Silvia Maria Anglesio

A case of primary mediastinal Ewing's sarcoma /primitive neuroectodermal tumor presenting with initial compression of superior vena cava

Ewings sarcomas and peripheral primitive neuroectodermal tumors (ES/PNETs) are high grade malignant neoplasms. These malignancies are characterized by a chromosome 22 rearrangement, arise from bone or soft tissue, predominantly affect children and young adults, and are grouped in the Ewing family of tumors. Multimodality treatment programs are the treatment of choice. Primary localization of ES/PNET in the mediastinum is extremely rare. We describe a case of ES/PNET presenting as a mediastinal mass with tracheal compression and initial signs of superior vena cava in a 66-year-old woman.

H2AX phosphorylation level in peripheral blood mononuclear cells as an event-free survival predictor for bladder cancer

Bladder cancer (BC) has a typical aetiology characterized by a multistep carcinogenesis due to environmental exposures, genetic susceptibility, and their interaction. Several lines of evidence suggest that DNA repair plays a role in the development and progression of BC. In particular, the study of individual susceptibility to DNA double strand breaks (DSBs) may provide valuable information on BC risk, and help to identify those patients at high‐risk of either recurrence or progression of the disease, possibly personalizing both surveillance and treatment. Among the different DSB markers, the most well characterized is phosphorylation of the histone H2AX (γ‐H2AX). We assessed any potential role of γ‐H2AX as a molecular biomarker in a case‐control study (146 cases and 146 controls) to identify individuals with increased BC risk and at high‐risk of disease recurrence or progression. We investigated γ‐H2AX levels in peripheral blood mononuclear cells before and after their exposure to ionizing radiation (IR). We did not find any significant difference among cases and controls. However, we observed a significant association between γ‐H2AX basal levels and risk of disease recurrence or progression. In particular, both BC patients as a whole and the subgroup of non‐muscle invasive BC (NMIBC) with high basal H2AX phosphorylation levels had a decreased risk of recurrence or progression (for all BC HR 0.70, 95%CI 0.52–0.94, P = 0.02; for NMIBC HR 0.68, 95%CI 0.50–0.92, P = 0.01), suggesting a protective effect of basal DSB signaling. Our data suggest that γ‐H2AX can be considered as a potential molecular biomarker to identify patients with a higher risk of BC recurrence.

Gamma camera calibrations for the Italian multicentre study for lesion dosimetry in 223Ra therapy of bone metastases

PURPOSE The aim was to calibrate gamma cameras in the framework of the Italian multicentre study for lesion dosimetry in 223Ra therapy of bone metastases. Equipments of several manufacturers and different models were used. METHODS Eleven gamma cameras (3/8- and 5/8-inch crystal) were used, acquiring planar static images with double-peak (82 and 154keV, 20% wide) and MEGP collimator. The sensitivity was measured in air, varying source-detector distance and source size. Transmission curves were measured, calculating the parameters used for attenuation/scatter correction with the pseudo-extrapolation number method, and assessing their variations with the source size. RESULTS Values of the calibration factor (geometric mean of both detector sensitivities) ranged from 41.1 to 113.9cps/MBq. For the smallest source (diameter of 3.5cm), the calibration factor decrease ranged from -30% to -4%, highlighting the importance of partial volume effects according to the equipment involved. The sensitivity variation with the source-detector distance, with respect to the 15cm-value, reached 10% (in absolute value) in the range 5-30cm, but fixing the distance between the two heads, the calibration factor variation with the distance from the midline was within 3.6%. Appreciable variation of the transmission curves with the source size were observed, examining the results obtained with six gamma cameras. CONCLUSION Assessments of sensitivity and transmission curve variations with source size should be regularly implemented in calibration procedures. The results of this study represent a useful compendium to check the obtained calibrations for dosimetric purposes.

Letter to the editor concerning Tsuchiya K et al. "Dosimetric comparison between intensity-modulated radiotherapy and standard wedged tangential technique for whole-breast radiotherapy in Asian women with relatively small breast volumes".

