CT assessment of tumour response to treatment: comparison of linear, cross-sectional and volumetric measures of tumour size

Is it time to move from the Unidimensional RECIST 1.1 Response Assessment Criteria to a Volumetric Evaluation in the Present Era of Image-based Oncology? An Evaluation in Locally Advanced Head Neck Cancers Undergoing Treatment

AIMS

Tumour response assessments, as per Response Evaluation Criteria in Solid Tumours (RECIST 1.1), are based on the sum of diameters (SODs) of the primary tumour (longest diameter) and/or short axis diameter of lymph nodes. This study evaluates the response categorisation as per RECIST 1.1 vs Computed tomography (CT) based volumetric assessment of RECIST (proposed as vRECIST) in locally advanced head and neck cancers (LAHNCs) undergoing treatment.

MATERIAL AND METHODS

The pre-treatment SODs and CT estimated tumour volumes were recorded in 45 LAHNCs treated with radiotherapy (RT), chemoradiotherapy (CTRT) or thermochemoradiotherapy (HTCTRT). Tumour responses were assessed independently as per RECIST 1.1 and vRECIST by two radiation oncologists and grouped into complete response (CR), partial response (PR), stable disease (SD) or progressive disease (PD). These response groups were evaluated for the likely congruence of the two approaches, as categorised independently by these two observers.

RESULTS

All patients in stages III (n = 7), IVA (n = 16) and IVB (n = 22) were inoperable and had received either RT alone (n = 1), CTRT (n = 12) or HTCTRT (n = 32). Based on SODs criteria of RECIST 1.1, of the 45 patients, 5 and 40 were grouped as PR and SD by the first observer, while this changed to 34 and 10, respectively and 1 PD, with vRECIST (p < 0.001). Similarly, for the second observer, the 4 PR and 41 SD grouped using RECIST 1.1 were recategorised to 34 PR, 10 SD, and 1 PD by vRECIST (p < 0.001). Thus, a mismatch of 66.6% and 68.8%, respectively, was evident by observers first and second in categorising SD based on SODs of RECIST 1.1 vs PR on vRECIST.

CONCLUSIONS

Treatment responses in LAHNCs assessed using SODs resulted in significant uncertainties and failed to reflect actual volumetric changes in tumours during treatment. It is perhaps time to consider replacing the SODs of RECIST 1.1 with vRECIST for unequivocal tumour response categorisation in the present era of image-based oncology practice.

Hodgkin lymphoma: hypodense lesions in mediastinal masses

Hypodense volumes (HDV) in mediastinal masses can be visualized in a computed tomography scan in Hodgkin lymphoma. We analyzed staging CT scans of 1178 patients with mediastinal involvement from the EuroNet-PHL-C1 trial and explored correlations of HDV with patient characteristics, mediastinal tumor volume and progression-free survival. HDV occurred in 350 of 1178 patients (29.7%), typically in larger mediastinal volumes. There were different patterns in appearance with single lesions found in 243 patients (69.4%), multiple lesions in 107 patients (30.6%). Well delineated lesions were found in 248 cases (70.1%), diffuse lesions were seen in 102 cases (29.1%). Clinically, B symptoms occurred more often in patients with HDV (47.7% compared to 35.0% without HDV (p = 0.039)) and patients with HDV tended to be in higher risk groups. Inadequate overall early-18F-FDG-PET-response was strongly correlated with the occurrence of hypodense lesions (p < 0.001). Patients with total HDV > 40 ml (n = 80) had a 5 year PFS of 79.6% compared to 89.7% (p = 0.01) in patients with HDV < 40 ml or no HDV. This difference in PFS is not caused by treatment group alone. HDV is a common phenomenon in HL with mediastinal involvement.

A reduction in tumor volume exceeding 65% predicts a good histological response to neoadjuvant chemotherapy in patients with Ewing sarcoma

OBJECTIVE

No consensus exists for tumor volume response criteria in patients with Ewing sarcoma. This study aimed to identify an optimal cutoff for predicting a good histological response by analyzing tumor volume changes and tumor necrosis after neoadjuvant chemotherapy.

MATERIALS AND METHODS

We performed a retrospective analysis of 184 Ewing sarcoma patients, analyzing tumor volume changes before and after neoadjuvant chemotherapy. Patients were divided into two groups based on histological response: good (tumor necrosis ≥ 95%) and poor (tumor necrosis < 95%) responders. The receiver operating characteristic (ROC) area under the curve (AUC) method was used to determine the optimal thresholds for predicting the histological response. Additionally, the prognostic value of this cutoff for relapse-free survival was assessed.

RESULTS

Out of 184 patients, 83 (45%) had tumor necrosis ≥ 95%, while 101 (55%) had tumor necrosis < 95%. ROC analysis identified the optimal cutoff for a good histological response as over 65% tumor volume reduction (AUC = 0.69; p < 0.001). Patients with volume reduction of ≥ 65% had a higher likelihood of a good histological response than those with lesser reductions (p = 0.004; odds ratio = 2.61). Multivariable analysis indicated a correlation between poor histological response and reduced relapse-free survival (hazard ratio = 2.17; p = 0.01), while tumor volume reduction itself did not impact survival.

CONCLUSION

We reported that a tumor volume reduction of ≥ 65% was able to predict a good histological response in Ewing sarcoma patients. We recommend preoperative tumor volume assessment to identify patients at greater risk for poor histological response who could benefit from more intensive chemotherapy protocols or additional radiotherapy.

Semiautomated segmentation of hepatocellular carcinoma tumors with MRI using convolutional neural networks

OBJECTIVE

To assess the performance of convolutional neural networks (CNNs) for semiautomated segmentation of hepatocellular carcinoma (HCC) tumors on MRI.

METHODS

This retrospective single-center study included 292 patients (237 M/55F, mean age 61 years) with pathologically confirmed HCC between 08/2015 and 06/2019 and who underwent MRI before surgery. The dataset was randomly divided into training (n = 195), validation (n = 66), and test sets (n = 31). Volumes of interest (VOIs) were manually placed on index lesions by 3 independent radiologists on different sequences (T2-weighted imaging [WI], T1WI pre-and post-contrast on arterial [AP], portal venous [PVP], delayed [DP, 3 min post-contrast] and hepatobiliary phases [HBP, when using gadoxetate], and diffusion-weighted imaging [DWI]). Manual segmentation was used as ground truth to train and validate a CNN-based pipeline. For semiautomated segmentation of tumors, we selected a random pixel inside the VOI, and the CNN provided two outputs: single slice and volumetric outputs. Segmentation performance and inter-observer agreement were analyzed using the 3D Dice similarity coefficient (DSC).

RESULTS

A total of 261 HCCs were segmented on the training/validation sets, and 31 on the test set. The median lesion size was 3.0 cm (IQR 2.0-5.2 cm). Mean DSC (test set) varied depending on the MRI sequence with a range between 0.442 (ADC) and 0.778 (high b-value DWI) for single-slice segmentation; and between 0.305 (ADC) and 0.667 (T1WI pre) for volumetric-segmentation. Comparison between the two models showed better performance in single-slice segmentation, with statistical significance on T2WI, T1WI-PVP, DWI, and ADC. Inter-observer reproducibility of segmentation analysis showed a mean DSC of 0.71 in lesions between 1 and 2 cm, 0.85 in lesions between 2 and 5 cm, and 0.82 in lesions > 5 cm.

CONCLUSION

CNN models have fair to good performance for semiautomated HCC segmentation, depending on the sequence and tumor size, with better performance for the single-slice approach. Refinement of volumetric approaches is needed in future studies.

KEY POINTS

• Semiautomated single-slice and volumetric segmentation using convolutional neural networks (CNNs) models provided fair to good performance for hepatocellular carcinoma segmentation on MRI. • CNN models' performance for HCC segmentation accuracy depends on the MRI sequence and tumor size, with the best results on diffusion-weighted imaging and T1-weighted imaging pre-contrast, and for larger lesions.

