Complete Imaging Response Research Articles

Treatment outcomes of the KEYNOTE-522 regimen in an ethnically diverse patient population: A real world experience.

e12663 Background: Pembrolizumab (pembro) in combination with neoadjuvant chemotherapy (NACT) became standard of care for high risk, early stage TNBC on July 26, 2021, as a result of the KEYNOTE-522 trial. Black women are disproportionately affected by TNBC with more advanced stage at diagnosis, however the KEYNOTE-522 did not collect data on race. This retrospective review evaluates response to pembro plus NACT in a racially diverse population to assess the generalizability of the trial findings to potentially under-represented patient populations. Methods: This is a single center, retrospective review of patients with stage II/III TNBC diagnosed between 08/2020 to 08/2023, treated with pembro plus NACT at Maimonides Medical Center, a safety-net hospital in Brooklyn, New York serving a diverse patient population. Exclusion criteria included age < 18 years, ER/PR/Her2 positivity, NACT without pembrolizumab and unreported race. Data were collected from electronic health records and analyzed using SPSS Statistics. Results: 50 patients met inclusion criteria, among whom 40 patients had complete information available for review. 52.5% (95% CI: 38% - 69%) of patients had a pCR. Nearly half of the patient population (47.5%) were African American. Subgroup analysis of ethnicity demonstrated a lower pCR amongst African American women, but this was not statistically significant (table). 5 patients had progression of disease with the development of distant metastasis (2 whilst on treatment and 3 following completion of therapy). 3 patients had grade 3/4 adverse events (pembro associated endocrine and cardiac dysfunction). Notably, lack of complete imaging response to treatment was significantly associated with lack of pCR (p=0.003). Conclusions: In this retrospective review of a racially diverse patient population, the pembrolizumab-NACT regimen was well tolerated with an acceptable side effect profile. While our rate of pCR is lower than the findings of the Keynote-522 trial; 52.5 % (95% CI: 38% - 69%) vs. 64.8% (95% CI: 59.9%-69.5%), our sample size is not large enough to detect a statistically significant difference. Sub-analysis of patient ethnicity demonstrated varying rates of pCR, however findings are limited by a small sample size. Additional data collection is in progress and future analysis will provide insight into a potential correlation between race and therapy response. [Table: see text]

Abstract PO2-22-06: MRI response Assessment of Single Fraction Pre-operative Stereotactic Radiotherapy: Preliminary results

Abstract Background: Pre-operative stereotactic breast irradiation (SPBI) improves targeting precision and has the potential to decrease treatment-related toxicity while downstaging or eliminating cancer. Accurate pCR prediction may allow omission of surgery. We are reporting initial interim results of the performance of multiparametric breast MRI in identifying pathologic response rate after single-fraction pre-operative SPBI in early stage estrogen receptor-positive (ER+), HER-2 negative breast cancer. Methods: In an ongoing single center prospective single-arm trial 22 patients with ER+/HER2-negative, cN0, unifocal, invasive breast cancer ≤3 cm underwent single-dose ablative SPBI, followed by definitive surgery per standard of care. Residual disease vs complete imaging response to SPBI was assessed on baseline and post-SPBI/pre-operative breast MRI. Pathologic response was categorized using MDACC Residual Cancer Burden (RCB) Categories. Wilcoxon rank sum test was used to assess the correlation of pathologic complete response (pCR) or RCB status on final path with MRI lesion size, volume, diffusion weighted imaging apparent diffusion coefficient (ADC) value, and when available, presence of residual enhancement on pre-operative MRI. MRI volume and ADC values were obtained using a dedicated CAD software. Area under the receiver operating Curve(AUC) was constructed to assess the diagnostic performance of pre-operative MRI on predicting pathologic response. Results Mean patient age was 64.9 (SD±7.3) years, tumor diameter 1.2(± 0.6) cm, pre-SPBI volume 6.4 ± 9.1 cm3, post SPBI volume 1.8 ± 5.6 cm3, ADC 0.91 ×10-3 mm2/s. At surgical pathology, 6(27.2%) achieved pCR/RCB-0, 9(41%) RCB-I, 7(31.8%) RCB-II. Mean baseline MRI size (1.2 ± 0.7 vs 1.3 ± 0.6, p=0.88), enhancement volumes (6.0±6.2 vs 7.9±9.9 cm3, p=0.59), DWI ADC values (1.1 ± 0.3 vs 0.9 ± 0.2 mm2/s, p-0.48) were not significantly different between tumors that showed pCR vs RCB I-II at surgical pathology. Time elapsed from SBRT to surgery were significantly longer in patients with pCR (264.3 ± 74.2 vs 183.7 ± 68.3 days, p=0.04) On pre-op MRI, mean enhancement volume was smaller in cancers that had pCR, however it did not reach significance (0.1 ± 0.1 vs 2.1 ± 6.0 cm3, p=0.2). Of 18 patients with available pre-operative MRI, residual enhancement was present in 7, of these 6/7(87%) had RCB I-II, and 1/7(13%) RCB-0 at surgical pathology. Conversely, in 11 patients with no residual enhancement on MRI, pathology showed pCR/RCB-0 in 5(45.5%), while 6(54.5%) had RCB I or II. Presence of residual enhancement on pre-operative MRI had an AUC of 0.68 (95%CI 0.43; 0.93, p=0.2) in predicting residual cancer after SPBI. Conclusion: Detecting residual enhancement on pre-operative MRI is a strong indicator of residual disease after SPBI, while lack of enhancement is not a reliable predictor of pCR. Our preliminary results do not indicate an association between baseline MRI enhancement volume, DWI ADC and pathologic response. Citation Format: Baṣak Dogan, Sunati Sahoo, Marilyn Leitch, Prasanna Alluri, Robert Timmerman, Deborah Farr, Asal Rahimi. MRI response Assessment of Single Fraction Pre-operative Stereotactic Radiotherapy: Preliminary results [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-22-06.

