Event-free survival after 68 Ga-PSMA-11 PET/CT in recurrent hormone-sensitive prostate cancer (HSPC) patients eligible for salvage therapy.

BACKGROUND/AIM: Prostate-specific-membrane-antigen/positron emission tomography (PSMA-PET) detects with high accuracy disease-recurrence, leading to changes in the management of biochemically-recurrent (BCR) prostate cancer (PCa). However, data regarding the oncological outcomes of patients who performed PSMA-PET are needed. The aim of this study was to evaluate the incidence of clinically relevant events during follow-up in patients who performed PSMA-PET for BCR after radical treatment. MATERIALS AND METHODS: This analysis included consecutive, hormone-sensitive, hormone-free, recurrent PCa patients (HSPC) enrolled through a prospective study. All patients were eligible for salvage therapy, having at least 24 months of follow-up after PSMA-PET. The primary endpoint was the Event-Free Survival (EFS), defined as the time between the PSMA-PET and the date of event/last follow-up. The Kaplan-Meier method was used to estimate the EFS curves. EFS was also investigated by Cox proportional hazards regression. Events were defined as death, radiological progression, or PSA recurrence after therapy. RESULTS: One-hundred and seventy-six (n = 176) patients were analyzed (median PSA 0.62 [IQR: 0.43-1.00] ng/mL; median follow-up of 35.4 [IQR: 26.5-40.3] months). The EFS was 78.8% at 1 year, 65.2% (2 years), and 52.2% (3 years). Patients experiencing events during study follow-up had a significantly higher median PSA (0.81 [IQR: 0.53-1.28] vs 0.51 [IQR: 0.36-0.80] ng/mL) and a lower PSA doubling time (PSAdt) (5.4 [IQR: 3.7-11.6] vs 12.7 [IQR: 6.6-24.3] months) (p < 0.001) compared to event-free patients. The Kaplan-Meier curves showed that PSA > 0.5 ng/mL, PSAdt ≤ 6 months, and a positive PSMA-PET result were associated with a higher event rate (p < 0.01). No significant differences of event rates were observed in patients who received changes in therapy management after PSMA-PET vs. patients who did not receive therapy changes. Finally, PSA > 0.5 ng/mL and PSAdt ≤ 6 months were statistically significant event-predictors in multivariate model (p < 0.001). CONCLUSION: Low PSA and long PSAdt were significant predictors of longer EFS. A lower incidence of events was observed in patients having negative PSMA-PET, since longer EFS was significantly more probable in case of a negative scan.

The role of PET/CT in thyroid autoimmune diseases.

Autoimmune thyroid diseases (AITD) are a heterogeneous group of disorders. They include, in particular, Graves' disease and Hashimoto's thyroiditis with a wide range of different functional status ranging from subclinical biochemical abnormalities to severe hyperthyroidism or severe hypothyroidism respectively. Furthermore, other conditions more frequently infectious or drug related can cause an immune reaction in the thyroid tissue. In AITDs, positron emission tomography/computed tomography (PET/CT) does not play a primary role for disease diagnosis or management, but accidental findings can occur in both symptomatic and asymptomatic patients, and they should be recognized and well interpreted. A comprehensive literature search of the PubMed databases was conducted to identify papers (systematic review, prospective and retrospective study, case report) evaluating the role of PET/CT in thyroid autoimmune diseases. Thyroid diffuse uptake of 18F-fluoro-2-deoxy-2-d-glucose ([18F]FDG) has been shown to be frequently associated with AITDs, but also with immune-induced thyroid disorders related to SARS-CoV-2 or immunotherapy, while malignant lesions more often have a focal aspect. Other radiopharmaceuticals as [68Ga]-DOTA-peptides, [68Ga]-fibroblast activation protein inhibitors (FAPIs) and [68Ga]-prostate specific membrane antigen ([68Ga]-PSMA) showed similar findings. In conclusion, PET/CT scan in AITDs does not play a primary role in the diagnosis, but the occasional finding of a thyroid uptake must always be described in the report and possibly investigated for a better patient's management.

Impact of radioguided occult lesion localization in the management of cervical recurrences from differentiated thyroid cancer.

