Induced luminescence in water and PMMA - spectral analysis for irradiations with proton beams within the clinical energy range.

It was recently discovered that water and PMMA emit a weak luminescence signal when irradiated with protons within the clinically used energy range. This could offer a fast approach for range measurements in water. However, a complete explanation or investigation on the origin of the signal has not been published. In this work, a setup for the high-resolution spectral measurement of the weak luminescence signal in water and PMMA was designed. The measurement environment in the vicinity of a proton accelerator represented a major challenge for the sensitive optical measurements due to the presence of ionizing scattered radiation. A high-sensitive spectrometer in combination with a custom-made fiber was used to build a foundation for further analysis of the luminescence signal by providing accurate spectral information. For water, a broad distribution in the range from 240 to 900 nm with a maximum at 480 nm was obtained. A comparison of the spectra with previously published work indicates that the signal originates from excited states produced during the radiolysis of water. In comparison, differences between the water and the PMMA spectrum were observed. When examining the signal in PMMA, spectral differences were found compared to the measurements in water. The signal in PMMA was approximately 10 times stronger, had a narrower distribution and was shifted to lower wavelengths. Nevertheless, for the investigated proton energies, no spectral energy dependence was detected. In addition to the results for water and PMMA, a further luminescence signal was measured when the silica fiber used was directly irradiated with primary protons. All spectra, obtained in this work, describe the signal of proton-induced luminescence in water and PMMA with a high resolution of 3.4 nm and thus form a basis for further research, which could be a powerful tool in proton range verification.

Students' learning behavior in digital education for radiation oncology.

PURPOSE: Digitalization of medical education is an important trend in terms of reforming and modernizing the global education environment. It has been long requested by students and politicians. The goal of this study was to assess the student perception of a newly developed digital educational program in radiation oncology (RO) using an interactive e­book combined with short learnings clips on a YouTube channel combined with periodic videoconferences and a forum for queries. METHODS: We performed five evaluations during and at the end of two terms with multiple-choice and free-text answers. We evaluated student perception of our new digital learning scenario in three semesters: one pre-clinical and two clinical semesters. In addition, we analyzed all comments from the kMED forum, the YouTube channel, or the e­mail contacts. We analyzed the learning behavior of the students based on access to the videos and the number and quality of the reflective questions answered as well as the results of the final examinations. RESULTS: The students accepted the offer for asynchronous teaching and mainly learned on weekdays (74% of the videos), but also on weekends (23%) and less on public holidays (4%). The answer quality of the reflective questions was good with over 50% correct answers on the first attempt. Learning to be on one's own authority was very difficult for the students, even in the last clinical semesters of the medical study. Without direct intervention by the teacher, access to the learning material by the students was limited and delayed. Therefore, voluntary interim tests were performed during the first analysis term, which led to an increased number of student accesses to the videos and higher number of answers. Nevertheless, in the first analysis term, the average results in the final exam of the students who did not perform the interim test were below average at 59.1%, and the students who performed the test had better results at 69.5% but this was also not satisfactory. In the second analysis term, we taught with the same digital teaching model but with an additional scheme for learning over the term, 2­week compulsory intermediate tests, and frequent videoconferences to answer any questions. In this term, we measured a success rate of 93% in the final exam. All annotations were very positive regarding the new educational project. The evaluations showed high acceptance of the new education program. The students stated they would prefer the new education course to be continued in future. CONCLUSION: Digital teaching methods make not only the type and quality of teaching transparent, but also the learning behavior of the students. Our analysis has shown that, in addition to the quality of the teaching, the clear structure and specification of the learning content per learning week as well as regular monitoring of what has been learned are of decisive importance for the learning success of the students.

Experimental determination of modulation power of lung tissue for particle therapy.

