About
70
Publications
9,972
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,916
Citations
Introduction
The Verwelius 3D lab founded in 2017 investigates 3D based technologies in Head & Neck Oncology and Surgery. The labs aim is to improve the predictability of the surgical and functional outcome of maxillectomy and mandibular resection procedures.
In addition, the 3D lab aims to improve in-vivo light dosimetry for m-THPC (Foscan) mediated Photodynamic Therapy by means of 3D image guided source positioning.
Additional affiliations
February 2006 - February 2012
Publications
Publications (70)
Purpose
This research aimed to develop an innovative method for designing and fabricating nasal prostheses that reduces anaplastologist expertise dependency while maintaining quality and appearance, allowing patients to regain their normal facial appearance.
Methods
The method involved statistical shape modeling using a morphable face model and 3D...
Background
Histopathological analysis often shows close resection margins after surgical removal of tongue squamous cell carcinoma (TSCC). This study aimed to investigate the agreement between intraoperative 3D ultrasound (US) margin assessment and postoperative histopathology of resected TSCC.
Methods
In this study, ten patients were prospectivel...
Purpose:
Intra-operative assessment of resection margins during oncological surgery is a field that needs improvement. Ultrasound (US) shows the potential to fulfill this need, but this imaging technique is highly operator-dependent. A 3D US image of the whole specimen may remedy the operator dependence. This study aims to compare and evaluate the...
Samenvatting
Doel van deze studie was de klinische toepasbaarheid van 3D-modellen onderzoeken in de preoperatieve planning van robotgeassisteerde radicale laparoscopische prostatectomie (RALP). Er werden 20 virtuele 3D-modellen en 3D-prints gemaakt, waarna 7 urologen op basis hiervan de mate van zijdespecifieke zenuwsparing bepaalden. Vervolgens we...
This study is to determine whether the volume and contact surface area (CSA) of a tumour with an adjacent prostate capsule on MRI in a three-dimensional (3D) model that can predict side-specific extraprostatic extension (EPE) at radical prostatectomy (RP). Patients with localised prostate cancer (PCa) who underwent robot-assisted RP between July 20...
The interpretation of conventional MRI may be limited by the two-dimensional presentation of the images. To develop patient-specific MRI prostate-based virtual and three-dimensional (3D)-printed models. To assess the association between 3D imaging and the pathological outcome of RARP specimen. To assess the clinical applicability of 3D models to gu...
Purpose:
To utilize navigated mandibular (reconstructive) surgery, accurate registration of the preoperative CT scan with the actual patient in the operating room (OR) is required. In this phantom study, the feasibility of a noninvasive hybrid registration method is assessed. This method consists of a point registration with anatomic landmarks for...
Image-to-patient registration in navigated mandibular surgery is complex due to the mobile nature of the mandible compared with other craniofacial bones. As a result, surgical navigation is rarely employed in the mandibular region. This systematic review provides an overview of the different registration methods that are used for surgical navigatio...
Introductie
Ten opzichte van twee-dimensionale beelden, tonen drie-dimensionale (3D) beelden ook diepte, geven ze meer informatie weer en is rotatie mogelijk. Deze studie onderzocht of MRI gebaseerde 3D prostaat modellen beter inzicht geven in de precieze locatie van prostaat carcinomen (PC) tov het prostaatkapsel en zo de preoperatieve planning va...
Background
Although an oncological surgeon aims to remove tongue cancer with a margin of no less than 5 mm, 85% of margins are reported as close or positive (<5mm). Currently, the only feedback on the status of margins is provided by frozen sections and standard post-operative histopathological assessment.
Objectives
To introduce a novel method fo...
Purpose: The planning of nerve-sparing (NS) surgery in robot-assisted radical prostatectomy (RARP) is limited to the low sensitivity of clinical and MRI variables to predict extracapsular extension. 3D MRI reconstruction may allow for better visualization of prostate cancer (PC) lesions and improve surgical planning. This study was aimed to assess...
