Berrin Pehlivan - Academia.edu (original) (raw)

Papers by Berrin Pehlivan

Journal of stomatology, oral and maxillofacial surgery/Journal of stomatology oral & maxillofacial surgery, Mar 1, 2024

Journal of the Formosan Medical Association, Feb 1, 2024

Cancers, Sep 10, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Oral Diseases, May 8, 2023

PurposeTo investigate the predictive significance of hemoglobin (Hb) values in the incidence of r... more PurposeTo investigate the predictive significance of hemoglobin (Hb) values in the incidence of radiation‐induced trismus (RIT) in locally advanced nasopharyngeal carcinoma (LA‐NPC) patients who received concurrent chemoradiotherapy (C‐CRT).MethodsData of LA‐NPC patients were examined before and after C‐CRT and to confirm the presence of RIT, maximum mouth openings (MMO) were measured; RIT is defined as an MMO of ≤35 mm. All Hb values were derived from complete blood count tests obtained on the first day of C‐CRT. The receiver operating characteristic (ROC) curve analysis was used to scrutinize a possible connection between pre‐treatment Hb values and RIT status.ResultsTwo hundred and twenty three patients were included in the study and RIT was diagnosed in 46 (20.6%) patients. The Hb cutoff in ROC curve analysis that separated the patients into two groups was 12.05 g/dL [Area under the curve (AUC): 82.7%; sensitivity: 72.9%; and specificity: 71.3%]. RIT was significantly more prevalent in the Hb ≤ 12 g/dL group than in its counterpart (41.9% vs. 7.3%; p < 0.001). In multivariate analysis, Hb ≤ 12, anemia, pre‐C‐CRT MMO < 41.4 mm, and masticatory apparatus doseV58 Gy < 32% groups were found to be independently associated with significantly increased rates of RIT.ConclusionLow pre‐C‐CRT Hb and anemia status are novel biological markers that independently predict higher RIT rates in LA‐NPC undergoing C‐CRT.

Head & neck, May 12, 2023

ObjectivesTo explore how well a unique combination of hemoglobin‐to‐platelet ratio (HPR) and pret... more ObjectivesTo explore how well a unique combination of hemoglobin‐to‐platelet ratio (HPR) and pretreatment maximum mouth opening (MMO) predicts the prevalence of radiation‐induced trismus (RIT).Patients and methodsHPR and MMO cutoff values (0.54 and 40.7 mm) divided patients into two groups. To develop the novel HPR‐MMO index, four combinations of these factors were tested for predictive power: Group 1: HPR > 0.54 and MMO > 40.7 mm; Group 2: HPR ≤ 0.54 but MMO > 40.7 mm; Group 3: HPR > 0.54 but MMO ≤ 40.7 mm; Group 4: HPR ≤ 0.54 and MMO ≤ 40.7 mm.ResultsData of 198 patients with LA‐NPC was analyzed retrospectively. RIT rates for Groups 1 to 4 were 10.2%, 15.2%, 25%, and 59.4%. Groups 2 and 3 were merged to generate HPR‐MMO index because of statistically equivalent RIT rates: Low‐risk: HPR > 0.54 and MMO > 40.7 mm; Intermediate‐risk: HPR ≤ 0.54 but MMO > 40.7 mm or; HPR > 0.54 but MMO ≤ 40.7 mm; High‐risk: HPR ≤ 0.54 and MMO ≤ 40.7 mm. It was revealed that the low‐, high‐, and intermediate‐risk group's RIT rates; 10.2%, 59.4%, and 19.2%, respectively.ConclusionThe novel HPR‐MMO index may to classify LA‐NPC patients into low, intermediate, and high‐risk RIT groups.

