[Show abstract][Hide abstract] ABSTRACT: After initial treatment of differentiated thyroid carcinoma (DTC) patients are followed with thyroglobulin (Tg) measurements to detect recurrences. In case of elevated levels of Tg and negative neck ultrasonography, patients are treated "blindly" with Iodine-131 (131I). However, in up to 50% of patients, the post-therapy scan reveals no 131I-targeting of tumor lesions. Such patients derive no benefit from the blind therapy but are exposed to its toxicity. Alternatively, iodine-124 (124I) Positron Emission Tomography/Computed Tomography (PET/CT) has become available to visualize DTC lesions and without toxicity. In addition to this, 18F-fluorodeoxyglucose (18F-FDG) PET/CT detects the recurrent DTC phenotype, which lost the capacity to accumulate iodine. Taken together, the combination of 124I and 18F-FDG PET/CT has potential to stratify patients for treatment with 131IMethods/design: In a multicenter prospective observational cohort study the hypothesis that the combination of 124I and 18F-FDG PET/CT can avoid futile 131I treatments in patients planned for 'blind' therapy with 131I, is tested.One hundred patients planned for 131I undergo both 124I and 18F-FDG PET/CT after rhTSH stimulation. Independent of the outcome of the scans, all patients will subsequently receive, after thyroid hormone withdrawal, the 131I therapy. The post 131I therapeutic scintigraphy is compared with the outcome of the 124I and 18F-FDG PET/CT in order to evaluate the diagnostic value of the combined PET modalities.This study primary aims to reduce the number of futile 131I therapies. Secondary aims are the nationwide introduction of 124I PET/CT by a quality assurance and quality control (QA/QC) program, to correlate imaging outcome with histopathological features, to compare 124I PET/CT after rhTSH and after withdrawal of thyroid hormone, and to compare 124I and 131I dosimetry.
BMC Cancer 06/2014; 14(1):405. · 3.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To explore the potential complementary value of PET/CT and dynamic contrast-enhanced MRI in predicting pathological response to neoadjuvant chemotherapy (NAC) of breast cancer and the dependency on breast cancer subtype.
We performed (18)F-FDG PET/CT and MRI examinations before and during NAC. The imaging features evaluated on both examinations included baseline and changes in (18)F-FDG maximum standardized uptake value (SUVmax) on PET/CT, and tumour morphology and contrast uptake kinetics on MRI. The outcome measure was a (near) pathological complete response ((near-)pCR) after surgery. Receiver operating characteristic curves with area under the curve (AUC) were used to evaluate the relationships between patient, tumour and imaging characteristics and tumour responses.
Of 93 patients, 43 achieved a (near-)pCR. The responses varied among the different breast cancer subtypes. On univariate analysis the following variables were significantly associated with (near-)pCR: age (p = 0.033), breast cancer subtype (p < 0.001), relative change in SUVmax on PET/CT (p < 0.001) and relative change in largest tumour diameter on MRI (p < 0.001). The AUC for the relative reduction in SUVmax on PET/CT was 0.78 (95 % CI 0.68-0.88), and for the relative reduction in tumour diameter at late enhancement on MRI was 0.79 (95 % CI 0.70-0.89). The AUC increased to 0.90 (95 % CI 0.83-0.96) in the final multivariate model with PET/CT, MRI and breast cancer subtype combined (p = 0.012).
PET/CT and MRI showed comparable value for monitoring response during NAC. Combined use of PET/CT and MRI had complementary potential. Research with more patients is required to further elucidate the dependency on breast cancer subtype.
European Journal of Nuclear Medicine 04/2014; · 4.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To investigate the association between extravesical (18)F-fluorodeoxyglucose (FDG) avid lesions on FDG-positron emission tomography/computed tomography (PET/CT) and mortality in patients with muscle-invasive bladder cancer.
