Alliance A032002 (ART): Phase II randomized trial of atezolizumab versus atezolizumab and radiation therapy for platinum-ineligible/refractory metastatic urothelial cancer

TPS589

Background: In patients (pts) with metastatic unresectable urothelial cancer, platinum-based chemotherapy remains the standard of care for first-line treatment followed by switch maintenance avelumab if disease control is achieved with chemotherapy. Outside of this setting, single agent immunotherapy is often used in pts that have recurrence after platinum-based chemotherapy or are platinum ineligible. Atezolizumab is a PD-L1 inhibitor currently approved for pts that have urothelial cancers expressing positive PD-L1 or pts ineligible for receiving platinum-based chemotherapy. Tumor-targeted radiotherapy can generate immune-stimulating effects without immune suppression as was previously thought. Moreover, it has become clear that radiotherapy can induce profound effects on tumor cells and the tumor microenvironment that can enhance or trigger an anticancer immune response. While numerous trials have investigated the abscopal effect, this trial will have specific parameters regarding drug type, radiation dose and administration. Methods: A032002 is a phase 2 trial addressing pts that are platinum ineligible or refractory to platinum-based chemotherapy. 144 pts will be randomized to receive either atezolizumab or atezolizumab and single site radiation therapy. The atezolizumab regimen is 1200 mg every 3 weeks. Administration of radiotherapy will occur to one non-target site (8 Gy x 3) for pts randomized to the atezolizumab + radiotherapy arm. All pts will undergo centralized PD-L1 testing (SP142 monoclonal primary antibody), which can be performed on archival tissue; a new biopsy is only required if no archival tissue is available. Key eligibility criteria include age ≥ 18 years, ECOG performance status 0-2, histologically confirmed metastatic urothelial cancer, having at least one measurable site per RECIST 1.1 to monitor for abscopal response, one site targetable for radiation, and tissue available for PD-L1 testing. The primary endpoint is tumor response within 6 months of randomization. Tumor response is defined as a complete response (CR) or partial response (PR) as assessed by the treating physician using RECIST 1.1 criteria. For a one-sided log rank test with a type 1 error rateof 0.10, the study has 90% power to detect a 20% increase in response rate. Key secondary endpoints include tumor response using iRECIST, progression-free survival and overall survival. Quality of life assessments include EORTC QLQ-C30, QLQ-BLM30 and PROMIS-Fatigue. Tissue, urine and blood samples will be collected and biobanked for future correlative science. Enrollment to ART began in December 2021. The study is available for participation at all US NCTN sites with a projected enrollment of 3 years. Support: U10CA180821, U10CA180882. Clinical trial information: NCT04936230 .

Association of early tumor growth rate and survival outcomes in first-line metastatic non–small cell lung cancer (mNSCLC)

9063

Background: Tumor growth rates ( g) estimated using imaging measurements, have been associated with overall survival (OS) and progression-free survival (PFS) in patients with mNSCLC, including those treated with first-line immunotherapy (1L IO) or chemotherapy (chemo). Here, we evaluated whether early g estimates within 18 weeks of first treatment dose are associated with survival outcomes for 1L treatment in mNSCLC. Methods: This was a retrospective analysis of data from patients randomized to either nivolumab+ipilimumab (NIVO+IPI) or chemo in CheckMate 227 Part 1 (NCT02477826), or NIVO+IPI+chemo or chemo alone in CheckMate 9LA (NCT03215706). Tumor assessments were performed by blinded independent central review using RECIST v 1.1 at baseline, every 6 weeks for the first 48 weeks and then every 12 weeks until disease progression. The analysis included patients with at least 3 measurable timepoints, including baseline, week 6, week 12, and/or week 18. If a patient did not have a week 18 measurement, the first three measurements alone were used. To derive the median early g, sum of longest diameters (SLD), based on baseline, weeks 6, 12 and/or 18 assessments, and time relative to baseline were fitted to the model defined by sum of exponential growth (g) and decay (d): SLD (t) = exp (–d x t) + exp (g x t) – 1. OS and PFS were estimated using Kaplan-Meier methodology. Results: In the two studies, 865/1166 (75%) of randomized patients in CheckMate 227 Part 1 and 562/719 (78%) in CheckMate 9LA had evaluable tumor growth rate data (Table). The median early g at weeks 12 and 18 was numerically lower for the IO-containing arm vs chemo arm in both studies (Table). Patients with lower growth rate at week 12 or week 18 ( g in first quartile [Q1]) had better OS relative to those with higher rate ( g in fourth quartile [Q4]) across all treatment arms (Table). A similar trend was observed for PFS. Conclusions: Early g estimates based on 2 or 3 post-baseline tumor assessment timepoints were associated with longer-term survival outcomes for 1L treatment of mNSCLC and could discern efficacy outcomes. These findings provide the foundation for further research, which may incorporate volumetric segmentations of measurable lesions and radiomic feature changes to further explore indicators of patient outcomes that could inform future clinical trials and clinical practice.[Table: see text]

Radiomic signatures to predict survival in patients with advanced hepatocellular carcinoma (HCC) treated with sorafenib +/- doxorubicin: Correlative science from CALGB 80802 (Alliance)

343

Background: Alliance/CALGB 80802, a randomized phase III trial, evaluated sorafenib plus doxorubicin vs. doxorubicin in pts with HCC and showed no improvement in median overall survival (OS) (HR[95CI] 1.05[0.83-1.31]) or PFS (HR[95CI] 0.93[0.75-1.16]). In HCC surrogacy of tumor response with OS remains controversial, in part due to varying criteria used for response evaluation (e.g., RECIST1.1 and mRECIST). We evaluated the performance of several models to predict OS using pretreatment clinical and radiomic variables. Methods: In CALBG 80802, we segmented all measurable tumor lesions on sequential CT scans. A lesion’s imaging phenotype was deciphered with 23 uncorrelated quantitative imaging features measured at baseline and week (wk) 10 (first follow-up). An OS landmark survival analysis was conducted at wk 10. Patients were randomly assigned (3:1) to training (n = 92) and validation (n = 37) sets. In a training set, 6 random forest predictive models (6 signatures) used features that best predicted OS using 3 sets of variables: radiomics only (n = 23), clinical only (n = 9), radiomics and clinical (n = 32). Two time points (baseline only or baseline + wk 10) were assessed. Each signature's output was an individualized prediction and a continuous value ranging from 0 to 1 (from most to least favorable predicted OS). The primary endpoint was to compare these models' performance to predict OS using error rate (Harrell's concordance-index) in the validation set. Results: Of the 6 training signatures evaluated, the one achieving the highest performance in the validation set was an 8-feature signature combining radiomics and clinical variables measured at two time points (baseline + wk 10) with an error rate of 35.6%. The variables [rank of importance] (table) selected by the signature included baseline clinical features (albumin[1], AFP[2], Child-Pugh[4]), baseline radiomics features (component 17[3], component 1[5], component 9[7], tumor volume[8]) and wk 10 radiomics features (delta tumor volume[6]). Variable delta tumor volume [6] used a more enhanced estimation of tumor burden at baseline and a delta tumor volumetric measurement; compared to RECIST1.1 measurement of percentage change in unidimensional measurement of a subset of target lesions. The four quartiles of the signature were significantly associated with OS (Log-Rank, P < 0.0001). Conclusions: The selected combined radiomic and clinical composite signature provided the best prediction for OS in the 80802 study patients’ population. It is a suggested way forward to go beyond single anatomic measurement techniques such as RECIST or mRECIST. [Table: see text]

Alliance/CALGB 80802: Impact of hepatitis C (HCV) on doxorubicin (DO) + sorafenib (S) versus S in patients (pts) with advanced hepatocellular carcinoma (aHCC)

325

Background: Alliance/CALGB 80802 randomized phase III trial evaluated DO+S vs. S in pts with aHCC, and showed no improvement in median OS. Multi-drug resistant pathway mitigation by the Ras/Raf/MEK/ERK pathway and bFGF-mediated activation of Raf-1 promotes the formation of antiapoptotic Raf-1 and ASK1 complex, induced by anthracyclines. S efficiently blocks NS5A-recruited c-Raf mediated HCV replication and viral gene expression. Once inhibited by S, VEGF expression of HepG2 may limit HCV cellular entry. Release of Raf-1-Ask-1 dimer and inhibition of Raf-1 via S putatively differ in the presence or absence of DO. We hypothesize treatment with S reduces HCV titer levels (TL) and influence pts’ outcome. Methods: In 80802 HCV pts, TL were evaluated in both arms at baseline and post-baseline at Day 1 of Cycles 2, 3, and every 2 cycles and at progression or discontinuation of therapy. HCV undetectable (HCV-UN) levels were defined as < 50 copies/mL. TL were evaluated in relation to OS and PFS. HCV RNA levels were measured by TaqMan PCR and by genotype. Results: Of 356 pts, 83 were HCV+ with more Black/African American (25/50 = 50%) vs. White (54/239 = 23%) or other race groups (4/67 = 6%) (p < 0.0001). HCV titer data were available on 54 pts (S: 28, DO+S: 26). At baseline, 12 pts (S: 7, DO+S: 5) were HCV-UN, and post-baseline HCV TL did not significantly differ between treatment arms; one patient in each arm went from detectable (HCV-D) to HCV-UN. Post-baseline, 40 pts were HCV-D vs. 14 who were HCV-UN (S+DO: 8, S: 6 pts). Except for the two pts who became HCV-UN, baseline HCV-D vs. HCV-UN titers was similar to that status post-baseline. PFS and OS between HCV-D and HCV-UN both at baseline and post-baseline are delineated in the table. Conclusions: We observed that S did not influence HCV TL. Pts treated with DO+S vs. S had worse PFS if they had HCV-UN, and further that higher levels of HCV titers at baseline were associated with significantly improved PFS. Given the small sample size, these findings warrant further prospective evaluation. Support: U10CA180821, U10CA180882, U24CA196171; Bayer, Bristol-Myers-Squibb, and Sanofi. https://acknowledgments.alliancefound.org . Clinical trial information: NCT01015833. [Table: see text]

Discordance between central versus local response assessments in neuroendocrine tumor (NET) patients (pts) enrolled in A021202

