Handan Tokmak

Prof. Dr. Handan Tokmak

Nuklear Medicine and Molecular Imaging, University of Health Sciences Prof. Dr. Cemil Tascioglu Hospital, Istanbul, İstanbul, Turkey (Türkiye)
orcid

Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 June 2018 in The Lancet
Verified
Journal Article
Open access
MVMaxime J M van der Valk
Maxime J M van der Valk
DHDenise Hilling
Denise Hilling
EBEsther Bastiaannet
Esther Bastiaannet
EKElma Meershoek-Klein Kranenbarg
Elma Meershoek-Klein Kranenbarg
GBGeerard Beets
Geerard Beets
DZDavid D E Zimmerman
David D E Zimmerman
The strategy of watch and wait (W&W) in patients with rectal cancer who achieve a complete clinical response (cCR) after neoadjuvant therapy is new and offers an opportunity for patients to avoid major resection surgery. However, evidence is based on small-to-moderate sized series from specialist centres. The International Watch & Wait Database (IWWD) aims to describe the outcome of the W&W strategy in a large-scale registry of pooled individual patient data. We report the results of a descriptive analysis after inclusion of more than 1000 patients in the registry. Participating centres entered data in the registry through an online, highly secured, and encrypted research data server. Data included baseline characteristics, neoadjuvant therapy, imaging protocols, incidence of local regrowth and distant metastasis, and survival status. All patients with rectal cancer in whom the standard of care (total mesorectal excision surgery) was omitted after neoadjuvant therapy were eligible to be included in the IWWD. For the present analysis, we only selected patients with no signs of residual tumour at reassessment (a cCR). We analysed the proportion of patients with local regrowth, proportion of patients with distant metastases, 5-year overall survival, and 5-year disease-specific survival. Between April 14, 2015, and June 30, 2017, we identified 1009 patients who received neoadjuvant treatment and were managed by W&W in the database from 47 participating institutes (15 countries). We included 880 (87%) patients with a cCR. Median follow-up time was 3·3 years (95% CI 3·1-3·6). The 2-year cumulative incidence of local regrowth was 25·2% (95% CI 22·2-28·5%), 88% of all local regrowth was diagnosed in the first 2 years, and 97% of local regrowth was located in the bowel wall. Distant metastasis were diagnosed in 71 (8%) of 880 patients. 5-year overall survival was 85% (95% CI 80·9-87·7%), and 5-year disease-specific survival was 94% (91-96%). This dataset has the largest series of patients with rectal cancer treated with a W&W approach, consisting of approximately 50% data from previous cohort series and 50% unpublished data. Local regrowth occurs mostly in the first 2 years and in the bowel wall, emphasising the importance of endoscopic surveillance to ensure the option of deferred curative surgery. Local unsalvageable disease after W&W was rare. European Registration of Cancer Care financed by European Society of Surgical Oncology, Champalimaud Foundation Lisbon, Bas Mulder Award granted by the Alpe d'Huzes Foundation and Dutch Cancer Society, and European Research Council Advanced Grant.
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1 February 2014 in International Journal of Infectious Diseases
Verified
Journal Article
Open access
Handan TokmakHandan Tokmak
Handan Tokmak
Onder ErgonulOnder Ergonul
Onder Ergonul
ODOnur Demirkol
Onur Demirkol
MCMustafa Cetiner
Mustafa Cetiner
BFBurhan Ferhanoglu
Burhan Ferhanoglu
Fever of unknown origin (FUO) remains one of the most compelling diagnostic issues in medicine. We aimed to evaluate the potential clinical contribution of 18-fluoro-2-deoxyglucose positron emission tomography/computed tomography ((18)F-FDG-PET/CT) in the identification of the underlying cause of FUO. Fifty consecutive patients (27 men and 23 women; age range 16-88 years) with FUO based on the revised definition criteria were included in the study. A diagnostic protocol including biochemistry, histopathology, and microbiological tests was performed and the patients were followed up. FDG-PET was performed in 25 of the 50 patients (12 males and 13 females; age range 16-88 years) in order to determine the etiology of the patient's fever. PET-CT images were obtained with the Gemini Philips TF (18)F-FDG-PET/CT camera after a 60-min 'standard uptake' period following an injection of a mean 330 MBq (range 290-370 MBq) intravenous (18)F-FDG. A total of 21 patients were available for analysis of the diagnostic contribution of PET/CT (two patients were undiagnosed and two had non-contributory PET/CT findings). (18)F-FDG-PET/CT was able to precisely detect the cause of fever in 60% of the cases (n=15). The accuracy, sensitivity, and specificity of this imaging modality were 90.5%, 93.8%, and 80%, respectively. Among the cases with a true-positive (18)F-FDG-PET/CT finding (i.e., 15 cases), the identified underlying causes of FUO included localized infection (n=7), non-infective inflammatory process (n=5), and malignancy (n=3). Further studies to confirm the high diagnostic yield of (18)F-FDG-PET/CT observed in the present study would lend support to the inclusion of this imaging modality in the initial diagnostic work-up of patients with suspected FUO.