BACKGROUND: Surgery is the elective treatment for cervical relapse from differentiated thyroid cancer (DTC) but it is technically challenging, with risk of failure and morbidity. We explored the feasibility and the efficacy of radioguided occult lesion localization (ROLL) with intratumoral 99mTc radiolabeled human albumin macroaggregates ([99mTc]MAA) injection in this setting. METHODS: Fifteen patients who underwent ROLL by ultrasonography (US)-guided intratumoral injection of [99mTc]MAA between December 2013 and October 2016 for DTC recurrence were considered for this study. A hand-held gamma-probe was employed for intrasurgical lesion detection. Mini-invasive ROLL-guided excision for soft tissue recurrence and ROLL-assisted modified radical neck dissection for lymph-node metastases were performed respectively. RESULTS: DTC recurrence was located in loco-regional lymph-nodes (N.=8 patients) and in thyroid bed (N.=7 patients). A total of 27 lesions was identified and injected before surgery. On a total of 124 lesions resected, histology showed 38 DTC metastases. In particular, 26 out of 27 lesions injected with [99mTc]MAA were correctly detected intra-operatively and resected without surgical complications. Ten patients received subsequent radioactive iodine (RAI) treatment to verify the complete recurrence resection. At a median follow-up of 16 months patients were classified in complete response (N.=4), biochemical incomplete response (N.=3), indeterminate response (N.=1) with no evidence of structural disease. The remaining 7 patients were classified as structural incomplete response for cervical persistent disease (N.=2), for cervical recurrence (N.=2) and for both cervical and lung metastases progression (N.=3). CONCLUSIONS: ROLL is a simple and safe procedure in the surgical management of DTC loco-regional relapse.

BSREM for Brain Metastasis Detection with 18F-FDG-PET/CT in Lung Cancer Patients.

The aim of the study was to analyze the use of block sequential regularized expectation maximization (BSREM) with different ß-values for the detection of brain metastases in digital fluorine-18 labeled 2-deoxy-2-fluoro-D-glucose (18F-FDG) PET/CT in lung cancer patients. We retrospectively analyzed staging/restaging 18F-FDG PET/CT scans of 40 consecutive lung cancer patients with new brain metastases, confirmed by MRI. PET images were reconstructed using BSREM (ß-values of 100, 200, 300, 400, 500, 600, 700) and OSEM. Two independent blinded readers (R1 and R2) evaluated each reconstruction using a 4-point scale for general image quality, noise, and lesion detectability. SUVmax of metastases, brain background, target-to-background ratio (TBR), and contrast recovery (CR) ratio were recorded for each reconstruction. Among all reconstruction techniques, differences in qualitative parameters were analyzed using non-parametric Friedman test, while differences in quantitative parameters were compared using analysis of variances for repeated measures. Cohen's kappa (k) was used to measure inter-reader agreement. The overall detectability of brain metastases was highest for BSREM200 (R1: 2.83 ± 1.17; R2: 2.68 ± 1.32) and BSREM300 (R1: 2.78 ± 1.23; R2: 2.68 ± 1.36), followed by BSREM100, which had lower accuracy owing to noise. The highest median TBR was found for BSREM100 (R1: 2.19 ± 1.05; R2: 2.42 ± 1.08), followed by BSREM200 and BSREM300. Image quality ratings were significantly different among reconstructions (p < 0.001). The median quality score was higher for BSREM100-300, and both noise and metastases' SUVmax decreased with increasing ß-value. Inter-reader agreement was particularly high for the detectability of photopenic metastases and blurring (all k > 0.65). BSREM200 and BSREM300 yielded the best results for the detection of brain metastases, surpassing both BSREM400 and OSEM, typically used in clinical practice.

RADTHYR: an open-label, single-arm, prospective multicenter phase II trial of Radium-223 for the treatment of bone metastases from radioactive iodine refractory differentiated thyroid cancer.

