First application of hemi-body electron beam irradiation for Kaposi sarcoma at the lower extremities.

Kaposi's sarcoma (KS) is a systemic neoplastic disease that can present cutaneous symptoms and is usually treated with a systematic approach due to its extent. Due to its radiosensitivity, radiotherapy is considered one of its main treatments, for palliation and local control of the skin and mucosal lesions. The aim of this paper was to report the first case of KS treated by hemi-body electron irradiation protocol in Greece. A fractionated 40 Gy hemi-body electron irradiation was prescribed to a 60-year-old male patient with KS at his legs. Dose uniformity was verified on a daily basis by thermoluminescence dosimetry (TLD). The treatment resulted to complete clinical response. Limited irradiation-derived side effects appeared. This is the first case ever to be treated with hemi-body electron irradiation protocol in Greece. To the best of our knowledge, this is also the first time that a single field hemi-body electron beam irradiation at a total skin electron beam (TSEB)-like configuration is reported to be used for KS.

Determination of beam profile characteristics in radiation therapy using different dosimetric set ups.

PURPOSE: The purpose of this study was to analyze and to compare results regarding the penumbra size, flatness and symmetry obtained using six different measuring systems. METHODS: Beam profile measurements were performed in standard water phantom set-up for two photon beams for various square field sizes and for five electron beams for several applicator sizes at several depths. Six measuring systems were used: three ionization chambers; a Semiflex (31002, PTW), a Markus (23343, PTW) and a Roos (34001, PTW); Two semiconductor detectors; a p-type diode (60008, PTW) and an e-type diode (60017, PTW) and a one dimensional Linear Array (LA48, PTW). RESULTS: Our results indicate that penumbra size determination is strongly dependent on the measuring system. For the photon measurements the diodes showed the narrowest penumbra followed by the LA48, while the largest penumbra was presented by the Semiflex. The unshielded diode overestimates the penumbra in large field sizes and big depths. The parallel plate ionization chambers overestimate the penumbra width of electron beam profiles. The LA48 presents the most symmetric beam profiles. CONCLUSIONS: Regarding penumbra size determination, the LA48 can be considered acceptable in terms of accuracy, and is the most time-effective system. It is also adequate for symmetry and flatness measurements. For greatest possible accuracy silicon diode is recommended. Parallel plate ionization chambers are not appropriate for penumbra measurements.

A five split-field three dimensional conformal technique versus an anterior-posterior on in postoperative radiotherapy for gastric carcinoma: a multicenter comparative study using quality of life measurements as well as clinical and dosimetric parameters.

PURPOSE: Several adjuvant approaches are regarded as available options in the management of localized, resectable gastric cancer .The objective of our study was to evaluate multiple field and anteroposterior conformal technique. METHODS: Ninety-seven patients received three dimensional conformal (3DCRT) postoperative adjuvant radiation therapy for gastric carcinoma. Thirty-five patients received anteroposterior (AP/PA) fields (Group B), while 62 patients were irradiated with multifield technique (Group A). Their ages ranged between 29-85 years. The objective of the study was to evaluate the quality of life (QoL) for all patients after the completion of radiotherapy using the QLQ-C30 of the EORTC questionnaire (European Organization for Research and Treatment of Cancer) and to investigate any measurable differences between those two radiation techniques according to QUANTEC criteria and the radiotoxicity. RESULTS: In terms of QUANTEC criteria, the multifield technique was superior concerning the left kidney (p=0.025), right kidney (p<0.001), spinal cord (p<0.001) and planning target volume (PTV) coverage (p<0.001). According to EORTC/ RTOG toxicity criteria, the rate of diarrhea was higher in AP/ PA technique (p=0.028). In terms of QLQ-C30, the multifield technique was superior concerning appetite loss (p=0.022), diarrhea (p=0.046) and global QoL (p<0.001). CONCLUSION: On the basis of QLQ-C30 questionnaire, EORTC/ RTOG toxicity and dosimetric parameters, the present report has shown that the three dimensional multifield conformal radiotherapy is superior compared to AP-PA techniques.