361

Background: Assessment of tumor response in extrapancreatic NETs with metastases can be very challenging. Previous studies suggest a high degree of discordance between local and central imaging reviews, which has implications for clinical practice and trial design. Methods: Serial images archived from a randomized phase II trial (A021202) of pazopanib vs placebo in progressive non-pancreatic NETs were evaluated by central review, with real-time review conducted at the time of locally interpreted progressive disease (PD). The primary endpoint of the trial was progression-free survival (PFS) by central review. Discordances between central (Alliance Imaging Core Laboratory) and local (investigator-reported) reviews were assessed. Scan-level and pt-level results across both treatment arms were evaluated. Kappa tests were used to test concordance based on source of review. Results: 151 pts had a total of 724 scans with response adjudication by both local and central RECIST review. Discordance was observed in both directions. Overall, 20% of scans (143/724) had discordant classifications. The most common discordances were: stable disease (SD) on local vs. PD on central review (82/143=57%), and PD on local vs. SD on central review (32/143=22%). On a pt level, 78 of 151 pts (52%) had discordant reviews; 8 had >1 type of discordance. Overall, 30% of pts (N=45) had a determination of PD on central review, but SD or better on local review, potentially resulting in excessive exposure to therapy. In contrast, 20% (N=30) were classified as PD on local read but SD or better on real-time central review (which did not necessarily translate into an abbreviated course of treatment). Cohen’s kappa statistics revealed only moderate concordance between local and central reviewers both at the scan (K=0.48, 95% CI: 0.42 – 0.55) and pt (K=0.41, 95% CI: 0.32 – 0.5) levels, with no significant influence by treatment arm, primary tumor site, tumor functionality, histology, differentiation or primary disease spread. Conclusions: Discordance was observed in both directions, where 30% of pts were potentially kept on study drug too long (based on central read), and 20% would have been taken off study treatment early for local PD were it not for real-time central review. Although this bidirectional discordance did not affect the overall findings of the PFS outcome between arms in the trial, these analyses highlight the high prevalence of discordance, the potential to negatively influence treatment duration in both directions, and the need for more straightforward methods of assessing treatment response in carcinoid. Support: U10CA180821, U10CA180882, U24CA196171; NETRF Investigator Award; https://acknowledgments.alliancefound.org Clinical trial information: NCT01841736.

POLO: Radiologic assessment of the impact of maintenance olaparib in patients (pts) with metastatic pancreatic cancer (mPaC)

412

Background: The phase III POLO study (NCT02184195) demonstrated a benefit of maintenance olaparib over placebo in the radiologically assessed primary endpoint of progression-free survival (PFS) in pts with mPaC (median 7.4 vs 3.8 months [mo]; 12-mo rate 34% vs 15%). The impact of radiologic assessment of pancreatic lesions, which is considered challenging, was explored. Methods: Tumors were assessed using Response Evaluation Criteria in Solid Tumors version 1.1 by blinded independent central review (BICR) in pts with mPaC treated with maintenance olaparib or placebo. PFS was analyzed in subsets of pts based on various event criteria. Results: All 154 randomized pts had mPaC prior to chemotherapy, of whom 122 had disease in the pancreas at POLO baseline (BL); 34% (53/154) had pancreas-only target lesions (TL), 26% (40/154) also had ≥1 TL outside of the pancreas, and in 19% (29/154) pancreatic disease was recorded as non-TL. Sensitivity analyses were consistent with the primary PFS analysis (Table), including when all pancreas lesion assessments were discounted (median PFS 7.4 vs 4.7 mo; 12-mo rate 38% vs 22%). Of 53 pts with pancreas-only TLs at BL, 34 had disease progression (PD); in 20 pts this was not solely based on TL measurements (16 had new lesions; 4 had multiple-cause PD). Confirmed objective responses occurred during study maintenance treatment in 20% of olaparib pts (18/92) and 10% of placebo pts (6/62). In pts with pancreas-only TLs at BL there were 7 responses in the olaparib arm (1 complete response [CR], 6 partial responses [PR]) and 2 (2 PR) in the placebo arm. In pts who had ≥1 TL outside of the pancreas at BL there were 11 (1 CR, 10 PR) and 4 (4 PR) responses, respectively. Responses were generally durable irrespective of TL location. Conclusions: The significant PFS benefit with maintenance olaparib over placebo shown in the primary analysis was consistent across all sensitivity analyses and was not impacted by radiologic assessment of pancreatic TLs. Taken together, these findings suggest that contrary to historically held belief, primary pancreas TLs may be appropriate for inclusion as sites of RECIST-evaluable disease and for assessment of treatment outcome. Clinical trial information: NCT02184195. [Table: see text]

Alliance A021501: Preoperative mFOLFIRINOX or mFOLFIRINOX plus hypofractionated radiation therapy (RT) for borderline resectable (BR) adenocarcinoma of the pancreas

377

Background: Neoadjuvant therapy has been associated with a median overall survival (OS) of 18 – 23 months (mo) in patients (pts) with BR pancreatic ductal adenocarcinoma (PDAC). To establish reference regimens to which novel treatments can be compared in future studies, we evaluated neoadjuvant mFOLFIRINOX with or without RT in BR PDAC in a phase II National Clinical Trials Network (NCTN) trial. Methods: Pts with ECOG PS 0-1 and BR PDAC confirmed by central real-time radiographic review after pre-registration were randomized to either arm A: 8 cycles of neoadjuvant mFOLFIRINOX (oxaliplatin 85 mg/m2, irinotecan 180 mg/m2, leucovorin 400 mg/m2 and infusional 5-fluorouracil 2400 mg/m2 over 46 hours), or arm B: 7 cycles of mFOLFIRINOX followed by stereotactic body RT (SBRT, 33-40 Gy in 5 fractions [fx]) or hypofractionated image guided RT (HIGRT, 25 Gy in 5 fx). Pts in either arm without disease progression underwent pancreatectomy, then 4 cycles of adjuvant mFOLFOX6 (oxaliplatin 85 mg/m2, leucovorin 400 mg/m2 and infusional 5-fluorouracil 2400 mg/m2 over 46 hours). The primary endpoint, 18-mo OS rate, of each arm was compared to a historical control of 50%. Planned interim analysis mandated closure of either arm in which <11 of first 30 accrued pts underwent R0 resection. Results: 155 pts pre-registered and 126 pts were enrolled to arm A (N=70; 54 randomized, 16 following closure of arm B) or arm B (N=56; closed at interim analysis, all pts randomized prior to closure). Median age (A: 63y, B: 67y), median CA 19-9 level (A: 171 U/ml, B: 248 U/ml) and ECOG PS (A: 51% PS 0, B: 57% PS 0) of registered pts were similar between arms (p > 0.05). Treatment detailed in Table. The 18-mo OS rate based on Kaplan Meier estimates was 67.9% (95%CI: 54.6 – 78.0) in arm A and 47.3% (95%CI: 33.7 – 59.7) in arm B. Among pts who underwent pancreatectomy, 18-mo OS rate was 93.1% (95%CI: 84.3 – 100) and 78.9% (95%CI: 62.6 – 99.6) in arm A and B, respectively. With median follow-up of 27 and 31 mo, median OS was 31.0 (95%CI: 22.2 – NE) mo and 17.1 (95%CI: 12.8 – 24.4) mo in arm A and B, respectively. Conclusions: Neoadjuvant mFOLFIRINOX was associated with favorable OS relative to historical data in pts with BL PDAC in this phase II NCTN trial. mFOLFIRINOX with hypofractionated RT did not improve OS compared to historical data. mFOLFIRINOX represents a reference regimen in this setting and a backbone on which to add novel agents. Support: U10CA180821, U10CA180882, U24CA196171; https://acknowledgments.alliancefound.org Clinical trial information: NCT02839343. [Table: see text]

Eye Tracking for Deep Learning Segmentation Using Convolutional Neural Networks

Deep learning with convolutional neural networks (CNNs) has experienced tremendous growth in multiple healthcare applications and has been shown to have high accuracy in semantic segmentation of medical (e.g., radiology and pathology) images. However, a key barrier in the required training of CNNs is obtaining large-scale and precisely annotated imaging data. We sought to address the lack of annotated data with eye tracking technology. As a proof of principle, our hypothesis was that segmentation masks generated with the help of eye tracking (ET) would be very similar to those rendered by hand annotation (HA). Additionally, our goal was to show that a CNN trained on ET masks would be equivalent to one trained on HA masks, the latter being the current standard approach. Step 1: Screen captures of 19 publicly available radiologic images of assorted structures within various modalities were analyzed. ET and HA masks for all regions of interest (ROIs) were generated from these image datasets. Step 2: Utilizing a similar approach, ET and HA masks for 356 publicly available T1-weighted postcontrast meningioma images were generated. Three hundred six of these image + mask pairs were used to train a CNN with U-net-based architecture. The remaining 50 images were used as the independent test set. Step 1: ET and HA masks for the nonneurological images had an average Dice similarity coefficient (DSC) of 0.86 between each other. Step 2: Meningioma ET and HA masks had an average DSC of 0.85 between each other. After separate training using both approaches, the ET approach performed virtually identically to HA on the test set of 50 images. The former had an area under the curve (AUC) of 0.88, while the latter had AUC of 0.87. ET and HA predictions had trimmed mean DSCs compared to the original HA maps of 0.73 and 0.74, respectively. These trimmed DSCs between ET and HA were found to be statistically equivalent with a p value of 0.015. We have demonstrated that ET can create segmentation masks suitable for deep learning semantic segmentation. Future work will integrate ET to produce masks in a faster, more natural manner that distracts less from typical radiology clinical workflow.

