Multi-modal volumetric concept activation to explain detection and classification of metastatic prostate cancer on PSMA-PET/CT

Explainable artificial intelligence (XAI) is increasingly used to analyze the behavior of neural networks. Concept activation uses human-interpretable concepts to explain neural network behavior. This study aimed at assessing the feasibility of regression concept activation to explain detection and classification of multi-modal volumetric data. Proof-of-concept was demonstrated in metastatic prostate cancer patients imaged with positron emission tomography/computed tomography (PET/CT). Multi-modal volumetric concept activation was used to provide global and local explanations. Sensitivity was 80% at 1.78 false positive per patient. Global explanations showed that detection focused on CT for anatomical location and on PET for its confidence in the detection. Local explanations showed promise to aid in distinguishing true positives from false positives. Hence, this study demonstrated feasibility to explain detection and classification of multi-modal volumetric data using regression concept activation.Comment: Accepted as: Kraaijveld, R.C.J., Philippens, M.E.P., Eppinga, W.S.C., J\"urgenliemk-Schulz, I.M., Gilhuijs, K.G.A., Kroon, P.S., van der Velden, B.H.M. "Multi-modal volumetric concept activation to explain detection and classification of metastatic prostate cancer on PSMA-PET/CT." MICCAI workshop on Interpretability of Machine Intelligence in Medical Image Computing (iMIMIC), 202

Symptomatic lymphocele after robot-assisted pelvic lymphadenectomy as part of the primary surgical treatment for cervical and endometrial cancer: a retrospective cohort study

Study Objectives: Pelvic lymph node dissection (PLND) is part of the primary treatment for early–stage cervical cancer and high–intermediate risk or high–risk endometrial cancer. Pelvic lymphocele is a postoperative complication of PLND, and when symptomatic, lymphoceles necessitate treatment. The aim of this study was to investigate the incidence and risk factors of symptomatic lymphocele after robot–assisted laparoscopic PLND in cervical and endometrial cancer. Design: Retrospective cohort study. Setting: Single–center academic hospital. Patients: Two hundred and fifty–eight patients with cervical cancer and 129 patients with endometrial cancer. Interventions: Pelvic lymphadenectomy by robot–assisted laparoscopic surgery. Measurements and Main Results: The authors retrospectively included all patients with early–stage cervical cancer and high–intermediate risk or high–risk endometrial cancer who underwent pelvic lymphadenectomy by robot–assisted laparoscopic surgery between 2008 and 2022. Medical records were reviewed for the occurrence of a symptomatic lymphocele. Univariate and multivariate logistic regression analyses were conducted to identify risk factors for developing a symptomatic lymphocele. In total, 387 patients, 258 with cervical cancer and 129 with endometrial cancer, were included in the study. The overall incidence of symptomatic lymphoceles was 9.6% with a median follow–up of 47 months [interquartile range 23–61]. For the entire cohort, smoking was the only significant risk factor for symptomatic lymphoceles identified in univariate (OR 2.47, 95% CI 1.19–5.11) and multivariate analysis (OR 2.42, 95% CI 1.16–5.07). For cervical cancer, body mass index (BMI) (OR 1.09, 95% CI 1.00–1.17) and prior abdominal surgery (OR 2.75, 95% CI 1.22–6.17) were also identified as significant independent risk factors. For endometrial cancer, age was identified as a significant independent risk factor (OR 0.90, 95% CI 0.83–0.97). Conclusion: This single–center cohort study demonstrated an incidence of almost 10% of symptomatic lymphoceles after robot–assisted laparoscopic PLND for cervical cancer and endometrial cancer, with a higher risk observed among patients who smoke at the time of diagnosis. Furthermore, risk factors differ between the 2 populations, necessitating further studies to establish risk models

The influence of learning curve of robot-assisted laparoscopy on oncological outcomes in early-stage cervical cancer: an observational cohort study

