Measures of response: RECIST, WHO, and new alternatives

Stereotactic radiosurgery for single brainstem metastases: the cleveland clinic experience

PURPOSE

To assess the imaging and clinical outcomes of patients with single brainstem metastases treated with stereotactic radiosurgery (SRS).

MATERIALS AND METHODS

We retrospectively reviewed the data from patients with single brainstem metastases treated with SRS. Locoregional control and survival were calculated using the Kaplan-Meier method. Prognostic factors were assessed using a Cox proportional hazards model.

RESULTS

Between 1997 and 2007, 43 patients with single brainstem metastases were treated with SRS. The median age at treatment was 59 years, the median Karnofsky performance status was 80, and the median follow-up was 5.3 months. The median dose was 15 Gy (range, 9.6-24), and the median conformality and heterogeneity index was 1.7 and 1.9, respectively. The median survival was 5.8 months from the procedure date. Of the 33 patient with post-treatment imaging available, a complete radiographic response was achieved in 2 (4.7%), a partial response in 8 (18.6%), and stable disease in 23 (53.5%). The 1-year actuarial rate of local control, distant brain control, and overall survival was 85%, 38.3%, and 31.5%, respectively. Of the 43 patients, 8 (19%) died within 2 months of undergoing SRS, and 15 (36%) died within 3 months. On multivariate analysis, greater performance status (hazard ratio [HR], 0.95, p = .004), score index for radiosurgery (HR, 0.7; p = .004), graded prognostic assessment score (HR, 0.48; p = .003), and smaller tumor volume (HR, 1.23, p = .002) were associated with improved survival. No Grade 3 or 4 toxicities were observed.

CONCLUSION

The results of our study have shown that SRS is a safe and effective local therapy for patients with brainstem metastases.

State of the art management in spine oncology: a worldwide perspective on its evolution, current state, and future

STUDY DESIGN

A review of the past and current status of the evolving field of spine oncology.

OBJECTIVE

To provide a framework of reference for developments in the field, particularly the rapidly evolving field of molecular biology, as well as contemporary practice in the management of spine tumors.

METHODS

Literature review of the surgical treatment of spine tumors in the past and present, the emerging radiologic and biologic technologies, as well as the field of targeted therapy in cancer and the economic implications of technological advances.

RESULTS

A vast contemporary literature is currently available that provides a clear rational basis for treatment. Most treatment recommendations are currently based on retrospective data and small Phase II prospective studies. Treatment paradigms continue to evolve without their relative merits being evaluated by randomized controlled trials. The current lack of randomized trials in spine oncology reflect both the rarity of spine tumors and strongly held biases based on retrospective studies and institutional bias.

CONCLUSION

Spine oncology is a rapidly evolving field with contributions in surgery, radiation therapy, and targeted chemotherapy resulting in overall improvement in quality of life and survival in patients with spine tumors. However, the economic consequences of these improvements are substantial and need to be kept in proper perspective.

Early MRI response monitoring of patients with advanced hepatocellular carcinoma under treatment with the multikinase inhibitor sorafenib

Background

New therapeutic principles in clinical oncology require the adjustment of response criteria to govern therapy decisions. For advanced hepatocellular carcinoma (HCC) a new era has recently begun by the approval of the multikinase inhibitor sorafenib. As a unique feature, HCC usually develops in a diseased liver and current imaging technologies employing classical response criteria have not been prospectively evaluated for this new treatment.

Methods

MRI signal patterns were assessed in 21 advanced HCC patients receiving sorafenib. MRI was performed at baseline and in short-term intervals thereafter. Signal changes under therapy on T1WI, T2WI and post-gadolinium images including necrosis volume and its ratio to the entire tumor volume were compared to baseline imaging. To assess the association between the categorical variables, Fisher's exact tests were applied for a statistical analysis. Survey time ranged from 2–65 weeks, and a total of 39 target lesions were evaluated.

Results

Signal abnormalities during sorafenib therapy were disclosed by T1WI and T2WI in 15/21 patients. The predominant tumor signal change was hyperintensity on both T1WI and T2WI. Interestingly, most patients developed MRI signal changes within 4 weeks of therapy; in contrast, two non-responders did not show any signal alteration at follow-up. Under therapy, 16/21 patients presented with new or progressive necrosis, whereas 7 patients achieved temporarily >75% tumor necrosis under sorafenib. Significantly associated MRI variables were increase in T1WI signal and tumor necrosis (p = 0.017) as well as increase of tumor necrosis with an elevated ratio of necrotic to vital tumor areas (p = 0.002). Remarkably, some (3/13) of the patients developing necrotic tumor areas showed a relevant (>20%) increase in tumor volume, which should be considered in the assessment of imaging studies.

Conclusion

As sorafenib induces early intralesional necrosis with profound changes in T1WI/T2WI MRI signal intensities and measurable necrotic tumor areas in most HCC patients, early MRI-based evaluation could pave the way for its rationale and cost-effective application.

Semi-automated quantification of hepatic lesions in a phantom

PURPOSE

Accurate measurement is crucial for the assessment of tumor dimensions to allow accurate evaluation of tumor response. Thus, the purpose of our study was to assess the accuracy of semi-automated RECIST and volumetric measurements of liver lesions in a liver phantom with different CT acquisition parameters.

