Challenging pre-surgical localization of hyperfunctioning parathyroid glands in primary hyperparathyroidism: the added value of <Superscript>18</Superscript>F-Fluorocholine PET/CT

Purpose

To evaluate the added value of ¹⁸F-Fluorocholine (¹⁸F-FCH) PET/CT in presurgical imaging of patients with primary hyperparathyroidism (HPT) and challenging localization of the hyper-functioning parathyroid glands.

Methods

We included 27 consecutive patients with primary HPT (19 F; median age: 58 years), with either (i) non-conclusive pre-surgical localization with ⁹⁹mTc-sestaMIBI scintigraphy and neck ultrasonography (US), (ii) recurrence of previously operated HPT, or (iii) familiar HPT with a suspicion of multiple gland disease. Histological findings and resolution of HPT were considered as the gold standard.

Results

¹⁸F-FCH PET/CT was positive in 24/27 patients. Twenty-one patients underwent surgery with 27 resected lesions (14 adenomas, 11 hyperplastic glands, two hyper-functioning histologically normal glands), with resolution of HPT in 19/21 patients (90%). ¹⁸F-FCH PET/CT localized 22 lesions in 17/21 patients (per patient: sensitivity 81%, positive predictive value (PPV) 94%; per gland: sensitivity 76%, PPV 85%, specificity 91%, negative predictive value (NPV) 86%). ¹⁸F-FCH PET/CT found eight lesions which were undetectable on both ⁹⁹mTc-sestaMIBI scintigraphy and US. In patients with a familial HPT and/or a multiple gland disease, sensitivity was 100 and 79% on a per-patient and a per-gland analysis respectively, while NPV was 63%. In six patients with a persistence or recurrence of previously treated HPT, ¹⁸F-FCH PET/CT localized all lesions, both in sporadic and familiar disease.

Conclusions

¹⁸F-FCH PET/CT is a promising modality in challenging pre-surgical localization of hyper-functioning parathyroid glands, such as inconclusive standard imaging, recurrence after surgery, or suspected multiple gland disease.

     

PET/CT在原发性甲状旁腺亢进症术前定位中的应用价值及其术前定位影像学新进展

原发性甲状旁腺功能亢进症(PHPT)是一种常见的内分泌疾病,通常由甲状旁腺功能亢进引起。手术切除功能亢进的病灶是治疗PHPT的主要手段,正确定位病灶对于指导PHPT患者的微创手术治疗至关重要。PET/CT目前已经成为甲状旁腺腺瘤术前定位的一线影像学手段,而如何从血清生化水平筛选出适合行PET/CT的患者成为临床应用的重点,从组织病理学和免疫组化水平分析其与PET相关参数的关系也是目前研究的热点。笔者主要就PHPT患者的血清生化水平、组织病理学信息、免疫组化与PET/CT相关参数之间的关系进行分析,并介绍了PHPT术前定位的影像学新进展,以期为PET/CT的临床应用提供指导。     

Preoperative F-18 fluorocholine PET/CT for the detection of hyperfunctioning parathyroid glands in patients with secondary or tertiary hyperparathyroidism: comparison with Tc-99m sestamibi scan and neck ultrasound

Annals of Nuclear Medicine - Currently, neck ultrasound is the preferred preoperative imaging in patients with secondary/tertiary hyperparathyroidism, and the use of Tc-99m sestamibi scan is...     

四维CT对原发性甲状旁腺机能亢进病人的异常甲状旁腺定位的准确性研究

摘要目的探讨多期多排探测器四维CT技术对于原发性甲状旁腺机能亢进病人异常甲状旁腺定位的准确性。材料与方法本回顾性图表复习研究通过伦理审查委员会审核,无需知情同意。     

F18-choline PET/CT guided surgery in primary hyperparathyroidism when ultrasound and MIBI SPECT/CT are negative or inconclusive: the APACH1 study

Purpose

To evaluate the sensitivity of F18-choline (FCH) PET/CT for parathyroid adenoma detection prior to surgery in patients with primary hyperparathyroidism and negative or inconclusive cervical ultrasound and Tc99m-sestaMIBI SPECT/CT.

