Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Recommendations for a standardised educational program in robot assisted gynaecological surgery: Consensus from the Society of European Robotic Gynaecological Surgery (SERGS)

BACKGROUND

The Society of European Robotic Gynaecological Surgery (SERGS) aims at developing a European consensus on core components of a curriculum for training and assessment in robot assisted gynaecological surgery.

METHODS

A Delphi process was initiated among a panel of 12 experts in robot assisted surgery invited through the SERGS. An online questionnaire survey was based on a literature search for standards in education in gynaecological robot assisted surgery. The survey was performed in three consecutive rounds to reach optimal consensus. The results of this survey were discussed by the panel and led to consensus recommendations on 39 issues, adhering to general principles of medical education.

RESULTS

On review there appeared to be no accredited training programs in Europe, and few in the USA. Recommendations for requirements of training centres, educational tools and assessment of proficiency varied widely. Stepwise and structured training together with validated assessment based on competencies rather than on volume emerged as prerequisites for adequate and safe learning. An appropriate educational environment and tools for training were defined. Although certification should be competence based, the panel recommended additional volume based criteria for both accreditation of training centres and certification of individual surgeons.

CONCLUSIONS

Consensus was reached on minimum criteria for training in robot assisted gynaecological surgery. To transfer results into clinical practice, experts recommended a curriculum and guidelines that have now been endorsed by SERGS to be used to establish training programmes for robot assisted surgery.

Abstract P2-14-12: Impact of the time interval between neoadjuvant chemotherapy and surgery in Latin-Americans breast cancer patients

Background: Few studies have evaluated the impact of the time interval between neoadjuvant chemotherapy (NAC) and surgery in breast cancer. In Latin America, where the vast majority of hospitals are oversaturated, it is important to define which patients to give priority and to be clear about ideal time or maximum to schedule surgery after NAC without altering the prognosis. The objective of this work is to establish the ideal time interval for post-neoadjuvant surgery and evaluate the impact on patient survival.

Methods: We reviewed the clinical histories of breast cancer with clinical stage II and III who received NAC between 2005 and 2014. Patients were divided into 3 groups according to the time interval to surgery: <4, 4-8 and >8 weeks. Overall survival (OS) and recurrence-free survival (RFS) were estimated using the Kaplan-Meier method, and comparisons of survival curves using the logrank or Breslow test, both globally and by molecular subtypes. The optimal time to surgery has been determined by the Cox model.

Results: During the study period, 583 patients who had post NA surgery before six months were registered. The median age was 49 years (range: 24-85), 82% had clinical stage III, 53% histological grade III, 32.7% were luminal A, 15.6% luminal B, 24.4% Her2 and 27.3% TN. According to the time interval to surgery, 67 (11.5%) patients had surgery before 4 weeks, 204 (35.0%) between 4 to 8 weeks, and 312 (53.5%) after 8 weeks. The groups do not present differences in relation to the clinical characteristics (p> 0.05). The median follow-up time was 4.8 years. The 5-year OS rate according to the time interval was 57.9, 61.5, and 62.7% (p = 0.581) and the RFS rate was 40.6, 52.3, and 51.1% (p = 0.411). No differences were found in the survival curves by molecular subtypes , except for luminal b like . In the multivariate analysis, the effect of the time interval to surgery was not significant in OS and RFS; however, the HR curve suggests that the appropriate cut-off point for surgical time would be 8 weeks.

Table 1:Time Interval :OS - RFS  RFS  OS  MEDIAN5 - yearsPMEDIAN5 - yearsPWeeks for NAC to Surgery      <4 weeks3.240.6 6.157.9 4-8 weeks6.352.3 9.161.5 >8 weeks5.151.10.416.762.70.581       Weeks for NAC to Surgery      <8 weeks549.5 9.160.7 >8 weeks5.151.10.5856.762.70.414

Table 2 :Time Interval - Molecular Subtype  RFS  OS  MEDIAN5 - yearsPMEDIAN5 - yearsPLUMINAL A LIKE      < 8 weeks----74.1 ----84 >8 weeks7.163.80.719.973.90.236       *LUMINAL B LIKE      < 8 weeks2.336.8 5.460.5 >8 weeks5.857.60.46----820.08       HER2      <8 weeks2.228.7 3.938.4 >8weeks3.645.90.57.26.261.30.616       TRIPLE NEGATIVE      <8 weeks3.144.2 3.448.4 >8 weeks2.041.80.9143.743.90.516* ER + PR >20% KI67>14% , HER2 NEGATIVE

Conclusion: The time interval between the end of neoadjuvant period and surgery has no impact on recurrence-free survival or on overall survival, despite this we suggest that the period of time between neoadjuvant and surgery not be greater than 8 weeks. More studies will be required to determine the ideal time interval and which cases should be prioritized according to the characteristics of our patients.