Lung-MAP (SWOG S1400): Design, implementation, and lessons learned from a biomarker-driven master protocol (BDMP) for previously-treated squamous lung cancer (sqNSCLC)

9576

Background: S1400, a BDMP, was designed to address an unmet need in sqNSCLC, run within the National Clinical Trials Network of the National Cancer Institute using a public-private partnership (PPP). The goal of was to establish an infrastructure for biomarker-screening and rapid evaluation of targeted therapies in biomarker-defined groups leading to regulatory approval. Methods: S1400 included a screening part using the FoundationOne assay and a clinical trial part with biomarker-driven studies (BDS) and “non-match” studies (NMS) for patients not eligible for any BDS. Patients could be screened (SaP) at progression or pre-screened (PreS). Results: Between June 2014 and January 2019, 1864 patients enrolled (711 PreS, 1079 SaP), 1674 with biomarker results, and 653 registered to a study with 217 to BDS and 436 to NMS. Six BDS and 3 NMS were initiated in small subsets with all BDS and 2 NMS completed within 2-3 years (see Table). Completed BDS have not demonstrated activity with 0-2 responses. On S1400I, Nivolumab and ipilimumab did not improve survival. Response with durvalumab (S1400A) was 16%. Conclusions: Lung-MAP met its goal to quickly answer targeted and other novel therapy questions in rare sqNSCLC subpopulations, answering questions that likely would not have been otherwise feasible, thereby demonstrating value. Activated just prior to the success of PD-(L)1 therapies in sqNSCLC, the trial had to undergo major design changes. Lessons learned include the need to update based on new science and that the PPP collaboration was essential to success. Lung-MAP continues now with new BDS and NMS in all NSCLC as of January 2019. Clinical trial information: NCT02154490 . [Table: see text]

Response criteria for intratumoral immunotherapy in solid tumors: ItRECIST

3141

Background: The approval of intratumoral (IT) immunotherapy for metastatic melanoma and the active development of numerous novel IT drugs have created a need for standardized evaluation of response to this unique treatment strategy. The Response Evaluation Criteria in Solid Tumors (RECIST) is not suitable for assessing responses separately for injected and noninjected tumors. Building on RECIST concepts, we propose an IT immunotherapy RECIST (itRECIST) to capture data and assess local and systemic responses in a standardized fashion for clinical trials involving IT immunotherapies. Methods: itRECIST will address the unique needs of IT immunotherapy trials but, where possible, aligns with RECIST 1.1 and iRECIST. It does not dictate which lesions to inject but provides guidelines for collecting data and assessing response as treatment evolves. Results: itRECIST enables overall response assessment, separate response assessments in injected and noninjected lesions, and continued assessment following modifications of therapy at initial progression. At baseline, lesions are classified into 4 categories: target injected, target noninjected, nontarget injected, and nontarget noninjected. After baseline, lesions can be reclassified from noninjected to injected if the investigator decides to change the lesions to inject, but target and nontarget designations never change. Overall response at each assessment is based on target lesion response (injected and noninjected), nontarget lesion response, and absence/appearance of new lesions. Noninjected lesion response is determined by comparing tumor burden with baseline and nadir values. Injected lesion assessment is based on visit-to-visit changes in the lesions injected during treatment and on a combined assessment once the patient is off treatment. A new response category is defined to capture progression that would be “confirmed” per iRECIST even though injected lesions are responding and therapy continues. Multiple examples have been created to aid in training and adoption. Conclusions: itRECIST is an important step toward a standardized method of response assessment for this promising and evolving therapeutic modality. The proposed guidelines can be adopted into trial protocols and routine clinical practice without the need for complex additional assessments by treating physicians. Until there is evidence to support wider use, itRECIST is intended only to support standardized collection of data and to facilitate exploratory analysis. Authors G.V.G. and A.D.K. contributed equally to this work.

SWOG S1400F (NCT03373760): A phase II study of durvalumab plus tremelimumab for previously treated patients with acquired resistance to PD-1 checkpoint inhibitor therapy and stage IV squamous cell lung cancer (Lung-MAP Sub-study)

9623

Background: The Lung Cancer Master Protocol (Lung-MAP) is designed to evaluate novel targeted therapies in patients with advanced squamous lung carcinoma. In the S1400F sub-study (non-match), we tested whether combined CTLA-4 and PD-1 inhibition with durvalumab plus tremelimumab (D+T) could overcome primary or acquired resistance to anti-PD-(L)1 therapy. Response, progression-free (PFS) and overall survival, and safety in the acquired resistance cohort are reported herein. Methods: Patients with previously treated squamous lung carcinoma, performance status (PS) 0-1, and adequate organ function that developed disease progression after ≥24 weeks of anti-PD-(L)1 monotherapy were eligible. Prior severe immune-related toxicities, intervening systemic therapy and combination chemo-immunotherapy were not permitted. Patients received D1500 mg + T75 mg IV q28 days for 4 cycles then D maintenance until disease progression. The primary endpoint was best objective response (RECIST 1.1). Interim analysis for futility was planned after 20 patients evaluable for response were enrolled. If no responses were observed, the cohort would stop enrolment. Results: 30 eligible patients were accrued to the acquired resistance cohort. Median age was 68 years, 60% of patients were male, 33% PS 0 and had received a median of 2 prior lines of therapy (maximum 4). Best response to prior anti-PD-(L)1 therapy was CR/PR/SD in 3/7/20 patients, with a median duration of anti-PD-(L)1 therapy of 8.6 months (5.2-30.4). No objective responses were seen with D+T; 47% had SD as best response. Median PFS was 2.0 months (95% CI 1.6-2.9) and survival 7.5 months (95% CI 5.3-8.7). Among the 14 patients with SD as best response, the median PFS calculated from first disease assessment is 2.8 months (95% CI: 1.4-3.9). Grade≥3 adverse events at least possibly related to protocol therapy were seen in 10/30 patients. These include 1 treatment-related death due to pneumonitis and 1 death not otherwise specified. Other adverse events include grade 3 confusion (1), dehydration (2), diarrhea (3), encephalopathy (1), weakness (1), hyperglycemia (1), hypoxia (1), lymphopenia (1), nausea, (1), neutropenia (1), thrombocytopenia (1), rash (1), vomiting (1), grade 4 dyspnea (1), leucopenia (1) and lymphopenia (1). Conclusions: D+T did not demonstrate activity in patients with acquired resistance to PD-1 checkpoint inhibitors and pretreated advanced squamous lung carcinoma. Clinical trial information: NCT03373760 .

POLO: Radiologic assessment of the impact of maintenance olaparib in patients (pts) with metastatic pancreatic cancer (mPaC)

e16800

Background: The Phase III POLO study (NCT02184195) demonstrated a benefit of maintenance olaparib over placebo in the radiologically assessed primary endpoint of progression-free survival (PFS) in pts with mPaC (median 7.4 vs 3.8 months [mo]; 12-mo rate 34% vs 15%). The impact of radiologic assessment of pancreatic lesions, which is considered challenging, was explored. Methods: Tumors were assessed using Response Evaluation Criteria in Solid Tumors version 1.1 by blinded independent central review (BICR) in pts with mPaC treated with maintenance olaparib or placebo. PFS was analyzed in subsets of pts based on various event criteria. Results: All 154 randomized pts had mPaC prior to chemotherapy, of whom 122 had disease in the pancreas at POLO baseline (BL); 34% (53/154) had pancreas-only target lesions (TL), 26% (40/154) also had ≥1 TL outside of the pancreas, and in 19% (29/154) pancreatic disease was recorded as non-TL. Sensitivity analyses were consistent with the primary PFS analysis (Table), including when all pancreas lesion assessments were discounted (median PFS 7.4 vs 4.7 mo; 12-mo rate 38% vs 22%). Of 53 pts with pancreas-only TLs at BL, 34 had disease progression (PD); in 20 pts this was not solely based on TL measurements (16 had new lesions; 4 had multiple-cause PD). Confirmed objective responses occurred during study maintenance treatment in 20% of olaparib pts (18/92) and 10% of placebo pts (6/62). In pts with pancreas-only TLs at BL there were 7 responses in the olaparib arm (1 complete response [CR], 6 partial responses [PR]) and 2 (2 PR) in the placebo arm. In pts who had ≥1 TL outside of the pancreas at BL there were 11 (1 CR, 10 PR) and 4 (4 PR) responses, respectively. Responses were generally durable irrespective of TL location. Conclusions: The significant PFS benefit with maintenance olaparib over placebo shown in the primary analysis was consistent across all sensitivity analyses and was not impacted by radiologic assessment of pancreatic TLs. Taken together, these findings suggest that contrary to historically held belief, primary pancreas TLs may be appropriate for inclusion as sites of RECIST-evaluable disease and for assessment of treatment outcome. Clinical trial information: NCT02184195 . [Table: see text]

The potential in artificial intelligence-driven radiomic signature to predict survival in patients with metastatic colorectal cancer treated with cetuximab-based therapy

247

Background: This analysis was undertaken to forecast survival and enhance treatment decisions for patients (pts) with colorectal cancer (CRC) with liver metastases sensitive to folinic acid, fluorouracil and irinotecan (FOLFIRI) alone [F] or in combination with cetuximab [FC] using simple quantitative radiomic changes between CT scans at baseline and 8 weeks. Methods: We retrospectively analyzed 667 pts with KRAS-unselected metastatic CRC in NCT00154102 treated with F and FC. CT quality was classified as high (HQ) or standard (SQ), and four data sets were created and named by treatment quality. Pts were randomly assigned 1:2 to training or validation sets: FCHQ, 38/78 pts; FCSQ, 62/124 pts; FHQ, 51/78 pts; FSQ, 78/158 pts. A machine-learning signature was trained using data set FCHQ to classify pts as treatment-sensitive or treatment-insensitive using just 4 of 3,499 potential radiomic imaging features. Performance was calibrated/validated using ROC curves. Hazard ratios (HRs) and Cox regression models were used to evaluate association with overall survival (OS). Results: The signature used decrease in tumor heterogeneity plus boundary infiltration to successfully predict sensitivity to FC (FCHQ: AUC, 0.80; FCSQ: AUC, 0.72) but failed with non-cetuximab regimens (FHQ: AUC, 0.59; FSQ: AUC, 0.55). The radiomic signature outperformed existing biomarkers ( KRAS mutational status and tumor shrinkage by RECIST 1.1) for sensitivity to cetuximab-based therapy and was strongly associated with OS in the cetuximab-containing sets FCHQ (HR, 44.3; p = 0.0001) and FCSQ (HR, 6.5; p = 0.005). Conclusions: This signature, derived from simple radiomic analysis of tumor imaging phenotype using only standard-of-care CT scans, appeared to be treatment-specific and was superior to all tested prognostic biomarkers. The signature provided early prediction of sensitivity and survival and could be used to guide treatment continuation decisions.

