Diagnostic and therapeutic imaging for cancer: therapeutic considerations and future directions

As cancer treatment cost soar and the mantra for "personalized medicine" grows louder, we will increasingly be searching for solutions to these diametrically opposed forces. In this review we highlight several exciting novel imaging strategies including MRI, CT, PET SPECT, sentinel node, and ultrasound imaging that hold great promise for improving outcomes through detection of lymph node involvement. We provide clinical data that demonstrate how these evolving strategies have the potential to transform treatment paradigms.

Improving CT prediction of treatment response in patients with metastatic colorectal carcinoma using statistical learning theory

Background

Significant interest exists in establishing radiologic imaging as a valid biomarker for assessing the response of cancer to a variety of treatments. To address this problem, we have chosen to study patients with metastatic colorectal carcinoma to learn whether statistical learning theory can improve the performance of radiologists using CT in predicting patient treatment response to therapy compared with the more traditional RECIST (Response Evaluation Criteria in Solid Tumors) standard.

Results

Predictions of survival after 8 months in 38 patients with metastatic colorectal carcinoma using the Support Vector Machine (SVM) technique improved 30% when using additional information compared to WHO (World Health Organization) or RECIST measurements alone. With both Logistic Regression (LR) and SVM, there was no significant difference in performance between WHO and RECIST. The SVM and LR techniques also demonstrated that one radiologist consistently outperformed another.

Conclusions

This preliminary research study has demonstrated that SLT algorithms, properly used in a clinical setting, have the potential to address questions and criticisms associated with both RECIST and WHO scoring methods. We also propose that tumor heterogeneity, shape, etc. obtained from CT and/or MRI scans be added to the SLT feature vector for processing.

Improving CT prediction of treatment response in patients with metastatic colorectal carcinoma using statistical learning

To establish radiologic imaging as a valid biomarker for assessing the response of cancer to different treatments. We study patients with metastatic colorectal carcinoma to learn whether Statistical Learning Theory (SLT) improves the performance of radiologists using Computer Tomography (CT) in predicting patient treatment response to therapy compared with traditional Response Evaluation Criteria in Solid Tumours (RECIST) standard. Preliminary research demonstrated that SLT algorithms can address questions and criticisms associated with both RECIST and World Health Organization (WHO) scoring methods. We add tumour heterogeneity, shape, etc., obtained from CT or MRI scans the feature vector for processing.

Extent of disease burden determined with magnetic resonance imaging of the bone marrow is predictive of survival outcome in patients with multiple myeloma

BACKGROUND

Multiple myeloma (MM) remains an incurable cancer. Treatment often is initiated at the time patients experience a progressive increase in tumor burden. The authors of this report investigated magnetic resonance imaging of the bone marrow (BM-MRI) as a novel approach to quantify disease burden and validated a staging system by correlating BM-MRI with common clinical and laboratory parameters.

METHODS

The extent of bone marrow involvement was evaluated by BM-MRI. Clinical and laboratory parameters were assessed in patients with active MM, and correlations between variables were assessed statistically. Bone marrow involvement by BM-MRI was defined as stage A (0%), stage B (<10%), stage C (10%-50%), and stage D (>50%).

RESULTS

In total, 170 consecutive patients were evaluated (77 women and 93 men), including 144 patients who had active MM. The median age was 61 years (age range, 35-83 years). Advance stage disease (stage >I) based on Durie-Salmon (DS) staging or International Staging System (ISS) criteria was observed in 122 patients (84%) and 77 patients (53%), respectively. Lytic bone disease was noted in 120 patients (83%). There was a significant association between BM-MRI involvement and DS stage (P = .0006), ISS stage (P = .0001), the presence of lytic bone disease (P < .0001) and mean beta-2 microglobulin levels (P < .0001). Among the patients with previously untreated MM, there was a significant association between BM-MRI stage and overall survival (OS) (univariate P = .013; multivariate P = .045). Plasmacytosis on bone marrow biopsy at diagnosis was not predictive of OS (P = .91).

