Early assessment of tumor response using 18F-FDG PET/CT after one cycle of systemic therapy in patients with recurrent and metastatic breast cancer.

OBJECTIVE: This study was conducted to evaluate the usefulness of early assessment of tumor response using fluorine-18-fludeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) after one cycle of systemic therapy in patients with recurrent and metastatic breast cancer. SUBJECT AND METHODS: Thirty-three patients with recurrent or metastatic breast cancer underwent 18F-FDG PET/CT before and after one cycle of systemic therapy. Based on the European Organization for Research and Treatment of Cancer (EORTC) criteria, the maximum standardized uptake value (SUVmax) of the same lesions (up to a total of five) noted in the baseline and follow-up scans were summed (maximum of two per organ) as target lesions, and therapeutic response was evaluated. Log-rank and Cox methods were employed to determine progression-free survival (PFS) and overall survival (OS). RESULTS: Complete metabolic response (CMR), partial metabolic response (PMR), stable metabolic disease (SMD), and progressive metabolic disease (PMD) was seen in 2, 16, 11, and 4 patients, respectively. The mean reduction rates of SUVmax between 84 target lesions in 18 responders (CMR/PMR) and 75 target lesions in 15 non-responders (SMD/PMD) were -55.8% (range, -100%- -1.2%) and 0.47% (range, -48.7%- +209.4%), respectively, with a significant difference (P<0.0001). Every lesion site (local lesion, lymph node metastasis, bone metastasis, lung metastasis, and liver metastasis) showed a similar tendency. Thirty patients showed progression, and 17 died due to breast cancer after a median of 38.5 months. Responders showed significantly longer PFS than non-responders (P=0.0038). CONCLUSION: Fluorine-18-FDG PET/CT after one cycle of systemic therapy was able to reflect early metabolic changes regardless of the lesion site, and showed accuracy for early response evaluation and prediction of progression in patients with recurrent or metastatic breast cancer.

Assessment of the viability and treatment response of bone metastases in patients with metastatic castration-resistant prostate cancer using choline PET/CT.

ABSTRACT: This study aimed to evaluate the clinical use of choline-PET/CT for discriminating viable progressive osteoblastic bone metastasis from benign osteoblastic change induced by the treatment effect and evaluating the response of bone metastasis to treatment in metastatic castration-resistant prostate cancer (mCRPC) patients. Thirty patients with mCRPC underwent a total of 56 11C-choline-PET/CT scans for restaging, because 4 patients received 1 scan and 26 had 2 scans. Using 2 (pre- and post-treatment) 11C-choline-PET/CT examinations per patient, treatment response was assessed according to European Organization for Research and Treatment of Cancer (EORTC) criteria in 20 situations, in which only bony metastases were observed on 11C-choline-PET/CT scans. Viable bone metastases and osteoblastic change induced by the treatment effect were identified in 53 (94.6%) and 29 (51.8%) of 56 11C-choline-PET/CT scans, respectively. In 27 cases (48.2%), 11C-choline-PET/CT scans could discriminate the 2 entities. The mean SUVmax of the metastatic bony lesions was 5.82 ±â€Š3.21, 5.95 ±â€Š3.96, 6.73 ±â€Š5.04, and 7.91 ±â€Š3.25 for the osteoblastic, osteolytic, mixed, and invisible types, respectively. Of the 20 situations analyzed, CMR, PMR, SMD, and PMD, as determined by the EORTC, were seen in 1, 2, 3, and 14 cases, respectively. Of the 13 patients with increasing PSA trend, all 13 showed PMD. Of the 2 patients with PSA response of <50%, both 2 showed SMD. Of the 5 patients with PSA response of ≥50%, 1 showed CMR, 2 showed PMR, 1 showed SMD, and 1 showed PMD. Choline-PET/CT is very useful to discriminate viable progressive osteoblastic bone metastasis from osteoblastic change, and assess treatment response of bone metastases in mCRPC.

Assessment of tumor response to definitive chemoradiotherapy and prognosis prediction in patients with esophageal cancer judged by PET response criteria in solid tumors: multicenter study in Japan.