Evaluating persistent T1-weighted lesions without concurrent abnormal enhancement on breast MRI in neoadjuvant chemotherapy patients: implications for complete pathological response.

This study aims to determine whether persistent T1-weighted lesions signify a complete pathological response (pCR) in breast cancer patients treated with neoadjuvant chemotherapy and surgery, and to evaluate their correlation with imaging responses on MRI. A retrospective review was conducted on data from breast cancer patients treated between January 2011 and December 2018. Patients who underwent breast MRI and pre- and post-neoadjuvant chemotherapy followed by surgery were included. Those with distant metastasis, no planned surgery, pre-surgery radiation, ineligibility for neoadjuvant chemotherapy, or unavailable surgical pathology were excluded. Groups with and without persistent T1-weighted lesions were compared using the chi-square test for categorical variables and the Student t test or Wilcox rank sum test for continuous variables. Univariate logistic regression was used to evaluate the association of the final pathological response with the presence of T1-persistent lesion and other characteristics. Out of 319 patients, 294 met the inclusion criteria (breast cancer patients treated with neoadjuvant chemotherapy and subsequent surgery); 157 had persistent T1 lesions on post-chemotherapy MRI and 137 did not. A persistent T1 lesion indicated reduced likelihood of complete pathological response (14% vs. 39%, p < 0.001) and imaging response (69% vs. 93%, p < 0.001). Multivariable analysis confirmed these findings: OR 0.37 (95% CI 0.18-0.76), p = 0.007. No other characteristics correlated with T1 residual lesions. Persistent T1-weighted lesions without associated abnormal enhancement on post-treatment breast MRI correlate with lower complete pathological and imaging response rates. The study underscores the importance of persistent T1-weighted lesions on breast MRI as vital clinical markers, being inversely related to a complete pathological response following neoadjuvant chemotherapy; they should be a key factor in guiding post-neoadjuvant chemotherapy treatment decisions. • Persistent T1 lesions on post-chemotherapy breast MRI indicate a reduced likelihood of achieving a complete pathological response (14% vs. 39%, p < 0.001) and imaging response (69% vs. 93%, p < 0.001). • Through multivariable analysis, it was confirmed that the presence of a persistent T1 lesion on breast MRI post-chemotherapy is linked to a decreased likelihood of complete pathological response, with an odds ratio (OR) of 0.37 (95% CI 0.18-0.76; p = 0.007). • In addition to the convention of equating the absence of residual enhancement to complete imaging response, our results suggest that the presence or absence of residual T1 lesions should also be considered.

Large, multifocal or portal vein-invading hepatocellular carcinoma (HCC) downstaged by Y90 using personalized dosimetry: safety, pathological results and outcomes after surgery.

