| 1. |
- Anand, Aseem, et al.
(författare)
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A preanalytic validation study of automated bone scan index : Effect on accuracy and reproducibility due to the procedural variabilities in bone scan image acquisition
- 2016
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 2159-662X. ; 57:12, s. 1865-1871
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Tidskriftsartikel (refereegranskat)abstract
- The effect of the procedural variability in image acquisition on the quantitative assessment of bone scan is unknown. Here, we have developed and performed preanalytical studies to assess the impact of the variability in scanning speed and in vendor-specific γ-camera on reproducibility and accuracy of the automated bone scan index (BSI). Methods: Two separate preanalytical studies were performed: a patient study and a simulation study. In the patient study, to evaluate the effect on BSI reproducibility, repeated bone scans were prospectively obtained from metastatic prostate cancer patients enrolled in 3 groups (Grp). In Grp1, the repeated scan speed and the γ-camera vendor were the same as that of the original scan. In Grp2, the repeated scan was twice the speed of the original scan. In Grp3, the repeated scan used a different γ-camera vendor than that used in the original scan. In the simulation study, to evaluate the effect on BSI accuracy, bone scans of a virtual phantom with predefined skeletal tumor burden (phantom-BSI) were simulated against the range of image counts (0.2, 0.5, 1.0, and 1.5 million) and separately against the resolution settings of the γ-cameras. The automated BSI was measured with a computer-automated platform. Reproducibility was measured as the absolute difference between the repeated BSI values, and accuracy was measured as the absolute difference between the observed BSI and the phantom-BSI values. Descriptive statistics were used to compare the generated data. Results: In the patient study, 75 patients, 25 in each group, were enrolled. The reproducibility of Grp2 (mean ± SD, 0.35 ± 0.59) was observed to be significantly lower than that of Grp1 (mean ± SD, 0.10 ± 0.13; P < 0.0001) and that of Grp3 (mean ± SD, 0.09 ± 0.10; P < 0.0001). However, no significant difference was observed between the reproducibility of Grp3 and Grp1 (P = 0.388). In the simulation study, the accuracy at 0.5 million counts (mean ± SD, 0.57 ± 0.38) and at 0.2 million counts (mean ± SD, 4.67 ± 0.85) was significantly lower than that observed at 1.5 million counts (mean ± SD, 0.20 ± 0.26; P < 0.0001). No significant difference was observed in the accuracy data of the simulation study with vendor-specific γ-cameras (P 5 0.266). Conclusion: In this study, we observed that the automated BSI accuracy and reproducibility were dependent on scanning speed but not on the vendor-specific γ-cameras. Prospective BSI studies should standardize scanning speed of bone scans to obtain image counts at or above 1.5 million.
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| 2. |
- Anand, Aseem, et al.
(författare)
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Assessing Radiographic Response to 223Ra with an Automated Bone Scan Index in Metastatic Castration-Resistant Prostate Cancer Patients
- 2020
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 2159-662X .- 1535-5667. ; 61:5, s. 671-675
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Tidskriftsartikel (refereegranskat)abstract
- For effective clinical management of patients being treated with 223Ra, there is a need for radiographic response biomarkers to minimize disease progression and to stratify patients for subsequent treatment options. The objective of this study was to evaluate an automated bone scan index (aBSI) as a quantitative assessment of bone scans for radiographic response in patients with metastatic castration-resistant prostate cancer (mCRPC). Methods: In a multicenter retrospective study, bone scans from patients with mCRPC treated with monthly injections of 223Ra were collected from 7 hospitals in Sweden. Patients with available bone scans before treatment with 223Ra and at treatment discontinuation were eligible for the study. The aBSI was generated at baseline and at treatment discontinuation. The Spearman rank correlation was used to correlate aBSI with the baseline covariates: alkaline phosphatase (ALP) and prostate-specific antigen (PSA). The Cox proportional-hazards model and Kaplan-Meier curve were used to evaluate the association of covariates at baseline and their change at treatment discontinuation with overall survival (OS). The concordance index (C-index) was used to evaluate the discriminating strength of covariates in predicting OS. Results: Bone scan images at baseline were available from 156 patients, and 67 patients had both a baseline and a treatment discontinuation bone scan (median, 5 doses; interquartile range, 3-6 doses). Baseline aBSI (median, 4.5; interquartile range, 2.4-6.5) was moderately correlated with ALP (r = 0.60, P < 0.0001) and with PSA (r = 0.38, P = 0.003). Among baseline covariates, aBSI (P = 0.01) and ALP (P = 0.001) were significantly associated with OS, whereas PSA values were not (P = 0.059). After treatment discontinuation, 36% (24/67), 80% (54/67), and 13% (9/67) of patients demonstrated a decline in aBSI, ALP, and PSA, respectively. As a continuous variable, the relative change in aBSI after treatment, compared with baseline, was significantly associated with OS (P < 0.0001), with a C-index of 0.67. Median OS in patients with both aBSI and ALP decline (median, 134 wk) was significantly longer than in patients with ALP decline only (median, 77 wk; P = 0.029). Conclusion: Both aBSI at baseline and its change at treatment discontinuation were significant parameters associated with OS. The study warrants prospective validation of aBSI as a quantitative imaging response biomarker to predict OS in patients with mCRPC treated with 223Ra.