An international, bi-institutional cohort study of 211 patients with muscle-invasive bladder cancer who underwent staging CT and FDG-PET/CT imaging. On the basis of the presence of extravesical FDG-avid lesions suspicious for malignancy on PET/CT images, patients were divided into a PET/CT-positive and PET/CT-negative group. Data on staging and mortality were retrospectively analyzed from prospective databases. Kaplan-Meier analyses were performed to compare overall (OS) and disease-specific survival (DSS) between the groups. Multivariable Cox regression models were used to investigate the association between extravesical PET/CT lesions and mortality. Extravesical lesions suspicious for malignancy on conventional CT were included in the models.
Of the 211 patients, 98 (46.4%) had 1 or more extravesical lesions on PET/CT, 113 (53.5%) had a negative PET/CT. Conventional CT revealed extravesical lesions in 51 patients (24.4%). Median follow-up was 18 months. Patients with a positive PET/CT had a significantly shorter OS and DSS (median OS: 14 vs 50 months, P = .001; DSS: 16 vs 50 months, P <.001). In multivariable analysis, the presence of extravesical lesions on PET/CT was an independent prognostic indicator of mortality (OS: hazard ratio = 3.0, confidence interval 95% 1.7-5.1). This association was not statistically significant for conventional CT (hazard ratio = 1.6 (95% confidence interval 0.9-2.7).
On the basis of our results, the presence of extravesical FDG-avid lesions on PET/CT might be considered an independent indicator of mortality.
[Show abstract][Hide abstract] ABSTRACT: Aim: Preoperative detection of extranodal spread (ENS) in head and neck cancer can have important consequences for patient management. The aim of this study was to determine whether 18-fluorodeoxyglucose positron emission tomography ([18F]FDG PET) or a combination with Magnetic Resonance Imaging (MRI) could more accurately predict ENS, especially with the near availability of fully integrated [18F]FDG PET/MRI scanners. Methods: In retrospective cohort design a total of twelve patients, with 18 lymphnode metastases were studied with [18F]FDG PET and MRI. Presence of ENS was scored on MRI, and [18F]FDG PET images using a SUV max cut-off point of 12. Histopathology results were used as reference standard. Sensitivity, specificity and accuracy were calculated. Results: The sensitivity, specificity and accuracy of [18F]FDG PET for ENS reached 70%,100% and 83%, respectively. The mean SUVmax of ENS positive lymphnodes was 13.6 versus 8.7 for lymphnode metastases without ENS (P=0.03). The sensitivity, specificity and accuracy of MRI for ENS were 70%, 100% and 83%, respectively. When the [18F]FDG PET and MRI findings were combined sensitivity, specificity and accuracy were 80%, 100% and 89%, respectively. Thus, accuracy increased from 83% to 89%. Conclusion: When there is no ENS or doubt of ENS on MRI, [18F]FDG PET seems to have additional value since it improves sensitivity and resolves uncertainty in case of high FDG uptake. This benefit needs to be confirmed prospectively in a larger cohort.
The quarterly journal of nuclear medicine and molecular imaging: official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), [and] Section of the Society of... 01/2014; · 1.92 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In breast cancer patients treated with neoadjuvant chemotherapy (NAC) the number of tumor-positive nodes can no longer reliably be determined. Furthermore, ultrasound (US) seems suboptimal for the detection of N3-disease. Therefore we assessed the proportion of breast cancer patients treated with NAC in which pre-chemotherapy 18F-FDG PET/CT detected ≥4 axillary nodes or occult N3-disease, upstaging nodal status and changing risk estimation for locoregional recurrence (LRR). Conventional regional staging consisted of US with fine needle aspiration and/or sentinel lymph node biopsy. Patients were classified as low-risk (cT2N0), intermediate-risk (cT0N1, cT1N1, cT2N1, cT3N0), or high-risk (cT3N1, cT4, cN2-3) for LRR. The presence and number of FDG-avid nodes were evaluated and the proportion of patients that would be upstaged by PET/CT, based on detection of ≥4 FDG-avid axillary nodes defined as cN2(4+) or occult N3-disease, was calculated. In total, 87 of 278 patients were considered high-risk based on conventional staging. PET/CT detected occult N3-disease in 5 (11 %) of 47 low-risk patients. In 144 intermediate-risk patients, PET/CT detected ≥4 FDG-avid nodes in 24 (17 %) patients and occult N3-disease in 22 (15 %) patients, thereby finally upstaging 38 (26 %) of intermediate-risk patients. Of 43 (23 %) upstaged patients, 18 were ypN0, 12 were ypN1, and 13 were ypN2-3. Pre-chemotherapy PET/CT is valuable for selection of breast cancer patients at high risk for LRR. In our population, 23 % of patients treated with NAC were upstaged to the high-risk group based on PET/CT information, potentially benefiting from regional radiotherapy.