MATERIALS AND METHODS

A phantom of the upper abdomen with 14 hepatic lesions of different sizes (diameter: 12.0-40.0 mm), densities (45/180 HU at 120 kV), or alignment (vertical/transverse) was scanned with a 16-slice multidetector row computed tomography using varying tube currents (40/60/80/100/120/165mAs eff), reconstruction kernels (Siemens B20/30/40/50/70s), or slice thicknesses (1/2/3/4/5 mm). Longest axial diameter and volume of the 14 lesions were quantified using a semi-automated software tool (SyngoOncology, Siemens Medical Solutions, Forchheim, Germany) and compared with the known real longest axial diameter and volume values of the lesions. Absolute percentage errors (APE) were calculated. Degree of agreement in longest axial diameter and volume between software and real measurements was represented graphically in Bland-Altman plots and by corresponding concordance correlation coefficient.

RESULTS

At standard soft tissue reconstruction kernel (Siemens B30s) and slice thickness (3 mm) mean absolute percentage error APE (concordance correlation coefficients) ranged between 6.93 and 14.27 (0.96 and 0.99) for longest axial diameter and between 4.98 and 10.85 (0.99 and 1.00) for volume. At varying reconstruction kernels, APE values (concordance correlation coefficients) ranged between 7.92 and 8.31 (0.98 and 0.99) for longest axial diameter and between 4.95 and 6.93 (1.00) for volume. Applying different slice sections APE values (concordance correlation coefficients) differed from 6.54 to 11.82 (0.97 and 0.99) for longest axial diameter and from 6.93 to 9.17 (1.00) for volume.

CONCLUSIONS

Software quantification of longest axial diameter and volume of hepatic lesions in a phantom demonstrated a high correlation and accuracy under varying multidetector row computed tomography parameter.

High-grade soft-tissue sarcomas: tumor response assessment--pilot study to assess the correlation between radiologic and pathologic response by using RECIST and Choi criteria

PURPOSE

To compare radiologic response as defined according to both Response Evaluation Criteria in Solid Tumors (RECIST) and the new Choi criteria recently proposed for gastrointestinal stromal tumors with pathologic response in high-grade soft-tissue sarcomas (STSs) treated with preoperative chemotherapy and radiation therapy.

MATERIALS AND METHODS

The institutional ethical committee approved the trial in which patients were enrolled. Signed informed consent was obtained. Thirty-seven patients (21 men, 16 women; mean age, 44.2 years) enrolled in a collaborative randomized trial on preoperative chemotherapy and radiation therapy in localized high-risk STS at a single institution were selected for this retrospective analysis. Tumor response to preoperative treatment was assessed by using both RECIST and Choi criteria at computed tomography (CT) and was adapted to be used at magnetic resonance (MR) imaging. Pathologic response was assessed as either good or very good. Sensitivity, specificity, and predictive value of RECIST and Choi criteria were calculated with pathologic response as the reference standard and were reported with 95% confidence intervals.

RESULTS

For 28 patients without synovial sarcomas, sensitivity of RECIST versus adapted Choi criteria was 32.0% versus 88.0% for good response and 41.2% versus 82.4% for very good response, respectively; specificity for pathologic response was 100% versus 100% for not a good response and 90.9% versus 27.3% for not a very good response, respectively. In synovial sarcoma, the nontreatment-related neoplastic cystic component of the tumor was a major obstacle for both RECIST and Choi criteria.

CONCLUSION

In STS treated with chemotherapy and radiation therapy, tumor size may be insufficient to render actual tumor response. Tumor attenuation at CT or tumor contrast material enhancement at MR imaging may complement tumor size, thus making Choi criteria more predictive of pathologic response.

Noncalcified lung nodules: volumetric assessment with thoracic CT

Lung nodule volumetry is used for nodule diagnosis, as well as for monitoring tumor response to therapy. Volume measurement precision and accuracy depend on a number of factors, including image-acquisition and reconstruction parameters, nodule characteristics, and the performance of algorithms for nodule segmentation and volume estimation. The purpose of this article is to provide a review of published studies relevant to the computed tomographic (CT) volumetric analysis of lung nodules. A number of underexamined areas of research regarding volumetric accuracy are identified, including the measurement of nonsolid nodules, the effects of pitch and section overlap, and the effect of respiratory motion. The need for public databases of phantom scans, as well as of clinical data, is discussed. The review points to the need for continued research to examine volumetric accuracy as a function of a multitude of interrelated variables involved in the assessment of lung nodules. Understanding and quantifying the sources of volumetric measurement error in the assessment of lung nodules with CT would be a first step toward the development of methods to minimize that error through system improvements and to correctly account for any remaining error.

The minimum number of target lesions that need to be measured to be representative of the total number of target lesions (according to RECIST)

Response evaluation criteria in solid tumours (RECIST) were introduced as a means to classify tumour response with no definition of the minimum number of lesions. This study was conducted in order to evaluate discrepancies between full assessments based on either all target lesions or fewer lesions. RECIST evaluation was performed on separate occasions based on between one and seven of the target lesions, with simultaneous assessment of non-target lesions. 99 patients were included. 38 patients demonstrated progressive disease, in 61% of whom it was a result of the appearance of new lesions or unequivocal progress in non-target lesions. 32 patients showed stable disease, with 8 having results that differed when 1-3 target lesions were measured. 22 cases were considered as having partial regression, with only 1 case differing when performing 1-3 target lesion assessments. Seven cases demonstrated complete response. The number of discordant cases increased gradually from measuring three lesions to one target lesion. The average number of available target lesions among those with discrepancies was 7.1, which was significantly higher than those demonstrating concordance (4.1 lesions; p<0.05). In conclusion, measuring fewer than four target lesions might cause discrepancies when more than five target lesions are present.

Preliminary results of M-VAC chemotherapy combined with mild hyperthermia, a new therapeutic strategy for advanced or metastatic transitional cell carcinoma of the urothelium

OBJECTIVE

We evaluated the efficacy and safety of M-VAC chemotherapy combined with mild hyperthermia, a new therapeutic strategy for advanced metastatic transitional cell carcinoma of the urothelium.