OBJECTIVES: The aim of the study was to evaluate PET response criteria in solid tumors (PERCIST) to indicate therapeutic response to definitive chemoradiotherapy, as well as prediction of recurrence and death in patients with esophageal cancer. METHODS: Before and after recieving definitive chemoradiotherapy, 181 patients with esophageal cancer underwent fluorodeoxyglucose-PET/computed tomography (FDG-PET/CT). PERCIST, reduction rates of tumor uptake and volume of whole lesions, tumor node metastasis (TNM) staging regarding progression-free survival (PFS), and overall survival (OS) were analyzed using log-rank and Cox methods. RESULTS: Complete metabolic response (CMR), partial metabolic response (PMR), stable metabolic disease (SMD), and progressive metabolic disease (PMD) shown by PERCIST were seen in 42 (23.2%), 113 (62.4%), 14 (7.7%), and 12 (6.6%) patients, respectively. Progression developed in 137 (75.7%) patients and 101 (56.1%) patients died (median follow-up 16.9, range 3.2-124.9 months). Those who achieved CMR showed significantly longer PFS and OS as compared with patients who did not (PMR, SMD, and PMD) (both P < 0.0001). In univariate analysis, initial clinical T status (P = 0.0048), N status (P = 0.011), and TNM stage (P = 0.0006), PERCIST (P < 0.0001), and reduction rate of peak lean body mass standardized uptake value (P < 0.0001), of metabolic tumor volume (P < 0.0001), and of total lesion glycolysis (TLG) (P < 0.0001) were associated with significantly increased OS. Multivariate analysis confirmed PERCIST [hazard ratio (HR): 13.15, 95% confidence interval (CI), 4.54-55.8; P < 0.0001], and TLG reduction rate (HR: 2.21, 95% CI, 1.04-4.68; P = 0.040) as independent OS predictors. CONCLUSION: PERCIST is useful for evaluating therapeutic response to definitive chemoradiotherapy, and predicting progression and death in patients with esophageal cancer.

Investigation of appropriate semi-quantitative index for assessment of esophageal and breast cancer treatment response in Japanese patients using 18F-FDG PET/CT findings.

OBJECTIVE: To examine the correlation of the quantitative indexes standardized uptake value (SUV), SUV corrected for lean body mass (SUL) and SUV corrected for Japanese lean body mass (SULj) with body weight to develop an appropriate quantitative index independent of body weight fluctuation for assessment of response to cancer treatment in Japanese patients. SUBJECTS AND METHODS: Fifty-six males with esophageal cancer and 30 females with breast cancer underwent fluorine-18-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) scans, once before and once after, receiving neoadjuvant chemotherapy prior to planned surgical resection. The maximum value, peak value, and average value of SUV, SUL and SULj were calculated by setting a spherical volume of interest (3cm diameter) in a normal area of the liver. The correlation between each index and body weight was obtained from the correlation coefficient (r) and the significance of the correlation was tested. RESULTS: Analyses were conducted with all patients (P<0.01), as well as after dividing into those with only esophageal (P<0.05) or breast (P<0.01) cancer. Regarding the correlation coefficient between each index and body weight, a significant difference was seen for SUVmax, SUVpeak and SUVmean. In contrast, there was no correlation with body weight for SULmax, SULpeak, SULmean, SULjmax, SULjpeak, or SULjmean in any of the 3 groups. CONCLUSION: Based on the correlation with body weight, we concluded that both SUL and SULj (SUL corrected for Japanese lean body mass) is useful for assessment of cancer treatment response in Japanese patients.

Assessment of tumor response to neoadjuvant chemotherapy in patients with breast cancer using MRI and FDG-PET/CT-RECIST 1.1 vs. PERCIST 1.0.

Therapeutic response to neoadjuvant chemotherapy (NAC) for breast cancer based on Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST) 1.0 with FDG-PET/CT measurements was evaluated, and the results compared to those obtained with currently widely used Response Evaluation Criteria in Solid Tumors (RECIST) 1.1, based on MRI measurements. MRI and FDG-PET/CT examinations were performed in 32 breast cancer patients before and after the NAC prior to a surgical resection. Chemotherapeutic response of the primary tumor and relapse-free survival (RFS) were investigated using RECIST 1.1 and PERCIST 1.0. Pathological complete response (pCR) was seen in 14 (43.8%) patients, while complete response (CR) was noted in 5, partial response in 25, stable disease in 2, and progressive disease in 0 with RECIST 1.1, and in 28, 2, 1, and 1, respectively, with PERCIST 1.0. For pCR prediction, the sensitivity, specificity, and accuracy with RECIST 1.1 were 28.6% (4/14), 94.4% (17/18), and 65.6% (21/32), and those with PERCIST 1.0 were 100% (14/14), 22.2% (4/18), and 56.3% (18/32). Five patients (15.6%) had recurrent development after a median period of 24 months (range 7.8-66.8 months). Patients who achieved CR shown by RECIST 1.1 showed slightly longer RFS than those who did not (p=0.46), whereas those with complete metabolic response (CMR) based on PERCIST 1.0 showed a relatively longer RFS than non-CMR patients (p=0.087). For prediction of pathological response to NAC in breast cancer, RECIST 1.1 and PERCIST 1.0 have complementary functions, however, FDG-PET as a post-NAC treatment assessment modality remains to be confirmed.

