ResultsSeventy-five patients (93.7%) had nodal involvement that was bilateral in 69 patients (86,2%).The high risk levels were II (>85%) and III (>50%) (table 1).The low risk levels were Ia (0%) and VIIb (<3%).Level Right (%) Left (%) Ia 0 0 Ib 13 (16.3)18 (22.5)II 71 (88.8) 74 (92.5)III 42 (52.5)50 (62.5)IV 19 (23.8) 29 (36.3)Va-b 17 (21.3)18 (22.5)Vc 10 (12.5) 18 (22.5)

Purpose Stereotactic Body Radiation Therapy (SBRT) for patients with early stage solid tumor is increasing thanks to modern technologies and integrated image-guided systems. A national study to evaluate the influence of calculation grid resolution and CT slice thickness on small fields calculated in an homogeneous phantom, is in progress. For this purpose, a preliminary investigation that collected different parameters on TPS management at Italian level, was performed. Methods Twenty-eight centres of the Italian Association of Medical Physics (AIFM) SBRT working group were invited to fill out a questionnaire expressly prepared by expert Medical Physicists using Google Forms. Questions regarded: type of accelerator, MLC characteristics, CT images scan information, Treatment Planning System (TPS) type, strategy used for SBRT plans, small fields OF values, detector/detectors and set-up adopted for measurements. Results Preliminary results from 28 centers show great heterogeneities. Most centers used LINACs with MLC width ⩽5 mm, 6MV and VMAT technique. 60% of centers used more than one detector to measure OFs and no corrective factor was adopted in small field data. 10 × 10 cm2 field size was the normalization field. OF data inserted in TPS did not come from a multicenter OF measurements. 1 × 1 cm2 was the smallest field size measured for 47% of centers. As for TPS, PB, CCC, MC, AAA and deteministic algorithms were used in 3%, 40%, 23%, 27% and 7% of centers, respectively. About 29% and 21 % of centers used 3 mm and 2 mm as CT slice thickness, respectively. 50% of centers used 2 mm calculation grid. Conclusions The influence of the dose calculation resolution and CT slice thickness on small OFs has not been studied yet. This preliminary study, considered as the starting point, highlighted a great spread of answers of the participating center and could be used as a baseline for future investigations.

ESTRO 36 _______________________________________________________________________________________________ acute GI toxicity grade I was observed in 6 patients (17.1%) and grade II in 3 patients (8.6%).No late grade III-IV GU or GI toxicity was detected.For one patient a TURP was planned at 8 months after treatment, for urethral stricture.Only 1 patient (3%) developed biochemical recurrence after a follow-up of 27 months. ConclusionHypo-RT (63,4 Gy/20 fractions) with a high equivalent BED (EQD2Gy_tumor = 85 Gy) produces aceptable acute and sub-acute toxicity rates with excellent outcomes of biochemical control for intermediate risk prostate cancer.Longer term follow-up should be analyzed to confirm these data.

Introduction: In-vivo dosimetry should be the ultimate step of a treatment planning verification programme allowing to check the whole dosimetry procedure including occurrence of possible human errors. However, to benefit from in-vivo dosimetry detectors that combine good accuracy, precision and ease of use are required. To meet this demand a new diamond detector in a wireless configuration has been developed and tested.

Introduction: In prostate cancer radiotherapy, the relationship between genitourinary (GU) toxicity and clinical and dosimetric parameters is debated. The aim of this study is to analyze the associations among GU toxicity and dosimetric and clinical parameters in patients treated with 3D conformal radiotherapy for localized prostate cancer.

Conclusion:Treatment intensification in NSCLC via targeted dose escalation with modern delivery techniques offers the potential for a significant increase in tumour control probability without a clinically significant increase in predicted OAR toxicity.

Introduction: The aim of the present study was to compare volumetric modulated arc therapy (VMAT), intensity-modulated radiotherapy (IMRT) and 3D-conformal radiotherapy (3DCRT) in their ability to spare organs at risk (OARs) and to cover planning target volume (PTV) in upper abdominal cancer treatments.