SUBJECTS AND METHODS

The subjects were 12 patients diagnosed with advanced metastatic transitional cell carcinoma of the urothelium. For mild hyperthermia, the patients' oral temperature was elevated to about 38 degrees C by heating for 20 min and retaining the heat for 20 min with a far-infrared heater. The antitumor effect was evaluated according to the RECIST, while adverse drug reactions were assessed based on the NCI-CTC.

RESULTS

The antitumor effect was rated as partial remission (PR) in 10 of the 12 patients and stable disease in 2 patients, with an efficacy rate of 83% (10/12). All 10 patients who had achieved PR received three courses of treatment. Of the 12 patients, 5 died during the observation period, with survival for 9-23 months (mean: 15.6 months). Adverse drug reactions included myelosuppression in all patients (Grade 3 in 4 patients, Grade 4 in 8), and gastrointestinal toxicity, such as nausea or vomiting, which was mild (Grade 0 in 2 patients, Grade 1 in 8, Grade 2 in 1, Grade 3 in 1).

CONCLUSIONS

The results of the present study suggest that M-VAC chemotherapy combined with mild hyperthermia, which potentiates the anticancer effect and reduces adverse drug reactions such as gastrointestinal symptoms, is a useful and safe method for the treatment of advanced transitional cell carcinoma of the urothelium.

Fludarabine modulates immune response and extends in vivo survival of adoptively transferred CD8 T cells in patients with metastatic melanoma

Background

Adoptive T cell therapy involving the use of ex vivo generated antigen-specific cytotoxic T lymphocytes provides a promising approach to immunotherapy. It has become increasingly apparent that anti-tumor efficacy using adoptively transferred T cells is linked to their duration of in vivo persistence and can only be achieved when combined with some form of pre-infusion patient conditioning regimen. An optimal conditioning regimen that provides a positive benefit without serious toxicities has yet to be defined. We have established a unique clinical model that allows for evaluation of a given conditioning regimen on adoptively transferred T cells in humans. In this first-in-human study (FHCRC #1796), we evaluate the use of fludarabine, an FDA-approved reagent with predictable lymphodepleting kinetics and duration of action, as a conditioning regimen that promotes homeostatic upregulation of cytokines and growth signals contributing to in vivo T cell persistence.

Methods/Findings

We conducted a phase I study in patients with refractory metastatic melanoma. Patients received two infusions of a single tumor-reactive antigen-specific CTL clone expanded to 10¹⁰/m²; the first infusion was given without fludarabine conditioning, and the second CTL infusion was given after a course of fludarabine (25 mg/m²/day×5 days). This design permits intra-patient comparison of in vivo T cell persistence pre- and post-fludarabine. Nineteen CTL infusions were administered to ten patients. No serious toxicities were observed. Three of nine evaluable patients experienced minor response or stable disease for periods of 5.8–11.0 months with two additional patients demonstrating delayed disease stabilization. The median overall survival in this heavily pre-treated population was 9.7 months. Fludarabine led to a 2.9 fold improvement in the in vivo persistence of transferred CTL clones from a median of 4.5 days (range 0–38+) to 13.0 days (range 2–63+) (p<0.05). Fludarabine lymphodepletion increased plasma levels of the homeostatic cytokines IL-7 and IL-15. Surprisingly, fludarabine also increased the relative percentage of CD4+ T cells expressing the regulatory protein Foxp3.

Conclusions/Significance

Lymphodepletion with fludarabine enhances transferred T cell persistence but suggest that additional improvements to optimize T cell survival and address regulatory T cells are critical in providing anti-tumor efficacy.

Trial Registration

ClinicalTrials.gov NCT00317759

Treatment response classification of liver metastatic disease evaluated on imaging. Are RECIST unidimensional measurements accurate?

The purpose of this study was to evaluate the accuracy of unidimensional measurements (response evaluation criteria in solid tumors, RECIST) compared with volumetric measurements in patients with liver metastases undergoing chemotherapy. Forty-four patients with newly diagnosed liver lesions underwent three MRI examinations at treatment initiation, during chemotherapy, and immediately post-treatment. Measurements based on RECIST guidelines and volume calculations were performed on the "target" lesions (TLs). The two methods were in agreement in 64/77 of patients and 253/301 of individual lesions classification in response categories ("good" agreement, Cohen kappa = 0.735 and 0.741, respectively). In 16.88% of the comparisons the two methods stratified patients to a different response category; 27.6% of TLs did not follow the response category of the patient in whom lesions were located. The actual volume of TLs differs from the calculated volume of a sphere with the same diameter. Our study supports the use of volumetric techniques that may overcome certain disadvantages of unidimensional measurements.

Response to chemotherapy predicts survival following resection of hepatic colo-rectal metastases in patients treated with neoadjuvant therapy

BACKGROUND

Prognosis of patients following resection of CRC metastases to the liver has traditionally been predicted by clinical risk factors. In the era of neoadjuvant chemotherapy, determination of new prognostic indicators of outcome are necessary.

METHODS

This retrospective study includes patients with CRC liver metastases, who received oxaliplatin or irinotecan based neoadjuvant chemotherapy and underwent R0 resection. Patients were followed by CT and PET-CT, before, during and after chemotherapy and surgery. The predictive value of the Memorial Sloan-Kettering Cancer Center Clinical Score (MSKCC-CS) and degree of response to chemotherapy (measured by CT and PET-CT), were analyzed by univariate and multivariate COX regression.

