Image-aided estimate of tumor burden in Hodgkin's disease: evidence of its primary prognostic importance

Axicabtagene ciloleucel vs standard of care in second-line large B-cell lymphoma: outcomes by metabolic tumor volume

ABSTRACT

Metabolic tumor volume (MTV) assessed using 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography, a measure of tumor burden, is a promising prognostic indicator in large B-cell lymphoma (LBCL). This exploratory analysis evaluated relationships between baseline MTV (categorized as low [median or less] vs high [greater than median]) and clinical outcomes in the phase 3 ZUMA-7 study (NCT03391466). Patients with LBCL relapsed within 12 months of or refractory to first-line chemoimmunotherapy were randomized 1:1 to axicabtagene ciloleucel (axi-cel; autologous anti-CD19 chimeric antigen receptor T-cell therapy) or standard care (2-3 cycles of chemoimmunotherapy followed by high-dose chemotherapy with autologous stem cell transplantation in patients who had a response). All P values are descriptive. Within high- and low-MTV subgroups, event-free survival (EFS) and progression-free survival (PFS) were superior with axi-cel vs standard care. EFS in patients with high MTV (vs low MTV) was numerically shorter with axi-cel and was significantly shorter with standard care. PFS was shorter in patients with high MTV vs low MTV in both the axi-cel and standard-care arms, and median MTV was lower in patients in ongoing response at data cutoff vs others. Median MTV was higher in patients treated with axi-cel who experienced grade ≥3 neurologic events or cytokine release syndrome (CRS) than in patients with grade 1/2 or no neurologic events or CRS, respectively. Baseline MTV less than or equal to median was associated with better clinical outcomes in patients receiving axi-cel or standard care for second-line LBCL. The trial was registered at www.clinicaltrials.gov as #NCT03391466.

A different perspective on PET/CT before treatment in patients with Hodgkin lymphoma: importance of volumetric and dissemination parameters

The aim of this study is to investigate the role of the combination of volumetric and dissemination parameters obtained from pretreatment 18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in predicting the interim response and progression status in patients with Hodgkin lymphoma (HL). Pretreatment PET/CT images of HL patients were analyzed with LIFEx software, and volumes of interest (VOIs) were drawn with a fixed SUV 4.0 threshold. MTV, SUVmax, and TLG values were obtained from each VOI. Total MTV (tMTV) was calculated by summing the MTV values in all VOIs, and similarly, total TLG (tTLG) was obtained by summing the TLG values. The distance between the centers of the lesions was noted as Dmax, and the distance between the outermost voxels of the lesions as DmaxVox. tMTV/DmaxVox was calculated by dividing the tMTV value by the DmaxVox value, and tTLG/DmaxVox was calculated by dividing the tTLG value by the DmaxVox value. The correlation of pretreatment PET parameters with response groups (complete/poor) and relapse/progression status (stable/progressive) was statistically evaluated. A total of 52 patients were included in the study. Bulky disease, tMTV, tTLG, and tMTV/DmaxVox values were found to be significantly higher in the poor response group. tMTV > 190.60 ml was found to be the only prognostic factor predicting interim PET response. The tMTV/DmaxVox and tTLG/DmaxVox showed statistically significant differences between the groups with and without progression. tMTV/DmaxVox > 7.70 was found to be the only prognostic factor in predicting relapse/progression. The evaluation of tumor burden and dissemination together in 18F-FDG PET/CT before treatment in patients with HL can help us to predict the results of the patients.

Baseline metabolic tumour burden improves risk stratification in Hodgkin lymphoma: A Children's Oncology Group study

The Children's Oncology Group AHOD0831 study used a positron emission tomography (PET) response-adapted approach in high-risk Hodgkin lymphoma, whereby slow early responders (SERs) received more intensive therapy than rapid early responders (RERs). We explored if baseline PET-based characteristics would improve risk stratification. Of 166 patients enrolled in the COG AHOD0831 study, 94 (57%) had baseline PET scans evaluable for quantitative analysis. For these patients, total body metabolic tumour volume (MTV), total lesion glycolysis (TLG), maximum standardized uptake value (SUVmax ) and peak SUV (SUVpeak ) were obtained. MTV/TLG thresholds were an SUV of 2.5 (MTV2.5 /TLG2.5 ) and 40% of the tumour SUVmax (MTV40% /TLG40% ). TLG2.5 was associated with event-free survival (EFS) in the complete cohort (p = 0.04) and in RERs (p = 0.01), but not in SERs (p = 0.8). The Youden index cut-off for TLG2.5 was 1841. Four-year EFS was 92% for RER/TLG2.5  up to 1841, 60% for RER/TLG2.5  greater than 1841, 74% for SER/TLG2.5  up to 1841 and 79% for SER/TLG2.5  greater than 1841. Second EFS for RER/TLG2.5  up to 1841 was 100%. Thus, RERs with a low baseline TLG2.5 experienced excellent EFS with less intensive therapy, whereas RERs with a high baseline TLG2.5 experienced poor EFS. These findings suggest that patients with a high upfront tumour burden may benefit from intensified therapy, even if they achieve a RER.

PET/CT in Hodgkin Lymphoma: An Update

¹⁸F-FDG-PET/CT is now an integral part of the workup and management of patients with Hodgkin's lymphoma (HL). PET/CT is currently routinely performed for staging and for response assessment at the end of treatment. Interim PET/CT is typically performed after 1-4 of 6-8 chemo/chemoimmunotherapy cycles ± radiation for prognostication and potential treatment escalation or de-escalation early in the course of therapy, a concept known as response-or risk-adapted treatment. Quantitative PET is an area of growing interest. Metrics such as the standardized uptake value (SUV), metabolic tumor volume, total lesion glycolysis, and their changes with treatment are being investigated as more reproducible and, potentially, more accurate predictors of response and prognosis. Despite the progress made in standardizing the use of PET/CT in lymphoma, challenges remain, particularly with respect to its limited positive predictive value. This review highlights the most relevant applications of PET/CT in HL, its strengths and limitations, as well as recent efforts to implement PET/CT-based metrics as promising tools for precision medicine. Finally, the value of PET/CT for response assessment to immunotherapy is discussed.

