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Background/Objectives: The lung is the most common site of metastases, regardless of the cancer subtype. Treating oligometastatic disease with surgery or stereotactic ablative radiotherapy (SABR) may improve patient survival. Methods: We retrospectively analyzed 41 patients with limited (one or two lesions, max dimension <3 cm) lung-only metastatic disease that were treated with the CK M6 robotic radiosurgery system in our Department, in terms of treatment efficacy and toxicity. Results: Acute and late toxicity was negligible (4 out of 41 patients developed grade 2 or 3 lung fibrosis). Six months post-SABR, complete response was achieved in 18 out of 41 patients (43.9%), while the rest of the cases exhibited major responses. A biological effective dose (BEDα/β=10) in the range of 100 Gy appears to be equally effective with higher doses. Within a median follow-up of 34 months, only three patients (7.3%) progressed locally, while three patients progressed to distal sites. Two-year local progression-free survival (LPFS) rates were 92.6% (95% CI 78.5–97%). Conclusions: SABR for low-burden lung oligometastases is an effective treatment modality that yields high local control and survival rates. Toxicity is negligible, regardless of the performance status of patients. Early referral of such patients to radiation oncology departments may be critical for patient survival and quality of life. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of the study is to measure anatomical and dosimetric changes experienced by patients with head and neck cancer undergoing intensity-modulated radiation therapy and evaluate the need for adaptive radiotherapy using predefined relative thresholds as benchmarks. Methods: This study involved 31 consecutive patients. Two computed tomography (CT) scans were utilized for initial treatment planning and a midpoint assessment. The study employed rigid registration and contour transfer techniques to apply primary dose calculation to midpoint CT, generating a hybrid plan, and an adaptive plan was generated on the midpoint CT. Results: The results revealed statistically significant volume reductions mainly in PTV70, PTV60 and PTV54 volumes. The volume of the parotid glands exhibited volumetric reductions in most of the patients. Hybrid plans demonstrated inferior dose coverage of the tumour regions, and comparisons between hybrid and adaptive plans showed significant variations in the maximum doses. Conclusions: Anatomical deviations necessitating a repeat CT scan, along with the application of a new immobilization mask, emerged as a primary rationale for replanning. Indicators that could potentially encompass a breach of 95% dose coverage for 95% of the tumour volume, maximum doses surpassing 50 Gy in the spinal cord and 59 Gy in the brainstem<>, as well as lateral neck displacement exceeding 1cm from the initial position act as benchmarks before implementing a replan. [ABSTRACT FROM AUTHOR]

Simple Summary: In this article, we report the results of an interim analysis of 81 early-stage lung cancer patients undergoing stereotactic ablative radiotherapy with the CyberKnife M6 robotic radiosurgery system, with the endpoints being treatment efficacy and tolerance. Within a median follow-up of 20 months, a grade 2/3 lung toxicity of no clinical significance was reported in 6% of the patients. A higher biological effective dose and larger irradiation lung volumes were associated with increased toxicity. The projected 24-month local progression-free survival rate was 95%. These results confirm the safety and efficacy and further cement the role of robotic stereotactic ablative radiotherapy for early-stage lung cancer patients as an eventual alternative to surgery. Background/Objectives: Surgery is the primary treatment for early-stage lung cancer. Patients with medically inoperable lung carcinomas and patients who refuse to undergo surgery are treated with definite radiotherapy. Stereotactic ablative radiotherapy (SABR) is a compelling non-invasive therapeutic modality for this group of patients that confers promising results. Methods: We report an interim analysis of an ongoing trial. Eighty-one patients with medically inoperable early-stage (T1,2N0) lung cancer underwent SABR in our institution. SABR was delivered via the CyberKnife M6 robotic radiosurgery system. The endpoints of the analysis were treatment efficacy and tolerance. Results: There were no acute or late toxicities from the skin or the connective tissue of the thorax. A grade 2/3 lung injury of non-clinical significance was noted in 6% of patients, which was directly related to a higher biologically effective dose (BEDα/β = 3) and larger irradiation lung volumes in both univariate and multivariate analyses. A local control (LC) was achieved in 100% of the patients at the first follow-up, and the projected 24-month local progression-free survival (LPFS) rate was 95%. The projected 24-month disease-specific overall survival (OS) was 94%. Conclusions: High LC and OS rates can be achieved with SABR for early-stage lung cancer, with minimal toxicity. This study continues to recruit patients. [ABSTRACT FROM AUTHOR]