OBJECTIVE: To investigate the learning curve of robot-assisted laparoscopy in early-stage cervical cancer and quantify impact on oncological outcomes. DESIGN: Observational cohort study. SETTING: Tertiary referral centre with one surgical team. POPULATION: All women with early-stage cervical cancer treated consecutively with robot-assisted laparoscopy between 2007 and 2017. METHODS: With multivariate risk-adjusted cumulative sum analysis (RA-CUSUM), we assessed the learning curve of robot-assisted laparoscopy of a single surgical team based on cervical cancer recurrence. Subsequently, a survival analysis was conducted comparing oncological outcomes of women treated during different phases of the learning curve. MAIN OUTCOME MEASURES: Surgical proficiency based on recurrence, survival rates in the different learning phases. RESULTS: One hundred and sixty-five women with cervical cancer underwent robot-assisted laparoscopy, with a median follow up of 57 months (range 3-132 months). The RA-CUSUM analysis demonstrated two phases of the learning curve: a learning phase of 61 procedures (group 1) and an experienced phase representing the 104 procedures thereafter (group 2). The 5-year disease-free survival was 80.2% in group 1 and 91.1% in group 2 (P = 0.040). Both the 5-year disease-specific survival and overall survival significantly increased after the learning phase. CONCLUSION: The learning phase of robot-assisted laparoscopy in early-stage cervical cancer in this institutional cohort is at least 61 procedures, with higher survival rates in the women treated thereafter. The learning curve of robot-assisted laparoscopy affects oncological outcomes and warrants more attention in the design of future studies. TWEETABLE ABSTRACT: The learning curve of robot-assisted laparoscopy in early-stage cervical cancer affects oncological outcomes and warrants more attention

Fertility-sparing surgery and fertility preservation in cervical cancer: The desire for parenthood, reproductive and obstetric outcomes

Objective: To evaluate the desire for parenthood and reproductive outcomes of young cervical cancer survivors who underwent fertility-sparing surgery or fertility preservation procedures for invasive cervical cancer. Methods: All women <45 years who underwent fertility-sparing treatment for invasive cervical cancer in a tertiary referral center in the Netherlands between January 2009 and January 2020 were identified. Fertility-sparing treatment options included Vaginal Radical Trachelectomy (VRT) for patients with early-stage disease and fertility preservation techniques (FP) when requiring Radical Hysterectomy (RH) or chemoradiotherapy. Data on reproductive intentions – and outcomes were retrieved from medical files and questionnaires. Results: 75 patients were identified of whom 34 underwent VRT, 9 RH and 32 had (chemo)radiotherapy. 26 patients started FP of whom 23 (88.5%) successfully preserved fertility through cryopreservation of embryos, oocytes and ovarian tissue. After a median follow-up of 49 months, 5 patients developed recurrent disease and died. Reproductive outcomes were retrieved in 58 patients. 89.6% maintained their desire for parenthood after cancer treatment. Following VRT, we report a pregnancy rate of 61.9% among the patients attempting conception (n = 24). 15 patients conceived 21 pregnancies which resulted in 15 live-births, yielding a live-birth rate of 75.0%. Following RH or (chemo)radiotherapy, 3 surrogate pregnancies were established (21.4%) using frozen-thawed material with good neonatal outcomes. Conclusion: Many cervical cancer survivors maintain the desire to become parents eventually. In early-stage disease, VRT shows good reproductive outcomes without compromising oncological safety. For those requiring gonadotoxic treatment fertility preservation and gestational surrogacy provides a promising alternative for achieving a biological offspring

Lymphocele following lymph node dissection in cervical and endometrial cancer: A systematic review and meta-analysis

Objectives: The purpose of this systematic review and meta-analysis was to evaluate the proportion and risk factors of lymphoceles and symptomatic lymphoceles after PLND in early-stage cervical and early-stage high or high-intermediate risk endometrial cancer. Methods: Studies reporting on the proportion of lymphocele after PLND were conducted in PubMed, Embase and Cochrane Library. Retrieved studies were screened on title/abstract and full text by two reviewers independently. Quality assessment was conducted using the Newcastle Ottowa Scale and the Cochrane risk-of-bias tool. Proportion of lymphocele and possible risk factors were pooled through random-effects meta-analyses. Results: From the 233 studies retrieved, 24 studies were included. The pooled proportion of lymphocele was 14% and of symptomatic lymphocele was 3%. Routinely performing diagnostics was associated with a significantly higher proportion of lymphocele compared to diagnostics performed on indication (21% versus 4%, p 15% of the study population underwent additional paraaortic lymph node dissection (PAOLND) opposed to <15% (15% versus 3%, p < 0.01). A mean number of lymph nodes dissected of <21 resulted in a significantly higher pooled proportion of lymphoceles opposed to when the mean number was 21 or higher (19% versus 5%, p = 0.02). Other risk factors analysed were BMI, lymph node metastasis, adjuvant radiotherapy and follow up. There was no sufficient data to detect significant risk factors for the development of symptomatic lymphoceles. Conclusion: The pooled proportion of lymphocele was 14% of which symptomatic lymphoceles occurred in 3%. Significant risk factors for the total proportion of lymphoceles were laparotomic approach, decreased number of lymph nodes dissected and additional PAOLND