Computed tomography of the spleen in chickens

The avian spleen is an important immune organ in birds and its size can be used as an index of immune system responses in different conditions. Based on the lack of knowledge in computed tomography of the spleen in chickens, the present study was conducted to assess the inter-and intraobserver reliability in the measurement of the spleen dimensions and attenuation, as well as the feasibility of utilization of these measurements as a predictor of different diseases. For these purposes, the spleens of 47 chickens were included in the study. Two observers measured the dimensions and attenuations of the spleen, which were finally compared with the clinical diagnosis. The results showed an excellent interobserver reliability in the length, width, and height of the spleen (ICC: 0.944, 0.906, and 0.938, retrospectively), and a good interobserver reliability was observed during the evaluation of the average Hounsfield units of the spleen (ICC: 0.818). The intraobserver reliability was excellent in all the measurements (ICC > 0.940). Additionally, no statistical differences were detected in the spleen size and attenuation between the normal and diseased groups. Based on the present results, the computed tomographic measurements of the spleen could not predict the clinical diseases of the chickens; however, the low rates of the inter- and intraobserver variability suggest the reliable utilization of these computed tomographic measurements in routine clinical application and follow-up examinations.

Assessment of immunotherapy response in intracranial malignancy using semi-automatic segmentation on magnetic resonance images

Objective

To explore multi-aspect radiologic assessment of immunotherapy response in intracranial malignancies based on a semi-automatic segmentation technique, and to explore volumetric thresholds with good performance according to RECIST 1.1 thresholds.

Methods

Patients diagnosed with intracranial malignancies and treated with immunotherapy were included retrospectively. In all MR images, target lesions were measured using a semi-automatic segmentation technique that could intelligently generate visual diagrams including RECIST 1.1, total volume, and max. 3D diameter. The changes in parameters were calculated for each patient after immunotherapy. The ROC curve was used to analyze the sensitivity and specificity of the size change of the legion. This was useful to find new volumetric thresholds with better efficiency in response assessment. The changes in total volume were assessed by conventional volumetric thresholds, while RECIST 1.1 thresholds were for the max. 3D diameter. A chi-square test was used to compare the concordance and diagnostic correlation between the response assessment results of the three criteria.

Results

A total of 20 cases (average age, 58 years; range, 23 to 84 years) and 58 follow-up MR examinations after immunotherapy were included in the analysis. The P-value of the chi-square test between RECIST 1.1 and total volume is 0 (P <0.05), same as that in RECIST 1.1 and max. 3D diameter. The kappa value of the former two was 0.775, and the kappa value for the latter two was 0.742. The above results indicate a significant correlation and good concordance for all three criteria. In addition, we also found that the volumetric assessment had the best sensitivity and specificity for the immunotherapy response in intracranial malignancies, with a PR threshold of -64.9% and a PD threshold of 21.4%.

Conclusions

Radiologic assessment of immunotherapy response in intracranial malignancy can be performed by multiple criteria based on semi-automatic segmentation technique on MR images, such as total volume, max. 3D diameter and RECIST 1.1. In addition, new volumetric thresholds with good sensitivity and specificity were found by volumetric assessment.

Intratumoral injection of holmium-166 microspheres as neoadjuvant therapy of soft tissue sarcomas in dogs

INTRODUCTION

Minimally invasive microbrachytherapy is in development to treat solid tumors by intratumoral injection of (radioactive) holmium-166 (¹⁶⁶Ho) microspheres (MS). A high local dose can be administered with minimal damage to surrounding tissue because of the short soft tissue penetration depth of ¹⁶⁶Ho beta radiation. We aimed to prospectively evaluate the safety and efficacy of ¹⁶⁶Ho microbrachytherapy in client-owned canine patients with soft tissue sarcomas (STS).

METHODS

We included seven dogs with STS not suitable for local excision due to tumor size and/or location. ¹⁶⁶HoMS were suspended in a carrier fluid and multiple needle-injections were performed in predetermined tumor segments to maximize tumor coverage. Tumor response was evaluated using 3D caliper and CT measurements. Follow-up further included monitoring for potential side effects and registration of subsequent treatments and survival, until at least two years after treatment.

RESULTS

Delivered radioactive doses ranged from 70 to 969 Gy resulting in a mean tumor volume reduction of 49.0 ± 21.3% after 33 ± 25 days. Treatment-related side effects consisted of local necrosis (n = 1) and ulceration of the skin covering the tumor (n = 1), which resolved with basic wound care, and surgical excision of residual tumor, respectively. Residual tumor was surgically resected in six patients after 22-93 days. After a mean follow-up of 1,005 days, four patients were alive, two patients were euthanized because of unrelated causes, and one patient was euthanized because of disease progression after the owner(s) declined subsequent surgical treatment.

CONCLUSION

¹⁶⁶Ho microbrachytherapy was a safe and effective neoadjuvant treatment option for canine patients with STS.

Non-inferiority of a non-gadolinium-enhanced magnetic resonance imaging follow-up protocol for isolated optic pathway gliomas

BACKGROUND

Pediatric patients with optic pathway gliomas (OPGs) typically undergo a large number of follow-up MRI brain exams with gadolinium-based contrast media (GBCM), which have been associated with gadolinium tissue retention. Therefore, careful consideration of GBCM use in these children is warranted.

OBJECTIVE

To investigate whether GBCM is necessary for OPG MR imaging response assessment using a blinded, non-inferiority, multi-reader study.

MATERIALS AND METHODS

We identified children with OPG and either stable disease or change in tumor size on MRI using a regional cancer registry serving the U.S. Pacific Northwest. For each child, the two relevant, consecutive MRI studies were anonymized and standardized into two imaging sets excluding or including GBCM-enhanced images. Exam pairs were compiled from 42 children with isolated OPG (19 with neurofibromatosis type 1), from a population of 106 children with OPG. We included 28 exam pairs in which there was a change in size between exams. Seven pediatric radiologists measured tumor sizes during three blinded sessions, spaced by at least 1 week. The first measuring session excluded GBCM-enhanced sequences; the others did not. The primary endpoint was intra-reader agreement for ≥ 25% change in axial cross-product measurement, using a 12% non-inferiority threshold.

RESULTS

Analysis demonstrated an overall 1.2% difference (95% confidence interval, -3.2% to 5.5%) for intra-reader agreement using a non-GBCM-enhanced protocol and background variability.

CONCLUSION

A non-GBCM-enhanced protocol was non-inferior to a GBCM-enhanced protocol for assessing change in size of isolated OPGs on follow-up MRI exams.

Artificial intelligence in assessment of hepatocellular carcinoma treatment response

Artificial Intelligence (AI) continues to shape the practice of radiology, with imaging of hepatocellular carcinoma (HCC) being of no exception. This article prepared by members of the LI-RADS Treatment Response (TR LI-RADS) work group and associates, presents recent trends in the utility of AI applications for the volumetric evaluation and assessment of HCC treatment response. Various topics including radiomics, prognostic imaging findings, and locoregional therapy (LRT) specific issues will be discussed in the framework of HCC treatment response classification systems with focus on the Liver Reporting and Data System treatment response algorithm (LI-RADS TRA).

Comparison of CT Volumetry and RECIST to Predict the Treatment Response and Overall Survival in Gastric Cancer Liver Metastases

Purpose

The aim of this study was to compare the diameter and volume of liver metastases on CT images in relation to overall survival and tumor response in patients with gastric cancer liver metastases (GCLM) treated with chemotherapy.

Materials and Methods

We recruited 43 patients with GCLM who underwent chemotherapy as a first-line treatment. We performed a three-dimensional quantification of the metastases for each patient. An independent survival analysis using the Response Evaluation Criteria in Solid Tumors (RECIST) was performed and compared to volumetric measurements. Overall survival was evaluated using Kaplan-Meier analysis and compared using Cox proportional hazard ratios following univariate analyses.

Results

When patients were classified as responders or non-responders based on volumetric criteria, the median overall survival was 23.6 months [95% confidence interval (CI), 8.63–38.57] and 7.6 months (95% CI, 3.78–11.42), respectively (p = 0.039). The volumetric analysis and RECIST of the non-progressing and progressing groups showed similar results based on the Kaplan-Meier method (p = 0.006) and the Cox proportional hazard model (p = 0.008).

Conclusion

Volumetric assessment of liver metastases could be an alternative predictor of overall survival for patients with GCLM treated with chemotherapy.

