Impact of MRI/US fusion-guided prostate biopsy on biopsy-naïve patients: A single urologist's experience.

Objectives: To report our experience with imaging-guided targeted prostate biopsy (IGTpBx) for patients undergoing initial prostate biopsy in a clinical setting. Materials and methods: From July 2014 to February 2020, 305 men who had IGTpBx performed as their first prostate biopsy were enrolled. Two dedicated magnetic resonance imaging (MRI) radiologists segmented at least 1 region of interest (ROI) for each of these men using screening 1.5T MRI images. A single urologist employed the robotic-assisted Artemis MRI/ultrasonography (US) fusion platform to obtain 2-3 targeted samples from each ROI and additional random samples from the zones of the prostate outside the ROIs (a total of 12 zonal samples). Biopsy outcomes were categorized based on the Gleason score (GS) grade group (GG) as no cancer, favorable (GG < 3 or GS < 4 + 3), or clinically significant (GG ≥ 3 or GS ≥ 4 + 3) cancer. Results: The overall cancer detection rate was 75%:31% clinically significant, 44% favorable, and 25% no cancer. These findings triggered active interventions in 176 (58%) patients. A prostate-specific antigen (PSA) level of 0-4 ng/mL was detected in 39 (66%) of 59 patients (32 favorable, 7 significant), 4-10 ng/mL in 147 (77%) of 190 patients (85 favorable, 62 significant), and 10 ng/mL and over in 44 (80%) of 55 patients (17 favorable, 27 significant). Conclusions: The tumor detection rate was 75% with IGTpBx in patients without a previous biopsy. In addition, about 42% of detected cancers were deemed clinically significant and led to active interventions. IGTpBx as a patient's first prostate biopsy improves the detection of clinically significant prostate cancer when compared with historical data for random systematic prostate biopsy.

Repeatability and Reproducibility Assessment of the Apparent Diffusion Coefficient in the Prostate: A Trial of the ECOG-ACRIN Research Group (ACRIN 6701).

BACKGROUND: Uncertainty regarding the reproducibility of the apparent diffusion coefficient (ADC) hampers the use of quantitative diffusion-weighted imaging (DWI) in evaluation of the prostate with magnetic resonance imaging MRI. The quantitative imaging biomarkers alliance (QIBA) profile for quantitative DWI claims a within-subject coefficient of variation (wCV) for prostate lesion ADC of 0.17. Improved understanding of ADC reproducibility would aid the use of quantitative diffusion in prostate MRI evaluation. PURPOSE: Evaluation of the repeatability (same-day) and reproducibility (multi-day) of whole-prostate and focal-lesion ADC assessment in a multi-site setting. STUDY TYPE: Prospective multi-institutional. SUBJECTS: Twenty-nine males, ages 53 to 80 (median 63) years, following diagnosis of prostate cancer, 10 with focal lesions. FIELD STRENGTH/SEQUENCE: 3T, single-shot spin-echo diffusion-weighted echo-planar sequence with four b-values. ASSESSMENT: Sites qualified for the study using an ice-water phantom with known ADC. Readers performed DWI analyses at visit 1 ("V1") and visit 2 ("V2," 2-14 days after V1), where V2 comprised scans before ("V2pre") and after ("V2post") a "coffee-break" interval with subject removal and repositioning. A single reader segmented the whole prostate. Two readers separately placed region-of-interests for focal lesions. STATISTICAL TESTS: Reproducibility and repeatability coefficients for whole prostate and focal lesions derived from median pixel ADC. We estimated the wCV and 95% confidence interval using a variance stabilizing transformation and assessed interreader reliability of focal lesion ADC using the intraclass correlation coefficient (ICC). RESULTS: The ADC biases from b0 -b600 and b0 -b800 phantom scans averaged 1.32% and 1.44%, respectively; mean b-value dependence was 0.188%. Repeatability and reproducibility of whole prostate median pixel ADC both yielded wCVs of 0.033 (N = 29). In 10 subjects with an evaluable focal lesion, the individual reader wCVs were 0.148 and 0.074 (repeatability) and 0.137 and 0.078 (reproducibility). All time points demonstrated good to excellent interreader reliability for focal lesion ADC (ICCV1  = 0.89; ICCV2pre  = 0.76; ICCV2post  = 0.94). DATA CONCLUSION: This study met the QIBA claim for prostate ADC. Test-retest repeatability and multi-day reproducibility were largely equivalent. Interreader reliability for focal lesion ADC was high across time points. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 2 TOC CATEGORY: Pelvis.