Imaging to predict checkpoint inhibitor outcomes in cancer. A systematic review

BACKGROUND

Checkpoint inhibition has radically improved the perspective for patients with metastatic cancer, but predicting who will not respond with high certainty remains difficult. Imaging-derived biomarkers may be able to provide additional insights into the heterogeneity in tumour response between patients. In this systematic review, we aimed to summarise and qualitatively assess the current evidence on imaging biomarkers that predict response and survival in patients treated with checkpoint inhibitors in all cancer types.

METHODS

PubMed and Embase were searched from database inception to 29th November 2021. Articles eligible for inclusion described baseline imaging predictive factors, radiomics and/or imaging machine learning models for predicting response and survival in patients with any kind of malignancy treated with checkpoint inhibitors. Risk of bias was assessed using the QUIPS and PROBAST tools and data was extracted.

RESULTS

In total, 119 studies including 15,580 patients were selected. Of these studies, 73 investigated simple imaging factors. 45 studies investigated radiomic features or deep learning models. Predictors of worse survival were (i) higher tumour burden, (ii) presence of liver metastases, (iii) less subcutaneous adipose tissue, (iv) less dense muscle and (v) presence of symptomatic brain metastases. Hazard rate ratios did not exceed 2.00 for any predictor in the larger and higher quality studies. The added value of baseline fluorodeoxyglucose positron emission tomography parameters in predicting response to treatment was limited. Pilot studies of radioactive drug tracer imaging showed promising results. Reports on radiomics were almost unanimously positive, but numerous methodological concerns exist.

CONCLUSIONS

There is well-supported evidence for several imaging biomarkers that can be used in clinical decision making. Further research, however, is needed into biomarkers that can more accurately identify which patients who will not benefit from checkpoint inhibition. Radiomics and radioactive drug labelling appear to be promising approaches for this purpose.

Pre-treatment total metabolic tumour volumes in lymphoma: Does quantity matter?

Positron emission tomography/computed tomography (PET/CT) is used for the staging of lymphomas. Clinical information, such as Ann Arbor stage and number of involved sites, is derived from baseline staging and correlates with tumour volume. With modern imaging software, exact measures of total metabolic tumour volumes (tMTV) can be determined, in a semi- or fully-automated manner. Several technical factors, such as tumour segmentation and PET/CT technology influence tMTV and there is no consensus on a standardized uptake value (SUV) thresholding method, or how to include the volumes in the bone marrow and spleen. In diffuse large B-cell lymphoma, follicular lymphoma, peripheral T-cell lymphoma, and Hodgkin lymphoma, tMTV has been shown to predict progression-free survival and/or overall survival, after adjustments for clinical risk scores. However, most studies have used receiver operating curves to determine the optimal cut-off for tMTV and many studies did not include a training-validation approach, which led to the risk of overestimation of the independent prognostic value of tMTV. The identified cut-off values are heterogeneous, even when the same SUV thresholding method is used. Future studies should focus on testing tMTV in homogeneously-treated cohorts and seek to validate identified cut-off values externally so that a prognostic value can be documented, over and above currently used clinical surrogates for tumour volume.

FDG-PET/CT in Lymphoma: Where Do We Go Now?

18F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) is an essential part of the management of patients with lymphoma at staging and response evaluation. Efforts to standardize PET acquisition and reporting, including the 5-point Deauville scale, have enabled PET to become a surrogate for treatment success or failure in common lymphoma subtypes. This review summarizes the key clinical-trial evidence that supports PET-directed personalized approaches in lymphoma but also points out the potential place of innovative PET/CT metrics or new radiopharmaceuticals in the future.

Total tumor burden in lymphoma - an evolving strong prognostic parameter

Total metabolic tumor volume (TMTV), a new parameter extracted from baseline FDG-PET/CT, has been recently proposed by several groups as a prognosticator in lymphomas before first-line treatment. TMTV, the sum of the metabolic volume of each lesion, is an index of the metabolically most active part of the tumor and highly correlates with the total tumor burden. TMTV measurement is obtained from PET images processed with different software and techniques, many being now freely available. In the various lymphoma subtypes where it has been measured, such as diffuse large B-cell lymphoma, Hodgkin lymphoma, Follicular Lymphoma, and Peripheral T-cell lymphoma, TMTV has been reported as a strong predictor of outcome (progression-free survival and overall survival) often outperforming the clinical scores, molecular predictors, and results of interim PET. Combined with these scores, TMTV improves the stratification of the populations into risk groups with different outcomes. TMTV cut-off separating the high-risk from the low-risk population impacts the outcome whatever the technique used for its measurement and an international harmonization is ongoing. TMTV is a unique and easy tool that could replace the surrogate of tumor burden included in the prognostic indexes used in lymphoma and help tailor therapy. Other parameters extracted from the baseline PET may give an information on the dissemination of this total tumor volume such as the maximum distance between the lesions. Trials based on TMTV would probably demonstrate its predictive value.

The presence of a bulky mediastinal mass of 7 cm or greater in diameter confers an adverse prognosis to patients with advanced Hodgkin lymphoma in case of negative interim PET/CT

In the PET-adapted therapy era, a bulky mediastinal mass (BMM) is not considered a risk factor in patients with advanced-stage Hodgkin lymphoma (HL). The current retrospective study aimed to estimate the prognostic significance of BMM presence and size for disease-free survival (DFS) and determine the most accurate mass size cutoff (among 5 cm, 7 cm, 10 cm) to predict inferior DFS in such patients. The study included 196 advanced-HL patients treated at Rambam (n = 121) and Memorial Sloan Kettering Cancer Center (n = 75) between 2002 and 2016. At a median follow-up of 66.5 (1-222) months, 36 relapses occurred. In multivariate analysis, only the cutoff of 7 cm predicted inferior DFS and PFS (p < 0.007 and <0.038, respectively) in interim PET/CT (PET-2) negative (79%) patients. This study identifies the BMM size cutoff of 7 cm in any plane as most precise in predicting adverse prognosis in PET-2-negative patients with advanced-stage HL. More aggressive initial chemotherapy than ABVD improves such prognosis.