In particle therapy of lung tumors, modulating effects on the particle beam may occur due to the microscopic structure of the lung tissue. These effects are caused by the heterogeneous nature of the lung tissue and cannot be completely taken into account during treatment planning, because these micro structures are too small to be fully resolved in the planning CT. In several publications, a new material parameter called modulation power (Pmod) was introduced to characterize the effect. For various artificial lung surrogates, this parameter was measured and published by other groups and ranges up to approximately 1000µm. Studies investigating the influence of the modulation power on the dose distribution during irradiation are using this parameter in the rang of 100-800µm. More precise measurements forPmodon real lung tissue have not yet been published. In this work, the modulation power of real lung tissue was measured using porcine lungs in order to produce more reliable data ofPmodfor real lung tissue. For this purpose,ex-vivoporcine lungs were frozen in a ventilated state and measurements in a carbon ion-beam were performed. Due to the way the lungs were prepared and transferred to a solid state, the lung structures that modulate the beam could also be examined in detail using micro CT imaging. An optimization of the established methods of measuring the modulation power, which takes better account of the typical structures within lung tissue, was developed as well.

Estimating the modulating effect of lung tissue in particle therapy using a clinical CT voxel histogram analysis.

To treat lung tumours with particle therapy, different additional tasks and challenges in treatment planning and application have to be addressed thoroughly. One of these tasks is the quantification and consideration of the Bragg peak (BP) degradation due to lung tissue: as lung is an heterogeneous tissue, the BP is broadened when particles traverse the microscopic alveoli. These are not fully resolved in clinical CT images and thus, the effect is not considered in the dose calculation. In this work, a correlation between the CT histograms of heterogeneous material and the impact on the BP curve is presented. Different inorganic materials were scanned with a conventional CT scanner and additionally, the BP degradation was measured in a proton beam and was then quantified. A model is proposed that allows an estimation of the modulation power by performing a histogram analysis on the CT scan. To validate the model for organic samples, a second measurement series was performed with frozen porcine lunge samples. This allows to investigate the possible limits of the proposed model in a set-up closer to clinical conditions. For lung substitutes, the agreement between model and measurement is within ±0.05 mm and for the organic lung samples, within ±0.15 mm. This work presents a novel, simple and efficient method to estimate if and how much a material or a distinct region (within the lung) is degrading the BP on the basis of a common clinical CT image. Up until now, only a direct in-beam measurement of the region or material of interest could answer this question.

Optical range determination of clinical proton beams in water. A comparison with standard measurement methods.

As recently discovered, water emits a weak luminescence when it is irradiated with protons even with energies below the Cerenkov light threshold. In this work it was investigated if this phenomenon could be exploited for range measurements in proton therapy. A measurement setup based on a scientific CMOS camera that can be operated under normal room light was built and tested in a proof-of-principle experiment at the West German Proton Therapy Center, Essen. The luminescence depth profiles were analyzed to obtain the range information and the method was compared with ionization chamber based depth dose measurements. The noise caused by scattered radiation hitting the camera chip could be removed with a simple threshold-based median filter. The influence of Cerenkov radiation produced by delta electrons was analyzed by FLUKA simulations and it was shown that it does not affect the range measurements. It could be shown that the luminescence method is as fast as the multi-layer ionization chamber measurement (a few seconds) but with a higher depth resolution that is comparable with the Bragg peak chamber method. The proton ranges determined with the luminescence method agree with the reference methods better than 0.2% over the whole energy range 100-226MeV. The sensitivity of the method regarding detectable range shifts was tested. It was shown, that energy shifts of 0.5MeV (at 151MeV), leading to a range shift of ∼0.9mm, were clearly detectable.

Fluence-weighted average subfield size in helical TomoTherapy.