Definitive radiotherapy in lieu of systemic therapy for oligometastatic renal cell carcinoma: a single-arm, single-centre, feasibility, phase 2 trial.

BACKGROUND: The role of radiotherapy in metastatic renal cell carcinoma is controversial. We prospectively tested the feasibility and efficacy of radiotherapy to defer systemic therapy for patients with oligometastatic renal cell carcinoma. METHODS: This single-arm, phase 2, feasibility trial was done at one centre in the USA (The MD Anderson Cancer Center, Houston, TX, USA). Patients (aged ≥18 years) with five or fewer metastatic lesions, an Eastern Cooperative Oncology Group status of 0-2, and no more than one previous systemic therapy (if this therapy was stopped at least 1 month before enrolment) without limitations on renal cell carcinoma histology were eligible for inclusion. Patients were treated with stereotactic body radiotherapy (defined as ≤5 fractions with ≥7 Gy per fraction) to all lesions and maintained off systemic therapy. When lesion location precluded safe stereotactic body radiotherapy, patients were treated with hypofractionated intensity-modulated radiotherapy regimes consisting of 60-70 Gy in ten fractions or 52·5-67·5 Gy in 15 fractions. Additional rounds of radiotherapy were allowed to treat subsequent sites of progression. Co-primary endpoints were feasibility (defined as all planned radiotherapy completed with <7 days unplanned breaks) and progression-free survival. All efficacy analyses were intention-to-treat. Safety was analysed in the as-treated population. A second cohort, with the aim of assessing the feasibility of sequential stereotactic body radiotherapy alone in patients with low-volume metastatic disease, was initiated and will be reported separately. This study is registered with ClinicalTrials.gov, NCT03575611. FINDINGS: 30 patients (six [20%] women) were enrolled from July 13, 2018, to Sept 18, 2020. All patients had clear cell histology and had a nephrectomy before enrolment. All patients completed at least one round of radiotherapy with less than 7 days of unplanned breaks. At a median follow-up of 17·5 months (IQR 13·2-24·6), median progression-free survival was 22·7 months (95% CI 10·4-not reached; 1-year progression-free survival 64% [95% CI 48-85]). Three (10%) patients had severe adverse events: two grade 3 (back pain and muscle weakness) and one grade 4 (hyperglycaemia) adverse events were observed. There were no treatment-related deaths. INTERPRETATION: Sequential radiotherapy might facilitate deferral of systemic therapy initiation and could allow sustained systemic therapy breaks for select patients with oligometastatic renal cell carcinoma. FUNDING: Anna Fuller Foundation, the Cancer Prevention and Research Institute of Texas (CPRIT), and the National Cancer Institute.

Accuracy of Prostate Magnetic Resonance Imaging: Reader Experience Matters.

BACKGROUND: Prostate magnetic resonance imaging (MRI) is increasingly used in the detection, image-guided biopsy, and active surveillance of prostate cancer. The accuracy of prostate MRI may differ based on factors including imaging technique, patient population, and reader experience. OBJECTIVE: To determine whether the accuracy of prostate MRI varies with reader experience. DESIGN SETTING AND PARTICIPANTS: We rescored regions of interest from 194 consecutive patients who had undergone MRI/ultrasonography fusion biopsy. Original prostate MRI scans had been interpreted by one of 33 abdominal radiologists (AR group). More than 14 mo later, rescoring was performed by two blinded, prostate MRI radiologists (PR group). Likert scoring was used for both original MRI reports and rescoring. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Test performance (sensitivity, specificity, positive predictive value [PPV], and negative predictive value [NPV]) of prostate MRI was defined for the AR and PR groups. A Likert score of 4-5 was considered test positive and clinically significant prostate carcinoma (csPCa; Gleason grade group [GGG] ≥2) was considered outcome positive. RESULTS AND LIMITATIONS: MRI-positive lesions (Likert 4-5) scored by the PR group resulted in csPCa more frequently than those scored by the AR group (64.9% vs 39.3%). MRI-negative lesions (Likert 2-3) were more likely to result in a clinically insignificant biopsy (benign pathology or GGG 1) when scored by the PR versus the AR group (91.8% vs 76.6%). Sensitivity and specificity of MRI to detect csPCa were higher for the PR group than for the AR group (sensitivity 85.9% vs 70.7%; specificity 77.3% vs 46.8%). Overall diagnostic accuracy was higher for the PR group than for the AR group (80.1% vs 54.6%). CONCLUSIONS: Sensitivity, specificity, PPV, and NPV of prostate MRI were higher for the PR group than for the AR group. PATIENT SUMMARY: We examined the accuracy of prostate magnetic resonance imaging (MRI) in two groups of radiologists. Experienced radiologists were more likely to detect clinically significant prostate cancer on MRI.

