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Aim To investigate predictive and prognostic role of metabolic parameters using [18 F]-2-fluoro-2-deoxy-D-glucose positron emission tomography (18 F-FDG PET) in patients with locally advanced non-small cell lung cancer (NSCLC) treated with docetaxel-platinum induction chemotherapy (IC). Methods Medical records of 31 patients with pre- and post-IC 18 F-FDG PET were reviewed. Using 18 F-FDG PET, metabolic parameters, including metabolic tumor response, adjusted peak standardized uptake values using lean body mass at baseline (pre-SULpeak ) and after IC (post-SULpeak ), and percentage change of pre- and post-SULpeak (ΔSULpeak ), were assessed. Results Response rate (RR) was 71%, with a metabolic RR of 83.9%. Nineteen (61.3%) patients underwent surgery, R0 resection was achieved for 17 (89.5%) patients. Median relapse-free survival (RFS) and overall survival (OS) were 8.9 months (95% CI: 4.5-12.1) and 24.1 months (95% CI: 17.1-34.1), respectively. Post-SULpeak 1.4 could predict recurrence with a sensitivity of 84% and a specificity of 100%. Conclusion In patients with locally advanced NSCLC receiving IC, post-SULpeak and ΔSULpeak showed clinical significance for survival outcome.

PURPOSE: Bone single-photon emission computed tomography/computed tomography (SPECT/CT) has been widely used for evaluation of femoral head viability in patients with femoral neck fracture. The current study aimed to investigate utility of standardized uptake value (SUV) from quantitative bone SPECT/CT for assessment of femoral head viability. METHODS: From March 2015 to November 2018, quantitative bone SPECT/CT was performed in 9 patients with non-viable femoral head post femoral neck fracture and in 31 controls. Maximum (SUVmax), mean (SUVmean), and minimum standardized uptake values (SUVmin) were measured over femoral head and neck. Mann-Whitney U test with Bonferroni correction was used to compare SUVs of ipsilateral and contralateral femurs from femoral neck fracture patients with those of control femurs. RESULTS: As for femoral head viability, SUVmax and SUVmean were not significantly decreased in non-viable femoral heads compared to those in controls. Only the SUVmin was significantly reduced in non-viable femoral heads (mean ± standard deviation, 0.57 ± 0.38) than in controls (0.95 ± 0.26, p = 0.006) and contralateral femoral heads (1.36 ± 0.59, p = 0.008). The cutoff SUVmin of 0.61 (g/mL) yielded a sensitivity of 77.8% and specificity of 87.1% for detection of non-viable femoral heads (p = 0.006). Contralateral femoral necks of the femoral neck fracture patients showed significantly higher SUVmean and SUVmin (3.17 ± 1.20 and 1.64 ± 0.63) than those of controls (2.32 ± 0.53 and 1.04 ± 0.27; p = 0.021 and p = 0.002, respectively), which seemed to reflect weight bearing effect or metabolic derangement. CONCLUSIONS: The non-viable femoral heads from the femoral neck fracture showed significantly reduced SUVmin. Quantitative bone SPECT/CT holds promise for objective evaluation of femoral head viability. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13139-019-00600-2) contains supplementary material, which is available to authorized users.

Radiation proctitis is the collateral damage that occurs to healthy cells during radiation treatment of pelvic malignancies. Conservative treatment of radiation proctitis can mitigate inflammatory symptoms, but, to date, no therapeutic options are available for direct recovery of the damaged colonic epithelium. The present study assessed the ability of colon organoid-based regeneration to treat radiation proctitis. Radiation proctitis was induced in mice by irradiating their recta, followed by enema-based transplantation of mouse colon organoids. The transplanted colon organoids were found to successfully engraft onto the damaged rectal mucosa of the irradiated mice, reconstituting epithelial structure and integrity. Lgr5+ stem cells were shown to be pivotal to colon organoid mediated regeneration. Endoscopic examination showed the efficacy of localized transplantation of colon organoids with fibrin glue to irradiated sites. These findings provide useful insights into the use of colon organoid-based regenerative therapy for the treatment of radiation proctitis.