RESULTS

Included are 54 patients. Overall 1-, 2-, 3-year survival rates 88%, 70%, and 39%. Response to chemotherapy on CT was a significant predictor of survival on univariate (P = 0.03) and multivariate analysis (P = 0.03), whereas MSKCC-CS and response to chemotherapy on PET-CT were not. Multivariate analysis demonstrated response to chemotherapy as a predictor of time to recurrence on CT (P = 0.02) and PET-CT (P = 0.03), while the MSKCC-CS (P = 0.64) was not.

CONCLUSIONS

In this cohort of patients treated by neoadjuvant chemotherapy, the outcome was not predicted by the traditional clinical scoring system, but rather by response to chemotherapy as evaluated by CT and PET-CT.

A phase I study of gefitinib, capecitabine, and celecoxib in patients with advanced solid tumors

This phase I study was designed to determine the maximum tolerated dose (MTD) and toxicity profile of the combination of gefitinib, capecitabine, and celecoxib in patients with advanced solid tumors. Patients were treated with escalating doses of gefitinib once daily, capecitabine twice daily (14 of 28 days), and celecoxib twice daily. Plasma samples for biomarkers were obtained at baseline and weekly for the first 2 cycles. Pharmacokinetic variables were correlated with toxicity and presence of biological effect. Tumor biopsies from 5 patients were analyzed for changes in tumor metabolic activity by nuclear magnetic resonance spectroscopy. [18F]fluorodeoxyglucose positron emission tomography was done as a correlate in 6 patients at the MTD. Thirty-nine patients received 168 cycles of therapy. The dose-limiting toxicities observed included nausea, dehydration and nausea, diarrhea, and stomatitis. The MTD was 250 mg/d gefitinib (days 1-14) and 2,000 mg/m2/d capecitabine divided twice daily (days 8-21) every 28 days. Celecoxib was eliminated due to concerns of increased risk for cardiovascular toxicity, although no patients in this study had cardiac events. One patient with cholangiocarcinoma had a confirmed partial response. Fourteen of 39 (36%) patients maintained prolonged stable disease for a median of 4 months (range, 3-24 months). [18F]fluorodeoxyglucose positron emission tomography scan and metabolomic analyses revealed differences in metabolic response to gefitinib versus capecitabine. The combination of gefitinib and capecitabine is well tolerated and appears to have activity against certain advanced solid tumors, providing a rationale for further evaluation in advanced solid malignancies.

Molecular imaging of therapeutic response to epidermal growth factor receptor blockade in colorectal cancer

PURPOSE

To evaluate noninvasive molecular imaging methods as correlative biomarkers of therapeutic efficacy of cetuximab in human colorectal cancer cell line xenografts grown in athymic nude mice. The correlation between molecular imaging and immunohistochemical analysis to quantify epidermal growth factor (EGF) binding, apoptosis, and proliferation was evaluated in treated and untreated tumor-bearing cohorts.

EXPERIMENTAL DESIGN

Optical imaging probes targeting EGF receptor (EGFR) expression (NIR800-EGF) and apoptosis (NIR700-Annexin V) were synthesized and evaluated in vitro and in vivo. Proliferation was assessed by 3'-[18F]fluoro-3'-deoxythymidine ([18F]FLT) positron emission tomography. Assessment of inhibition of EGFR signaling by cetuximab was accomplished by concomitant imaging of NIR800-EGF, NIR700-Annexin V, and [18F]FLT in cetuximab-sensitive (DiFi) and insensitive (HCT-116) human colorectal cancer cell line xenografts. Imaging results were validated by measurement of tumor size and immunohistochemical analysis of total and phosphorylated EGFR, caspase-3, and Ki-67 immediately following in vivo imaging.

RESULTS

NIR800-EGF accumulation in tumors reflected relative EGFR expression and EGFR occupancy by cetuximab. NIR700-Annexin V accumulation correlated with cetuximab-induced apoptosis as assessed by immunohistochemical staining of caspase-3. No significant difference in tumor proliferation was noted between treated and untreated animals by [18F]FLT positron emission tomography or Ki-67 immunohistochemistry.

CONCLUSIONS

Molecular imaging can accurately assess EGF binding, proliferation, and apoptosis in human colorectal cancer xenografts. These imaging approaches may prove useful for serial, noninvasive monitoring of the biological effects of EGFR inhibition in preclinical studies. It is anticipated that these assays can be adapted for clinical use.

PET Imaging of Angiogenesis

Angiogenesis is a highly-controlled process that is dependent on the intricate balance of both promoting and inhibiting factors, involved in various physiological and pathological processes. A comprehensive understanding of the molecular mechanisms that regulate angiogenesis has resulted in the design of new and more effective therapeutic strategies. Due to insufficient sensitivity to detect therapeutic effects by using standard clinical endpoints or by looking for physiological improvement, a multitude of imaging techniques have been developed to assess tissue vasculature on the structural, functional and molecular level. Imaging is expected to provide a novel approach to noninvasively monitor angiogenesis, to optimize the dose of new antiangiogenic agents and to assess the efficacy of therapies directed at modulation of the angiogenic process. All these methods have been successfully used preclinically and will hopefully aid in antiangiogenic drug development in animal studies. In this review article, the application of PET in angiogenesis imaging at both functional and molecular level will be discussed. For PET imaging of angiogenesis related molecular markers, we emphasize integrin alpha(v)beta(3), VEGF/VEGFR, and MMPs.