Prospective trial of regional (hockey-stick) prostate cryoablation: oncologic and quality of life outcomes.

PURPOSE: To report long-term follow-up of the efficacy of subtotal prostate ablation using a "hockey-stick" template, including oncologic control and quality of life (QoL) impact. METHODS: We performed a prospective controlled trial to evaluate the efficacy of subtotal prostate ablation in selected men with baseline and confirmatory biopsy showing grade group (GG) 1-2 prostate cancer. "Hockey-stick" cryoablation that included the ipsilateral hemi-gland and contralateral anterior prostate was performed. Prostate biopsies and QOL queries were performed at 6, 18 and 36 months following regional ablation, and follow-up was updated to include subsequent clinic visits. RESULTS: Between August 2009 and January 2012, 72 men were screened for eligibility and 47 opted to undergo confirmatory biopsy. Of these, 23 were deemed eligible and treated with regional cryoablation. Median age was 64 years. Median follow-up was 74 months. A single patient had < 1 mm of in-field viable tumor with therapy effect on 36-month biopsy. At time of last follow-up, a total of 12/23 (52%) patients did not have evidence of disease, all patients had preserved urinary control with no patients requiring pads for urinary incontinence. Sexual decline was significant at 3 and 6 months (P < 0.01 for both), though improvement was seen at subsequent time points. CONCLUSION: Subtotal (hockey-stick template) cryoablation of the prostate provides oncologic control to targeted tissue in a generally low-risk group with minimal impact on sexual and urinary function. Further studies are needed to evaluate this ablation template in the MRI-targeted era and higher risk populations.

Comparing confirmatory biopsy outcomes between MRI-targeted biopsy and standard systematic biopsy among men being enrolled in prostate cancer active surveillance.

OBJECTIVES: To evaluate the ability of magnetic resonance imaging (MRI)-targeted biopsy combined with systematic biopsy (MRI-biopsy) to reduce negative biopsies and detect clinically significant prostate cancer compared to systematic biopsy (SB) alone in the confirmatory biopsy setting using matched cohorts. PATIENTS AND METHODS: Patients were identified from an active surveillance database who had a previously positive transrectal ultrasonography-guided SB followed by a confirmatory biopsy at a single institution between 2006 and 2019. Patients were divided into two cohorts based on confirmatory biopsy technique: SB alone or MRI-biopsy (which included MRI-targeted and systematic biopsies). Cohorts were then matched on age, prostate-specific antigen (PSA) level, number of positive cores on initial biopsy and initial biopsy Gleason grade group (GG). Logistic regression was performed to identify associations with confirmatory biopsy upgrading. RESULTS: After matching, 514 patients were identified (257 per cohort). PSA, prostate volume and PSA density prior to initial biopsy, in addition to total number of initial biopsy positive cores and GG, were similar between the matched cohorts. After confirmatory biopsy, 118/257 patients (45.9%) in the MRI-biopsy cohort were upgraded compared to 46/257 patients (17.9%) in the SB cohort (P < 0.001). The rate of negative confirmatory biopsy was 32/257 (12.5%) compared to 97/257 (37.7%) in the MRI-biopsy and SB cohorts, respectively (P < 0.001). Confirmatory MRI-biopsy was associated with greater odds of confirmatory biopsy upgrade from GG 1 to ≥GG 2 compared to SB alone (odds ratio 3.62, 95% confidence interval 1.97-6.63; P < 0.001). CONCLUSION: The addition of MRI-targeted biopsies to SB in the confirmatory biopsy setting among men with previously detected prostate cancer resulted in fewer negative confirmatory biopsies and detection of more clinically significant prostate cancer compared to SB alone.

