Increase of prostate-specific antigen doubling time predicts survival in metastatic castration-resistant prostate cancer patients undergoing radium therapy.

OBJECTIVE: Radium-223 (Ra-223) is an important treatment modality for bone-dominant metastatic castration-resistant prostate cancer (mCRPC). However, there is currently a lack of effective markers to monitor treatment response during treatment. We aim to investigate the response in prostate-specific antigen doubling time (PSADT) as a potential marker for assessing Ra-223 treatment in mCRPC patients. METHODS: We retrospectively collected data from mCRPC patients who underwent radium treatment at our institution between August 2020 and June 2023. Prostate-specific antigen (PSA) measurements prior to treatment and during treatment were collected. Baseline PSADT was calculated from PSA measurements prior to Ra-223 treatment; interim PSADT was calculated from PSA measurements before Ra-223 treatment and prior to the fourth course injection. Overall survival was calculated from the start of treatment to the date of death. Univariable and multivariable analysis using the Cox proportional hazards model were performed to examine the association of factors with overall survival. RESULTS: We included 35 patients from our institution, with a median overall survival of 13.3 months. Eighteen (51.4%) completed all six courses of treatment. PSA dynamic response (interim PSADT > baseline PSADT or decreased PSA) was observed in 20 patients. Overall survival was associated with a PSA dynamic response (HR = 0.318, 95% CI 0.133-0.762, p = 0.010) when compared to patients without response. CONCLUSIONS: Dynamic changes in PSADT were associated with survival in mCRPC patients receiving radium therapy. Comparing interim and baseline PSADT could serve as a valuable marker for determining treatment benefits.

FDG PET/CT and Endoscopic Ultrasound for Preoperative T-Staging of Esophageal Squamous Cell Carcinoma.

This study aimed to compare the diagnostic performances of endoscopic ultrasound (EUS) and FDG PET/CT in the preoperative T-staging of esophageal squamous cell carcinoma (ESCC) and determine whether their innovative coordination achieves better prediction. In total, 100 patients diagnosed with ESCC, 57 without (CRT[-]sub) and 43 with (CRT[+]sub) neoadjuvant chemoradiotherapy, undergoing EUS and FDG PET/CT, followed by surgical resection of the tumor, were included in this analysis. EUS classified T-stages based on the depth of primary tumor invasion, and FDG PET/CT used thresholded maximal standardized uptake value (SUVmax) classifications. By employing pathology results as the reference standard, we assessed the accuracy of EUS and FDG PET/CT, evaluated their concordance using the κ statistic, and conducted a comparative analysis between the two modalities through McNemar's chi-square test. FDG PET/CT had higher overall accuracy than EUS (for CRT[-]sub: 71.9%, κ = 0.56 vs. 56.1%, κ = 0.31, p = 0.06; for CRT[+]sub: 65.1%, κ = 0.50 vs. 18.6%, κ = 0.05, p < 0.01) in predicting pT- and ypT-stage. Our proposed method of incorporating both FDG PET/CT and EUS information could achieve higher accuracies in differentiating between early and locally advanced disease in the CRT[-]sub group (82.5%) and determining residual viable tumor in the CRT[+]sub group (83.7%) than FDG PET/CT or EUS alone. FDG PET/CT had a better diagnostic ability than EUS to predict the (y)pT-stage of ESCC. Our complementary method, which combines the advantages of both imaging modalities, can deliver higher accuracy for clinical applications of ESCC.

Social cognitive deficit is associated with visuomotor coordination impairment and dopamine transporter availability in euthymic bipolar disorder.