CONCLUSIONS

BM-MRI is a novel approach for quantifying disease burden in patients with MM. The current investigation in a large cohort of nontransplantion MM patients demonstrated that the extent of bone marrow involvement determined by BM-MRI correlates accurately with other conventional parameters of disease burden and can independently predict survival in patients with MM at the time of initial diagnosis.

New CT treatment response score for predicting survival in patients with metastatic colorectal carcinoma: A pilot study

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Background: To develop a methodology that results in an optimized CT Treatment Response Score (CTRS) for prediction of survival using quantified changing lesion features. Methods: We evaluated the overall survival (OS) predictive value of a new methodology to assess CT scan-based responses versus RECIST guidelines in a homogenous metastatic colorectal cancer population. All patients (pts) with MCRC treated with cetuximab and irinotecan (cet & irino) between 2005 and 2008 in our Center after failure of prior oxaliplatin and fluoropyrimidine were included in this analysis. Other inclusion criteria included: at least 6 weeks of cet & irino and serial CT scans on cet & irino including baseline performed in our Center. 38 pts (22 men, 16 women, mean age = 62, range = 28–91 ) were included. CT scans were interpreted by 2 trained physician assistants initially independently with differences resolved by consensus. Parameters evaluated included change in tumor size using standard RECIST and visual based (VB) assessment, VB assessment of enhancement, and interval development of new lesions.VB scoring used Likert-type scales to code reader confidence as to change in an imaging characteristic (size, enhancement) and the presence/absence of a characteristic (new lesions). The most predictive parameters for OS were used to generate the CTRS with an overall range of -2 (definite tumor decrease) to +2 (definite tumor increase). Results: The optimal CTRS resulted from combining VB assessment of change in size of existing lesions and new lesion development. This resulted in prediction of survival with a Cox Hazard Ratio of 1.639 (p = 0.0008). Using a threshold value of 0 to generate good (scores ≤ 0) and poor (scores > 0) response groups resulted in probabilities of survival at 8 months (ms) of 75% (16 pts) and 32% (22 pts), median survival times of 13.3 ms (95% CI = 10.94 ms, 17.81 ms) and 5.06 ms (95% CI = 3.84 ms, 8.77 ms), respectively. CTRS was easier to perform and appeared to be more predictive of OS outcome than RECIST. Conclusions: The methodology results in a single CTRS with transparent for others to test and understandable in terms of predicting survival for pts and caretakers. This methodology needs validation in a larger patient data set and across various tumors and lines of treatment.

No significant financial relationships to disclose.

Environmentalism unbound: reconnecting and re-envisioning movements for change

Disputes over environmental discourse have generated divergent pathways and discordant messages over the last three decades. An examination of them becomes a study of environmentalism s roots. The workplace is shown as a hidden and often discounted arena of debate about what constitutes an environmental issue. The triumph of the productionist and limitless consumption views helped to establish a focus on environmental change as a form of consumer action. Since the 1970s though, new forms of environmental discourse and action both community- and production-related have sought to shift the terrain. The possibility of becoming a broader, more socially inclusive movement capable of challenging the very structure and logic of capitalist social order is possible again, including the ability to identify new strategies for action. Overcoming the work/environment divide is perhaps the most contentious question facing the future of the environmental and labor movements. New approaches, including developing a community of interests, revaluing work, and developing an ethic of place (with urban, industrial, and global forms), require that the social and the ecological become joined in the construction of a common vision. When any environmental issue can be seen as socially determined, then environmentalism s great task will be to see itself as a primary agent of social change.

Does qualitative radiologic assessment of tumor response measure up to traditional quantitative scoring methods?