Tumor response criteria for assessing pazopanib first-line therapy in patients with metastatic renal cell carcinoma (mRCC).

PURPOSE: To identify the optimum response criteria for first-line targeted pazopanib therapy in patients with mRCC using solid tumor response criteria and clinical risk factors. METHODS: Pre- and post-treatment CTs of patients (n = 43) with mRCC treated with first-line pazopanib therapy were analyzed retrospectively. Treatment response was evaluated with Response Evaluation Criteria in Solid Tumors (RECIST) v1.1, Choi, modified Choi (mChoi), revised Choi (rChoi), MASS (Morphology, Attenuation, Size, and Structure), 10% threshold criteria, and subjective assessment. Memorial Sloan-Kettering Cancer Center and International Metastatic Renal Cell Carcinoma Database Consortium clinical risk factors were also used to define response groups. Response evaluations were correlated with overall survival (OS) and progression-free survival (PFS) using log-rank test. RESULTS: Patients with partial response (PR) by mChoi and rChoi had longer OS than those with stable disease (SD) (P < 0.001). Responders by 10% threshold criteria also had better OS, without or combined with clinical criteria. Patients with PR by rChoi, mChoi, RECIST v1.1, MASS criteria, and by subjective assessment had longer PFS than those with SD. rChoi and mChoi criteria best delineated the difference in PFS for patients with PR versus SD, without or combined with clinical criteria. CONCLUSION: For mRCC patients treated with pazopanib, OS and PFS for PR and SD groups were best predicted by rChoi and mChoi criteria, without or combined with clinical risk factors. 10% threshold criteria also predicted OS and PFS, whereas RECIST did so only in a limited number of patients.

Prospective Phase 2 Trial of Permanent Seed Implantation Prostate Brachytherapy for Intermediate-Risk Localized Prostate Cancer: Efficacy, Toxicity, and Quality of Life Outcomes.

PURPOSE: To report the efficacy, physician-reported toxicity, and patient-reported outcomes of men with intermediate-risk prostate cancer after brachytherapy in a prospective phase 2 trial. METHODS AND MATERIALS: This prospective phase 2 trial involved 300 patients with previously untreated prostate cancer treated from 2006 through 2013. Eligible patients had ≤cT2b (T3 excluded according to magnetic resonance imaging), Gleason score (GS) 6 with prostate-specific antigen (PSA) level 10-15 ng/mL, or GS 7 with PSA <10 ng/mL, and were treated with prostate brachytherapy (without hormonal therapy). RESULTS: Median patient age was 64.9 years; 3.7% had GS 6, 78.7% had GS 7 (3+4), and 17.7% had GS 7 (4+3). Median follow-up time was 5.1 years. Median PSA at 5 years was 0.01 ng/mL (range, 0-6.0 ng/mL). Ten biochemical failures occurred, for a 5-year freedom from biochemical failure rate of 97.3% (95% confidence interval [CI], 95.1-99.5), and 16 patients died, only 1 from prostate cancer, for 5-year rates of overall and biochemical progression-free survival of 94.9% (95% CI, 92.1-97.9) and 92.7% (95% CI, 89.3-96.2%). Four patients had late grade 3 genitourinary toxicity, and 2 patients had late grade 3 rectal toxicity; no grade 4 or 5 toxicity was observed. Rates of "moderate or big problems" at 4 years were 7.4% for urinary (vs 0.4% at baseline), 2.9% bowel (vs 0.4%), and 29.7% sexual function (vs 19.7%). Most men were "satisfied or extremely satisfied" (91% at 2 years after treatment and 93% at 4 years). CONCLUSIONS: Brachytherapy monotherapy is safe and effective and leads to good quality of life for some men with localized intermediate-risk prostate cancer.

Comparison of early radiological predictors of outcome in patients with colorectal cancer with unresectable hepatic metastases treated with bevacizumab.