BACKGROUND: Extensive evidence has suggested functional connections between co-occurring visuomotor and social cognitive deficits in neuropsychiatric disorders; however, such association has not been studied in bipolar disorder (BD). We aimed to investigate the relationship between visuomotor coordination and social cognition in the euthymic stage of BD (euBD). Given the shared neurobiological underpinnings involving the dopaminergic system and corticostriatal circuitry, we hypothesized a positive correlation between social cognition and visuomotor coordination in euBD patients. METHODS: 40 euBD patients and 59 healthy control (HC) participants underwent evaluation of social (Diagnostic Analysis of Nonverbal Accuracy 2-Taiwan version (DANVA-2-TW)), non-social cognitive function and visuomotor coordination. A subgroup of participants completed single-photon emission computed tomography for striatal dopamine transporter (DAT) availability assessment. RESULTS: EuBD patients showed impaired nonverbal emotion recognition (ps ≤ 0.033) and poorer visuomotor coordination (ps < 0.003) compared to HC, with a positive correlation between these two abilities (r = 0.55, p < 0.01). However, after considering potential confounding factors, instead of visuomotor coordination, striatal DAT availability was a unique predictor of emotion recognition accuracy in euBD (beta = 0.33, p = 0.001). CONCLUSION: Our study result supported a functional association between social cognition and visuomotor coordination in euBD, with striatal dopaminergic dysfunction emerged as a crucial contributing factor in their interrelation.

Dual-Time-Point 18 F-FDG PET/CT for Differentiating a Chest Wall Hemangioma From a Malignant Metastasis.

ABSTRACT: Dual-time-point 18 F-flluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) can be used to differentiate benign vascular tumors from other malignant growths. We present the case of a 70-year-old woman with a history of cervical carcinoma who was referred for PET/CT to examine a left chest wall tumor noted on CT, which involved the adjacent rib and pleura, thus raising the suspicion of metastasis. The chest wall tumor demonstrated moderate FDG uptake and further decreased uptake at the delayed-phase scanning, corresponding to biodistribution of FDG in the blood pool. These findings indicated a benign hemangioma rather than a metastasis.

Early post-treatment 18F-FDG PET/CT for predicting radiation-induced hypothyroidism in head and neck cancer.

BACKGROUND: Radiation-induced hypothyroidism (RIHT) is a common, but underestimated, late adverse effect in head and neck cancer. We investigated the value of early post-treatment 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for predicting RIHT. METHODS: We searched our institutional database for patients aged ≥ 20 years who had undergone definitive radiotherapy for nasopharyngeal or oropharyngeal cancer between 2005 and 2017, followed by 18F-FDG PET/CT within 180 days of radiotherapy completion. We visually assessed and compared PET/CT and baseline characteristics in patients with and without RIHT using the chi-square test for categorical variables and the t-test for continuous variables. Variable predictive ability was evaluated by measuring the area under receiver operating characteristic curves. RESULTS: Fifty-two patients were included; 22 (42%) developed RIHT and 30 (58%) did not. Two patients presented with diffuse thyroid uptake on PET/CT via visual assessment, and both developed RIHT later. Among the PET/CT variables, thyroid functioning volume was significantly higher in patients without RIHT than in patients with RIHT (16.30 ± 6.03 cm3 vs. 10.61 ± 3.81 cm3, p < 0.001). The maximum standard uptake values of the thyroid and pituitary glands did not differ significantly between the groups. Two patient characteristics, pretreatment thyroid volume and mean radiotherapy dose to the thyroid, also showed significant differences between the groups. An algorithmic approach combining visual grading of thyroid 18F-FDG uptake and thyroid functioning volume cutoff of 14.01 yielded an area under curve of 0.89 (95% confidence interval, 0.80-0.98); the sensitivity, specificity, positive predictive value, and negative predictive value were 87.0%, 82.3%, 80.0%, and 88.9%, respectively. CONCLUSION: Early post-treatment PET/CT-derived thyroid functioning volume was a good predictor of RIHT development. Diffusely increased thyroid 18F-FDG uptake on PET/CT may indicate impending RIHT. Routine surveillance of thyroid function is warranted in patients at high risk of developing RIHT.

Striatal Dopamine Transporter Availability is Associated with Sleep Disturbance among Patients with Bipolar I Disorder: A Single-photon Emission Computed Tomography Study Using [99mTc] TRODAT-1.