Objective response rate assessment in oncology: Current situation and future expectations

The tumor objective response rate (ORR) is an important parameter to demonstrate the efficacy of a treatment in oncology. The ORR is valuable for clinical decision making in routine practice and a significant end-point for reporting the results of clinical trials. World Health Organization and Response Evaluation Criteria in Solid Tumors (RECIST) are anatomic response criteria developed mainly for cytotoxic chemotherapy. These criteria are based on the visual assessment of tumor size in morphological images provided by computed tomography (CT) or magnetic resonance imaging. Anatomic response criteria may not be optimal for biologic agents, some disease sites, and some regional therapies. Consequently, modifications of RECIST, Choi criteria and Morphologic response criteria were developed based on the concept of the evaluation of viable tumors. Despite its limitations, RECIST v1.1 is validated in prospective studies, is widely accepted by regulatory agencies and has recently shown good performance for targeted cancer agents. Finally, some alternatives of RECIST were developed as immune-specific response criteria for checkpoint inhibitors. Immune RECIST criteria are based essentially on defining true progressive disease after a confirmatory imaging. Some graphical methods may be useful to show longitudinal change in the tumor burden over time. Tumor tissue is a tridimensional heterogenous mass, and tumor shrinkage is not always symmetrical; thus, metabolic response assessments using positron emission tomography (PET) or PET/CT may reflect the viability of cancer cells or functional changes evolving after anticancer treatments. The metabolic response can show the benefit of a treatment earlier than anatomic shrinkage, possibly preventing delays in drug approval. Computer-assisted automated volumetric assessments, quantitative multimodality imaging in radiology, new tracers in nuclear medicine and finally artificial intelligence have great potential in future evaluations.

AI-based applications in hybrid imaging: how to build smart and truly multi-parametric decision models for radiomics

INTRODUCTION

The quantitative imaging features (radiomics) that can be obtained from the different modalities of current-generation hybrid imaging can give complementary information with regard to the tumour environment, as they measure different morphologic and functional imaging properties. These multi-parametric image descriptors can be combined with artificial intelligence applications into predictive models. It is now the time for hybrid PET/CT and PET/MRI to take the advantage offered by radiomics to assess the added clinical benefit of using multi-parametric models for the personalized diagnosis and prognosis of different disease phenotypes.

OBJECTIVE

The aim of the paper is to provide an overview of current challenges and available solutions to translate radiomics into hybrid PET-CT and PET-MRI imaging for a smart and truly multi-parametric decision model.

Computed tomography volumetry of esophageal cancer - the role of semiautomatic assessment

Background

The clinical and research value of Computed Tomography (CT) volumetry of esophageal cancer tumor size remains controversial. Development in CT technique and image analysis has made CT volumetry less cumbersome and it has gained renewed attention. The aim of this study was to assess esophageal tumor volume by semi-automatic measurements as compared to manual.

Methods

A total of 23 esophageal cancer patients (median age 65, range 51–71), undergoing CT in the portal-venous phase for tumor staging, were retrospectively included between 2007 and 2012. One radiology resident and one consultant radiologist measured the tumor volume by semiautomatic segmentation and manual segmentation. Reproducibility of the respective measurements was assessed by intraclass correlation coefficients (ICC) and by average deviation from mean.

Results

Mean tumor volume was 46 ml (range 5-137 ml) using manual segmentation and 42 ml (range 3-111 ml) using semiautomatic segmentation. Semiautomatic measurement provided better inter-observer agreement than traditional manual segmentation. The ICC was significantly higher for semiautomatic segmentation in comparison to manual segmentation (0.86, 0.56, p < 0.01). The average absolute percentage difference from mean was reduced from 24 to 14% (p < 0.001) when using semiautomatic segmentation.

Conclusions

Semiautomatic analysis outperforms manual analysis for assessment of esophageal tumor volume, improving reproducibility.

Quantitative and qualitative analysis of bone flap resorption in patients undergoing cranioplasty after decompressive craniectomy

OBJECTIVE: Autologous bone cranioplasty after decompressive craniectomy entails a notable burden of difficult postoperative complications, such as infection and bone flap resorption (BFR), leading to mechanical failure. The prevalence and significance of asymptomatic BFR is currently unclear. The aim of this study was to radiologically monitor the long-term bone flap survival and bone quality change in patients undergoing autologous cranioplasty. METHODS: The authors identified all 45 patients who underwent autologous cranioplasty at Oulu University Hospital, Finland, between January 2004 and December 2014. Using perioperative and follow-up CT scans, the volumes and radiodensities of the intact bone flap prior to surgery and at follow-up were calculated. Relative changes in bone flap volume and radiodensity were then determined to assess cranioplasty survival. Sufficient CT scans were obtainable from 41 (91.1%) of the 45 patients. RESULTS: The 41 patients were followed up for a median duration of 3.79 years (25th and 75th percentiles = 1.55 and 6.66). Thirty-seven (90.2%) of the 41 patients had some degree of BFR and 13 (31.7%) had a remaining bone flap volume of less than 80%. Patients younger than 30 years of age had a mean decrease of 15.8% in bone flap volume compared with the rest of the cohort. Bone flap volume was not found to decrease linearly with the passing of time, however. The effects of lifestyle factors and comorbidities on BFR were nonsignificant. CONCLUSIONS: In this study BFR was a very common phenomenon, occurring at least to some degree in 90% of the patients. Decreases in bone volume were especially prominent in patients younger than 30 years of age. Because the progression of resorption during follow-up was nonlinear, routine follow-up CT scans appear unnecessary in monitoring the progression of BFR; instead, clinical follow-up with mechanical stability assessment is advised. Partial resorption is most likely a normal physiological phenomenon during the bone revitalization process.

Feasibility of CT radiomics to predict treatment response of individual liver metastases in esophagogastric cancer patients

In this study we investigate a CT radiomics approach to predict response to chemotherapy of individual liver metastases in patients with esophagogastric cancer (EGC). In eighteen patients with metastatic EGC treated with chemotherapy, all liver metastases were manually delineated in 3D on the pre-treatment and evaluation CT. From the pre-treatment CT scans 370 radiomics features were extracted per lesion. Random forest (RF) models were generated to discriminate partial responding (PR, >65% volume decrease, including 100% volume decrease), and complete remission (CR, only 100% volume decrease) lesions from other lesions. RF-models were build using a leave one out strategy where all lesions of a single patient were removed from the dataset and used as validation set for a model trained on the lesions of the remaining patients. This process was repeated for all patients, resulting in 18 trained models and one validation set for both the PR and CR datasets. Model performance was evaluated by receiver operating characteristics with corresponding area under the curve (AUC). In total 196 liver metastases were delineated on the pre-treatment CT, of which 99 (51%) lesions showed a decrease in size of more than 65% (PR). From the PR set a total of 47 (47% of RL, 24% of initial) lesions were no longer detected in CT scan 2 (CR). The RF-model for PR lesions showed an average training AUC of 0.79 (range: 0.74-0.83) and 0.65 (95% ci: 0.57-0.73) for the combined validation set. The RF-model for CR lesions had an average training AUC of 0.87 (range: 0.83-0.90) and 0.79 (95% ci 0.72-0.87) for the validation set. Our findings show that individual response of liver metastases varies greatly within and between patients. A CT radiomics approach shows potential in discriminating responding from non-responding liver metastases based on the pre-treatment CT scan, although further validation in an independent patient cohort is needed to validate these findings.

[Base of the skull meningioma: Efficacy, clinical tolerance and radiological evaluation after radiotherapy]

Skull base meningioma leads to functional disturbances, which can significantly alter the quality of life. The optimal management of these lesions, whose goals are neurological preservation and tumour local control, is not yet clearly established. It is widely recognized that the goal of a radical excision should be abandoned despite the advances in the field of microsurgery of skull base lesions. Although less morbid, partial tumour excision would be associated with increased risk of local tumour recurrence. Although discussed both exclusive and adjuvant have proven to be highly successful in terms of clinical improvement and local control. Various radiation techniques have demonstrated their efficacy in the management of this pathology. However, high rates of clinical improvement are in contrast with low rates of radiological improvement. The notion of clinical and radiological dissociation appeared. However, in most of these studies, the analysis of the radiological response could be subject of legitimate criticism. This work proposes to review the local control, the efficacy and the clinical tolerance and the radiological response of the various radiation techniques for the meningioma of the base of the skull and to demonstrate the interest of quantitative volumetric analyses in the follow-up of meningioma after radiotherapy.

Comparison of 2D (RANO) and volumetric methods for assessment of recurrent glioblastoma treated with bevacizumab-a report from the BELOB trial

Background

The current method for assessing progressive disease (PD) in glioblastoma is according to the Response Assessment in Neuro-Oncology (RANO) criteria. Bevacizumab-treated patients may show pseudo-response on postcontrast T1-weighted (T1w) MRI, and a more infiltrative non-enhancing growth pattern on T2w/fluid attenuated inversion recovery (FLAIR) images. We investigated whether the RANO criteria remain the method of choice for assessing bevacizumab-treated recurrent glioblastoma when compared with various volumetric methods.