Prospective randomized phase II trial of pazopanib versus placebo in patients with progressive carcinoid tumors (CARC) (Alliance A021202)

4005

Background: Patients (pts) with progressive advanced well-differentiated neuroendocrine tumors arising outside of the pancreas have limited systemic treatment options. Pazopanib (PZ) is an oral multi-kinase inhibitor with activity against VEGFR-2,-3, PDGFR-α, and β, and c-KIT, with initial data suggesting efficacy in CARC. Methods: This was a multicenter, randomized, double-blind, phase II study of PZ (800 mg/day) versus placebo (PL) in progressive CARC. Key eligibility: low-intermediate grade CARC, radiologic progressive disease (PD) < 12 months (mo), and adequate end-organ function. Prior somatostatin analog (SSA) mandated for midgut tumors. Concurrent SSA allowed if previous PD on SSA documented. Primary endpoint was progression-free survival (PFS), defined as time from randomization to PD by central review or death. Secondary endpoints included overall survival (OS), objective response rate (ORR) and safety. The trial had 85% power to detect a difference in median PFS of 14 v 9 mo (hazard ratio [HR] 0.64) at one-sided alpha = 0.1. A stratified log-rank test based on the intend-to-treat (ITT) principle was used. Unblinding and crossover were allowed if PD confirmed by central review. Results: 171 (97 PZ, 74 PL) pts were randomized between 6/2013-10/2015: median age 63; 56% female; 66% small bowel primary; 87% concurrent SSA. Median follow-up of 31 mo; 112 (56 PZ, 56 PL) PFS events observed. 6 pts (4 PZ, 2 PL) remain on initial treatment. Median PFS was 11.6 and 8.5 mo in PZ and PL, respectively (HR = 0.53, 1-sided 90% upper confidence limit [UCL] 0.69, p = 0.0005) which crossed the pre-specified protocol efficacy boundary. 49 PL pts received PZ after PD. Median OS was 41 and 42 mo in PZ and PL, respectively (HR = 1.13, 1-sided 90% UCL 1.51, p = 0.70). RR data will be presented. Notable grade 3+ adverse events were (PZ v. PL %) hypertension (35 v. 8), fatigue (11 v. 4), ALT (10 v. 0), AST (10 v. 0), and diarrhea (7 v. 4). Conclusions: PZ compared to PL was associated with significant improvement in PFS in patients with progressive CARC. The results confirm that VEGF signaling pathway is a valid target for therapy in CARC. Support: U10CA180821, U10CA180882 https://acknowledgments.alliancefound.org . Clinical trial information: NCT01841736.

A phase II study for prostate cancer monitoring using 18F-DCFPyL and blood-based biomarkers

TPS3154

Background: Assessing treatment response in castrate resistant prostate cancer (CRPC), remains a challenge due to the limited sensitivity and specificity of existing imaging modalities. Understanding prostate cancer biology with tumor biopsies does not address the issue of tumor heterogeneity or cellular degradation during the decalcification process of bone biopsies. Next generation positron emission tomography (PET) imaging and circulating biomarkers might provide additional insights on treatment responses and inform clinical decision-making earlier in therapy. 18F-DCFPyL (PyL) is a second-generation fluorinated PSMA PET tracer that has superior sensitivity and specificity to detect prostate cancer compared to standard imaging. Its role in assessing tumor response to therapy has not been evaluated. Circulating tumor DNA (ctDNA) in blood can provide tumor genomic information, while exosomes in serum and urine may provide data on the proteomic landscape of tumors. Methods: We are conducting a prospective study of 15 men with metastatic CRPC who are scheduled to start a new systemic therapy for their disease. Upon enrollment, subjects will have baseline assessments with standard cross-sectional imaging, 99mTc bone scan, and blood work. Standard scans will be performed every 8-12 weeks until progression of disease. PyL PET/CT scans and liquid biopsies (ctDNA and exosomes) will occur at baseline, 6 weeks after starting their new therapy, and at disease progression. Lesions seen on PET/CT images will be identified by a certified reader. The maximum standardized uptake value (SUVmax) will be measured and recorded in up to the five hottest lesions and normalized to a background SUVmean measured in the liver, spleen, kidney, mediastinum, and parotid glands. Changes in the normalized SUV from baseline to the 6-week PyL PET scan will be correlated to PSA response by the Pearson’s correlation coefficient. The Kaplan-Meier method will be used to evaluate progression free survival and overall survival dichotomized by the median value of SUV change. Blood for ctDNA and exosomes will be stored for future analysis. The study is open with two patients enrolled at the time of submission. One patient has completed his initial PyL PET/CT scan. Clinical trial information: NCT03585114.

A phase II study of talazoparib (BMN 673) in patients with homologous recombination repair deficiency (HRRD) positive stage IV squamous cell lung cancer (Lung-MAP Sub-Study, S1400G)

9022

Background: This signal finding study was designed to evaluate the clinical efficacy of a PARP inhibitor, talazoparib, in advanced stage squamous cell lung cancer harboring HRRD. Methods: Eligible patients (pts) identified through the parent S1400 screening platform were required to have a deleterious mutation in any of the study-defined HRR genes [ATM, ATR, BARD1, BRCA1, BRCA2, BRIP1, CHEK1, CHEK2, FANCA, FANCC, FANCD2, FANCF, FANCM, NBN (NBS1), PALB2, RAD51, RAD51B (RAD51L1), RAD54L, RPA1) defined as the full eligible population (FEP). The primary analysis population (PAP) is defined by a subset of genes [ATM, ATR, BRCA1, BRCA2, PALB2]. Pts have platinum sensitive disease (at least stable disease on platinum doublet) and progressed on most recent line of systemic therapy, a Zubrod performance status of 0-1, adequate organ function, and not have been previously exposed to a PARP inhibitor and not be on systemic therapy within 21 days of registration. A 2-stage design with exact 93% power and 1-sided 0.07 level type I error required enrollment of 40 patients in the PAP in order to rule out an ORR of 15% or less if the true ORR is 35% or greater. At least 3 or more responses were needed in the first 20 pts in order to proceed to full enrolment of 40 pts in the PAP. The total accrual goal was 60 FEP assuming 67% of patients would be in the PAP. Results: The study enrolled 51 patients of whom 47 are eligible and analyzable for response (FEP) with 24 in the PAP. In the FEP, median age 66.7 yrs; M/F 39/8 (83/17%); 85% White and 15% Black; 77% of the pts received at least 1 prior line of treatment for stage IV. The study was closed for futility with only one response in the PAP. In the PAP (n = 24, median age 68 yrs), ORR was 4% (95%CI: 0, 21) and DCR was 54% (95%CI: 33, 74); median PFS of 2.4 months (95%CI: 1.5-2.8) and median OS was 5.2 months (95%CI: 3.8-10, 7). There were five responders in the FEP with ORR of 11%; DCR of 53% and median DoR was 1.8 months (95% CI: 1.3, 4.2); median PFS was 2.5 months (95%CI: 1.6-3.0) and median OS was 5.7 months (95% CI: 4.5-8.7). The most frequent grade ≥3 adverse event in the FEP were: Anemia (14.9%), thrombocytopenia (12.8%); lymphopenia (8.5%) and nausea (6.4%). Conclusions: S1400G failed to show sufficient level of efficacy for talazoparib in a biomarker defined subset of squamous lung cancer with HRRD. There were no new safety signals and hematologic toxicities were the most frequent adverse events. Clinical trial information: NCT02154490.

Role of radiomics to differentiate benign from malignant pheochromocytomas and paragangliomas on contrast enhanced CT scans

e14596

Background: Radiomics features, which are quantitative features generated by computational analysis of routine clinical imaging like CT scans, have been shown to be associated with clinical outcomes and tumor’s behavior in some solid tumors. We compared the radiomic features of malignant and benign pheochromocytomas/paragangliomas (P/P). Methods: Through an IRB approved study at our institution, we identified 20 consecutive patients with P/P and with available contrast-enhanced abdominopelvic CT. A radiologist with experience in oncologic imaging identified and segmented tumors on every slice using a MatLab-based imaging platform. The entire tumor image then underwent computational analysis generating 1160 radiomics features reflecting tumor size, shape, density, textural heterogeneity, and margins. These radiomics features were compared between malignant and benign P/P using Wilcoxon-Rank sum test. Results: Of the twenty patients included in this analysis, there were 6 patients with malignant P/P and 14 patients with benign tumors. Patients had been followed for at least 5 and many for at least 10 years after resection of the tumor. At diagnosis, the mean age of patients with benign and malignant tumors were 51 and 45, respectively. A 60% majority of patients with benign tumors were females while a 77% majority of patients with malignant tumors were male. Benign P/P were significantly different from malignant ones in: tumor intensity textures (spatial correlation [p-value = 0.0010], Laws [p-value = 0.0064], LoG [p-value = 0.0087], and Gabor [p-value = 0.0325]), and tumor local surface shape (Shape Index SI7 [p-value = 0.0325]). Conclusions: This initial analysis sought to discern differences in these rare tumors that might be exploited clinically. The results show that compared to benign tumors, malignant P/P tend to have more heterogenous texture, irregular edges, and less rounded shape on contrast enhanced abdominal CT scan. However, because these radiomics phenotype properties are subtle, they cannot be made reliably in an objective fashion using human visual assessment and thus these radiomics features may have a role as a quantitative imaging biomarker in P/P to predict tumor behavior. The cohort is being expanded and data will be updated at the time of the presentation. With larger numbers, the contribution to the radiomics profile of a SDHx mutation will be explored in greater depth to understand the differential impact of SDHx loss and of evolution into a cancer to the radiomics profiles.