Ege Tıp Dergisi, Mar 1, 2011

Proton therapy (PT) has been in clinical use since 1970, and 61,122 patients have been treated as... more Proton therapy (PT) has been in clinical use since 1970, and 61,122 patients have been treated as of the end of the 2008 in the world. The major advantage of PT over conventional radiatiotherapy is reduced side effects in the neighboring critical tissues, which in turn results in less treatment interruption and therefore better integration of RT with systemic chemotherapy. Indirectly, reducing late effects permits the radiation oncologist to dose escalation to a tumor which may potentially translate into higher tumor control rates. Additionally, patients experience a relatively better quality of life during and after PT. Proton therapy has been most extensively studied in the treatment of uveal melanomas and chordoma and chondrosarcoma patients. Other common tumors successfully treated with PT include central nervous system, head and neck, breast, lung, esophagus, prostate and liver tumors, and soft tissue/bone sarcomas. Proton therapy was conventinally delivered by passive scattering. Active scanning (AS) was developed at Paul Scherrer Institute. In addition to reducing scattered dose, intensity modulation and inverse planning are possible advantages offered by AS, therefore, most of the proton facilities in the world have voiced their interest in moving towards an AS system. Interest is growing in proton technology and newer PT facilities are being added to currently active ones all over the world.

Therapeutics and Clinical Risk Management, Apr 1, 2022

In a lack of similar research, we meant to retrospectively investigate the prognostic significanc... more In a lack of similar research, we meant to retrospectively investigate the prognostic significance of pre-chemoradiotherapy (C-CRT) platelet-to-albumin ratio (PAR) on the survival results of locally advanced unresectable pancreatic adenocarcinoma (LAPC) patients. Patients and Methods: The present analysis included 139 LAPC patients who received C-CRT in total. The utility of pre-C-CRT cutoff(s) reshaping survival data was explored using receiver operating characteristic (ROC) curve analysis. The primary and secondary objectives were the associations between PAR levels and overall survival (OS) and progression-free survival (PFS) outcomes. Results: At a median follow-up of 15.7 months (95% CI: 11.6-19.8), the overall cohort's median and 5-year OS rates were 14.4 months (95% CI: 11.8-17) and 14.7%, respectively, while the corresponding PFS rates were 7.8 months (95% CI: 6.5-9.1) and 11.2%. Because the ROC curve analysis found 4.9 as the optimal PAR cutoff for both OS and PFS [area under the curve (AUC): 75.4%; sensitivity: 72.4%; specificity: 70.3%], we divided the patients into two PAR cohorts: PAR<4.9 (N=60) and PAR≥4.9 (N=79). Comparative analysis per PAR group exhibited significantly worse OS (11.2 vs 18.6 months, and 9.8% vs 20.9% at 5 years, P=0.003) and DFS (7 vs 14.3 months, and 7.6% vs 16.2% at 5 years, P=0.001) with PAR≥4.9 versus PAR<4.9, respectively. In multivariate analysis, the N0 nodal status, CA 19-9≤90 U/mL, and PAR<4.9 were found to be independent predictors of improved OS and PFS. Conclusion: The pre-C-CRT high PAR (≥4.9) robustly and independently prognosticated significantly worse OS and PFS results in inoperable LAPC patients who underwent definitive C-CRT.