Toxicity and efficacy of a hypofractionated (3 weekly fractions of 850c Gy) irradiation schedule for stage IIIb / IV non-small cell lung cancer elderly patients with low performance status and unfit for chemotherapy.

PURPOSE: To evaluate in an observational way the clinical impact of a hypofractionated irradiation schedule in patients with unresectable non-small cell lung cancer (NSCLC). METHODS: Forty elderly patients (24 men/16 women) diagnosed with unresectable stage IIIb/IV NSCLC unfit for chemotherapy, were treated with once-a-week hypofractionation schedule. All patients had a poor performance status. A dose of 255 Gy in 3 weekly fractions was prescribed while a 3D conformal technique (3D-CRT) was used for irradiation. The primary study endpoints were to assess the therapeutic impact of this schedule in terms of relapse free survival (RFS), overall survival (OS) survival and palliation of symptoms. The secondary endpoints were the evaluation of acute toxicity of the lung, esophagus and the skin. The intended followup was 3 years. The median age was 73.5 years (range 71-85). RESULTS: The median RFS was 12 months, while the median OS was 17 months. Symptoms relief was up to 20% for cough, 52.5% for haemoptysis, 40% for thoracic pain and 17.5% for dyspnoea. Acute lung toxicity in terms of radiation pneumonitis was recorded as 6/40 (15%) grade 1, 26/40 (65%) grade 2 and 8/40 (25%) grade 3. Additionally, grade 1 and 2 acute esophageal toxicity was recorded in 10/40 (25%) and 30/40 (75%) patients, respectively. Acute skin toxicity with grade 2 erythema was recorded in only 2/40 (5%) patients while most patients developed grade 1 skin erythema. Grade 3 late lung toxicity was recorded in 10/40 (25%) patients. CONCLUSIONS: This study showed that the proposed scheme has a moderate radiation-induced lung toxicity rate and an acceptable therapeutic ratio. Taking into consideration its cost effectiveness, the proposed hypofractionated scheme is a good alternative to conventional fractionation.

Review of the three-field techniques in breast cancer radiotherapy.

Breast cancer is often treated with radiotherapy (RT), with two opposing tangential fields. When indicated, supraclavicular lymph nodes have to be irradiated, and a third anterior field is applied. The junction region has the potential to be over or underdosed. To overcome this problem, many techniques have been proposed. A literature review of 3 Dimensional Conformal RT (3D CRT) and older 3-field techniques was carried out. Intensity Modulated RT (IMRT) techniques are also briefly discussed. Techniques are categorized, few characteristic examples are presented and a comparison is attempted. Three-field techniques can be divided in monoisocentric and two-isocentric. Two-isocentric techniques can be further divided in full field and half field techniques. Monoisocentric techniques show certain great advantages over two-isocentric techniques. However, they are not always applicable and they require extra caution as they are characterized by high dose gradient in the junction region. IMRT has been proved to give better dosimetric results. Three-field matching is a complicated procedure, with potential of over or undredosage in the junction region. Many techniques have been proposed, each with advantages and disadvantages. Among them, monoisocentric techniques, when carefully applied, are the ideal choice, provided IMRT facility is not available. Otherwise, a two-isocentric half beam technique is recommended.

In vivo dosimetry in the field junction area for 3D-conformal radiation therapy in breast and head & neck cancer cases: A quality assurance study.

PURPOSE: To investigate the accuracy of field junctioning planning techniques (monoisocentric and rotating couch technique) for 3D-conformal radiotherapy (3D-CRT). METHODS: In vivo dosimetry has been performed using thermo- luminescence dosimeters (TLDs) in 10 head and neck cancer patients (treated with monoisocentric technique) and 10 breast cancer patients (treated with rotating couch technique) irradiated with a 6 MV photon beam. Entrance dose measurements were performed in selected regions including the field junction area. RESULTS: The mean deviation between measured and expected dose in the region of junction was significantly higher in breast cases compared to head and neck irradiation (-2.8±15.4% and 0.2±8.2% respectively; Mann-Whitney U test: p=0.002). A comparison between lateral head and neck fields and tangential breast fields revealed that the latter was associated with larger dose discrepancies (-2.2 ± 4.6% vs -3.5 ± 5.7% respectively; Mann-Whitney U test: p=0.029). CONCLUSIONS: The results indicate the superiority of monoisocentric technique compared to the rotating couch technique in terms of dose delivery accuracy for treatments with field junctioning planning techniques.