Transarterial radioembolization (TARE) has recently been recognized as a bridging/downstaging therapy to surgery for early hepatocellular carcinomas (HCCs) with high rates of complete pathological necrosis (CPN) on liver explants. In patients with portal vein tumoral thrombus (PVTT), multifocal or large tumors, TARE has mainly a palliative role and surgery remains controversial in this poor-prognosis population. Personalized dosimetry recently proved to outperform standard dosimetry used in prior negative Y90 randomized-controlled trials. In this retrospective study, we evaluated safety, radiological and pathological response and outcomes in HCC patients with PVTT, multifocal or large tumors, who underwent surgery after downstaging using TARE with Y90-loaded glass microspheres with personalized dosimetry. Between December 2015 and October 2021, 18 unresectable patients (14/18 with PVTT) had surgery (16 resections, 2 liver transplantations) 6.2 months (range, 2-14.6 months) after a single Y90 treatment. No 90-day mortality was reported. Objective modified response criteria in solid tumors (mRECIST) response were noted in all but one patient. Complete and extensive (50-99%) necrosis was observed in 36% and 45% of tumors, respectively. The post-treatment tumor-absorbed dose significantly differed depending on the extent of pathological necrosis (P=0.045). Median overall survival and progression-free survival (PFS) were respectively of 61.8 months [95% CI: 31.4 months-not reached (NR)] and 49.3 months (95% CI: 14 months-NR). PFS was longer in patients with complete imaging response [median NR (none recurred or died) vs. 21.5 months (95% CI: 10.1 months-NR), P<0.001] and in those with complete pathological response [median NR vs. 22.5 months (95% CI: 10.1 months-NR), P<0.001]. Y90 TARE using personalized dosimetry can provide high rates of imaging and pathological response in patients with PVTT, large or multifocal HCC. Subsequent surgery is safe and leads to outcomes far exceeding expectations in an otherwise poor prognosis population with no chance for cure. Clinical trial number: NCT05045573.

Abstract PD16-03: Use of post-neoadjuvant chemotherapy image-guided breast vacuum assisted biopsy to predict residual cancer in exceptional responders: A prospective cohort study

Abstract Background: Post-neoadjuvant chemotherapy (NAC) image-guided biopsy of the residual imaging abnormality/tumor bed is increasingly used to assess residual disease in the breast and potentially identify exceptional responders who may not require surgical intervention. Previous studies have shown variable results on the diagnostic performance of this technique. The aim of this analysis was to assess the accuracy of post-NAC, image-guided vacuum assisted biopsy (VAB) to predict residual disease in the breast using a standardized assessment protocol. The findings could help further support the optimal design of trials omitting surgery in selected patients. Methods: Prospective cohort study (BR154b) of consecutive patients with HER2 positive and triple negative (TN) invasive ductal carcinoma (IDC), treated with NAC, who underwent post-NAC VAB to aid surgical planning between 02/2018 and 06/2022 at one institution. Patients with complete/near complete imaging response (residual imaging abnormality ≤ 2cm) had a VAB to sample ≥ 90% of the breast residuum/tumor bed previously marked by clip insertion. Biopsy samples were defined as representative if pathology features suggestive of tumor bed or residual cancer were identified. Pathologic complete response (pCR) was defined as no residual invasive or in situ disease in the breast (ypT0). Diagnostic accuracy of VAB was calculated using final surgical pathology as the reference standard. Simple descriptive statistics were used. Results: A total of 54 women met the eligibility criteria and underwent post-NAC VAB. This was not representative in 3 cases and therefore 51 women were included in the analysis. Median age was 49 years [interquartile range (IQR): 43 – 61]. The majority of cancers were grade 3 (n=31) or grade 2 (n=19). Subtype distribution was 21 (41.2%) for hormone receptor (HR) positive/HER2 positive, 13 (25.5%) for HR negative/HER2 positive and 17 (33.3%) for TN IDC. There was associated DCIS at diagnosis in 37.3% of cases. The majority of the cancers at presentation were T2 (n=35, 68.6%) with a median tumor size on imaging of 28 mm (IQR: 28 – 43). There were associated microcalcifications in 29 cases (n=11 extending beyond the main tumor). Sixteen women presented with cN+ disease. On completion of NAC, 19 women had complete imaging response, while in the remaining the median size of the residual imaging abnormality was 12 mm (IQR: 9 – 16). A post-NAC VAB was performed with ultrasound or stereo-guidance in 48 and 3 cases respectively. The median size (gauze) of needle used was 10 (IQR: 10) and the median number of cores obtained was 8 (IQR: 6-8). In the surgical specimen, the overall breast pCR rate was 58.8% (52.4% for HR positive/HER2 positive, 76.9% for HR negative/HER2 positive and 52.9% for TN). The axillary pCR rate was 81.25%. The false negative rate (FNR) of post-NAC VAB was 4.76% (1/51, 95% CI: 0.12 – 23.82%). The sensitivity and specificity for residual disease were 95.24% (95% CI: 76.18 – 99.88) and 93.33% (95% CI: 77.93 – 99.18) respectively. The negative predictive value was 96.55% (95% CI 80.49 – 99.48) and the overall accuracy 94.12% (95% CI: 83.76 – 98.77). Conclusions: This analysis suggests that a standardized assessment protocol using image-guided VAB in patients with HER2 positive or TN IDC and exceptional response to NAC (residual imaging abnormality/tumor bed measuring ≤ 2 cm) aiming to sample ≥ 90% of the breast residuum allows reliable prediction of residual disease and breast pCR with a FNR &amp;lt; 5%. These results further support the optimal design of de-escalation trials in NAC exceptional responders testing the safety of omitting surgery. Citation Format: Marios Konstantinos Tasoulis, Romney Pope, Tanja Gagliardi, Ashutosh Nerurkar, Alicia F. Okines, Nicholas Turner, Fiona MacNeill. Use of post-neoadjuvant chemotherapy image-guided breast vacuum assisted biopsy to predict residual cancer in exceptional responders: A prospective cohort study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD16-03.