Introducing a novice surgeon to an experienced robotic gynaecological oncology team: An observational cohort study on the impact of a structured curriculum on outcomes of cervical cancer surgery

Objective: To evaluate the effect on patient outcomes when introducing a novice robotic surgeon, trained in accordance with a structured learning curriculum, to an experienced robotic surgery team treating cervical cancer patients. Methods: Patients with early-stage cervical cancer who were treated with primary robot-assisted surgery between 2007 and 2019 were retrospectively included. In addition to the 165 patients included in a former analysis, we included a further 61 consecutively treated patients and divided all 226 patients over three groups: early learning phase of 61 procedures without structured training (group 1), experienced phase of 104 procedures (group 2), and the 61 procedures during introduction of a novice with structured training (group 3). Risk-adjusted cumulative sum (RA-CUSUM) analysis was performed to assess the learning curve effect. Patient outcomes between the groups were compared. Results: Based on RA-CUSUM analysis, no learning curve effect was observed for group 3. Regarding surgical outcomes, mean operation time in group 3 was significantly shorter than group 1 (p < 0.001) and similar to group 2 (p = 0.96). Proportions of intraoperative and postoperative adverse events in group 3 were not significantly different from the experienced group (group 2). Regarding oncological outcomes, the 5-year disease-free survival, disease-specific survival, and overall survival in group 3 were not significantly different from the experienced group. Conclusions: Introducing a novice robotic surgeon, who was trained in accordance with a structured learning curriculum, resulted in similar patient outcomes as by experienced surgeons suggesting novices can progress through a learning phase without compromising outcomes of cervical cancer patients

Value of routine cytokeratin immunohistochemistry in detecting low volume disease in cervical cancer

Objective: In cervical cancer, sentinel lymph nodes (SLNs) are processed according to the pathological ultrastaging protocol. According to current guidelines, immunohistochemistry with pancytokeratin antibodies is performed in addition to step sectioning with hematoxylin and eosin (H&E), aiding the detection of low volume disease (micrometastasis and isolated tumor cells (ITC)). We studied the added clinical value, and costs, of routine immunohistochemistry (IHC). Methods: We retrospectively included all FIGO stage IA-IIA1 cervical cancer patients who had undergone SLN procedures at UMC Utrecht from 2008 to 2020. Pathological data were derived from the Dutch Pathology Registry (PALGA) including SLN tumor status and number of slides stained with IHC. Results: In total 234 cervical cancer patients were included. In the 516 surgically resected SLN specimens, 630 SLNs were discovered by the pathologist. Hereof, 579 SLNs from 211 patients were routinely processed with IHC. IHC identified three patients with micrometastasis and five patients with ITC undetected with H&E staining. Thereby, IHC significantly increased the number of patients with low volume disease from 11 (5.3%) to 19 patients (9.1%) (p = 0.04). To achieve this, 3791 slides were stained with IHC at an estimated additional cost of €94,775. In 1.4% (95% CI 0.3%–4.3%) of patients routine use of IHC adjusted the adjuvant treatment. Conclusions: Routine use of IHC increases detection of low volume disease in cervical cancer SLNs compared to step sectioning with H&E alone by nearly 4%, with an impact on therapeutic strategy-decisions in about 1% of patients. In view of the high associated costs, cost-effectiveness of routine IHC is questionable

Upstaging by para-aortic lymph node dissection in patients with locally advanced cervical cancer: A systematic review and meta-analysis

Background: Accurate staging of para-aortic nodal status in cervical cancer is of great importance for individualizing treatment and impacting outcomes. Three-dimensional imaging (i.e. PET, CT, MRI) may miss para-aortic lymph node (PALN) metastases. The aim of this study was to systematically review and meta-analyze the proportion of upstaging by PALN dissection in patients with locally advanced cervical cancer without suspicious PALNs on imaging. Methods: PubMed/MEDLINE and Embase were systematically searched. The analysis included diagnostic studies that reported on 3D imaging and pre-therapeutic surgical assessment of PALN status in patients with cervical cancer. An overall pooled upstaging rate was calculated using a random-effects model. Results: The search identified 16 eligible studies including 18 cohorts with a total of 1530 patients. Pooling of 12 cohorts demonstrated an upstaging rate of 12% (95% confidence interval [CI] 10–15%) by PALN dissection after negative PET or PET-CT. Pooling of 6 cohorts demonstrated a pooled upstaging rate of 11% (95% CI: 8–16%) by PALN dissection after negative MRI or CT. No significant heterogeneity in upstaging proportions across cohorts was observed (I2 = 0% and 27%, respectively). In 7 cohorts including only patients with pelvic nodal metastases on imaging (but no suspicion of PALN involvement) a pooled upstaging rate by PALN dissection of 21% (95% CI: 17–26%) was found (I2 = 0%). Conclusions: This meta-analysis demonstrates that in case of no suspicious PALN on PET-CT or MRI, PALN dissection still identifies lymph node metastases in a considerable amount of patients with locally advanced cervical cancer and especially in those patients with confirmed pelvic nodal metastases