Objective: Bipolar disorder (BD) is characterized by the poor sleep quality. Whether the striatal dopamine transporter (DAT) availability is related to sleep quality among patients with BD is unclear. Methods: Fifty-three euthymic patients with BD (24 BD-I and 29 BD-II) and sixty-eight healthy controls were enrolled. The Chinese Version of the Pittsburgh Sleep Quality Index (PSQI) was used, and the availability of DAT was assessed by single-photon emission computed tomography (SPECT) using [99mTc] TRODAT-1. Results: The sleep disturbance component of the PSQI was significantly associated with the level of DAT availability among patients with BD. Conclusion: The striatal dopaminergic activity that contributes to resilience to adversity was associated with sleep pattern among patients with BD.

Serotonin Modulates the Correlations between Obsessive-compulsive Trait and Heart Rate Variability in Normal Healthy Subjects: A SPECT Study with [123I]ADAM and Heart Rate Variability Measurement.

Objective: The impact of serotonergic system on obsessive-compulsive disorder (OCD) is well studied. However, the correlation between OC presentations and autonomic nervous system (ANS) is still unclear. Furthermore, whether the correlation might be modulated by serotonin is also uncertain. Methods: We recruited eighty-nine healthy subjects. Serotonin transporter (SERT) availability by [123I]ADAM and heart rate variability (HRV) tests were measured. Symptoms checklist-90 was measured for the OC presentations. The interaction between HRV and SERT availability were calculated and the correlation between HRV and OC symptoms were analyzed after stratified SERT level into two groups, split at medium. Results: The interactions were significant in the factors of low frequency (LF), high frequency (HF), and root mean square of successive differences (RMSSD). Furthermore, the significantly negative correlations between OC symptoms and the above HRV indexes existed only in subjects with higher SERT availability. Conclusion: OC symptoms might be correlated with ANS regulations in subjects with higher SERT availability.

Measuring distance from the incisors to the esophageal cancer by FDG PET/CT: endoscopy as the reference.

BACKGROUND: Using endoscopy as the reference, this study evaluated the accuracy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in measuring distance from the incisors to the PET detectable esophageal cancer. If there is high concordance between endoscopic and PET measurements, our results may provide a basis to use FDG PET/CT in cooperation with endoscopic measurement to localize those PET/CT and CT undetectable esophageal tumors for radiotherapy planning. MATERIALS: Esophageal cancer patients with pretreatment endoscopy and FDG PET/CT detectable esophageal tumors were recruited retrospectively. The distances from the incisors to the proximal esophageal tumor margins were determined by endoscopy and by the sagittal images of FDG PET/CT. The endoscopic measurement was used as the comparative reference. A nuclear medicine doctor and a radiation oncologist each performed the FDG PET/CT measurement twice for every patient. We analyzed the differences in these measurements, and assessed agreement and reproducibility of the results by the intraclass correlation coefficient (ICC). RESULTS: Thirty-four patients, with 35 esophageal tumors, were included. By endoscopy and FDG PET/CT, the mean distances from the incisors to the proximal esophageal tumor margin were 27.3 ± 6.4 cm (range 17.1-40.0 cm) and 26.8 ± 6.3 cm (range 15.7-41.3 cm), respectively. The mean absolute differences between the endoscopic and four FDG PET/CT measurements ranged from 1.129 to 1.289 cm (SD: 0.98-1.19). The measurement agreement between FDG PET/CT and endoscopy by ICC was between 0.962 and 0.971. The intra- and interobserver reproducibilities of the two readers were excellent (intraobserver ICC: 0.985, 0.996; interobserver ICC: 0.976-0.984). CONCLUSIONS: FDG PET/CT was in high agreement with endoscopy in measuring the distance from the incisors to the proximal esophageal tumor margin. For FDG PET/CT and CT undetectable esophageal cancer, incorporation of the endoscopic measurement with PET/CT might be a way for making radiotherapy plan.

Striatal dopamine D2/3 receptors in medication-naïve schizophrenia: an [123I] IBZM SPECT study.