Methods

Patients with assessable MRI data from the BELOB trial (n = 148) were included. Patients were treated with bevacizumab, lomustine, or both. At first and second radiological follow-up (6 and 12 wk), PD was determined using the 2D RANO criteria and various volumetric methods based on enhancing tumor only and enhancing plus non-enhancing tumor. Differences in overall survival (OS) between PD and non-PD patients were assessed with the log-rank test and a Cox model. Hazard ratios (HRs) and their 95% CIs were determined.

Results

For all patients together, all methods (except subtraction of non-enhancing from enhancing volume at first follow-up) showed significant differences in OS between PD and non-PD patients (P < .001). The largest risk increase for death in case of PD at both first and second follow-up was found with the RANO criteria: HR = 2.81 (95% CI, 1.92-4.10) and HR = 2.80 (95% CI, 1.75-4.49), respectively. In the bevacizumab-treated patients, all methods assessed showed significant differences in OS between PD and non-PD patients. There were no significant differences between methods.

Conclusions

In the first 12 weeks, volumetric methods did not provide significant improvement over the RANO criteria as a posttreatment prognostic marker.

Therapeutic response assessment using 3D ultrasound for hepatic metastasis from colorectal cancer: Application of a personalized, 3D-printed tumor model using CT images

Background & aims

To evaluate accuracy and reliability of three-dimensional ultrasound (3D US) for response evaluation of hepatic metastasis from colorectal cancer (CRC) using a personalized 3D-printed tumor model.

Methods

Twenty patients with liver metastasis from CRC who underwent baseline and after chemotherapy CT, were retrospectively included. Personalized 3D-printed tumor models using CT were fabricated. Two radiologists measured volume of each 3D printing model using 3D US. With CT as a reference, we compared difference between CT and US tumor volume. The response evaluation was based on Response Evaluation Criteria in Solid Tumors (RECIST) criteria.

Results

3D US tumor volume showed no significant difference from CT volume (7.18 ± 5.44 mL, 8.31 ± 6.32 mL vs 7.42 ± 5.76 mL in CT, p>0.05). 3D US provided a high correlation coefficient with CT (r = 0.953, r = 0.97) as well as a high inter-observer intraclass correlation (0.978; 0.958–0.988). Regarding response, 3D US was in agreement with CT in 17 and 18 out of 20 patients for observer 1 and 2 with excellent agreement (κ = 0.961).

Conclusions

3D US tumor volume using a personalized 3D-printed model is an accurate and reliable method for the response evaluation in comparison with CT tumor volume.

Interventional Oncology in Hepatocellular Carcinoma: Progress Through Innovation

The clinical management of hepatocellular carcinoma has evolved greatly in the last decade mostly through recent technical innovations. In particular, the application of cutting-edge image guidance has led to minimally invasive solutions for complex clinical problems and rapid advances in the field of interventional oncology. Many image-guided therapies, such as transarterial chemoembolization and radiofrequency ablation, have meanwhile been fully integrated into interdisciplinary clinical practice, whereas others are currently being investigated. This review summarizes and evaluates the most relevant completed and ongoing clinical trials, provides a synopsis of recent innovations in the field of intraprocedural imaging and tumor response assessment, and offers an outlook on new technologies, such as radiopaque embolic materials. In addition, combination therapies consisting of locoregional therapies and systemic molecular targeted agents (e.g., sorafenib) remain of major interest to the field and are also discussed. Finally, we address the many substantial advances in immune response pathways that have been related to the systemic effects of locoregional therapies. Knowledge of these new developments is crucial as they continue to shape the future of cancer treatment, further establishing interventional oncology along with surgical, medical, and radiation oncology as the fourth pillar of cancer care.

Prognostic value of tumor volume for patients with advanced lung cancer treated with chemotherapy

BACKGROUND AND OBJECTIVE

We aim to develop a reference system utilizing computed tomography to calculate changes in tumor volume of lung cancer patients after chemotherapy to assist physicians in clinical treatment and evaluation.

METHODS

Image processing techniques were used to analyze the computed tomography of lung cancer, locate the tumor, and calculate the tumor volume. The medical indicator was then evaluated and analyzed. We examined the correlation between reduced tumor volume and survival duration of 88 patients after chemotherapy at Tri-Service General Hospital, Taiwan. The innovative survival prediction index was obtained by four statistical methods: receiver operating characteristic curve, Youden index, Kaplan-Meier method, and log rank test.

RESULTS

From the image processing techniques, tumor volume from each patient were obtained within an average of 7.25 seconds. The proposed method was shown to achieve rapid positioning of lung tumors and volume reconstruction with an estimation error of 1.92% when calibrated with an irregularly shaped stone. In medical indicator evaluation and analysis, the area below the receiver operating characteristic curve is greater than 0.8, indicating good predictability of the medical index used herein. The Youden index spotted the best cut-off point of volume, and the correlation between the volume's cut-off point and survival time was confirmed again by Kaplan-Meier and log rank test. The p-values were all less than 0.05, presenting a high degree of correlation between the two, indicating that this medical indicator is highly reliable.

CONCLUSIONS

The proposed techniques can automatically find the location of tumors in the lung, reconstruct the volume, and calculate changes in volume before and after treatment, thus obtaining an innovative survival prediction index. This will help facilitate early and accurate predictions of disease outcomes during the course of therapy, and categorize patient stratification into risk groups for more efficient therapies.

New concepts in embolotherapy of HCC

Hepatocellular carcinoma (HCC) is the second most common cause of cancer-related deaths worldwide with rapidly growing incidence rates in the USA and Europe. Despite improving surveillance programs, most patients are diagnosed at intermediate to advanced stages and are no longer amenable to curative therapies, such as ablation, surgical resection and liver transplantation. For such patients, catheter-based image-guided embolotherapies such as transarterial chemoembolization (TACE) represent the standard of care and mainstay therapy, as recommended and endorsed by a variety of national guidelines and staging systems. The main benefit of these therapies is explained by the preferentially arterial blood supply of liver tumors, which allows to deliver the anticancer therapy directly to the tumor-feeding artery while sparing the healthy hepatic tissue mainly supplied by the portal vein. The tool box of an interventional oncologist contains several different variants of transarterial treatment modalities. Ever since the first TACE more than 30 years ago, these techniques have been progressively refined, both with respect to drug delivery materials and with respect to angiographic micro-catheter and image-guidance technology, thus substantially improving therapeutic outcomes of HCC. This review will summarize the fundamental principles, technical and clinical data on the application of different embolotherapies, such as bland transarterial embolization, Lipiodol-based conventional transarterial chemoembolization as well as TACE with drug-eluting beads (DEB-TACE). Clinical data on ⁹⁰Yttrium radioembolization as an emerging alternative, mostly applied for niche indications such as HCC with portal vein invasion, will be discussed. Furthermore, we will summarize the principle of HCC staging, patient allocation and response assessment in the setting of HCC embolotherapy. In addition, we will evaluate the role of cone-beam computed tomography as a novel intra-procedural image-guidance technology. Finally, this review will touch on new technical developments such as radiopaque, imageable DEBs and the rationale and role of combined systemic and locoregional therapies, mostly in combination with Sorafenib.

A human clinical trial using ultrasound and microbubbles to enhance gemcitabine treatment of inoperable pancreatic cancer

BACKGROUND

The primary aim of our study was to evaluate the safety and potential toxicity of gemcitabine combined with microbubbles under sonication in inoperable pancreatic cancer patients. The secondary aim was to evaluate a novel image-guided microbubble-based therapy, based on commercially available technology, towards improving chemotherapeutic efficacy, preserving patient performance status, and prolonging survival.

METHODS

Ten patients were enrolled and treated in this Phase I clinical trial. Gemcitabine was infused intravenously over 30min. Subsequently, patients were treated using a commercial clinical ultrasound scanner for 31.5min. SonoVue® was injected intravenously (0.5ml followed by 5ml saline every 3.5min) during the ultrasound treatment with the aim of inducing sonoporation, thus enhancing therapeutic efficacy.

RESULTS

The combined therapeutic regimen did not induce any additional toxicity or increased frequency of side effects when compared to gemcitabine chemotherapy alone (historical controls). Combination treated patients (n=10) tolerated an increased number of gemcitabine cycles compared with historical controls (n=63 patients; average of 8.3±6.0cycles, versus 13.8±5.6cycles, p=0.008, unpaired t-test). In five patients, the maximum tumour diameter was decreased from the first to last treatment. The median survival in our patients (n=10) was also increased from 8.9months to 17.6months (p=0.011).