Validation of novel imaging methodologies for use as cancer clinical trial end-points

The success or failure of a clinical trial, of any phase, depends critically on the choice of an appropriate primary end-point. In the setting of phases II and III cancer clinical trials, imaging end-points have historically, and continue presently to play a major role in determining therapeutic efficacy. The primary goal of this paper is to discuss the validation of imaging-based markers as end-points for phase II clinical trials of cancer therapy. Specifically, we outline the issues that must be considered, and the criteria that would need to be satisfied, for an imaging end-point to supplement or potentially replace RECIST- defined tumour status as a phase II clinical trial end-point. The key criteria proposed to judge the utility of a new end-point primarily relate to its ability to accurately and reproducibly predict the eventual phase III end-point for treatment effect, which is usually assessed by a difference between two arms on progression free or overall survival, both at the patient and more importantly at the trial level. As will be demonstrated, the level of evidence required to formally and fully validate a new imaging marker as an appropriate end-point for phase II trials is substantial. In many cases, this level of evidence will only become available by conducting a series of coordinated prospectively designed multicentre clinical trials culminating in a formal meta-analysis. We also include a discussion of situations where flexibility may be required, relative to the ideal rigorous evaluation, to accommodate inevitable real-world feasibility constraints.

PET for Therapeutic Response Monitoring in Oncology

After diagnosis and staging of cancer, the most important process in modern oncology is assessment of therapeutic response. Timely identification of patients with poor response may allow introduction of alternative therapies, sparing patients the toxicity of ineffective treatments, reducing health care cost, and potentially delivering better outcomes. Metabolic imaging using PET is increasingly recognized as providing earlier and more robust assessment than conventional imaging. There are now ample clinical data indicating that PET metabolic response should be strongly considered for inclusion in evaluation of clinical response in individual high-risk malignancies to both direct the care of individual patients and to guide application of new therapies in particular cancer populations.

Phase I trial of interleukin-12 plasmid electroporation in patients with metastatic melanoma

PURPOSE

Gene-based immunotherapy for cancer is limited by the lack of safe, efficient, reproducible, and titratable delivery methods. Direct injection of DNA into tissue, although safer than viral vectors, suffers from low gene transfer efficiency. In vivo electroporation, in preclinical models, significantly enhances gene transfer efficiency while retaining the safety advantages of plasmid DNA.

PATIENTS AND METHODS

A phase I dose escalation trial of plasmid interleukin (IL)-12 electroporation was carried out in patients with metastatic melanoma. Patients received electroporation on days 1, 5, and 8 during a single 39-day cycle, into metastatic melanoma lesions with six 100-mus pulses at a 1,300-V/cm electric field through a penetrating six-electrode array immediately after DNA injection. Pre- and post-treatment biopsies were obtained at defined time points for detailed histologic evaluation and determination of IL-12 protein levels.

RESULTS

Twenty-four patients were treated at seven dose levels, with minimal systemic toxicity. Transient pain after electroporation was the major adverse effect. Post-treatment biopsies showed plasmid dose proportional increases in IL-12 protein levels as well as marked tumor necrosis and lymphocytic infiltrate. Two (10%) of 19 patients with nonelectroporated distant lesions and no other systemic therapy showed complete regression of all metastases, whereas eight additional patients (42%) showed disease stabilization or partial response.

CONCLUSION

This report describes the first human trial, to our knowledge, of gene transfer utilizing in vivo DNA electroporation. The results indicated this modality to be safe, effective, reproducible, and titratable.

[Not Available]

S. Taïeb, L. Ceugnart, F. Bonodeau, L. Vanseymortier, A. Adenis The management and the prognosis of gastrointestinal stromal tumors (GIST) have evolved rapidly with new targeted treatments. The aim of this paper is to assess the role of imaging not only for diagnosis but to quantify treatment response. RECIST criteria, which are the standard in assessment of post chemotherapy response in adult's solid tumors, can not be used in targeted therapy: the changes in lesion structures even if case of increasing volume are more specific to assess tumor response.

Discrete-space versus continuous-space lesion boundary and area definitions

Measurement of the size of anatomic regions of interest in medical images is used to diagnose disease, track growth, and evaluate response to therapy. The discrete nature of medical images allows for both continuous and discrete definitions of region boundary. These definitions may, in turn, support several methods of area calculation that give substantially different quantitative values. This study investigated several boundary definitions (e.g., continuous polygon, internal discrete, and external discrete) and area calculation methods (pixel counting and Green's theorem). These methods were applied to three separate databases: A synthetic image database, the Lung Image Database Consortium database of lung nodules and a database of adrenal gland outlines. Average percent differences in area on the order of 20% were found among the different methods applied to the clinical databases. These results support the idea that inconsistent application of region boundary definition and area calculation may substantially impact measurement accuracy.

Virus-specific T cells engineered to coexpress tumor-specific receptors: persistence and antitumor activity in individuals with neuroblastoma

Cytotoxic T lymphocytes (CTLs) directed to nonviral tumor-associated antigens do not survive long term and have limited antitumor activity in vivo, in part because such tumor cells typically lack the appropriate costimulatory molecules. We therefore engineered Epstein-Barr virus (EBV)-specific CTLs to express a chimeric antigen receptor directed to the diasialoganglioside GD2, a nonviral tumor-associated antigen expressed by human neuroblastoma cells. We reasoned that these genetically engineered lymphocytes would receive optimal costimulation after engagement of their native receptors, enhancing survival and antitumor activity mediated through their chimeric receptors. Here we show in individuals with neuroblastoma that EBV-specific CTLs expressing a chimeric GD2-specific receptor indeed survive longer than T cells activated by the CD3-specific antibody OKT3 and expressing the same chimeric receptor but lacking virus specificity. Infusion of these genetically modified cells seemed safe and was associated with tumor regression or necrosis in half of the subjects tested. Hence, virus-specific CTLs can be modified to function as tumor-directed effector cells.