Methods

We conducted a prospective bicentric study (NCT02432599). All patients underwent FCH PET/CT. The result was scored positive, inconclusive or negative. The number of uptakes and their sites were recorded. The FCH PET/CT result guided the surgical procedure (minimally invasive parathyroidectomy, bilateral cervical exploration, or other in case of multiple or ectopic foci). FCH PET/CT results were compared to the surgical and pathological findings and the follow-up.

Results

Twenty-five patients were included. Mean calcium and PTH levels prior to surgery were 2.76?±?0.17 mmol/l and 94.8?±?37.4 ng/l. Nineteen (76%) FCH PET/CTs were scored positive, 3 (12%) inconclusive and 3 (12%) negative, showing 21 cases of uniglandular disease, including 1 ectopic localization and 1 case of multiglandular (3 foci) disease. Mean lesion size was 13.1?±?8.6 mm. Twenty-four patients underwent surgery. FCH PET/CT guided surgery in 22 (88%) patients, allowing for 17 minimally invasive parathyroidectomies, 1 bilateral cervical exploration for multifocality and 4 other surgical procedures. Two patients with negative FCH-PET/CT underwent bilateral cervical exploration. When dichotomizing the FCH PET/CT results, thereby classifying the inconclusive FCH PET/CT results as positive, the per lesion and per patient sensitivities were 91.3% (95%CI: 72.0–98.9) and 90.5% (95%CI: 69.6–98.8) and the corresponding positive predictive values were 87.5% (95%CI: 67.6–97.3) and 86.4% (95%CI: 65.1–97.1), respectively.Twenty-one (88%) patients were considered cured after surgery. Their mean calcium level after surgery was 2.36?±?0.17 mmol/l.

Conclusions

Preoperative FCH PET/CT has a high sensitivity and positive predictive value for parathyroid adenoma detection in patients with primary hyperparathyroidism and negative or inconclusive conventional imaging results. Bilateral cervical exploration could be avoided in the majority (75%) of patients.

     

18F-fluorocholine versus 18F-fluorodeoxyglucose for PET/CT imaging in patients with suspected relapsing or progressive multiple myeloma: a pilot study

Purpose

Hybrid positron emission tomography/computed tomography (PET/CT) has now become available, as well as whole-body, low-dose multidetector row computed tomography (MDCT) or magnetic resonance imaging (MRI). The radioactive glucose analogue 18F-fluorodeoxyglucose (FDG) is the most widely used tracer but has a relatively low sensitivity in detecting multiple myeloma (MM). We compared FDG with a more recent metabolic tracer, 18F-fluorocholine (FCH), for the detection of MM lesions at time of disease relapse or progression.

Methods

We analyzed the results of FDG and FCH imaging in 21 MM patients undergoing PET/CT for suspected relapsing or progressive MM. For each patient and each tracer, an on-site reader and a masked reader independently determined the number of intraosseous and extraosseous foci of tracer and the intensity of uptake as measured by their SUVmax and the corresponding target/non-target ratio (T/NT).

Results

In the skeleton of 21 patients, no foci were found for two cases, uncountable foci were observed in four patients, including some mismatched FCH/FDG foci. In the 15 patients with countable bone foci, the on-site reader detected 72 FDG foci vs. 127 FCH foci (+76 %), whereas the masked reader detected 69 FDG foci vs. 121 FCH foci (+75 %), both differences being significant. Interobserver agreement on the total number of bone foci was very high, with a kappa coefficient of 0.81 for FDG and 0.89 for FCH. Measurement of uptake in the matched foci that took up both tracers revealed a significantly higher median SUVmax and T/NT for FCH vs. FDG. Almost all unmatched foci were FCH-positive FDG-negative (57/59?=?97 % on-site and 56/60?=?93 % on masked reading); they were more frequently observed than matched foci in the head and neck region.

Conclusions

These findings suggest that PET/CT performed for suspected relapsing or progressive MM would reveal more lesions when using FCH rather than FDG.