10 May 2025 in Journal of Clinical Oncology
Verified
Journal Article
Open access
LFLaura M. Fernandez
Laura M. Fernandez
GJGuilherme P. São Julião
Guilherme P. São Julião
Carlos Cerdán SantacruzCarlos Cerdán Santacruz
Carlos Cerdán Santacruz
ARAndrew G. Renehan
Andrew G. Renehan
ÓCÓscar Cano-Valderrama
Óscar Cano-Valderrama
ZZZhen Zhang
Zhen Zhang
PURPOSE: Organ preservation has become an attractive alternative to surgery (total mesorectal excision [TME]) among patients with rectal cancer after neoadjuvant therapy who achieve a clinical complete response (cCR). Nearly 30% of these patients will develop local regrowth (LR). Although salvage resection is frequently feasible, there may be an increased risk for development of subsequent distant metastases (DM). The aim of this study is to compare the risk of DM between patients with LR after Watch and Wait (WW) and patients with near-complete pathologic response (nPCR) managed by TME at the time of reassessment of response. METHODS: Data from patients enrolled in the International Watch & Wait Database (IWWD) with cCR managed by WW and subsequent LR were compared with patients managed by TME (with ≤10% cancer cells—nPCR) from the Spanish Rectal Cancer Project (VIKINGO project). The primary end point was DM-free survival at 3 years from decision to WW or TME. The secondary end point was possible risk factors associated with DM. RESULTS: Five hundred and eight patients with LR were compared with 893 patients with near-complete response after TME. Overall, DM rate was significantly higher among LRs (22.8% v 10.2%; P ≤ .001). Independent risk factors for DM included LR ( v TME at reassessment; P = .001), ypT3-4 status ( P = .016), and ypN+ status ( P = .001) at the time of surgery. 3-year DM-free survival was significantly worse for patients with LR (75% v 87%; P = .001). When stratified for pathologic stage, patients with LR did significantly worse through all stages ( P ≤ .009). CONCLUSION: Patients with LR appear to have a higher risk for subsequent DM development than patients with nPCR managed by TME at restaging irrespective of final pathology. Leaving the primary undetectable tumor in situ until development of LR may result in worse oncologic outcomes.

