Durvalumab impacts progression-free survival while high-dose radiation >66 Gy improves local control without excess toxicity in unresectable NSCLC stage III: Real-world data from the Austrian radio-oncological lung cancer study association registry (ALLSTAR)

BACKGROUND

Chemo-radioimmunotherapy with total radiation doses of 60-66 Gy in 2 Gy fractions is the standard of care for non-small cell lung cancer (NSCLC) UICC stage III. The Austrian radio-oncological lung cancer study association registry (ALLSTAR) is a prospective multicentre registry intended to document clinical practice at the beginning of the Durvalumab era.

PATIENTS AND METHODS

Patients were eligible if they had pathologically verified unresectable NSCLC stage III with a curative treatment option. Chemo-radiation combined with immunotherapy was performed according to local treatment practices. The endpoints were local control (LC), progression-free survival (PFS) and toxicity.

RESULTS

Between 2020/03 and 2023/04, 12/14 (86 %) Austrian radiation-oncology centres recruited 188 patients (median 17, range: 1-89). PD-L1 testing was performed in 173/188 (93 %) patients. The median interval between the end of chemoradiotherapy and start of Durvalumab was 14 days (range: 1-65). About 40 % (75/188) of the patients received a total radiation dose of > 66 Gy (range: 67.1-100), which improved 2-year LC (86 % versus 60 %, HR = 0.41; 95 %-CI: 0.17-0.98; log-rank p-value < 0.05). Median PFS for patients with Durvalumab was 25.8 months (95 %-CI: 21.9-not reached) compared to 15.7 months (95 %-CI: 13.2-27.8) for those without (HR = 1.88; 95 %-CI: 1.16-3.05; log-rank p-value < 0.01). The rates of esophageal and pulmonary toxicities were 34.6 % and 23.9 %, respectively, including one case of grade 4 pneumonitis. In the subcohort of 75 patients who received > 66 Gy, 19 (25 %) cases of pulmonary toxicity grades 1-3 were observed.

CONCLUSION

While Durvalumab impacts PFS, LC can be improved by total radiation doses > 66 Gy without excess toxicity.

Pretreatment 18-FDG-PET/CT parameters can serve as prognostic imaging biomarkers in recurrent NSCLC patients treated with reirradiation-chemoimmunotherapy

BACKGROUND AND PURPOSE

Our study aimed to assess whether quantitative pretreatment 18F-FDG-PET/CT parameters could predict prognostic clinical outcome of recurrent NSCLC patients who may benefit from ablative reirradiation.

MATERIALS AND METHODS

Forty-eight patients with recurrent NSCLC of all UICC stages who underwent ablative thoracic reirradiation were analyzed. Twenty-nine (60%) patients received immunotherapy with or without chemotherapy in addition to reirradiation. Twelve patients (25%) received reirradiation only and seven (15%) received chemotherapy and reirradiation. Pretreatment 18-FDG-PET/CT was mandatory in initial diagnosis and recurrence, based on which volumetric and intensity quantitative parameters were measured before reirradiation and their impact on overall survival, progression-free survival, and locoregional control was assessed.

RESULTS

With a median follow-up time of 16.7 months, the median OS was 21.8 months (95%-CI: 16.2-27.3). On multivariate analysis, OS and PFS were significantly influenced by MTV (p < 0.001 for OS; p = 0.006 for PFS), TLG (p < 0.001 for OS; p = 0.001 for PFS) and SUL peak (p = 0.0024 for OS; p = 0.02 for PFS) of the tumor and MTV (p = 0.004 for OS; p < 0.001 for PFS) as well as TLG (p = 0.007 for OS; p = 0.015 for PFS) of the metastatic lymph nodes. SUL peak of the tumor (p = 0.05) and the MTV of the lymph nodes (p = 0.003) were only PET quantitative parameters that significantly impacted LRC.

CONCLUSION

Pretreatment tumor and metastastic lymph node MTV, TLG and tumor SUL peak significantly correlated with clinical outcome in recurrent NSCLC patients treated with reirradiation-chemoimmunotherapy.

Chemo-Radio-Immunotherapy for NSCLC III: ESR/ATS Thresholds for DLCO Correlate with Radiation Dosimetry and Pneumonitis Rate

Introduction: Durvalumab following chemoradiotherapy (CRT) for non-small cell lung cancer stage III has become the standard of care (SoC) in the past few years. With this regimen, 5-year overall survival (OS) has risen to 43%. Therefore, adequate pulmonary function (PF) after treatment is paramount in long-term survivors. In this respect, carbon monoxide diffusing capacity (DLCO), which represents the alveolar compartment, seems to be a suitable measure for residual lung capacity. The aim of the current analysis was to correlate DLCO with pneumonitis and radiation dose. Patients and methods: One hundred and twelve patients with histologically confirmed NSCLC III treated between 2015/10 and 2022/03 were eligible for this study. Patients received two cycles of platinum-based induction chemotherapy followed by high-dose radiotherapy (RT). As of 2017/09, durvalumab maintenance therapy was administered for one year. The clinical endpoints were based on the thresholds jointly published by the European Respiratory Society (ERS) and the American Thoracic Society (ATS). Pre-treatment DLCO of 60% was correlated to the incidence of pneumonitis, whereas the post-treatment DLCO decline of 10% was related to radiation dose. Results: Patients with a pre-treatment DLCO < 60% had a higher probability of pneumonitis (n = 98; r = 0.175; p-value 0.042), which could be reproduced in the subgroup of patients who did not receive durvalumab (n = 40; r = 0.288; p-value 0.036). In these individuals, the decline in DLCO ≥ 10% depended significantly on the size of the lung volume receiving between 45% and 65% (V65–45%) of the total radiation dose (r = 0.354; p-value = 0.020) and V20 Total Lung (r = 0.466; corrected p-value = 0.042). Conclusions: The current analysis revealed that DLCO is a predictor for clinically relevant pneumonitis and a monitoring tool for post-treatment lung function as it correlates with radiation dose. This underlines the importance of peri-treatment lung function testing.