INTRODUCTION: Helical TomoTherapy allows a highly conformal dose distribution to complex target geometries with a good protection of organs at risk. However, the small field sizes associated with this method are a possible source of dosimetrical uncertainties. The IAEA has published detector-specific field output correction factors for static fields of the TomoTherapy in the TRS483. This work investigates the average subfield size of helical TomoTherapy plans. MATERIAL AND METHODS: A new parameter for helical TomoTherapy was defined - the fluence-weighted average subfield size. The subfield sizes were extracted from the leaf-opening time sinograms in the RT-plan files for 30 clinical prostate and head and neck plans and were put in relation to Delat4 Phantom+ measurement results. Additionally the influence of planning parameters on the subfield size was studied by varying the modulation factor, number of iterations and pitch in the dose optimization and calculation for three different clinical indications H&N, prostate and rectum cancer. Selected plans were dosimetrically verified by Delta4 measurements to examine the reliability in dependence of the average subfield size. Furthermore, the impact of the planning parameters on a) the dose distribution, with regard to the planning target volume and regions at risks, and b) machine characteristics such as delivery time, actual modulation factor and leaf-opening times were evaluated. RESULTS: The average equivalent square subfield lengths (s¯eq) of the two investigated indications did not differ significantly - prostate plans: 2.75±0.14cm and H&N plans: 2.70±0.16cm, both with a jaw width of 2.5cm. No correlation between field size and measured dose deviation was detected. The number of iterations and the modulation factor have a considerable influence on the average subfield size. The higher the planned modulation factor and the more iterations are used during optimization, the smaller is the subfield size. In our pilot study plans were calculated with field sizes s¯eq between 4.2cm and 1.7cm, with a jaw width of 2.5cm. Again, the measurement results of Delta4 showed no significant deviation from the doses calculated by the TomoTherapy planning system for the whole range of subfield sizes, and no significant correlation between field sizes and dose deviations was found. As expected, the clinical dose distribution improved with increasing modulation factor and an increasing number of iterations. The compromise between an improved dose distribution and smaller s¯eq was shown. CONCLUSION: In this work, a method was presented to determine the average subfield size for helical TomoTherapy plans. The response of the Delta4 did not show any dependence on field size in the range of the field sizes covered by the studied plans. The influence of the subfield sizes on other dosimetry systems remains to be investigated.

Palliative care in everyday practice of radiation oncologists : Results from a web-based survey among medical members of the German Society for Radiation Oncology (DEGRO).

PURPOSE: Little is known about the attitudes of radiation oncologists towards palliative care, about their competences in this field, and about the collaboration with palliative care specialists. Our aim was to close this gap and understand more about the importance of an additional qualification in palliative care. METHODS: Medical members of the German Society for Radiation Oncology (DEGRO) were electronically surveyed during November-December 2016. RESULTS: The survey was emailed successfully to 1110 addressees, whereas a total of 205 questionnaires were eligible for analysis (response rate 18.4%). 55 (26.8%) of the respondents had an additional qualification in palliative care. Physicians who had an additional qualification in palliative care (PC qualification) reported palliative care needs for their patients more frequently than the other respondents (89.0 vs. 82.7%, p = 0.008). Furthermore, they were most likely to report a high confidence in palliative care competences, such as "communication skills & support for relatives" (83.6 vs. 59.3%, p = 0.013), "symptom control," and "pain management" (94.5 vs. 67.7%, p < 0.001 and 90.9 vs. 73.3%, p = 0.008, respectively). Respondents with a PC qualification more often involved palliative care specialists than the other respondents (63.3 vs. 39.3%, p = 0.007). Perceived main barriers regarding palliative care in radiation oncology included time aspects (9.2%), stigmata (8.5%), and the lack of interdisciplinary collaboration (8.5%). CONCLUSIONS: This analysis demonstrated that aspects of palliative care strongly impact on daily practice in radiation oncology. Additional qualifications and comprehensive training in palliative medicine may contribute to improved patient care in radiation oncology.

Impact of Different Treatment Concepts on Regional Failure in Advanced Oropharyngeal Cancer.

BACKGROUND: The management of patients with advanced oropharyngeal cancer is complex and mostly requires a multidisciplinary treatment approach. In general, organ preservation by primary concurrent radiochemotherapy (RCT), or surgery completed by adjuvant radiotherapy are established treatment strategies for these patients. However, it is unclear if primary treatment has an effect on regional tumor control. The purpose of the present study was to evaluate the regional control after different treatment concepts. PATIENTS AND METHODS: Clinical data, including histological and radiological results, of 82 patients with T2-T3 oropharyngeal cancer and N2 neck were retrospectively analyzed. They underwent either RCT with salvage neck dissection (ND) (n=45), or primary transoral surgery with ND and adjuvant RCT (n=37). In all cases, the primary tumor was successfully treated, without evidence of local failure in the follow-up. RESULTS: Overall, 11 (13.4%) patients developed regional failure during the follow-up. There were no significant differences in frequency of regional failure (p=0.75), distant metastasis (p=0.35) and overall survival (p=0.22) between treatment groups. However, 5-year disease-free survival was significantly worse (39.0% vs. 57.0%) for patients treated by RCT, with more frequent regional failure detected compared to surgically-treated patients in univariate analysis (p=0.04). CONCLUSION: Treatment concept does not seem to affect regional tumor control in advanced oropharyngeal cancer after successful treatment of the primary tumor.