Whole body diffusion weighted imaging: a new era of oncological radiology

Cancer has become the leading cause of mortality in the urban area of China. Whole body diffusion weighted imaging (WB-DWI), also known as virtual positron emission tomography, has gradually become accepted as an image tool in tumor localization, characterization, staging and monitoring response to therapy or tumor recurrence. Our article aimed to summarize the limited initial clinical use of WB-DWI in the referred area, and to analyze the most potential advantage of WB-DWI in therapeutic monitoring and tumor staging. WB-DWI as a highly sensitive, completely non-invasive, well-tolerated and low price technique has a promising furture in tumor assessment. Profound clinical study is necessary for its further application improvement.

The Translational Research Working Group developmental pathway for image-based assessment modalities

The Image-based assessment modality (IM) pathway refers to one of six Translational Research Working Group (TRWG) pathways that, together, describe the core domains of early translational cancer research. This pathway focuses on approaches that are based on the interaction of energy and living organisms to analyze tissue noninvasively so as to reveal properties relevant to the detection, diagnosis, or prognosis of cancer and precancer; or the response of the cancer to therapy. Examples include, but are not limited to, magnetic resonance imaging and positron emission tomography, as well as contemporary contrast agents designed to probe specific molecular constituents of tumors. The IM pathway is presented as a general outline of the steps required for the effective development, optimization, testing, and validation of image-based modalities. The distinctive features of the IM pathway and issues encountered that represent obstacles to effective and efficient progress through the pathway are discussed. The IM pathway also forms a framework to identify opportunities to address current barriers and is expected to adapt and evolve as the field advances.

Usefulness of the serum carcinoembryonic antigen kinetic for chemotherapy monitoring in patients with unresectable metastasis of colorectal cancer

PURPOSE

The aim of the study was to evaluate the relationship between serum carcinoembryonic antigen (CEA) kinetic and response to chemotherapy in patients with unresectable metastasis of colorectal cancer.

PATIENTS AND METHODS

The kinetic was calculated using the slope of an exponential-regressive curve connecting the semi-logarithmic values of CEA. Receiver operating characteristic (ROC) curves were drawn to select the CEA slope thresholds to define patients with progressive or responsive disease with the highest sensitivity, specificity, and diagnosis accuracy odds ratio (DOR). The correlation between the CEA slopes and progression-free survival (PFS) was evaluated by the Cox model and Kaplan-Meier methods.

RESULTS

A total of 122 patients were included. Progression defined by CEA slope greater than +0.05 resulted in sensitivity of 85.7%, specificity of 85.1%, and DOR of 34. The area under the ROC (AUROC) curve was 0.885 (95% CI, 0.815 to 0.936; P = .0001). Response defined by CEA slope less than -0.2 resulted in sensitivity of 74.7%, specificity of 82.5%, and DOR of 16. The AUROC curve was 0.847 (95% CI, 0.770 to 0.906; P = .0001). The difference between AUROC curves calculated with six or four CEA values was not significant. PFS was correlated with CEA slopes (hazard ratio, 4.6; 95% CI, 2.48 to 8.57). The median PFS was 10 months for patients with CEA slope values less than -0.2 months versus 6 months for patients with CEA slope values greater than -0.2 (P < .0001).

CONCLUSION

These results suggest that the CEA kinetic is an accurate, simple, and noninvasive method to identify the disease progression in patients with unresectable metastasis of colorectal cancer.

Blinded independent central review of progression-free survival in phase III clinical trials: important design element or unnecessary expense?

Progression-free survival is an important end point in advanced disease settings. Blinded independent central review (BICR) of progression in randomized clinical trials has been advocated to control bias that might result from errors in progression assessments. However, although BICR lessens some potential biases, it does not remove all biases from evaluations of treatment effectiveness. In fact, as typically conducted, BICRs may introduce bias because of informative censoring, which results from having to censor unconfirmed locally determined progressions. In this article, we discuss the rationale for BICR and different ways of implementing independent review. We discuss the limitations of these approaches and review published trials that report implementing BICR. We demonstrate the existence of informative censoring using data from a randomized phase II trial. We conclude that double-blinded trials with consistent application of measurement criteria are the best means of ensuring unbiased trial results. When such designs are not practical, BICR is not recommended as a general strategy for reducing bias. However, BICR may be useful as an auditing tool to assess the reliability of marginally positive results.

Validation of radiographic response evaluation criteria of preoperative chemotherapy for bone and soft tissue sarcomas: Japanese Orthopaedic Association Committee on Musculoskeletal Tumors Cooperative Study

BACKGROUND

The radiographic evaluation of the response to preoperative chemotherapy for bone and soft tissue sarcomas is based mostly on the change in primary tumor size before and after chemotherapy, as is done for many solid cancers. Its prognostic correlation, however, has hardly been validated.

METHODS

We conducted a retrospective validation study of the Japanese Orthopaedic Association (JOA) radiographic response evaluation criteria of preoperative chemotherapy for bone and soft tissue sarcomas as a JOA Committee on Musculoskeletal Tumors cooperative study. A total of 125 consecutive patients with high-grade bone (n = 77) and soft tissue (n = 48) sarcomas treated with neoadjuvant chemotherapy and definitive surgery in 25 tertiary referral hospitals were selected for the study. We investigated the correlation between the tumor size-based radiographic response evaluation criteria of preoperative chemotherapy for bone and soft tissue sarcomas provided by the JOA Committee on Musculoskeletal Tumors (hereafter called the JOA criteria) and the patients' overall survival using the Kaplan-Meier method and the log-rank test.