Ji Han Lee,1 Won Sang Jung,2 Woo Hee Choi,3 Hyun Kook Lim4 1Washington University in St Louis, St Louis, MO, USA; 2Department of Radiology, 3Department of Nuclear Medicine, 4Department of Psychiatry, Saint Vincent Hospital, College of Medicine, The Catholic University of Korea, Suwon, South Korea Objective: Among patients with Alzheimer’s disease (AD), sleep disturbances are common and serious noncognitive symptoms. Previous studies of AD patients have identified deformations in the brain stem, which may play an important role in the regulation of sleep. The aim of thisstudy was to further investigate the relationship between sleep disturbances and alterations in brain stem morphology in AD.Materials and methods: In 44 patients with AD and 40 healthy elderly controls, sleep disturbances were measured using the Neuropsychiatry Inventory sleep subscale. We employed magnetic resonance imaging-based automated segmentation tools to examine the relationship between sleep disturbances and changes in brain stem morphology.Results: Analyses of the data from AD subjects revealed significant correlations between the Neuropsychiatry Inventory sleep-subscale scores and structural alterations in the left posterior lateral region of the brain stem, as well as normalized brain stem volumes. In addition, significant group differences in posterior brain stem morphology were observed between the AD group and the control group.Conclusion: This study is the first to analyze an association between sleep disturbances and brain stem morphology in AD. In line with previous findings, this study lends support to the possibility that brain stem structural abnormalities might be important neurobiological mechanisms underlying sleep disturbances associated with AD. Further longitudinal research is needed to confirm these findings. Keywords: Alzheimer’s disease, sleep, brain stem, MRI, shape analysis

We aimed to evaluate the prognostic value of early response assessment using a volumetric fluorine-18-fluorodeoxyglucose (F-FDG) PET analysis in chemotherapy-treated patients with non-small-cell lung cancer (NSCLC).We retrospectively reviewed 33 patients with NSCLC who received first-line chemotherapy and performed F-FDG PET/computed tomography before (baseline PET) and after two cycles of chemotherapy (interim PET). The maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) of the total malignant lesion were measured in baseline (SUV1 and MTV1) and interim (SUV2 and MTV2) PET images, and percentage changes in SUVmax (ΔSUV) and MTV (ΔMTV) were calculated between the two images. We compared PET parameters and clinicopathologic variables in terms of the 2-year overall survival (OS).The median follow-up period was 14.3 months and the 2-year OS was 31%. In PET images, the mean SUV1, MTV1, SUV2, MTV2, ΔSUV, and ΔMTV were 13.1±4.5, 307.9±340.0 cm, 9.5±5.1, 180.4±29.6 cm, 27±28%, and 42±65%, respectively. In univariable analysis, M stage, TNM stage, and all six PET parameters associated significantly with OS. Both the MTV1 and the ΔMTV were tested against OS controlling for M stage, one at time, and the effect remained significant in multivariable analyses.A smaller baseline MTV and greater decrease in MTV between baseline and interim PET images are associated with a significantly prolonged OS. A volume-based F-FDG PET analysis would facilitate prediction of clinical outcome and identification of treatment-resistant patients early during chemotherapy and could thus be used in personalized treatment approaches for patients with NSCLC.