Journal of Neurosurgical Sciences, Mar 1, 2010

Prognostic factors which affect treatment results of glioblastoma multiforme (GBM; WHO Grade IV) ... more Prognostic factors which affect treatment results of glioblastoma multiforme (GBM; WHO Grade IV) patients has been investigated in many researches. For these patients determination of prognostic factors helps generating multimodal therapy protocols. For this purpose, in the Baskent University Medical School, Neurosurgery Clinic, Adana Medical Research Center, specific characteristics of GBM patients who have surgery retrospectively investigated and factors which affect prognosis has been determined. Between January 2005 and January 2009, 59 patients (25 female, 34 male) who have GBM have been evaluated retrospectively. Mean follow-up period was 27.4 (+/-17.3) months. Headache (66.1%) was the most seen symptom. Time of diagnosis was 1-2 months for most of the patients (54.2%). Fifty-nine patients had 67 operations totally. Preoperative Karnofski Performance Scale (KPS) was &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=70 for 43 operations, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;or=70 for 24 operations. Frontal lobe was the most involved part of the tumor,and biggest tumor has the diameter of 4.8 (+/-1.42) cm. Forty gross total resection, 26 subtotal resection and 1 lobectomy were performed. Postoperatively for 41 operations KPS&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=70, for 26 operations KPS&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;or=70. After surgery 44 patients had radiation therapy (RT). Eighteen patients had only adjuvant RT, 26 patients had temozolomide (TMZ) treatment used at the same time with RT combination therapy (CombT with TMZ) and 6 cures adjuvant TMZ concomitant therapy (ConcT with TMZ). Median survival and prognostic factors of 42 GBM patients was calculated with multivariable and univariable analysis. Median survival was 8 (+/-1.5) months for patients who died. One year survival was 83.3% and two-year survival 16.7%. After treatment, relapse occurred in 12 patient at the site of the tumor and these patients had been reoperated. After univariate statistical analysis preoperative KPS was &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=70 (P=0.0000) , postoperative KPS 2 was &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=70 (P=0.0000), type of tumor resection (P=0.00002), multiple operations (P=0.001), adjuvant RT (P=0.0000) and ConcT with adjuvant TMZ (P=0.0000) were all positive prognostic factors which extend the survival. After multivariate analysis, post operative KPS was &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=70 (P=0.003; OR:0.89; % 95 CI:0.83-0.96), type of resection (P=0.055; OR:0.37; % 95 CI:0.13-0.12) and multiple operations (P=0.042; OR:2.65; % 95 CI:1.03-6.82) were independent prognostic factors. When independent prognostic factors were examined ,median survival found out 7.8 months longer fort he patients whose postoperative KPS were &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=70, 5.7 months longer for the patients who had radical resection, 6.6 months longer for the patients who had multiple operations. Although patients who had ConcT with adjuvant TMZ had 1.7 months longer survival compared to patients who had only adjuvant RT, it was not determined as an independent prognostic factor.

Strahlentherapie Und Onkologie, Aug 11, 2023

Oral Diseases, Nov 21, 2022

ObjectiveTo investigate the link between pretreatment neutrophil‐to‐lymphocyte ratio(NLR) and the... more ObjectiveTo investigate the link between pretreatment neutrophil‐to‐lymphocyte ratio(NLR) and the incidence of radiation‐induced trismus(RIT) in parotid gland cancers(PGC) patients after postoperative radiotherapy(PORT).MethodData of PGC patients who had oral examinations before and after PORT were reviewed retrospectively. We comprised patients who had maximum mouth opening (MMO) assessments before and after PORT and complete blood count test on the first day of PORT. MMO of ≤35 mm was considered as RIT. The receiver operating characteristic (ROC) curve analysis was used to search for an ideal NLR threshold value that might be linked to RIT rates.ResultsFifty‐one patients were included, with a RIT incidence of 15.7%. The NLR cutoff that showed a link with the prevalence of RIT in the ROC curve analysis was 2.7[Area under the curve (AUC):82.0%; sensitivity:87.5%; specificity:74.4%]. The patients were divided into groups based on this value:Group 1: NLR≤2.7 (N = 34) and;NLR >2.7 (N = 17). In comparative analysis, the incidence of RIT was found to be statistically higher in the NLR >2.7 than counterpart (35.2%vs.5.8%;rs:0.79; p < .001). Also, a mean temporomandibular joint dose ≥51.0Gy was linked to increased RIT rates (p < .001).ConclusionThis study showed that high pre‐PORT NLR levels were a robust and independent predictor of significantly elevated rates of RIT.