Durvalumab after Sequential High Dose Chemoradiotherapy versus Standard of Care (SoC) for Stage III NSCLC: A Bi-Centric Trospective Comparison Focusing on Pulmonary Toxicity

Introduction: The standard of care (SoC) for unresectable stage III non-small-cell lung cancer (NSCLC) is durvalumab maintenance therapy after concurrent chemoradiation in patients with PD-L1 > 1%. However, the concurrent approach is only amenable for about one-third of patients due to co-morbidities. Although sequential regimens are usually not regarded as curative, these schedules applied in a dose-escalated manner may be similarly radical as SoC. As combining high-dose radiation and durvalumab remains a question of debate this retrospective bi-center study aims to evaluate pulmonary toxicity after high-dose chemoradiotherapy beyond 70 Gy compared to SoC. Patients and Methods: Patients with NSCLC stage III received durvalumab after either sequential high-dose chemoradiation or concomitant SoC. Chemotherapy consisted of platinum combined with either pemetrexed, taxotere, vinorelbine, or gemcitabine. The primary endpoint was short-term pulmonary toxicity occurring within six months after the end of radiotherapy (RT). Results: A total of 78 patients were eligible for this analysis. 18F-FDG-PET-CT, cranial MRT, and histological/cytological verification were mandatory in the diagnostic work-up. The high-dose and SoC group included 42/78 (53.8%) and 36/78 (46.2%) patients, respectively, which were matched according to baseline clinical variables. While the interval between the end of RT and the start of durvalumab was equal in both groups (p = 0.841), more courses were administered in the high-dose cohort (p = 0.031). Pulmonary toxicity was similar in both groups (p = 0.599), whereas intrathoracic disease control was better in the high-dose group (local control p = 0.081, regional control p = 0.184). Conclusion: The data of this hypothesis-generating study suggest that sequential high-dose chemoradiation followed by durvalumab might be similar to SoC in terms of pulmonary toxicity and potentially more effective with respect to intra-thoracic disease control. Larger trials with a prospective design are warranted to validate these results.

Impact of reirradiation, chemotherapy, and immunotherapy on survival of patients with recurrent lung cancer: A single-center retrospective analysis

Background

Given the limited curative treatment options for recurrent lung cancer patients, the aim of our retrospective study was to investigate whether these patients would benefit in terms of overall survival (OS) by adding immunotherapy to high‐dose reirradiation.

Materials and methods

Between 2013 and 2019, 47 consecutive patients with in‐field tumor recurrence underwent high‐dose thoracic reirradiation at our institute. Twenty patients (43%) received high‐dose reirradiation only, while 27/47 (57%) additionally had systemic therapy (immunotherapy and/or chemotherapy). With the exception of one patent, the interval between first and second radiation was at least 9 months. All patients had an Eastern cooperative oncology group ≤2. The diagnostic work‐up included a mandatory fluorodeoxyglucose‐positron emission tomography‐computed tomography scan and histological verification. The primary endpoint was OS after completion of the second course of irradiation.

Results

In the whole cohort of 47 patients, the median overall survival (mOS) after reirradiation was 18.9 months (95% confidence interval [CI] 16.5–21.3 months), while in the subgroup of 27 patients who received additional systemic treatment after reirradiation, mOS amounted to 21.8 months (95% CI 17.8–25.8 months). Within this group the comparison between reirradiation combined with either immunotherapy (n = 21) or chemotherapy (n = 6) revealed a difference in OS, which was in favor of the first (log‐rank p value = 0.063). Three patients (11%) experienced acute side effects and one (4%) showed a late hemorrhage grade 3.

Conclusion

Patients who received immunotherapy and reirradiation lived longer than those who did not receive immunotherapy.

Hsa-miR-375/RASD1 Signaling May Predict Local Control in Early Breast Cancer

Background: In order to characterize the various subtypes of breast cancer more precisely and improve patients selection for breast conserving therapy (BCT), molecular profiling has gained importance over the past two decades. MicroRNAs, which are small non-coding RNAs, can potentially regulate numerous downstream target molecules and thereby interfere in carcinogenesis and treatment response via multiple pathways. The aim of the current two-phase study was to investigate whether hsa-miR-375-signaling through RASD1 could predict local control (LC) in early breast cancer. Results: The patient and treatment characteristics of 81 individuals were similarly distributed between relapse (n = 27) and control groups (n = 54). In the pilot phase, the primary tumors of 28 patients were analyzed with microarray technology. Of the more than 70,000 genes on the chip, 104 potential hsa-miR-375 target molecules were found to have a lower expression level in relapse patients compared to controls (p-value < 0.2). For RASD1, a hsa-miR-375 binding site was predicted by an in silico search in five mRNA-miRNA databases and mechanistically proven in previous pre-clinical studies. Its expression levels were markedly lower in relapse patients than in controls (p-value of 0.058). In a second phase, this finding could be validated in an independent set of 53 patients using ddPCR. Patients with enhanced levels of hsa-miR-375 compared to RASD1 had a higher probability of local relapse than those with the inverse expression pattern of the two markers (log-rank test, p-value = 0.069). Conclusion: This two-phase study demonstrates that hsa-miR-375/RASD1 signaling is able to predict local control in early breast cancer patients, which—to our knowledge—is the first clinical report on a miR combined with one of its downstream target proteins predicting LC in breast cancer.