Background We evaluated the suitability of 18F-fluorodeoxythymidine (18F-FLT) positron emission tomography (PET)/computed tomography (CT) for assessment of the early response to induction therapy and its value for predicting clinical outcome in patients with acute myeloid leukemia (AML). Adult patients who had histologically confirmed AML and received induction therapy were enrolled. All patients underwent 18F-FLT PET/CT after completion of induction. PET/CT images were visually and quantitatively assessed. Cases with intensely increased bone marrow uptake in more than one third of the long bones and throughout the central skeleton were interpreted as PET-positive for resistant disease (RD). PET results were compared to the clinical response and outcome. Results In visual PET analysis of 10 eligible patients (7 male, 3 female; median age 58 years), 5 patients were interpreted as being PET-positive and 5 as PET-negative. Standardized uptake values were significantly different between PET-positive and PET-negative groups. Eight of 10 patients achieved clinical complete remission (CR)/CR with incomplete blood count recovery (CRi). Five CR/CRi patients had PET-negative findings, but 3 CR patients had PET-positive findings. Both of the RD patients had PET-positive findings. During follow-up, 2 CR patients with PET-positive findings relapsed, or were strongly suspected of relapse, 4 months after consolidation. Conclusion 18F-FLT PET/CT after induction therapy showed good sensitivity and negative-predictive value for evaluating RD in patients with AML. This preliminary study suggests that 18F-FLT PET/CT may be valuable as a noninvasive tool for early assessment of the response to treatment and may provide prognostic value for survival in patients with AML.

Background Limited disease small-cell lung cancer responds well to concurrent chemoradiation therapy (CCRT), but shows high relapse rate and short RFS. We aimed to evaluate tumor metabolic activities measured using FDG-PET as a prognostic factor and analyze its relationships with markers of tumor biologic behavior. Patients and Methods Forty-one LD-SCLC patients receiving 4 cycles of EP (etoposide 120 mg/m 2 , days 1-3; cisplatin 60 mg/m 2 , day 1), 2 cycles of EP (etoposide 130 mg/m 2 , days 1-3; cisplatin 30 mg/m 2 , day 1)-CCRT were enrolled. Maximum standardized uptake value (SUV; SUVmax) of primary tumor was revised with SUV of liver (SUVlivermax). Differences between pre-, posttreatment average SUV uptake of primary tumor, and intrathoracic lymph nodes were presented as ΔSUVliveravg. Thirty-one tumor biopsy specimens were immunostained for GLUT-1, Bcl-2, and HIF-1α. Results The median overall survival (OS), and RFS were 13.7 and 10.4 months, respectively. In multivariate analysis, pretreatment lactate dehydrogenase (LDH) and ΔSUVliveravg correlated with RFS (hazard ratio [HR], 2.8, P = .043; HR, 0.3, P = .004). Sex, LDH, objective tumor metabolic response, and SUVlivermax correlated with OS (HR, 12.1, P = .006; HR, 3.7, P = .037; HR, 10.1, P = .008; and HR, 0.2, P = .014, respectively). High GLUT-1 positivity (> 75%), and LDH level (> 400 U/L) correlated with better objective response rate ( P = .012) and HIF-1α immunoreactivity score ( P = .029). Conclusion ΔSUVliveravg and GLUT-1 expression might predict RFS and ORR in patients with LD-SCLC treated with definitive CCRT.

The therapeutic effect of bone marrow stimulation techniques (BSTs) is mainly attributed to the role of mesenchymal stem cells (MSCs) from the bone marrow. However, no studies have directly shown the amount of MSCs drained by BSTs. This study hypothesized that differences in the opening of subchondral bone affect the number of MSCs drained from the bone marrow. We purposed that as the exposed area and hole size of BSTs vary, the number of MSCs drained out was measured. Three groups of different BSTs were designed that have variations in the sizes of total exposed area and individual holes. Three different BSTs using a curette, 1.5- and 0.8-mm awls were carried out on the full-thickness femoral cartilage defect of young rabbits. After BST, the number of MSCs in the blood clot was measured by CFU-Fs assay. As the size of the total exposed area increased, so did the number of MSCs obtained. The number of MSCs drained from bone marrow may vary depending on different BSTs and this could affect therapeutic efficacy of cartilage defect. As current microfracture (MF) method cannot drain the most MSCs clinically, more improved surgery technique is needed.