OBJECTIVE: The purpose was to validate the prognostic value of an early optimal morphological response on CT in patients treated with bevacizumab-containing chemotherapy for unresectable colorectal cancer liver metastases (CLM). It also evaluated the prognostic value of size-based criteria and the association of optimal morphological response with the receipt of bevacizumab. DESIGN: 141 patients treated first using bevacizumab and 142 patients from a randomised study evaluating the addition of bevacizumab to oxaliplatin-based chemotherapy were retrospectively analysed. Radiologists evaluated pretreatment and restaging CT scans using morphological response criteria. Responses were also assessed with size-based criteria: Response Evaluation Criteria in Solid Tumors (RECIST), early tumour shrinkage (ETS) and deepness of response (DpR). The ability of each criterion to predict progression-free survival (PFS), overall survival (OS) and postprogression survival (PPS) was determined using a univariate Cox proportional hazards model. RESULTS: In both populations, median PFS was significantly longer for patients achieving an optimal morphological response (10.4 vs 6.8 months, p=0.03; and 8.3 vs 4.9 months, p<00001, respectively). Neither RECIST nor ETS responses were associated with a prolonged PFS. Median OS was longer for those with an optimal morphological response but only at second restaging in the first population (n=141, 20.8 vs 12.3 months, p=0.002). DpR but not optimal morphological response was associated with PPS. In the randomised study, an optimal morphological response was 6.2 times more likely among patients receiving bevacizumab (p<0.0001). CONCLUSION: In patients with unresectable CLM, early morphological response may be a better predictor of PFS than size-based response. The addition of bevacizumab improves morphological response rate.

Alternative Response Criteria and Clinical Risk Factors for Assessing Tumor Response in Patients With Metastatic Renal Cell Carcinoma Who Are Receiving Salvage Therapy.

OBJECTIVE: The purpose of this study is to compare the prognostic value of various solid tumor response criteria as well as the additive value of clinical risk factors in patients with advanced renal cell carcinoma (RCC). MATERIALS AND METHODS: Two sets of CT scans (pretreatment scans and scans obtained 1-3.5 months after treatment) were reviewed for 57 patients with metastatic RCC treated with pazopanib in the salvage setting. Tumor response on the posttherapy scan was evaluated using Response Evaluation Criteria in Solid Tumors (RECIST) and Choi, modified Choi (mChoi), MASS (Morphology, Attenuation, Size, and Structure), and 10% threshold criteria. In addition, combined Memorial Sloan-Kettering Cancer Center (MSKCC) risk factors plus imaging criteria were used to define response groups. Response evaluations using these criteria were correlated with overall survival (OS) and progression-free survival (PFS), with use of the log-rank test. RESULTS: Patients classified as having progressive disease (PD) on the basis of RECIST, mChoi, and MASS criteria had a significantly worse OS than patients with stable disease (SD) and partial response (PR). With the addition of MSKCC risk factors, all groups with PD defined by combined criteria had significantly worse OS. For 37 patients with no or one MSKCC risk factor, response groups defined by Choi, mChoi, MASS, and 10% threshold criteria did not differ in PFS or OS. However, among 20 patients with two to three MSKCC risk factors, those classified as having PR had longer PFS than did those with SD and had longer OS than did those with PD. CONCLUSION: For patients with advanced RCC for which prior therapies have failed, the prognostic value of various imaging-based tumor response criteria differs on the basis of the MSKCC clinical risk status.

Using MRI to non-invasively and accurately quantify preoperative hepatic steatosis.

BACKGROUND: The obesity epidemic has significantly increased the incidence and severity of hepatic steatosis in liver surgery patients and liver donors, potentially impacting postoperative liver regeneration and function. Development of a non-invasive means to quantify hepatic steatosis would facilitate selection of candidates for liver resection and transplant donation. METHODS: An IRB-approved protocol prospectively enrolled 28 patients with liver tumors requiring hepatic resection. In all patients, fast dual-echo gradient-echo MR images were acquired using 2-Point Dixon technique in 2D and 3D. The degree of steatosis was quantified by percent fat fraction (%FF) from in- and out-of-phase, and water-only and fat-only images. The technique-specific %FFs were compared to intraoperative and histopathological findings. RESULTS: For patients with >30% steatosis by histology, the mean %FF was 22% (SD ± 5.2%) compared to a mean %FF of 5.0% (SD ± 2.1%, p = 0.0001) in patients with <30% steatosis. Using scaled values for the MR-calculated %FF, all patients with >30% pathologic steatosis could be identified preoperatively. CONCLUSIONS: Quantitative MRI identified patients with clinically-relevant steatosis with 100% accuracy. These findings could have significant impact on the management of liver resection patients and transplant donors.