Radiation dose escalation with modified fractionation schedules for locally advanced NSCLC: A systematic review

Concomitant chemo‐radiotherapy (cCRT) with 60 Gy in 30 fractions is the standard of care for stage 111 non‐small cell lung cancer (NSCLC). With a median overall survival of 28.7 months at best and maximum locoregional control rates of 70% at two years, the prognosis for these patients is still dismal. This systematic review summarizes data on dose escalation by alternative fractionation, which has been explored as a primary strategy to improve both local control and overall survival over the past three decades. A Pubmed literature search was performed according to the PRISMA guidelines. Because of the large variety of radiation regimens total doses were converted to EQD_2,T. Only studies using an EQD_2,T of at least 49.5 Gy, which corresponds to the conventional 60 Gy in six weeks, were included. In a total of 3256 patients, the median OS was 17 months (range 7.4–30 months). While OS was better for patients treated after the year 2000 (P = 0.003) or with a mandatory ¹⁸F‐FDG‐PET‐CT in the diagnostic work‐up (P = 0.001), treatment sequence did not make a difference (P = 0.106). The most commonly reported toxicity was acute esophagitis (AE) with a median rate of 24% (range 0%–84%). AE increased at a rate of 0.5% per Gy increment in EQD_2,T (P = 0.016). Dose escalation above the conventional 60 Gy using modified radiation fractionation schedules and shortened OTT yield similar mOS and LRC regardless of treatment sequence with a significant EQD_2,T dependent increase in AE.

Key points

Significant findings

Modified radiation dose escalation sequentially combined with chemotherapy yields similar outcome as concomitant treatment.

OS is better with the mandatory inclusion of FDG‐PET‐CT in the diagnostic work‐up.

The risk of acute esophagitis increases with higher EQD_2,T.

What this study adds

Chemo‐radiotherapy (CRT) with modified dose escalation regimens yields OS and LC rates in the range of standard therapy regardless of treatment sequence. This broadens the database of curative options in patients who are not eligible concomitant CRT.

Toxicity and cosmetic outcome after hypofractionated whole breast irradiation and boost-IOERT in early stage breast cancer (HIOB): First results of a prospective multicenter trial (NCT01343459)

BACKGROUND AND PURPOSE

To assess the role of intraoperative radiation with electrons (IOERT) as tumor bed boost followed by hypofractionated whole breast irradiation (HWBI) after breast conserving surgery (BCS) of patients with low to intermediate risk breast cancer focusing on acute/late toxicity and cosmetic outcome.

MATERIAL AND METHODS

In 2011, a prospective multicenter trial (NCT01343459) was started. Treatment consisted of BCS, IOERT (11.1 Gy) and HWBI (40.5 Gy in 15 fractions). In a single-arm design, 5-year IBR-rates are benchmarked by a sequential ratio test (SQRT) against best published evidences in 3 age groups (35-40 y, 41-50 y, >50 y). Acute/late toxicity and cosmesis were evaluated by validated scorings systems.

RESULTS

Of 627 eligible patients, 44 were excluded, leaving 583 to analyze. After a median follow-up (FUP) of 45 months (range 0-74), for acute effects CTCAE-score 0/1 was noted in 91% (end of HWBI) and 92% (4 weeks later), respectively. Late toxicity Grading 0/1 (mean values, ranges) by LENT-SOMA criteria were observed in 92.7% (89-97.3) at 4/5 months, rising to 96.5% (91-100) at 6 years post HWBI. Baseline cosmesis after wound healing prior to HWBI was scored as excellent/good in 86% of cases by subjective (patient) and in 74% by objective (doctor) assessment with no impairment thereafter.

CONCLUSIONS

Acute and late treatment tolerance of a combined Boost-IOERT/HWBI regimen is excellent in short/mid-term assessment. Postoperative cosmetic appearance is not impaired after 3 years FUP.

Pulmonary function decreases moderately after accelerated high-dose irradiation for stage III non-small cell lung cancer

Background

Chemoradiotherapy (CRT) is the standard treatment for patients with inoperable stage III non‐small cell lung cancer (NSCLC) stage III. With a median OS beyond 30 months, adequate pulmonary function (PF) is essential to ensure acceptable quality of life after treatment. Forced expiratory volume in 1 second (FEV1) and diffusing capacity of the lung for carbon monoxide (DLCO) are the most widely used parameters to assess lung function. The aim of the current study was to evaluate dose‐volume effects of accelerated high‐dose radiation on PF.

Methods

A total of 72 patients were eligible for the current analysis. After induction chemotherapy, all patients received dose‐differentiated accelerated radiotherapy with intensity‐modulated radiotherapy (IMRT‐DART). PF tests were performed six weeks, three and six months after the end of radiotherapy.

Results

The median total dose to the tumor was 73.8 Gy (1.8 Gy bid) with a size dependent range between 61.2 and 90 Gy. In the whole cohort, 321 pulmonary function tests were performed. At six months, the median FEV1 relative to baseline was 0.95 (range: 0.56–1.36), and the relative median DLCO decreased to 0.98 (range: 0.64–1.50). The correlation between V20_{total lung} and FEV1 decline was statistically significant (P = 0.023). A total of 13 of 34 (38%) COPD patients had a 4%–21% FEV1 decrease.