A phase III randomized study of nivolumab plus ipilimumab versus nivolumab for previously treated patients with stage IV squamous cell lung cancer and no matching biomarker (Lung-MAP Sub-Study S1400I, NCT02785952)

9014

Background: Lung-MAP is a master protocol for patients (pts) with stage IV previously treated SqNSCLC. S1400I enrolled pts who were not eligible for a biomarker-matched sub-study. Methods: S1400I is phase III randomized trial for immunotherapy-naïve patients with ECOG 0-1 not selected by PD-L1 expression. Pts were assigned 1:1 to nivolumab and ipilimumab (N+I) vs nivolumab (N). N was given at 3 mg/kg q 2w, I was given at 1 mg/kg q 6w. The primary endpoint was overall survival (OS). Secondary endpoints: investigator-assessed progression-free survival (IA-PFS), response by RECIST 1.1, and toxicity. Results: From December 18, 2015 to April 23, 2018, 275 pts enrolled and 252 determined eligible (125 N+I and 127 N). The study was closed for futility at an interim analysis. Baseline characteristics were similar across arms. mOS was 10.0 m (8.0-12.8) and 11.0 m (8.2-13.5) for N+I and N. HR 0.97 (0.71-1.31), p 0.82. mPFS was 3.8 m (2.3-4.2) and 2.9 m (1.8-3.9) for N+I and N. HR 0.84 (0.64-1.09), p 0.19. Outcomes based on PD-L1 and TBM subsets are shown in table. Response rates were 18% (12-25%) and 17% (11-24%) for N+ I and N. Median follow up for patients still alive was 17.4 m. Grade ≥3 treatment-related AEs occurred in 48(39%) of pts on N+I vs 38(31%) on N. irAE reported in 39% of pts on N+I and 34% of patients on N. Drug-related AEs led to discontinuation in 25% and 16% of pts on N+I and N. There were 5 grade 5 AE in N+I arm and 1 in N arm. Conclusions: S1400I failed to show improvement in outcomes with N+I. Study was closed for futility at interim analysis. Toxicities were not different between two arms. Clinical trial information: 02785952. [Table: see text]

Phase II study of ABBV-399 (Process II) in patients with C-MET positive stage IV/recurrent lung squamous cell cancer (SCC): LUNG-MAP sub-study S1400K (NCT03574753)

9075

Background: Lung-MAP is a platform trial to assess targeted therapies in SCC. S1400K was designed to evaluate the response to ABBV-399, an antibody-drug conjugate targeting C-MET, in patients with C-Met positive SCC. Methods: Patients with previously treated SCC with c-MET positive tumors (H score ≥150, Ventana SP44 assay), PS≤1, adequate organ function, peripheral neuropathy ≤ grade (G) 2, edema ≤ G2, albumin ≥3 g/dL, hepatic involvement by tumor < 50%. Patients were enrolled into 2 cohorts: Cohort 1 (immune checkpoint inhibitor (ICI) naïve) and cohort 2 (ICI refractory). ABBV-399 2.7 mg/kg was administered intravenously over 30 minutes every 3 weeks until disease progression or unacceptable toxicity. Response assessments were performed every 6 weeks. The primary endpoint was response by RECIST 1.1. Secondary endpoints included progression-free survival (PFS), overall survival (OS), response within cohort, duration of response (DoR), and toxicities associated with ABBV-399. Interim analysis was planned after 20 evaluable patients, with ≥ 3 responses needed to continue enrollment. Results: Between 2/15/18 and 10/16/2018, 50 patients (17% of patients screened) were assigned to S1400K, 28 patients enrolled (15 in cohort 1 and 13 in cohort 2), 25 were determined eligible, of whom 23 received ABBV-399 and were assessed for adverse events. There were 3 G5 events (2 pneumonitis, both in cohort 2 and 1 bronchopulmonary hemorrhage) and 4 G3 events. S1400K was temporarily closed on 10/16/2018 for interim analysis and safety concerns, and formally closed on 12/21/2018. Two responses were reported, both in cohort 1 (1 complete and 1 unconfirmed partial response, CR and UPR) for a response rate of 9% (95% CI: 0-20%). The CR remains on treatment at 4 months and DoR for the UPR was 2.3 months. Ten patients had stable disease and disease control rate was 52% (3-73%). The median OS and PFS were 4.7 and 2.4 months. Conclusions: ABBV-399 failed to meet the pre-specified response needed to justify continuing enrollment. Pneumonitis was an unanticipated toxicity observed in patients with SCC with previous immunotherapy exposure. Clinical trial information: NCT03574753.

Evaluation of clinical endpoints as surrogates for overall survival in patients treated with immunotherapies

e14557

Background: In immuno-oncology (IO), the correlation between clinical trial endpoints, specifically, objective response rate (ORR), disease control rate (DCR) or progression free survival (PFS), and overall survival (OS) is poorly understood. The effect of IO agents as opposed to chemotherapy, is not on tumor cells, but on immune cells and OS benefit has been observed in absence of PFS benefit. However, decisions on registration trials often rely on PFS from Phase II trials. Methods: We conducted a systematic literature review with PubMed and Embase (Jan. 2005–Nov. 2016), supplemented with oncology conference proceedings (2014–2016). Eligible studies were randomized controlled trials (RCT) that investigated ≥1 immune checkpoint blockers (CBs) targeting programmed death proteins (PD-1/PD-L1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), and reported their relative effect on OS and on ≥1 of the clinical endpoints, DCR, ORR, and PFS. Log-transformed hazard ratios were fitted using weighted regression models to determine the power of relative effects on clinical endpoints to predict OS effects, with correlation coefficients estimated and presented with adjusted R2 (high values indicating better goodness-of-fit). Results: This analysis included 18 RCTs involving 7140, patients. Most studies (10/18) evaluated the efficacy of CBs vs conventional chemotherapy, whereas 8 studies compared the efficacy of ≥1 CB. Among trials that evaluated anti-CTLA-4, the adjusted R2 for the relative efficacy of CBs on DCR, ORR, PFS, and relative efficacy of CBs on OS were 0.160 ( P= 0.156), 0.016 ( P= 0.332), and 0.000 ( P= 0.623) respectively. Among trials that evaluated either anti-PD-1 or anti-PD-L1, the adjusted R2 were 0.038 ( P= 0.401), 0.066 ( P= 0.251), and 0.432 ( P= 0.032), for DCR, ORR and PFS respectively. Among trials that evaluated CBs in melanoma, the adjusted R2 were 0.030 ( P= 0.267), 0.028 ( P= 0.279), and 0.192 ( P= 0.154), for DCR, ORR, and PFS respectively. Conclusions: No clear correlations were observed between relative effects of conventional clinical endpoints and OS for CBs. New surrogate endpoints may be needed to better predict OS benefit for CBs and other forms of cancer immunotherapy.

A Multiparametric Model for Mapping Cellularity in Glioblastoma Using Radiographically Localized Biopsies

BACKGROUND AND PURPOSE

The complex MR imaging appearance of glioblastoma is a function of underlying histopathologic heterogeneity. A better understanding of these correlations, particularly the influence of infiltrating glioma cells and vasogenic edema on T2 and diffusivity signal in nonenhancing areas, has important implications in the management of these patients. With localized biopsies, the objective of this study was to generate a model capable of predicting cellularity at each voxel within an entire tumor volume as a function of signal intensity, thus providing a means of quantifying tumor infiltration into surrounding brain tissue.

MATERIALS AND METHODS

Ninety-one localized biopsies were obtained from 36 patients with glioblastoma. Signal intensities corresponding to these samples were derived from T1-postcontrast subtraction, T2-FLAIR, and ADC sequences by using an automated coregistration algorithm. Cell density was calculated for each specimen by using an automated cell-counting algorithm. Signal intensity was plotted against cell density for each MR image.

RESULTS

T2-FLAIR (r = -0.61) and ADC (r = -0.63) sequences were inversely correlated with cell density. T1-postcontrast (r = 0.69) subtraction was directly correlated with cell density. Combining these relationships yielded a multiparametric model with improved correlation (r = 0.74), suggesting that each sequence offers different and complementary information.

CONCLUSIONS

Using localized biopsies, we have generated a model that illustrates a quantitative and significant relationship between MR signal and cell density. Projecting this relationship over the entire tumor volume allows mapping of the intratumoral heterogeneity in both the contrast-enhancing tumor core and nonenhancing margins of glioblastoma and may be used to guide extended surgical resection, localized biopsies, and radiation field mapping.

Comparative Effects of CT Imaging Measurement on RECIST End Points and Tumor Growth Kinetics Modeling

Quantitative assessments of tumor burden and modeling of longitudinal growth could improve phase II oncology trials. To identify obstacles to wider use of quantitative measures we obtained recorded linear tumor measurements from three published lung cancer trials. Model-based parameters of tumor burden change were estimated and compared with similarly sized samples from separate trials. Time-to-tumor growth (TTG) was computed from measurements recorded on case report forms and a second radiologist blinded to the form data. Response Evaluation Criteria in Solid Tumors (RECIST)-based progression-free survival (PFS) measures were perfectly concordant between the original forms data and the blinded radiologist re-evaluation (intraclass correlation coefficient = 1), but these routine interrater differences in the identification and measurement of target lesions were associated with an average 18-week delay (range, -20 to 55 weeks) in TTG (intraclass correlation coefficient = 0.32). To exploit computational metrics for improving statistical power in small clinical trials will require increased precision of tumor burden assessments.

Semiautomated volumetric measurement on postcontrast MR imaging for analysis of recurrent and residual disease in glioblastoma multiforme

BACKGROUND AND PURPOSE

A limitation in postoperative monitoring of patients with glioblastoma is the lack of objective measures to quantify residual and recurrent disease. Automated computer-assisted volumetric analysis of contrast-enhancing tissue represents a potential tool to aid the radiologist in following these patients. In this study, we hypothesize that computer-assisted volumetry will show increased precision and speed over conventional 1D and 2D techniques in assessing residual and/or recurrent tumor.

MATERIALS AND METHODS

This retrospective study included patients with native glioblastomas with MR imaging performed at 24-48 hours following resection and 2-4 months postoperatively. 1D and 2D measurements were performed by 2 neuroradiologists with Certificates of Added Qualification. Volumetry was performed by using manual segmentation and computer-assisted volumetry, which combines region-based active contours and a level set approach. Tumor response was assessed by using established 1D, 2D, and volumetric standards. Manual and computer-assisted volumetry segmentation times were compared. Interobserver correlation was determined among 1D, 2D, and volumetric techniques.

RESULTS

Twenty-nine patients were analyzed. Discrepancy in disease status between 1D and 2D compared with computer-assisted volumetry was 10.3% (3/29) and 17.2% (5/29), respectively. The mean time for segmentation between manual and computer-assisted volumetry techniques was 9.7 minutes and <1 minute, respectively (P < .01). Interobserver correlation was highest for volumetric measurements (0.995; 95% CI, 0.990-0.997) compared with 1D (0.826; 95% CI, 0.695-0.904) and 2D (0.905; 95% CI, 0.828-0.948) measurements.