Exon Publications eBooks, Jan 3, 2023

Metastasis of solid tumors to the brain occurs in about 30% of cases. Surgery and whole-brain rad... more Metastasis of solid tumors to the brain occurs in about 30% of cases. Surgery and whole-brain radiotherapy have been the standard treatments with very limited success rates. As a result of the unsatisfactory local control and longterm survival outcomes, stereotactic radiosurgery has been used as an alternative to surgery and whole-brain radiotherapy, or to improve the outcomes in conjunction with other treatments. However, stereotactic radiosurgery does not produce the desired survival results despite the striking increases in local control rates, primarily because of deaths attributed to extracranial systemic disease progression or unavoidably fatal distant brain recurrences. Lately, immunotherapy has become Kucuk A et al. 58 a part, or mainstay, of treatment algorithms for many cancer types. Several authors have proposed the integration of stereotactic radiosurgery and immunotherapy for the treatment of brain metastasis. This chapter evaluates the efficacy and safety of combining novel immunotherapeutics with traditional stereotactic radiosurgery for the treatment of brain metastasis.

Exon Publications eBooks, Oct 28, 2022

Radiation-induced trismus is a devastating side effect of radiotherapy in patients with head and ... more Radiation-induced trismus is a devastating side effect of radiotherapy in patients with head and neck cancers. It hampers daily activities like eating, speaking, chewing, swallowing, and oral hygiene routines. Radiation-induced trismus also negatively affects social interactions, psychological wellbeing, and lowers the quality of life of patients. The most common method for determining radiationinduced trismus is to measure the 'maximum mouth opening'. Different cutoff Somay E et al. 24 values for maximum mouth opening have been employed in studies that assessed radiation-induced trismus, including 40 mm, 35 mm, 30 mm, and 20 mm. The impact and prevalence of radiation-induced trismus are not fully understood because there is no common and reliable objective measure to determine cutoff values of maximum mouth opening. Additionally, regardless of the pretreatment measures, a standard cutoff is applied to all patients, where a change may be substantial for one patient but not necessarily for another. These discrepancies may cause certain patients' conditions to be overstated or understated, misdirecting their prophylactic or therapeutic interventions. This chapter highlights the current concepts and controversies of the definitions of radiation-induced trismus, and the possible challenges in managing radiation-induced trismus because of the varied definitions.

International journal of advanced research, Sep 30, 2019

American Journal of Clinical Oncology, Jun 1, 2012

BACKGROUND: To evaluate pathologically confirmed incidence of pseudoprogression and its impact on... more BACKGROUND: To evaluate pathologically confirmed incidence of pseudoprogression and its impact on survival in glioblastoma multiforme (GBM) patients treated with radiotherapy and concurrent temozolomide (TMZ), followed by 6 months of TMZ maintenance therapy. MATERIALS AND METHODS: Sixty-three patients with histologic proof of GBM underwent 60 Gy (2 Gy/fr, 30 fractions) of brain radiotherapy concurrent with continuous 75 mg/m/d TMZ, followed by 6 cycles of maintenance TMZ (200 mg/m/d for 5 d, every 28 d). Response assessment was performed by magnetic resonance imaging every 2 months. All patients with radiologic doubt of early tumor progression (≤6 mo) underwent salvage surgery. RESULTS: All patients underwent surgical resection. Gross total, subtotal resection, and biopsy were performed in 17 (27.0%), 32 (51.6%), and 14 (21.4%) patients, respectively. Lesion enlargement on first follow-up magnetic resonance imaging evidenced in 28 (44.4%) patients. Salvage pathologies revealed pseudoprogression in 12 of 28 (42.8%) patients corresponding to an overall pseudoprogression rate of 19%. Survival analysis revealed that patients with pseudoprogression had superior overall and progression-free survival rates at both 1 and 2 years (P<0.05 for each, respectively). CONCLUSIONS: Current results indicates the urgency of need for novel imaging techniques and/or biochemical marker(s) that can better distinguish pseudoprogression from true progression to avoid unnecessary and potentially harmful surgical interventions in almost half of the radiologically progressive GBM patients. Our additional observation which suggests better survival for patients with pseudoprogression warrants to be studied in larger patient cohorts.

Cancer Control, Apr 1, 2023

Journal of Clinical Medicine, Apr 21, 2023