Citation Format: Rebaza LP, Galarreta JA, Castañeda C, Cotrina JM, Vilchez S, de la Cruz M, Ponce J, Aguilar A, Flores C, Castillo M, Galvez M, Vigil C. Impact of the time interval between neoadjuvant chemotherapy and surgery in Latin-Americans breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-14-12.

Abstract P6-09-04: Predictive factors for considering to avoid axillar lymphadenectomy in selected node positive breast cancer patients after neoadjuvant chemotherapy

Background:

To perform a systematic axillar lymphadenectomy (ALND) in clinical node positive (N+) patients after neoadjuvant chemotherapy (NACT) is currently under discussion. We aimed to study which factors are related to a pathological complete axillar response (ypN0) after NACT in order to select which patients could benefit from a sentinel lymph node biopsy without interfering with survival.

Material and methods

N+ patients who underwent ALND after NACT between June 2008 and December 2016 were retrospectively analyzed. Clinical features, molecular and histological factors, recurrence and specific mortality rates were compared between patients achieving a complete pathological axillary response vs not (ypN0 vs ypN+).

Results

345 N+ patients were reviewed. After NACT, 137 (39.6%) become ypN0[CF1] , 9 (2.6%) ypN1 mic, 113 (32.7%) ypN1, 60 (17.3%) ypN2 and 22 (6.4%) N3. Univariate analysis results regarding the predictive factors for ypN0 are detailed in [table 1]. Multivariate analyses showed molecular subtype (TN and Her2+) and clinical response as independent predictors of ypN0 [table 2]. After a mean follow-up of 58 months, overall survival was statistically superior in ypN0 vs ypN1 (p= 0.001).

Table 1.Predictive factors for ypN0 YpN0 (n = 137)YpN+ (n = 208)pAge (mean, years)58.3 ± 13.2758.59 ± 12.340.799BMI (mean)27.8±5.4927.8±5.360.973Dosis of QT (median)(%)  0.575IIA6 (31.6)13 (68.4) IIB71 (39.3)110 (60.8) IIIA28 (36.8)48 (63.2) IIIB24 (43.6)31 (56.4) IIIC7 (58.3)5 (41.7) Radiological image(%)  0.930Nodule77 (38.1)125 (61.9) Non-mass distortion10 (43.5)13 (56.5) Radiological size (median)32 (0-115)29 (0-130)0.246Suspicious a-LN by US(%)  0.486130 (30.9)37 (24.3) 25 (5.2)14 (9.2) >257 (58.8)91 (59.9) Histological subtype(%)  0.093Invasive Ductal Carcinoma133 (40.9)192 (59.1) Invasive Lobular Carcinoma2 (20)8 (80) Others2 (22.2)7 (78.8) Nottingham grade(%)  <0.001G11 (6.2)15 (93.8) G244 (28.6)110 (71.4) G386 (53.4)75 (46.6) Molecular-like subtype(%)  <0.001Luminal A-like2 (5.3)36 (94.7) Luminal B-like (Her2 -)21(18.1)95 (81.9) Luminal B-like (Her2 +)40 (63.5)23 (36.5) HER-2 enriched (non luminal)43 (74.1)15 (25.9) Triple Negative31 (44.9)38 (55.1) Vascular invasion19 (42.2)26 (57.8)0.889Clinical Response(%)  <0.001Complete61 (75.3)20 (24.7) Partial69 (31.8)148 (68.2) No response6 (20.7)23 (79.3) Progression1 (10)9 (90) Percentage are given per row.

Table 2.Multivariate analysis logistic regression of clinical predictive factors of ypN0. OR95% Confidence Intervalp valueMolecular subtype   No-luminal vs Luminal7,7483,913-15,343<0,001Clinical response   Response vs not response6,8491,834-25,5710,04OR: Odd ratio. No-luminal includes: luminal B (HER2 +), HER2 Henriched and triple negative. Luminal includes: Luminal A and Luminal B (HER2 -).