CONCLUSIONS

Computer-assisted volumetry provides a reproducible and faster volumetric assessment of enhancing tumor burden, which has implications for monitoring disease progression and quantification of tumor burden in treatment trials.

Contrast-enhanced ultrasound monitoring of perfusion changes in hepatic neuroendocrine metastases after systemic versus selective arterial 177Lu/90Y-DOTATOC and 213Bi-DOTATOC radiopeptide therapy

AIM

Radiopeptide therapy with beta emitter labeled (177)Lu/(90)Y- DOTA(0)-Phe(1)-Tyr(3)-octreotide (DOTATOC) and more recently also alpha emitting (213)Bi-DOTATOC are promising new treatments for neuroendocrine tumors. No early predictors for treatment response have been recognized and tumor-shrinkage after radiation therapy appears slowly. In some solid tumors a decline in tumor perfusion was found predictive of final treatment response but the gold standard multiphase computed tomography (CT) has a high radiation burden. Therefore we evaluated the ability of contrast-enhanced ultrasound (CEUS) to evaluate tumor perfusion as a response criteria.

MATERIALS AND METHODS

14 patients with hepatic neuroendocrine tumor (NET) metastases were enrolled in the retrospective study. Eleven patients were treated with beta-emitting (177)Lu/(90)Y-DOTATOC, either intravenous (i.v.) (n = 5) or intra-arterial (i.a.) (n = 6) and three patients received alpha-emitting (213)Bi-DOTATOC (i.a.). CEUS and contrast-enhanced CT (CE-CT) were performed before and 3 months after treatment.

RESULTS

CE-CT and CEUS presented comparable results in the baseline study and in the assessment of perfusion changes due to the different treatment regimes. A therapy related decrease in tumor perfusion is an early predictor of longterm morphologic response.

CONCLUSION

CEUS is available and radiation free technique which showed comparable results for perfusion and diameter of liver metastases compared to CE-CT. Intensity reduction in an arterial phase CEUS can be seen as a positive sign indicating long term tumor response to treatment. Therefore CEUS may be considered as an imaging modality for monitoring early treatment after focal alpha and beta targeted therapy.

Impact of peptide receptor radionuclide therapy on the 68Ga-DOTATOC-PET/CT uptake in normal tissue

AIM

Positron-emission tomography/computed tomography (PET/CT) with [68Ga]DOTA0-Phe1-Tyr3-octreotide (68Ga-DOTA-TOC) became a standard for somatostatin receptor imaging. We investigated the potential changes of normal tissue uptake in patients with neuroendocrine tumor undergoing peptide receptor radionuclide therapy (PRRT).

METHODS

Sixteen patients underwent [68Ga]-DOTA-TOC-PET/CT prior and after 4-6 cycles of PRRT (mean administered activity: 13.8 GBq 90Y+ 9.6 177Lu). The maximum standardized uptake values (SUVmax) of pituitary, thyroid, spleen, liver parenchyma, pancreas, kidneys and adrenals were determined, respectively.

RESULTS

SUVmax values prior and after PRRT were in pituitary (5, 56±2,91/ 4,47±2,53), thyroid (2.05±1.11/ 2.49±2.47), spleen (24.95±14.20/20.06±8.53), liver (7.13±3.96/6.62±2.63), pancreas (6.96±1.99/6.83±2.00), kidneys (13.0±3.85/11.31±3.31) and adrenals (9.65± 4.20/7.10±2.86). A comparison of pre- and post treatment values revealed no significant differences (P>0.05) in any of these organs.

CONCLUSION

The uptake of [68Ga] DOTA-TOC in normal tissue is not significantly affected by PRRT. This is relevant with regards to therapeutic monitoring were tumor-to-non-tumor ratio seems to be the most robust biomarker.

Assessment of neurovascular involvement by malignant musculoskeletal tumors

Determining the presence or absence of neurovascular involvement by a malignant musculoskeletal neoplasm is an important aspect of local tumor staging. This article discusses issues concerning such assessments made by diagnostic imaging techniques, including factors inherent to the patient and those related to imaging technology. The distinction between tumor contact and tumor encasement is emphasized and illustrated.

MR Imaging of Bone Marrow in Patients with Musculoskeletal Tumors

Knowledge of the appearances of normal bone marrow, metastases involving marrow, and therapy-related marrow changes shown by MR imaging is necessary in order to avoid misdiagnosis. This article reviews MR imaging techniques and the findings that allow distinction of normal yellow (fatty) marrow and red marrow from tumor in marrow, as well as the identification of marrow changes resulting from radiation therapy or treatment with marrow-stimulating drugs in patients with musculoskeletal tumors.

Soft tissue edema around musculoskeletal sarcomas at magnetic resonance imaging

The presence of soft tissue edema around a malignant musculoskeletal neoplasm can interfere with accurate local tumor staging at magnetic resonance imaging. This article discusses and illustrates such edema, emphasizing means for avoiding misinterpretation of edema and subsequent overstaging.

Prognostic significance of adrenal gland morphology at CT in patients with three common malignancies

OBJECTIVES

To determine whether minor alterations in adrenal gland morphology at baseline CT in three common cancers indicate early metastasis.

METHODS

689 patients (237 with lung cancer, 228 with breast cancer, 224 with melanoma) underwent baseline and follow-up CTs that included the adrenals. Two readers independently scored each adrenal at baseline CT as normal, smoothly enlarged, nodular or mass-containing. Adrenals containing a mass >10 mm were excluded. The appearance of each adrenal on the latest available CT was assessed for change since baseline. Cox models were used to assess the association between adrenal morphology at initial CT and subsequent development of adrenal metastasis (defined as new mass >10 mm, corroborated by follow-up imaging). κ statistics were calculated to assess inter-reader agreement.

RESULTS

Initial and follow-up CT evaluations were recorded for 1317 adrenals (median follow-up, 18.6 months). At initial CT, Readers 1 and 2 interpreted 1242 and 1230 adrenals as normal, 40 and 57 as smoothly enlarged, 29 and 25 as nodular, and 6 and 5 as containing masses ≤ 10 mm, respectively. κ-values were 0.52 (moderate) at initial CT and 0.70 (substantial) at follow-up. The hazard ratio for developing a metastasis at follow-up CT given an abnormal adrenal assessment at baseline was 0.7 [95% confidence interval (CI) 0.2-2.1; p = 0.47] for Reader 1, and 2.0 (95% CI 0.8-4.7; p = 0.12) for Reader 2.

CONCLUSION

Minor morphological abnormalities of adrenals at initial CT did not represent early adrenal metastasis in most patients in this population.

Data sets for the qualification of volumetric CT as a quantitative imaging biomarker in lung cancer

The drug development industry is faced with increasing costs and decreasing success rates. New ways to understand biology as well as the increasing interest in personalized treatments for smaller patient segments requires new capabilities for the rapid assessment of treatment responses. Deployment of qualified imaging biomarkers lags apparent technology capabilities. The lack of consensus methods and qualification evidence needed for large-scale multi-center trials, as well as the standardization that allows them, are widely acknowledged to be the limiting factors. The current fragmentation in imaging vendor offerings, coupled with the independent activities of individual biopharmaceutical companies and their contract research organizations (CROs), may stand in the way of the greater opportunity were these efforts to be drawn together. A preliminary report, "Volumetric CT: a potential biomarker of response," of the Quantitative Imaging Biomarkers Alliance (QIBA) activity was presented at the Medical Imaging Continuum: Path Forward for Advancing the Uses of Medical Imaging in the Development of New Biopharmaceutical Products meeting of the Extended Pharmaceutical Research and Manufacturers of America (PhRMA) Imaging Group sponsored by the Drug Information Agency (DIA) in October 2008. The clinical context in Lung Cancer and a methodology for approaching the qualification of volumetric CT as a biomarker has since been reported [Acad. Radiol. 17, 100-106, 107-115 (2010)]. This report reviews the effort to collect and utilize publicly available data sets to provide a transparent environment in which to pursue the qualification activities in such a way as to allow independent peer review and verification of results. This article focuses specifically on our role as stewards of image sets for developing new tools.

Regional chemotherapy for unresectable primary liver cancer: results of a phase II clinical trial and assessment of DCE-MRI as a biomarker of survival

BACKGROUND

This study reports the results of hepatic arterial infusion (HAI) with floxuridine (FUDR) and dexamethasone (dex) in patients with unresectable intrahepatic cholangiocarcinoma (ICC) or hepatocellular carcinoma (HCC) and investigates dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) assessment of tumor vascularity as a biomarker of outcome.

PATIENTS AND METHODS

Thirty-four unresectable patients (26 ICC and eight HCC) were treated with HAI FUDR/dex. Radiologic dynamic and pharmacokinetic parameters related to tumor perfusion were analyzed and correlated with response and survival.

RESULTS

Partial responses were seen in 16 patients (47.1%); time to progression and response duration were 7.4 and 11.9 months, respectively. Median follow-up and median survival were 35 and 29.5 months, respectively; 2-year survival was 67%. DCE-MRI data showed that patients with pretreatment integrated area under the concentration curve of gadolinium contrast over 180 s (AUC 180) >34.2 mM.s had a longer median survival than those with AUC 180 <34 mM.s (35.1 versus 19.1 months, P = 0.002). Decreased volume transfer exchange between the vascular space and extracellular extravascular space (-DeltaK(trans)) and the corresponding rate constant (-Deltak(ep)) on the first post-treatment scan both predicted survival.

CONCLUSIONS

In patients with unresectable primary liver cancer, HAI therapy can be effective and safe. Pretreatment and early post-treatment changes in tumor perfusion characteristics may predict treatment outcome.