The purpose of this study was to evaluate the feasibility of electromagnetic (EM) navigation for guidance on osteotomies in patients undergoing oncologic mandibular surgery. Preoperatively, a 3D rendered model of the mandible was constructed from diagnostic computed tomography (CT) images. Cutting guides and patient specific reconstruction plates w...
PurposeA dental splint was developed for non-invasive rigid point-based registration in electromagnetically (EM) navigated mandibular surgery. Navigational accuracies of the dental splint were compared with the common approach, that is, using screws as landmarks.MethodsA dental splint that includes reference registration notches was 3D printed. Dif...
Background
. Photodynamic therapy (PDT) is emerging as a promising treatment option for recurrent sinonasal malignancies. However, light administration in this area is challenging given the complex geometry, varying tissue optical properties and difficult accessibility. The goal of this study was to estimate the temporal and spatial variation in fl...
Purpose3D-printed cutting guides are the current standard to translate the virtual surgery plan to the intraoperative setting. The production of these patient-specific cutting guides is time-consuming and costly, and therefore, alternative approaches are currently subject of research. The aim of this study was to assess the accuracy and reproducibi...
In mandibular surgery, three-dimensionally printed patient-specific cutting guides are used to translate the preoperative virtually planned resection planes to the operating room. This study was performed to determine whether cutting guides are positioned according to the virtual plan and to compare the intraoperative position of the cutting guide...
The fabrication of auricular prostheses is traditionally time consuming, and the definitive esthetic appearance is highly skill dependent. A method of creating the wax pattern for an auricular prosthesis by using optical scanning and 3D printing is described. A digital scan of the unaffected ear is used for computer-aided design and manufacturing o...
Previous dosimetric studies during photodynamic therapy (PDT) of superficial lesions within a cavity such as the nasopharynx, demonstrated significant intra‐ and inter‐patient variations in fluence rate build‐up as a result of tissue surface re‐emitted and reflected photons, which depends on the optical properties. This scattering effect affects th...
Background and objectives:
There is a clinical need to assess the resection margins of tongue cancer specimens, intraoperatively. In the current ex vivo study, we evaluated the feasibility of hyperspectral diffuse reflectance imaging (HSI) for distinguishing tumor from the healthy tongue tissue.
Study design/materials and methods:
Fresh surgical...
Resection of maxillary cancer often results in incomplete excision because of the tumour’s proximity to important structures such as the orbit. To deal with this problem we prospectively investigated the feasibility of intraoperative imaging during maxillectomy to verify the planned resection margins. In total, six patients diagnosed with maxillary...
The standard treatment for early stage oral cancer is surgery with or without adjuvant radiotherapy. For some patients such treatments are not applicable, for example when adequate re-irradiation doses cannot be given due to previous therapy or when further surgery would be expected to lead to unacceptable functional morbidity. Photodynamic therapy...
Objective:
In case of close or positive resection margins after oncological resection in head and neck surgery, additional treatment is necessary. When conventional options are exhausted, photodynamic therapy (PDT) can play a role in achieving clear margins. The purpose of the current study was to evaluate the clinical benefit of PDT as adjuvant t...
Interstitial photodynamic therapy is a potentially important tool in the management of voluminous or deep-seated recurrent head and neck cancers.
The described treatment algorithm in this manuscript consists of the treatment simulation, implantation of light sources, verification, modification of the treatment plan if necessary, and illumination. T...
The treatment of persistent and recurrent nasopharyngeal carcinoma (NPC) remains a challenge, especially in Indonesia. We investigated the safety and efficacy of temoporfin mediated photodynamic therapy (PDT) for patients with local persistent and recurrent NPC.
Twenty-two patients with persistent and recurrent NPC (maximum tumor depth <10mm) under...
Interstitial photodynamic therapy (iPDT) can be an option in the management of locally recurrent base of tongue cancer after (chemo)radiation treatment. The purpose of the current study was to develop a technique to implant light sources into the tumor tissue.
Twenty patients with previously irradiated locally recurrent base of tongue cancers who w...
Extramedullary plasmacytomas (EMP) are rare plasma cell neoplasms that are mostly located in the mucosal surfaces of the upper aerodigestive tract. The standard treatment is radiotherapy (RT), with surgical resection reserved as salvage procedure. In this report a patient with a EMP, located in the nasopharynx and refractory to curative RT. Because...