The predictive value of pre-treatment 18F-FDG PET/CT on treatment outcome in early-stage extranodal natural killer/T-cell lymphoma

The diagnostic value of pretreatment ¹⁸F-FDG PET/CT in early-stage extranodal natural killer/T-cell lymphoma (ENKTL) is established, but its prognostic value is still unclear. We conducted ¹⁸F-FDG PET/CT-based quantitative and qualitative analysis as well as assessed related clinical parameters in 50 patients with recently diagnosed ENKTL and treated with methotrexate, etoposide, dexamethasone, and pegaspargase (MESA)-based therapy. Patients were followed-up for 38.6 ± 17.8 months. Six patients died of tumor-related disease, and six patients presented with persistence or recurrence. The estimates of the 2-year OS and PFS for the patients were 90.0% (SE: 4.0%) and 82.0% (SE: 5.0%), respectively. Survival curves were obtained using Kaplan-Meier analysis and compared using log rank test. Based on signifiacnt results of univariate analysis, we selected Epstein-Barr virus DNA (EB-DNA), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for multivariate analysis. Finally, MTV was found to be the significant independent predictor of both OS (p = .038) and PFS (p = .039).

Modeling Tumor Evolutionary Dynamics to Predict Clinical Outcomes for Patients with Metastatic Colorectal Cancer: A Retrospective Analysis

Over 50% of colorectal cancer patients develop resistance after a transient response to therapy. Understanding tumor resistance from an evolutionary perspective leads to better predictions of treatment outcomes. The objectives of this study were to develop a computational framework to analyze tumor longitudinal measurements and recapitulate the individual evolutionary dynamics in metastatic colorectal cancer (mCRC) patients. A stochastic modeling framework was developed to depict the whole spectrum of tumor evolution prior to diagnosis and during and after therapy. The evolutionary model was optimized using a nonlinear mixed effect (NLME) method based on the longitudinal measurements of liver metastatic lesions from 599 mCRC patients. The deterministic limits in the NLME model were applied to optimize the stochastic model for each patient. Cox proportional hazards models coupled with the least absolute shrinkage and selection operator (LASSO) algorithm were applied to predict patients' progression-free survival (PFS) and overall survival (OS). The stochastic evolutionary model well described the longitudinal profiles of tumor sizes. The evolutionary parameters optimized for each patient indicated substantial interpatient variability. The number of resistant subclones at diagnosis was found to be a significant predictor to survival, and the hazard ratios with 95% CI were 1.09 (0.79-1.49) and 1.54 (1.01-2.34) for patients with three or more resistant subclones. Coupled with several patient characteristics, evolutionary parameters strongly predict patients' PFS and OS. A stochastic computational framework was successfully developed to recapitulate individual patient evolutionary dynamics, which could predict clinical survival outcomes in mCRC patients. SIGNIFICANCE: A data analysis framework depicts the individual evolutionary dynamics of mCRC patients and can be generalized to project patient survival outcomes.

PET-Derived Quantitative Metrics for Response and Prognosis in Lymphoma

Lymphoma is a potentially curable disease; however, the clinical challenge lies in further improvement of outcomes. PET with fludeoxyglucose is an effective imaging tool. PET-derived quantitative metrics have raised significant interest to be used as a prognostic factor to complement clinical parameters for treatment decisions. The most optimized use of these quantitative PET metrics, however, will be possible with the standardization of imaging procedures. In this article, we review the technical and methodological considerations related to PET-derived quantitative metrics, and the relevant published data to emphasize the potential value of these metrics in patient prognosis and treatment response in lymphoma.

The pretreatment erythrocyte sedimentation rate predicts survival outcomes after surgery and adjuvant radiotherapy for extremity soft tissue sarcoma

Background

Systemic inflammation plays a critical role in cancer progression and oncologic outcomes in cancer patients. We investigated whether preoperative inflammatory biomarkers, including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and neutrophil to lymphocyte ratio (NLR), could be surrogate biomarkers for predicting overall survival (OS) in soft tissue sarcoma (STS) patients treated with surgery and postoperative radiotherapy.

Methods

A series of 99 patients who presented with localized extremity STS were retrospectively reviewed. The preoperative CRP levels, ESR, and NLR were evaluated for associations with OS, disease-free survival (DFS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS). Cutoff values for CRP, ESR, and NLR were derived from receiver-operating characteristic curve analysis.

Results

Elevated CRP (> 0.14 mg/dL), ESR (> 15 mm/h), and NLR (> 1.95) levels were seen in 33, 44, and 45 patients, respectively. Of these three inflammatory biomarkers, elevated CRP and ESR were associated with a poorer OS (CRP: P = 0.050; ESR: P = 0.001), DFS (CRP: P = 0.023; ESR: P = 0.003), and DMFS (CRP: P = 0.015; ESR: P = 0.001). By multivariate analysis, an elevated ESR was found to be an independent prognostic factor for OS (HR 3.580, P = 0.025) and DMFS (HR 3.850, P = 0.036) after adjustment for other established prognostic factors.

Conclusions

The preoperative ESR level is a simple and useful surrogate biomarker for predicting survival outcomes in STS patients and might improve the identification of high-risk patients of tumor relapse in clinical practice.

Volumetric assessment of mediastinal lymphoma masses in Hodgkin lymphoma

The large mediastinal mass (LMM) at initial staging represents a risk factor in Hodgkin lymphoma (HL) and is measured by X-ray. Depending on location of the LMM, different results can occur regardless of the initial lymphoma volume. To assess this risk factor more accurately, we evaluated the method of volumetry in 77 patients of HD13/14 study of the German Hodgkin Study Group. Furthermore, volume calculations based on three or only one diameter, were performed to simplify volume assessment. Inter-rater reliability was good for all methods. The 3-diameter measurement produced larger volumes than volumetric assessment with an intraclass correlation coefficient (ICC) of 0.93, which could be improved to 0.95 by multiplying volumes with a correction factor of 0.86. The 1-dimensional measurement strongly overestimated the volume with an ICC of 0.7. In conclusion, the simplified volume estimation based on 3 largest diameters provides a reliable concept for the staging of HL patients.