Clinical characteristics and treatment outcome in a large multicentre observational cohort of PDGFRA exon 18 mutated gastrointestinal stromal tumour patients.

PURPOSE: Patients, platelet-derived growth factor receptor alpha (PDGFRA) D842V-mutated gastrointestinal stromal tumours (GISTs) are known for their insensitivity to imatinib. However, in clinical practice responses have been observed in some patients. We describe the natural history and treatment outcomes in a cohort of PDGFRA exon 18 mutated GIST patients. PATIENTS AND METHODS: A retrospective cohort study was conducted in PDGFRA exon 18 mutation GIST patients treated in six expert centres in the Netherlands and the United States. Two independent radiologists assessed radiological response to imatinib according to Choi's criteria in all patients with measurable disease treated with imatinib in neo-adjuvant or palliative intent. RESULTS: Seventy-one patients with PDGFRA exon 18 mutation were identified of whom 48 patients (69%) had a D842V mutation. Twenty-two (45.8%) D842V-mutated GIST patients received imatinib treatment, 16 had measurable disease. Fourteen out of the 23 (60.9%) patients with non-D842V mutations received imatinib treatment, eight had measurable disease. Two out of 16 (12.5%) D842V-mutated GIST patients had partial response, 3 patients (18.8%) had stable disease and 9 patients (56.3%) had progressive disease as best response. Two patients did not have follow-up computed tomography scans to assess response. Six out of 8 (75%) patients with non-D842V exon 18 mutations had partial response and two (25%) had stable disease as best response. CONCLUSION: Patients with D842V-mutated GISTs can occasionally respond to imatinib. In the absence of better therapeutic options, imatinib should therefore not be universally withheld in patients with this mutation.

NSCLC tumor shrinkage prediction using quantitative image features.

The objective of this study was to develop a quantitative image feature model to predict non-small cell lung cancer (NSCLC) volume shrinkage from pre-treatment CT images. 64 stage II-IIIB NSCLC patients with similar treatments were all imaged using the same CT scanner and protocol. For each patient, the planning gross tumor volume (GTV) was deformed onto the week 6 treatment image, and tumor shrinkage was quantified as the deformed GTV volume divided by the planning GTV volume. Geometric, intensity histogram, absolute gradient image, co-occurrence matrix, and run-length matrix image features were extracted from each planning GTV. Prediction models were generated using principal component regression with simulated annealing subset selection. Performance was quantified using the mean squared error (MSE) between the predicted and observed tumor shrinkages. Permutation tests were used to validate the results. The optimal prediction model gave a strong correlation between the observed and predicted tumor shrinkages with r=0.81 and MSE=8.60×10(-3). Compared to predictions based on the mean population shrinkage this resulted in a 2.92 fold reduction in MSE. In conclusion, this study indicated that quantitative image features extracted from existing pre-treatment CT images can successfully predict tumor shrinkage and provide additional information for clinical decisions regarding patient risk stratification, treatment, and prognosis.

Utility of preoperative ferumoxtran-10 MRI to evaluate retroperitoneal lymph node metastasis in advanced cervical cancer: Results of ACRIN 6671/GOG 0233.

RATIONALE AND OBJECTIVES: To assess if ferumoxtran-10 (f-10) improves accuracy of MRI to detect lymph node (LN) metastasis in advanced cervical cancer. MATERIALS AND METHODS: F-10 MRI component of an IRB approved HIPAA compliant ACRIN/GOG trial was analyzed. Patients underwent f-10 MRI followed by extra-peritoneal or laparoscopic pelvic and abdominal lymphadenectomy. F-10-sensitive sequences were T2* GRE sequences with TE of 12 and 21. Seven independent blinded readers reviewed f-10-insensitive sequences and all sequences in different sessions. Region correlations were performed between pathology and MRI for eight abdomen and pelvis regions. Sensitivity and specificity were calculated at participant level. Reference standard is based on pathology result of surgically removed LNs. RESULTS: Among 43 women enrolled in the trial between September 2007 and November 2009, 33 women (mean age 49 ±11 years old) with advanced cervical cancer (12 IB2, 3 IIA, 15 IIB and 3 IIIB, 29 squamous cell carcinomas, 32 grade 2 or 3) were evaluable. Based on histopathology, LN metastasis was 39% in abdomen and 70% in pelvis. Sensitivity of all sequence review in pelvis, abdomen, and combined were 83%, 60%, and 86%, compared with 78%, 54%, and 80% for f-10 insensitive sequences (P: 0.24, 0.44 and 0.14, respectively). Mean diameter of the largest positive focus on histopathology was 13.7 mm in abdomen and 18.8 mm in pelvis (P = 0.018). Specificities of all sequence review in pelvis, abdomen, and combined were 48%, 75%, and 43%, compared with 75%, 83%, and 73% (P: 0.003, 0.14, 0.002 respectively) for f-10 insensitive sequences. CONCLUSION: Addition of f-10 increased MRI sensitivity to detect LN metastasis in advanced cervical cancer. Increased sensitivity did not reach statistical significance and was at the expense of lower specificity.