Conclusions

A remarkable percentage of N+ became ypN0 after NATC. Molecular subtype and complete clinical response were independent predictive factors of ypN0. We propose to offer the benefit of a targeted axillary procedure in those patients.

Citation Format: Fernandez-Gonzalez S, Falo Zamora C, Nuñez D, Vethencourt A, Pla MJ, Soler T, Guma A, Perez X, Gil M, Ponce J, Garcia A. Predictive factors for considering to avoid axillar lymphadenectomy in selected node positive breast cancer patients after neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-09-04.

Abstract P3-13-07: Is radiofrequency ablation better than lumpectomy for margin status in breast cancer? Results of a randomized clinical trial

PURPOSE: To study the safety and efficacy of ultrasound-guided percutaneous radiofrequency ablation (RFA) as local treatment for breast cancer and to intraoperatively evaluate the margin status after RFA in comparison with lumpectomy.

MATERIAL and METHODS: Preliminary in vitro RF ablation experimentation with two mastectomy specimens was performed to test the electrode, practice the ultrasound technique and evaluate the macroscopic and microscopic effects of RF. Then, aprospective, randomized open-label phase II clinical trial (NCT02281812) was conducted in a single institution from 2013-2017. Forty subjects, mean age 64 (range 46-86), with ductal infiltrating carcinoma of the breast ≤2 cm were randomly assigned to RFA plus lumpectomy or lumpectomy alone. Margin status, tumor cell viability (TCV) after RFA (by nicotinamide adenine dinucleotide (NADH) and Cytokeratin 18 (CK18) staining), adverse events and local recurrences were evaluated by univariable and multivariable analyses (SPSS statistical software).

RESULTS: In the experimental design with mastectomies, the only procedural complication was a skin burn at the entrance site of the electrodes. We learned that the tip of the electrodes should cut cross the tumor by at least 10mm.

The clinical trial includes two groups: study group (n=20) and control group (n=20). NADH and CK18 staining demonstrated absence of TCV after RFA with at least one of the two techniques. The percentage of intraoperatively affected surgical margins was higher in the control group although local adverse effects after surgery was higher in the RFA treatment arm. Three study subjects presented local infection (two had partial irradiation of the breast) and none in the control group. Median follow up was 25 months (range 1–83). No recurrence or second surgery was required during the study period.

Outcomes RFA group (n = 20)Control group (n=20)p valueSpecimen weight (median, gr)42 (24-80)27 (11-60)0.004Specimen volume (median, ml)369 (259-847)201 (100-602)0.004Positive margin (intraoperative)4/20 (20%)11/20 (55%)0.022Pathological size (median, mm)11.5 (5-20)10.5 (6-16)0.07Local Adverse effect8/20 (40%)1/20 (5%)0.01Breast Inflammation5/20 (25%)1/20 (5%)0.182Breast Infection3/20 (15%)0/20 (0%)0.23RFA: radiofrequency ablation. n=number of subjects

CONCLUSION: RFA seems effective in the cases considered and could be more accurate than lumpectomy in terms of obtaining more free margins. Surgical excision associated with RFA leads to a higher amount of local adverse effects, especially if combined with partial irradiation of the breast. RFA could be considered as a less invasive treatment in tumors smaller than 20 mm; however, this warrants further investigation.

Citation Format: Garcia-Tejedor A, Guma A, Soler T, Valdivieso A, Petit A, Contreras N, Chappuis CG, Falo C, Pernas S, Anselem A, Fernandez-Montoli E, Pla MJ, Burdio F, Ponce J. Is radiofrequency ablation better than lumpectomy for margin status in breast cancer? Results of a randomized clinical trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-13-07.

Abstract P2-08-58: Prognostic factors of survival in node positive breast cancer patients after neoadjuvant chemotherapy in a large series after 5y follow-up: Can response overcome the poor prognosis of nodal stage?