Assessment of tumor response to chemoradiotherapy and predicting prognosis in patients with head and neck squamous cell carcinoma by PERCIST.

PURPOSE: To evaluate therapeutic response to chemoradiotherapy and prediction of recurrence and death in patients with head and neck squamous cell carcinoma (HNSCC) using Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST). MATERIALS AND METHODS: Forty-two patients (mean 63.4, range 20-79 years) with nasopharyngeal (n = 10), oropharyngeal (n = 13), hypopharyngeal (n = 11), or laryngeal (n = 8) cancer underwent fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) before and approximately 3 months (mean 95.0, range 70-119 days) after undergoing concurrent chemoradiotherapy. The effect of PERCIST regarding progression-free survival (PFS) and overall survival (OS) was examined using log-rank and Cox methods. RESULTS: Complete metabolic response (CMR), partial metabolic response (PMR), stable metabolic disease (SMD), and progressive metabolic disease shown by PERCIST were seen in 30 (71.4%), 9 (21.4%), 3 (7.1%), and 0 patients, respectively. Fourteen (33.3%) developed recurrent disease (median follow-up 27.2, range 8.7-123.1 months) and 9 (21.4%) died (median follow-up 43.6, range 9.6-132.6 months). Furthermore, 4 (13.3%) of 30 patients with CMR developed recurrence, while 7 (77.8%) of 9 with PMR and all 3 (100%) with SMD developed recurrence. Two (6.7%) of 30 patients with CMR, 4 (44.4%) of 9 with PMR, and all 3 (100%) with SMD died. Patients who achieved CMR showed significantly longer PFS and OS as compared to those who did not (PMR and SMD) (both, p < 0.0001). CONCLUSION: PERCIST is useful for evaluating therapeutic response to chemoradiotherapy and predicting recurrence and death in HNSCC patients.

Metabolic response assessment with 18F-FDG-PET/CT is superior to modified RECIST for the evaluation of response to platinum-based doublet chemotherapy in malignant pleural mesothelioma.

PURPOSE: Efficient monitoring of tumor responsiveness to chemotherapy is essential to mitigate high mortality risks and cytotoxic effects of chemotherapeutics. However, there is no consensus on the most suitable diagnostic technique/parameters for assessing response to chemotherapy in malignant pleural mesothelioma (MPM). We compared the tumor responsiveness of MPM patients as assessed using modified RECIST (mRECIST) criteria and integrated 18F-FDG-PET/CT. METHODS: Histologically confirmed MPM patients (N=82) who were treated with three cycles of cisplatin and pemetrexed, or carboplatin and pemetrexed, were included. mRECIST and integrated 18F-FDG-PET/CT were used to evaluate MPM tumor response to chemotherapy. Metabolic non-responders were defined as those with a 25% or greater increase in SUVmax compared with the previous value. Time to progression (TTP) and overall survival (OS) were compared between metabolic-responders and non-responders. RESULTS: After three cycles of chemotherapy, 62(75.6%) of the patients were classified as having SD, 15 (18%) with partial remission (PR), and 5 (6%) with progressive disease (PD), based on mRECIST criteria. The cumulative median OS was 728.0days (95% confidence interval [CI]: 545.9-910.1) and cumulative median TTP was 365.0days (95% CI: 296.9-433.1). For the 82 patients, the disease control rate was 93.9%, whereas the metabolic response rate was only 71.9% (p<0.001). All PD and PR patients were found to be metabolic responders on 18F-FDG-PET/CT; however, among the 62mRECIST SD patients, 18 (29%) were classified as metabolic non-responders. The median TTP for metabolic responders was 13.7 months, while it was 10.0 months for non-responders(p<0.001). Metabolic responders had a trend toward longer OS, although the difference did not reach statistical significance (metabolic responders:33.9 months; non-responders: 21.6 months; p>0.05). CONCLUSION: Several mRECIST-confirmed SD MPM patients may be classified as metabolic non-responders on18F-FDGPET/CT. Metabolic response is significantly correlated with the median TTP, suggesting it should be included in the evaluation of the response to chemotherapy in MPM patients classified as mRECIST SD, to identify non-responders.

Comparison of capability of abdominal 320-detector row CT and of 16-detector row CT for small vasculature assessment.