     

原发性肺黏膜相关淋巴组织淋巴瘤的18F-FDG PET/CT影像学表现

目的 分析原发性肺黏膜相关淋巴组织（MALT）淋巴瘤的18F-FDG PET/CT影像学表现,提高对原发性肺MALT淋巴瘤的认识及诊断能力。 方法 回顾性分析2006年11月至2017年4月经病理确诊的9例原发性肺MALT淋巴瘤患者（男性6例、女性3例,中位年龄59岁）的临床资料及18F-FDG PET/CT显像资料,记录病灶的部位、数量、密度、大小、形态及最大标准化摄取值（SUV_max）,以及纵隔及肺门淋巴结等情况;分析影像信息并同时进行相关文献复习。 结果 9例原发性肺MALT淋巴瘤患者18F-FDG PET/CT表现分为3型:实变型4例、肿块型3例、弥漫肺炎型2例。实变型表现为大小、受累范围不等的实变影;肿块型表现为单发或多发、边缘毛糙的实性肿块影;弥漫肺炎型表现为肺叶内或双肺弥漫的斑片、团块样软组织密度影。在9例患者中可见支气管充气征8例（部分伴有支气管扩张）、三角型灌注征3例、病灶向中心聚拢4例、钙化2例、胸腔积液2例、肺门及纵隔淋巴结肿大2例。所有病灶18F-FDG 代谢不均匀增高,中位SUV_max为6.0（2.6~8.3）;2例弥漫肺炎型纵隔及肺门淋巴结18F-FDG摄取异常增高,SUV_max分别为13.0、4.7。 结论 原发性肺MALT淋巴瘤的18F-FDG PET/CT表现常为斑片状致密影,多见实变影,内部常见支气管充气征,18F-FDG轻度摄取,结合相对缓慢的病程,可考虑为原发性肺MALT淋巴瘤。     

PET with [18F]fluorothymidine for imaging of primary breast cancer: a pilot study

The aim of this study was to evaluate the use of [¹⁸F]fluorothymidine (FLT) as a positron emission tomography (PET) tracer for the diagnosis of breast cancer. To this end, 12 patients with 14 primary breast cancer lesions (T2–T4) were studied by FLT-PET. For comparison, [¹⁸F]fluorodeoxyglucose (FDG) PET scans were performed in six patients. Thirteen of the 14 primary tumours demonstrated focally increased FLT uptake (SUV_mean=3.4±1.1). Seven out of eight patients with histologically proven axillary lymph node metastases showed focally increased FLT uptake in the corresponding areas (SUV_mean=2.4±1.2). The lowest SUV (mean =0.7) was observed in one of two inflammatory cancers. The contrast between primary tumours or metastases and surrounding tissue was high in most cases. In direct comparison to FDG-PET, the SUVs of primary tumours (5/6) and axillary lymph node metastases (3/4) were lower in FLT-PET (SUV_FLT: 3.2 vs SUV_FDG: 4.7 in primary tumours and SUV_FLT: 2.9 vs SUV_FDG: 4.6 in lymph node metastases). Since FLT uptake in surrounding breast tissue was also lower, tumour contrast was comparable to that with FDG. It is of note that normal FLT uptake was very low in the mediastinum, resulting in a higher tumour-to-mediastinum ratio as compared to FDG (P=0.03). FLT-PET is suitable for the diagnosis of primary breast cancer and locoregional metastases. High image contrast may facilitate the detection of small foci, especially in the mediastinum.     

Arterial and fat tissue inflammation are highly correlated : a prospective 18F-FDG PET/CT study

Purpose

There is evidence that the link between obesity and cardiovascular disease might relate to inflammation in both fat tissue and the arterial wall. ¹⁸F-FDG uptake on PET is a surrogate marker of vessel wall inflammation. The aim of the study was to measure FDG uptake in both regions using PET and identify links between adipose and arterial inflammation.

Methods

Included in the study were 173 cardiovascular patients who were prospectively imaged with FDG PET/CT. Arterial FDG uptake was measured in the carotid arteries and ascending aorta. The same was done in fat tissue in the neck, the presternal region (both subcutaneous) and the pericardium. FDG uptake was quantified as average maximal target-to-background ratio (_meanTBR_max). Multivariate regression analyses were performed to identify significant associations between arterial and adipose tissue FDG uptake and clinical variables as given by the standardized correlation coefficient (β).