Conclusion

Patients with a V20_{total lung} < 21% are at a low risk for PF decrease after high dose irradiation treatment. Although overall short term FEV1 and DLCO differ only moderately from baseline these changes may be clinically important, especially in patients with COPD.

Key points

Significant findings:

Pulmonary function after high dose irradiation decreases only moderately.

FEV1 and DLCO decrease depend on V20_{total lung}.

Small differences in lung function may be clinically important for COPD patients.

KPS predicts minimal clinically important differences (MCID).

What this study adds:

This study shows that high‐dose irradiation delivered with intensity‐modulated techniques does not impair short‐term lung function even in patients with compromised respiratory capacity before treatment. This is a pre‐requisite for adequate quality of life after thoraco‐oncological therapy.

Survival in early lung cancer patients treated with high dose radiotherapy is independent of pathological confirmation

BACKGROUND

Approximately 15% of lung cancer patients are diagnosed in early stages. Microscopic proof of disease cannot always be obtained because of comorbidity or reluctance to undergo invasive diagnostic procedures. In the current study, survival data of patients with and without pathology are compared.

METHODS

One hundred and sixty three patients with NSCLC I-IIb (T3 N0) treated between 2002 and 2016 were eligible: 123 (75%) had pathological confirmation of disease, whereas 40 (25%) did not. In accordance with international guidelines, both groups received radiotherapy. Comorbidity was assessed with the Charlson Comorbidity Index (CCI).

RESULTS

The median follow-up was 28.6 months (range: 0.3-162): 66 (40%) patients are still alive, while 97 (59%) patients died: 48 (29%) cancer-related deaths and 49 (30%) from causes other than cancer. Median overall survival (OS) in patients without pathological confirmation was 58.6 months (range: 0.5-162), which did not differ from those with microscopic proof of disease (39.4 months, range: 0.3-147.5; logrank P = 0.481). Median cancer-specific survival (CSS) also did not differ at 113.4 months (range: 0.5-162) in the non-confirmation group (logrank P = 0.763) versus 51.5 months (range: 3.7-129.5) in patients with pathology. In Cox regression, a CCI of ≥ 3 was associated with poor OS (hazard ratio 2.0; range 1.2-3.4; P = 0.010) and CSS (hazard ratio 2.0; 1.0-4.0; P = 0.043).

CONCLUSION

OS and CSS in early lung cancer patients depend on comorbidity rather than on pathological confirmation of disease.

Intraoperative Electron Radiotherapy (IOERT) in the Treatment of Primary Breast Cancer

IOERT (intraoperative electron radiotherapy) in breast cancer is used either as a boost (10-12 Gy) followed by whole breast irradiation (WBI) or as full-dose partial breast irradiation (PBI, 20-24 Gy) during breast-conserving surgery. IOERT has the longest evidence of all IORT techniques. When administered as a boost, excellent low local recurrence rates were observed in long-term follow-up >5 years. Even in high-risk groups like triple-negative or locally advanced breast cancers, IOERT contributes to long-term local control rates of more than 90%. For selected low-risk groups, IOERT as PBI with 21 Gy seems to be a viable treatment alternative to standard WBI. IOERT has been shown to be advantageous for several reasons: Geographic misses are avoided due to direct visualization of the tumor bed; thus, a high single dose is delivered with utmost precision to small volumes, completely sparing the skin and ensuring good long-term cosmetic outcome. Furthermore, high single doses seem to induce biological mechanisms with verifiable antitumor capability in in-vitro cell-line studies. In addition, IOERT markedly shortens the overall treatment time both in combination with (now mostly hypofractionated) WBI or as a PBI in selected low-risk constellations.

Intraoperative radiotherapy (IORT) as boost in breast cancer

The term IORT (intraoperative radiotherapy) is currently used for various techniques that show huge differences in dose delivery and coverage of the tissue at risk. The largest evidence for boost IORT preceding whole breast irradiation (WBI) originates from intraoperative electron treatments (IOERT) with single doses around 10 Gy. At median follow-up periods at 6 years, outstandingly low local recurrence rates of less than 1% are observed. Higher local relapse rates were described for G3 tumors and triple negative breast cancers as well as for IORT following primary systemic treatment for locally advanced tumors. Even there, long term (>5y) local tumor control rates mostly beyond 95% were maintained. Compared to other boost methods, an intraoperative treatment has evident advantages in terms of precision (by avoiding a “spatial and/or temporal miss”), cosmetic outcome and patient comfort. Direct visualisation of a tumor bed during surgery guarantees for an accurate dose delivery, which has additionally gained importance in times of primary reconstruction techniques after lumpectomy, since IORT is performed before breast tissue including parts of the tumor bed is mobilized for plastic purposes. As a consequence of direct tissue exposure without distension by hematoma/seroma, IORT allows for small treatment volumes and complete skin sparing, both having a positive effect on late tissue tolerance and, hence, cosmetic appearance. Boost IORT marginally prolongs the surgical procedure, while significantly shortening postoperative radiotherapy. Its combination with external beam radiotherapy to the whole breast (WBI) is currently tested in two multicentric prospective trials: as kV-IORT in the multicentric TARGIT-B (oost) study, and as IOERT in the HIOB trial (3 weeks hypofractionated WBI preceded by IORT electron boost).

Hsa-miR-375 is a predictor of local control in early stage breast cancer

Background

A long-term analysis by the Early Breast Cancer Trialist Group (EBCTG) revealed a strong correlation between local control and cancer-specific mortality. MicroRNAs (miRs), short (20–25 nucleotides) non-coding RNAs, have been described as prognosticators and predictors for breast cancer in recent years. The aim of the current study was to identify miRs that can predict local control after breast conserving therapy (BCT) in early stage breast cancer.