Patient's quality of life after high-dose radiation therapy for thoracic carcinomas : Changes over time and influence on clinical outcome.

PURPOSE: Quality of life (QoL) is an important factor in patient care. This analysis is focused on QoL before and after radio(chemo)therapy in patients with thoracic carcinomas, as well as on its influence on clinical follow-up and survival, and the correlation with treatment-related toxicities. MATERIALS AND METHODS: The analysis included 81 patients with intrathoracic carcinoma receiving radio(chemo)therapy. For analysis of QoL, the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and the lung cancer-specific supplement (EORTC QLQ-LC13) were used. QoL data were collected before radiation treatment (RT), and 6 weeks, 12 weeks, 6 months, and 12 months after RT. Other factors were additionally analyzed, including clinical outcome, survival, and side effects. RESULTS: The functional scales showed maximum values or at least a recovery 12 weeks after RT. Symptoms with a high mean symptom score (> 40) at all appointments were fatigue, dyspnea, and coughing. Insomnia, peripheral neuropathy, appetite loss, dyspnea (from QLQ-LC13), and all pain parameters had an intermediate mean score (10-40). There were low mean scores of < 10 for nausea and vomiting, diarrhea, sore mouth, and hemoptysis. There was a significant correlation between clinical dysphagia and radiation pneumonitis with the associated symptom scales. None of the QoL scores had a significant influence on local and distant control or survival. CONCLUSION: 12 weeks after RT the QLQ-C30 functional scales show the highest scores or at least a temporary recovery. The symptom scales accurately reflect the common symptoms and treatment-related toxicities. QoL did not prove to be a significant predictor for local and distant control or survival.

Changes in pulmonary function and influencing factors after high-dose intrathoracic radio(chemo)therapy.

PURPOSE: Using prospectively collected patient-related, dose-related, and pulmonary function test (PFT) data before radiotherapy (RT) and at several follow-up visits after RT, the time course of PFT changes after high-dose radio(chemo)therapy and influencing factors were analyzed. MATERIALS AND METHODS: From April 2012 to October 2015, 81 patients with non-small-cell lung carcinoma (NSCLC), small cell lung carcinoma (SCLC), or esophageal carcinoma where treated with high-dose radio(chemo)therapy. PFT data were collected before treatment and 6 weeks, 12 weeks, and 6 months after RT. The influence of patient- and treatment-related factors on PFT was analyzed. RESULTS: Mean forced expiratory volume in 1 s (FEV1) constantly declined during follow-up (p = 0.001). In total, 68% of patients had a reduced FEV1 at 6 months. Mean vital capacity (VC) didn't change during follow-up (p > 0.05). Mean total lung capacity (TLC) showed a constant decline after RT (p = 0.026). At 6 months, 60% of patients showed a decline in VC and 73% in TLC. The mean diffusion capacity for carbon monoxide (DLCO) declined at 6 and 12 weeks, but recovered slightly at 6 months (p < 0.0005). At 6 months, 86% of patients had a reduced DLCO. After treatment, the partial pressure of CO2 in the blood (pCO2) was increased and pO2 was decreased (p > 0.05). Only the pretreatment PFT classification had a significant influence on the post-RT FEV1. CONCLUSION: DLCO seems to be the most reliable indicator for lung tissue damage after thoracic RT. Ventilation parameters appear to be less reliable. Concerning patient- or treatment-related factors, no reliable conclusion can be drawn regarding which factors may be relevant.

A lot to a little or a little to a lot-which dose-volume relationship ensures the best clinical outcome in the high dose radiation therapy of thoracic tumors? A prospective approach.