While histopathology of excised tissue remains the gold standard for diagnosis, several new, non-invasive diagnostic techniques are being developed. They rely on physical and biochemical changes that precede and mirror malignant change within tissue. The basic principle involves simple optical techniques of tissue interrogation. Their accuracy, exp...
While histopathology of excised tissue remains the gold standard for diagnosis, several new, non-invasive diagnostic techniques are being developed. They rely on physical and biochemical changes that precede and mirror malignant change within tissue. The basic principle involves simple optical techniques of tissue interrogation. Their accuracy, exp...
While histopathology of excised tissue remains the gold standard for diagnosis, several new, non-invasive diagnostic techniques are being developed. They rely on physical and biochemical changes that precede and mirror malignant change within tissue. The basic principle involves simple optical techniques of tissue interrogation. Their accuracy, exp...
The complete surgical removal of disease is a desirable outcome particularly in oncology. Unfortunately much disease is microscopic and difficult to detect causing a liability to recurrence and worsened overall prognosis with attendant costs in terms of morbidity and mortality. It is hoped that by advances in optical diagnostic technology we could...
The indications of photodynamic therapy (PDT) of oral cavity and oropharynx neoplasms are not well defined. The main reason is that the success rates are not well established. The current paper analyzes our institutional experience of early stage oral cavity and oropharynx neoplasms (Tis-T2) to identify the success rates for each subgroup according...
The complete surgical removal of disease is a desirable outcome particularly in oncology. Unfortunately much disease is microscopic and difficult to detect causing a liability to recurrence and worsened overall prognosis with attendant costs in terms of morbidity and mortality. It is hoped that by advances in optical diagnostic technology we could...
In contrast to other interstitial applications of photodynamic therapy (PDT), optical guidance or monitoring in the head and neck is at a very early stage of development. The present paper reviews the use of optical approaches, in particular optical spectroscopy, that have been used or have the potential to guide the application of PDT. When consid...
This authoritative text presents the background, methodology and outcomes for Photodynamic Therapy (PDT) treatment of diseases of the head and neck. The author, an expert and pioneer in this field, discusses the indications for PDT treatment with their advantages and pitfalls. As PDT is an approved therapy for treatment of head and neck cancers in...
The objective of this study was to develop a light delivery and measurement device for photodynamic therapy (PDT) in the nasopharyngeal cavity, which achieves a homogeneous and reproducible fluence rate distribution to a target area and provides proper shielding of predefined risk areas.
A flexible silicone applicator was developed, incorporating l...
The objective of this study was to evaluate the performance of a dedicated light applicator for light delivery and fluence rate monitoring during Foscan-mediated photodynamic therapy of nasopharyngeal carcinoma in a clinical phase I/II study. We have developed a flexible silicone applicator that can be inserted through the mouth and fixed in the na...
The interaction of light with tissue and its use for medical purposes has been under
investigation for centuries. Since the early nineteen sixties, the development of novel
optical technology and advances in laser design/technology allowed a wide range of
innovative applications in many fields of medicine. For the majority of light applications...
Differential path-length spectroscopy (DPS) was used to determine the local optical properties of breast tissue in vivo. DPS measurements were made on healthy and malignant breast tissue using a fibre-optic needle probe, and were correlated to the histological outcome of core-needle biopsies taken from the same location as the measurements. DPS yie...
We propose a comprehensive protocol for the performance assessment of photon migration instruments. The protocol has been developed within the European Thematic Network MEDPHOT (optical methods for medical diagnosis and monitoring of diseases) and is based on five criteria: accuracy, linearity, noise, stability, and reproducibility. This protocol w...
We use spatially resolved diffuse remittance spectroscopy (DRS) for the measurement of absorption (mu(a)) and reduced scattering (mu(s)') coefficients of normal and malignant breast tissue in vivo during surgery. Prior to these measurements, the linearity of the measurement technique was evaluated on liquid optical phantoms. In addition, the reprod...