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Background: The Response Evaluation Criteria in Solid Tumors (RECIST) and World Health Organization (WHO) radiologic metrics are the standards for tumor response to therapy. However these methods are difficult to use and are limited in their prediction of clinical outcome. We hypothesize a simpler qualitative assessment of tumor response by CT is as reproducible and predictive of clinical outcome as the RECIST and WHO methods. Methods: This was a retrospective evaluation of 23 patients (11 males, 12 females, mean age 56.1 years, range 40–81 years) with biopsy proven metastatic colo-rectal carcinoma treated at our institution between 2002 and 2006 who did not have their primary tumor resected. Only patients with two consecutive CT examinations separated by at least three weeks were included. Two board certified radiologists, blinded to the other's reads, independently interpreted all CT examinations measuring up to five hepatic lesions on both CT examinations using RECIST and WHO criteria and qualitatively assessing all hepatic metastases, categorizing them as increased, decreased, or unchanged between scans. Clinical outcome, using time to progression of disease (TTP), was measured, utilizing a Cox proportional hazards model, to compare the predictive value of all three scoring systems for those patients starting first line chemotherapy (11 patients) at the time of our analysis. Results: Qualitative assessment resulted in agreement in 21/23 patients (91.3%, kappa = 0.78) classifying hepatic metastases as any increase (2 patients), any decrease (17 patients), or no change (2 patients) between scans compared with agreement in 20/23 patients (87.0%) for RECIST (kappa = 0.62) and WHO ( kappa = 0.67) methods placing patients into partial response (2 patients by RECIST and WHO), stable disease (17 patients by RECIST, 16 patients by WHO), and disease progression (1 patient by RECIST, 2 patients by WHO)categories by accepted criteria. No significant difference in prediction of TTP between methods was found. Conclusions: Our pilot data suggests our qualitative scoring system may be at least as reproducible and predictive of patient clinical outcome as the RECIST and WHO methods.

No significant financial relationships to disclose.

Ovarian cancer: comparison of observer performance for four methods of interpreting CT scans

PURPOSE

To assess the effects of four interpretative methods on observers' mean sensitivity and specificity by using computed tomography (CT) of ovarian carcinoma as a model.

MATERIALS AND METHODS

CT scans in 98 patients with ovarian carcinoma and 49 women who were disease free were retrospectively reviewed by four experienced blinded radiologists to compare single-observer reading, single-observer reading with an anatomic checklist, paired-observer reading (simultaneous double reading), and replicated reading (combination of two independent readings). Confidence level scoring was used to identify three possible disease forms in each patient: extranodal tumor, lymphadenopathy, and ascites. Patient conditions were then categorized as abnormal or normal.

RESULTS

There were no significant improvements in sensitivity or specificity for classification of patient conditions as abnormal or normal when comparing single-observer interpretation with single-observer interpretation with a checklist or paired-observer interpretation. Although there was no significant improvement in the mean sensitivity (93% vs 94%) by using the replicated reading method, there was a statistically significant improvement in mean specificity (85% vs 79%) for the replicated readings compared with single-observer interpretations (P < .05).

CONCLUSION

Diagnostic aids such as checklists and paired simultaneous readings did not lead to an improved mean observer performance for experienced readers. However, an increase in the mean specificity occurred with replicated readings.

New paradigm for lymphocyte granule-mediated cytotoxicity. Target cells bind and internalize granzyme B, but an endosomolytic agent is necessary for cytosolic delivery and subsequent apoptosis

Lymphocyte granule-mediated apoptosis is postulated to entail the formation of membrane pores by perforin. Then soluble granzyme reaches the cytosol either through these pores or by reparative pinocytosis. We demonstrate here that Jurkat cells bind and internalize granzyme B via high affinity binding sites without toxic consequence. Apoptosis occurs, however, if sublytic perforin is added to targets washed free of soluble granzyme B. We suggest that granule-mediated apoptosis mimics viral strategies for cellular entry. Accordingly, co-internalization of granzyme B with adenovirus, a virus that escapes endosomes to reach the cytosol, also induced apoptosis. Poly(ADP-ribose) polymerase cleavage and processing of CPP32, ICE-LAP3, and Mch2 were detected at 30 min, while cytosolic acidification and DNA fragmentation occurred at 60 min. Annexin V binding and membrane permeabilization arose at 4 h. The concurrent activation of the Ced-3 proteases differed from the rate at which each cysteine protease is cleaved in vitro by granzyme B. Thus, granzyme B may not directly process these proteases in whole cells but rather may function by activating a more proximal enzyme. These results indicate that adenovirus-mediated delivery of granzyme B is suitable for elucidating biochemical events that accompany granule-mediated apoptosis.