Breast Cancer Research and Treatment 09/2013; · 4.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To define the correlation between the core biopsy location and the area with highest metabolic activity on 18F-FDG PET/CT in stage II-III breast cancer patients before neoadjuvant chemotherapy. Also, we would like to select a subgroup of patients in which PET/CT information may optimize tumor sampling.
A PET/CT in prone position was acquired in 199 patients with 203 tumors. The distance and relative difference in standardized uptake value (SUV) between core biopsy localization (indicated by a marker) and area with highest degree of FDG uptake were evaluated. A distance ≥2cm and a relative difference in SUV ≥25% were considered clinically relevant and a combination of both was defined as non-correspondence. Non-correspondence for different tumor characteristics (TNM stage, lesion morphology on MRI and PET/CT, histology, subtype, grade, and Ki-67) was assessed.
Non-correspondence was found in 28 (14%) of 203 tumors. Non-correspondence was significantly associated with T-stage, lesion morphology on MRI and PET/CT, tumor diameter, and histologic type. It was more often seen in tumors with a higher T-stage (p=0.028), diffuse (non-mass) and multifocal tumors on MRI (p=0.001), diffuse and multifocal tumors on PET/CT (p<0.001), tumors >3cm (p<0.001), and lobular carcinomas (p<0.001). No association was found with other features.
Non-correspondence between the core biopsy location and area with highest FDG uptake is regularly seen in stage II-III breast cancer patients. PET/CT information and possibly FDG-guided biopsies are most likely to improve pretreatment tumor sampling in tumors >3cm, lobular carcinomas, and diffuse and multifocal tumors.
European journal of radiology 08/2013; · 2.65 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To investigate the value of response monitoring in both the primary tumour and axillary nodes on sequential PET/CT scans during neoadjuvant chemotherapy (NAC) for predicting complete pathological response (pCR), taking the breast cancer subtype into account.
In 107 consecutive patients 290 PET/CT scans were performed at baseline (PET/CT1, 107 patients), after 2 - 3 weeks of chemotherapy (PET/CT2, 85 patients), and after 6 - 8 weeks (PET/CT3, 98 patients). The relative changes in SUVmax (from baseline) of the tumour and the lymph nodes and in both combined (after logistic regression), and the changes in the highest SUVmax between scans (either tumour or lymph node) were determined and their associations with pCR of the tumour and lymph nodes after completion of NAC were assessed using receiver operating characteristic (ROC) analysis.
A pCR was seen in 17 HER2-positive tumours (65 %), 1 ER-positive/HER2-negative tumour (2 %), and 16 triple-negative tumours (52 %). The areas under the ROC curves (ROC-AUC) for the prediction of pCR in HER2-positive tumours after 3 weeks were 0.61 for the relative change in tumours, 0.67 for the combined change in tumour and nodes, and 0.72 for the changes in the highest SUVmax between scans. After 8 weeks equivalent values were 0.59, 0.42 and 0.64, respectively. In triple-negative tumours the ROC-AUCs were 0.76, 0.84 and 0.76 after 2 weeks, and 0.87, 0.93 and 0.88 after 6 weeks, respectively.
In triple-negative tumours a PET/CT scan after 6 weeks (three cycles) appears to be optimally predictive of pCR. In HER2-positive tumours neither a PET/CT scan after 3 weeks nor after 8 weeks seems to be useful. The changes in SUVmax of both the tumour and axillary nodes combined correlates best with pCR.
European Journal of Nuclear Medicine 08/2013; · 4.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To evaluate the clinical impact of (18) F-fluorodeoxyglucose (FDG)-positron-emission tomography/computed tomography (PET/CT) scanning, compared with conventional staging with contrast-enhanced CT imaging (CECT).
