Institute of Radiation Oncology

Haifa, Israel

Institute of Radiation Oncology

Haifa, Israel

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Amit M.,Head and Neck Cancer Center | Amit M.,Clinical Research Institute at Rambam | Na'Ara S.,Head and Neck Cancer Center | Na'Ara S.,Clinical Research Institute at Rambam | And 8 more authors.
Head and Neck | Year: 2016

Background A positive margin is among the most significant factors that affects the outcome in head and neck squamous cell carcinoma (SCC). The purpose of this study was to compare the negative margin rates between 2 methods of intraoperative margin assessment in patients with oral cavity SCC. Methods A prospective, randomized controlled trial comparing 2 methods of intraoperative margin assessment: specimen-driven margins and patient-driven margins. Results The final analysis included 71 patients, 20 (29%) in the patient-driven margin arm. Frozen section analysis revealed positive/close surgical margins that led to an extension of the surgical resection in 22 of 51 patients (43%) in the specimen-driven margin arm, and 2 of 20 patients (10%) in the patient-driven margin arm (p =.01). After final pathological analysis, the wide negative margin rate was 84% in the specimen-driven margin arm, compared to 55% in the patient-driven margin arm (p =.02). Extension of the surgical resection prevented escalation of adjuvant treatment in 19 patients (38%) in the specimen-driven margin arm and 10% in the patient-driven margin arm. Conclusion Specimen derived margin assessment led to significant improvement in the rate of negative margins. © 2015 Wiley Periodicals, Inc..


Lohse I.,University of Zürich | Lang S.,University of Zürich | Hrbacek J.,University of Zürich | Scheidegger S.,ZHAW Zurich University of Applied Sciences | And 5 more authors.
Radiotherapy and Oncology | Year: 2011

Purpose: To investigate if there is a statistically significant difference in cancer cell survival using a high dose per pulse flattening filter-free (FFF) beam compared to a standard flattened beam. Material and methods: To validate the radiobiological effect of the flattened and FFF beam, two glioblastoma cell lines were treated with either 5 or 10 Gy using different dose rates. Dose verification was performed and colony formation assays were carried out. To compare the predictability of our data, radiobiological models were included. Results: The results presented here demonstrate that irradiation of glioblastoma cell lines using the FFF beam is more efficient in reducing clonogenic cell survival than the standard flattened beam, an effect which becomes more significant the higher the single dose. Interestingly, in our experimental setting, the radiobiological effect of the FFF beam is dependent on dose per pulse rather than on delivery time. The used radiobiological models are able to describe the observed dose rate dependency between 6 and 24 Gy/min. Conclusion: The results presented here show that dose per pulse might become a crucial factor which influences cancer cell survival. Using high dose rates, currently used radiobiological models as well as molecular mechanisms involved urgently need to be re-examined. © 2011 Elsevier Ireland Ltd. All rights reserved.


Zimmermann F.,University of Basel | Wulf J.,Institute of Radiation Oncology | Lax I.,Karolinska University Hospital | Nagata Y.,Hiroshima University | And 3 more authors.
Frontiers of Radiation Therapy and Oncology | Year: 2010

For patients with early stage non-small cell lung cancer (NSCLC) unsuitable for resection local high-dose radiotherapy is the treatment of choice. In modern series even with escalated conformal radiotherapy local control rates of about 55% remain disappointing. Within the last years, stereotactic radiotherapy has been shown an effective treatment approach for early stage malignant lung tumors, combining the accurate focal dose delivery by stereotactic techniques with the biological advantages of dose escalated hypofractionated radiotherapy. Typical treatment regimens include three to five fractions over 1-2 weeks or 1 single fraction as radiosurgery. With adequate staging procedures including FDG-PET-CT scan and a low probability of subclinical involvement of unsuspicious locoregional lymph nodes, the concept is to irradiate the primary T1/2 tumor alone. Recent data report local control rates of up to 90%, with favorable results especially for patients in good general condition. Less than 10% of all patients develop isolated tumor recurrences in regional lymph nodes. Three-year survival is significantly improved to more than 80% when biological effective doses of more than 100 Gy are applied to patients in good conditions. Systemic tumor recurrence still is a major problem, making an additional systemic chemotherapy interesting for selected patients after hSRT, such as those younger than 75 years. © 2010 S. Karger AG.


PubMed | Institute of Radiation Oncology
Type: Journal Article | Journal: Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al] | Year: 2011

To present the feasibility and results of accelerated radiotherapy with concomitant boost technique (69.5 Gy/5 weeks) in the treatment of locally advanced head and neck cancer.A total of 65 patients were treated between June 2006 and August 2009. The distribution of clinical stages was as follows: II 11%, III 23%, IV 61%, and not defined 5%.The median follow-up was 30.5 months. The treatment plan was completed in 94% of patients. Patients were treated using the conformal or intensity-modulated radiotherapy (IMRT) technique. The median overall treatment time was 37 days (13-45 days). The mean radiotherapy dose was 68.4 Gy (16-74 Gy). Overall survival was 69% after 2 years. Disease-free survival was 62% after 2 years. Acute toxicity grade 3(RTOG scale) included mucositis (grade 3: 42.6%), pharynx (grade 3: 42.3%), skin (grade 3: 9.5%), larynx (grade 3: 4%), while late toxicity affected skin (grade 3: 6.25%) and salivary glands (grade 3: 3.7%).Accelerated radiotherapy with concomitant boost technique is feasible in patients with locally advanced head and neck cancer, has an acceptable toxicity profile, and yields promising treatment results.


PubMed | Rambam Healthcare Campus, Institute of Radiation Oncology, Tel Aviv Medical Center and Head and Neck Cancer Center
Type: | Journal: Head & neck | Year: 2016

A positive margin is among the most significant factors that affects the outcome in head and neck squamous cell carcinoma (SCC). The purpose of this study was to compare the negative margin rates between 2 methods of intraoperative margin assessment in patients with oral cavity SCC.A prospective, randomized controlled trial comparing 2 methods of intraoperative margin assessment: specimen-driven margins and patient-driven margins.The final analysis included 71 patients, 20 (29%) in the patient-driven margin arm. Frozen section analysis revealed positive/close surgical margins that led to an extension of the surgical resection in 22 of 51 patients (43%) in the specimen-driven margin arm, and 2 of 20 patients (10%) in the patient-driven margin arm (p = .01). After final pathological analysis, the wide negative margin rate was 84% in the specimen-driven margin arm, compared to 55% in the patient-driven margin arm (p = .02). Extension of the surgical resection prevented escalation of adjuvant treatment in 19 patients (38%) in the specimen-driven margin arm and 10% in the patient-driven margin arm.Specimen derived margin assessment led to significant improvement in the rate of negative margins. 2015 Wiley Periodicals, Inc. Head Neck 38: E1803-E1809, 2016.

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