Abstract No. 194 Tumor response after ablative Y-90 transarterial radioembolization for hepatocellular carcinoma based on post-hoc voxel-based dosimetry

Dosimetry for glass trans-arterial radioembolization (TARE) is commonly calculated via a uniform activity distribution model. Recent studies have demonstrated improved tumor response with increased dose to perfused area though no tumor dose threshold is established. This study evaluates dose to tumor and treatment response (mRECIST and LI-RADS criteria) after TARE for early-stage hepatocellular carcinoma (HCC) to determine a threshold tumor dose to predict a complete imaging response.

Sustained Residual Disease Negativity Assessed By Diffusion-Weighted Whole-Body MRI (DW-MRI) Has Strong Predictive Relevance for Survival in Newly Diagnosed Multiple Myeloma Patients on Maintenance Therapy after Autologous Stem Cell Transplantation (ASCT)

Sustained Residual Disease Negativity Assessed By Diffusion-Weighted Whole-Body MRI (DW-MRI) Has Strong Predictive Relevance for Survival in Newly Diagnosed Multiple Myeloma Patients on Maintenance Therapy after Autologous Stem Cell Transplantation (ASCT)

Predictive role of diffusion-weighted whole-body MRI (DW-MRI) imaging response according to MY-RADS criteria after autologous stem cell transplantation in patients with multiple myeloma and combined evaluation with MRD assessment by flow cytometry.

BackgroundDiffusion‐weighted whole‐body MRI (DW‐MRI) is increasingly used in the management of multiple myeloma (MM) patients, but data regarding the prognostic role of DW‐MRI imaging response after treatment are lacking. The Myeloma Response Assessment and Diagnosis System (MY‐RADS) imaging recommendations recently proposed the criteria for response assessment category (RAC) with a 5‐point scale in order to standardize response assessment after therapy, but this score still needs to be validated.MethodsWe investigated the prognostic role of RAC criteria in 64 newly diagnosed MM patients after autologous stem cell transplantation (ASCT), and we combined the results of MY‐RADS with those of minimal residual disease (MRD) assessment by multiparametric flow cytometry (MFC).ResultsSuperior post‐ASCT PFS and OS were observed in patients with complete imaging response (RAC1), with respect to patients with imaging residual disease (RAC≥2): median PFS not reached (NR) versus 26.5 months, p = 0.0047, HR 0.28 (95% CI: 0.12–0.68); 3‐year post‐ASCT OS 92% versus 69% for RAC1 versus RAC ≥2, respectively, p = 0.047, HR 0.24 (95% CI: 0.06–0.99). Combining MRD and imaging improved prediction of outcome, with double‐negative and double‐positive features defining groups with excellent and dismal PFS, respectively (PFS NR vs. 10.6 months); p = 0.001, HR 0.07 (95%CI: 0.01–0.36).ConclusionThe present study supports the applicability of MY‐RADS recommendations after ASCT; RAC criteria were able to independently stratify patients and to better predict their prognosis and the combined use of DW‐MRI with MFC allowed a more precise evaluation of MRD.

