Investigator

Lukas J. A. Stalpers

radiation oncologist · Amsterdam UMC Location University of Amsterdam

Research Interests

LJALukas J. A. Stalp…
Papers(4)
Increased human papil…Advanced patient-spec…Comparison of the cli…Radical hysterectomy …
Collaborators(10)
Johannes CrezeeH. Petra KokM. Willemijn KolffNienke E van TrommelPetra L.M. ZusterzeelRamon G.V. SmoldersRenske DM SteenbergenRonald P. ZweemerRuud L. M. BekkersSeth‐Frerich Fobian
Institutions(8)
University Of Amsterd…Amsterdam University …The Netherlands Cance…Unknown InstitutionErasmus University Me…Vrije Universiteit Am…University Medical Ce…Maastricht University

Papers

Advanced patient-specific hyperthermia treatment planning

Hyperthermia treatment planning (HTP) is valuable to optimize tumor heating during thermal therapy delivery. Yet, clinical hyperthermia treatment plans lack quantitative accuracy due to uncertainties in tissue properties and modeling, and report tumor absorbed power and temperature distributions which cannot be linked directly to treatment outcome. Over the last decade, considerable progress has been made to address these inaccuracies and therefore improve the reliability of hyperthermia treatment planning. Patient-specific electrical tissue conductivity derived from MR measurements has been introduced to accurately model the power deposition in the patient. Thermodynamic fluid modeling has been developed to account for the convective heat transport in fluids such as urine in the bladder. Moreover, discrete vasculature trees have been included in thermal models to account for the impact of thermally significant large blood vessels. Computationally efficient optimization strategies based on SAR and temperature distributions have been established to calculate the phase-amplitude settings that provide the best tumor thermal dose while avoiding hot spots in normal tissue. Finally, biological modeling has been developed to quantify the hyperthermic radiosensitization effect in terms of equivalent radiation dose of the combined radiotherapy and hyperthermia treatment. In this paper, we review the present status of these developments and illustrate the most relevant advanced elements within a single treatment planning example of a cervical cancer patient. The resulting advanced HTP workflow paves the way for a clinically feasible and more reliable patient-specific hyperthermia treatment planning.

Radical hysterectomy or chemoradiotherapy for clinically early-stage cervical cancer with suspicious lymph nodes on imaging: a retrospective cohort study

The optimal treatment of clinically early-stage cervical cancer with suspicious lymph nodes on pretreatment imaging is unclear. Therefore, we aimed to compare surgery (i.e., radical hysterectomy and pelvic lymphadenectomy±adjuvant therapy) with primary chemoradiotherapy as treatment strategies in this patient group regarding recurrence-free, overall survival and toxicity. Women diagnosed between 2009-2017 with the International Federation of Gynecology and Obstetrics (2009) stage IA-IIA and suspicious nodes based on radiologic assessment of pretreatment imaging were retrospectively selected from the Netherlands Cancer Registry. Cox proportional hazard was used to estimate survival and logistic regression for toxicity. Inverse probability weighting was used to correct for confounding. Grade ≥2 surgery-related (≤30 days) and grade ≥3 chemotherapy or radiotherapy-related (≤6 months) toxicity were collected. Missing data were imputed. Of 330 patients included, 131 (40%) received surgery (followed by adjuvant therapy in 54%) and 199 (60%) chemoradiotherapy. Pathological nodal status was known in 100% of the surgery group and 32% (n=63) of the chemoradiotherapy group, of whom 43% (56/131) and 89% (56/63), respectively, had metastases. After adjustment for confounders, the recurrence-free survival (hazard ratio [HR]=0.67; 95% confidence interval [CI]=0.34-1.31) and overall survival (HR=0.75; 95% CI=0.38-1.47) were not significantly different between both groups, while surgery was associated with more toxicity (odds ratio=2.82; 95% CI=1.42-5.60), mainly surgery-related. In patients with clinically early-stage cervical cancer and suspicious nodes on imaging, surgery and primary chemoradiotherapy yielded comparable results in terms of survival, whereas surgery might be associated with more (surgery-related) short-term toxicity.

14Works
4Papers
28Collaborators
Uterine Cervical NeoplasmsBreast NeoplasmsCell Line, TumorNeoplasm StagingPapillomavirus InfectionsUterine Cervical DiseasesDisease Models, AnimalNeoplasm Metastasis

Positions

radiation oncologist

Amsterdam UMC Location University of Amsterdam

Education

MD, PhD

AMC · Radiation Oncology

Country

NL