The role of PET/CT in the modern treatment of Hodgkin lymphoma

Classical Hodgkin Lymphoma is distinguished from other lymphomas by its peculiar biology and heterogeneous chemosensitivity. Most of the patients respond to the standard first-line treatment and are cured, however, in selected cases, the disease relapses or remains primarily refractory. Among predictive/prognostic factors ¹⁸FDG positron emission tomography (PET), fully integrated with computed tomography (PET/CT) proved to be extremely useful in identifying patients with poor prognosis at the time of diagnosis, during and at the end of treatment. The aim of this review is to present the current role of PET/CT in cHL at staging, interim and end of therapy assessment and its ability to guide treatment with a response- and risk-adapted strategy in clinical practice. Finally, quantitative PET measurement and the concurrent use of PET with selected biomarkers are discussed.

Time to Prepare for Risk Adaptation in Lymphoma by Standardizing Measurement of Metabolic Tumor Burden

Increased tumor burden is associated with inferior outcomes in many lymphoma subtypes. Surrogates of tumor burden that are easy to measure, such as the maximum tumor dimension of the bulkiest lesion on CT, have been used as prognostic indices for many years. Recently, total metabolic tumor volume (MTV) and tumor lesion glycolysis have emerged as promising and robust biomarkers of outcome in various lymphomas. The median MTV and the optimal cutoffs to separate patients into risk groups in a study population are, however, highly dependent on the population characteristics and the delineation method used to outline tumor on the PET image. This issue has precluded the use of MTV for risk stratification in trials and clinical practice. Standardization of the methodology is timely to allow the potential for risk adaptation to be explored in addition to response adaptation using PET. Meetings between representatives from research groups active in the field were held under the auspices of the PET International Lymphoma and Myeloma Workshop. A summary of those discussions, which included a review of the literature and a practical assessment of methods used for outlining, including various software options, is presented. Finally, a proposal is made to perform a technical validation of MTV measurement enabling benchmark reference ranges to be derived for published delineation approaches used for outlining with various software. This process would require collation of representative imaging data sets of the most common lymphoma subtypes; agreement on pragmatic criteria for the selection of lesions; generation of a range of MTVs, with consensus to be reached on final contours in a training set; and development of automated software solutions with a set of minimum functionalities to reduce measurement variability. Methods developed in the above training exercise could then be applied to another data set, with a final set of contours and values generated. This final data set would provide a benchmark against which end-users could test their ability to measure MTVs that are consistent with expected values. The data set and automated software solutions could be shared with manufacturers with the aim of including these in standard workflows to allow standardization of MTV measurement across the world.

Role of FDG PET-CT in the treatment management of Hodgkin lymphoma

Fluorodeoxyglucose (FDG) positons emission tomography (PET)-computed tomography (CT) is used in many ways at baseline and during the treatment of patients with Hodgkin lymphoma. Many properties of the technique are used in the different steps of patient's management. Initial staging with PET-CT is more accurate than conventional imaging and PET-CT also became the gold standard imaging at the end of treatment with a negative PET-CT mandatory for reaching a complete remission. Early assessment of response by PET-CT is one of the most powerful prognostic factors for progression-free survival of patients with localized and advanced stages and allows guiding treatment. Conversely, previous studies showed that there is no role of FDG PET-CT for the patient's follow-up.

Metabolic Tumor Volume Metrics in Lymphoma

Although visual assessment using the Deauville criteria is strongly recommended by guidelines for treatment response monitoring in all FDG-avid lymphoma histologies, the high rate of false-positives and concerns about interobserver variability have motivated the development of quantitative tools to facilitate objective measurement of tumor response in both routine and clinical trial settings. Imaging studies using functional quantitative measures play a significant role in profiling oncologic processes. These quantitative metrics allow for objective end points in multicenter clinical trials. However, the standardization of imaging procedures including image acquisition parameters, reconstruction and analytic measures, and validation of these methods are essential to enable an individualized treatment approach. A robust quality control program associated with the inclusion of proper scanner calibration, cross-calibration with dose calibrators and across other scanners is required for accurate quantitative measurements. In this section, we will review the technical and methodological considerations related to PET-derived quantitative metrics and the relevant published data to emphasize the potential value of these metrics in the prediction of patient prognosis in lymphoma.

[18F]FDG-PET/CT in Hodgkin Lymphoma: Current Usefulness and Perspectives

Functional imaging using 18-fluorodeoxyglycose ([¹⁸F]FDG) positron emission tomography combined with computed tomography (PET/CT) has become a major imaging modality in Hodgkin lymphoma. This imaging modality allows for a significant improvement in staging, increased sensitivity, which involves differentiating residual tumors from fibrosis during assessment, and highly impacts treatment decisions into new PET-driven strategies. This review presents the main scientific data concerning the current applications of [¹⁸F]FDG-PET/CT in Hodgkin lymphoma at baseline, interim, and the end of treatment evaluation along with the main PET-driven trials for therapeutic decisions. The emergence of total metabolic tumor volume as a new functional prognostic factor will also be discussed.