With recent advancement in amyloid imaging, diagnostic application of this new modality has become a great interest among researchers. New ligands, such as 18F- florbetaben, florbetapir and flutemetamol, have been discovered to overcome limitations of preexisting ligand Pittsburgh compound B. We report here a case of a 37-year-old male patient whose initial complaints comprised of gradual cognitive decline, apraxia, disorientation and sleep disturbances. 18F-Florbetaben amyloid imaging of the patient showed diffuse amyloid retention with prominent striatal uptake. This finding supports the clinical utility of amyloid imaging in diagnostic process of early-onset AD. Moreover, striatal dominant uptake pattern demonstrated in this patient include some meaningful clinical implications that warrant special attention among clinicians.

This study assessed the effect of bevel direction on the success rate of ultrasound guided radial artery catheterization. A total of 204 patients requiring radial artery catheterization were randomly divided into bevel-up (n = 102) and bevel-down (n = 102) groups. Success rate, cannulation time, and number of attempts were compared groups. In the bevel-down group, an arterial line was placed on the first attempt in 86 of 102 (84.3 %; 95 % confidence interval [CI] = 76 % to 90 %) patients versus 73 of 102 (71.6 %; 95 % CI = 62.1 % to 79.4 %) in the bevel-up group (p = 0.028). In the bevel-down group, the mean time to a successful radial arterial cannulation was 33.3 ± 6.3 seconds (95 % CI = 32.1-34.6) versus 35.9 ± 7.6 seconds (95 % CI = 34.4-37.2) in the bevel-up group (p = 0.011). The median score was 33.2 and interquartile range [IQR] was 10.9 (30.3-41.2) for the mean cannulation time in the bevel-up group. In the bevel-down group, the mean score was 32.3 (IQR 3.90, 30–33.9) for mean cannulation time. In the bevel-down group, 11 of 102 (7 %; 95 % CI = 0 to 16 %) patients developed a posterior wall puncture versus 22 of 102 ((21.6 %; 95 % CI = 14.7 to 17.2 %) in the bevel-up group. The bevel-down approach during ultrasound-guided radial artery catheterization exhibited a higher success with fewer complications compared to the bevel-up approach. Clinical Research Information Service is Korean Clinical Trials Registry ( KCT0001836 ). It was registered retrospectively 30th Nov 2015.

Background Although there is substantial evidence of associations between frontal-striatal circuits and cerebral vascular burden in late-onset depression (LOD), relationships between vascular burden and hippocampal subfields are not clear. The purpose of this study was to investigate relationships between cerebral vascular burden and hippocampal subfield volume in LOD patients. Methods Fifty subjects with LOD and 50 group-matched healthy control subjects underwent magnetic resonance imaging scanning. Hippocampal subfields volumes were measured and compared between the groups. In addition, association patterns between white matter hyperintensity (WMH) volumes, clinical measures and hippocampal subfield volumes were investigated in the LOD group. Results Subjects with LOD exhibited significant hippocampal volume reductions in the total hippocampus, cornu ammonis (CA) 1 and 3 and dentate gyrus (DG) areas compared with healthy subjects. Total WMH volume was negatively correlated with left total hippocampal volume and CA1 in the LOD group. In addition, depression severity was negatively associated with left and right CA3 volumes in the LOD group. Limitation Our findings of distinctive relationships between WMH and hippocampal subfields demonstrate a simple correlation, but do not prove causation Conclusion This study is the first to elaborate distinctive association patterns between hippocampal subfield volumes and cerebral vascular burden in LOD. These structural changes in the hippocampal CA1, CA3 and DG areas might be at the core of the underlying neurobiological mechanisms of hippocampal dysfunction in LOD. However, longitudinal studies will be needed to identify the mechanisms of these structural changes.