Results

Clinical data of 46 early stage breast cancer patients with local relapse after BCT were selected from the institutional database. These patients were matched to 101 control patients showing identical clinical features but without local relapse. The study was conducted in two steps. (1) In the pilot study, 32 patients (16 relapses versus 16 controls) were screened for the most de-regulated microRNAs (= candidate microRNAs) in a panel of 1250 miRs by microarray technology. Eight miRs were found to be significantly de-regulated. (2) In the validation study, the candidate microRNAs were analyzed in an independent cohort of 115 patients (30 relapses versus 85 controls) with reverse transcription quantitative polymerase chain reaction (RT-qPCR). From these eight candidates, hsa-miR-375 could be validated. Its median fold change was 2.28 (Mann-Whitney U test, corrected p value = 0.008). In the log-rank analysis, high expression levels of hsa-miR-375 correlated with a significantly higher risk of local relapse (p = 0.003). In a multivariate analysis (forward stepwise regression) including established predictors and prognosticators, hsa-miR-375 was the only variable that was able to distinguish the statistical significance between relapse and control groups (raw p value = 0.000195 HR = 0.76, 95 % CI 0.66–0.88; corrected p value = 0.005).

Conclusions

Hsa-miR-375 predicts local control in patient with early stage breast cancer, especially in estrogen receptor α (ER-α)-positive patients. It can therefore serve as an additional molecular marker for treatment choice independently from known predictors and prognosticators. Validation in larger prospective studies is warranted.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-016-0198-1) contains supplementary material, which is available to authorized users.

Survival and local control rates of triple-negative breast cancer patients treated with boost-IOERT during breast-conserving surgery

AIM

The purpose of this work was to retrospectively evaluate survival and local control rates of triple-negative breast cancer subtypes classified as five marker negative (5NP) and core basal (CB), respectively, after breast-conserving surgery and intraoperative boost radiotherapy with electrons (IOERT) followed by whole breast irradiation.

METHODS AND MATERIALS

A total of 71 patients with triple-negative breast cancer were enrolled, who were treated with lumpectomy, axillary lymph node dissection, and IOERT with 9.6 Gy (median Dmax) followed by normofractionated whole breast irradiation to median total doses of 54 Gy. Chemotherapy was applied in a neoadjuvant (12 %), adjuvant (75 %), or combinational setting (7 %).

RESULTS

After a median follow-up of 97 months (range 4-170 months), 5 in-breast recurrences were detected (7.0 %). For all patients, 8-year actuarial rates for local control, metastases-free survival, disease-specific survival, and overall survival amounted to 89, 75, 80, and 69 %, respectively. All local recurrences occurred in grade 3 (G3) tumors irrespective of their specific immunohistochemical phenotype; thus, the local control rate for grades 1/2 (G1/2) was 100 % for both 5NP and CB, while for G3 it was 88 % for 5NP and 90 % for CB (p = 0.65 and 0.82, respectively, n.s.). For disease-specific survival, only the difference of the best-prognosis group 5-NP/G3 vs. the worst-prognosis cohort CB/G1/2 was statistically significant: 90 % vs. 54 % (p = 0.03).

CONCLUSION

Boost-IOERT provides acceptable long-term in-breast control in triple negative breast cancer. The best subgroup in terms of disease-specific survival was represented by 5NP in combination with tumor grading G3.

Normal tissue complication models for clinically relevant acute esophagitis (≥ grade 2) in patients treated with dose differentiated accelerated radiotherapy (DART-bid)

Background

One of the primary dose-limiting toxicities during thoracic irradiation is acute esophagitis (AE). The aim of this study is to investigate dosimetric and clinical predictors for AE grade ≥ 2 in patients treated with accelerated radiotherapy for locally advanced non-small cell lung cancer (NSCLC).

Patients and methods

66 NSCLC patients were included in the present analysis: 4 stage II, 44 stage IIIA and 18 stage IIIB. All patients received induction chemotherapy followed by dose differentiated accelerated radiotherapy (DART-bid). Depending on size (mean of three perpendicular diameters) tumors were binned in four dose groups: <2.5 cm 73.8 Gy, 2.5–4.5 cm 79.2 Gy, 4.5–6 cm 84.6 Gy, >6 cm 90 Gy. Patients were treated in 3D target splitting technique. In order to estimate the normal tissue complication probability (NTCP), two Lyman models and the cutoff-logistic regression model were fitted to the data with AE ≥ grade 2 as statistical endpoint. Inter-model comparison was performed with the corrected Akaike information criterion (AIC_c), which calculates the model’s quality of fit (likelihood value) in relation to its complexity (i.e. number of variables in the model) corrected by the number of patients in the dataset. Toxicity was documented prospectively according to RTOG.

Results

The median follow up was 686 days (range 84–2921 days), 23/66 patients (35 %) experienced AE ≥ grade 2. The actuarial local control rates were 72.6 % and 59.4 % at 2 and 3 years, regional control was 91 % at both time points. The Lyman-MED model (D50 = 32.8 Gy, m = 0.48) and the cutoff dose model (D_c = 38 Gy) provide the most efficient fit to the current dataset. On multivariate analysis V38 (volume of the esophagus that receives 38 Gy or above, 95 %-CI 28.2–57.3) was the most significant predictor of AE ≥ grade 2 (HR = 1.05, CI 1.01–1.09, p = 0.007).