Prognostic value of baseline metabolic tumor volume in early-stage Hodgkin lymphoma in the standard arm of the H10 trial

We tested baseline positron emission tomography (PET)/computed tomography (CT) as a measure of total tumor burden to better identify high-risk patients with early-stage Hodgkin lymphoma (HL). Patients with stage I-II HL enrolled in the standard arm (combined modality treatment) of the H10 trial (NCT00433433) with available baseline PET and interim PET (iPET2) after 2 cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine were included. Total metabolic tumor volume (TMTV) was measured on baseline PET. iPET2 findings were reported negative (DS1-3) or positive (DS4-5) with the Deauville scale (DS). The prognostic value of TMTV was evaluated and compared with baseline characteristics, staging classifications, and iPET2. A total of 258 patients were eligible: 101 favorable and 157 unfavorable. The median follow-up was 55 months, with 27 progression-free survival (PFS) and 12 overall survival (OS) events. TMTV was a prognosticator of PFS (P < .0001) and OS (P = .0001), with 86% and 84% specificity, respectively. Five-year PFS and OS were 71% and 83% in the high-TMTV (>147 cm³) group (n = 46), respectively, vs 92% and 98% in the low-TMTV group (≤147 cm³). In multivariable analysis including iPET2, TMTV was the only baseline prognosticator compared with the current staging systems proposed by the European Organization for Research and Treatment of Cancer/Groupe d'Etude des Lymphomes de l'Adulte, German Hodgkin Study Group, or National Comprehensive Cancer Network. TMTV and iPET2 were independently prognostic and, combined, identified 4 risk groups: low (TMTV≤147+DS1-3; 5-year PFS, 95%), low-intermediate (TMTV>147+DS1-3; 5-year PFS, 81.6%), high-intermediate (TMTV≤147+DS4-5; 5-year PFS, 50%), and high (TMTV>147+DS4-5; 5-year PFS, 25%). TMTV improves baseline risk stratification of patients with early-stage HL compared with current staging systems and the predictive value of early PET response as well.

Cancer Evolution and the Limits of Predictability in Precision Cancer Medicine

The ability to predict the future behavior of an individual cancer is crucial for precision cancer medicine. The discovery of extensive intratumor heterogeneity and ongoing clonal adaptation in human tumors substantiated the notion of cancer as an evolutionary process. Random events are inherent in evolution and tumor spatial structures hinder the efficacy of selection, which is the only deterministic evolutionary force. This review outlines how the interaction of these stochastic and deterministic processes, which have been extensively studied in evolutionary biology, limits cancer predictability and develops evolutionary strategies to improve predictions. Understanding and advancing the cancer predictability horizon is crucial to improve precision medicine outcomes.

Baseline metabolic tumour volume is an independent prognostic factor in Hodgkin lymphoma

PURPOSE

The presence of a bulky tumour at staging in Hodgkin lymphoma (HL) is a predictor of a poor outcome. The total metabolic tumour volume at baseline (TMTV0) computed on PET may improve the evaluation of tumour burden. To explore the clinical usefulness of TMTV0, we compared the prognostic value of TMTV0, tumour bulk and interim PET response in a retrospective single-centre study.

METHODS

From 2007 to 2010, 59 consecutive patients with a first diagnosis of HL were treated in our institution. PET was done at baseline (PET0) and after two cycles of chemotherapy (PET2), and treatment was not modified according to the PET2 result. TMTV0 was measured with a semiautomatic method using a 41 % SUVmax threshold. SUVmax reduction between PET0 and PET2 (ΔSUVmaxPET0-2) was also computed. Based on ROC analysis, patients with a ΔSUVmaxPET0-2 >71 % were considered good responders and a TMTV0 >225 ml was considered to represent hypermetabolic bulky disease.

RESULTS

Median TMTV0 was 117 ml and 17 patients (29 %) had a TMTV0 >225 ml. TMTV0 (>225 ml vs. ≤225 ml) and tumour bulk (<10 cm vs. ≥10 cm) were predictive of 4-year PFS: 42 % vs. 85 % (p = 0.001) and 44 % vs. 79 % (p < 0.03), respectively. In multivariate analysis, using ΔSUVmaxPET0-2, TMTV0 and bulky tumour as covariates, only ΔSUVmaxPET0-2 (p = 0.0005, RR 6.3) and TMTV0 (p < 0.006, RR 4.4) remained independent predictors of PFS. Three prognosis groups were thus identified: ΔSUVmaxPET0-2 >71 % and TMTV0 ≤225 ml (n = 37, 63 %), ΔSUVmaxPET0-2 = <71 % or TMTV0 >225 ml (n = 17, 29 %), and ΔSUVmaxPET0-2 = <71 % and TMTV0 >225 ml (n = 5, 8 %). In these three groups the 4-year PFS rates were 92 %, 49 %, and 20 % (p < 0.0001), respectively.

CONCLUSION

TMTV0 is more relevant than tumour bulk for predicting the outcome in patients with HL, and adds a significant prognostic insight to interim PET response assessment. The combination of TMTV0 and ΔSUVmaxPET0-2 made it possible to identify three subsets of HL patients with different outcomes. This may guide clinicians in their choice of therapeutic strategy.

Metabolic tumor volume by positron emission tomography/computed tomography as a clinical parameter to determine therapeutic modality for early stage Hodgkin's lymphoma

Recent studies have shown that metabolic tumor volume (MTV) by positron emission tomography/computed tomography (PET/CT) is an important prognostic parameter in patients with non-Hodgkin's lymphoma. However, it is unknown whether doxorubicin, bleomycin, vinblastine, dacarbazine (ABVD) alone in early stage Hodgkin's lymphoma would lead to similar disease control as combined modality therapy (CMT) using MTV by PET/CT. One hundred and twenty-seven patients with early stage Hodgkin's lymphoma who underwent PET/CT at diagnosis were enrolled. The MTV was delineated on PET/CT by the area ≥SUV(max), 2.5 (standardized uptake value [SUV]). Sixty-six patients received six cycles of ABVD only. The other 61 patients received CMT (involved-field radiotherapy after 4-6 cycles of ABVD). The calculated MTV cut-off value was 198 cm(3) . Clinical outcomes were compared according to several prognostic factors (i.e. age ≥50 years, male, performance status ≥2, stage II, B symptoms, ≥4 involved sites, extranodal site, large mediastinal mass, CMT, elevated erythrocyte sedimentation rate and high MTV). Older age (progression-free survival [PFS], P = 0.003; overall survival [OS], P = 0.007), B symptoms (PFS, P = 0.006; OS, P = 0.036) and high MTV (PFS, P = 0.008; OS, P = 0.007) were significant independent prognostic factors. Survival of two high MTV groups treated with ABVD only and CMT were lower than the low MTV groups (PFS, P < 0.012; OS, P < 0.045). ABVD alone was sufficient to control disease in those with low MTV status. However, survival was poor, even if the CMT was assigned a high MTV status. The MTV would be helpful for deciding the therapeutic modality in patients with early stage Hodgkin's lymphoma.