We aimed to evaluate the diagnostic and prognostic value of post-treatment fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in patients treated for ovarian malignancy. We retrospectively reviewed post-treatment PET/CT images of patients treated for histologically confirmed ovarian malignancy. The diagnostic accuracy of PET/CT for detection of disease recurrence or second primary malignancy was calculated, and the impact of PET/CT on patient management was evaluated. The association between PET/CT result and overall survival (OS) was assessed using Cox regression analysis. In total, 416 PET/CT cases of 268 ovarian malignancy patients (mean age, 50 ± 13 years) were included. Of 416 cases, 87 (21 %) were interpreted as PET/CT positive and 329 as negative. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 98.8, 98.2, 98.3, 93.1 and 99.7 %, respectively. Of 362 cases for surveillance, changes in management occurred based on PET/CT in 38 (11 %). Of 54 cases with clinical suspicion, PET/CT ruled out disease recurrence in 9 (17 %). The median follow-up period from PET/CT imaging was 26.7 months, and 24 patients (9 %) died during the follow-up period. In univariate analyses, age, FIGO stage, history of prior recurrence and PET/CT results were significantly associated with OS. PET/CT results remained significantly associated with OS in the multivariate analysis (p

OBJECTIVES The purpose of this study was to evaluate the clinical value of preoperative [(18)F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) by comparing it to neck sonography in papillary thyroid carcinoma. METHODS The diagnostic accuracies of PET/CT and sonography for detecting cervical node metastasis were compared. The association between FDG uptake in the primary tumor and the prognostic factors of differentiated thyroid cancer, such as tumor size, multiplicity, extrathyroid extension, and lymph node metastasis, was also assessed. RESULTS Positron emission tomography/computed tomography showed lower sensitivity and higher specificity than sonography for detection of cervical node metastasis; however, no statistically significant difference was noted (P > .99). Only the tumor size was associated with FDG uptake in the primary tumor. CONCLUSIONS [(18)F]Fluoro-2-deoxy-d-glucose PET/CT could not provide additional information compared to neck sonography.

Though 18F-FDG PET/CT scans are widely used in non-small cell lung cancer (NSCLC), the mechanism of FDG uptake by lung cancer cells has not yet been fully elucidated. This study evaluated the relationship between FDG uptake and the expression of glucose transporters in NSCLC. Sixty-four NSCLC patients who underwent both preoperative 18F-FDG PET/CT scanning and thoracotomy were included. The maximum standardized uptake value (SUVmax) of the primary lung cancer was compared to the immunohistochemistry results for Glut expression and tumor size. In all the NSCLC cases, degree of FDG uptake significantly correlated with both Glut-1 and Glut-3 expression. When stratified by the histology, squamous cell carcinomas showed higher mean SUVmax, Glut-1 expression intensity, and percentage of area positive for Glut-1 expression than adenocarcinomas. Glut-1 and Glut-3 expressions correlated with SUVmax in adenocarcinomas, but there was no significant correlation in squamous cell carcinomas. No significant correlation was observed between tumor size and FDG uptake or Glut expression. These results show that Glut expression was significantly correlated with SUVmax in NSCLC, especially in adenocarcinomas, and that neither FDG uptake nor the expression of Glut was associated with tumor size.

Parkinson's disease dementia (PDD) is notorious for its debilitating clinical course and high mortality rates. Consequently, various attempts to investigate predictors of cognitive decline in Parkinson's disease (PD) have been made. Here we report a case of a 75-year-old female patient with PD who visited the clinic with complaints of recurrent visual hallucinations and cognitive decline, whose symptoms were ameliorated by the titration of rivastigmine. Imaging results showed pronounced diffuse cortical amyloid deposition evidenced by 18F-florbetaben amyloid positron emission tomography (PET) imaging. This observation suggests that pronounced amyloid deposition and visual hallucinations in PD patients could be clinically significant predictors of cognitive decline in PD patients. Future research should concentrate on accumulating more evidence for possible predictors of cognitive decline and their association with PD pathology that can enable an early intervention and standardized treatment in PDD patients.