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| 3. |
- Puterman, C., et al.
(författare)
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A retrospective study assessing the accuracy of [18F]–fluorocholine PET/CT for primary staging of lymph node metastases in intermediate and high-risk prostate cancer patients undergoing robotic-assisted laparoscopic prostatectomy with extended lymph node dissection
- 2021
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Ingår i: Scandinavian Journal of Urology. - : Medical Journals Sweden AB. - 2168-1805 .- 2168-1813. ; 55:4, s. 293-297
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Tidskriftsartikel (refereegranskat)abstract
- Background: Previous studies have investigated [18F]-fluorocholine (FCH) positron emission tomography with computed tomography (PET/CT) in primary staging of men with intermediate or high-risk prostate cancer and have generally shown high specificity and poor sensitivity. FCH PET/CT is not recommended for the primary staging of metastases in the European guidelines for prostate cancer. However, it has been an option in the Swedish recommendations. Our aim was to assess PET/CT for primary staging of lymph node metastases before robotic-assisted laparoscopic prostatectomy (RALP) with extended pelvic lymph node dissection (ePLND) in patients with intermediate or high-risk prostate cancer. Method: We identified all men with prostate cancer undergoing FCH PET/CT for initial staging followed by RALP and ePLND at Skåne University Hospital between 2015 and 2018. The result from PET/CT scan was compared with pathology report as the reference method for calculation of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Results: In total, 252 patients were included in the final analysis. Among 85 patients with a suspicion of regional lymph node metastases on FCH PET/CT only 31 had pathology-proven metastases. The sensitivity was 43% (95% CI 0.32–0.55) and the specificity 70% (95% CI 0.63–0.76) for PET/CT to predict lymph node metastases. PPV was 36% and NPV was 75%. Risk group analyses showed similar results. Conclusion: Our study emphasizes the poor performance of FCH PET/CT to predict lymph node metastasis in intermediate and high-risk prostate cancer. The method should be replaced with newer radiopharmaceuticals, such as prostate-specific membrane antigen ligands. © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
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| 4. |
- Reza Felix, Mariana, et al.
(författare)
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Bone Scan Index as an Imaging Biomarker in Metastatic Castration-resistant Prostate Cancer : A Multicentre Study Based on Patients Treated with Abiraterone Acetate (Zytiga) in Clinical Practice
- 2016
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Ingår i: European Urology Focus. - : Elsevier BV. - 2405-4569. ; 2:5, s. 540-546
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Tidskriftsartikel (refereegranskat)abstract
- Background Abiraterone acetate (AA) prolongs survival in metastatic castration-resistant prostate cancer (mCRPC) patients. To measure treatment response accurately in bone, quantitative methods are needed. The Bone Scan Index (BSI), a prognostic imaging biomarker, reflects the tumour burden in bone as a percentage of the total skeletal mass calculated from bone scintigraphy. Objective To evaluate the value of BSI as a biomarker for outcome evaluation in mCRPC patients on treatment with AA according to clinical routine. Design, setting, and participants We retrospectively studied 104 mCRPC patients who received AA following disease progression after chemotherapy. All patients underwent whole-body bone scintigraphy before and during AA treatment. Baseline and follow-up BSI data were obtained using EXINI BoneBSI software (EXINI Diagnostics AB, Lund, Sweden). Outcome measurements and statistical analysis Associations between change in BSI, clinical parameters at follow-up, and overall survival (OS) were evaluated using the Cox proportional hazards regression models and Kaplan-Meier estimates. Discrimination between variables was assessed using the concordance index (C-index). Results and limitations Patients with an increase in BSI at follow-up of at most 0.30 (n = 54) had a significantly longer median survival time than those with an increase of BSI >0.30 (n = 50) (median: 16 vs 10 mo; p = 0.001). BSI change was also associated with OS in a multivariate Cox analysis including commonly used clinical parameters for prognosis (C-index = 0.7; hazard ratio: 1.1; p = 0.03). The retrospective design was a limitation. Conclusions Change in BSI was significantly associated with OS in mCRPC patients undergoing AA treatment following disease progression in a postchemotherapy setting. BSI may be a useful imaging biomarker for outcome evaluation in this group of patients, and it could be a valuable complementary tool in monitoring patients with mCRPC on second-line therapies. Patient summary Bone Scan Index (BSI) change is related to survival time in metastatic castration-resistant prostate cancer (mCRPC) patients on abiraterone acetate. BSI may be a valuable complementary decision-making tool supporting physicians monitoring patients with mCRPC on second-line therapies.
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