckx / Andor W. J. M. Glaudemans / Gert Luurtsema

EJNMMI Research, Vol 11, Iss 1, Pp 1-

2021 Volume 8

Abstract: Abstract Background 6-[18F]fluoro-l-3,4-dihydroxyphenyl alanine ([18F]FDOPA) is a commonly used PET tracer for the detection and staging of neuroendocrine tumors. In neuroendocrine tumors, [18F]FDOPA is decarboxylated to [18F]dopamine via the enzyme ... ...

Abstract	Abstract Background 6-[18F]fluoro-l-3,4-dihydroxyphenyl alanine ([18F]FDOPA) is a commonly used PET tracer for the detection and staging of neuroendocrine tumors. In neuroendocrine tumors, [18F]FDOPA is decarboxylated to [18F]dopamine via the enzyme amino acid decarboxylase (AADC), leading to increased uptake when there is increased AADC activity. Recently, in our hospital, a new GMP compliant multi-dose production of [18F]FDOPA has been developed, [18F]FDOPA-H, resulting in a higher activity yield, improved molar activity and a lower administered mass than the conventional method ([18F]FDOPA-L). Aims This study aimed to investigate whether the difference in molar activity affects the [18F]FDOPA uptake at physiological sites and in tumor lesions, in patients with NET. It was anticipated that the specific uptake of [18F]FDOPA-H would be equal to or higher than [18F]FDOPA-L. Methods We retrospectively analyzed 49 patients with pathologically confirmed NETs and stable disease who underwent PET scanning using both [18F]FDOPA-H and [18F]FDOPA-L within a time span of 5 years. A total of 98 [18F]FDOPA scans (49 [18F]FDOPA-L and 49 [18F]FDOPA-H with average molar activities of 8 and 107 GBq/mmol) were analyzed. The SUVmean was calculated for physiological organ uptake and SUVmax for tumor lesions in both groups for comparison, and separately in subjects with low tumor load (1–2 lesions) and higher tumor load (3–10 lesions). Results Comparable or slightly higher uptake was demonstrated in various physiological uptake sites in subjects scanned with [18F]FDOPA-H compared to [18F]FDOPA-L, with large overlap being present in the interquartile ranges. Tumor uptake was slightly higher in the [18F]FDOPA-H group with 3–10 lesion (SUVmax 6.83 vs. 5.19, p < 0.001). In the other groups, no significant differences were seen between H and L. Conclusion [18F]FDOPA-H provides a higher activity yield, offering the possibility to scan more patients with one single production. Minor differences were observed in SUV’s, with slight ...
Keywords	[18F]-FDOPA ; Neuroendocrine tumors ; Molar activity ; Biodistribution ; Medical physics. Medical radiology. Nuclear medicine ; R895-920
Subject code	610
Language	English
Publishing date	2021-09-01T00:00:00Z
Publisher	SpringerOpen
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Mapping heterogeneity in glucose uptake in metastatic melanoma using quantitative 18F-FDG PET/CT analysis

Ellen C. de Heer / Adrienne H. Brouwers / Ronald Boellaard / Wim J. Sluiter / Gilles F. H. Diercks / Geke A. P. Hospers / Elisabeth G. E. de Vries / Mathilde Jalving

EJNMMI Research, Vol 8, Iss 1, Pp 1-

2018 Volume 9

Abstract: Abstract Background Metastatic melanoma patients can have durable responses to systemic therapy and even long-term survival. However, a large subgroup of patients does not benefit. Tumour metabolic alterations may well be involved in the efficacy of both ...