PURPOSE: This is the first prospective trial evaluating the efficacy of alpha emitter Radium-223 in patients with bone metastases from radioactive iodine (RAI) refractory (RAIR) differentiated thyroid cancer. METHODS: RADTHYR is a multicenter, single-arm prospective Simon two-stage phase II trial (NCT02390934). The primary objective was to establish the efficacy of three administrations of 55 kBq/kg of Radium-223 by 18F-FDG PET/CT according to PERCIST criteria. Secondary objectives were to establish the efficacy of six administrations of Radium-223 by 18F-FDG PET/CT, 99mTc-HMDP bone scan and 18FNa PET/CT, clinical benefits, changes in serum bone markers, thyroglobulin levels, and safety. RESULTS: Ten patients were enrolled between July 2015 and December 2017 (4 M; median age 74 years). Prior to Radium-223 administration, patients received a median RAI cumulative activity of 15 GBq (7.4-35.6), external radiation therapy (n = 9), bone surgery (n = 8), cimentoplasty (n = 5), and cryoablation (n = 2). 18F-FDG PET/CT showed stable disease (SD) in 4/10 and progressive disease (PD) in 6/10 cases after three administrations and SD in 4/10, PD in 5/10 cases, and 1/10 non-evaluable (NE) case after six administrations. After six injections, 99mTc-HMDP bone scan showed SD in 9 cases and was NE in 1 case; 18FNa PET/CT showed SD in 8 cases, partial response (PR) in 1 case, and was NE in 1 case. No significant clinical benefits were reported during the study. A skeletal event occurred in 6 patients (median time without skeletal event of 12.1 months). Seventy-seven adverse events were reported during treatment (7 of grade 3-4). Three patients developed an acute myeloid, a promyelocytic, and a chronic myeloid leukemia after the last Radium-223 administration considered as drug-related. CONCLUSION: The trial was stopped after interim analysis for lack of response of bone metastases from RAIR thyroid cancer to Radium-223. Severe hematological toxicity was observed in patients heavily pretreated with RAI and external radiation. TRIAL REGISTRATION NUMBER: NCT02390934. Registration date 18.03.2015.

Prevalence of interstitial pneumonia suggestive of COVID-19 at 18F-FDG PET/CT in oncological asymptomatic patients in a high prevalence country during pandemic period: a national multi-centric retrospective study.

PURPOSE: To assess the presence and pattern of incidental interstitial lung alterations suspicious of COVID-19 on fluorine-18-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) ([18F]FDG PET/CT) in asymptomatic oncological patients during the period of active COVID-19 in a country with high prevalence of the virus. METHODS: This is a multi-center retrospective observational study involving 59 Italian centers. We retrospectively reviewed the prevalence of interstitial pneumonia detected during the COVID period (between March 16 and 27, 2020) and compared to a pre-COVID period (January-February 2020) and a control time (in 2019). The diagnosis of interstitial pneumonia was done considering lung alterations of CT of PET. RESULTS: Overall, [18F]FDG PET/CT was performed on 4008 patients in the COVID period, 19,267 in the pre-COVID period, and 5513 in the control period. The rate of interstitial pneumonia suspicious for COVID-19 was significantly higher during the COVID period (7.1%) compared with that found in the pre-COVID (5.35%) and control periods (5.15%) (p < 0.001). Instead, no significant difference among pre-COVID and control periods was present. The prevalence of interstitial pneumonia detected at PET/CT was directly associated with geographic virus diffusion, with the higher rate in Northern Italy. Among 284 interstitial pneumonia detected during COVID period, 169 (59%) were FDG-avid (average SUVmax of 4.1). CONCLUSIONS: A significant increase of interstitial pneumonia incidentally detected with [18F]FDG PET/CT has been demonstrated during the COVID-19 pandemic. A majority of interstitial pneumonia were FDG-avid. Our results underlined the importance of paying attention to incidental CT findings of pneumonia detected at PET/CT, and these reports might help to recognize early COVID-19 cases guiding the subsequent management.

False negative rate at 18F-FDG PET/CT in para-aortic lymphnode involvement in patients with locally advanced cervical cancer: impact of PET technology.