Local recurrence map to guide target volume delineation after radical prostatectomy.

PURPOSE: To describe the various anatomic locations of recurrent disease, in a cohort of men with radiographically visualized, biopsy-proven recurrent prostate cancer after radical prostatectomy (RP), in order to help guide contouring of the prostatic fossa clinical target volume (PF-CTV) when no gross recurrence is visible or when magnetic resonance imaging (MRI) is not used. METHODS AND MATERIALS: Ten representative patients with MRI-detected, biopsy-proven local recurrences of prostate adenocarcinoma after RP were selected. Areas of recurrence were delineated on individual MRI images, and then mapped onto axial and sagittal "template" MRI images to compositely demonstrate the documented areas of recurrence. Coverage of these anatomic areas of recurrence was then evaluated by applying Radiation Therapy Oncology Group (RTOG)-consensus PF-CTV contours to a postoperative computed tomographic template. RESULTS: The median age at the time of RP was 61 years (range, 50-73). In the superoinferior direction, recurrences ranged from the superior retrovesical region, to the inferior retrovesical region, to the posterior anastomosis, and as inferiorly as the posterior urogenital diaphragm. In the anteroposterior direction, the areas of recurrence ranged from involving the posterior bladder wall anteriorly to invading the rectum posteriorly. Recurrences were found at the center, right, and left of the prostate and seminal vesicle fossa. When target volumes were delineated using RTOG-defined consensus PF-CTV contours, coverage was marginal on recurrences in the posterolateral aspects of the CTV near the rectum and mesorectal fascia and lacking on recurrences occurring inferiorly at the posterior urogenital diaphragm. CONCLUSIONS: Our findings describe the variation in location of prostate cancer recurrences and can be used to improve target definition in conformal radiation therapy in the postoperative adjuvant or salvage setting. RTOG-consensus contours for the PF-CTV should be applied carefully, with potential modifications in the posterolateral and inferior aspects.

Technical challenges in 3 T magnetic resonance spectroscopic imaging of the prostate-A single-institution experience.

The magnetic resonance spectroscopic imaging (MRSI) is the only technique that is currently available in the clinical practice to provide the metabolic status of prostate tissue at the cellular level with a great potential to improve the clinical patient care. Increasing the field strength from 1.5 to 3 T can theoretically provide proportionately higher signal-to-noise ratio (SNR) and improve spectral separation between prostatic metabolite peaks. The technique, however, has been limited to a few academic institutions that are equipped with a team of experts primarily due to due to serious technical challenges in optimizing the spectral quality. High quality shimming is key to the successful MRSI acquisition. Without optimization of the increased field inhomogeneity and radiofrequency (RF) dielectric effect at 3 T, the spectral peak broadening and residual signal from the periprostatic fat tissue may render the overall spectra non-diagnostic. The purpose of this technical note is to present the practical steps of successful acquisition of 3 T MRSI and to address several important technical challenges in minimizing the effect of the increased magnetic field and RF field inhomogeneity in order to obtain highest possible spectral quality based on our initial experience in using 3 T MRSI prototype software.

Optimization of MR imaging for pretreatment evaluation of patients with endometrial and cervical cancer.