Tumour burden predicts treatment resistance in patients with early unfavourable or advanced stage Hodgkin lymphoma treated with ABVD and radiotherapy

The purpose of the work was to investigate the factors predicting early resistance to treatment in Hodgkin lymphoma. Many staging parameters, including relative tumour burden (rTB), were analysed in 246 patients with Hodgkin lymphoma in relation to early failure, that is, less than complete remission (i.e. partial response, null response or progression) or occurrence of early relapse, as clinical expressions of resistance to treatment. Patients with early unfavourable disease were 129 and were treated with four to six cycles of ABVD + involved field radiotherapy; 117 patients with advanced stage disease received six cycles of ABVD + optional irradiation to no more than two sites. The rTB was volumetrically measured through the evaluation of staging computed tomography for all the lesions except bone marrow involvement, which was quantified by calculation. The relationship with early resistance was analysed with logistic regressions. The rTB demonstrated to be the best predictor of early failure in both patient subsets, being superior to the multiparameter International Prognostic Score. The rTB showed a significant exponential relationship with the relative risk of early failure, and with inclusion of the extranodal involvement into the model, a single equation became adequate to predict resistance in both early unfavourable and advanced stage patients. The conclusions are that the rTB is the best pretreatment factor related to the risk of resistance to combined ABVD + radiotherapy and that this relationship can be mathematically expressed in an easy way. A simplified assessment of rTB is highly desirable.

Chemoresistance as a function of the pretherapy tumor burden and the chemotherapy regimen administered: differences observed with 2 current chemotherapy regimens for advanced Hodgkin lymphoma

BACKGROUND

The mature results from trials comparing ABVD (Adriamycin [doxorubicin], bleomycin, vinblastine, dacarbazine) and BEACOPP (bleomycin, etoposide, Adriamycin [doxorubicin], cyclophosphamide, Oncovin [vincristine], procarbazine, prednisone) chemotherapies in advanced Hodgkin lymphoma will be available in some years. An early comparison of their curative potential can however be obtained from an assessment of initial tumor burden and chemoresistance.

PATIENTS AND METHODS

Less than a complete remission after treatment and relapse occurring within 12 months thereafter were assumed to be clinical expressions of chemoresistance. The tumor burden was calculated from the measurements of all the lesions documented by staging computed tomography (CT) and was normalized to body surface area to give the relative tumor burden (rTB). Using logistic regression analysis, the relationship between initial rTB, chemoresistance, and chemotherapy regimen administered was retrospectively studied in 222 patients selected from those enrolled in 2 similar randomized trials.

RESULTS

The median rTB volumes were 157.9 cm(3)/m(2) in the 115 patients treated with ABVD vs. 154.6 cm(3)/m(2) in the 107 patients treated with BEACOPP, and the distribution of the volumes was identical in the 2 groups. The rTB was confirmed as the best predictor of early treatment failures (22 less than complete responses plus 21 early relapses). For the same rTB, the risk of chemoresistance to BEACOPP was about half that of the chemoresistance to ABVD or, for a given risk of chemoresistance, BEACOPP cured patients with an rTB 89.1 cm(3)/m(2) greater than that cured by ABVD (ie, more than 50% of the median tumor load of patients with advanced-stage disease).

CONCLUSION

This account of rTB allows an early comparative evaluation of the curative ability of different chemotherapy regimens.

Volume assessment accuracy in computed tomography: a phantom study

There is a broad push in the cancer imaging community to eventually replace linear tumor measurements with three‐dimensional evaluation of tumor volume. To evaluate the potential accuracy of volume measurement in tumors by CT, a gelatin phantom consisting of 55 polymethylmethacrylate (PMMA) spheres spanning diameters from 1.6 mm to 25.4 mm was fabricated and scanned using thin slice (0.625 mm) CT (GE LightSpeed 16). Nine different reconstruction combinations of field of view dimension (FOV=20,30,40 cm) and CT kernel (standard, lung, bone) were analyzed. Contiguous thin‐slice images were averaged to produce CT images with greater thicknesses (1.25, 2.50, 5.0 mm). Simple grayscale thresholding techniques were used to segment the PMMA spheres from the gelatin background, where a total of 1800 spherical volumes were evaluated across the permutations studied. The geometric simplicity of the phantom established upper limits on measurement accuracy. In general, smaller slice thickness and larger sphere diameters produced more accurate volume assessment than larger slice thickness and smaller sphere diameter. The measured volumes were smaller than the actual volumes by a common factor depending on slice thickness; overall, 0.625 mm slices produced on average 18%, 1.25 mm slices produced 22%, 2.5 mm CT slices produced 29%, and 5.0 mm slices produced 39% underestimates of volume (mm³). Field of view did not have a significant effect on volume accuracy. Reconstruction algorithm significantly affected volume accuracy (p<0.0001), with the lung kernel having the smallest error, followed by the bone and standard kernels. The results of this investigation provide guidance for CT protocol development and may guide the development of more advanced techniques to promote quantitatively accurate CT volumetric analysis of tumors.

PACS number: 87.57.Q‐

Symptom Burden: A Concept Analysis and Implications for Oncology Nurses

PURPOSE/OBJECTIVES

To analyze the concept of symptom burden and discuss implications for symptom research and symptom management.

DATA SOURCES

MEDLINE, CINAHL, PsycINFO, Cochrane Reviews, and published literature.

DATA SYNTHESIS

Through Rodgers's evolutionary method of concept analysis, attributes of symptom burden were identified as dynamic, multidimensional, quantifiable, subjective, and physiologic. The major antecedent was multiple symptoms related to worsening disease status. Consequences of symptom burden included decreased survival, poor prognosis, delay or termination of treatment, increased hospitalizations and medical costs, decreased functional status, and lowered self-reported quality of life. Symptom burden is defined as the subjective, quantifiable prevalence, frequency, and severity of symptoms placing a physiologic burden on patients and producing multiple negative, physical, and emotional patient responses.