BACKGROUND: The identification of factors responsible for false negative (FN) rate at 18F- Fluorodeoxyglucose (FDG) Positron Emission Tomography /Computed Tomography (PET/CT) in para-aortic (PA) lymph nodes in the presurgical staging of patients with locally advanced cervical cancer (LACC) is challenging. The aim of this study was to evaluate the impact of PET/CT technology. METHODS: A total of 240 consecutive patients with LACC (International Federation of Gynecology and Obstetrics, FIGO, stage IB2-IVA) and negative Magnetic Resonance Imaging (MRI) and/or Computed Tomography (CT) and negative 18F-FDG PET/CT in the PA region, undergoing laparoscopic PA lymphadenectomy before chemoradiotherapy were included. The FN rate in patients studied with Time of flight (TOF) PET/CT (TOF PET) or non-Time of flight PET/CT (no-TOF PET) technology was retrospectively compared. RESULTS: Patients presented with FIGO stage IB (n = 78), stage IIA-B (n = 134), stage III (n = 18) and stage IVa (n = 10), squamous cell carcinoma (n = 191) and adenocarcinoma (n = 49). 141/240 patients were evaluated with no-TOF PET/CT and 99/240 with TOF PET/CT. Twenty-two patients (9%) had PA nodal involvement at histological analysis and considered PET/CT FN findings. The FN rate was 8.5% for no-TOF PET and 10% for TOF PET subgroup respectively (p = 0.98). Ninety patients (38%) presented with pelvic node uptakes at PET/CT. The FN rate in the PA region was 18% (16/90) and 4% (6/150) in patients with and without pelvic node involvement at PET/CT respectively (19 vs 3% for no-TOF PET and 17 vs 5% for TOF PET subgroup). CONCLUSIONS: In LACC, FN rate in PA lymph nodes detection is a clinical issue even for modern PET/CT, especially in patients with pelvic uptake. Surgical lymphadenectomy should be performed in case of negative PET/CT at PA level in these patients, while it could be discussed in the absence of pelvic uptake.

Improved detection of in-transit metastases of malignant melanoma with BSREM reconstruction in digital [18F]FDG PET/CT.

OBJECTIVES: To compare block sequential regularized expectation maximization (BSREM) and ordered subset expectation maximization (OSEM) for the detection of in-transit metastasis (ITM) of malignant melanoma in digital [18F]FDG PET/CT. METHODS: We retrospectively analyzed a cohort of 100 [18F]FDG PET/CT scans of melanoma patients with ITM, performed between May 2017 and January 2020. PET images were reconstructed with both OSEM and BSREM algorithms. SUVmax, target-to-background ratio (TBR), and metabolic tumor volume (MTV) were recorded for each ITM. Differences in PET parameters were analyzed with the Wilcoxon signed-rank test. Differences in image quality for different reconstructions were tested using the Man-Whitney U test. RESULTS: BSREM reconstruction led to the detection of 287 ITM (39% more than OSEM). PET parameters of ITM were significantly different between BSREM and OSEM reconstructions (p < 0.001). SUVmax and TBR were higher (76.5% and 77.7%, respectively) and MTV lower (49.5%) on BSREM. ITM missed with OSEM had significantly lower SUVmax (mean 2.03 vs. 3.84) and TBR (mean 1.18 vs. 2.22) and higher MTV (mean 2.92 vs. 1.01) on OSEM compared to BSREM (all p < 0.001). CONCLUSIONS: BSREM detects significantly more ITM than OSEM, owing to higher SUVmax, higher TBR, and less blurring. BSREM is particularly helpful in small and less avid lesions, which are more often missed with OSEM. KEY POINTS: • In melanoma patients, [18F]FDG PET/CT helps to detect in-transit metastases (ITM), and their detection is improved by using BSREM instead of OSEM reconstruction. • BSREM is particularly useful in small lesions.

The Future of Cancer Diagnosis, Treatment and Surveillance: A Systemic Review on Immunotherapy and Immuno-PET Radiotracers.

Immunotherapy is an effective therapeutic option for several cancers. In the last years, the introduction of checkpoint inhibitors (ICIs) has shifted the therapeutic landscape in oncology and improved patient prognosis in a variety of neoplastic diseases. However, to date, the selection of the best patients eligible for these therapies, as well as the response assessment is still challenging. Patients are mainly stratified using an immunohistochemical analysis of the expression of antigens on biopsy specimens, such as PD-L1 and PD-1, on tumor cells, on peritumoral immune cells and/or in the tumor microenvironment (TME). Recently, the use and development of imaging biomarkers able to assess in-vivo cancer-related processes are becoming more important. Today, positron emission tomography (PET) with 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) is used routinely to evaluate tumor metabolism, and also to predict and monitor response to immunotherapy. Although highly sensitive, FDG-PET in general is rather unspecific. Novel radiopharmaceuticals (immuno-PET radiotracers), able to identify specific immune system targets, are under investigation in pre-clinical and clinical settings to better highlight all the mechanisms involved in immunotherapy. In this review, we will provide an overview of the main new immuno-PET radiotracers in development. We will also review the main players (immune cells, tumor cells and molecular targets) involved in immunotherapy. Furthermore, we report current applications and the evidence of using [18F]FDG PET in immunotherapy, including the use of artificial intelligence (AI).