Abstract	Abstract Background Metastatic melanoma patients can have durable responses to systemic therapy and even long-term survival. However, a large subgroup of patients does not benefit. Tumour metabolic alterations may well be involved in the efficacy of both targeted and immunotherapy. Knowledge on in vivo tumour glucose uptake and its heterogeneity in metastatic melanoma may aid in upfront patient selection for novel (concomitant) metabolically targeted therapies. The aim of this retrospective study was to provide insight into quantitative 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) parameters and corresponding intra- and inter-patient heterogeneity in tumour 18F-FDG uptake among metastatic melanoma patients. Consecutive, newly diagnosed stage IV melanoma patients with a baseline 18F-FDG PET/CT scan performed between May 2014 and December 2015 and scheduled to start first-line systemic treatment were included. Volume of interests (VOIs) of all visible tumour lesions were delineated using a gradient-based contour method, and standardized uptake values (SUVs), metabolically active tumour volume (MATV) and total lesion glycolysis (TLG) were determined on a per-lesion and per-patient basis. Differences in quantitative PET parameters were explored between patient categories stratified by BRAF V600 and RAS mutational status, baseline serum lactate dehydrogenase (LDH) levels and tumour programmed death-ligand 1 (PD-L1) expression. Results In 64 patients, 1143 lesions ≥ 1 ml were delineated. Median number of lesions ≥ 1 ml was 6 (range 0–168), median maximum SUVpeak 9.5 (range 0–58), median total MATV 29 ml (range 0–2212) and median total TLG 209 (range 0–16,740). Per-patient analysis revealed considerable intra- and inter-patient heterogeneity. Maximum SUVs, MATV, number of lesions and TLG per patient did not differ when stratifying between BRAF V600 or RAS mutational status or PD-L1 expression status, but were higher in the patient group with elevated LDH levels (> 250 U/l) ...
Keywords	Stage IV melanoma ; 18F-FDG PET/CT ; Metabolism ; SUV ; LDH ; Medical physics. Medical radiology. Nuclear medicine ; R895-920
Subject code	616
Language	English
Publishing date	2018-11-01T00:00:00Z
Publisher	SpringerOpen
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Optimization of parathyroid 11C-choline PET protocol for localization of parathyroid adenomas in patients with primary hyperparathyroidism

Milou E. Noltes / Schelto Kruijff / Walter Noordzij / Eef D. Telenga / David Vállez García / Malgorzata Trofimiuk-Müldner / Marta Opalińska / Alicja Hubalewska-Dydejczyk / Gert Luurtsema / Rudi A. J. O. Dierckx / Mostafa El Moumni / Ronald Boellaard / Adrienne H. Brouwers

EJNMMI Research, Vol 9, Iss 1, Pp 1-

2019 Volume 10

Abstract: Abstract Purpose To evaluate the optimal tracer uptake time, the minimal amount of radioactivity and the inter-observer agreement for 11C-choline positron emission tomography/computed tomography (PET/CT) in patients with primary hyperparathyroidism (pHPT) ...

Abstract	Abstract Purpose To evaluate the optimal tracer uptake time, the minimal amount of radioactivity and the inter-observer agreement for 11C-choline positron emission tomography/computed tomography (PET/CT) in patients with primary hyperparathyroidism (pHPT). Methods Twenty-one patients with biochemically proven pHPT were retrospectively studied after injection of 6.3 ± 1.2 MBq/kg 11C-choline. PET data of the first nine patients, scanned for up to 60 min, were reconstructed in 10-min frames from 10- to 60-min postinjection (p.i.), mimicking varying 11C-choline uptake times. Parathyroid adenoma to background contrast ratios were calculated and compared, using standardized uptake values (SUVs). Data was reconstructed with varying scan durations (1, 2.5, 5, and 10 min) at 20–30-min p.i. (established optimal uptake time), mimicking less administered radioactivity. To establish the minimal required radioactivity, the SUVs in the shorter scan durations (1, 2.5, and 5 min) were compared to the 10-min scan duration to determine whether increased variability and/or statistical differences were observed. Four observers analyzed the 11C-choline PET/CT in four randomized rounds for all patients. Results SUVpeak of the adenoma decreased from 30 to 40 p.i. onwards. All adenoma/background contrast ratios did not differ from 20- to 30-min p.i. onwards. The SUVs of adenoma in the scan duration of 1, 2.5, and 5 min all differed significantly from the same SUV in the 10-min scan duration (all p = 0.012). However, the difference in absolute SUV adenoma values was well below 10% and therefore not considered clinically significant. The inter-observer analysis showed that the Fleiss’ kappa of the 1-min scan were classified as “moderate,” while these values were classified as “good” in the 2.5-, 5-, and 10-min scan duration. Observers scored lower certainty scores in the 1- and 2.5-min scans compared to the 5- and 10-min scan durations. Conclusion The optimal time to start PET/CT scanning in patients with pHPT is 20 min after mean ...
Keywords	Primary hyperparathyroidism ; 11C-Choline PET ; Inter-observer agreement ; Scan protocol ; Medical physics. Medical radiology. Nuclear medicine ; R895-920
Subject code	610
Language	English
Publishing date	2019-07-01T00:00:00Z
Publisher	SpringerOpen
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: In-Trastuzumab Scintigraphy in HER2-Positive Metastatic Breast Cancer Patients Remains Feasible during Trastuzumab Treatment

Sietske B.M. Gaykema / Johan R. de Jong / Patrick J. Perik / Adrienne H. Brouwers / Carolien P. Schröder / Thijs H. Oude Munnink / Alphons H.H. Bongaerts / Elisabeth G.E. de Vries / Marjolijn N. Lub-de Hooge

Molecular Imaging, Vol

2014 Volume 13

Abstract: Human epidermal growth factor receptor (HER)2 imaging with radiolabeled trastuzumab might support HER2-targeted therapy. It is, however, frequently questioned whether HER2 imaging is also possible during trastuzumab treatment as the receptor might be ... ...