A hypofractionated radiotherapy schedule with 57.75Gy in 21 fractions for T1-2N0 prostate carcinoma: Analysis of late toxicity and efficacy.

PURPOSE: The primary endpoint was to assess the late toxicity of a hypofractionated radiotherapy schedule in relation to radiation parameters concerning the rectum and bladder. The second endpoint was to assess a composite of biochemical and clinical failure. METHODS: Sixty-four prospectively selected patients diagnosed with localized low risk prostate cancer, Gleason score (GS) <7, PSA <10, and T1-2N0, were treated with external 3- dimensional conformal radiotherapy (3D-CRT). Patients received 57.75 Gy in 21 daily fractions of 2.75 Gy/fraction. RESULTS: Late gastrointestinal (GI) toxicity was as follows: grade 0: 47 (73.4 %) patients, grade 1: 12 (19.2 %), grade 2: 4 (6.3%), and grade 3: 1 (1.6%). There was a significant correlation between D50, V70 and EORTC/RTOG late rectal toxicity score (p<0.001 and p=0.006, respectively). Grade 1 and 2 late bladder toxicity was seen in 4.7 and 1.6% of the patients, respectively. With a median follow up of 18 months no biochemical relapse was observed. CONCLUSION: The present study supports the use of hypofractionated radiation therapy which showed a high therapeutic ratio with acceptable toxicity and no biochemical relapse during follow-up.

First treatment of mycosis fungoides by total skin electron beam (TSEB) therapy in Greece.

BACKGROUND: Mycosis fungoides (MF), the most common subtype of cutaneous T-Cell Lymphoma (CTCL), is a rare chronic skin neoplasia. Total skin electron irradiation has been employed along with a variety of other topical or systemic treatments for MF management. AIM: To report the first case treated by TSEB irradiation protocol in Greece. MATERIALS AND METHODS: A fractionated 36 Gy total skin electron beam (TSEB) therapy was prescribed to a 65-years-old male patient with mycosis fungoides (MF), stage IIB, refractory to several treatments during a 20-year period. Dose uniform delivery was monitored by thermo-luminescence dosimetry. RESULTS AND DISCUSSION: The homogeneous skin dose distribution resulted in a complete clinical response. Limited, irradiation-oriented, side effects appeared. CONCLUSIONS: The first TSEB irradiation prescription in Greek medical chronicles was proved effective in this case of tumor stage MF (T3-IIB), which had been refractory to several single or combination treatments.

Probing the Effects of Ionizing Radiation on Young's Modulus of Human Erythrocytes Cytoskeleton using Atomic Force Microscopy.

PURPOSE/AIM: In this work, we examined the possible effects of ionizing radiation (IR) on biomechanical properties of the membrane-cytoskeleton of human erythrocytes, after X-ray irradiation. MATERIALS AND METHODS: Whole human blood from three healthy middle-aged volunteers was drawn by venipuncture and stored in tubes containing anticoagulant. Six blood samples were collected for each volunteer. Five of them were irradiated in the range of 0.1 Gy-2.0 Gy doses and one was used as control. The morphology and the elastic modulus of the erythrocytes were examined using atomic force microscopy and just few drops of whole blood. RESULTS: No morphological changes appeared according to the shape and the morphology of the erythrocytes. The elastic modulus of the irradiated samples was reduced with the increase of radiation dose. The findings indicate that X-ray irradiation affects the biomechanical properties of erythrocyte cytoskeleton. The mean value of Young's modulus of all the irradiated blood samples was significant difference from the control at a level, P < 0.01. CONCLUSIONS: The elastic modulus of the erythrocytes could be an indicator of the adverse effect in the human blood generated by IR exposure through a radiotherapy treatment.