External Validation of Diffusion Weighted Whole Body MRI (DW-MRI) Response Assessment Category (RAC) Criteria Proposed By the Myeloma Response Assessment and Diagnosis System (MY-RADS) Imaging Recommendations: Prognostic Role of Imaging Response after Transplant in Multiple Myeloma and Comparison with MRD Evaluation By Flow Cytometry

External Validation of Diffusion Weighted Whole Body MRI (DW-MRI) Response Assessment Category (RAC) Criteria Proposed By the Myeloma Response Assessment and Diagnosis System (MY-RADS) Imaging Recommendations: Prognostic Role of Imaging Response after Transplant in Multiple Myeloma and Comparison with MRD Evaluation By Flow Cytometry

Delayed response to proton beam treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has become one of the leading causes of cancer death worldwide. There has been anecdotal report regarding the effectiveness of proton beam treatment for HCC. In this pre-clinical investigation, the woodchuck model of viral hepatitis infection-induced HCC was used for proton beam treatment experiment. The radiopaque fiducial markers that are biodegradable were injected around the tumor under ultrasound guidance to facilitate positioning in sequential treatments. An α cradle mode was used to ensure reproducibility of animal positioning on the treatment couch. A CT scan was performed first for contouring by a radiation oncologist. The CT data set with contours was then exported for dose planning. Three fractionations, each 750 CcGyE, were applied every other day with a Mevion S250 passive scattering proton therapy system. Multiphase contrast-enhanced CT scans were performed after the treatment and at later times for follow-ups. 3 weeks post-treatment, shrinking of the HCC nodule was detected and constituted to a partial response (30% reduction along the long axis). By week nine after treatment, the nodule disappeared during the arterial phase of multiphase contrast-enhanced CT scan. Pathological evaluation corroborated with this imaging response. A delayed, but complete imaging response to proton beam treatment applied to HCC was achieved with this unique and clinically relevant animal model of HCC.

Safety and initial efficacy of radiation segmentectomy for the treatment of hepatic metastases​.

Hepatic metastatectomy and ablation are associated with prolonged survival, but not all lesions are anatomically amenable to these therapies. We evaluated safety and initial efficacy of segmental ablative transarterial radioembolization, or radiation segmentectomy (RS), as a treatment for hepatic metastases. A single institution retrospective analysis was performed of patients with hepatic metastases, determined unamenable to resection by a multidisciplinary tumor board, treated with RS from 2015-2017. Safety parameters evaluated were pre and post procedure liver chemistry, MELD score, ALBI grade, platelet count, and adverse events using both Common Terminology Criteria for Adverse Events (CTCAE) v 4.0 and Clavien Dindo (CD) classifications. Initial efficacy was evaluated using RECIST, mRECIST, and PERCIST criteria. Ten patients underwent between 1-3 RS treatments. There was no clinical treatment toxicity or significant post-treatment change in liver chemistry, MELD, or ALBI score. One patient had a CTCAE Grade 1/CD Grade 1 adverse event. All patients showed partial or complete imaging response at initial assessment (1-3 months). Seven patients demonstrated disease control at a mean of 7.1 months post treatment. Three patients developed out of field disease progression. One RS was technically unsuccessful. Early evaluation of segmental radioembolization suggests a safe treatment option for select patients with hepatic metastases. Initial efficacy as definitive radiotherapy with minimal toxicity is promising in anatomic locations unamenable to resection or alternative means of ablation.

Abstract No. 518 Factors associated with recurrence of hepatocellular carcinoma with complete imaging response after treatment with transarterial chemoembolization

To identify factors affecting tumor recurrence in patients with unresectable hepatocellular carcinoma (HCC) treated with transarterial chemoembolization (TACE), who present complete imaging response (CIR) postprocedure. Retrospective single-center study. Consecutive patients with unresectable HCC, treated with TACE from January 2005 to December 2016, who presented CIR in the first postprocedure imaging control, were included. Patients who received contemporary adjuvant treatment (radiofrequency, microwave or alcoholization) or patients without imaging follow-up were excluded. CIR was defined as absence of contrast-enhancement of the treated lesion in arterial phase. As local recurrence were considered: detection of contrast-enhancement in the treated lesions in arterial phase, washout of the treated lesions in portal-venous phase, or an increase in lesion size after CIR. Age, gender, etiology of chronic liver damage, Child-Pugh classification, MELD-Na score, number, size and location of HCC, and chemoembolization technique were analyzed. Chi-square test was used to compare qualitative variables, and Wilcoxon or t-student test for the quantitative variables. Multiple logistic regression analysis was performed to study factors that modify tumor recurrence. A p-value less than 0.05 was considered statistically significant. From a total of 206 HCC in 148 patients treated with TACE during the study period, 71 tumors were analyzed after applying the inclusion/exclusion criteria. The mean follow-up was 9.7 months (range, 1-36 months). Tumor recurrence at 6-, 12- and 24-months was 21%, 32% and 42%, respectively. In multivariate analysis, tumor size ≥ 3 cm was the only factor that demonstrated a significant association with tumor recurrence, with OR 6.41 (95% CI: 1.71-23.97) (p = 0.006). Recurrence of HCC with complete imaging response after treatment with TACE is common, a result that is consistent with previous reports. Tumor size ≥ 3 cm is significantly associated with an increased risk of tumor recurrence.