BACKGROUND: The purpose of this prospective randomized trial is to determine which constellation of dose and corresponding volume of the lung tissue-either a lot to a little or a little to a lot-should be preferred to ensure the best possible outcome for patients with thoracic carcinomas. METHODS: From Apr 2012 to Oct 2015, 81 patients with NSCLC, SCLC or esophageal carcinoma were randomized and treated with either a 4-field-IMRT or a VMAT technique with or without additional chemotherapy. Data regarding clinical outcome, pulmonary function tests (PFT) and quality of life (QoL) was collected before RT, 6 weeks, 12 weeks and 6 months after treatment, QoL data additionally 1 year post RT. Follow up CTs were done 12 weeks and 6 months after RT. RESULTS: There is no significant difference regarding the local (P=0.954) and distant (P=0.206) outcome, side effects (all P>0.05) or survival (P=0.633) at any follow-up appointment. The comparison of the PFT shows a statistically significant difference for the DLCO 6 weeks post RT (P=0.028). All other parameters do not differ significantly at any follow up appointment. Regarding the QoL there is no statistically significant difference at any follow up appointment (P>0.1). There is a statistically significant difference between the mean density of the lung parenchyma at 12 weeks (P<0.0005) and 6 months post RT (P<0.0005). CONCLUSIONS: Since there is no significant and relevant difference between both treatment arms regarding PFT, clinical outcome and QoL it does not seem to relevant how the DVH is shaped exactly as long as established dose constraints for the organs at risk are respected. As to whether the difference between the CT density changes is clinically relevant further analysis is needed.

Making the right software choice for clinically used equipment in radiation oncology.

The customer of a new system for clinical use in radiation oncology must consider many options in order to find the optimal combination of software tools. Many commercial systems are available and each system has a large number of technical features. However an appraisal of the technical capabilities, especially the options for clinical implementations, is hardly assessable at first view.The intention of this article was to generate an assessment of the necessary functionalities for high precision radiotherapy and their integration in ROKIS (Radiation oncology clinic information system) for future customers, especially with regard to clinical applicability. Therefore we analysed the clinically required software functionalities and divided them into three categories: minimal, enhanced and optimal requirements for high conformal radiation treatment.

Guidelines for delineation of lymphatic clinical target volumes for high conformal radiotherapy: head and neck region.

The success of radiotherapy depends on the accurate delineation of the clinical target volume. The delineation of the lymph node regions has most impact, especially for tumors in the head and neck region. The purpose of this article was the development an atlas for the delineation of the clinical target volume for patients, who should receive radiotherapy for a tumor of the head and neck region. Literature was reviewed for localisations of the adjacent lymph node regions and their lymph drain in dependence of the tumor entity. On this basis the lymph node regions were contoured on transversal CT slices. The probability for involvement was reviewed and a recommendation for the delineation of the CTV was generated.

Dose uncertainty in radiotherapy of patients with head and neck cancer measured by in vivo ESR/alanine dosimetry using a mouthpiece.

In order (i) to evaluate the dose uncertainty of the mouthpiece in daily use during intensity-modulated radiotherapy of patients with head and neck cancer, and (ii) to present a system for in vivo dosimetry of the oral mucosa, we equipped the mouthpiece with alanine dosimeter probes for in vivo dosimetry. The aim was to determine the dose uncertainty caused by the daily positioning of the mouthpiece during dynamic treatment techniques. During IMRT radiotherapy of patients with head and neck cancer, the doses accumulated next to the mucosa were measured in five patients and compared to the dose calculated by the treatment planning system. The comparison of the applied and measured dose for each measurement point showed in six of the eight alanine probe positions a good agreement within the given relative combined standard uncertainty of less than 4.5% for a accumulated dose of 30 Gy and less than 4.6% for an accumulated dose of 8 Gy, respectively. In two of the eight alanine probe positions the applied and measured doses differed by 7.7% and 8.2% from each other. The dominant contribution to the overall uncertainty for the in vivo measurements was the positioning of the dosimeter probes in the patient's body and their corresponding localization in the CT data as well as the inaccuracy of the available algorithm for dose distribution calculation at the low-density material/soft tissue interface between the mouthpiece and the mucosa. Regarding our results, we refrain from the use of a mouthpiece during dynamic treatments such as IMRT.

Two years experience with quality assurance protocol for patient related Rapid Arc treatment plan verification using a two dimensional ionization chamber array.