Background: Status of the axilla is one of the most significant prognostic factors in breast cancer (BC) patients. On the other hand, response to neoadjuvant chemotherapy (NACT) is related to survival. The aim of the present study is to analyze which prognostic factors impact most on Node positive (N+) BC patient survival after NATC. Material and methods: Retrospective analyses on a series of N+ BC patients treated with NATC based on anthracyclines and taxanes +/- trastuzumab if HER2 positive tumors, between June 2008 and December 2016. Clinical, radiological and pathological outcomes have been evaluated. Residual cancer burden (RCB) 1 and the neoadjuvant response index (INR) 2 have been recorded. Survival was calculated with Kaplan-Meier survival curve since the start of NATC to the first documented disease recurrence (DFS) or death (OS). Hazard ratios (HRs) with 95% CIs were estimated with cox proportional hazards regression analysis and subgroups were compared with a two-sided log-rank test. Results: A total of 345 N+ BC patients were included. Pathological complete response was achieved in 72 (20.8%) patients. After NACT, 137 (39.6%) become ypN0, 9 (2.6%) ypN1 mic, 113 (32.7%) ypN1, 60 (17.3%) ypN2 and 26 (7.6%) N3. Those independent predictive factor of ypN0 were molecular subtype (TN and Her2+) with OR: 7.7, p<0.001 and clinical response with OR 6.88, p: 0.04. At a mean follow-up of 58 months there have been 73 (21.1%) recurrences: 9 (2.3%) local, 45 (13%) systemic, 15 (4.3%) systemic+ local, 3 (0.9%) axilla, 1 (0.3%) supraclavicular. The estimated 5y OS was 87.8%. The univariate analysis according to DSF is detailed in Table1.

Adjusted univariate anaalysis cox regression of clinical and pathological factors of desease free survivalBMI10.989-1.010.963AGE0.9960.953-1.0420.876Dose NATC0.9940.979-1.0080.402Clinical Stage1.4021.077-1.8260.012Rx Image1.260.803-1.9940.311Rx size1.0090.995-1.0240.217Number suspicious ALN1.0950.801-1.4970.57Molecular subtype TN,HER20.8800.534-1.450.616Nottinghan grade1.0460.753-1.4530.789Histological subtype1.4651.044-2.0570.27MOlecular subtype1.1510.956-1.3850.137Vascular invasion1.6761.137-24710.009Clinical response2.3691.709-3.284<0.001Fibrosis tumor bed0.980.972-0.989<0.001Nodal fibrosis>50%1.7950.874-3.6860.111Pathological tumoral response1.6861.175-2.4180.005ypN03.561.853-6.838<0.001NRI0.330.192-0.565<0.001RCB1.2741.106-1.4680.001

In the multivariate model those parameters that were independently prognostic were clinical response HR: 5.44 (IC95% 2.275-13.042, p<0.001) and clinical stage HR: 2.364 (IC95% 1.018-5.490, p: 0.045). Conclusions: The most significant prognostic factor in our N+ series was response to NATC, followed by clinical stage. Those independently predictive factors of axillar response (ypN0) were molecular subtype (TN and Her2+) and clinical response. In conclusion, in those patients with chemo sensitive tumors, lymphadenectomy could be safely spared with a more selective axillary approach.

Citation Format: Fernandez S, Garcia A, Vethencourt A, Vazquez S, Petit A, Pla MJ, Ortega R, Pérez J, Gil M, Ponce J, Pernas S, Lopez A, Falo C. Prognostic factors of survival in node positive breast cancer patients after neoadjuvant chemotherapy in a large series after 5y follow-up: Can response overcome the poor prognosis of nodal stage? [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-58.

Decreased Esophageal Sensitivity to Acid in Morbidly Obese Patients: A Cause for Concern?

Background/Aims

To evaluate esophageal sensitivity to acid between morbidly obese (MO) patients and non-MO controls with abnormal esophageal acid exposure.

Methods

We conducted a cross-sectional study of 58 patients: 30 MO (cases) and 28 non-MO (controls). Esophageal symptoms and esophageal sensitivity to 0.1 M hydrochloric acid solution (Bernstein test) were compared between MO and non-MO patients with a prior diagnosis of abnormal esophageal acid exposure.

Results

MO patients were less symptomatic than non-MO controls (14% vs 96%; odds ratio [OR], 0.006; 95% confidence interval [CI], 0.001 to 0.075; p=0.000). MO patients were more likely to present with decreased esophageal sensitivity to the instillation of acid than non-MO controls (57% vs 14%; OR, 8; 95% CI, 1.79 to 35.74; p=0.009). Subgroup analysis revealed no differences in esophageal sensitivity in MO patients with and without abnormal esophageal acid exposure (43% vs 31%; p=0.707).

Conclusions

Silent gastroesophageal reflux disease (GERD) is common among MO individuals, likely due to decreased esophageal sensitivity to acid. The absence of typical GERD symptoms in these patients may delay discovery of precancerous conditions, such as Barrett’s esophagus. We believe that these patients may require a more aggressive diagnostic work-up to rule out the presence of silent GERD.