PURPOSE Aim of the present work is to evaluate the synthetic single crystal diamond Schottky photodiode developed at the laboratories of "Tor Vergata" University in Rome in a new dosimeter configuration specifically designed for offline wireless in vivo dosimetry (IVD) applications. METHODS The new diamond based dosimeter, single crystal diamond detector (SCDD-iv), consists of a small unwired detector and a small external reading unit that can be connected to commercial electrometers for getting the detector readout after irradiation. Two nominally identical SCDD-iv dosimeter prototypes were fabricated and tested. A basic dosimetric characterization of detector performances relevant for IVD application was performed under irradiation with (60)Co and 6 MV photon beams. Preirradiation procedure, response stability, short and long term reproducibility, leakage charge, fading effect, linearity with dose, dose rate dependence, temperature dependence, and angular response were investigated. RESULTS The SCDD-iv is simple, with no cables linked to the patient and the readout is immediate. The range of response with dose has been tested from 1 up to 12 Gy; the reading is independent of the accumulated dose and dose rate independent in the range between about 0.5 and 5 Gy/min; its temperature dependence is within 0.5% between 25 and 38 °C, and its directional dependence is within 2% from 0° to 90°. The combined relative standard uncertainty of absorbed dose to water measurements is estimated lower than the tolerance and action level of 5%. CONCLUSIONS The reported results indicate the proposed novel offline dosimeter based on a synthetic single crystal diamond Schottky photodiode as a promising candidate for in vivo dosimetry applications with photon beams.

High-energy electron beams generated by linear accelerators, typically in the range 6 to 20 MeV, are used in small field sizes for radiotherapy of localized superficial tumors. Unshielded silicon diodes (Si-D) are commonly considered suitable detectors for relative dose measurements in small electron fields due to their high spatial resolution. Recently, a novel synthetic single crystal diamond diode (SCDD) showed suitable properties for standard electron beams and small photon beams dosimetry. The aim of the present study is twofold: to characterize 6 to 15 MeV small electron beams shaped by using commercial tubular applicators with 2, 3, 4 and 5 cm diameter and to assess the dosimetric performance under such irradiation conditions of the novel SCDD dosimeter by comparison with commercially available dosimeters, namely a Si-D and a plane–parallel ionization chamber. Percentage depth dose curves, beam profiles and output factors (OFs) were measured. A good agreement among the dosimeters was observed in all of the performed measurements. As for the tubular applicators, two main effects were evidenced: (i) OFs larger than unity were measured for a number of field sizes and energies, with values up to about 1.3, that is an output 30% greater than that obtained at the 10 × 10 cm2 reference field; (ii) for each diameter of the tubular applicator a noticeable increase of the OF values was observed with increasing beam energy, up to about 100% in the case of the smaller applicator. This OF behavior is remarkably different from what typically observed for small blocked fields having the same size and energy as those used in this study. OFs for tubular applicators depend considerably on the field size, so interpolation is unadvisable to predict the linear accelerator output for such applicators whereas reliable high-resolution detectors, as the silicon and diamond diodes used in this work allow OF measurements with uncertainties of about 1%.

AIM:Fatigue can be defined as an unpleasant feeling of tiredness, weakness and lack of energy. It is found in about 80% of the patients receiving radiation therapy and has a significant impact on quality of life. The aim of this paper was to assess the frequency, severity and changes of fatigue before, during and after administration of a nutraceutical (mixture of whey protein with an high biological value, with an high content in native cysteine, albumin and lactoferrin in patients undergoing treatment for breast and prostate cancer.METHODS:Thirty patients (20 breast and 10 prostate ones) were enrolled in our test and they received a questionnaire about Fatigue developed by the University of Texas, MD Anderson Cancer Center, 1999. The patients who achieved a score between 4 and 6 were administered the nutraceutical (Prother) at a dose of 20 g / day for the first 10 days of radiation treatment and then 10 g/day for the following 20 days without considering the terms of the radiation oncology treatment [corrected]. Each patient was reassessed using the same Fatigue test after 10 and 30 days from the start of the administration of nutraceutical. We enrolled 30 control patients who did not receive Prother.RESULTS:The results showed the effectiveness of Prother in all patients with moderate-to-mild fatigue.CONCLUSION:The administration of Prother has therefore been effective in terms of both improving the compliance of the radiation treatment and the quality of life.