Concerning clinical trials, intracavitary hyperthermia has already shown antitumor activity and has a potential role in the treatment of prostate cancer. The aim of this study was to document a new intracavitary applicator operating at 433 MHz, designed for transrectal hyperthermia, as well as to assess the specific absorption rate (SAR) distributions in terms of temperature measurements in a soft-tissue phantom. The microwave applicator consists of a dipole-type λ/2, a reflector, and the cooling system. The applicator was placed into a soft-tissue gel-phantom box that was mimicking the dielectric properties of the normal tissue. A calibrated thermometer was implanted inside the phantom at specific locations, to calculate temperature distributions. The maximum value of the SAR was 108 W/kg on the surface's central area at the footprint of the antenna, while the penetration depth was at around 3 cm. Our experimental measurements confirmed the role of the reflector concerning the directivity in a certain area and non icotropic, by means of protecting normal tissues around the prostate. The SAR experimental measurements showed that our applicator might be used effectively as a treatment device for prostate cancer, demonstrating a clear advantage over other similar transrectal devices. [ABSTRACT FROM AUTHOR]

Introduction – purposeThe aim of this study is to review the results of applying a hypofractionated radiotherapy schedule for locally advanced inoperable lung cancer in patients who have received chemotherapy. Lung cancer and especially non-small-cell lung cancer is prone to accelerated repopulation and shorter treatment schedules in the form of accelerated radiotherapy have been shown to improve treatment outcome.Patients – methodIn total, 29 patients with inoperable lung cancer (stage II, IIIa,b, IV) were treated with accelerated hypofractionated 3D conformal radiotherapy. All patients received a dose of 55 Gy in 20 fractions (daily dose of 2·75 Gy). The median age was 65·5 years, 87% of patients had stage III–IV disease, 93% of patients received sequential chemotherapy with their radiotherapy. Median follow-up of patients was 36 months.ResultsThe median overall survival from time of diagnosis was 16·5 months and the 1 year overall survival was 31%. Complications were present in 44·8% of the patients and the most common complication (20·7%) was pneumonitis alone. The complication rate was not significantly different according to histological type, stage, type of chemotherapy, presence of recurrence or death.ConclusionAlthough our study limitation is the small number of patients, these data suggest that the efficacy of this hypofractionated schedule could be considered as alternative option to the conventional regimen of 66 Gy given in 33 fractions. [ABSTRACT FROM PUBLISHER]

Glioblastoma remains a clinical challenge in spite of years of extensive research. Novel approaches are needed in order to integrate the existing knowledge. This is the potential role of mathematical oncology. This paper reviews mathematical models on glioblastoma from the clinical doctor's point of view, with focus on 3D modeling approaches of radiation response of in vivo glioblastomas based on contemporary imaging techniques. As these models aim to provide a clinically useful tool in the era of personalized medicine, the integration of the latest advances in molecular and imaging science and in clinical practice by the in silico models is crucial for their clinical relevance. Our aim is to indicate areas of GBM research that have not yet been addressed by in silico models and to point out evidence that has come up from in silico experiments, which may be worth considering in the clinic. This review examines how close these models have come in predicting the outcome of treatment protocols and in shaping the future of radiotherapy treatments. [ABSTRACT FROM AUTHOR]

Radiation therapy is an integral part of management in breast carcinoma treatment. Standard curative schedules of radiotherapy to the breast deliver 25 fractions of 2.0 Gy per day over 5DS6 weeks. Considerable recent literature suggests that hypo-fractionation may be advisory in breast cancer. The use of fewer fractions of more than 2 Gy per day (hypo-fractionation) is based on data suggesting that breast carcinoma is more sensitive to fraction size than squamous carcinomas and therefore could have similar fractionation sensitivity to the dose-limiting healthy tissues, including skin, subcutaneous tissues, muscle and ribs. In this article, a review of published studies and currently ongoing trials, which may provide evidence for the use of hypo-fractionated radiotherapy in breast cancer patients, is presented. Also, for all these different hypo-fractionation regimens found in literature, biologically effective dose (BED) values are calculated and compared. Data from studies and randomised trials seem to support the concept that modest hypo-fractionation can be used to treat the whole breast after breast-conserving surgery with similar rates of local control and radiation morbidity as seen with conventional fractionation. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate composite coplanar and non-coplanar three-dimensional conformal techniques (3D-CRT) for external-beam prostate radiotherapy using a low-energy (6 MV) photon beam. Methods and Materials: For treatment-planning purposes, three different planning target volumes (PTV) were defined for ten patients with prostate cancer and as follows: PTV1 (pelvis), PTV2 (prostate + seminal vesicles + 1 cm margin) and PTV3 (prostate + 1 cm margin). Conformal techniques of 2, 3, 4, 5 (coplanar) and 6 (non-coplanar) field techniques have been considered and combined to produce five different plan combinations (i.e. techniques A, B, C, D and E). Treatment plans were generated with a prescription dose of 75 Gy to PTV3, 65 Gy to PTV2 and 45 Gy to PTV1 and were assessed on the basis of 3D dose distributions and dose-volume histograms (DVHs). Normal tissue-dose constraints for the relevant organs at risk (OARs), that is, rectum, bladder and femoral heads, were also considered. Results: Findings show that all five treatment-plan combinations result in adequate PTV coverage and acceptable OAR irradiated volumes. The greatest rectal spacing in the high-dose region is achieved by technique C; all techniques achieve this, except for technique A, and give approximately the same fraction of volume (of rectum) that receives a dose of 50 Gy (V50) and 60 Gy (V60). When considering the bladder, techniques B, D and E give the best bladder sparing with small absolute differences, whereas technique A results in the lowest dose for femoral heads. Technique E appears to give the best compromise for all three considered OARs, provided the PTV is adequately covered. Conclusions: Even though the optimum photon-beam energy for conformal prostate radiotherapy is greater than 10 MV, our study shows that a good sparing of OAR can be achieved even with a lower-energy beam (6 MV) and the appropriate plan combination and that the dose to prostate can be as high as 75 Gy. [ABSTRACT FROM AUTHOR]