With great interest, we read the recent article by Tsuchiya et al. [1]. In this paper, the authors tried to identify, in the adjuvant setting after breast-conserving surgery, the optimal radiation technique for selected 25 small breast glands (median volume, 552.6 cc), comparing the dose distribution obtained with the standard wedge tangential technique (SWT), tangential-field intensity-modulated radiation therapy (T-IMRT), and 3–4 field IMRT techniques (3FIMRT or 4F-IMRT). An improved dose distribution, a shorter treatment time, and a reduction of Radiation Therapy Oncology Group (RTOG) acute high-grade skin toxicity with the T-IMRT technique [2, 3], which can be considered a simplified form of IMRT based on two tangential fields with sub-segments, have been demonstrated [4]. In their paper, Tsuchiya et al. stated that T-IMRT can be appropriate in particular for irradiation of small breasts, because of an improvement in dose homogeneity and in the dose received by 2 % of the volume (Dmax), reducing the bilateral lung mean dose and the V20 ipsilateral lung volume, compared with the other reported techniques [1]. In our unpublished data on 30 selected patients, we have pointed out that T-IMRT leads to reducing the cutaneous acute high-grade toxicity according to the RTOG scale even if the volume of our Italian breast cancer patients was higher than the Asian one (mean 910 cc, median 775 cc). In our clinical records, the tangential technique with 6 MV photons, comparing the standard wedge tangential technique (SWT) versus T-IMRT, was used, and several dosimetric parameters for planning target volume (PTV) and organs at risks (OARs) were analyzed [3]. The collapsed cone (CC) dose calculation algorithm was applied instead of the pencil beam classic (PBC) calculation model, and a statistical analysis was performed with Student t test (p \ 0.05). T-IMRT was superior to the SWT in reducing the percentage of the PTV receiving more than 110 % (V110 %) and 107 % (V107 %) prescribed dose as well as Dmax. The reduction of V110 %, V107 %, and Dmax was 50, 30, and 3 %, respectively, without compromising PTV coverage (no significant reduction of V95 % and D98) [5]. Comparing T-IMRT with SWT, our data showed no significant dosimetric differences for the heart (Dmean, V10, V20, V30 and V50) and lung (Dmax, Dmean, V10, V20, V30 and V50) but a significant reduction of hot spots, calculated as Dmax and V50. A significantly lower dose with T-IMRT (5 % reduction for Dmean) was recorded for the controlateral breast. Furthermore, a comparison between the ipsilateral lung dose distributions obtained with CC versus PBC, for T-IMRT only, showed that the use of PBC undervalues M. G. Ruo Redda (&) S. M. Anglesio S. Allis R. Verna A. Girardi E. Trevisiol A. Reali Department of Oncology, Radiation Oncology, University of Turin, S. Luigi Gonzaga Hospital, Regione Gonzole 10, Orbassano, 10043 Turin, Italy e-mail: mariagrazia.ruoredda@unito.it

Implementation of a program for quality assurance on leaf positioning accuracy using Gafchromic ® RTQA2 films

In radiotherapy treatments the correct dose delivery to the target volume and the consequent conservation of healthy tissues is affected by multileaf collimator (MLC) leaf positioning accuracy and reproducibility, mostly in intensity-modulated radiation therapy (IMRT): For this reason a quality assurance (QA) program is necessary to ensure the best treatment possible to each patient. The aim of this study is the implementation of a method using Gafchromic® RTQA 2 films to perform routine QA on the MLC, both for qualitative and quantitative analysis. A flatbed document scanner (Epson 10000XL) was used in conjunction with radiochromic detector; a scanning protocol was firstly defined to improve readout accuracy. RTQA2 films were irradiated with 6 MV X-rays at different dose levels to obtain calibration curve. To evaluate the leaf positioning accuracy in different conditions, a rhomboidal shape and a field consisting in three rectangular segments were selected. The images quantitative analysis was handled with a program developed in MATLAB to evaluate the differences between expected and measured leaves positions. The reproducibility and global uncertainty of the method were estimated to be equal to 0.5% and 0.6 mm, respectively. Moreover, a qualitative test was performed: A garden picket fence field, consisting in multiple segments 2 × 22 cm2, was realized setting known leaves shifts to test the method sensitivity. The picket fence test shows that the method is able to detect displacements equal to 1 mm. The results suggest that Gafchromic® RTQA2 films represent a reliable tool to perform MLC routine QA.

Complete recovery from paraparesis in spinal cord compression due to extramedullary haemopoiesis in beta‐thalassaemia by emergency radiation therapy

Extramedullary haemopoiesis (EMH) is a complication commonly associated with beta‐thalassaemia intermedia; it is frequently asymptomatic but can sometimes lead to symptomatic tumour‐like masses. No guidelines or common consensus are available in literature regarding the different treatment strategies and only single cases have been reported. We describe a case of spinal cord compression due to intrathoracic EMH masses treated with combined radiotherapy and hydroxyurea.

A case report of narrowing primary tracheal mucosa-associated lymphoid tissue lymphoma: A multidisciplinary approach

Extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT) are low-grade B-cell neoplasms, which arise in mucosal sites with prolonged lymphoid proliferation. Primary tracheal MALT lymphoma is an exceedingly rare entity for which the optimal treatment approach has not been determined. Here, we report a case of MALT lymphoma involving the trachea in a 64-year-old smoking woman who received desobstructive endoscopy and was thereafter successfully treated with (anti-CD20) immunotherapy and radiotherapy.