Results

FDG uptake values in all fat tissue regions were highly predictive of vascular FDG uptake in both the carotids (β 0.262, p?<?0.0001, in the neck subcutaneous region) and aorta (β 0.22, p?=?0.008, in the chest pericardial region; β 0.193, p?=?0.019, in the chest subcutaneous region). Obesity was significantly associated with elevated FDG uptake in adipose tissue (β 0.470, p?<?0.0001, in the neck subcutaneous region; β 0.619, p?=?0.028, in the chest subcutaneous region; β 0.978, p?=?0.035, in the chest pericardial region).

Conclusion

FDG uptake in diverse fat tissue regions was significantly associated with arterial FDG uptake, a reasonable surrogate of inflammation. Increasing body weight significantly predicted the level of fatty inflammation. FDG PET therefore provides imaging evidence of an inflammatory link between fat tissue and the vasculature in patients with cardiovascular disease.     

Diagnostic performance of 18F-fluorothymidine PET/CT for primary colorectal cancer and its lymph node metastasis: comparison with 18F-fluorodeoxyglucose PET/CT

Purpose

To examine the diagnostic performance of ¹⁸F-fluorothymidine (FLT) PET/CT in primary and metastatic lymph node colorectal cancer foci in comparison with ¹⁸F-fluorodeoxyglucose (FDG) PET/CT.

Methods

The study population comprised 28 patients with 30 newly diagnosed colorectal cancers who underwent surgical resection of the primary lesion and regional lymph nodes after both FLT and FDG PET/CT. The associations between SUVmax levels and pathological factors were evaluated using the Mann-Whitney U or Kruskal-Wallis test. Differences in diagnostic indexes for detecting nodal metastasis between the two tracers were estimated using the McNemar exact or χ ² test.

Results

All 30 primary cancers (43.0?±?20.0 mm, range 14 – 85 mm) were visualized by both tracers, but none of the FLT SUVmax values exceeded the FDG SUVmax values in any of the primary cancers (6.6?±?2.4 vs. 13.6?±?5.8, p?<?0.001). The sensitivity, specificity and accuracy for detecting nodal metastasis were 41 % (15/37), 98.8 % (493/499) and 94.8 % (508/536) for FDG PET/CT, and 32 % (12/37), 98.8 % (493/499) and 94.2 % (505/536) for FLT PET/CT, respectively. The sensitivity (p?=?0.45), specificity (p?=?0.68) and accuracy (p?=?0.58) were not different between the tracers. Nodal uptake of FLT and FDG was discordant in 7 (19 %) of 37 metastatic nodes. There were ten concordant true-positive nodes of which six showed higher FDG SUVmax and four showed higher FLT SUVmax, but the difference between FDG and FLT SUVmax was not significant (5.56?±?3.55 and 3.62?±?1.45, respectively; p?=?0.22).

Conclusion

FLT has the same potential as FDG in PET/CT for the diagnosis of primary and nodal foci of colorectal cancer despite significantly lower FLT uptake in primary foci.     

Comparison of 18F-fluoride PET/CT, 18F-FDG PET/CT and bone scintigraphy (planar and SPECT) in detection of bone metastases of differentiated thyroid cancer: a pilot study

Objective:

We compared the efficacies of ¹⁸F-fluoride positron emission tomography (¹⁸F-fluoride PET)/CT, ¹⁸F-fludeoxyglucose PET (¹⁸F-FDG PET)/CT, and ^99mTc bone scintigraphy [planar and single photon emission CT (SPECT)] for the detection of bone metastases in patients with differentiated thyroid carcinoma (DTC).

Methods:

We examined 11 patients (8 females and 3 males; mean age ± standard deviation, 61.9 ± 8.7 years) with DTC who had been suspected of having bone metastases after total thyroidectomy and were hospitalized to be given ¹³¹I therapy. Bone metastases were verified either when positive findings were obtained on both ¹³¹I scintigraphy and CT or when MRI findings were positive if MRI was performed.