Abstract P4-04-19: Endocrine medical treatment in breast cancer, is that enough?

Abstract Endocrine treatment has been in the management of hormone receptor breast cancer for a few decades, but never as the first line of treatment. Now in the biomolecular era, we are able to select patients where endocrine treatment can be considered the first line of treatment. Methods: During the months of May 2011 until June 2017, patients with ductal/lobular, in-situ and invasive cancer were treated medically with endocrine treatment as first choice of treatment (Tamoxifen/AI), due to medical morbidity or as requested by patients. The use of biomolecular assays helped to support the treatment decision. The infrastructure of ABC as a comprehensive center with all the modalities for diagnostic and interventional breast imaging center allow us to do all the follow up with the same health professionals. The assessments of the follow-ups were based on clinical, imaging (MRI, ultrasound and mammogram), and pathological responses. We use the term "complete clinical response" on patients where the clinical history and the physical examination demonstrate complete improvement of the breast cancer. "Complete imaging response" is referred to those patients that before treatment had a breast MRI with enhancement lesions and in the follow-ups show no more enhancements. "Complete pathological response" refers to patients which had no residual cancer on the surgical specimen. Results: We followed a total of 32 patients for an average period of 20.12 months (range=2-63 months), and an average age of 69.69 (range=45-86). Twenty-six of these patients (81.2 %) had Invasive Ductal Carcinoma, 6 patients (18.7%)had DCIS, 23 of the patients (71.88%), were only treated with endocrine treatment.Nine patients (28.13%) were treated with endocrine therapy plus surgery. The decision for surgery was a personal request of the patient, not a failure of the endocrine treatment. The 32 patients (100%) had a complete clinical response. Twenty-five patients (78.13%) presented a complete imaging response.From the patients who had surgery,1 patient (11.11%) presented a complete pathological response, 6 patients (66.67%) presented down staging of the tumor, and 2 patients (22.22%) presented no change. Twenty-nineof the 32 patients (90.63%) were able to obtain the recurrence score by Twenty-one Genes.Twenty-four of those had a low recurrence score, 4 had an intermediate score, and 1 patient had a high recurrence score. Discussion: Even though this is a small group of patients, there was no failure of treatment, mortality or progress of the disease. It demonstrated that, on selective patients, the effectiveness of endocrine treatment is possible, and can be used as the first line treatment. The selection of those patients was supported with the use of the 21 genes. Conclusion:Now days endocrine treatment, based on clinical and biomolecular assays, can be considered safe to use as first line of treatment for invasive and non-invasive breast cancer for those patients that refuse surgery or chemotherapy. Citation Format: Rosario V, Torres C, Santiago CP. Endocrine medical treatment in breast cancer, is that enough? [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-04-19.

Image-guided tandem and cylinder brachytherapy as monotherapy for definitive treatment of inoperable endometrial carcinoma.

Management of endometrial cancer consists of surgical staging with adjuvant therapy guided by risk factors, though some women cannot undergo surgery due to comorbidities. We present a series of women treated with definitive high-dose rate image-guided tandem and cylinder brachytherapy (HDR-IGBT) alone. Patients with grade 1-2, clinical stage I endometrial adenocarcinoma, <50% myometrial invasion, and tumor≤2cm were reviewed. Definitive treatment consisted of 5-6 fractions HDR-IGBT alone with CT- or MRI-based planning. Local-regional control (LRC) was defined as complete imaging response and/or cessation of vaginal bleeding. From 2007 to 2016, 45 patients were treated to a median dose of 37.5Gy. The median gross tumor volume (GTV) and clinical target volume (CTV) were 5.9cm3 (range, 0.7-18.7) and 80.9cm3 (17.2-159.0), respectively. The median cumulative dose to 90% (D90) of the GTV was 132.8Gy (76.5-295.6) equivalent 2Gy dose, and the median CTV D90 was 49.7Gy (34.5-57.2). Median follow-up among living patients was 18.6months (3.0-64.3). Cessation of vaginal bleeding occurred in 98%. Among those with post-treatment MRI (64%), complete radiographic response was demonstrated in 90%. The 2-year LRC, cancer-specific survival, and overall survival rates were 90%, 86%, and 97%, respectively. No grade 3+ acute or late toxicity was observed. HDR-IGBT alone for treatment of early-stage, medically inoperable endometrial cancer is feasible with excellent response rates and clinical results. This approach also allows sparing of critical organs and ensures target coverage, which contributed to the low toxicity rate and high LRC in comparison with 2D point-based series.