Depressive Experiences Questionnaire: An Empirical Exploration of the Underlying Theory

This article addresses the theoretical conceptualization of depressive typology proposed by Blatt (1974) by analyzing selected items on the Depressive Experiences Questionnaire (DEQ) in a 21-item modified version. Items were selected by judges and by factor loading criteria to be most theoretically characteristic of the dimensions they are meant to represent: anaclitic and introjective depression. Two independent samples, a female inpatient sample and a female college sample, were used. Principal components analysis of these 21 items revealed only 5 anaclitic items and 7 introjective items that loaded on their respective factors for both samples. Inspection of these items suggests that the anaclitic depressive experience is characterized by discomfort with interpersonal separation, whereas the introjective experience is characterized by negative self-evaluation with respect to self-imposed standards. Other putative aspects of these two depressive dimensions were not supported by this study; particularly, guilt and self-blame were not associated with introjective depression.

Bleeding complications with the chimeric antibody to platelet glycoprotein IIb/IIIa integrin in patients undergoing percutaneous coronary intervention. EPIC Investigators

BACKGROUND

The potential for novel antiplatelet and antithrombin agents to contribute to periprocedural bleeding complications of percutaneous coronary revascularization is poorly defined. In the Evaluation of c7E3 Fab in Preventing Ischemic Complications of High-Risk Angioplasty (EPIC) trial, the periprocedural use of aspirin, heparin, and a chimeric antibody to the platelet glycoprotein IIb/IIIa integrin c7E3 Fab in 2099 patients significantly reduced postprocedural ischemic complications and 6-month clinical restenosis but was associated with increased procedural bleeding complications. We review these complications and describe clinical and procedural variables associated with increased bleeding complications in the EPIC trial.

METHODS AND RESULTS

Patients with high-risk clinical or lesion morphological characteristics were randomized to receive placebo bolus plus placebo infusion, c7E3 Fab bolus plus placebo infusion, or c7E3 Fab bolus plus c7E3 Fab infusion. Patients received periprocedural aspirin and intravenous heparin continued for a minimum of 12 hours after the procedure. Outcomes reflecting bleeding complications were measured: transfusions, decreased hemoglobin, and an index including both parameters. Major bleeding complications unrelated to bypass surgery occurred in 3.3%, 8.6%, and 10.6%, and blood product transfusions were used in 7.5%, 14.0%, and 16.8% of patients treated with placebo, bolus c7E3 Fab, and bolus plus infusion c7E3 Fab, respectively (both P < .001). Most major bleeding complications occurred at the femoral access site, regardless of treatment. Intracranial hemorrhage (0.3%) and death (0.09%) attributable to major bleeding complications were rare. Multivariable regression analyses identified several variables significantly and independently related to major bleeding complications or greater blood loss, including greater age, female sex, lower weight, c7E3 Fab therapy, and duration and complexity of the index procedure. Major bleeding complications and blood loss in patients receiving bolus plus infusion were not significantly greater than in those receiving bolus alone (P = .38 and P = .14, respectively).

CONCLUSIONS

Bleeding complications unrelated to bypass surgery were two to three times more frequent in patients receiving c7E3 Fab than in those receiving placebo, but most were transient and well tolerated. Risk-factor analysis and modification of concomitant antithrombotic and antiplatelet treatment strategies may aid in reducing bleeding complications and enhancing clinical benefit in patients receiving c7E3 Fab during percutaneous coronary revascularization.