BACKGROUND: The hyper-function of the striatal dopamine system has been suggested to underlie key pathophysiological mechanisms in schizophrenia. Moreover, patients have been observed to present a significant elevation of dopamine receptor availability compared to healthy controls. Although it is difficult to measure dopamine levels directly in humans, neurochemical imaging techniques such as single-photon emission computed tomography (SPECT) provide indirect indices of in vivo dopamine synthesis and release, and putative synaptic levels. METHODS: We focused on the role of dopamine postsynaptic regulation using [123I] iodobenzamide (IBZM) SPECT. We compared D2/3 receptor availability between 53 healthy controls and 21 medication-naive patients with recent-onset schizophrenia. RESULT: The mean specific striatal binding showed no significant difference between patients and controls (estimated difference = 0.001; 95% CI -0.11 to 0.11; F = 0.00, df = 1, 69; p = 0.99). There was a highly significant effect of age whereby IBZM binding declined with advancing age [estimated change per decade of age = -0.01(binding ratio); 95% CI -0.01 to -0.004; F = 11.5, df = 1, 69; p = 0.001]. No significant correlations were found between the mean specific striatal binding and psychopathological or cognitive rating scores. CONCLUSIONS: Medication-naïve patients with recent-onset schizophrenia have similar D2/3 receptor availability to healthy controls. We suggest that, rather than focusing exclusively on postsynaptic receptors, future treatments should target the presynaptic control of dopamine synthesis and release.

Anaplastic Thyroid Cancer Successfully Treated With Radiation and Immunotherapy: A Case Report.

OBJECTIVE: Anaplastic thyroid cancer (ATC) is a rare thyroid cancer subtype with a devastating prognosis. Novel treatment strategies are under investigation to improve the survival of patients with ATC. METHODS: We present a case of recurrent ATC treated with a combination of radiation therapy (RT) and pembrolizumab, a programmed death-1 inhibitor, with a durable complete response. RESULTS: A 63-year-old woman underwent total thyroidectomy and left neck lymph node dissection and was diagnosed with papillary carcinoma in December, 2017. She received radioiodine in April, 2018. However, a left neck mass was noted in April, 2018 with biopsy demonstrating ATC with 95% positivity for programmed death-ligand 1 immunostaining. Positron emission tomography showed fluorodeoxyglucose uptake in the left thyroid bed and multiple lymph nodes in the left retropharyngeal, left neck, and right upper paratracheal areas. Hypofractionated RT for the recurrent areas was initiated in August,2018, and concomitant pembrolizumab was given 2 days after RT. A total of 10 cycles of pembrolizumab (2 mg/kg) were given every 3 weeks. The computed tomography scan after completion of RT and 3 cycles of pembrolizumab showed shrinkage of the neck lymph nodes. The serial follow-up computed tomography scans showed further shrinkage of the lymph nodes, and there was no recurrence of ATC as of October, 2020. CONCLUSION: We describe an ATC case successfully treated with a combination of RT and pembrolizumab with a durable response of 26 months and acceptable toxicities. This result warrants further investigation of this combination regimen in the treatment of ATC.

The feasibility of anterior 180° 99m Tc-sestamibi parathyroid SPECT/CT.

OBJECTIVE: For 99mTc-sestamibi parathyroid single photon emission computed tomography/computed tomography (SPECT/CT), the traditional full-arc 360° acquisition technique has been suggested but not the theoretically low tissue-attenuated anterior 180° method. We aimed to compare the diagnostic performances and target-to-background ratios of anterior 180° and 360° SPECT/CT imaging. METHODS: Ninety-nine patients who underwent 99mTc-sestamibi scintigraphy and received a surgical-pathological diagnosis of parathyroid adenoma or hyperplasia were enrolled. The SPECT/CT reconstructed images with anterior 180° and full-arc 360° data were interpreted by two physicians using a scoring scale, and the lesions were semi-quantified using target-to-background ratios for both image sets. RESULTS: In total, 113 abnormal parathyroid lesions were identified on the SPECT/CT images. The agreements of interpretation between the two image sets and readers were very good (κ value: 0.83-1.00). The accuracies of summative interpretation for the anterior 180° and full-arc 360° SPECT/CT were 83.04% and 82.46%, respectively. The target-to-background ratios were significantly higher for the anterior 180° than the full-arc 360° images (P < 0.01). CONCLUSIONS: The anterior 180° SPECT/CT technique, a time-saving method, can provide satisfactory diagnostic performance and superior lesion contrast compared with the full-arc 360° SPECT/CT technique in 99mTc-sestamibi parathyroid imaging.