2nd ESTRO Forum 2013 S475 of 1.4 cm vertically, 1.6 cm longitudinally and 1 cm laterally in prostate cancer patients and 0.5 cm vertically or longitudinally and 0.7 cm laterally in H&N patients.In prostate cancer patients the 98% of the MTS were less then 1 cm, while in H&N patients the MTS was less than 0.5 cm in 92% of the cases.Therefore the mean (±SD) 3D vector of displacement was 0.3±0.7 cm and 0,2±0,4 cm for the prostate and H&N group respectively.The magnitude of roll variation was greater in both groups (mean (±SD) of -0.5±1.2° in prostate and a maximal value of 3.8° and a mean (±SD) of 1.3±1,2 ° in H&N with a maximal value of 3.4°).The pitch variations were greater for patients treated to the pelvis (means (±SD) of -0.4±1.1°vs -0.1±0.8° with a maximal value of 2.8° vs 1.9°), while the mean (±SD) interfractional yaw was 0.1±0.7° in prostate and 0.0±0.6° in H&N patients.No correlation was observed between the magnitude of translational and rotational shift in either group.The procedure of online correction added less than one minute to the treatment time when compared to IGRT without robotic 6 DOF couch.The total treatment time (±SD) (IGRT plus delivery) was: 14.52±2.02min., 15.26±1.52min., 24.53±5.47min.for prostate RapidArc, brain RapidArc and H&N IMRT respectively.Conclusions: This data confirms the relevance of rotational shifts in prostate and H&N patients.The correlation between immobilization systems and the rotational shift value is not strong enough to refrain from implementing the robotic couch in IGRT high precision radiotherapy treatments.

PURPOSE:To investigate the dosimetric properties of synthetic single crystal diamond based Schottky diodes under irradiation with therapeutic electron beams from linear accelerators.METHODS:A single crystal diamond detector was fabricated and tested under 6, 8, 10, 12, and 15 MeV electron beams. The detector performances were evaluated using three types of commercial detectors as reference dosimeters: an Advanced Markus plane parallel ionization chamber, a Semiflex cylindrical ionization chamber, and a p-type silicon detector. Preirradiation, linearity with dose, dose rate dependence, output factors, lateral field profiles, and percentage depth dose profiles were investigated and discussed.RESULTS:During preirradiation the diamond detector signal shows a weak decrease within 0.7% with respect to the plateau value and a final signal stability of 0.1% (1σ) is observed after about 5 Gy. A good linear behavior of the detector response as a function of the delivered dose is observed with deviations below ±0.3% in the dose range from 0.02 to 10 Gy. In addition, the detector response is dose rate independent, with deviations below 0.3% in the investigated dose rate range from 0.17 to 5.45 Gy∕min. Percentage depth dose curves obtained from the diamond detector are in good agreement with the ones from the reference dosimeters. Lateral beam profile measurements show an overall good agreement among detectors, taking into account their respective geometrical features. The spatial resolution of solid state detectors is confirmed to be better than that of ionization chambers, being the one from the diamond detector comparable to that of the silicon diode. A good agreement within experimental uncertainties was also found in terms of output factor measurements between the diamond detector and reference dosimeters.CONCLUSIONS:The observed dosimetric properties indicate that the tested diamond detector is a suitable candidate for clinical electron beam dosimetry.