A 19-year-old girl presented with lower abdominal pain. Pelvic ultrasound showed a large cystic mass in the pelvic cavity, and CA19-9 was markedly elevated. On further evaluation, (18)F-FDG PET/CT showed heterogeneous, localized FDG uptake with a central photon defect in the pelvic cavity, and most intense FDG uptake was noted in the anterior portion of lesion adjacent to the ileum. Corresponding enhanced CT showed a cystic mass abutting the ileum with wall thickening. Laparoscopic resection was done and the histologic result was adenocarcinoma arising in Meckel's diverticulum.

A 68-year-old man underwent total gastrectomy for stomach cancer. On the follow-up FDG PET/CT image 18 months later, intense focal (18)F-fluorodeoxyglucose (FDG) uptake was noted in the right parapharyngeal space. This lesion showed intermediate signal intensity on T1-weighted image and heterogeneous high signal intensity on T2-weighted image. The mass was heterogenously enhanced by gadolinium enhancement. This lesion was pathologically confirmed as pleomorphic adenoma by excision. This case highlights the fact that both benign and malignant lesions in the parotid gland may exhibit intense FDG activity and the need for pathologic confirmation of parotid gland lesions for accurate disease staging.

The purpose of this study was to identify the frequency and possible cause of diffuse intrathoracic uptake on post-therapy I-131 scans in thyroid cancer patients.We retrospectively reviewed 781 post-therapy scans of 755 thyroid cancer patients who underwent total thyroidectomy and radioactive iodine therapy between January and December 2010. Diffuse intrathoracic uptake on post-therapy scans was examined, and clinical patient characteristics including sex, age, regimen for thyroid-stimulating hormone (TSH) stimulation (thyroid hormone withdrawal or recombinant human TSH injection), TSH, thyroglobulin (Tg) and anti-thyroglobulin antibody (anti-Tg Ab) levels, therapeutic dose of radioactive iodine therapy and prior history of radioactive iodine therapy were recorded.Scan findings were correlated with chest CT, chest radiographs, laboratory tests and/or clinical status. Diffuse intrathoracic uptake without evidence of pathologic condition was categorized as indeterminate. The association between clinical characteristics and intrathoracic uptake were analyzed for negative intrathoracic uptake and indeterminate uptake groups.Diffuse intrathoracic uptake on post-therapy scans was demonstrated in 39 out of 755 (5.2 %) patients, among which 3 were confirmed as lung metastasis. The 14 patients that showed high Tg or anti-Tg Ab levels were considered to be at risk of having undetected micrometastasis on other imaging modalities. The remaining 22 were indeterminate (2.9 %).Upon comparison of negative intrathoracic uptake and indeterminate uptake groups, TSH stimulation by thyroid hormone withdrawal was shown to be significantly correlated with diffuse intrathoracic uptake (p 0.05).The frequency of diffuse intrathoracic uptake on post-therapy scans was 5.2 % and could be seen in thyroid cancer patients with underlying lung metastasis as well as those without definite pathologic condition. In the latter, there was a higher frequency for diffusely increased intrathoracic uptake in those who underwent thyroid hormone withdrawal rather than recombinant human TSH injection.