Changes in striatal dopamine transporters in bipolar disorder and valproate treatment.

BACKGROUND: Previous studies suggested that a disturbance of the dopamine system underlies the pathophysiology of bipolar disorder (BD). In addition, the therapeutic action of medications for treating BD, such as valproate (VPA), might modulate dopamine system activity, but it remains unclear. Here, we aimed to investigate the role of the striatal dopamine transporter (DAT) in BD patients and in social defeat (SD) mice treated with VPA. METHODS: We enrolled community-dwelling controls (N = 18) and BD patients (N = 23) who were treated with VPA in a euthymic stage. The striatal DAT availabilities were approached by TRODAT-1 single photon emission computed tomography. We also established a chronic SD mouse model and treated mice with 350 mg/kg VPA for 3 weeks. Behavioral tests were administered, and striatal DAT expression levels were determined. RESULTS: In humans, the level of striatal DAT availability was significantly higher in euthymic BD patients (1.52 ± 0.17 and 1.37 ± 0.23, p = 0.015). Moreover, the level of striatal DAT availability was also negatively correlated with the VPA concentration in BD patients (r = -0.653, p = 0.003). In SD mice, the expression of striatal DAT significantly increased (p < 0.001), and the SD effect on DAT expression was rescued by VPA treatment. CONCLUSIONS: The striatal DAT might play a role in the pathophysiology of BD and in the therapeutic mechanism of VPA. The homeostasis of DAT might represent a new therapeutic strategy for BD patients.

A pilot study on the association between the blood oxygen level-dependent signal in the reward system and dopamine transporter availability in adults with attention deficit hyperactivity disorder.

BACKGROUND: It is well-known that attention deficit hyperactivity disorder (ADHD) is associated with changes in the dopaminergic system. However, the relationship between central dopaminergic tone and the blood oxygen level-dependent (BOLD) signal during receipt of rewards and penalties in the corticostriatal pathway in adults with ADHD is unclear. METHODS: Single-photon emission computed tomography with [99mTC]TRODAT-1 was used to assess striatal dopamine transporter (DAT) availability. Event-related functional magnetic resonance imaging was conducted on subjects performing the Iowa Gambling Test. RESULT: DAT availability was found to be associated with the BOLD response, which was a covariate of monetary loss, in the medial prefrontal cortex (r = 0.55, P = .03), right ventral striatum (r = 0.69, P = .003), and right orbital frontal cortex (r = 0.53, P = .03) in adults with ADHD. However, a similar correlation was not found in the controls. CONCLUSIONS: The results confirmed that dopaminergic tone may play a different role in the penalty-elicited response of adults with ADHD. It is plausible that a lower neuro-threshold accompanied by insensitivity to punishment could be exacerbated by the hypodopaminergic tone in ADHD.

Effect of fasting duration on myocardial fluorodeoxyglucose uptake in diabetic and nondiabetic patients.

OBJECTIVE: To detect cardiac hypermetabolic lesions using fluorodeoxyglucose (FDG) with PET/computed tomography (PET/CT), the efficiency of long fasting and temperature condition for lowering physiological myocardial FDG uptake is controversial and may be confounded by other factors. We thus aimed to investigate the impact of fasting duration and ambient temperature on myocardial uptake in diabetic and nondiabetic patients. METHODS: FDG PET/CT scans (n = 666) were reviewed and the myocardial uptake was visually graded on a four-point scale and quantified using standardized uptake value (SUV). The associations between myocardial uptake and fasting duration, diabetes status, ambient temperature parameters, age, gender, and BMI were evaluated. RESULTS: Intraobserver [κ = 0.94; intraclass correlation coefficient (ICC) = 0.99] and interobserver (κ = 0.91; ICC = 0.99) reliabilities of both visual and SUV measurements were all excellent. Fasting duration and diabetes status were found to be significantly associated with myocardial FDG uptake, but the ambient temperature parameters and other factor were not. Patients with intense (Grade 4) myocardial uptake had a shorter fasting duration (P = 0.011). The SUVmax of myocardium was significantly higher in nondiabetic than diabetic patients (P < 0.001). Fasting duration ≥ 12 h in diabetic and ≥16 h in nondiabetic patients was associated with low prevalence of Grade 4 uptake (4.2%, P = 0.016; 2.3%, P = 0.028). CONCLUSION: Fasting for long enough durations but not ambient temperature was associated with decreased physiological myocardial FDG uptake. A fasting duration of more than 12 h for diabetic, 16 h for nondiabetic patients is a simple and valuable recommendation.

