1,721,066 research outputs found
Angiosarcoma after adjuvant radiotherapy in high-risk squamous cell carcinoma of the vulva: A case report
No full textSquamous cell carcinoma of the vulva represents 3-5% of gynecological cancers. The incidence is higher in postmenopausal patients; the mean age of women with vulvar cancer is between 64 and 70 years. Radiotherapy plays an increasing role in the treatment of high-risk squamous cell carcinoma of the vulva; associated with surgery it significantly improves prognosis but is also associated with serious late side-effects, such as secondary malignancies. We describe a case of a 75-year-old woman who underwent deep total vulvectomy with inguinal-femoral lymphadenectomy for high-risk, keratinizing variant HPV-negative, squamous cell carcinoma of the vulva, followed by adjuvant concomitant chemo-radiotherapy, at the University Hospital of Pisa in February 2013. Five years later she developed a very large angiosarcoma in the right abdominal wall, at the edge of the previous radiotherapy field, and underwent radical surgery. After four months, she developed bone metastasis of angiosarcoma, also treated with surgery. This experience shows that the use of new technologies allows the delivery of high doses of radiotherapy, significantly correlated with a better prognosis, but also associated with fortunately rare morbidity, such as radiation-induced angiosarcoma. Due to the presence of long, mostly post-menopausal survivors among irradiated patients, screening for second malignancies must be developed for selected high-risk survivor groups
EP-1227 The impact of first MR in clinical decision making of patients with HGG treated with RTCT
Full text linkPurpose or Objective
Standard up-front therapy of high grade glioma (HGG) is focused on the so called Stupp protocol, that includes surgical resection followed by radiotherapy (RT) combined with concomitant and adjuvant chemotherapy with temozolomide (TMZ). As supported by several international guidelines, disease assessment is performed using magnetic resonance (MR) one month since the end of RT and then every 3 months: in case of tumour progression the administration of temozolomide (the most active agent against glioma) is interrupted and salvage therapy or best supportive care are recommended. The aim of this study is to investigate in a retrospective manner the real value of first MR following RT and its relevance in clinical decision making about up-front therapy.
Material and Methods
Between April 2005 and July 2017, data of 78 patients (pts) with a proven diagnosis of HGG and treated with Stupp protocol at the University Hospital of Pisa were collected. Tumor progression was defined according to Mac-Donald’s Criteria. Considering the potential presence of pseudoprogression (PSP) and the evolutionary pattern of the suspected recurrences, lesions suggestive for tumor progression inside the radiotherapy field were investigate with a new MR after 6-8 weeks. Otherwise, the presence of new lesions outside the radiotherapy field was interpreted as disease progression (PD) and patient’s therapy was changed. Presence or absence of symptoms, extent of surgery and MGMT methylation status were recorded.
Results
The first MR after RT-CT evidenced infield progression (interpreted as PSP) in 16 pts (20,5%) and outfield progression in 8 (10.2%).Three out of 8 patients with outfield progression were symptomatic for the tumor growth. The second MRI confirmed the presence of PSP in 10 pts out of 16 pts whereas in 6 patients a true progression (PD) was present since the first MR.
Conclusion
In absence of symptoms, the first MR after radiochemotherapy influenced clinical decision making (sending the patients to further salvage therapy or BSC) only in 5 out of 78 patients (6.4%). In 72 patients, even in presence of radiological signs suggestive for disease progression inside the RT field, clinical decision making did not change. Further studies involving a higher number of patients are required in order to confirm our findings
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Set-up errors in head and neck cancer treated with IMRT technique assessed by cone-beam computed tomography: a feasible protocol
Full text linkPURPOSE:
To investigate set-up errors, suggest the adequate planning target volume (PTV) margin and image-guided radiotherapy frequency in head and neck (H&N) cancer treated with intensity-modulated radiotherapy (IMRT) assessed by kV cone-beam computed tomography (CBCT).
METHODS:
We analyzed 360 CBCTs in 60 patients with H&N cancer treated with IMRT. The target delineation was contoured according to ICRU62. PTVs were generated by adding a 3-5 mm margin in all directions to the respective clinical target volumes. The kV CBCT images were obtained at first three days of irradiation and weekly thereafter. The overall mean displacement, range, systematic (∑) and random (σ) errors were calculated. Adequate PTV margins were calculated according to the van Herk formula (2.5∑ + 0.7r).