The FDG-PET/CT results of 96 consecutive patients with bladder cancer were analysed. Patients included in this study underwent standard CECT imaging of the chest and abdomen/pelvis <4 weeks before FDG-PET/CT. Based on the original imaging reports and recorded tumour stage before and after FDG-PET/CT imaging, the preferred treatment strategies before FDG-PET/CT and after FDG-PET/CT were determined for each patient using an institutional multidisciplinary guideline. One of the following treatment strategies was chosen: (i) local curative treatment; (ii) neoadjuvant/induction chemotherapy; or (iii) palliation. The changes in management decisions before and after FDG-PET/CT were assessed.
The median (range) interval between CECT and FDG-PET/CT was 0 (029) days. In 21.9% of the patients, stage on FDG-PET/CT and CECT were different. Upstaging by FDG-PET/CT was more frequent than downstaging (19.8 vs 2.1%). Clinical management changed for 13.5% of patients as a result of FDG-PET/CT upstaging. In eight patients, FDG-PET/CT detected second primary tumours. This led to changes of bladder cancer treatment in another four of 96 patients (4.2%). All the management changes were validated by tissue confirmation of the additional lesions.
FDG-PET/CT provides important additional staging information, which influences the treatment of carcinoma invading bladder muscle in almost 20% of cases. Patient selection for neoadjuvant/induction chemotherapy was improved and futile attempts at curative treatment in patients found to have metastases were avoided.
[Show abstract][Hide abstract] ABSTRACT: Background. The aim of this study was to assess the accuracy of 18F-FDG PET/CT in T1 breast cancer regarding visualization of the primary tumor and the detection of locoregional and distant metastases. Methods. Sixty-two women with invasive T1 breast cancer underwent a PET/CT. Image acquisition of the thorax was done in prone position with hanging breasts, followed by whole-body scanning in supine position. Primary tumor FDG uptake was evaluated and compared with clinical and histopathological characteristics. Presence of locoregional and distant metastases was assessed and compared with conventional imaging procedures. Results. The primary tumor was visible with PET/CT in 54 (87%) of 62 patients, increasing from 59% (10/17) in tumors ≤ 10 mm to 98% (44/45) in tumors over 10 mm. All triple negative and HER2-positive tumors and 40/48 (83%) ER-positive/HER2-negative tumors were visualized. Sensitivity and specificity of PET/CT in the detection of axillary metastases were 73% and 100%, respectively. PET/CT depicted periclavicular nodes in two patients. Of 12 distant lesions, one was confirmed to be a lung metastasis, three were false positive, and eight were new primary proliferative lesions. Conclusion. Using optimal imaging acquisition, the majority of T1 breast carcinomas can be visualized with PET/CT. Specificity in the detection of axillary metastases is excellent, but sensitivity appears to be limited. Additional whole body imaging has a low yield in this specific patient group.
[Show abstract][Hide abstract] ABSTRACT: Purpose
We evaluated FDG-positron emission tomography/computerized tomography for monitoring the response of pelvic lymph node metastasis to neoadjuvant chemotherapy for bladder cancer. We compared this to contrast enhanced computerized tomography.
Materials and Methods
Included in study were 19 consecutive patients with lymph node positive bladder cancer who underwent FDG-positron emission tomography/computerized tomography and contrast enhanced computerized tomography before and after a median of 4 cycles (range 2 to 4) of neoadjuvant chemotherapy between September 2011 and April 2012. Metabolic response was assessed according to EORTC (European Organisation for Research and Treatment of Cancer) recommendations based on the change in FDG uptake on FDG-positron emission tomography/computerized tomography. Radiological response was assessed on contrast enhanced computerized tomography according to RECIST (Response Evaluation Criteria in Solid Tumors) 1.1. All patients underwent pelvic lymph node dissection. Histopathological evaluation served as the gold standard for the nodal response.