The purpose of our study was to compare the capability of the 320-detector row CT (area-detector CT: ADCT) using the step-and-shoot scan protocol for small abdominal vasculature assessment with that of the 16-detector row CT using the helical scan protocol. Contrast-enhanced abdominal CT for preoperative assessment was administered to 25 patients, 18 of whom, suspected of having lung cancer, underwent ADCT using the step-and-shoot scan protocol, while the remaining 7, suspected of having renal cell carcinoma, underwent 16-MDCT using the helical scan protocol. Two experienced abdominal radiologists independently assessed renal interlobar and arcuate as well as mesenteric marginal (Griffith point) arteries by means of a 5-point visual scoring systems. Kappa analysis was used for evaluation of interobserver agreement. To compare the visualization capability of the two systems, the scores for each of the arteries were compared by using the Mann-Whitney U-test. Overall interobserver agreements for both systems were almost perfect (κ>0.78). Visualization scores for renal interlobar and arcuate, (p<0.0001) and mesenteric marginal (Griffith point) arteries (p<0.05) were significantly higher for ADCT than for 16-detector row CT. ADCT using the step-and-shoot scan protocol for small abdominal vasculature assessment can be considered superior to 16-detector row CT using the helical scan protocol.

Capability of abdominal 320-detector row CT for small vasculature assessment compared with that of 64-detector row CT.

OBJECTIVE: To compare the capability of 320-detector row CT (area-detector CT: ADCT) with step-and-shoot scan protocol for small abdominal vasculature assessment with that of 64-detector row CT with helical scan protocol. MATERIALS AND METHODS: Total of 60 patients underwent contrast-enhanced abdominal CT for preoperative assessment. Of all, 30 suspected to have lung cancer underwent ADCT using step-and-shoot scan protocol. The other 30 suspected to have renal cell carcinoma underwent 64-MDCT using helical scan protocol. Two experienced radiologists independently assessed inferior epigastric, hepatic subsegmental (in the segment 8), mesenteric marginal (Griffith point) and inferior phrenic arteries by using 5-point visual scoring systems. Kappa analysis was used for evaluation of interobserver agreement. To compare the visualization capability of the two systems, the Mann-Whitney U-test was used to compare the scores for each of the arteries. RESULTS: Overall interobserver agreements for both systems were almost perfect (κ>0.80). Visualization scores for inferior epigastric and mesenteric arteries were significantly higher for ADCT than for 64-detector row CT (p<0.05). No significant difference was found for hepatic subsegmental and inferior phrenic arteries. CONCLUSION: Small abdominal vasculature assessment by ADCT with step-and-shoot scan protocol is potentially equal to or better than that by 64-detector row CT with helical scan protocol.

Normal uptake of 18F-FDG in the testis: an assessment by PET/CT.

OBJECTIVE: The aim of this study was to assess the physiological uptake of 18F-fluoro-2-deoxyglucose (FDG) by an apparently normal testis with combined positron emission tomography-computed tomography (PET/CT) and its correlation with age, blood glucose level, and testicular volume. METHODS: The testicular uptake of 18F-FDG, expressed as the standardized uptake value (SUV), was measured on PET/CT images in 203 men. The correlation between SUV and age, blood glucose level, and testicular volume was assessed. RESULTS: The SUV in the total of 406 testes was 2.44 +/- 0.45 (range 1.23-3.85). The SUV was 2.81 +/- 0.43 (2.28-3.85) for 30-39 years (n = 12), 2.63 +/- 0.45 (1.77-3.75) for 40-49 years (n = 64), 2.46 +/- 0.35 (1.44-3.15) for 50-59 years (n = 82), 2.51 +/- 0.41 (1.50-3.46) for 60-69 years (n = 86), 2.43 +/- 0.47 (1.42-3.29) for 70-79 years (n = 86), and 2.18 +/- 0.45 (1.23-3.03) for 80-89 years (n = 76). When we calculated the mean SUV of bilateral testes in each patient, there were significant statistical differences between those in the age group of 30-39 years and 80-89 years, 40-49 years and 80-89 years, and 50-60 years and 80-89 years, when using an unpaired test with Bonferroni correction. The laterality index (|L - R|/(L + R) x 2) in 203 men was 0.066 +/- 0.067 (0-0.522). There was a mild correlation between the mean SUV and age (r = -0.284, P < 0.001) as well as between the mean SUV and mean volume (r = +0.368, P < 0.001). There was no correlation between the mean SUV and glucose blood level (r = -0.065, P = 0.358). CONCLUSIONS: Some uptake of FDG is observed in the normal testis and declines slightly with age. Physiological FDG uptake in the testis should not be confused with pathological accumulation.