68Ga-PSMA-11 PET/CT in recurrent hormone-sensitive prostate cancer (HSPC): a prospective single-centre study in patients eligible for salvage therapy.

OBJECTIVES: The primary objective is to assess the efficacy of 68Ga-PSMA-11-PET/CT to detect recurrent location(s) in hormone-sensitive prostate cancer (PCa). Secondary objectives are (1) to evaluate changes in clinical management; (2) to determine which covariates independently predict positive scan; (3) to assess 68Ga-PSMA-11-PET/CT performance in different settings of PSA relapse. MATERIALS AND METHODS: Inclusion criteria include (1) histologically diagnosed PCa; (2) previous radical therapy; (3) proven biochemical recurrence (BCR) or biochemical persistence (BCP); (4) hormone-sensitive PCa (HSPC); (5) androgen deprivation therapy (ADT)-free for at least 6 months; (6) PSA < 1.5 ng/mL or any PSA in case of negative choline-PET/CT (n = 38). Changes in clinical management were defined by multidisciplinary tumour-board. Clinical settings were BCP (group-1, n = 25); first-time BCR (group-2, n = 121); BCR after salvage therapy (group-3, n = 77). RESULTS: Two hundred twenty-three (223) consecutive patients were enrolled: median PSA = 0.65 ng/mL (0.2-8.9) and median PSAdt = 9.3 months (0.4-144.6). 96.9% received RP as primary therapy. 68Ga-PSMA-11-PET/CT positivity rate was 39.9% (CI95% 33.5-46.7%). Disease confined to pelvis was detected in 23.3% of cases. At least one distant lesion was observed in 16.6% of cases. Secondary objectives are as follows: (1) changes in clinical management were observed in 34.5% of patients; (2) PSA, PSAdt and T stage > 3a were independent predictors (all p < 0.03); (3) 68Ga-PSMA-11-PET/CT positivity rate was 56% (in group 1, 36.3% in group 2, 40.3% in group 3. CONCLUSION: This study attested the overall good performance of 68Ga-PSMA-11-PET/CT to detect PCa locations in HSPC patients eligible for salvage therapy, influencing the therapy management in 35.4% of cases. Furthermore, patient characteristics are influencing factors of 68Ga-PSMA-11-PET/CT positivity rate and should be considered to reduce false negative scan.

Good clinical practice recommendations for the use of PET/CT in oncology.

Positron emission tomography/computed tomography (PET/CT) is a nuclear medicine functional imaging technique with proven clinical value in oncology. PET/CT indications are continually evolving with fresh advances made through research. French practice on the use of PET in oncology was framed in recommendations based on Standards-Options-Recommendations methodology and coordinated by the French federation of Comprehensive Cancer Centres (FNLCC). The recommendations were originally issued in 2002 followed by an update in 2003, but since then, a huge number of scientific papers have been published and new tracers have been licenced for market release. The aim of this work is to bring the 2003 version recommendations up to date. For this purpose, a focus group was set up in collaboration with the French Society for Nuclear Medicine (SFMN) to work on developing good clinical practice recommendations. These good clinical practice recommendations have been awarded joint French National Heath Authority (HAS) and French Cancer Institute (INCa) label status-the stamp of methodological approval. The present document is the outcome of comprehensive literature review and rigorous appraisal by a panel of experts, organ specialists, clinical oncologists, surgeons and imaging specialists. These data were also used for the EANM referral guidelines.

Major limits of dosimetrically determined activities in advanced differentiated thyroid carcinoma.