1 June 2005 in Cancer Biotherapy and Radiopharmaceuticals
Verified
Journal Article
Closed access
CTCüneyt Türkmen
Cüneyt Türkmen
BZBülent Zülflkar
Bülent Zülflkar
ÖTÖmer Taşer
Ömer Taşer
Handan TokmakHandan Tokmak
Handan Tokmak
ÖKÖnder Kílíčoǧlu
Önder Kílíčoǧlu
SCSema Cantez
Sema Cantez
The aim of this study was to evaluate the efficacy of 90Y and 186Re radiosynovectomy in patients with hemophilic synovitis. Radiosynovectomy was performed in 32 joints of 20 patients with hemophilic synovitis by using 90Y citrate colloid in the knee and 186Re sulfide colloid in the elbow, shoulder, and ankle. The indication for radiosynovectomy was the continuous presence of intra-articular blood or effusion and three or more hemorrhages into the same joint within the last 6 months. Response to therapy was first assessed at the 4th month with blood-pool imaging. Patients were followed up by clinical evaluation based on assessments of joint-bleeding frequency, using range of motion measurements at 6-month intervals for an average of 1 year (range, 9-15 months). A marked decrease (an 80%-100% decrease) in bleeding episodes was seen in 24 of 32 (75%) joints, a moderate decrease (51%-79% decrease) in 1 (9%) joint, and a mild decrease (30%-50%) in 3 (13%) joints. Frequency of intra-articular bleeding after treatment was unchanged in only 13% of the joints. The number of hemarthroses significantly decreased after therapy (p < 0.05). The mean bleeding frequency of the joints were 1.7 +/- 0.9 and 0.3 +/- 0.7 per month before and after therapy, respectively. The ratios of joints which had marked improvement after therapy were 86% in the ankle, 73% in the elbow, and 58% in the knee. There was no significant difference between percent joint range of motion limitations measured before and after therapy (p > 0.05). The correlation between therapeutic outcome (in terms of joint bleeding) and the difference of pre- and posttherapeutic blood-pool indices were significant (r = 0.594; p < 0.05), while the correlation between therapeutic outcome and pretherapeutic radiologic scale and pretherapeutic blood-pool indices were not significant (r = 0.095; p > 0.05; r = -0.089; p > 0.05, respectively). Radiosynovectomy is a simple but quite effective and efficient procedure in limiting the frequency of joint hemorrhage in patients with hemophilia. Blood-pool imaging may be an objective means for monitoring therapy response in these patients.
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1 January 2006 in Renal Failure
Verified
Journal Article
Closed access
Handan TokmakHandan Tokmak
Handan Tokmak
AMAyşe Mudun
Ayşe Mudun
CTCuneyt Türkmen
Cuneyt Türkmen
YŞYasemin Şanli
Yasemin Şanli
SCSema Cantez
Sema Cantez
SBSemra Bozfakioğlu
Semra Bozfakioğlu
While continuous ambulatory peritoneal dialysis (CAPD) offers several advantages over hemodialysis in patients with end-stage renal disease, several complications have been recognized. The intraperitoneal instillation of dialysate increases intra-abdominal pressure and consequently predisposes the patient to leaks and herniations through defects in the abdominal wall. The use of an intraperitoneal radiolabeled colloid has been previously described to image entities such as hernias, patent processus vaginalis, abdominal wall, and diaphragmatic leakage. This study shows a simple, non-invasive method of determining the site of dialysate leak and its importance to assist further patient management. There has been a continuing increase in the number of end stage renal disease patients maintained on chronic peritoneal dialysis (CPD). Many patients choose CPD as their preferred chronic dialysis treatment, though approximately 20% of patients who drop out transfer to hemodialysis annually.[1] Although peritonitis remains the major reason for transfer to hemodialysis, other factors such as exit site infections, catheter-related problems, abdominal wall and inguinal hernias, loss of ultrafiltrations, and poor clearance contribute to CPD technique failure.[2] In order to permit the continuation of long-term therapy with CPD, these complications should be resolved. Routine laboratory evaluation or physical examination can detect some CPD-related problems; however, some patients require more complicated investigations to evaluate their problems properly.
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1 January 2014 in World Journal of Surgical Oncology
Verified
Journal Article
Open access
PDF file
Handan TokmakHandan Tokmak
Handan Tokmak
KKKerim Kaban
Kerim Kaban
MMMahmut Muslumanoglu
Mahmut Muslumanoglu
MDMeral Demirel
Meral Demirel
SASukru Aktan
Sukru Aktan
In patients with recurrent or second primary ipsilateral breast cancer, axillary staging is the key factor in locoregional control and a strong prognostic characteristic. The efficient evaluation of lymphatic drainage of re-sentinel lymph node biopsies (re-SLNBs) has remained a challenge in the management of ipsilateral primary or recurrent breast cancer patients who are clinically lymph node negative. This study explores whether a SLNB for patients with primary or recurrent breast cancer is possible after previous axillary surgery. It evaluates potential reasons for mapping failure that might be associated with patients in this group.
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