Endometrial and cervical cancer are the most common gynecologic malignancies in the world. Accurate staging of cervical and endometrial cancer is essential to determine the correct treatment approach. The current International Federation of Gynecology and Obstetrics (FIGO) staging system does not include modern imaging modalities. However, magnetic resonance (MR) imaging has proved to be the most accurate noninvasive modality for staging endometrial and cervical carcinomas and often helps with risk stratification and making treatment decisions. Multiparametric MR imaging is increasingly being used to evaluate the female pelvis, an approach that combines anatomic T2-weighted imaging with functional imaging (ie, dynamic contrast material-enhanced and diffusion-weighted imaging). MR imaging helps guide treatment decisions by depicting the depth of myometrial invasion and cervical stromal involvement in patients with endometrial cancer and tumor size and parametrial invasion in those with cervical cancer. However, its accuracy for local staging depends on technique and image quality, namely thin-section high-resolution multiplanar T2-weighted imaging with simple modifications, such as double oblique T2-weighting supplemented by diffusion weighting and contrast enhancement.

High quality machine-robust image features: identification in nonsmall cell lung cancer computed tomography images.

PURPOSE: For nonsmall cell lung cancer (NSCLC) patients, quantitative image features extracted from computed tomography (CT) images can be used to improve tumor diagnosis, staging, and response assessment. For these findings to be clinically applied, image features need to have high intra and intermachine reproducibility. The objective of this study is to identify CT image features that are reproducible, nonredundant, and informative across multiple machines. METHODS: Noncontrast-enhanced, test-retest CT image pairs were obtained from 56 NSCLC patients imaged on three CT machines from two institutions. Two machines ("M1" and "M2") used cine 4D-CT and one machine ("M3") used breath-hold helical 3D-CT. Gross tumor volumes (GTVs) were semiautonomously segmented then pruned by removing voxels with CT numbers less than a prescribed Hounsfield unit (HU) cutoff. Three hundred and twenty eight quantitative image features were extracted from each pruned GTV based on its geometry, intensity histogram, absolute gradient image, co-occurrence matrix, and run-length matrix. For each machine, features with concordance correlation coefficient values greater than 0.90 were considered reproducible. The Dice similarity coefficient (DSC) and the Jaccard index (JI) were used to quantify reproducible feature set agreement between machines. Multimachine reproducible feature sets were created by taking the intersection of individual machine reproducible feature sets. Redundant features were removed through hierarchical clustering based on the average correlation between features across multiple machines. RESULTS: For all image types, GTV pruning was found to negatively affect reproducibility (reported results use no HU cutoff). The reproducible feature percentage was highest for average images (M1 = 90.5%, M2 = 94.5%, M1∩M2 = 86.3%), intermediate for end-exhale images (M1 = 75.0%, M2 = 71.0%, M1∩M2 = 52.1%), and lowest for breath-hold images (M3 = 61.0%). Between M1 and M2, the reproducible feature sets generated from end-exhale images were relatively machine-sensitive (DSC = 0.71, JI = 0.55), and the reproducible feature sets generated from average images were relatively machine-insensitive (DSC = 0.90, JI = 0.87). Histograms of feature pair correlation distances indicated that feature redundancy was machine-sensitive and image type sensitive. After hierarchical clustering, 38 features, 28 features, and 33 features were found to be reproducible and nonredundant for M1∩M2 (average images), M1∩M2 (end-exhale images), and M3, respectively. When blinded to the presence of test-retest images, hierarchical clustering showed that the selected features were informative by correctly pairing 55 out of 56 test-retest images using only their reproducible, nonredundant feature set values. CONCLUSIONS: Image feature reproducibility and redundancy depended on both the CT machine and the CT image type. For each image type, the authors found a set of cross-machine reproducible, nonredundant, and informative image features that would be useful for future image-based models. Compared to end-exhale 4D-CT and breath-hold 3D-CT, average 4D-CT derived image features showed superior multimachine reproducibility and are the best candidates for clinical correlation.

Intrabiliary growth of colorectal liver metastasis: spectrum of imaging findings and implications for surgical management.

OBJECTIVE: The propensity for colorectal liver metastasis to invade the biliary tree is increasingly recognized, placing particular emphasis on the risk of postoperative recurrence. This article illustrates the spectrum of imaging findings when colorectal metastasis invades the biliary tree. CONCLUSION: Knowledge of the imaging features of intrabiliary invasion by colorectal liver metastasis improves the quality of preoperative staging and is crucial in an era in which nonanatomic wedge resection and radiofrequency ablation are routinely performed.