CONCLUSIONS

Symptom burden is an important concept in the symptoms experience, separate from symptom distress and other related terms. The continued differentiation of symptom concepts is important for sound methodologic research and meaningful interventions that affect and improve patient experiences.

IMPLICATIONS FOR NURSING

Clarifying multiple symptom concepts in the symptoms experience, determining appropriate measurement methodologies for the concepts, and identifying appropriate strategies will lessen the burden of symptoms and contribute to improved quality of life and better patient outcomes.

Very high levels of soluble CD30 recognize the patients with classical Hodgkin's lymphoma retaining a very poor prognosis

OBJECTIVES

To evaluate the prognostic role of pretreatment serum levels of soluble CD30 (sCD30) in patients with advanced stage classical Hodgkin's lymphoma (cHL) treated with adriamycin, bleomycin, vinblastine, and dacarbazine or equivalent regimens.

METHODS

We identified 321 previously untreated patients with cHL who presented to the participating centers between 1985 and 2002, and had serum samples available for the determination of sCD30 levels.

RESULTS

With a median follow-up of 72 months, the actuarial 5-year overall survival was 82%, and failure-free survival (FFS) was 71%. The median serum level of sCD30 was 65 U/mL (range: 1-2230), and was significantly higher (P < 0.0001) when compared with a group of 113 healthy controls (4 U/mL, range: 0-20). Increasing level of sCD30 was associated with a continuous worsening of FFS and OS, and patients with sCD30 >or=200 U/mL had a 5-year FFS of 39%. With multivariate analysis, sCD30, Ann Arbor stage, and lactic acid dehydrogenase were significant independent factors in terms of FFS. The association of the above-mentioned three independent prognostic variables could discriminate 22% of patients with 5-year FFS of 40%.

CONCLUSIONS

Our data confirm the independent prognostic role of sCD30 in identifying the patients with high risk of treatment failure, and show that its association with other variables can recognize patients with FFS considerably lower than 50%.

Hodgkin's disease

A direct method for the evaluation by computed tomography (CT) of the neoplastic mass (tumor burden [TB]) has been adopted in 34 patients diagnosed with Hodgkin's disease in the early stage. Stressed are its prognostic value, and its correlation with the clinical and laboratory parameters usually adopted in the staging of the disease and in its follow-up. It is concluded that the CT-calculated TB is a reliable index showing good correlation with other commonly used prognostic parameters.

Does bulky disease at diagnosis influence outcome in childhood Hodgkin's disease and require higher radiation doses? Results from the German-Austrian Pediatric Multicenter Trial DAL-HD-90

PURPOSE

The identification of risk factors is required for risk-adapted treatment strategies in the treatment of Hodgkin's disease. To assess the influence of bulky disease at diagnosis as compared with other risk factors on event-free survival (EFS) in pediatric Hodgkin's disease such as stage, B-symptoms, number of involved lymph node regions, histology, and remission status after chemotherapy, we analyzed the outcome of 552 patients treated with a risk-adapted treatment strategy consisting of OPPA(OEPA)/COPP (vincristine, procarbazine, etoposide, prednisone, adriamycin, cyclophosphamide) and involved-field radiotherapy.

METHODS AND MATERIALS

Between 1990 and 1995, 578 patients with primary Hodgkin's disease (HD) were enrolled in the German/Austrian Pediatric Hodgkin's Disease Study Group (DAL) Multicenter Study (HD-90). Patients were stratified into three treatment groups (TGs) for early, intermediate, and advanced stage. All patients received induction chemotherapy (CT) with two cycles of OEPA for boys and two cycles of OPPA for girls. Patients in TG2 and TG3 received another two or four cycles, respectively, of COPP. Chemotherapy was followed by involved-field radiotherapy. The radiation field, which was prescribed by the study center, was treated with a dose of 25 Gy/25 Gy/20 Gy (TG1/TG2/TG3), and in case of insufficient remission with a local boost of 5 Gy to 10 Gy. The following prognostic factors were analyzed with regard to their impact on EFS: bulky disease, mediastinal tumor, number of involved lymph node regions, histology, treatment group, B-symptoms, sex, age, and remission status after chemotherapy.

RESULTS

Significant univariate predictive factors for the EES were: nodular sclerosis type 2 (NS2) histology (relative risk [RR] 3.43; p = 0.0002), presence of B-symptoms (RR 2.70; p = 0.0014), number of involved regions (1.55; p = 0.019), and treatment groups (RR 1.33; p = 0.017). There was a higher risk (RR 1.92; p = 0.040) for patients with bulky compared with nonbulky disease (5-year EFS 89.6%/94.6%). In the multiple regression model, only NS2 and B-symptoms remained strong predictive factors. The remission status after chemotherapy did not correlate with EFS (p = 0.66).

CONCLUSION

Treatment strategies in Hodgkin's disease have an impact on different risk factors. In the risk-adapted treatment strategy of the HD-90 study, tumor burden indicated as bulky disease or as number of involved lymph nodes loses its importance, whereas NS2 histology and B-symptoms have a major impact on treatment outcome. Bulky disease at diagnosis might require higher radiation doses only in case of insufficient remission.

The disappearance of prognostic factors in Hodgkin's disease

The purpose of this conceptual (and somewhat provocative) article is to analyse the reasons for the disappearance of prognostic factors in Hodgkin's disease (HD) and to explore the consequences for further research from a biometrical point of view. The very concept of prognostic factors is about to resolve in HD. Prognostic factors gradually loose their predictive power as treatment is successfully adapted to the disease burden. Freedom from treatment failure and overall survival curves of patients in early, intermediate and advanced stages of HD are superimposable with the best current treatment protocols of the German Hodgkin's Lymphoma Study Group. This disappearance of prognostic factors in HD necessitates a certain conceptual remodelling. It's time to think quantitatively and bivariately, and we need to (i) synthesise existing 'prognostic' factors into a quantitative measure of disease burden or severity; (ii) develop a quantitative measure of treatment strength and (iii) relate these two quantities in nomogram curves indicating how much treatment a patient with a given disease burden requires to have, say, a 85%, 90% and perhaps 95% expected chance of cure.