Low molecular weight heparin in prevention of restenosis after angioplasty. Results of Enoxaparin Restenosis (ERA) Trial

BACKGROUND

Heparin, an anticoagulant, possesses antiproliferative effects and has been shown to reduce neointimal proliferation and restenosis following vascular injury in experimental studies.

METHODS AND RESULTS

The primary aim of this double-blind multicenter study was to determine if 40 mg Enoxaparin, a low molecular weight heparin, administered subcutaneously once daily for 1 month after successful angioplasty would reduce the incidence of restenosis. Four hundred fifty-eight patients were randomized at nine clinical centers (231 to placebo and 227 to Enoxaparin). The primary end point was angiographic or clinical restenosis. Angiographic restenosis was defined as a loss of 50% of the initial gain as measured by quantitative coronary angiography (QCA) at a core laboratory. In the absence of QCA, clinical evidence of restenosis was defined as death, myocardial infarction, repeat revascularization, or worsening angina. Using the intention-to-treat analysis for all patients, restenosis occurred in 51% of the placebo group and 52% of the Enoxaparin group (relative risk, 1.07, P = .625). Likewise, no difference in restenosis was evident when the change in minimal lumen diameter or other angiographic definitions of restenosis were used. Adverse clinical events were infrequent and did not differ between the groups with the exception of minor bleeding complications, which were more common in the Enoxaparin group.

CONCLUSIONS

Enoxaparin (40 mg/d SC for 1 month) following successful angioplasty did not reduce the incidence of angiographic restenosis or the occurrence of clinical events over 6 months. The treatment was well tolerated, although in-hospital minor bleeding was more common with active treatment.

Myelographic and enhanced computed tomographic appearance of acute traumatic spinal cord avulsion

The neuroradiological findings that revealed spinal cord transection/laceration in 6 patients with acute, blunt spinal trauma are described. Four patients suffered cervical spine injuries, and two had thoracic injuries. Initially, all patients had complete neurological deficit at the level of injury. The deficit improved in only 1 patient. On the basis of clinical history and spinal radiographs, spinal hyperflexion with distraction was the predominant mechanism of injury in our patients. Computed tomography with intrathecal contrast was performed on all patients and was always diagnostic. Visualization of intrathecal contrast material accumulating within the cord or the absence of cord shadow within the contrast column established the diagnosis in all cases. A dural tear was noted in 3 patients. Thoracic myelography was performed in 2 patients and, in both, demonstrated contrast pooling within the spinal cord at the level of the laceration. Magnetic resonance imaging was obtained in 1 patient and revealed an irregular, low-signal-intensity, intramedullary region extending to the cord surface on T1-weighted axial images. The myelographic and enhanced computed tomographic appearances of acute, traumatic spinal cord avulsion/laceration, which have been infrequently reported in the literature, are described.

Coronary angiographic assessment of left posterior hemiblock

The ECGs of 1,095 patients with coronary angiographic evidence of significant coronary artery disease (greater than or equal to 50% obstructive lesion in at least one major coronary artery) were reviewed. Five patients had left posterior hemiblock (LPHB), an incidence of 0.5%. Three of five patients also had a right bundle branch block (RBBB). Of the five patients with LPHB, all had significant right coronary artery (RCA) disease (four complete occlusions, one 90% obstructive lesion). All five patients having LPHB also had evidence of critical disease (greater than or equal to 75% obstruction) of at least one of the major branches of the left coronary artery; four of the five had complete occlusion of the left anterior descending coronary artery (LAD). The left circumflex coronary artery (CFx) was critically diseased in three patients. The ECGs of four patients showed evidence of only one myocardial infarction while one patient had evidence of an anterior and an inferior infarction. It is concluded that the presence of LPHB in patients with coronary artery disease is an ominous electrocardiographic finding, and is associated with extensive coronary artery disease.