Clinical application of Total Skin Electron Beam (TSEB) therapy for the management of T cell cutaneous lymphomas. The evolving role of low dose (12 Gy) treatment schedule.

BACKGROUND & PURPOSE: Although rare, cutaneous lymphomas represent a separate entity in hematologic oncology. T cell origin lymphomas are most common, with Mycosis Fungoides (MF) accounting for about 50-70% of cases. Sezary Syndrome (SS), which represents the leukemic varian of MF, accounts for 3% of Cutaneous T Cell Lymphomas (CTCL). Total Skin Electron Beam Therapy (TSEB) is included at the mainstream of treatment choices for CTCL. The scope of this study is to evaluate the effectiveness and toxicity of two treatment schedules of TSEB. METHODS AND MATERIALS: We report our experience with TSEB in the management of MF and SS, as of 14 patients treated in our institution from 2011 to 2015. 8 patients received the 12 Gy (low dose) scheme while 6 patients were managed with 36 Gy (standard or full dose scheme) according to six dual field Stanford technique. The endpoints were overall response rate, duration of response and toxicity of treatment. RESULTS: After a median follow up of 2.5 years we noted excellent treatment outcome, with both schemes being well tolerated and resulting in comparable response rates. The overall response rate for both treatment regimens was over 87.5%. Treatment was well tolerated with mild toxicity. CONCLUSION: The role of TSEB in the management of MF and SS is well established. The low dose TSEB schedule of 12 Gy is an effective treatment option, since therapeutic results are more than acceptable, compliance is excellent and toxicity is minimal. Moreover, the evidence that it can be repeated safely makes it more attractive than the standard 36 Gy scheme, when a patient is referred to radiation treatment according to treatment guidelines.

Participation of women medical Physicists in European scientific events: The European experience.

PURPOSE: Though the number of women scientists is increasing over the years, studies show that they are still under-represented in leadership roles. The purpose of this work is to establish the percentage of women Medical Physicists (wMPs) that have participated in European scientific events and evaluate it as an indication of the current position of women in the field of Medical Physics in Europe and to propose possible ways to encourage their participation. MATERIALS AND METHODS: Data regarding the participants in European scientific events of Medical Physics were collected. The participants were divided into categories according to the program of the events and their gender was identified. The percentage of wMPs in each category was evaluated. RESULTS: The participation of wMPs attending courses is greater than 50%. The categories with the greatest participation are "Organizing Committees", "Chairpersons-Moderators" and "Oral Presentations". The categories with the lower participation of wMPs are "Scientific Committee", "Symposiums" and "Invited Speakers". None of wMPs were represented as "Course Directors". CONCLUSIONS: The attendance of wMPs in courses is slightly greater than average. However, wMPs do not have an equally important recognition in special invited roles in conferences. They are still under-represented in "Scientific Committees", "Invited Speakers", "Symposiums" and "Course directors". wMPs should be encouraged to participate even more actively in European conferences and the organizing committees should invite more wMPs in special roles. More studies concerning the status of female MPs in each country separately should be encouraged as they will help in understanding the position of wMPS in Europe.

A novel Hemi-Body Irradiation technique using electron beams (HBIe-).

PURPOSE: Certain radiation responsive skin diseases may develop symptoms on the upper or the lower half of the body. The concept of a novel Hemi-Body Electron Irradiation (HBIe-) technique, described in this work, provides a low cost, LINAC based, intermediate treatment option in between extremely localized and Total Skin irradiation techniques. MATERIALS AND METHODS: The HBIe- technique, developed in our department, incorporates a custom crafted treatment chamber equipped with adjustable Pb shielding and a single electron beam in extended Source-Skin Distance (SSD) setup. The patient is positioned in 'Stanford' technique positions. The geometrical setup provides both optimal dose homogeneity and dose deposition up to a depth of 2 cm. To confirm this, the following characteristics were measured and evaluated: a) percentage depth dose (PDD) on the treatment plane produced by a single electron beam at perpendicular incidence for six fields at 'Stanford' angles, b) 2D profile of the entrance dose on the treatment plane produced by a single field and c) the total surface dose on an anthropomorphic phantom delivered by all 6 fields. RESULTS: The resulting homogeneity of the surface dose in the treatment plane for an average patient was 5-6%, while surface dose homogeneity on the anthropomorphic phantom was 7% for both the upper and the lower HBIe- variants. The total PDD exhibits an almost linear decrease to a practical range of 2 g/cm2. CONCLUSION: In conclusion, HBIe- was proven effective in delivering the prescribed dose to the target area, while protecting the healthy skin.