PURPOSE: To verify the dose distribution and number of monitor units (MU) for dynamic treatment techniques like volumetric modulated single arc radiation therapy-Rapid Arc-each patient treatment plan has to be verified prior to the first treatment. The purpose of this study was to develop a patient related treatment plan verification protocol using a two dimensional ionization chamber array (MatriXX, IBA, Schwarzenbruck, Germany). METHOD: Measurements were done to determine the dependence between response of 2D ionization chamber array, beam direction, and field size. Also the reproducibility of the measurements was checked. For the patient related verifications the original patient Rapid Arc treatment plan was projected on CT dataset of the MatriXX and the dose distribution was calculated. After irradiation of the Rapid Arc verification plans measured and calculated 2D dose distributions were compared using the gamma evaluation method implemented in the measuring software OmniPro (version 1.5, IBA, Schwarzenbruck, Germany). RESULTS: The dependence between response of 2D ionization chamber array, field size and beam direction has shown a passing rate of 99% for field sizes between 7 cm×7 cm and 24 cm×24 cm for measurements of single arc. For smaller and larger field sizes than 7 cm×7 cm and 24 cm×24 cm the passing rate was less than 99%. The reproducibility was within a passing rate of 99% and 100%. The accuracy of the whole process including the uncertainty of the measuring system, treatment planning system, linear accelerator and isocentric laser system in the treatment room was acceptable for treatment plan verification using gamma criteria of 3% and 3 mm, 2D global gamma index. CONCLUSION: It was possible to verify the 2D dose distribution and MU of Rapid Arc treatment plans using the MatriXX. The use of the MatriXX for Rapid Arc treatment plan verification in clinical routine is reasonable. The passing rate should be 99% than the verification protocol is able to detect clinically significant errors.

High-grade acute organ toxicity as a positive prognostic factor in primary radiochemotherapy for anal carcinoma.

PURPOSE: To test for a possible correlation between high-grade acute organ toxicity during primary radiochemotherapy and treatment outcome for patients with anal carcinoma. METHODS AND MATERIALS: From 1991 to 2009, 72 patients with anal carcinoma were treated at our department (10 patients had stage I, 28 patients had stage II, 11 patients had stage IIIA, and 13 patients had stage IIIB cancer [Union Internationale Contre le Cancer criteria]). All patients received normofractionated (1.8 Gy/day, five times/week) whole-pelvis irradiation including iliac and inguinal lymph nodes with a cumulative dose of 50.4 Gy. Concomitant chemotherapy regimen consisted of two cycles of 5-fluorouracil (1,000 mg/m(2)total body surface area (TBSA)/day as continuous intravenous infusion on days 1-4 and 29-32) and mitomycin C (10 mg/m(2)/TBSA, intravenously on days 1 and 29). Toxicity during treatment was monitored weekly, and any incidence of Common Toxicity Criteria (CTC) grade of ≥3 for skin reaction, cystitis, proctitis, or enteritis was assessed as high-grade acute organ toxicity for later analysis. RESULTS: We found significant correlation between high-grade acute organ toxicity and overall survival, locoregional control, and stoma-free survival, which was independent in multivariate analysis from other possible prognostic factors: patients with a CTC acute organ toxicity grade of ≥3 had a 5-year overall survival rate of 97% compared to 30% in patients without (p < 0.01, multivariate analysis; 97% vs. 48%, p = 0.03 for locoregional control, and 95% vs. 59%, p = 0.05 for stoma-free survival). CONCLUSIONS: Our data indicate that normal tissue and tumor tissue may behave similarly with respect to treatment response, since high-grade acute organ toxicity during radiochemotherapy showed itself to be an independent prognostic marker in our patient population. This hypothesis should be further analyzed by using biomolecular and clinical levels in future clinical trials.

Single fraction radiosurgery using Rapid Arc for treatment of intracranial targets.

BACKGROUND: Stereotactic-Radio-Surgery (SRS) using Conformal-Arc-Therapy (CAT) is a well established irradiation technique for treatment of intracranial targets. Although small safety margins are required because of very high accuracy of patient positioning and exact online localisation, there are still disadvantages like long treatment time, high number of monitor units (MU) and covering of noncircular targets. This planning study analysed whether Rapid Arc (RA) with stereotactic localisation for single-fraction SRS can solve these problems. METHODS: Ten consecutive patients were treated with Linac-based SRS. Eight patients had one or more brain metastases. The other patients presented a symptomatic vestibularis schwannoma and an atypic meningioma. For all patients, two plans (CAT/RA) were calculated and analysed. RESULTS: Conformity was higher for RA with additional larger low-dose areas. Furthermore, RA reduced the number of MU and the treatment time for all patients. Dose to organs at risk were equal or slightly higher using RA in comparison to CAT. CONCLUSIONS: RA provides a new alternative for single-fraction SRS irradiation combining advantages of short treatment time with lower number of MU and better conformity in addition to accuracy of stereotactic localisation in selected cases with uncomplicated clinical realization.