Corynebacterium parvum versus BCG adjuvant immunotherapy in human malignant melanoma

One-hundred and sixteen patients with Stage I and Stage II malignant melanoma were randomized to treatment with either Bacillus Calmette-Guerin (BCG) (Tice) or subcutaneous Corynebacterium parvum (Burroughs-Wellcome). Life table analysis failed to reveal a difference between these two forms of treatment in 68 Stage I patients. The relapse rate was significantly reduced in Stage II patients treated with C. parvum.

Lactate metabolism as a prognostic index in unstable angina

Fifty patients evaluated because of unstable angina were followed up for a mean period of 63.7 months. Analysis of transmyocardial lactate metabolism was performed in all patients in addition to coronary angiography and ventriculography. All patients had at least one coronary lesion of great than 75%. Although technically feasible, aortocoronary bypass surgery was not performed on initial hospitalization and all patients were treated medically. Patients were divided into two groups on the basis of lactate metabolism; group A lactate production great than 15%, group B lactate production less than 15% or lactate extraction. There was no difference in left ventricular end-diastolic pressure or ejection fraction between the two groups. A coronary score index was higher in group A than group B (5.45 +/- 2.2 vs 3.13 +/- 1.2) (p less than 0.05). The incidence of myocardial infarction was higher in group A than group B in hospital (44.4% vs. 4.3%, p less than 0.05), and long term (70.3% vs. 17.3%, p less than 0.05). Mortality was higher in group A than group B in hospital (25.9% vs. 0%, p less than 0.05) and long term (66.7% vs. 13%, p less than 0.05). Analysis of lactate metabolism thus provides a prognostic index in unstable angina which complements information obtained by coronary angiography and ventriculography.

Phase II trial of cyclophosphamide, hexamethylmelamine, adriamycin, and cis-dichlorodiammineplatinum(II) combination chemotherapy in advanced ovarian carcinoma

A monthly four-drug regimen of cyclophosphamide, adriamycin, and cis-dichlorodiammineplatinum(II), each given iv of Day 1, and hexamethylmelamine, given orally on Days 1--14 (CHAP), was administered to 39 women with advanced epithelial ovarian carcinoma who had previously failed alkylating agent therapy. Of 35 evaluable patients with a measurable disease parameter, seven (20%) achieved a clinical complete response and ten (29%) achieved a clinical partial response. The median duration of complete response is greater than 9 months and the median duration of partial response is 4 months. Ninety percent of the patients required dose adjustments because of profound leukopenia, thrombocytopenia, or gastrointestinal intolerance. CHAP is an active but toxic regimen in the management of advanced ovarian cancer. The toxicity encountered reflected the intensity of the drug schedule as well as the combined influences of advanced stage of disease, poor nutritional and performance status, and prior therapy. The efficacy of this CHAP regimen warrants a controlled trial compared to other active drug programs.

Improved survival after coronary bypass surgery in patients with poor left ventricular function: role of intraaortic balloon counterpulsation

The operative mortality rate of aortocoronary bypass surgery in 23 patients with poor left ventricular function (ejection fraction 0.30 or less) operated on in 1973-74 was 34.7 percent. The incidence rate of operative myocardial infarction was 30.4 percent. In an attempt to improve survival, intraaortic balloon counterpulsation was used therafter in 25 similar patients. Counterpulsation was instituted preoperatively and continued intra- and postoperatively for 2 to 5 days. Preoperative studies revealed an "unloading" effect of the left ventricle, with significant reductions of systolic arterial blood pressure, end-diastolic pulmonary arterial pressure and end-diastolic left ventricular volume and pressure. Metabolic improvement was demonstrated by the lesser production of myocardial lactate after pacing-induced tachycardia when the ventricle was balloon-assisted. Intraoperatively, blood flow through the vein graft was found to increase with counterpulsation. The rate of operative myocardial infarction was reduced to 4 percent and the mortality rate to 8 percent. In patients who have sustained a significant loss of functioning myocardium, the beneficial hemodynamic and metabolic effects of intraaortic balloon counterpulsation appear to prevent furhter, possibly critical, myocardial damage in the perioperative period.