Dysregulation of oxytocin and dopamine in the corticostriatal circuitry in bipolar II disorder.

The oxytocin (OXT) and dopamine systems synergistically facilitate striatal reactivity. Abnormal striatal activation has repeatedly been observed in patients with bipolar disorder (BD); however, such abnormality remains unclear in BD II. Here we aimed to investigate whether the corticostriatal connectivity was altered and the possible relationships among corticostriatal connectivity, OXT, and dopamine systems in BD II. Twenty-five BD II patients, as defined by the DSM-V, and 29 healthy controls (HC) were enrolled in this study. Plasma OXT was measured and striatal dopamine transporter (DAT) availability was assessed using [99mTc]TRODAT-1 single-photon emission computed tomography (SPECT). Brain network functional connectivity (FC) was measured during the resting-state using functional magnetic resonance imaging, and the dorsal caudate (DC) was selected as the seed region. The results showed that the OXT level was significantly lower in the BD II patients, while the striatal DAT availability was not significantly different between the BD II and HC groups. The BD II patients exhibited significantly lower FC between the DC and the executive control network (dorsolateral prefrontal, anterior cingulate cortex, and posterior parietal cortex) as compared with the HC. Only observed in HC, the DC-posterior parietal cortex FC was negatively correlated with the OXT level and striatal DAT availability. Our findings in the HC support a model in which the OXT and dopamine systems act in tandem to regulate corticostriatal circuitry, while the synergistic interaction was perturbed in BD II. Taken together, these results implied a maladaptive neuroplasticity in BD II.

Bridging the associations between dopamine, brain volumetric variation and IQ in drug-naïve schizophrenia.

BACKGROUND: Although patients with schizophrenia are well-known to exhibit significant brain volume reduction and cognitive function impairment, it remains unclear as to whether the reduction/impairment is correlated with dopaminergic activity under drug-naïve conditions. METHODS: 51 drug-naïve patients with and 128 healthy subjects were recruited in this study. DAT by [99mTc]TRODAT-1 single-photon emission computed tomography (SPECT), regional gray matter volume (GMV) by voxel-based morphometry (VBM) analysis, and cognitive function in terms of IQ were measured in both groups. RESULT: A significantly lower DAT availability existed in the drug-naïve group as compared with the healthy subjects (1.67 ± 0.45 vs. 1.98 ± 0.37, P < 0.005). DAT availability was significantly positively correlated with GMV in the left middle frontal lobe (r = 0.58, P < 0.005), the GMV being significantly reduced in the patients with schizophrenia (0.45 ± 0.10 vs. 0.49 ± 0.07, P < 0.005). Furthermore, the GMV in the left middle frontal lobe was significantly and positively correlated with full IQ (r = 0.34, P = 0.02) in the patients with schizophrenia, but not in the controls. CONCLUSIONS: Dysregulated dopaminergic activity may modulate volume variation in specific brain areas, and brain volume might alter IQ in drug-naïve patients with schizophrenia.

Prognostic value of volumetric metabolic parameter changes determined by during and after radiotherapy-based 18 F-FDG PET/CT in stage III non-small cell lung cancer.