RESULTS

The JOA criteria correlated relatively well with survival for malignant bone tumors (mostly comprising osteosarcoma and Ewing's sarcoma) but not for soft tissue sarcomas, suggesting that the tumor size-based radiographic evaluation criteria for the response to preoperative chemotherapy in patients with soft tissue sarcomas is invalid.

CONCLUSIONS

The JOA criteria, based on the change in primary tumor size, is valid for malignant bone tumors but invalid for soft tissue sarcomas. Other new evaluation modalities of the response to preoperative chemotherapy using innovative functional imaging techniques are needed for soft tissue sarcomas.

Qualitative radiology assessment of tumor response: does it measure up?

Our purpose was to assess whether a simpler qualitative evaluation of tumor response by computed tomography is as reproducible and predictive of clinical outcome as the Response Evaluation Criteria in Solid Tumors (RECIST) and World Health Organization (WHO) methods. This study was a two-reader retrospective evaluation in which qualitative assessment resulted in agreement in 21 of 23 patients with metastatic colorectal carcinoma (91.3%, kappa=0.78; 95% CI, 0.51-1.00). Hepatic metastases were classified as increased, decreased, or unchanged, compared with agreement in 20 of 23 patients (87.0%) for RECIST (kappa=0.62; 95% CI, 0.23-1.00) and WHO (kappa=0.67; 95% CI, 0.34-1.00) methods. Patients were placed into partial response, stable disease, and disease progression categories. Time to progression of disease was better predicted qualitatively than by RECIST or WHO. Our pilot data suggest that our qualitative scoring system is more reproducible and predictive of patient clinical outcome than the RECIST and WHO methods.

Using extracellular biomarkers for monitoring efficacy of therapeutics in cancer patients: an update

Rapidly detectable and easily accessible markers of tumor cell death are needed for evaluating early therapeutic efficacy for immunotherapy and chemotherapy so that patients and their physicians can decide whether to remain with a given therapeutic strategy. Currently, image-based tests such as computed tomography scans and magnetic resonance imaging are used to visualize the response of a patient's tumor, but often these evaluations are not conducted for weeks to months after treatment begins. While serum levels of secreted proteins such as carcinoembryonic antigen and prostate specific antigen are commonly monitored to gauge tumor status during therapy and between image evaluations, the levels of these proteins do not always correlate well with the actual tumor response. In laboratory studies, it has been shown that tumor cells undergoing apoptosis can release cellular components into cell culture media such as cytochrome c, nucleosomes, cleaved cytokeratin-18 and E-cadherin. Studies of patient sera have found that these and other macromolecules can be found in circulation during cancer therapy, providing a potential source of material for monitoring treatment efficacy. In the future, analysis of biofluids from severe combined immunodeficiency mice bearing patient tumor specimens treated with a targeted therapy such as Apo2L/tumor necrosis factor-related apoptosis-inducing ligand will be useful in the preclinical identification of therapy response markers. In this review, the current status of the identification of serum markers of tumor cell apoptosis is provided, as well as a discussion of critical research questions that must be addressed and the considerations necessary when identifying a marker that reflects true clinical outcome.

Pulmonary cavitary sarcoidosis: clinico-radiologic characteristics and natural history of a rare form of sarcoidosis

Pulmonary cavitary lesions in the absence of concomitant comorbidities are an uncommon and often confusing manifestation of sarcoidosis. We retrospectively reviewed the clinical and high-resolution computed tomography (HRCT) characteristics and the natural history of a series of 23 patients with pulmonary cavitary lesions found on HRCT extracted from a large cohort of patients with pulmonary sarcoidosis. The estimated prevalence of cavitary sarcoidosis was 2.2%. Cavitary lesions developed in patients with severe and active sarcoidosis (serum angiotensin-converting enzyme [SACE] > or =2 times the upper limit of normal range: 63.6%). Twelve (52.2%) patients had evidence of radiographic stage IV, 9 of whom (75%) had persistently increased SACE. As found on HRCT, cavitary lesions were multiple in 21 patients (91.3%), including 5 patients with 10 or more cavities. The size of cavitary lesions was variable, with a median diameter of 20 mm (range, 11-100 mm). Follow-up was available for 20 patients with a median follow-up of 6.25 years (range, 6 months to 15 years). Seven patients (35%) experienced some type of complication related to cavitary lesions, including 6 episodes of hemoptysis in 5 patients and aspergilloma occurrence in 3 patients. As seen on HRCT, the evolution of the number and size of cavitary lesions was variable, with a complete resolution of the largest cavitary lesion in only 5 patients (25%). During follow-up, wall thickening was always associated with a further infectious complication. In summary, cavitary lesions are rare in pulmonary sarcoidosis and usually occur in active and severe sarcoidosis. Their evolution is unpredictable, and complications are frequent.

Diffusion-weighted whole-body imaging with background body signal suppression (DWIBS): features and potential applications in oncology

Diffusion-weighted magnetic resonance imaging (DWI) provides functional information and can be used for the detection and characterization of pathologic processes, including malignant tumors. The recently introduced concept of “diffusion-weighted whole-body imaging with background body signal suppression” (DWIBS) now allows acquisition of volumetric diffusion-weighted images of the entire body. This new concept has unique features different from conventional DWI and may play an important role in whole-body oncological imaging. This review describes and illustrates the basics of DWI, the features of DWIBS, and its potential applications in oncology.