CONCLUSIONS

It is possible to combine ultrasound, microbubbles, and chemotherapy in a clinical setting using commercially available equipment with no additional toxicities. This combined treatment may improve the clinical efficacy of gemcitabine, prolong the quality of life, and extend survival in patients with pancreatic ductal adenocarcinoma.

ERCC1 Expression-Based Randomized Phase II Study of Gemcitabine/Cisplatin Versus Irinotecan/Cisplatin in Patients with Advanced Non-small Cell Lung Cancer

Purpose

We evaluated the clinical utility of excision repair cross-complementation group 1 (ERCC1) expression as a predictive biomarker for platinum-based chemotherapy in advanced non-small cell lung cancer (NSCLC).

Materials and Methods

Eligible patients were randomly assigned to the GP (gemcitabine 1,250 mg/m² on days 1 and 8, and cisplatin 75 mg/m² on day 1 every 3 weeks) or IP (irinotecan 65 mg/m² and cisplatin 30 mg/m² on days 1 and 8 every 3 weeks) arm. The primary goal of this study was to compare the response rate (RR) of the GP and IP arms according to the ERCC1 expression level.

Results

A total of 279 patients were randomly assigned to the GP (n=139) and IP (n=140) arms, among which 63% were ERCC1-positive and 268 patients were assessable for the RR. The GP and IP arms did not differ significantly with respect to the RR (29.8% vs. 27.0%, respectively; p=0.082), median progression-free survival (PFS; 4.5 months vs. 3.9 months, respectively; p=0.117), and overall survival (OS; 16.5 months vs. 16.7 months, respectively; p=0.313). When comparing the efficacy between the ERCC1-positive and ERCC1-negative groups, there was no significant difference in the RR (GP, 28.2% vs. 32.6%, respectively, p=0.509; IP, 30.2% vs. 21.6%, respectively, p=0.536), median PFS (GP, 4.6 months vs. 5.0 months, respectively, p=0.506; IP, 3.9 months vs. 3.7 months, respectively, p=0.748), or median OS (GP, 18.6 months vs. 11.9 months, respectively, p=0.070; IP, 17.5 months vs. 14.0 months, respectively, p=0.821).

Conclusion

Immunohistochemical analysis of the ERCC1 expression level did not differentiate the efficacy of platinum-based chemotherapy in advanced NSCLC.

PNA clamping-assisted fluorescence melting curve analysis for detecting EGFR and KRAS mutations in the circulating tumor DNA of patients with advanced non-small cell lung cancer

Background

Circulating cell-free DNA (cfDNA) is emerging as a surrogate sample type for mutation analyses. To improve the clinical utility of cfDNA, we developed a sensitive peptide nucleic acid (PNA)-based method for analyzing EGFR and KRAS mutations in the plasma cfDNA of patients with advanced non-small cell lung cancer (NSCLC).

Methods

Baseline tissue and plasma samples were collected from treatment-naïve advanced NSCLC patients participated in a randomized phase II study, which was registered with ClinicalTrials.gov at Feb. 2009 (NCT01003964). EGFR and KRAS mutations in the plasma cfDNA were analyzed retrospectively using a PNA clamping-assisted fluorescence melting curve analysis. The results were compared with those obtained from tissue analysis performed using the direct sequencing. Exploratory analyses were performed to determine survival predicted by the plasma and tissue mutation status.

Results

Mutation analyses in matched tissue and plasma samples were available for 194 patients for EGFR and 135 patients for KRAS. The mutation concordance rates were 82.0 % (95 % confidence interval [CI], 76.5–87.4) for EGFR and 85.9 % (95 % CI, 80.1–91.8) for KRAS. The plasma EGFR mutation test sensitivity and specificity were 66.7 % (95 % CI, 60.0–73.3) and 87.4 % (95 % CI, 82.7–92.1), respectively, and the plasma KRAS mutation test sensitivity and specificity were 50.0 % (95 % CI, 41.6–58.4) and 89.4 % (95 % CI, 84.2–94.6), respectively. The predictive value of the plasma EGFR and KRAS mutation status with respect to survival was comparable with that of the tissue mutation status.

Conclusions

These data suggest that plasma EGFR and KRAS mutations can be analyzed using PNA-based real-time PCR methods and used as an alternative to tumor genotyping for NSCLC patients when tumor tissue is not available.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2678-2) contains supplementary material, which is available to authorized users.

Dose-Volume Response Relationship for Brain Metastases Treated with Frameless Single-Fraction Linear Accelerator-Based Stereotactic Radiosurgery

BACKGROUND

Our aim was to identify a dose-volume response relationship for brain metastases treated with frameless stereotactic radiosurgery (SRS).

METHODS

We reviewed patients who underwent frameless single-fraction linear accelerator SRS for brain metastases between 2007 and 2013 from an institutional database. Proportional hazards modeling was used to identify predictors of outcome. A ratio of maximum lesion dose per mm-diameter (Gy/mm) was constructed to establish a dose-volume relationship.

RESULTS

There were 316 metastases evaluated in 121 patients (2 - 33 mm in the largest diameter). The median peripheral dose was 18.0 Gy (range: 10.0 - 24.0 Gy). Local control was 84.8% for all lesions and was affected by location, peripheral dose, maximum dose, and lesion size (p values < 0.050). A dose-volume response relationship was constructed using the maximum dose and lesion size. A unit increase in Gy/mm was associated with decreased local failure (p = 0.005). Local control of 80%, 85%, and 90% corresponded to maximum doses per millimeter of 1.67 Gy/mm, 2.86 Gy/mm, and 4.4 Gy/mm, respectively. Toxicity was uncommon and only 1.0% of lesions developed radionecrosis requiring surgery.

CONCLUSIONS

For brain metastases less than 3 cm, a dose-volume response relationship exists between maximum radiosurgical dose and lesion size, which is predictive of local control.

Three-dimensional Radiologic Assessment of Chemotherapy Response in Ewing Sarcoma Can Be Used to Predict Clinical Outcome

Purpose To compare the agreement of three-dimensional (3D) tumor measurements for therapeutic response assessment of Ewing sarcoma according to the Children's Oncology Group (COG) criteria, one-dimensional (1D) Response Evaluation Criteria in Solid Tumors (RECIST), and two-dimensional (2D) measurements defined by the World Health Organization (WHO) with tumor volume measurements as the standard of reference and to determine which method correlates best with clinical outcomes. Materials and Methods This retrospective study was approved by the institutional review board of three institutions. Seventy-four patients (mean age ± standard deviation, 14.5 years ± 6.5) with newly diagnosed Ewing sarcoma treated at three medical centers were evaluated. Primary tumor size was assessed on pre- and posttreatment magnetic resonance images according to 1D RECIST, 2D WHO, and 3D COG measurements. Tumor responses were compared with the standard of reference (tumor volume) on the basis of RECIST, COG, and WHO therapeutic response thresholds. Agreement between the percentage reduction measurements of the methods was assessed with concordance correlation, Bland-Altman analysis, and Spearman rank correlation. Agreement between therapeutic responses was assessed with Kendall tau and unweighted κ statistics. Tumor responses were compared with patient survival by using the log-rank test, Kaplan-Meier plots, and Cox regression. Results Agreement with the reference standard was significantly better for 3D measurement than for 1D and 2D measurements on the basis of RECIST and COG therapeutic response thresholds (concordance correlation of 0.41, 0.72, and 0.84 for 1D, 2D, and 3D measurements, respectively; P < .0001). Comparison of overall survival of responders and nonresponders demonstrated P values of .4133, .0112, .0032, and .0027 for 1D, 2D, 3D, and volume measurements, respectively, indicating that higher dimensional measurements were significantly better predictors of overall survival. Conclusion The 3D tumor measurements according to COG are better predictors of therapeutic response of Ewing sarcoma than 1D RECIST or 2D WHO measurements and show a significantly higher correlation with clinical outcomes. (©) RSNA, 2016 Online supplemental material is available for this article.

Evaluation of a cloud-based local-read paradigm for imaging evaluations in oncology clinical trials for lung cancer

Background

Although tumor response evaluated with radiological imaging is frequently used as a primary endpoint in clinical trials, it is difficult to obtain precise results because of inter- and intra-observer differences.

Purpose

To evaluate usefulness of a cloud-based local-read paradigm implementing software solutions that standardize imaging evaluations among international investigator sites for clinical trials of lung cancer.

Material and Methods

Two studies were performed: KUMO I and KUMO I Extension. KUMO I was a pilot study aiming at demonstrating the feasibility of cloud implementation and identifying issues regarding variability of evaluations among sites. Chest CT scans at three time-points from baseline to progression, from 10 patients with lung cancer who were treated with EGFR tyrosine kinase inhibitors, were evaluated independently by two oncologists (Japan) and one radiologist (France), through a cloud-based software solution. The KUMO I Extension was performed based on the results of KUMO I.