Purpose: To compare two hypofractionated radiation schedules in early breast cancer concerning skin toxicity., Methods: We retrospectively analyzed 80 patients (group A) versus 54 (group B) who underwent hypofractionated radiotherapy after breast conserving surgery. Group Α received 42.75Gy in 15 fractions over 5 weeks (3 fractions/ week) plus 8.55Gy boost to the tumor bed (3 fractions). Group Β received 45.05Gy (5 fractions/week) and 7.95Gy boost (3 fractions). Multivariate logistic regression analysis (MVLRA) was conducted for relevant parameters regarding RTOG/EORTC skin toxicity., Results: Median follow up was 60 months. Median age was 75 years (group A) and 56 (group B). Mean values of radio-dermatitis were significantly higher in group A vs B until 3 months post RT (p<0.001 and p=0.002, respectively), while 6 months thereafter toxicity was regressed without any significant difference between groups. MVLRA showed a significant (p<0.001) odds ratio for age (2.36, 95%CI:1.11-3.75) and group A (1.31, 95%CI:1.12-1.49)., Conclusion: Schedule B would be preferable in younger women in favor of toxicity. Schedule A could still be applied in elderly patients, unavailable attending daily schedules, with acceptable toxicity.

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.

Purpose: During the last years hyperthermia is a developing therapeutic modality in Greece. Quality assurance (QA) procedures are essential for ensuring the correct operation of the hyperthermia system and therefore the selective heating of the tumor with minimum toxicity to the surrounding healthy tissues. The European Society for Hyperthermic Oncology (ESHO) has proposed QA guidelines for superficial as well as deep hyperthermia systems. The purpose of this study was to describe the adapted QA protocol for superficial and deep hyperthermia systems established in Greece., Methods: A working group was created by the Hellenic Association of Medical Physicists (HAMP) for the proposal of QA guidelines for superficial and deep hyperthermia systems. A review of the protocol proposed by ESHO, together with the existing protocols in other European and International centers, as well as protocols suggested by European or International organizations, was performed. Then, a protocol was suggested, describing procedures for QA according to the current technology and the existing equipment used in Greece., Results: A protocol describing the procedures for QA of superficial and deep hyperthermia systems was proposed. These procedures aim to evaluate the correct operation of the device, the thermometric system, the generator, the incorporated power meter and the applicators. It will also ensure the electrical safety of the devices., Conclusions: The proposed protocol, applied by medical physicists in Greece, will ensure an efficient treatment with safety and minimum adverse effects. This protocol has been approved by the Hellenic Society of Oncologic Hyperthermia and the Hellenic Association of Medical Physicists.

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.

Purpose: Intensity Modulated Radiation Therapy (IMRT) is nowadays the treatment of choice, in terms of technique, for either head & neck or prostate cancer. With this paper, we are sharing our experience for the first inplementation of IMRT planning in the public sector in Greece, and especially in the Aretaieion University Hospital of Athens., Methods: From May 2013 until January 2014 four prostate and four head & neck cancer patients were evaluated in the present study. We used the ONCENTRA IMRT treatment planning with a step and shoot technique in a SIEMENS ONCORE Linac. The dose verification method used was based on the delta4(PT) Pre-Treatment volumetric quality assurance system, by Scadidos., Results: In all cases, the Relative Standard Deviation between the prescribed and the calculated average dose received by the target volume was less than 5%, while the γ-index was more than 90%. The acute toxicity was low and equivalent to published data with IMRT technique., Conclusion: In conclusion, the first implementation of IMRT technique in the Medical School of Athens was feasible and safe as well as in terms of dose verification. The IMRT technique is already in clinical use and further results with long term radiation induced toxicity will be reported.