The 2013/59 EURATOM directive defines all nuclear medicine applications for therapeutic purpose as a form of radiotherapy and underlines the need of both justification and optimization of these procedures, including radioactive iodine therapy (RAIT) with [131I] for metastatic differentiated thyroid cancer (DTC). In metastatic DTC, optimal activity to be administered to achieve the best response rate with limited toxicity is still a matter of debate and international guidelines do not provide univocal recommendations on the preferable use of empiric versus a dosimetry-based approach in these patients. The purpose of this literature review is to describe the possible limits of dosimetry in RAIT planning according to methodological aspects, tumoral heterogeneity and to report clinical data on the impact on patients' outcome of different approaches. Due to the lack of standardized dosimetry protocols and clinical data assessing the superiority of a dosimetry-based vs an empiric approach in these patients, there is a need of standardisation and prospective, properly conducted studies to validate and to assess the best approach.

Challenging pre-surgical localization of hyperfunctioning parathyroid glands in primary hyperparathyroidism: the added value of 18F-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.

Interventional locoregional treatment and metabolic response: advantages of using PET/CT in the evaluation of response to treatment.

INTRODUCTION: Interventional oncology locoregional therapies are validated treatment modalities for primary and secondary tumors in liver, lung, kidney and bone. At this time, there is no accordance in the choice of imaging modality to assess treatment response. Morphological imaging and RECIST 1.1 criteria based on size variation are limited by several critical points. On the other hand the role of functional imaging, in particular by [18F]-fluorodeoxyglucose ([18F]-FDG) positron emission tomography (PET), in both staging and response evaluation of locoregional treatments remains unclear because of the heterogeneous nature of available data. The aim of this paper was to summarize the available literature illustrating the state of art of metabolic evaluation of response after locoregional therapies in the three major organs of interest: liver, lung and bone. EVIDENCE ACQUISITION: Medline database was searched for relevant original paper evaluating the role of [18F]-FDG PET in interventional oncology treatment published up to June 2017 excluding case reports. EVIDENCE SYNTHESIS: Finally 41 studies papers evaluating the role of [18F]-FDG PET in both staging and in response evaluation of locoregional treatments focused on liver tumoral lesions (N.=29), on lung lesions (N.=10) and on bone lesions (N.=2) were considered for this review. CONCLUSIONS: PET/CT appears to perform well in the assessment of response to interventional therapies compared to conventional imaging, not only in terms of response evaluation but also as a possible prognostic tool. Nevertheless further prospective, homogenous studies are required to confirm these data, in particular for lung and bone lesions.

The intensity of 18FDG uptake does not predict tumor growth in patients with metastatic differentiated thyroid cancer.

PURPOSE: In patients with metastatic differentiated thyroid carcinoma (DTC), fluorodeoxyglucose (FDG) uptake as well as age, tumor size and radioactive iodine (RAI) uptake are prognostic factors for survival. High FDG uptake is a poor prognostic factor and lesions with high FDG uptake are often considered aggressive, but the predictive value of FDG uptake for morphological progression is unknown. The principal aim of this retrospective single center study was to determine whether the intensity of FDG uptake was correlated on a per lesion analysis with tumor growth rate (TGR) expressed as the percentage of increase in tumor size during 1 year (1-year TGR). METHODS: Fifty five patients with DTC were included between July 2012 and May 2014 with the following criteria: (i) at least one distant metastasis measuring ≥ 1 cm in diameter on CT scan (ii) evaluation by FDG-positron emission tomography/computed tomography (PET/CT) performed at our center (iii) at least one CT or another FDG-PET/CT performed 3 to 12 months after the reference FDG-PET/CT in the absence of systemic or local treatment between the two imaging procedures. RESULTS: One hundred and fifty-six metastatic lesions located in lungs (63), neck lymph nodes (28), chest lymph nodes (42), bone (11), liver (2) and other sites (12) were studied. The median size was 16 mm, median SUVmax/lesion: 8.7; median metabolic tumor volume/lesion (Metab.TV/lesion): 3.7 cm3. The median 1-year TGR was 40.68 %. SUVmax and Metab.TV/lesion were not correlated to their 1-year TGR (p = 0.38 and p = 0.74 respectively). Among single patients with multiple lesions, the lesions with the highest SUVmax/lesion or the highest Metab.TV/lesion did not disclose the higher 1-year TGR. CONCLUSION: The intensity of FDG uptake on a per lesion analysis is not correlated to its 1-year TGR and cannot be used as a surrogate marker of tumour progression.