New response evaluation criteria in solid tumours: revised RECIST guideline (version 1.1)

BACKGROUND

Assessment of the change in tumour burden is an important feature of the clinical evaluation of cancer therapeutics: both tumour shrinkage (objective response) and disease progression are useful endpoints in clinical trials. Since RECIST was published in 2000, many investigators, cooperative groups, industry and government authorities have adopted these criteria in the assessment of treatment outcomes. However, a number of questions and issues have arisen which have led to the development of a revised RECIST guideline (version 1.1). Evidence for changes, summarised in separate papers in this special issue, has come from assessment of a large data warehouse (>6500 patients), simulation studies and literature reviews. HIGHLIGHTS OF REVISED RECIST 1.1: Major changes include: Number of lesions to be assessed: based on evidence from numerous trial databases merged into a data warehouse for analysis purposes, the number of lesions required to assess tumour burden for response determination has been reduced from a maximum of 10 to a maximum of five total (and from five to two per organ, maximum). Assessment of pathological lymph nodes is now incorporated: nodes with a short axis of 15 mm are considered measurable and assessable as target lesions. The short axis measurement should be included in the sum of lesions in calculation of tumour response. Nodes that shrink to <10mm short axis are considered normal. Confirmation of response is required for trials with response primary endpoint but is no longer required in randomised studies since the control arm serves as appropriate means of interpretation of data. Disease progression is clarified in several aspects: in addition to the previous definition of progression in target disease of 20% increase in sum, a 5mm absolute increase is now required as well to guard against over calling PD when the total sum is very small. Furthermore, there is guidance offered on what constitutes 'unequivocal progression' of non-measurable/non-target disease, a source of confusion in the original RECIST guideline. Finally, a section on detection of new lesions, including the interpretation of FDG-PET scan assessment is included. Imaging guidance: the revised RECIST includes a new imaging appendix with updated recommendations on the optimal anatomical assessment of lesions.

FUTURE WORK

A key question considered by the RECIST Working Group in developing RECIST 1.1 was whether it was appropriate to move from anatomic unidimensional assessment of tumour burden to either volumetric anatomical assessment or to functional assessment with PET or MRI. It was concluded that, at present, there is not sufficient standardisation or evidence to abandon anatomical assessment of tumour burden. The only exception to this is in the use of FDG-PET imaging as an adjunct to determination of progression. As is detailed in the final paper in this special issue, the use of these promising newer approaches requires appropriate clinical validation studies.

Evaluation of lymph nodes with RECIST 1.1

Lymph nodes are common sites of metastatic disease in many solid tumours. Unlike most metastases, lymph nodes are normal anatomic structures and as such, normal lymph nodes will have a measurable size. Additionally, the imaging literature recommends that lymph nodes be measured in the short axis, since the short axis measurement is a more reproducible measurement and predictive of malignancy. Therefore, the RECIST committee recommends that lymph nodes be measured in their short axis and proposes measurement values and rules for categorising lymph nodes as normal or pathologic; either target or non-target lesions. Data for the RECIST warehouse are presented to demonstrate the potential change in response assessment following these rules. These standardised lymph node guidelines are designed to be easy to implement, focus target lesion measurements on lesions that are likely to be metastatic and prevent false progressions due to minimal change in size.

Imaging response assessment in oncology

The role of imaging in the clinical setting as well as in the drug development process is expanding rapidly. Imaging technology now exists that is capable of detecting tumor response within hours. In parallel with this advance, a new array of more targeted and specific therapies are being developed. This paradigm shift in turn demands a more sophisticated way of quantifying response. There is a need to update and modify the current response evaluation criteria in solid tumors (RECIST), which rely solely on anatomic size measurement of tumors. In addition, response assessment guidelines will need to be increasingly disease-specific. Response assessment by imaging is now intimately involved with all stages of the drug development process, from exploratory drug discovery through clinical trials, as well as in clinical use. Imaging biomarkers and surrogate endpoints have the potential to speed drug approval significantly. The major funding institutions and the pharmaceutical industry are working more and more with researchers to help maintain progress in this multidisciplinary area involving oncologists, radiologists, molecular imaging specialists, medical physicists, and computer scientists.

Measuring tumor response and shape change on CT: esophageal cancer as a paradigm

BACKGROUND

Accurate response assessment is essential for evaluating new cancer treatments. We evaluated the impact of Response Evaluation Criteria in Solid Tumors (RECIST), World Health Organization (WHO) criteria and tumor shape on response assessment in patients with metastatic esophageal cancer.

PATIENTS AND METHODS

In 19 patients with metastatic esophageal cancer in a phase II trial of bryostatin-1 and paclitaxel, response was retrospectively assessed for 89 lesions with RECIST and WHO criteria on baseline and serial follow-up CT scans. The eccentricity factor (EF) was introduced for measuring the degree to which tumor shape diverges from a perfect sphere [EF = radical1-(LPD/MD)(2), where LPD is the largest perpendicular diameter and MD is the maximal diameter].

RESULTS

The disagreement rate in best overall response categorization between RECIST (unidimensional) and WHO (bidimensional) criteria was 26.3%. Change in eccentricity was significantly greater (P < 0.01) for patients with disagreement (mean 0.31, range 0-0.91). When the short axis was used for unidimensional lymph node measurement, disagreement between WHO and RECIST lessened.

CONCLUSIONS

Response assessment by WHO and RECIST differs substantially. Greater change in eccentricity is associated with greater discordance between WHO and RECIST. The discordance between WHO and RECIST may impact on how effective a therapy is judged to be.

Evaluation of the response to treatment of solid tumours - a consensus statement of the International Cancer Imaging Society

New guidelines to evaluate the response to treatment in solid tumors using imaging techniques have major limitations and important implications for radiological workload. This consensus statement from the International Cancer Imaging Society (ICIS) reviews the RECIST criteria and addresses several challenges regarding tumour measurement. Recommendations are made regarding tumour measurement and other issues are raised. The growing need to introduce a multimodality approach to monitoring response is recognized. ICIS welcomes a dialogue with the authors of RECIST to address issues raised in this review.

Imaging of hepatocellular carcinoma: a practical approach

Imaging of hepatocellular carcinoma (HCC) is complicated because the tumor has a varied radiologic appearance and frequently coexists with cirrhotic regenerative and dysplastic nodules. In cirrhotic patients, any dominant solid nodule that is not clearly a hemangioma should be considered a HCC until proven otherwise, especially if the lesion is hypervascular, of high T2 signal intensity, or demonstrates venous invasion. Biopsy of HCC in cirrhosis is risky and surveillance is often preferable. The doubling time of HCC is 1 to 12 months, and a nodule that is stable over 4 months is very unlikely to be a HCC. However, stable nodules cannot be dismissed, since livers containing dysplastic nodules are at high risk to develop HCC. In noncirrhotic patients, any solid mass that is not clearly a hemangioma or focal nodular hyperplasia is potentially a HCC, and biopsy may be required. Venous invasion by tumor should be distinguished from bland thrombus. Imaging detection of nodal metastases is limited by the frequent finding of benign reactive lymphadenopathy in cirrhosis. Resection is the preferred treatment for HCC, but is contraindicated in the presence of tumors in both lobes, major venous invasion, invasion of adjacent organs other than the gallbladder, tumor rupture, nodal metastases, or distant metastases.

Breast Cancer

OBJECTIVE

The purpose of this study was to determine the benefit of routine pelvic CT in the evaluation of patients with primary breast cancer and to assess the frequency with which equivocal or abnormal findings on pelvic CT prompted the performance of additional studies or procedures that yielded results relevant to patient care.

MATERIALS AND METHODS

The reports of 6628 body CT scans that included images of at least the pelvis in 2426 patients with breast cancer during a 9-year period were reviewed. The presence and sites of reported definite or probable metastases or pelvic tumors were recorded for each scan. Also, the types and results of diagnostic examinations and procedures prompted by equivocal or abnormal findings on pelvic CT were recorded.

RESULTS

Pelvic metastases shown on CT were the only known site of metastasis in 13 (0.5%) of 2426 patients, and four other patients (0.2%) had new or enlarging pelvic metastases despite the presence of stable extrapelvic metastases. The pelvic metastases in these 17 patients were located in bone only in 11 patients, in adnexa only in five patients, and in adnexa, endometrium, and bone in one patient. In addition, pelvic CT led to the performance of 204 additional radiologic examinations, including 186 pelvic sonographic examinations, and 50 surgical procedures; 215 (84.6%) of these 254 additional examinations and procedures yielded normal, benign, or indeterminate results.

CONCLUSION

The routine use of pelvic CT in the evaluation of patients with breast cancer has an extremely low yield and often prompts performance of pelvic sonographic or surgical procedures, the results of which were rarely relevant to cancer therapy.

Management of 155 patients with benign liver tumours

BACKGROUND

Benign hepatic tumours continue to represent a diagnostic and therapeutic challenge. This study evaluates the indications and results of resection compared with observation in patients with benign hepatic tumours.

METHODS

Patients with a primary diagnosis of benign liver tumour were identified from a prospective database and evaluated retrospectively.

RESULTS

From January 1992 to June 1999, 155 patients with benign hepatic tumours were evaluated. The diagnoses included haemangioma (n = 97), focal nodular hyperplasia (FNH) (n = 42), hepatic adenoma (n = 12) and cystadenoma (n = 4). Sixty-eight patients (44 per cent) underwent resection because of symptoms (n = 36), inability to exclude a malignancy (n = 31) or enlargement on serial imaging (n = 11). The operative morbidity and mortality rates were 21 per cent and zero respectively. Thirty patients had a preoperative percutaneous needle biopsy, 19 of which were either incorrect or indeterminate. Overall, 39 of 42 patients with symptoms attributed to the tumour were asymptomatic after resection and 18 of 21 patients with symptoms considered unrelated to the tumour were asymptomatic after a period of observation and/or treatment of unrelated conditions (median follow-up 16 months).

CONCLUSION

When indicated, resection of benign liver tumours can be performed safely. Symptomatic patients with a small FNH or haemangioma can be observed because their symptoms are unlikely to be related to the liver tumour. Percutaneous needle biopsy rarely changes management.