Results

KUMO I showed discordance rates of 40% for target lesion selection, 70% for overall response at the first time-point, and 60% for overall response at the second time-point. Since the main reason for the discordance was differences in the selection of target lesions, KUMO I Extension added a cloud-based quality control service to achieve a consensus on the selection of target lesions, resulting in an improved rate of agreement of response evaluations.

Conclusion

The study shows the feasibility of imaging evaluations at investigator sites, based on cloud services for clinical studies involving multiple international sites. This system offers a step forward in standardizing evaluations of images among widely dispersed sites.

Quantitative Evaluation of Local Control and Wound Healing Following Surgery and Stereotactic Spine Radiosurgery for Spine Tumors

OBJECTIVE

The present study evaluated the optimal measuring criteria to assess spinal tumor response to surgery followed by stereotactic spine radiosurgery (SRS) and reports the local control and wound complication rates following combined multimodality treatment.

METHODS AND MATERIALS

Prospectively collected patient information was retrospectively reviewed to identify patients treated with spine surgery followed by SRS. Tumor sizes and volumetric assessment were formally measured. Local control status was defined according to World Health Organization (WHO, bidimensional), RECIST (unidimensional), or volumetric size change. Statistical comparative assessments of tumor measurements were performed.

RESULTS

Twenty-two patients were eligible for evaluation after having undergone surgery followed by single-fraction SRS within a 2-month period. Seventeen had follow-up magnetic resonance imaging (MRI) with a mean patient follow-up of 12.59 months (range 3-36 months). None developed wound complication after radiation therapy (95% lower confidence bound 13%). Two patients had clinical recurrence while 15 of 17 achieved local control (88.3%). A test of marginal homogeneity for RECIST versus WHO was not statistically significant, P = 1.0 suggesting similar response classifications with both systems. Spearman correlations among 1) volumetric assessment, 2) bidimensional size, and 3) unidimensional size were significant for all groups (P < 0.05).

CONCLUSION

High local control rates can be achieved with surgery followed by SRS. Further, adjuvant SRS following spine tumor surgery delivers less radiation to the wound than conventional radiation and thus potentially reduces wound complications. Unidimensional, bidimensional, and volumetric tumor assessments demonstrate similar results. Hence the use of the simpler RECIST criteria is suitable and appropriate for evaluating the response to treatment after spine radiosurgery.

Multimodality 3D Tumor Segmentation in HCC Patients Treated with TACE

RATIONALE AND OBJECTIVES

To validate the concordance of a semiautomated multimodality lesion segmentation technique between contrast-enhanced magnetic resonance imaging (CE-MRI), cone-beam computed tomography (CBCT), and multidetector CT (MDCT) in patients with hepatocellular carcinoma (HCC) treated with transarterial chemoembolization (TACE).

MATERIALS AND METHODS

This retrospective analysis included 45 patients with unresectable HCC who underwent baseline CE-MRI within 1 month before the treatment, intraprocedural CBCT during conventional TACE, and MDCT within 24 hours after TACE. Fourteen patients were excluded because of atypical lesion morphology, portal vein invasion, or small lesion size which precluded sufficient lesion visualization. Thirty-one patients with a total of 40 target lesions were included into the analysis. A tumor segmentation software, based on non-Euclidean geometry and theory of radial basis functions, was used to allow for the segmentation of target lesions in 3D on all three modalities. The algorithm created image-based masks located in a 3D region whose center and size were defined by the user, yielding the nomenclature "semiautomatic". On the basis of that, tumor volumes on all three modalities were calculated and compared using a linear regression model (R(2) values). Residual plots were used to analyze drift and variance of the values.

RESULTS

The mean value of tumor volumes was 18.72 ± 19.13 cm(3) (range, 0.41-59.16 cm(3)) on CE-MRI, 21.26 ± 21.99 cm(3) (range, 0.62-86.82 cm(3)) on CBCT, and 19.88 ± 20.88 cm(3) (range, 0.45-75.24 cm(3)) on MDCT. The average volumes of the tumor were not significantly different between CE-MRI and DP-CBCT, DP-CBCT and MDCT, MDCT and CE-MRI (P = .577, .770, and .794, respectively). A strong correlation between volumes on CE-MRI and CBCT, CBCT and MDCT, MDCT and CE-MRI was observed (R(2) = 0.974, 0.992 and 0.983, respectively). When plotting the residuals, no drift was observed for all methods showing deviations of no >10% of absolute volumes (in cm(3)).

CONCLUSIONS

A semiautomated 3D segmentation of HCC lesions treated with TACE provides high volumetric concordance across all tested imaging modalities.

Comparison of Existing Response Criteria in Patients with Hepatocellular Carcinoma Treated with Transarterial Chemoembolization Using a 3D Quantitative Approach

PURPOSE

To compare currently available non-three-dimensional methods (Response Evaluation Criteria in Solid Tumors [RECIST], European Association for Study of the Liver [EASL], modified RECIST [mRECIST[) with three-dimensional (3D) quantitative methods of the index tumor as early response markers in predicting patient survival after initial transcatheter arterial chemoembolization (TACE).

MATERIALS AND METHODS

This was a retrospective single-institution HIPAA-compliant and institutional review board-approved study. From November 2001 to November 2008, 491 consecutive patients underwent intraarterial therapy for liver cancer with either conventional TACE or TACE with drug-eluting beads. A diagnosis of hepatocellular carcinoma (HCC) was made in 290 of these patients. The response of the index tumor on pre- and post-TACE magnetic resonance images was assessed retrospectively in 78 treatment-naïve patients with HCC (63 male; mean age, 63 years ± 11 [standard deviation]). Each response assessment method (RECIST, mRECIST, EASL, and 3D methods of volumetric RECIST [vRECIST] and quantitative EASL [qEASL]) was used to classify patients as responders or nonresponders by following standard guidelines for the uni- and bidimensional measurements and by using the formula for a sphere for the 3D measurements. The Kaplan-Meier method with the log-rank test was performed for each method to evaluate its ability to help predict survival of responders and nonresponders. Uni- and multivariate Cox proportional hazard ratio models were used to identify covariates that had significant association with survival.

RESULTS

The uni- and bidimensional measurements of RECIST (hazard ratio, 0.6; 95% confidence interval [CI]: 0.3, 1.0; P = .09), mRECIST (hazard ratio, 0.6; 95% CI: 0.6, 1.0; P = .05), and EASL (hazard ratio, 1.1; 95% CI: 0.6, 2.2; P = .75) did not show a significant difference in survival between responders and nonresponders, whereas vRECIST (hazard ratio, 0.6; 95% CI: 0.3, 1.0; P = .04), qEASL (Vol) (hazard ratio, 0.5; 95% CI: 0.3, 0.9; P = .02), and qEASL (%) (hazard ratio, 0.3; 95% CI: 0.15, 0.60; P < .001) did show a significant difference between these groups.

CONCLUSION

The 3D-based imaging biomarkers qEASL and vRECIST were tumor response criteria that could be used to predict patient survival early after initial TACE and enabled clear identification of nonresponders.

Imaging for assessment of treatment response in hepatocellular carcinoma: Current update

Morphologic methods such as the Response Evaluation Criteria in Solid Tumors (RECIST) are considered as the gold standard for response assessment in the management of cancer. However, with the increasing clinical use of antineoplastic cytostatic agents and locoregional interventional therapies in hepatocellular carcinoma (HCC), conventional morphologic methods are confronting limitations in response assessment. Thus, there is an increasing interest in new imaging methods for response assessment, which can evaluate tumor biology such as vascular physiology, fibrosis, necrosis, and metabolism. In this review, we discuss various novel imaging methods for response assessment and compare them with the conventional ones in HCC.

Oesophageal cancer: assessment of tumour response to chemoradiotherapy with tridimensional CT

PURPOSE

To investigate whether changes in tumour volume were predictive of histopathological response to neoadjuvant therapy for oesophageal cancer.

MATERIALS AND METHODS

Thirty-five consecutive patients with locally advanced oesophageal cancer were treated with chemoradiotherapy and surgery in responders from July 2007 to July 2009. Tumour volume (TV) was calculated using innovative tumour volume estimation software which analysed computed tomography (CT) data. Tumour diameter and area were also evaluated. Variations in tumour measurements following neoadjuvant treatment were compared with the histopathological data.