Conclusion

Following high-dose accelerated radiotherapy the rate of AE ≥ grade 2 is slightly lower than reported for concomitant radio-chemotherapy with the additional benefit of markedly increased loco-regional tumor control. In the current patient cohort the most significant predictor of AE was found to be V38. A second clinically useful parameter in treatment planning may be MED (mean esophageal dose).

Electronic supplementary material

The online version of this article (doi:10.1186/s13014-015-0429-1) contains supplementary material, which is available to authorized users.

IOERT as anticipated tumor bed boost during breast-conserving surgery after neoadjuvant chemotherapy in locally advanced breast cancer--results of a case series after 5-year follow-up

To evaluate retrospectively rates of local (LCR) and locoregional tumor control (LRCR) in patients with locally advanced breast cancer (LABC) who were treated with preoperative chemotherapy (primary systemic treatment, PST) followed by breast-conserving surgery (BCS) and either intraoperative radiotherapy with electrons (IOERT) preceding whole-breast irradiation (WBI) (Group 1) or with WBI followed by an external tumor bed boost (electrons or photons) instead of IOERT (Group 2). From 2002 to 2007, 83 patients with clinical Stage II or III breast cancer were enrolled in Group 1 and 26 in Group 2. All patients received PST followed by BCS and axillary lymph node dissection. IOERT boosts were applied by single doses of 9 Gy (90% reference isodose) versus external boosts of 12 Gy (median dose range, 6-16) in 2 Gy/fraction (ICRU). WBI in both groups was performed up to total doses of 51-57 Gy (1.7-1.8 Gy/fraction). The respective median follow-up times for Groups 1 and 2 amount 59 months (range, 3-115) and 67.5 months (range, 13-120). Corresponding 6-year rates for LCR, LRCR, metastasis-free survival, disease-specific survival and overall survival were 98.5, 97.2, 84.7, 89.2 and 86.4% for Group 1 and 88.1, 88.1, 74, 92 and 92% for Group 2, respectively, without any statistical significances. IOERT as boost modality during BCS in LABC after PST shows a trend to be superior in terms of LCR and LRCR in comparison with conventional boosts.

Partial breast re-irradiation for local recurrence of breast carcinoma: Benefit and long term side effects

INTRODUCTION AND AIMS

To evaluate the outcome after partial breast re-irradiation for in-breast tumor recurrence (IBTR) following second breast conserving surgery (BCS) as alternative to salvage mastectomy.

METHODS AND RESULTS

A survey of the literature was performed including publications between 2002 and 2012 (PubMed). Strategies comprised partial breast radiotherapy by external beam radiotherapy (EBRT), interstitial brachytherapy (BT) in low-, high- and pulse-dose rate technique, combined EBRT/BT, and intraoperative radiotherapy (IORT). Published evidence is scarce, with altogether ten articles identified, in sum reporting about 310 patients. The vast majority (82%) was treated by brachytherapy. Selection criteria for a second breast conservation attempt were comparable within all reports: all women presented with T0-2 recurrent lesions, late onset after primary treatment (70 months, mean of means) and no evidence of metastatic disease before undergoing gross tumor resection with free surgical margins. Treatment doses were in a similar range for brachytherapy (LDR 30-55 Gy, HDR 30-34 Gy; PDR 40-50 Gy), biologically comparable to the only series exclusively using EBRT (50 Gy). Follow-up times amounted 49 months (mean of the means, range 21-89). Oncologic results were similar among the different methods with local control rates ranging between 76% and 100%, and disease free and overall survival rates comparable to mastectomy series. Acute toxicity was low in all cohorts. All authors reported cosmetic outcome, scoring results from excellent to good in 60-80% of patients, mostly without using standardized evaluation schemes. Major late effects were fibrosis in re-irradiated parenchyma as a function of dose and volume, asymmetry (primarily due to double surgery), and breast pain. There were hardly any G3 and no G4 late reactions noted.

DISCUSSION AND CONCLUSION

In a highly selected group of patients with IBTR, partial breast irradiation after second BCS is a viable alternative to mastectomy, yielding high breast preservation rates without compromising oncologic safety. Whereas the evidence for brachytherapy is more solid, there is still little information about the effectiveness of PBI via EBRT or novel strategies like IORT, which therefore should preferably be investigated within trials.

Hypofractionated stereotactic radiotherapy of acoustic neuroma: volume changes and hearing results after 89-month median follow-up

PURPOSE

The goal of this work was to evaluate toxicity and local control following hypofractionated stereotactic radiation treatment with special focus on changes in tumor volume and hearing capacity.

PATIENTS AND METHODS

In all, 29 patients with unilateral acoustic neuroma were treated between 2001 and 2007 within a prospective radiation protocol (7 × 4 Gy ICRU dose). Median tumor volume was 0.9 ml. Follow-up started at 6 months and was repeated annually with MRI volumetry and audiometry. Hearing preservation was defined as preservation of Class A/B hearing according to the guidelines of the American Academy of Otolaryngology (1995).

RESULTS

No patient had any intervention after a median imaging follow-up of 89.5 months, one patient showed radiological progression. Transient increase of tumor volume developed in 17/29 patients, whereas 22/29 patients (75.9%) presented with a volume reduction at last follow-up. A total of 21 patients were eligible for hearing evaluation. Mean pure tone average (PTA) deteriorated from 39.3 to 65.9 dB and mean speech discrimination score (SDS) dropped from 74.3 to 38.1%. The 5-year actuarial Class A/B hearing preservation rate was 50.0 ± 14.4%.