Before neoadjuvant chemotherapy, hypermetabolic FDG uptake was seen in all 19 patients, which matched the lymph node metastasis. Evaluating the nodal response with positron emission tomography/computerized tomography was feasible in all patients. On histopathology 16 patients were responders, including 14 with a complete pathological response of the lymph nodes. Positron emission tomography/computerized tomography and contrast enhanced computerized tomography correctly distinguished responders from nonresponders (18 of 19 patients or 94.7% and 15 of 19 or 78.9%) and complete responders from patients with residual disease (13 of 19 or 68.4% and 12 of 19 or 63.2%, respectively).
Although no definitive conclusions can be drawn from these preliminary data, positron emission tomography/computerized tomography appears feasible for evaluating the nodal response to neoadjuvant chemotherapy and distinguishing responders from nonresponders.
The Journal of urology 05/2013; 189(5):1687–1691. · 3.75 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: If all initially node-positive patients undergo axillary lymph node dissection (ALND) after neoadjuvant chemotherapy (NAC), overtreatment may occur in patients with complete response. Positron emission tomography-computed tomography (PET/CT) during NAC may predict axillary response and select patients appropriate for less invasive treatment after NAC. We evaluated the value of sequential 18F fluorodeoxyglucose (FDG) PET/CTs during NAC for axillary response monitoring in stage II-III breast cancer. METHODS: A total of 219 PET/CTs were performed in 80 patients with cytology-proven, node-positive disease at baseline (PET/CT1, n = 80) and twice during NAC (PET/CT2 n = 62, PET/CT3, n = 77). The relative changes in maximum standardized uptake value (SUVmax) of axillary nodes were examined for their ability to assess pathological response. All patients underwent ALND after chemotherapy, and complete axillary response (pCR), defined as absence of isolated tumor cells and of micro- and macrometastases, served as the reference standard. RESULTS: A total of 32 (40 %) patients experienced axillary pCR. The relative decrease in SUVmax was significantly higher in patients with pCR than in those without, both on PET/CT2 (p < 0.001) and PET/CT3 (p = 0.025). The area under the receiver operating characteristic curve values for PET/CT2 and PET/CT3 were 0.80 (95 % confidence interval 0.68-0.92) and 0.65 (95 % confidence interval 0.52-0.79), respectively. A relative decrease of ≥60 % on PET/CT2 had an excellent specificity (35 of 37, 95 %), a high positive predictive value (12 of 14, 86 %), and a sensitivity of 48 %-that is, it accurately identified histologic pCR in 12 of 25 patients with disease that responded to therapy. CONCLUSIONS: 18F-FDG PET/CT early during NAC is useful for axillary response monitoring in cytology-proven node-positive breast cancer because it identifies pathological response, thus permitting ALND to be spared.
Annals of Surgical Oncology 03/2013; · 4.12 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Aim: Recently, a high-resolution dedicated PET system for hanging breast imaging (MAMMI PET) has been developed to improve primary tumor detection and characterization. The aim of this pilot study was to assess its feasibility for tumor detection and FDG uptake measurements in patients with stage II and III breast cancer. Methods: Thirty-two patients with invasive breast cancer (26 ductal, 4 lobular, 2 other), prior to and/or during neoadjuvant chemotherapy, underwent both conventional PET/CT and MAMMI PET in prone position with hanging breasts. Conventional PET/CT and MAMMI PET were performed 60±10 min and 110±10 min after injection of 180-240 MBq of FDG, respectively. Primary tumor detection was assessed and FDG uptake, expressed as maximum standardized uptake value (SUVmax), was calculated. Results: Both MAMMI PET and conventional PET/CT visualized the primary tumor in 31 patients (97%). The mean distance from the tumor to the pectoral muscle was 26.4mm (smallest distance 3.3mm). Agreement in FDG uptake between PET/CT and MAMMI PET was high (r=0.86, 95% CI 0.69-0.94). However, SUVmax as assessed with MAMMI PET was consistently higher than with PET/CT in all patients with an average ratio of 2.7. Conclusion: The dedicated high-resolution breast PET with hanging breast technique is able to visualize approximately all breast tumors in stage II and III breast cancer patients, including tumors in the vicinity of the thoracic wall. This may enable its sequential use in the assessment of response in breast cancer patients receiving neoadjuvant systemic therapy, although SUVmax values are not directly comparable to standard PET/CT.