Randomized Multicenter Phase II Trial of Subcutaneous Recombinant Human Interleukin-12 Versus Interferon-α2a for Patients with Advanced Renal Cell Carcinoma

Recombinant human interleukin-12 (rHuIL-12) is a pleiotropic cytokine with anticancer activity against renal cell carcinoma (RCC) in preclinical models and in a phase I trial. A randomized phase II study of rHuIL-12 compared with interferon-alpha (IFN-alpha) evaluated clinical response for patients with previously untreated, advanced RCC. Patients were randomly assigned 2:1 to receive either rHuIL-12 or IFN-alpha2a. rHuIL-12 was administered by subcutaneous (s.c.) injection on days 1, 8, and 15 of each 28-day cycle. The dose of IL-12 was escalated during cycle 1 to a maintenance dose of 1.25 microg/kg. IFN was administered at 9 million units by s.c. injection three times per week. Serum concentrations of IL-12, IFN-gamma, IL-10, and neopterin were obtained in 10 patients treated with rHuIL-12 after the first full dose of 1.25 microg/kg given on day 15 (dose 3) of cycle 1 and again after multiple doses on day 15 (dose 6) of cycle 2. Thirty patients were treated with rHuIL-12, and 16 patients were treated with IFN-alpha. Two (7%) of 30 patients treated with rHuIL-12 achieved a partial response, and the trial was closed to accrual based on the low response proportion. IL-12 was absorbed rapidly after s.c. drug administration, with the peak serum concentration appearing at approximately 12 h in both cycles. Serum IL-12 concentrations remained stable on multiple dosing. Levels of IFN-gamma, IL-10, and neopterin increased with rHuIL-12 and were maintained in cycle 2. rHuIL-12 is a novel cytokine with unique pharmacologic and pharmacodynamic features under study for the treatment of malignancy and other medical conditions. The low response proportion associated with rHuIL-12 single-agent therapy against metastatic RCC was disappointing, given the preclinical data. Further study of rHuIL-12 for other medical conditions is underway. For RCC, the study of new cytokines is of the highest priority.

Bone marrow segmentation in leukemia using diffusion and T (2) weighted echo planar magnetic resonance imaging

Magnetic resonance images of leukemic bone marrow were acquired over large regions of the pelvis and lower abdomen with minimal interference from overlying tissues using diffusion and T(2) weighted echo planar imaging. Data acquisition times were on the order of 1 min for scanning volumes of up to 25 l at a spatial resolution of 31 microl. A survey of 21 patients with leukemia and eight healthy adult volunteers was undertaken to determine the magnitude of the observed effect and its dependence upon specific pathologies. The acquisition methods yielded high-quality segmentation of leukemic bone marrow prior to therapy in seven of seven patients with acute lymphocytic leukemia, chronic lymphocytic leukemia or chronic myelogenous leukemia, and who had hypercellular (>95%) bone marrow at the time of the study. The quality of the segmentation was sufficient to allow the use of maximum intensity projection images which afforded a convenient evaluation of both intra- and extramedullary disease. The measured signal-to-noise ratios agreed with a theoretical estimate that accounted for the percentage cellularity, T(2) relaxation time of water, and self-diffusion coefficient of water in iliac bone marrow. In addition, the mean signal-to-noise ratios from iliac marrow were strongly dependent upon the time after the initiation of chemotherapeutic regimens, implying that the methods may be useful for therapeutic monitoring.

Phase III trial of interferon alfa-2a with or without 13-cis-retinoic acid for patients with advanced renal cell carcinoma

PURPOSE

A randomized phase III trial was conducted to determine whether combination therapy with 13-cis-retinoic acid (13-CRA) plus interferon alfa-2a (IFNalpha2a) is superior to IFNalpha2a alone in patients with advanced renal cell carcinoma (RCC).

PATIENTS AND METHODS

Two hundred eighty-four patients were randomized to treatment with IFNalpha2a plus 13-CRA or treatment with IFNalpha2a alone. IFNalpha2a was given daily subcutaneously, starting at a dose of 3 million units (MU). The dose was escalated every 7 days from 3 to 9 MU (by increments of 3 MU), unless >/= grade 2 toxicity occurred, in which case dose escalation was stopped. Patients randomized to combination therapy were given oral 13-CRA 1 mg/kg/d plus IFNalpha2a. Quality of life (QOL) was assessed.

RESULTS

Complete or partial responses were achieved by 12% of patients treated with IFNalpha2a plus 13-CRA and 6% of patients treated with IFNalpha2a (P =.14). Median duration of response (complete and partial combined) in the group treated with the combination was 33 months (range, 9 to 50 months), versus 22 months (range, 5 to 38 months) for the second group (P =.03). Nineteen percent of patients treated with IFNalpha2a plus 13-CRA were progression-free at 24 months, compared with 10% of patients treated with IFNalpha2a alone (P =.05). Median survival time for all patients was 15 months, with no difference in survival between the two treatment arms (P =.26). QOL decreased during the first 8 weeks of treatment, and a partial recovery followed. Lower scores were associated with the combination therapy.

CONCLUSION

Response proportion and survival did not improve significantly with the addition of 13-CRA to IFNalpha2a therapy in patients with advanced RCC. 13-CRA may lengthen response to IFNalpha2a therapy in patients with IFNalpha2a-sensitive tumors. Treatment, particularly the combination therapy, was associated with a decrease in QOL.

Evaluation of tumor measurements in oncology: use of film-based and electronic techniques

PURPOSE

To evaluate the variability in bidimensional computed tomography (CT) measurements obtained of actual tumors and of tumor phantoms by use of three measurement techniques: hand-held calipers on film, electronic calipers on a workstation, and an autocontour technique on a workstation.

MATERIALS AND METHODS

Three radiologists measured 45 actual tumors (in the lung, liver, and lymph nodes) on CT images, using each of the three techniques. Bidimensional measurements were recorded, and their cross-products calculated. The coefficient of variation was calculated to assess interobserver variability. CT images of 48 phantoms were measured by three radiologists with each of the techniques. In addition to the coefficient of variation, the differences between the cross-product measurements of tumor phantoms themselves and the measurements obtained with each of the techniques were calculated.

RESULTS

The differences between the coefficients of variation were statistically significantly different for the autocontour technique, compared with the other techniques, both for actual tumors and for tumor phantoms. There was no statistically significant difference in the coefficient of variation between measurements obtained with hand-held calipers and electronic calipers. The cross-products for tumor phantoms were 12% less than the actual cross-product when calipers on film were used, 11% less using electronic calipers, and 1% greater using the autocontour technique.

CONCLUSION

Tumor size is obtained more accurately and consistently between readers using an automated autocontour technique than between those using hand-held or electronic calipers. This finding has substantial implications for monitoring tumor therapy in an individual patient, as well as for evaluating the effectiveness of new therapies under development.

Evaluation of pectoralis major muscle in patients with posterior breast tumors on breast MR images: early experience

PURPOSE

To evaluate the ability to use breast magnetic resonance (MR) imaging to assess disease extent in patients with posterior breast masses who are suspected to have tumor invasion into underlying muscle.

MATERIALS AND METHODS

Nineteen patients with posterior breast masses underwent three-dimensional, gradient-echo, 1.5-T MR imaging before and after the administration of gadopentetate dimeglumine. Thirteen had deep palpable masses that were clinically determined to be fixed to the underlying chest wall. Twelve had mammographic findings that caused muscle involvement to be suspected, and seven had normal mammograms. All patients underwent surgery. MR images were reviewed and were correlated with histologic findings.

RESULTS

Enhancing masses were identified on MR images in all 19 patients. Five (26%) of the 19 patients had masses that abutted the muscles, with obliteration of the fat plane and muscle enhancement. All five had muscle involvement at surgery. In the remaining 14 (74%) patients, no enhancement of muscle was seen; none of these had invasion of the muscle at surgery.

CONCLUSION

Extension of adjacent tumor into underlying musculature was indicated by abnormal enhancement within these structures. Violation of the fat plane between tumor and muscle, without other findings, did not indicate tumor involvement of these deep structures.

Deep inspiration breath-hold technique for lung tumors: the potential value of target immobilization and reduced lung density in dose escalation

PURPOSE/OBJECTIVE

This study evaluates the dosimetric benefits and feasibility of a deep inspiration breath-hold (DIBH) technique in the treatment of lung tumors. The technique has two distinct features--deep inspiration, which reduces lung density, and breath-hold, which immobilizes lung tumors, thereby allowing for reduced margins. Both of these properties can potentially reduce the amount of normal lung tissue in the high-dose region, thus reducing morbidity and improving the possibility of dose escalation.

METHODS AND MATERIALS

Five patients treated for non-small cell lung carcinoma (Stage IIA-IIIB) received computed tomography (CT) scans under 4 respiration conditions: free-breathing, DIBH, shallow inspiration breath-hold, and shallow expiration breath-hold. The free-breathing and DIBH scans were used to generate 3-dimensional conformal treatment plans for comparison, while the shallow inspiration and expiration scans determined the extent of tumor motion under free-breathing conditions. To acquire the breath-hold scans, the patients are brought to reproducible respiration levels using spirometry, and for DIBH, modified slow vital capacity maneuvers. Planning target volumes (PTVs) for free-breathing plans included a margin for setup error (0.75 cm) plus a margin equal to the extent of tumor motion due to respiration (1-2 cm). Planning target volumes for DIBH plans included the same margin for setup error, with a reduced margin for residual uncertainty in tumor position (0.2-0.5 cm) as determined from repeat fluoroscopic movies. To simulate the effects of respiration-gated treatments and estimate the role of target immobilization alone (i.e., without the benefit of reduced lung density), a third plan is generated from the free-breathing scan using a PTV with the same margins as for DIBH plans.

RESULTS

The treatment plan comparison suggests that, on average, the DIBH technique can reduce the volume of lung receiving more than 25 Gy by 30% compared to free-breathing plans, while respiration gating can reduce the volume by 18%. The DIBH maneuver was found to be highly reproducible, with intra breath-hold reproducibility of 1.0 (+/- 0.9) mm and inter breath-hold reproducibility of 2.5 (+/- 1.6) mm, as determined from diaphragm position. Patients were able to perform 10-13 breath-holds in one session, with a comfortable breath-hold duration of 12-16 s.

CONCLUSION

Patients tolerate DIBH maneuvers well and can perform them in a highly reproducible fashion. Compared to conventional free-breathing treatment, the DIBH technique benefits from reduced margins, as a result of the suppressed target motion, as well as a decreased lung density; both contribute to moving normal lung tissue out of the high-dose region. Because less normal lung tissue is irradiated to high dose, the possibility for dose escalation is significantly improved.

Advances in cross-sectional imaging of colorectal cancer

Imaging of colorectal cancer is primarily accomplished with computed tomography (CT) and magnetic resonance imaging (MRI). These two modalities have been used for more than a decade in imaging both primary and metastatic colorectal cancer. Recent advances in the CT and MRI technologies are redefining the precise role of these imaging modalities in the work-up and evaluation of patients with colorectal cancer.