Abstract	Human epidermal growth factor receptor (HER)2 imaging with radiolabeled trastuzumab might support HER2-targeted therapy. It is, however, frequently questioned whether HER2 imaging is also possible during trastuzumab treatment as the receptor might be saturated. We studied the effect of trastuzumab treatment on 111 In-trastuzumab uptake. Patients received trastuzumab weekly and paclitaxel once every 3 weeks. 111 In-trastuzumab was injected on day 1 of cycle 1 and day 15 of cycle 4. Whole-body planar scintigraphy was acquired at different time points postinjection. Tumor uptake and organ distribution between the first and repeated scan series were calculated via residence times. Twenty-five tumor lesions in 12 patients were visualized on both scintigraphy series. Tumor uptake decreased (19.6%; p = .03). The residence times of normal organs remained similar except for the cardiac blood pool (+ 16.3%; p = .014). Trastuzumab treatment decreases tumor 111 In-trastuzumab uptake around 20%. HER2 imaging is feasible during trastuzumab treatment.
Keywords	Biology (General) ; QH301-705.5 ; Medical technology ; R855-855.5
Language	English
Publishing date	2014-07-01T00:00:00Z
Publisher	Hindawi - SAGE Publishing
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Article ; Online: Recombinant TSH stimulated remnant ablation therapy in thyroid cancer

Anouk N A van der Horst-Schrivers / Wim J Sluiter / Anneke C Muller Kobold / Bruce H R Wolffenbuttel / John T M Plukker / Peter H Bisschop / John M de Klerk / Imad Al Younis / Paul Lips / Jan W Smit / Adrienne H Brouwers / Thera P Links

PLoS ONE, Vol 10, Iss 3, p e

the success rate depends on the definition of ablation success--an observational study.

2015 Volume 0120184

Abstract: Patients with differentiated thyroid cancer (DTC) are treated with (near)-total thyroidectomy followed by remnant ablation. Optimal radioiodine-131 (131I) uptake is achieved by withholding thyroid hormone (THW), pretreatment with recombinant human ... ...

Abstract	Patients with differentiated thyroid cancer (DTC) are treated with (near)-total thyroidectomy followed by remnant ablation. Optimal radioiodine-131 (131I) uptake is achieved by withholding thyroid hormone (THW), pretreatment with recombinant human Thyrotropin Stimulating Hormone (rhTSH) is an alternative. Six randomized trials have been published comparing THW and rhTSH, however comparison is difficult because an uniform definition of ablation success is lacking. Using a strict definition, we performed an observational study aiming to determine the efficacy of rhTSH as preparation for remnant ablation.Adult DTC patients with, tumor stage T1b to T3, Nx, N0 and N1, M0 were included in a prospective multicenter observational study with a fully sequential design, using a stopping rule. All patients received remnant ablation with 131I using rhTSH. Ablation success was defined as no visible uptake in the original thyroid bed on a rhTSH stimulated 150 MBq 131I whole body scan (WBS) 9 months after remnant ablation, or no visible uptake in the original thyroid bed on a post therapeutic WBS when a second high dose was necessary.After interim analysis of the first 8 patients, the failure rate was estimated to be 69% (90% confidence interval (CI) 20-86%) and the inclusion of new patients had to be stopped. Final analysis resulted in an ablation success in 11 out of 17 patients (65%, 95% CI 38-86%).According to this study, the efficacy of rhTSH in the preparation of 131I ablation therapy is inferior, when using a strict definition of ablation success. The current lack of agreement as to the definition of successful remnant ablation, makes comparison between different ablation strategies difficult. Our results point to the need for an international consensus on the definition of ablation success, not only in routine patient's care but also for scientific reasons.Dutch Trial Registration NTR2395.
Keywords	Medicine ; R ; Science ; Q
Subject code	616
Language	English
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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