Influence of irradiated lung volumes on perioperative morbidity and mortality in patients after neoadjuvant radiochemotherapy for esophageal cancer.

PURPOSE: In some randomized trials, the treatment outcome of locally advanced esophageal cancer has been significantly improved by neoadjuvant radiochemotherapy (RCT). However, increased perioperative pulmonary toxicity in terms of acute respiratory distress syndrome (ARDS) has been linked to radiation exposure of the lungs. In our study we evaluated perioperative morbidity and mortality in patients with cancer Stages IIA-IVA treated with curative intent either with surgery alone (S) or with neoadjuvant RCT followed by surgery (RCTS). PATIENTS AND METHODS: Between 1996 and 2003, 55 patients received S, and 98 received RCTS. In the RCTS group, most patients received two cycles of 5-fluorouracil plus cisplatinum simultaneously with normofractionated radiotherapy (40Gy). Four weeks later they underwent surgery. Endpoints were the incidence of acute lung injury (ALI), ARDS, other postoperative complications, and mortality within 31 days. RESULTS: Between both groups there were no significant differences between the incidence and severity of ALI and ARDS (RCTS: 42.9%, 42.9%; S: 45.5%, 38.2%). Furthermore, there were no significant differences in the incidences of pneumonia, pleural effusion, and pneumothorax (RCTS 29.6% vs. S 16.4%, p = 0.07). Perioperative complication rates and mortality did not vary significantly (mortality after RCTS 5.1% vs. S 3.6%). A detailed analysis of 54 RCTS patients according to lung dose-volume histograms did not show any correlation between ARDS and pulmonary exposure. In univariate analysis, only respiratory comorbidity correlated with ARDS. CONCLUSION: Neoadjuvant cisplatinum and 5-fluorouracil-based RCT apparently has no detrimental impact on the postoperative course.

Nasopharyngeal carcinoma in adults: treatment results after long-term follow-up with special reference to adjuvant interferon-beta in undifferentiated carcinomas.

PURPOSE: Nasopharyngeal carcinomas (NPC) are radiosensitive, and radiotherapy is the standard curative treatment. Furthermore, it has been shown that combined radiochemotherapy improves prognosis in locally advanced stages. Further encouraging results have been obtained with adjuvant interferon-beta after primary radio(chemo)therapy in childhood undifferentiated NPC. Aim of the present study was to evaluate the treatment results after long-term follow-up after radio(chemo)therapy for adult NPC with special reference to patients with undifferentiated carcinomas treated with adjuvant interferon-beta. PATIENTS AND METHODS: From 02/1992 to 07/2008, 26 adult patients with NPC without distant metastases were treated (17 squamous cell carcinomas, 9 undifferentiated carcinomas). The treatment concepts changed over the years: 13 patients were treated with radiotherapy alone, 13 patients received combined radiochemotherapy. Additionally, six patients with undifferentiated carcinomas were treated with adjuvant interferon-beta after radiochemotherapy for 6 months. RESULTS: After a median follow-up of 96 months, 17 patients remain alive. Collectively, our 5-year overall-survival and loco-regional control rates were 74% (radiochemotherapy 81%, radiotherapy alone 68.5%) and 87% (radiochemotherapy 100%, radiotherapy alone 72.7%), respectively. All treatment regimens used were feasible; especially, adjuvant interferon-beta was applied as provided without high grade toxicity. All patients with undifferentiated carcinomas treated with adjuvant interferon-beta stayed alive until the end of the follow-up. CONCLUSION: In summary, our data affirm that NPC in adults are curable by primary radio(chemo)therapy. Furthermore, our data indicate that adjuvant interferon-beta application in undifferentiated NPC in adults is feasible and shows promising results. Further prospective clinical trials are needed to finally establish adjuvant interferon beta in curative treatment of adult NPC.