Results:

Metastases were confirmed in 24 (13.6%) of 176 bone segments in 9 (81.8%) of the 11 patients. The sensitivities of ¹⁸F-fluoride PET/CT and ^99mTc bone scintigraphy (SPECT) were significantly higher than those of ¹⁸F-FDG PET/CT and ^99mTc bone scintigraphy (planar) (p < 0.05). The accuracies of ¹⁸F-fluoride PET/CT and ^99mTc bone scintigraphy (SPECT) were significantly higher than that of ^99mTc bone scintigraphy (planar) (p < 0.05).

Conclusion:

The sensitivity and accuracy of ¹⁸F-fluoride PET/CT for the detection of bone metastases of DTC are significantly higher than those of ^99mTc bone scintigraphy (planar). However, the sensitivity and accuracy of ^99mTc bone scintigraphy (planar) are improved near to those of ¹⁸F-fluoride PET/CT when SPECT is added to a planar scan. The sensitivity of ¹⁸F-FDG PET/CT is significantly lower than that of ¹⁸F-fluoride PET/CT or ^99mTc bone scintigraphy (SPECT).

Advances in knowledge:

This article has demonstrated first the high efficacy of ¹⁸F-fluoride PET/CT for the detection of bone metastases of DTC.Differentiated thyroid carcinoma (DTC) shows a relatively good prognosis compared with carcinomas of other organs, and the 10-year survival rate of DTC is >80% because of treatments such as total thyroidectomy and ablation of remnants with radioiodine.¹ However, metastases of DTC develop in 7–23% of patients; the distant metastases occur commonly in the lungs, bones and brain, and the bones are the second most common site of metastases of DTC.² Bone scintigraphy using ^99mTc-labelled phosphate compounds [^99mTc-methylene diphosphonate (^99mTc-MDP) or ^99mTc-hydroxymethylene diphosphonate (^99mTc-HMDP)] has been widely used for detecting and evaluating bone metastases of various kinds of carcinomas because of its overall high sensitivity and the easy evaluation of the entire skeleton.³ However, there were often false-positive cases in ^99mTc bone scintigraphy, because degenerative or inflammatory foci were often confused with metastatic lesions. The addition of single photon emission CT (SPECT) to planar acquisition of ^99mTc bone scintigraphy has been shown to exhibit a beneficial effect on the detection and evaluation of bone metastases.^4–6 Skeletal imaging by ¹⁸F-fludeoxyglucose positron emission tomography (¹⁸F-FDG PET)/CT has been shown to be useful in the detection of bone metastases of various carcinomas including DTC.⁷Previously, we compared the efficacies of ¹⁸F-FDG PET and planar ^99mTc bone scintigraphy for the detection of bone metastases in patients with DTC.⁸ We found that the specificity and the overall accuracy of ¹⁸F-FDG PET for the detection of bone metastases in patients with DTC were higher than those of planar ^99mTc bone scintigraphy, whereas the difference in the sensitivity of both examinations was not statistically significant, and concluded that ¹⁸F-FDG PET is superior to planar ^99mTc bone scintigraphy because of its lower incidence of false-positive results in the detection of bone metastases of DTC.⁸¹⁸F-fluoride is a positron-emitting bone-seeking radiotracer, which has a similar uptake mechanism to ^99mTc-MDP and ^99mTc-HMDP. As the availability of PET systems was increasing, ¹⁸F-fluoride has been used for skeletal PET imaging since 1990s. PET or PET/CT with ¹⁸F-fluoride have been shown to be more sensitive than planar ^99mTc bone scintigraphy for the detection of bone metastases of lung,⁹ breast,^10,11 hepatocellular,¹² prostate,^11,13,14 colon and bladder¹¹ cancers. However, to the best of our knowledge, there have been no systematic comparative studies on the efficacies of ¹⁸F-fluoride PET/CT, ¹⁸F-FDG PET/CT and ^99mTc bone scintigraphy (planar and SPECT) for the detection of bone metastases of DTC. This study was conducted to compare ¹⁸F-fluoride PET/CT, ¹⁸F-FDG PET/CT and ^99mTc bone scintigraphy (planar and SPECT) in the detection of bone metastases of DTC.