The aim of this study was to assess the value of dual-time point PET/CT in the differentiation of extrahepatic cholangiocarcinoma from benign stricture and the added benefits of delayed PET/CT image.Thirty-nine patients with suspected extrahepatic biliary malignancy based on conventional imaging studies such as ultrasonography, CT, and MRI between July 2008 and December 2010 were included. All patients underwent dual-time point PET/CT scans at 1 and 2 hours after radiotracer injection. From the site of suspected malignancy, the SUVmax for both time points (SUVmax1 and SUVmax2), the percent change in SUVmax between the 2 (Δ%SUVmax) and the ratio of SUVmax1, SUVmax2, Δ%SUVmax in comparison with average SUV of right hepatic lobe (T/L ratio1, T/L ratio2, and Δ%T/L ratio) were generated. Diagnostic performances using visual assessment and various SUVmax cutoff values were analyzed in the differential diagnosis of extrahepatic cholangiocarcinoma from benign disease. PET/CT results were correlated with histological results and radiological follow-up for at least 6 months.Of 39 patients, the final diagnosis was cholangiocarcinoma in 34 and benign disease in 5. Between malignant and benign lesions, there were significant differences in SUVmax1 (5.43 ± 4.66 vs 2.26 ± 0.83, P = 0.003) and SUVmax2 (6.02 ± 5.26 vs 2.26 ± 0.76, P = 0.002). There was no significant difference in Δ%SUVmax, T/L ratio1, T/L ratio2, and Δ%T/L ratio. On receiver operator curve analysis, SUVmax1 with cutoff value of 2.5 demonstrated sensitivity of 97.6%, specificity of 60.0%, and accuracy of 92.3% and SUVmax2 with cutoff value of 3.1 demonstrated sensitivity of 88.2%, specificity of 100%, and accuracy of 89.7%.SUVmax from both early and delayed PET/CT scans are useful parameters in the differentiation of extrahepatic biliary malignancy from benign disease. However, there was no added benefit of delayed PET/CT in patients suspicious for extrahepatic cholangiocarcinoma.

A 51-year-old man was diagnosed with small cell lung cancer (SCLC) with brain, left adrenal gland, and pancreas metastases. On evaluation of treatment response after chemotherapy and radiation therapy, F-18 FDG PET/CT showed focal FDG uptake in the periappendiceal area with thickened appendiceal wall and inflammatory change. Laparoscopic appendectomy was done, and the findings were consistent with acute suppurative appendicitis with involvement of 2 small masses on the appendiceal body and tip. Histopathologic findings confirmed metastatic small cell carcinoma, involving submucosa, proper muscle, and periappendiceal fat. This is a case of appendiceal metastasis from small cell lung cancer detected on F-18 FDG PET/CT.

Purpose: Various diagnostic imaging modalities have been used to evaluate the effect of neoadjuvant chemotherapy for osteosarcoma early and noninvasively. We evaluated the effectiveness of imaging studies of plain radiographs and positron-emission tomography/computed tomography (PET/CT) in predicting neoadjuvant chemotherapy effect for osteosarcoma and tried to establish a general principle in interpretation of PET/CT parameters. Materials and Methods: Eighteen patients who underwent two cycles of neoadjuvant chemotherapy and surgical excision for osteosarcoma were enrolled. There were 13 males and 5 females, with a median age of 19 (11−63) years. Fifteen patients of 18 had the American Joint Committe on Cancer (AJCC) stage IIB. They had plain radiographs and PET/CT before and after neoadjuvant chemotherapy. The resected tumor specimens were pathologically examined to determine histological response grade using a conventional mapping method. Statistical analysis was performed to evaluate the correlation between histopathological necrosis rate, and radiographic finding category, post-chemotherapy maximum standardized uptake value (SUVmax), average standardized uptake value and metabolic tumor volume (MTV) as well as reduction rates of them. Results: Eight patients were good responders to neoadjuvant chemotherapy based on histological evaluation. Median SUVmax reduction rate was 73 (23−77) % in good responders and 42 (-32−76) % in poor responders. Median MTV reduction rate was 93.5 (62−99) % in good responders and 46 (-81−100) % in poor responders. While radiographic finding category was not different according to histological response (p=1.0), SUVmax reduction rate was significantly different (p=0.041). Difference in MTV reduction rates approached statistical significance as well (p=0.071). Conclusion: While radiographic finding category was not reliable to assess neoadjuvant chemotherapy effect for osteosarcoma, reduction rate of SUVmax was a useful indicator in this study. As parameters of PET/CT can be influenced by various factors of settings, different centers have to make an effort to establish their own standard of judgement with reference of previous studies.