Selumetinib-enhanced radioiodine uptake in advanced thyroid cancer.

BACKGROUND: Metastatic thyroid cancers that are refractory to radioiodine (iodine-131) are associated with a poor prognosis. In mouse models of thyroid cancer, selective mitogen-activated protein kinase (MAPK) pathway antagonists increase the expression of the sodium-iodide symporter and uptake of iodine. Their effects in humans are not known. METHODS: We conducted a study to determine whether the MAPK kinase (MEK) 1 and MEK2 inhibitor selumetinib (AZD6244, ARRY-142886) could reverse refractoriness to radioiodine in patients with metastatic thyroid cancer. After stimulation with thyrotropin alfa, dosimetry with iodine-124 positron-emission tomography (PET) was performed before and 4 weeks after treatment with selumetinib (75 mg twice daily). If the second iodine-124 PET study indicated that a dose of iodine-131 of 2000 cGy or more could be delivered to the metastatic lesion or lesions, therapeutic radioiodine was administered while the patient was receiving selumetinib. RESULTS: Of 24 patients screened for the study, 20 could be evaluated. The median age was 61 years (range, 44 to 77), and 11 patients were men. Nine patients had tumors with BRAF mutations, and 5 patients had tumors with mutations of NRAS. Selumetinib increased the uptake of iodine-124 in 12 of the 20 patients (4 of 9 patients with BRAF mutations and 5 of 5 patients with NRAS mutations). Eight of these 12 patients reached the dosimetry threshold for radioiodine therapy, including all 5 patients with NRAS mutations. Of the 8 patients treated with radioiodine, 5 had confirmed partial responses and 3 had stable disease; all patients had decreases in serum thyroglobulin levels (mean reduction, 89%). No toxic effects of grade 3 or higher attributable by the investigators to selumetinib were observed. One patient received a diagnosis of myelodysplastic syndrome more than 51 weeks after radioiodine treatment, with progression to acute leukemia. CONCLUSIONS: Selumetinib produces clinically meaningful increases in iodine uptake and retention in a subgroup of patients with thyroid cancer that is refractory to radioiodine; the effectiveness may be greater in patients with RAS-mutant disease. (Funded by the American Thyroid Association and others; ClinicalTrials.gov number, NCT00970359.).

Anatomic Variability of the Upper Mediastinal Lymph Node Level VII.

OBJECTIVE: Lymph node level VII, between the sternal notch and the innominate artery, is a frequent site of lymph node metastases in thyroid cancer. The objective of this study was to determine the cranial-caudal dimensions of level VII in patients undergoing central neck dissection for thyroid cancer and its accessibility through a neck incision only. PATIENTS AND METHODS: Consecutive patients undergoing central neck dissection for thyroid cancer, with no previous neck dissection, mediastinal or thoracic surgery. The innominate artery was identified and the distance between the sternal notch and the upper border of the artery was measured to the nearest .5 mm. The sizes of level VII were compared with respect to age, sex, height, body mass index, type of neck dissection (therapeutic or prophylactic), and the incidence of previous thyroidectomy. RESULTS: One-hundred-one consecutive patients (65 women, 36 men, mean age 44 years (range 15-87) underwent prophylactic (n = 55) or therapeutic (n = 46) bilateral central compartment neck dissection. Level VII was accessible via the horizontal neck incision in all cases. Sizes of level VII ranged from 6 cm above the sternal notch to 35 mm below the sternal notch, with a mean distance of 3.5 mm below the sternal notch. The innominate artery was at the level of the sternal notch in 29 patients, and cranial to the sternal notch in 20 cases. No statistical relationship with age, sex, therapeutic/prophylactic neck dissection, previous surgery, body mass index or height was found. CONCLUSIONS: The maximal distance below the sternal notch was 35 mm. Level VII did not exist in 49 % of patients, and was less than 25 mm caudal to the sternal notch in 95 % of cases. Distinguishing level VII from level VI in thyroid cancer surgery may not be pertinent, due to the ease of access via a classic horizontal neck incision and the small sizes of level VII in the majority of patients.