Theoretical and experimental determination of scaling factors in electron dosimetry for 3D-printed polylactic acid.

PURPOSE: Plastic phantoms are commonly used in daily routine for dosimetric tasks in radiation therapy. Although water is the reference medium according to the dosimetric protocols, measurements with nonwater phantoms are easier to be performed. To succeed absorbed dose determination, certain scaling factors have to be applied to the acquired measurements. Taking into account the increased availability of three-dimensional (3D) printing, we attempted to obtain scaling factors for polylactic acid (PLA), a commonly used thermoplastic material for 3D printing. METHODS: Measurements were performed with a custom-made phantom from PLA material, which was designed and constructed using 3D printing technology. Depth and fluence scaling factors were obtained within the range of 6 to 20 MeV. Moreover, Monte Carlo simulations were performed to verify the measured results. RESULTS: Experimental and Monte Carlo (MC) values showed a good agreement, especially in lower energies. Mean value of depth scaling factor (cpl ) over the whole range of energies was 0.946, while mean fluence scaling factor (hpl ) was found to be 1.050. For energies below 10 MeV, the corresponding mean values for cpl and hpl were 0.946 and 1.054, respectively. CONCLUSIONS: PLA phantoms could be constructed and used for electron beam nonreference measurements, reproducing even more complex geometries, from simple quality assurance devices to geometrically complicated anthropomorphic phantoms.

A Retrospective Analysis of Toxicity and Efficacy for 2 Hypofractionated Irradiation Schedules Versus a Conventional One for Post-Mastectomy Adjuvant Radiotherapy in Breast Cancer.

INTRODUCTION: The aim of this analysis was a retrospective evaluation of the efficacy and toxicity of 2 hypofractionated irradiation schedules compared to conventional therapy in post-mastectomy patients. METHODS: 3 irradiation schedules were analyzed: 48.30 Gy in 21 fractions (group A, n = 60), 42.56 Gy in 16 fractions (group B, n = 27) and 50 Gy in 25 fractions (group C, n = 30) of the front chest wall. All groups were also treated with a supraclavicular field, with 39.10 Gy in 17 fractions (group A), 37.24 Gy in 14 fractions (group B) or 45 Gy in 25 fractions (group C). RESULTS: No local recurrences were noted in any group during 36 months of follow-up. Acute skin toxicity presented in all groups, with 58.3%, 70.4% and 60% of grade I; 35%, 25.9% and 40% of grade II; 6.7%, 3.7% and 0% of grade III being seen in groups A, B and C, respectively. Late skin toxicity was noted only as grade I in 16.7%, 25.9% and 26.7% of groups A, B and C, respectively. No significant difference was noted among all groups for either acute or late skin toxicity, or for radio-pneumonitis (chi2 test, p > 0.05). CONCLUSION: All schedules were equally effective with equivalent toxicity. A prospective randomized study is needed to confirm our results.

Adjuvant chemotherapy and acute toxicity in hypofractionated radiotherapy for early breast cancer.