Superselective Yttrium-90 Radioembolization for Hepatocellular Carcinoma Yields High Response Rates with Minimal Toxicity

PurposeTo assess the safety and efficacy of yttrium-90 (90Y) radioembolization when performed in a superselective fashion for patients with unresectable hepatocellular carcinoma (HCC). Materials and MethodsThis retrospective study included 20 patients with unresectable HCC. Median Model for End-Stage Liver Disease score was 10.5 (range, 6–25), with 8 of 20 patients (40%) classified Child-Pugh class B and 1 of 20 patients (5%) classified class C cirrhosis. Segmental tumor-associated portal vein thrombus was present in 12 patients (60%), and a transjugular intrahepatic portosystemic shunt was present in 4 patients (20%). Median tumor diameter was 3.9 cm (range, 2.5–7.1 cm). All patients underwent superselective 90Y radioembolization targeted to a single liver segment using glass microspheres. ResultsMedian dose to the treated segment was 254 Gy, and median dose to the tumor was 536 Gy. No grade 3–4 hepatotoxicity occurred. The most common clinical toxicities were fatigue (30%), abdominal pain (10%), and postembolization syndrome (10%). Follow-up imaging demonstrated complete European Association for the Study of the Liver response of the index tumor in 19 of 20 patients (95%) and stable disease in 1 of 20 patients (5%). In patients with complete response, local tumor recurrence rate was 5.3% (1 of 19 patients). Median time to progression was 319 days. Overall survival was 90% (18 of 20 patients) with a median follow-up period of 275 days (range, 32–677 d). ConclusionsWhen performed in a segmental fashion, 90Y radioembolization demonstrates high response rates and low local tumor recurrence rates. Complete imaging response can be achieved in patients with locally aggressive disease. This study demonstrates no clinically significant hepatotoxicity, despite moderate liver dysfunction in many patients.

Abstract P1-01-04: Nodal patterns of care in patients with invasive breast cancer treated with neoadjuvant systemic therapy: Results of a secondary analysis of TBCRC 017

Abstract Background: Neoadjuvant chemotherapy (NCT) to downstage locally advanced tumors and potentially allow breast conservation has increased. In parallel, the use of sentinel lymph node biopsy (SNB) and axillary node dissection has evolved. This analysis reports patterns of care for axillary evaluation at 8 NCI Comprehensive Cancer Centers in women receiving NCT. Methods: Between 2002 and 2010, 770 women were retrospectively identified as having received NCT, 758 of who had nodal imaging either before or after NCT. Clinical, pathologic, and treatment data were collected. Univariate and multivariate analyses of covariates associated with axillary management were performed using logistic regression (SAS 9.2, Proc Logistic). Results: Between 2002 and 2010, the odds of receiving a post-NCT SNB increased by 8% per year (p&amp;lt;0.001). Rates of post-NCT SNB were significantly different in only one of eight institutions (p&amp;lt;0.001), where pre-NCT nodal evaluation was made by SNB. The remainder of institutions used SNB following NCT. Of those who underwent post-NCT SNB, regardless of nodal status pre-NCT, 55% (171/314) had axillary lymph node dissection (ALND). Prior to NCT, 74% (564/758) of patients exhibited at least one abnormal lymph node on pretreatment imaging. Imaging modalities used pretreatment to assess axillary lymph nodes Suspicious Nodes N (%)Ultrasound24 (4.3)Ultrasound+MRI218 (38.7)Ultrasound +MRI+CT103 (18.3)Ultrasound+MRI+CT+PET39 (6.9)Ultrasound+MRI+PET9 (1.6)Ultrasound+CT12 (2.1)Ultrasound+CT+PET8 (1.4)Ultrasound+PET3 (0.5)MRI36 (6.4)MRI+CT58 (10.3)MRI+CT+PET21 (3.7)MRI+PET9 (1.6)CT18 (3.2)CT+PET3 (0.5)CT+PET3 (0.5)TOTAL564 (100) Of those, 52% (291/564) of the lymph nodes were sampled using fine needle aspiration (FNA) and 27% (149/564) were sampled with CNB. Odds of undergoing a core needle biopsy (CNB) at presentation for radiographically or clinically suspicious lymph nodes increased by 27% per year (p&amp;lt;0.001). 57% (322/564) of all sampled lymph nodes were positive for malignant cells by either FNA or CNB. Of those with confirmed positive nodes at diagnosis, 26% (83/322) had nodal sampling with SNB after NCT. Of the 462 patients with pretreatment MRI suggesting an abnormal lymph node, 155 (33.5%) had a complete imaging response in the lymph nodes by MRI. Of those patients 32% (49/155) had SNB as their initial axillary evaluation after NCT, of which 45% (22/49) of those exhibited persistently positive nodes and underwent completion axillary node dissection. Conclusions: Among a contemporary cohort of women receiving NCT, a significant trend was observed towards increased use of needle biopsy for patients with abnormal pretreatment nodal imaging at presentation and sentinel lymph node biopsy after NCT nodal evaluation. A trend was also observed over time towards greater use of post-NCT SNB in patients with confirmed pathologic positive nodes at presentation. These data demonstrate a trend towards less invasive assessment of suspicious lymph nodes both before and after NCT. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-01-04.