Fluorescent Indocyanine Green versus Technetium-99m and Blue Dye for Bilateral SENTinel Lymph Node Detection in Stage I-IIA Cervical Cancer (FluoreSENT): protocol for a non-inferiority study

INTRODUCTION: Nowadays, two predominant methods for detecting sentinel lymph nodes (SLNs) in cervical cancer are in use. The most conventional method is a combination of a radiotracer, technetium-99m ( 99mTc) and blue dye. More recently, another method for SLN mapping using indocyanine green (ICG) is becoming widely accepted. ICG is a fluorescent dye, visualised intraoperatively with near-infrared (NIR) fluorescence imaging, providing real-time visual navigation. The presumed advantages of ICG over 99mTc, that is, being cheaper, non-radioactive and logistically more attractive, are only valuable if its detection rate proves to be at least non-inferior. Before omitting the well-functioning and evidence-based combined approach of 99mTc and blue dye, we aim to provide prospective evidence on the non-inferiority of ICG with NIR fluorescence imaging. METHODS AND ANALYSIS: We initiated a prospective non-inferiority study with a paired comparison of both SLN methods in a single sample of 101 patients with International Federation of Gynecology and Obstetrics (FIGO) stage IA-IB2 or IIA1 cervical cancer receiving primary surgical treatment. All patients undergo SLN mapping with ICG and NIR fluorescence imaging in adjunct to mapping with 99mTc (including single photon emission computed tomography with X-ray computed tomography (SPECT/CT)) and blue dye. Surgeons start SLN detection with ICG while being blinded for the preoperative outcome of SPECT/CT to avoid biased detection with ICG. Primary endpoint of this study is bilateral SLN detection rate of both methods (ie, detection of at least one SLN in each hemipelvis). Since we compare strategies for SLN mapping that are already applied in current daily practice for different types of cancer, no additional risks or burdens are expected from these study procedures. ETHICS AND DISSEMINATION: The current study is approved by the Medical Ethics Research Committee Utrecht (reference number 21-014). Findings arising from this study will be disseminated in peer-reviewed journals, academic conferences and through patient organisations. TRIAL REGISTRATION NUMBER: NL9011 and EudraCT 2020-005134-15

The impact of para-aortic lymph node irradiation on disease-free survival in patients with cervical cancer: A systematic review and meta-analysis

Background: Patients with locally advanced cervical cancer without para-aortic lymph node metastases (PAO-LNM) at diagnosis who undergo concurrent chemoradiotherapy are at 4-11% risk of developing PAO-LNM during follow-up. Some studies suggest a beneficial influence of elective para-aortic radiotherapy (PAO-RT) on disease-free survival (DFS) in these patients. The aim of this study was to systematically review and meta-analyse literature on the impact of PAO-RT on DFS in cervical cancer patients. Methods: A systematic search of PubMed/MEDLINE and EMBASE databases was performed. The analysis included intervention studies that reported on DFS in patients with cervical cancer who received chemotherapy and pelvic radiotherapy with or without PAO-RT. From each included study, relevant study characteristics and outcome data including the hazard ratio (HR) adjusted for potential confounders were extracted. An overall pooled adjusted hazard ratio (aHR) for DFS after PAO-RT versus no PAO-RT was calculated using a random-effects model. Results: A total of 2,016 articles were evaluated. Eleven articles were included in the systematic review, of which 3 were appropriate for quantitative meta-analysis. Pooling of these 3 cohorts (including 1,113 patients) demonstrated a statistically significant association between PAO-RT and DFS (pooled aHR 0.87, 95% confidence interval: 0.79-0.97). No significant heterogeneity among reported aHRs was observed (I 2 = 0.0%). Conclusions: This meta-analysis suggests a modest but significant beneficial impact of elective para-aortic radiotherapy on DFS in patients with locally advanced cervical cancer who undergo concurrent chemoradiotherapy. This finding based on non-randomized studies provides an imperative for further investigation in prospective controlled trials