Investigator

Johannes Crezee

Principal Investigator · Amsterdam UMC Locatie AMC, Radiation Oncology

About

Research Interests

JCJohannes Crezee
Papers(5)
Increased human papil…Advanced patient-spec…Comparison of the cli…Biological treatment …High human papillomav…
Collaborators(10)
Lukas J. A. StalpersH. Petra KokSeth‐Frerich FobianRenske DM SteenbergenTimo L. M. ten HagenWillem de KoningXionge MeiAkke BakkerAndrew P. StubbsArlene L. Oei
Institutions(5)
University Of Amsterd…Amsterdam University …Vrije Universiteit Am…Erasmus MCErasmus MC

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.

Biological treatment evaluation in thermoradiotherapy: application in cervical cancer patients

Abstract Background Hyperthermia treatment quality is usually evaluated by thermal (dose) parameters, though hyperthermic radiosensitization effects are also influenced by the time interval between the two modalities. This work applies biological modelling for clinical treatment evaluation of cervical cancer patients treated with radiotherapy plus hyperthermia by calculating the equivalent radiation dose (EQDRT, i.e., the dose needed for the same effect with radiation alone). Subsequent analyses evaluate the impact of logistics. Methods Biological treatment evaluation was performed for 58 patients treated with 23–28 fractions of 1.8–2 Gy plus 4–5 weekly hyperthermia sessions. Measured temperatures (T50) and recorded time intervals between the radiotherapy and hyperthermia sessions were used to calculate the EQDRT using an extended linear quadratic (LQ) model with hyperthermic LQ parameters based on extensive experimental data. Next, the impact of a 30-min time interval (optimized logistics) as well as a 4‑h time interval (suboptimal logistics) was evaluated. Results Median average measured T50 and recorded time intervals were 41.2 °C (range 39.7–42.5 °C) and 79 min (range 34–125 min), respectively, resulting in a median total dose enhancement (D50) of 5.5 Gy (interquartile range [IQR] 4.0–6.6 Gy). For 30-min time intervals, the enhancement would increase by ~30% to 7.1 Gy (IQR 5.5–8.1 Gy; p < 0.001). In case of 4‑h time intervals, an ~ 40% decrease in dose enhancement could be expected: 3.2 Gy (IQR 2.3–3.8 Gy; p < 0.001). Normal tissue enhancement was negligible (< 0.3 Gy), even for short time intervals. Conclusion Biological treatment evaluation is a useful addition to standard thermal (dose) evaluation of hyperthermia treatments. Optimizing logistics to shorten time intervals seems worthwhile to improve treatment efficacy.

High human papillomavirus viral load and local immune dysregulation are associated with poor clinical outcomes in patients with cervical cancer.

Human papillomavirus (HPV) infection is the primary cause of cervical cancer. Higher viral load, that is, a greater abundance of HPV DNA in a tumor, has been associated with poorer clinical outcomes, and may play a role in the more accurate prediction of (non-) responders to treatment. In this study, we investigated the correlation between HPV viral load, clinical outcomes, and immune parameters related to HPV infection. HPV viral load was quantified using quantitative polymerase chain reaction on biopsies from a prospective cohort of women diagnosed with cervical cancer. Patients were categorized into 2 HPV viral load groups based on the optimal fit of a non-linear piecewise regression model. Immunohistochemical staining was used to measure tumor cell characteristics (Ki67, p16 In the 44 women included in our study, high HPV viral load was significantly associated with shorter overall and recurrence-free survival (p = .045 and p = .046, respectively; 2-sided) and positively correlated with an increased risk of lymph node and distant metastasis. In addition, a high HPV viral load was linked to lower percentages of tumor-infiltrating lymphocytes and reduced expression levels of PD-1 and PD-L1. The viral load of HPV in cervical cancer correlates positively to metastasis and recurrence and negatively to survival rates, potentially because of local immune suppression. These results might indicate a lower response to immune checkpoint inhibition in the high viral load group and that other treatment options should still be explored.

237Works
5Papers
17Collaborators
Uterine Cervical NeoplasmsNeoplasmsCell Line, TumorColorectal NeoplasmsUrinary Bladder NeoplasmsPeritoneal NeoplasmsNeoplasm Recurrence, LocalBreast Neoplasms

Positions

2008–

Principal Investigator

Amsterdam UMC Locatie AMC · Radiation Oncology

2000–

assistant professor

Amsterdam UMC Locatie AMC · Radiation Oncology

1988–

Researcher

University Medical Center Utrecht · Radiation Oncology

Education

1993

PhD

Utrecht University · Radiation Oncology

1986

M.Sc.

Vrije Universiteit Amsterdam · Experimental Physics

Keywords
hyperthermiabio heat modelingheat transfertreatment planning