CONCLUSION

Radiation increases only minimally, if at all, the hearing deterioration which emerges by observation alone. Presbyacusis is not responsible for this deterioration. Transient tumor enlargement is common. Today radiation of small- and medium-sized acoustic neuroma can be performed with different highly conformal techniques as fractionated treatment or single low-dose radiosurgery with equal results regarding tumor control, hearing preservation, and side effects. Hypofractionation is more comfortable for the patient than conventional regimens and represents a serious alternative to frameless radiosurgery.

DART-bid (Dose-differentiated accelerated radiation therapy, 1.8 Gy twice daily)--a novel approach for non-resected NSCLC: final results of a prospective study, correlating radiation dose to tumor volume

Background

Sequential chemo-radiotherapies with intensive radiation components deliver promising results in non-resected non-small cell lung cancer (NSCLC). In general, radiation doses are determined by dose constraints for normal tissues, not by features relevant for tumor control. DART-bid targets directly the doses required for tumor control, correlating doses to tumor volume in a differentiated mode.

Materials/Methods

Radiation doses to primary tumors were aligned along increasing tumor size within 4 groups (<2.5 cm/2.5–4.5 cm/4.5–6.0 cm/>6.0 cm; mean number of three perpendicular diameters). ICRU-doses of 73.8 Gy/79.2 Gy/84.6 Gy/90.0 Gy, respectively, were applied. Macroscopically involved nodes were treated with a median dose of 59.4 Gy, nodal sites about 6 cm cranial to involved nodes electively with 45 Gy. Fractional doses were 1.8 Gy twice daily (bid).

2 cycles chemotherapy were given before radiotherapy.

Between 2004 and 2009, 160 not selected patients with 164 histologically/cytologically proven NSCLC were enrolled; Stage I: 38 patients; II: 6 pts.; IIIA: 69 pts.; IIIB: 47 pts. Weight loss >5%/3 months: 38 patients (24%).

Primary endpoints are local and regional tumor control rates at 2 years (as >90% of locoregional failures occur within 2 years). Secondary endpoints are survival and toxicity. With a minimum follow-up time of 2 years for patients alive, the final results are presented.

Results

32 local and 10 regional recurrences occurred. The local and regional tumor control rates at 2 years are 77% and 93%, respectively.

The median overall survival (OS) time is 28.0 months, the 2- and 5-year OS rates are 57% and 19%, respectively. For stage III patients, median OS amounts to 24.3 months, 2- /5-year OS rates to 51% and 18%, respectively.

2 treatment-related deaths (progressive pulmonary fibrosis) occurred in patients with pre-existing pulmonary fibrosis. Further acute and late toxicity was mild.

Conclusions

This novel approach yields a high level of locoregional tumor control and survival times. In general it is well tolerated. In all outcome parameters it seems to compare favourably with simultaneous chemo-radiotherapies, at present considered ‘state of the art’; and is additionally amenable for an unselected patient population.

Prospective evaluation of quality of life effects in patients undergoing palliative radiotherapy for brain metastases

Background

Recently published results of quality of life (QoL) studies indicated different outcomes of palliative radiotherapy for brain metastases. This prospective multi-center QoL study of patients with brain metastases was designed to investigate which QoL domains improve or worsen after palliative radiotherapy and which might provide prognostic information.

Methods

From 01/2007-01/2009, n=151 patients with previously untreated brain metastases were recruited at 14 centers in Germany and Austria. Most patients (82 %) received whole-brain radiotherapy. QoL was measured with the EORTC-QLQ-C15-PAL and brain module BN20 before the start of radiotherapy and after 3 months.

Results

At 3 months, 88/142 (62 %) survived. Nine patients were not able to be followed up. 62 patients (70.5 % of 3-month survivors) completed the second set of questionnaires. Three months after the start of radiotherapy QoL deteriorated significantly in the areas of global QoL, physical function, fatigue, nausea, pain, appetite loss, hair loss, drowsiness, motor dysfunction, communication deficit and weakness of legs. Although the use of corticosteroid at 3 months could be reduced compared to pre-treatment (63 % vs. 37 %), the score for headaches remained stable. Initial QoL at the start of treatment was better in those alive than in those deceased at 3 months, significantly for physical function, motor dysfunction and the symptom scales fatigue, pain, appetite loss and weakness of legs. In a multivariate model, lower Karnofsky performance score, higher age and higher pain ratings before radiotherapy were prognostic of 3-month survival.

Conclusions

Moderate deterioration in several QoL domains was predominantly observed three months after start of palliative radiotherapy for brain metastases. Future studies will need to address the individual subjective benefit or burden from such treatment. Baseline QoL scores before palliative radiotherapy for brain metastases may contain prognostic information.

Treatment strategies for oesophageal cancer - time-trends and long term outcome data from a large tertiary referral centre

Background and objectives

Treatment options for oesophageal cancer have changed considerably over the last decades with the introduction of multimodal treatment concepts dominating the progress in the field. However, it remains unclear in how far the documented scientific progress influenced and changed the daily routine practice. Since most patients with oesophageal cancer generally suffer from reduced overall health conditions it is uncertain how high the proportion of aggressive treatments is and whether outcomes are improved substantially. In order to gain insight into this we performed a retrospective analysis of patients treated at a larger tertiary referral centre over time course of 25 years.