Photochemical and thermal methods are used for ablating Barrett's oesophagus (BO). The aim of this study was to compare 5-aminolevulinic acid induced photodynamic therapy (ALA-PDT) with argon plasma coagulation (APC) with respect to complete reversal of BO.
Patients with BO (32 no dysplasia and eight low grade dysplasia) were randomised to one of t...
In-vivo optical spectroscopy and the determination of tissue absorption and scattering properties have a central role in the development of novel optical diagnostic and therapeutic modalities in medicine. A number of techniques are available for the optical characterization of tissue in the visible near-IR region of the spectrum. An important consi...
The objective is derived from the need for a reliable absorption spectrum of lipids for component analysis of in vivo tissue spectra. NIR in vivo spectroscopy enables to derive the concentration of the key tissue constituents absorbing in the 600-1100 nm range, that is oxy- and deoxy- hemoglobin, water and lipids. Yet, although the first three cons...
Previous studies with PhotoDynamic Therapy (PDT) in bladder and bronchi have shown that due to scattering and reflection, the actually delivered fluence rate on the surface in a hollow organ can be significantly higher than expected. In this pilot study, we investigated the differences between the primary calculated and the actual measured fluence...
Diffuse-reflectance spectroscopy for measurement of the absorption and scattering coefficients of biological tissue produces reliable results for wavelengths from 650 to 1050 nm. Implicitly, this approach assumes homogeneously distributed absorbers. A correction factor is introduced for inhomogeneous distribution of blood concentrated in discrete c...
Fotodynamische therapie (PDT) is een behandelmodaliteit die toegepast wordt in de oncologie. Bij deze techniek wordt een lichtgevoelige
stof ingespoten en met een laser geactiveerd. De activatie leidt tot celdood en uiteindelijk tot necrose van het doelweefsel.
In de hoofd-halsoncologie wordt PDT gebruikt ter palliatie van incurabele carcinomen en...
To determine the optimal administered dose of meta-tetrahydroxyphenylchlorin (mTHPC) for intraoperative photodynamic therapy (IPDT) in resected malignant pleural mesothelioma (MPM). The primary objective of this combination treatment was to improve local tumor control.
Phase I/II dose escalation study.
Two Dutch cancer centers.
The study included 2...
In situ light dosimetry during photodynamic therapy (PDT) of malignant pleural mesothelioma (MPM) after tumour resection facilitates the delivery of a controlled light distribution to the inner thoracic surface. Illumination of the diaphragm-induced sinus, however, remains difficult. Our aim was to develop a wedge-shaped light applicator with incor...
Absorption and reduced scattering coefficients calculated from spatially resolved diffuse reflectance measurements are usually assumed to be unreliable for wavelengths lower than approximately 600 nm. A correction factor was developed for non-homogenous distribution of absorbers concentrated in discrete cylindrical blood vessels. The concept of an...
Effective photodynamic therapy (PDT) depends on the optimization of factors such as drug dose, drug-light interval, fluence rate and total light dose (or fluence). In addition sufficient oxygen has to be present for the photochemical reaction to occur. Oxygen deficits may arise during PDT if the photochemical reaction consumes oxygen more rapidly t...
Effective photodynamic therapy (PDT) depends on the optimization of factors such as drug dose, drug–light interval, fluence rate and total light dose (or fluence). In addition sufficient oxygen has to be present for the photochemical reaction to occur. Oxygen deficits may arise during PDT if the photochemical reaction consumes oxygen more rapidly t...
Absorption and reduced scattering coefficients calculated from spatially resolved diffuse reflectance measurements are usually assumed to be unreliable for wavelengths lower than approximately 600 nm. A correction factor was developed for non-homogenous distribution of absorbers concentrated in discrete cylindrical blood vessels. The concept of an...
The performance of an artificial neural network was evaluated as an alternative classification technique of autofluorescence spectra of oral leukoplakia, which may reflect the grade of tissue dysplasia. Twenty-two visible lesions of 21 patients suffering from oral leukoplakia and six locations on normal oral mucosa of volunteers were investigated w...
© 1999 Optical Society of America