The aim of this prospective study was to evaluate the prognostic value of volumetric metabolic parameters assessed by during and after radiation-based therapy 18 F-FDG PET/CT in patients with stage III non-small cell lung cancer (NSCLC). We enrolled stage III NSCLC patients who had planned to receive definitive chemo-radiation or radiotherapy (RT) and underwent 18 F-FDG PET/CT before treatment (PET1), during RT (at the fifth week, PET2) and after treatment (3 months later, PET3). By comparing with PET1, percentage changes of metabolic tumor volume (ΔMTV) and tumor total lesion glycolysis (ΔTLG) of PET2 and PET3 were calculated. We used medians of ΔTLG and ΔMTV as cut-off values to stratify patients. Their prognostic values were evaluated by progression-free survival (PFS) and overall survival (OS). Thirty patients were enrolled initially. Five were excluded due to multiple metastases or double cancer. The remaining 25 patients had PET2 at a median of 46 Gy. Data on PET3 were available in 19 patients. During-RT ΔTLG (cut-off: 65%) was a significant prognostic factor for PFS (P = 0.02) and OS (P < 0.01). During-RT ΔMTV (cut-off: 42%) had marginal significance for PFS (P = 0.07) and was significant for OS (P = 0.02). Of the PET3 parameters, neither ΔTLG nor ΔMTV was a significant prognostic factor for PFS and OS. We conclude that ΔTLG of during-RT 18 F-FDG PET/CT may predict treatment response and thus provide opportunities to modify treatment for poor responders.

Parapharyngeal Ganglioneuroma Detected by 18F-FDG PET/CT in a Patient With Hodgkin Lymphoma.

A 38-year-old woman with anterior mediastinal Hodgkin lymphoma underwent F-FDG PET/CT, revealing abnormal uptake at the left retrostyloid parapharyngeal space. After chemotherapy, follow-up PET/CT showed regression of previously avid lesions but not the left retropharyngeal mass. Subsequent MRI revealed findings suggestive of neurogenic tumor. Transoral biopsy revealed ganglioneuroma, which is uncommon in the parapharyngeal space, although usually of benign nature. This case therefore highlights the importance of PET/CT in both initial diagnostic screening for tumor development and posttreatment evaluation of ambiguous lesions.

Post-chemoradiotherapy FDG PET with qualitative interpretation criteria for outcome stratification in esophageal squamous cell carcinoma.

OBJECTIVES: Post-chemoradiotherapy (CRT) FDG PET is a useful prognosticator of esophageal cancer. However, debate on the diverse criteria of previous publications preclude worldwide multicenter comparisons, and even a universal practice guide. We aimed to validate a simple qualitative interpretation criterion of post-CRT FDG PET for outcome stratification and compare it with other criteria. METHODS: The post-CRT FDG PET of 114 patients with esophageal squamous cell carcinoma (ESCC) were independently interpreted using a qualitative 4-point scale (Qual4PS) that identified focal esophageal FDG uptake greater than liver uptake as residual tumor. Cohen's κ coefficient (κ) was used to measure interobserver agreement of Qual4PS. The Kaplan-Meier method and Cox proportional hazards regression analyses were used for survival analysis. Other criteria included a different qualitative approach (QualBK), maximal standardized uptake values (SUVmax3.4, SUVmax2.5), relative change of SUVmax between pre- and post-CRT FDG PET (ΔSUVmax), mean standardized uptake values (SUVmean), metabolic volume (MV) and total lesion glycolysis (TLG). RESULTS: Overall interobserver agreement on the Qual4PS criterion was excellent (κ: 0.95). Except the QualBK, SUVmax2.5, and TLG, all the other criteria were significant predictors for overall survival (OS). Multivariable analysis showed only Qual4PS (HR: 15.41; P = 0.005) and AJCC stage (HR: 2.47; P = 0.007) were significant independent variables. The 2-year OS rates of Qual4PS(‒) patients undergoing CRT alone (68.4%) and patients undergoing trimodality therapy (62.5%) were not significant different, but the 2-year OS rates of Qual4PS(+) patients undergoing CRT alone (10.0%) were significantly lower than in patients undergoing trimodality therapy (42.1%). CONCLUSIONS: The Qual4PS criterion is reproducible for assessing the response of ESCC to CRT, and valuable for predicting survival. It may add value to response-adapted treatment for ESCC patients, and help to decide whether surgery is warranted after CRT.