RESULTS

Median baseline tumour diameter, area and volume were 3.51 cm (range 1.67-6.61), 7.51 cm(2) (range 1.79-21.0) and 33.80 cm(3) (range 3.36-101.6), respectively. Differences in TV between the pre- and post-treatment values were significantly correlated with the pathological stage (τ = 0.357, p = 0.004) and the tumour regression grade index (τ = 0.368, p = 0.005). According to the receiver operating characteristic analysis, TV measurements following treatment had moderate predictive values for the pathological T stage (area under the curve, AUC = 0.742, sensitivity = 55.56 %, specificity = 92.86 %, p = 0.005).Comparison of pathological and radiological volume showed a good precision (Pearson rho 0.77).

CONCLUSIONS

Changes in TV calculated on CT scans have a limited role in predicting pathological response to neoadjuvant treatment in oesophageal cancer patients. New imaging techniques based on metabolic imaging may provide better results.

Contemporary phase III clinical trial endpoints in advanced ovarian cancer: assessing the pros and cons of objective response rate, progression-free survival, and overall survival

Among gynecologic cancers, ovarian cancer provides the greatest challenge because 75% to 80% of patients present with stage III/IV disease. Over the last 40 years, a series of large trials conducted by the Gynecologic Oncology Group and other cooperative groups has produced striking improvements in patient outcome; but the majority still dies of their disease. Further research in both the laboratory and the clinic is essential to continued improvement in patient management. Clinical trials, however, have become a major challenge because of issues with trial endpoints. Historically, overall survival (OS) has been regarded as the "gold standard" of endpoints. Lack of effective treatment for patients who progressed on or recurred after front-line therapy allowed trials to avoid obfuscation of OS by post-progression therapy. More recently, studies have identified over 20 agents active against ovarian cancer. Reasonable evidence shows that effective post-progression therapy with multiple lines of active agents can render the survival endpoint uninterpretable. Two other endpoints avoid this problem. The objective response rate, assessed by the Response Evaluation Criteria in Solid Tumors (RECIST), is an accepted endpoint for accelerated approval in ovarian cancer. More importantly, progression-free survival (PFS), measured from study entry to progression of disease, avoids post-progression therapy completely. Without effective post-progression therapy (prior to 1990), data show that PFS is a surrogate for OS. Recent experience with 4 large trials of bevacizumab shows that PFS can be accurately assessed if progression is clearly defined and if timing of assessments is consistent in all study arms. Acceptance of PFS as the optimal endpoint for ovarian cancer trials by investigators and regulatory agencies is crucial to further advances in management because effective post-progression therapy has rendered differences in OS virtually impossible to assess reliably.

[The intra-observer variability of volumetric measurement of pulmonary nodules: comparison of two-dimensional and three-dimensional method]

背景与目的

未定性肺结节的随访需要精确测量结节体积确定其生长特性。结节体积的三维测量可通过软件实现并应用于临床，其在临床实践中的价值尚需进一步验证。本研究回顾性分析肺结节患者胸部CT平扫影像资料，比较三维体积测量与传统二维肺结节测量的观察者内的重复性。

方法

对2011年1月-2012年12月间在天津医科大学总医院行未定性肺结节CT随访研究的79例患者共86个结节的CT影像资料进行分析。由一名放射科医师对肺结节间隔1周行重复二维及三维体积测量。二维（two dimension, 2D）测量结节轴位最大横截面上的最大径（X）、相应垂直径（Y）及结节的头尾径（Z），分别根据球体及椭球体模型体积计算公式计算结节体积。三维（three dimension, 3D）测量通过计算机肺结节半自动体积测量软件进行，对结节自动体积分割效果不佳者行人工调整。应用Logistic回归分析评估结节的形态及位置对肺结节三维体积分割结果的影响。应用方差分析、相关分析评估3种体积测量方法的差异、Bland-Altman法评估3种方法的重复性。重复性定义为两次测量之间的相对差值（relative difference, RD）。

结果

86例结节两次三维软件体积测量中，软件分割效果满意结节占81.4%。Logistic回归分析提示边缘不规则结节及与血管相连结节软件分割不满意的比率明显增高，似然比（odds ratios, OR）分别为4.0、4.5。方差分析显示经二维测量与三维软件体积测量所得体积具有明显差异（F=6.5, P=0.012），同一方法两次重复测量结节体积间无统计学差异（F=1.813, P=0.182）。软件测量体积与椭球体模型体积相关性较球体模型高（相关系数分别为0.974、0.882）。3D软件体积测量重复性最佳，RD 95%一致性区间为-14%-11.6%，其次为2D椭球体模型体积(-37.7%-39.9%)，最后为2D球体模型（-44.63%-46.4%）。

结论

肺结节软件三维体积测量较二维测量具有更高的重复性。对软件体积分割不满意结节，包括不规则形态及与血管相连结节，我们建议测量结节的三维径线并应用椭球体模型计算体积。

Manual contouring based volumetric evaluation for colorectal cancer with liver limited metastases: a comparison with RECIST

BACKGROUND

To compare response evaluation criteria in solid tumours (RECIST) and volumetric evaluation (VE) for colorectal cancer with liver-limited metastasis.

PATIENTS AND METHODS

VE of liver metastases was performed by manual contouring before and after chemotherapy on 45 pairs of computed tomography (CT) images in 36 patients who suffered from metastatic colorectal cancer (mCRC) with liver metastasis only. Cohen kappa was used to compare the agreement between VE and RECIST. Pearson correlation was performed for their comparison after cubic root transformation of the aggregate tumor volumes. Logistic regression was done to identify clinical and radiographic factors to account for the difference which may be predictive in overall response (OR).

RESULTS

There were 16 partial response (PR), 23 stable disease (SD) and 6 progressive disease (PD) cases with VE, and 14 PR, 23 SD and 8 PD with RECIST. VE demonstrated good agreement with RECIST (κ=0.779). Discordant objective responses were noted in 6 pairs of comparisons (13.3%). Pearson correlation also showed excellent correlation between VE and RECIST (r2=0.966, p<0.001). Subgroup analysis showed that VE was in slightly better agreement with RECIST for enlarging lesions than for shrinking lesions (r2=0.935 and r2=0.780 respectively). No factor was found predictive of the difference in OR between VE and RECIST.

CONCLUSIONS

VE exhibited good agreement with RECIST. It might be more useful than RECIST in evaluation shrinking lesions in cases of numerous and conglomerate liver metastases.

Treatment of human pancreatic cancer using combined ultrasound, microbubbles, and gemcitabine: a clinical case study

PURPOSE

The purpose of this study was to investigate the ability and efficacy of inducing sonoporation in a clinical setting, using commercially available technology, to increase the patients' quality of life and extend the low Eastern Cooperative Oncology Group performance grade; as a result increasing the overall survival in patients with pancreatic adenocarcinoma.

METHODS

Patients were treated using a customized configuration of a commercial clinical ultrasound scanner over a time period of 31.5 min following standard chemotherapy treatment with gemcitabine. SonoVue(®) ultrasound contrast agent was injected intravascularly during the treatment with the aim to induce sonoporation.

RESULTS

Using the authors' custom acoustic settings, the authors' patients were able to undergo an increased number of treatment cycles; from an average of 9 cycles, to an average of 16 cycles when comparing to a historical control group of 80 patients. In two out of five patients treated, the maximum tumor diameter was temporally decreased to 80 ± 5% and permanently to 70 ± 5% of their original size, while the other patients showed reduced growth. The authors also explain and characterize the settings and acoustic output obtained from a commercial clinical scanner used for combined ultrasound microbubble and chemotherapy treatment.

CONCLUSIONS

It is possible to combine ultrasound, microbubbles, and chemotherapy in a clinical setting using commercially available clinical ultrasound scanners to increase the number of treatment cycles, prolonging the quality of life in patients with pancreatic adenocarcinoma compared to chemotherapy alone.

Functional imaging biomarkers for assessing response to treatment in liver and lung metastases

Management of patients with metastatic cancer and development of new treatments rely on imaging to provide non-invasive biomarkers of tumour response and progression. The widely used size-based criteria have increasingly become inadequate where early measures of response are required to avoid toxicity of ineffective treatments, as biological, physiologic, and molecular modifications in tumours occur before changes in gross tumour size. A multiparametric approach with the current range of imaging techniques allows functional aspects of tumours to be simultaneously interrogated. Appropriate use of these imaging techniques and their timing in relation to the treatment schedule, particularly in the context of clinical trials, is fundamental. There is a lack of consensus regarding which imaging parameters are most informative for a particular disease site and the best time to image so that, despite an increasing body of literature, open questions on these aspects remain. In addition, standardization of these new parameters is required. This review summarizes the published literature over the last decade on functional and molecular imaging techniques in assessing treatment response in liver and lung metastases.