RESULTS:
The mean of set-up errors was less than 2 mm in any direction. The overall frequency of set-up displacements greater than 3 mm was 3.9% in medial-lateral (ML) direction, 8% in superior-inferior (SI) direction, and 15.5% in anterior-posterior (AP) direction. The range of translations shifts was 0-9 mm in ML direction, 0-5 mm in SI direction and 0-10 mm in AP direction, respectively. After systematic set-up errors correction, the adequate margin to overcome the problem of set-up errors was found to be less than 3 mm.
CONCLUSION:
Image-guided kV CBCT was effective for the evaluation of set-up accuracy in H&N cancer. The kV CBCT at first three fractions and followed-by weekly appears adequate for reducing significantly set-up errors in H&N cancer treated with IMRT technique. Finally, 3-5 mm PTV margins appear adequate and safe to overcome the problem of set-up errors
Single-fraction flattening filter-free volumetric modulated arc therapy for lung cancer: Dosimetric results and comparison with flattened beams technique
No full textPurpose: To report on single-fraction stereotactic body radiotherapy (RT) (SBRT) with flattening filter (FF)-free (FFF) volumetric modulated arc therapy (VMAT) for lung cancer and to compare dosimetric results with VMAT with FF. Methods and materials: Overall, 25 patients were treated with 6-MV FFF VMAT (Varian TrueBeam STx LINAC) to a prescribed dose of 24 Gy in a single fraction. Treatment plans were recreated using FF VMAT. Dose-volume indices, monitor units (MU), and treatment times were compared between FFF and FF VMAT techniques. Results: Dose constraints to PTV, spinal cord, and lungs were reached in FFF and FF plans. In FFF plans, average conformity index was 1.13 (95% CI: 1.07 to1.38). Maximum doses to spinal cord, heart, esophagus, and trachea were 2.9 Gy (95% CI: 0.4 to 6.7 Gy), 0.8 Gy (95% CI: 0 to 3.6 Gy), 3.3 Gy (95% CI: 0.02 to 13.9 Gy), and 1.5 Gy (95% CI: 0 to 4.9 Gy), respectively. Average V7 Gy, V7.4 Gy, and mean dose to the healthy lung were 126.5 cc (95% CI: 41.3 to 248.9 cc), 107.3 cc (95% CI: 18.7 to 232.8 cc), and 1.1 Gy (95% CI: 0.3 to 2.2 Gy), respectively. No statistically significant differences were found in dosimetric results and MU between FF and FFF treatments. Treatment time was reduced by an average factor of 2.31 (95% CI: 2.15 to 2.43) from FF treatments to FFF, and the difference was statistically significant. Conclusions: FFF VMAT for lung SBRT provides equivalent dosimetric results to the target and organs at risk as FF VMAT while significantly reducing treatment time. (C) 2016 American Association of Medical Dosimetrists
Patterns of Failures and Clinical Outcome of Patients with Early-Stage, High-Risk, Node-Negative Endometrial Cancer Treated with Surgery Followed by Adjuvant Platinum-Based Chemotherapy and Vaginal Brachytherapy
No full textObjective: To assess the clinical outcome of patients with high-risk early-stage endometrial cancer and negative pelvic nodes who received adjuvant platinum-based chemotherapy plus vaginal brachytherapy (VBT). Methods: This investigation assessed 80 patients who underwent hysterectomy, bilateral salpingo-oophorectomy, and pelvic lymphadenectomy for stage Ib-II, grade 2-3 endometrioid (n = 43) or stage Ia-II nonendometrioid (n = 37) endometrial cancer. Results: Five-year local control rate, 5-year disease-free survival, and 5-year overall survival were 97, 87, and 97%, respectively, for endometrioid carcinoma, and 66, 50, and 72%, respectively, for nonendometrioid carcinoma. Conclusions: This retrospective study appears to show that adjuvant platinumbased chemotherapy plus VBT achieve very good results in endometrioid carcinoma. This combined treatment seems to be less effective in nonendometrioid carcinoma
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