Early response to chemotherapy: a surrogate for final outcome of Hodgkin's disease patients that should influence initial treatment length and intensity?

BACKGROUND

Early adjustment of treatment may benefit the patient. In order to guide treatment adjustment, use of early response (ER) or early complete response (ECR), judged after the few initial cycles of chemotherapy, is common in pediatric and also adult Hodgkin's and non-Hodgkin's studies. Paradoxically, almost no data support this strategy.

PATIENTS AND METHODS

The influence of ECR on outcome was evaluated in three series of advanced Hodgkin's disease (HD), leading to a series of questions.

RESULTS

The 1982 EORTC study assessed prospectively the time frame needed to reach an apparent complete response (CR) through repeated tumor measurements. In patients assessed at mid-treatment before the fifth cycle, both 15 year freedom from progression (FFP) and overall survival (OS) were superior in ECR patients compared with other patients continued on the same treatment (61% versus 37%; P < 0.001). A series of questions arise from these observations. Question 1: is the shortening of treatment detrimental? In a randomized Swedish trial, in one arm treatment was shortened in patients evaluated from the fifth cycle as ECR as compared with the standard eight cycles arm, 10 year cause-specific-survival (CSS) was 53 versus 69% [not significant (ns)]; 10 year OS 49% versus 58% (ns). Conversely, in the EORTC 20884 study, ECR patients given only six cycles did as well as patients entering CR later and, for this reason, given eight cycles (identical 6 year event-free survival 75%). Question 2: is early treatment adaptation in patients who failed to reach ER beneficial? In the French MDH 90 trial, 15% of children failed to reach ECR after four cycles; in these children only, anthracyclines plus alkylating agents were given and the dose of radiotherapy increased, improving the results observed in the previous trial. In the EORTC 20884 study, patients who failed to reach an ECR were switched earlier to involved field RT: their results matched those of ECR patients, at the difference of the previous trial. Question 3: is ER a predicting factor that can be used with any type of treatment? Probably not, based on the German Hodgkin's Lymphoma Study Group trial HD 9: ECR is highly dependent on specific interval from treatment start and on treatment intensity.

DISCUSSION

More general questions stem from these results. Question 4: is the definition of ER secured? With conventional imaging, the different methods for response assessment at end treatment also lead to different response rates; the assessment in the middle of treatment itself and the use of newer imaging techniques may further increase the variation. Indeed, question 5 is: is ER a concept based on any biology? Correlation to markers, 99mTc uptake, PET and hematological tolerance might help to pinpoint how and why ER represents a surrogate for final outcome.

CONCLUSION

ER is a surrogate for final outcome, reflecting both tumor burden and activity. This predictability may, and possibly should, impact on treatment.

Prognostic factors in Hodgkin's lymphoma

Risk-adapted treatment strategies have constituted a major issue since the beginning of clinical research into Hodgkin's disease (HD). Various prognostic factors have been identified and several of those considered for staging procedures, resulting in strictly stage-dependent treatment recommendations for patients suffering from HD. These factors may be subdivided in host-related (e.g. age, sex) and tumour-related (e.g. number of tumour cells, growth characteristics, spread of tumour cells, resistance to apoptosis) factors. Owing to the striking improvement of the overall prognosis in HD patients it may be difficult to identify novel prognostic factors analysing the minority of patients with a fatal outcome. However, especially in advanced-stage disease, improved treatment results were achieved by the introduction of more aggressive treatment regimens, resulting in an increased toxicity rate. Thus, partially in contrast to earlier work in this field, future prognostic factors are needed for identification of those patients that have a good prognosis and might be susceptible to overtreatment. During the Fifth International Symposium on Hodgkin's Lymphoma, promising results on several new prognostic markers were presented. Furthermore, a joint effort to design new studies on large, well characterised patient groups has been initiated.

Prognostic factors in advanced stage Hodgkin's lymphoma: the significance of the number of involved anatomic sites

BACKGROUND

Advanced Hodgkin's lymphoma (HL) is curable by conventional chemotherapy in 60--70% of patients. The pretreatment identification of a sizeable subgroup of patients with sufficiently low failure-free survival (FFS) to be eligible for investigational treatment is necessary.

OBJECTIVES

To determine the prognostic significance of the number of involved sites (NIS) in patients with advanced HL and its relationship to the International Prognostic Score (IPS).

METHODS

A retrospective review of patients with advanced HL, defined as Ann Arbor stage (AAS) IB, IIB, III or IV, treated with anthracycline-based regimens. The end-point was FFS.

RESULTS

We identified 277 patients with a median age of 32 yr (14--78), 57% of whom were males. AAS was I in 4% of patients, II in 29%, III in 38% and IV in 29%. B-symptoms were recorded in 81%. Most patients had nodular sclerosis (64%) and mixed cellularity (26%) histology. IPS was greater-than-or-equals 3 in 44% of 242 evaluable patients. The NIS was greater-than-or-equals 5 in 32% of the patients and 20% of all patients had both greater-than-or-equals 5 involved sites and IPS greater-than-or-equals 3. The 10-yr FFS was 67%, being 76% vs. 50% for patients with less-than-or-equals 4 vs. greater-than-or-equals 5 involved sites (P < 0.0001). The NIS (greater-than-or-equal 5), AAS IV and anemia were independent predictors of FFS in multivariate analysis. The NIS remained significant along with IPS, when the latter was included in the analysis. Patients with greater-than-or-equals 5 involved sites and IPS greater-than-or-equals 3 had 10-yr FFS overall, and relapse-free survival of 41%, 45% and 49%, respectively.

CONCLUSIONS

The NIS was associated with FFS in advanced HL, was independent of IPS, and led to the identification of a sizeable subgroup of patients with 10-yr FFS of approximately 40%. This factor should be evaluated during the development of prognostic systems.