Theranostics with Ga-68 somatostatin receptor PET/CT: monitoring response to peptide receptor radionuclide therapy

Peptide receptor radionuclide therapy involves selective targeting of neuroendocrine tumors through the somatostatin receptors, the aim being to increase radiation dose to the tumors and spare the normal tissue. The advantage of this internal radiation therapy is the ability to selectively target multiple metastases throughout the body. Early and accurate assessment of therapy response helps not only to identify the poor responders but also to personalize the treatment regimes with the aim of achieving maximum treatment benefit. This is the basis of theranostics.

Recurrent glioblastoma: volumetric assessment and stratification of patient survival with early posttreatment magnetic resonance imaging in patients treated with bevacizumab

BACKGROUND

Despite a high radiographic response rate in patients with recurrent glioblastoma following bevacizumab therapy, survival benefit has been relatively modest. We assess whether tumor volume measurements based on baseline and early posttreatment MRI can stratify patients in terms of progression-free survival (PFS) and overall survival (OS).

METHODS

Baseline (-4 +/- 4 days) and posttreatment (30 +/- 6 days) MRI exams of 91 patients with recurrent glioblastoma treated with bevacizumab were retrospectively evaluated for volume of enhancing tumor as well as volume of the T2/FLAIR hyperintensity. Overall survival (OS) and progression-free survival (PFS) were assessed using volume parameters in a Cox regression model adjusted for significant clinical parameters.

RESULTS

In univariable analysis, residual tumor volume, percentage change in tumor volume, steroid change from baseline to posttreatment scan, and number of recurrences were associated with both OS and PFS. With dichotomization by sample median of 52% change of enhancing volume can stratify OS (52 weeks vs. 31 weeks, P = .013) and PFS (21 weeks vs. 12 weeks, P = .009). Residual enhancing volume, dichotomized by sample median of 7.8 cm(3) , can also stratify for OS (64 weeks vs. 28 weeks, P < .001) and PFS (21 weeks vs. 12 weeks, P = .036).

CONCLUSIONS

Volumetric percentage change and absolute early posttreatment volume of enhancing tumor can stratify survival for patients with recurrent glioblastoma receiving bevacizumab therapy.

Automated registration, segmentation, and measurement of metastatic melanoma tumors in serial CT scans

OBJECTIVES

Our goal was to evaluate a new software capability that integrates registration, segmentation and tumor measurement across serial exams within a picture archiving communication system (PACS) to expedite tumor measurement.

MATERIALS AND METHODS

Patients treated under institutional review board-approved protocols for metastatic melanoma were retrospectively reviewed. Of the 19 included patients, five were male, the median age was 43.2, and all received treatment using an adoptive cell therapy. Seventy-one lung, liver, and subcutaneous tumors were manually measured using RECIST (Response Evaluation Criteria In Solid Tumors) criteria before therapy (baseline computed tomography [CT]) and within 3 months after therapy (follow-up CT). We performed semiautomated registration, segmentation, and RECIST measurements at both time points within PACS (Carestream Health, Rochester, NY). We compared manual and software-generated RECIST measurements using Bland-Altman plots.

RESULTS

The median manually measured RECIST diameter for all baseline tumors was 2.1 (1.0-6.2) cm. The refined registration function identified 70/71 (98.6%) tumors on the follow-up CT. On the baseline CT, all 21 liver, 27/32 (84%) lung, and 10/18 (55%) subcutaneous tumors completed segmentation. On the follow-up CT, 19/21 (90%) liver, 21/27 (78%) lung, and 8/10 (80%) subcutaneous tumors completed segmentation. The Bland-Altman plot demonstrated a 95% confidence interval of ±0.7 cm when comparing the software-generated and manual RECIST measurements.

CONCLUSIONS

The PACS software performed semiautomated baseline tumor measurements and fully automated follow-up tumor measurements in a majority of lung, liver, and subcutaneous tumors. In our patients, semiautomated metastatic tumor measurement did not obviate the need for physician oversight due to disease and treatment-related factors.

Established and novel imaging biomarkers for assessing response to therapy in hepatocellular carcinoma

The management of hepatocellular carcinoma (HCC) is evolving because of recently introduced novel therapeutic approaches. There is growing recognition that optimal outcome requires choosing treatment tailored to suit each individual patient, necessitating an early and accurate assessment of tumor response to therapy. The established and adapted image biomarkers based on size for tumor burden measurement continues to be applied to HCC as size measurement can easily be used in any clinical practice. However, in the setting of novel targeted therapies and liver directed treatments, simple tumor anatomical changes can be less informative and usually appear later than biological changes. Therefore the importance of image biomarkers such as tumor viability measurement, functional perfusion and diffusion imaging for response assessment is increasingly being recognized. Although promising, these imaging biomarkers have not gone through all the required steps of standardization and validation. In this review, we discuss various established, evolving and emerging imaging biomarkers and the criteria of response evaluation and their challenges in HCC.

Comparison of response evaluation criteria in solid tumors with volumetric measurements for estimation of tumor burden in pancreatic adenocarcinoma and hepatocellular carcinoma

BACKGROUND

Response evaluation criteria in solid tumors (RECIST) is the accepted method for determining tumor progression. However, RECIST may not estimate disease burden accurately because the axial plane often does not produce the actual longest diameter. Volumetric measurements may be an alternative to better determine tumor size. Our aim was to compare volumetric measurements with RECIST in pancreatic ductal adenocarcinomas (PDA) and hepatocellular carcinomas (HCC).

METHODS

RECIST and volumetric measurements were determined in 9 patients with metastatic PDA and 17 patients with HCC who subsequently underwent liver transplantation. Gross pathologic measurements after hepatectomy also were analyzed for volumes.

RESULTS

Three-dimensional diameter in volumetric analysis was 38% and 36% higher than RECIST diameter in PDA and HCC, respectively (P < .01). However, RECIST yielded 78% and 23% larger estimated tumor volumes than volumetric analysis in PDA and HCC, respectively (P < .01). Gross pathologic volume in HCC showed a linear correlation with both volumetric analysis (r = .95; P < .01) and RECIST (r = .96; P < .01) but RECIST significantly overestimated gross pathologic volume by an average of 28% (P < .01) whereas volumetric analysis was similar to gross pathologic volume (P = .56). In categorizing treatment response in PDA, RECIST and volumetric analysis were in moderate agreement (κ = .49).

CONCLUSIONS

RECIST significantly may overestimate tumor burden compared with volumetric measurements in both PDA and HCC. Volumetric analysis may be the preferred method to detect tumor progression.

MRI volume measurements compared with the RECIST 1.1 for evaluating the response to neoadjuvant chemotherapy for mass-type lesions

BACKGROUND

The purpose of this study was to compare the accuracy of volumetric (3D) measurements with that of unidimensional (1D) measurements by response evaluation criteria in solid tumors 1.1 (RECIST 1.1) in patients with breast cancer before and after neoadjuvant chemotherapy.

METHODS

The study included 48 patients with breast cancer who underwent neoadjuvant chemotherapy. Dynamic contrast-enhanced magnetic resonance imaging was performed before the first cycle of chemotherapy and after the completion of the planned chemotherapy. The longest diameter and volume of each target lesion were measured using a TeraRecon Aquarius workstation (San Mateo, CA). Response was assessed both by using the RECIST 1.1 and volumetric criteria. Histologic response was assessed using the Sataloff criteria. The agreements between the two measures and the histologic response were analyzed statistically.

RESULTS

In monitoring the response to neoadjuvant chemotherapy, the 1D and 3D measurements showed "good agreement" (κ = 0.610) for the treatment response categories and "moderate agreement" (κ = 0.565) for the responder/non-responder categories. Disagreement was observed in 9 out of 48 comparisons (18.75 %). The percent agreement of the 1D measurement of residual lesions (79.17 %) with the pathology was higher than that by volumetric measurement (70.83 %), but there was no statistically significant difference (p = 0.35). Both the 1D (rho = 0.67, p < 0.0001) and 3D measurements (rho = 0.52, p < 0.0001) showed a moderate degree of linear correlation with the pathologic diameter of residual lesions.

CONCLUSION

There was generally good agreement between the 1D and 3D measurements and moderate predictive value using either approach for predicting pathological response.