The quarterly journal of nuclear medicine and molecular imaging: official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), [and] Section of the Society of... 03/2013; 57(1):92-100. · 1.92 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Failure of locoregional control is the main cause of recurrence in advanced head and neck cancer. This multi-center trial aims to improve outcome in two ways. Firstly, by redistribution of the radiation dose to the metabolically most FDG-PET avid part of the tumour. Hereby, a biologically more effective dose distribution might be achieved while simultaneously sparing normal tissues. Secondly, by improving patient selection. Both cisplatin and Epidermal Growth Factor Receptor (EGFR) antibodies like Cetuximab in combination with Radiotherapy (RT) are effective in enhancing tumour response. However, it is unknown which patients will benefit from either agent in combination with irradiation. We will analyze the predictive value of biological markers and 89Zr-Cetuximab uptake for treatment outcome of chemoradiation with Cetuximab or cisplatin to improve patient selection. METHODS: ARTFORCE is a randomized phase II trial for 268 patients with a factorial 2 by 2 design: cisplatin versus Cetuximab and standard RT versus redistributed RT. Cisplatin is dosed weekly 40 mg/m2 for 6 weeks. Cetuximab is dosed 250mg/m2 weekly (loading dose 400 mg/m2) for 6 weeks. The standard RT regimen consists of elective RT up to 54.25Gy with a simultaneous integrated boost (SIB) to 70Gy in 35 fractions in 6 weeks. Redistributed adaptive RT consists of elective RT up to 54.25Gy with a SIB between 64-80Gy in 35 fractions in 6 weeks with redistributed dose to the GTV and CTV, and adaptation of treatment for anatomical changes in the third week of treatment.Patients with locally advanced, biopsy confirmed squamous cell carcinoma of the oropharynx, oral cavity or hypopharynx are eligible.Primary endpoints are: locoregional recurrence free survival at 2 years, correlation of the median 89Zr-cetuximab uptake and biological markers with treatment specific outcome, and toxicity. Secondary endpoints are quality of life, swallowing function preservation, progression free and overall survival. DISCUSSION: The objective of the ARTFORCE Head and Neck trial is to determine the predictive value of biological markers and 89Zr-Cetuximab uptake, as it is unknown how to select patients for the appropriate concurrent agent. Also we will determine if adaptive RT and dose redistribution improve locoregional control without increasing toxicity.ClinicalTrials.gov Identifier: NCT01504815.
BMC Cancer 02/2013; 13(1):84. · 3.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Accurate characterization of breast tumors is important for the appropriate selection of therapy and monitoring of the response. For this purpose breast imaging and tissue biopsy are important aspects. In this study, a fully automated method for deformable registration of DCE-MRI and PET/CT of the breast is presented. The registration is performed using the CT component of the PET/CT and the pre-contrast T1-weighted non-fat suppressed MRI. Comparable patient setup protocols were used during the MRI and PET examinations in order to avoid having to make assumptions of biomedical properties of the breast during and after the application of chemotherapy. The registration uses a multi-resolution approach to speed up the process and to minimize the probability of converging to local minima. The validation was performed on 140 breasts (70 patients). From a total number of registration cases, 94.2% of the breasts were aligned within 4.0 mm accuracy (1 PET voxel). Fused information may be beneficial to obtain representative biopsy samples, which in turn will benefit the treatment of the patient.