AIM: To evaluate the effect of chemotherapy to the acute toxicity of a hypofractionated radiotherapy (HFRT) schedule for breast cancer. METHODS: We retrospectively analyzed 116 breast cancer patients with T1, 2N0Mx. The patients received 3-D conformal radiotherapy with a total physical dose of 50.54 Gy or 53.2 Gy in 19 or 20 fractions according to stage, over 23-24 d. The last three to four fractions were delivered as a sequential tumor boost. All patients were monitored for acute skin toxicity according to the European Organization for Research and Treatment of Cancer/Radiation Therapy Oncology Group criteria. The maximum monitored value was taken as the final grading score. Multivariate analysis was performed for the contribution of age, chemotherapy and 19 vs 20 fractions to the radiation acute skin toxicity. RESULTS: The acute radiation induced skin toxicity was as following: grade I 27.6%, grade II 7.8% and grade III 2.6%. No significant correlation was noted between toxicity grading and chemotherapy (P = 0.154, χ(2) test). The mean values of acute toxicity score in terms of chemotherapy or not, were 0.64 and 0.46 respectively (P = 0.109, Mann Whitney test). No significant correlation was also noted between acute skin toxicity and radiotherapy fractions (P = 0.47, χ(2) test). According to univariate analysis, only chemotherapy contributed significantly to the development of acute skin toxicity but with a critical value of P = 0.05. However, in multivariate analysis, chemotherapy lost its statistical significance. None of the patients during the 2-years of follow-up presented any locoregional relapse. CONCLUSION: There is no clear evidence that chemotherapy has an impact to acute skin toxicity after an HFRT schedule. A randomized trial is needed for definite conclusions.

Transformation of physical DVHs to radiobiologically equivalent ones in hypofractionated radiotherapy analyzing dosimetric and clinical parameters: a practical approach for routine clinical practice in radiation oncology.

PURPOSE: The purpose of this study was to transform DVHs from physical to radiobiological ones as well as to evaluate their reliability by correlations of dosimetric and clinical parameters for 50 patients with prostate cancer and 50 patients with breast cancer, who were submitted to Hypofractionated Radiotherapy. METHODS AND MATERIALS: To achieve this transformation, we used both the linear-quadratic model (LQ model) and the Niemierko model. The outcome of radiobiological DVHs was correlated with acute toxicity score according to EORTC/RTOG criteria. RESULTS: Concerning the prostate radiotherapy, there was a significant correlation between RTOG acute rectal toxicity and D50 (P < 0.001) and V60 (P = 0.001) dosimetric parameters, calculated for α/ß = 10 Gy. Moreover, concerning the breast radiotherapy there was a significant correlation between RTOG skin toxicity and V(≥60) dosimetric parameter, calculated for both α/ß = 2.3 Gy (P < 0.001) and α/ß = 10 Gy (P < 0.001). The new tool seems reliable and user-friendly. CONCLUSIONS: Our proposed model seems user-friendly. Its reliability in terms of agreement with the presented acute radiation induced toxicity was satisfactory. However, more patients are needed to extract safe conclusions.

Assessment of contralateral mammary gland dose in the treatment of breast cancer using accelerated hypofractionated radiotherapy.

AIM: To measure the dose distribution, related to the treatment planning calculations, in the contralateral mammary gland of breast cancer patients treated with accelerated hypofractionated 3-dimensional conformal radiotherapy. METHODS: Thirty-four prospectively selected female patients with right breast cancer (pN0, negative surgical margins) were treated with breast-conserving surgery. A total dose of 42.5 Gy (2.66 Gy/fraction) was prescribed; it was requested that planning target volumes be covered by the 95% isodose line. The contralateral mammary gland was defined on CT simulation. The dose received was evaluated by dose volume histograms. RESULTS: The measured contralateral breast doses were: (1) Dose maximum: 290-448 cGy [Equivalent (Eq) 337-522 cGy]; (2) Mean dose: 45-70 cGy (Eq 524-815 cGy); and (3) Median dose: 29-47 cGy (337-547 cGy) for total primary breast dose of 42.5 Gy in 16 equal fractions. The spearman rho correlation showed statistical significance between the contralateral breast volume and maximum dose (P = 0.0292), as well as mean dose (P = 0.0025) and median dose (P = 0.046) to the breast. CONCLUSION: Minimizing the dose to the contralateral breast has to be one of the priorities of the radiation oncologist when using short schedules because of the radiosensitivity of this organ at risk. Further study is necessary to assess the long-term clinical impact of this schedule.