Safety and Efficacy of Drug-eluting Bead Chemoembolization for Hepatocellular Carcinoma: Comparison of Small-versus Medium-size Particles

PurposeTo compare safety and imaging response with 100–300 μm and 300–500 μm doxorubicin drug-eluting bead (DEBs) to determine optimal particle size for chemoembolization of hepatocellular carcinoma (HCC). Materials and MethodsDEB chemoembolization using 100–300 μm (n = 39) or 300–500 μm (n = 22) LC beads loaded with 50 mg of doxorubicin was performed in 61 patients with HCC. Patient age, sex, etiology of liver disease, degree of underlying liver disease, tumor burden, and performance status were similar between the groups. All treatments were performed in a single session and represented the patient’s first treatment. Toxicities and imaging response in a single index tumor were analyzed using World Health Organization (WHO) and European Association for the Study of the Liver (EASL) criteria. ResultsThere was a significantly lower incidence of postembolization syndrome and fatigue after treatment in the 100–300 μm group (8% and 36%) versus the 300–500 μm group (40% and 70%) (100–300 μm group, P = .011; 300–500 μm group, P = .025). Mean change in tumor size was similar between the two groups based on WHO and EASL criteria and similar rates of objective response, but there was a trend toward a higher incidence of EASL complete response with 100–300 μm beads versus 300–500 μm beads (59% vs 36%; P = .114). ConclusionsIn DEB chemoembolization for treatment of HCC, 100–300 μm doxorubicin DEBs are favored over 300–500 μm doxorubicin DEBs because of lower rates of toxicity after treatment and a trend toward more complete imaging response at initial follow-up.

Control of brain metastases using frameless image-guided radiosurgery

Radiosurgery is an important and well-accepted method in the management of brain metastases. Using conventional frame-based techniques, high lesional control rates are expected. The introduction of image-guided techniques allows for improved patient comfort and workflow. Some controversy exists as to the accuracy of imageguided techniques and consequently the impact they might have on control of brain metastases (as opposed to the level of control achieved with frame-based methods). The authors describe their initial 15-month experience with image-guided radiosurgery (IGRS) using Novalis with ExacTrac for management of brain metastases. The authors reviewed the cases of brain metastasis treated by means of IGRS in their tertiary regional radiation oncology service over a 15-month period. During the study period 54 patients (median age 57.9 years) harboring 108 metastases were treated with IGRS. The median time from cancer diagnosis to development of brain metastasis was 12 months (range 0-144 months). The median tumor volume was 0.98 cm(3) (range 0.03-19.07 cm(3)). The median prescribed dose was 18 Gy to the 80% isodose line (range 14-20 Gy). Lesions were followed with postradiosurgery MR imaging every 2-3 months following treatment. The median follow-up period was 9 months (range 0-20 months). Median actuarial survival was 8.6 months following IGRS. Eight patients with 18 lesions died within the first 2 months after the procedure, before scheduled follow-up imaging. Thus 90 lesions (in 46 patients) were followed up with imaging studies. Lesions that were unchanged or reduced in size were considered to be under control. The 6-month actuarial lesion control rate was 88%. Smaller lesions (< 1 cm(3)) had a statistically improved likelihood of complete imaging response (loss of all contrast-enhancement p = 0.01). Image-guided radiosurgical treatment of brain metastases resulted in high rates of tumor control comparable to control rates reported for frame-based methods. High control rates were seen for small lesions in which spatial precision in dose delivery is critical. These data suggests that in regard to lesion control, IGRS using Novalis with ExacTrac is equivalent to frame-based radiosurgery methods.