Physics in Medicine and Biology 02/2013; 58(4):1221-1233. · 2.70 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Response monitoring with MRI during neoadjuvant chemotherapy (NAC) in breast cancer is promising, but knowledge of breast cancer subtype is essential. The aim of the present study was to evaluate the relevance of breast cancer subtypes for monitoring of therapy response during NAC with 18F-FDG PET/CT. METHODS: Evaluation included 98 women with stages II and III breast cancer. PET/CTs were performed before and after six or eight weeks of NAC. FDG uptake was quantified using maximum standardized uptake values (SUVmax). Tumors were divided into three subtypes: HER2-positive, ER-positive/HER2-negative, and triple negative. Tumor response at surgery was assessed dichotomously (presence or absence of residual disease) and ordinally (breast response index, representing relative change in tumor stage). Multivariate regression and receiver operating characteristic (ROC) analyses were employed to determine associations with pathological response. RESULTS: A (near) complete pathological response was seen in 19 (76%) of 25 HER2-positive, 7 (16%) of 45 ER-positive/HER2-negative, and 20 (71%) of 28 triple negative tumors. Multivariate regression of pathological response indicated a significant interaction between change in FDG uptake and breast cancer subtype. The area under the ROC curve was 0.35 (0.12-0.64) for HER2-positive, 0.90 (0.76-1.00) for ER-positive/HER2-negative, and 0.96 (0.86-1.00) for triple negative tumors. We found no association between age, stage, histology, or baseline SUVmax and pathological response. CONCLUSION: Response monitoring with PET/CT during NAC in breast cancer seems feasible, but is dependent on the breast cancer subtype. PET/CT may predict response in ER-positive/HER2-negative and triple negative tumors, but seems less accurate in HER2-positive tumors.
Breast (Edinburgh, Scotland) 02/2013; · 2.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: The purpose of this study was to investigate if FDG-PET and DWI identify the same or different targets for dose escalation in the GTV of HN cancer patients. Additionally, the dose coverage of DWI-targets in an FDG-PET-based dose painting plan was analyzed. MATERIALS AND METHODS: Eighteen HN cancer patients underwent FDG-PET and DWI exams, which were converted to standardized uptake value (SUV)- and apparent diffusion coefficient (ADC)-maps. The correspondence between the two imaging modalities was determined on a voxel-level using Spearman's correlation coefficient (ρ). Dose painting plans were optimized based on the 50% isocontour of the maximum SUV ( SUV(50%max)). Dose coverage was analyzed in three different SUV- and three different ADC-targets using the mean dose and the near-minimum and near-maximum doses. RESULTS: The average maximum SUV was 13.9 and the mean ADC was 1.17·10(-3) mm(2)/s. The average ρ between SUV and ADC was -0.2 (range: -0.6 to 0.4). The ADC-targets were only partly overlapping the SUV(50%max)-target and the dose parameters were significantly smaller in the ADC-targets compared to the SUV(50%max)-target. CONCLUSIONS: FDG-PET and DWI contain different information, resulting in different targets. Further information about failure patterns and dose relations can be obtained by adding DWI to currently ongoing dose painting trials.
Radiotherapy and Oncology 02/2013; · 4.52 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: To correlate radiotherapy (RT) dose to acute esophagitis (AE) by means of FDG-PET scans acquired after concurrent chemo-radiotherapy (cCRT) for locally advanced non-small-cell lung cancer (NSCLC). MATERIALS AND METHODS: Patients treated with 24×2.75Gy were selected on presence of a post-RT PET (PET(post)) scan acquired within 3months after cCRT. The value of PET(post) in relation to AE was evaluated by comparing the mean esophageal SUV of the highest 50% (〈SUV(50%)〉) between gr<2 and gr⩾2AE. The local dose on the esophagus wall was correlated to the SUV and modeled using a power-law fit. The Lyman-Kutcher-Burman (LKB) model was used to predict gr⩾2AE. The local dose-response relation was used in the LKB model to calculate the EUD. Resulting prediction accuracy was compared to D(mean), V(35), V(55) and V(60). RESULTS: Eighty-two patients were included (gr<2=25, gr⩾2=57). The 〈SUV(50%)〉 was significantly higher for gr⩾2AE (2.2 vs. 2.6, p<0.01). The LKB parameters (95% CI) were n=0.130 (0.120-0.141), m=0.25 (0.13-0.85) and TD(50)=50.4Gy (37.5-55.4), which resulted in improved predictability of AE compared to other predictors. CONCLUSION: Esophageal uptake of FDG post-cCRT reflects AE severity. Predictability of grade ⩾2AE was improved by using the local dose-SUV response model, with narrow confidence intervals for the optimized LKB parameters.
Radiotherapy and Oncology 12/2012; · 4.52 Impact Factor