Diffusion-weighted whole-body imaging with background body signal suppression (DWIBS): features and potential applications in oncology

Diffusion-weighted magnetic resonance imaging (DWI) provides functional information and can be used for the detection and characterization of pathologic processes, including malignant tumors. The recently introduced concept of "diffusion-weighted whole-body imaging with background body signal suppression" (DWIBS) now allows acquisition of volumetric diffusion-weighted images of the entire body. This new concept has unique features different from conventional DWI and may play an important role in whole-body oncological imaging. This review describes and illustrates the basics of DWI, the features of DWIBS, and its potential applications in oncology.

Evolving role of imaging modalities in inflammatory breast cancer

Imaging plays several key roles in the diagnosis and assessment of inflammatory breast cancer (IBC). These include characterization of the known tumor, delineation of locoregional disease in the ipsilateral and contralateral breast and regional lymph node basins, diagnosis of distant metastases, and evaluation of treatment response. We review the role of conventional imaging modalities, including mammography and sonography. We also discuss the potential of using evolving imaging modalities such as magnetic resonance imaging (MRI), positron emission tomography with computed tomography (PET/CT), and more advanced or emerging imaging techniques in the assessment of IBC.

Gliomas: predicting time to progression or survival with cerebral blood volume measurements at dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging

PURPOSE

To retrospectively determine whether relative cerebral blood volume (CBV) measurements can be used to predict clinical outcome in patients with high-grade gliomas (HGGs) and low-grade gliomas (LGGs) and specifically whether patients who have gliomas with a high initial relative CBV have more rapid progression than those who have gliomas with a low relative CBV.

MATERIALS AND METHODS

Approval for this retrospective HIPAA-compliant study was obtained from the Institutional Board of Research Associates, with waiver of informed consent. One hundred eighty-nine patients (122 male and 67 female patients; median age, 43 years; range, 4-80 years) were examined with dynamic susceptibility-weighted contrast material-enhanced perfusion magnetic resonance (MR) imaging and were followed up clinically with MR imaging (median follow-up, 334 days). Log-rank tests were used to evaluate the association between relative CBV and time to progression by using Kaplan-Meier curves. Binary logistic regression was used to determine whether age, sex, and relative CBV were associated with an adverse event (progressive disease or death).

RESULTS

Values for the mean relative CBV for patients according to each clinical response were as follows: 1.41 +/- 0.13 (standard deviation) for complete response (n = 4), 2.36 +/- 1.78 for stable disease (n = 41), 4.84 +/- 3.32 for progressive disease (n = 130), and 3.82 +/- 1.93 for death (n = 14). Kaplan-Meier estimates of median time to progression in days indicated that patients with a relative CBV of less than 1.75 had a median time to progression of 3585 days, whereas patients with a relative CBV of more than 1.75 had a time to progression of 265 days. Age and relative CBV were also independent predictors for clinical outcome.

CONCLUSION

Dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging can be used to predict median time to progression in patients with gliomas, independent of pathologic findings. Patients who have HGGs and LGGs with a high relative CBV (>1.75) have a significantly more rapid time to progression than do patients who have gliomas with a low relative CBV.

A preclinical model for predicting drug response in soft-tissue sarcoma with targeted AAVP molecular imaging

Human sarcomas are rare but diverse malignant tumors derived from mesenchymal tissue. Clinical response to therapy is currently determined by the modified World Health Organization (WHO) criteria or the Response Evaluation Criteria in Solid Tumors (RECIST), but these standards correlate poorly with sarcoma patient outcome. We introduced ligand-directed particles with elements of AAV and phage (AAVP) to enable integration of tumor targeting to molecular imaging. We report drug-response monitoring and prediction in a nude rat model of human sarcoma by AAVP imaging. As a proof-of-concept, we imaged Herpes simplex thymidine kinase in a clinic-ready setting with PET to show that one can a priori predict tumor response to a systemic cytotoxic. Given the target expression in patient-derived sarcomas, this platform may be translated in clinical applications. Sarcoma-specific ligands and promoters may ultimately lead to an imaging transcriptome.

Efficacy of primary systemic chemotherapy regimen containing anthracyclines with/without taxanes in comparison to CMF in women with early breast cancer

Neoadjuvant chemotherapy is the treatment of choice for locally-advanced breast cancer and leads to down staging and improved breast-conserving therapy (BCT) rates. While its efficacy is well established, considerably less is known about the most effective regimen. We have performed a retrospective analysis of 132 breast cancer patients who had undergone neoadjuvant chemotherapy at our institution. Patients had either received a) anthracyclines ("A", n=35), b) anthracyclines and taxanes ("AT", n=55), or c) neither of the two compounds ("NoA/T", n=42). Clinical response, pathological response and survival were evaluated in each arm. While all three regimens resulted in significant tumor regression, AT was most effective with a mean tumor shrinkage of 39% (ultrasound) and 41% (mammography) (Kruskal-Wallis, p=0.004, and p=0.027). Breast conservation was achieved in 75% by AT, in 49% by A, and in 19% by NoA/T (Kruskal-Wallis, p<0.001). The treatment groups did not differ in respect to pathological complete response (pCR) (chi2-test, p=0.068), although higher cumulative anthracycline doses were predictive of pCR in multivariate analyses (p=0.022). While the mammographic but not the ultrasound-determined tumor diameter determined whether a woman underwent BCT, only an ultrasound-determined size reduction was predictive for disease-free survival (DFS) and overall survival (OS) (log rank, p=0.0093, and p=0.044, respectively). Other parameters that affected BCT rates were age (p= 0.003), year of diagnosis (p=<0.001), presence of multifocal disease (p= 0.032) and the cumulative anthracycline dose (p= <0.001). While the combination of anthracyclines and taxanes is most effective in achieving clinical remission and BCT, the cumulative anthracycline dose appears most important for achieving pCR.