Patients and methods

Data of all patients diagnosed with squamous cell carcinoma (SCC) and adenocarcinoma (AC) of the oesophagus, treated between 1983 and 2007 in the department of radiation oncology of the LMU, were obtained. The primary endpoint of the data collection was overall survival (calculated from the date of diagnosis until death or last follow up). Changes in basic clinical characteristics, treatment approach and the effect on survival were analysed after dividing the cohort into five subsequent time periods (I-V) with 5 years each. In a second analysis any pattern of change regarding the use of radio(chemo)therapy (R(C)T) with and without surgery was determined.

Results

In total, 503 patients with SCC (78.5%) and AC (18.9%) of the oesophagus were identified. The average age was 60 years (range 35-91 years). 56.5% of the patients were diagnose with advanced UICC stages III-IV. R(C)T was applied to 353 (70.2%) patients; R(C)T+ surgery was performed in 134 (26.6%) patients, 63.8% of all received chemotherapy (platinum-based 5.8%, 5-fluorouracil (5-FU)12.1%, 42.3% 5-FU and mitomycin C (MMC)). The median follow-up period was 4.3 years. The median overall survival was 21.4 months. Over the time, patients were older, the formal tumour stage was more advanced, the incidence of AC was higher and the intensified treatment had a higher prevalence. However there was only a trend for an improved OS over the years with no difference between RCT with or without surgery (p = 0.09). The use of radiation doses over 54 Gy and the addition of chemotherapy (p = 0.002) were associated with improved OS.

Conclusion

Although more complex treatment protocols were introduced into clinical routine, only a minor progress in OS rates was detectable. Main predictors of outcome in this cohort was the addition of chemotherapy. The addition of surgery to radio-chemotherapy may only be of value for very limited patient groups.

MiRNA expression patterns predict survival in glioblastoma

Background

In order to define new prognostic subgroups in patients with glioblastoma a miRNA screen (> 1000 miRNAs) from paraffin tissues followed by a bio-mathematical analysis was performed.

Methods

35 glioblastoma patients treated between 7/2005 - 8/2008 at a single institution with surgery and postoperative radio(chemo)therapy were included in this retrospective analysis. For microarray analysis the febit biochip "Geniom^® Biochip MPEA homo-sapiens" was used. Total RNA was isolated from FFPE tissue sections and 1100 different miRNAs were analyzed.

Results

It was possible to define a distinct miRNA expression pattern allowing for a separation of distinct prognostic subgroups. The defined miRNA pattern was significantly associated with early death versus long-term survival (split at 450 days) (p = 0.01). The pattern and the prognostic power were both independent of the MGMT status.

Conclusions

At present, this is the first dataset defining a prognostic role of miRNA expression patterns in patients with glioblastoma. Having defined such a pattern, a prospective validation of this observation is required.

Curative treatment of oesophageal carcinoma: current options and future developments

Since the 1980s major advances in surgery, radiotherapy and chemotherapy have established multimodal approaches as curative treatment options for oesophageal cancer. In addition the introduction of functional imaging modalities such as PET-CT created new opportunities for a more adequate patient selection and therapy response assessment.

The majority of oesophageal carcinomas are represented by two histologies: squamous cell carcinoma and adenocarcinoma. In recent years an epidemiological shift towards the latter was observed. From a surgical point of view, adenocarcinomas, which are usually located in the distal third of the oesophagus, may be treated with a transhiatal resection, whereas squamous cell carcinomas, which are typically found in the middle and the upper third, require a transthoracic approach. Since overall survival after surgery alone is poor, multimodality approaches have been developed. At least for patients with locally advanced tumors, surgery alone can no longer be advocated as routine treatment. Nowadays, scientific interest is focused on tumor response to induction radiochemotherapy. A neoadjuvant approach includes the early and accurate assessment of clinical response, optimally performed by repeated PET-CT imaging and endoscopic ultrasound, which may permit early adaption of the therapeutic concept. Patients with SCC that show clinical response by PET CT are considered to have a better prognosis, regardless of whether surgery will be performed or not. In non-responding patients salvage surgery improves survival, especially if complete resection is achieved.

MicroRNA expression profiles in human cancer cells after ionizing radiation

INTRODUCTION

MicroRNAs are regulators of central cellular processes and are implicated in the pathogenesis and prognosis of human cancers. MicroRNAs also modulate responses to anti-cancer therapy. In the context of radiation oncology microRNAs were found to modulate cell death and proliferation after irradiation. However, changes in microRNA expression profiles in response to irradiation have not been comprehensively analyzed so far. The present study's intend is to present a broad screen of changes in microRNA expression following irradiation of different malignant cell lines.

MATERIALS AND METHODS

1100 microRNAs (Sanger miRBase release version 14.0) were analyzed in six malignant cell lines following irradiation with clinically relevant doses of 2.0 Gy. MicroRNA levels 6 hours after irradiation were compared to microRNA levels in non-irradiated cells using the "Geniom Biochip MPEA homo sapiens".

RESULTS

Hierarchical clustering analysis revealed a pattern, which significantly (p = 0.014) discerned irradiated from non-irradiated cells. The expression levels of a number of microRNAs known to be involved in the regulation of cellular processes like apoptosis, proliferation, invasion, local immune response and radioresistance (e. g. miR-1285, miR-24-1, miR-151-5p, let-7i) displayed 2 - 3-fold changes after irradiation. Moreover, several microRNAs previously not known to be radiation-responsive were discovered.

CONCLUSION

Ionizing radiation induced significant changes in microRNA expression profiles in 3 glioma and 3 squamous cell carcinoma cell lines. The functional relevance of these changes is not addressed but should by analyzed by future work especially focusing on clinically relevant endpoints like radiation induced cell death, proliferation, migration and metastasis.

Long-term outcome of mitomycin C- and 5-FU-based primary radiochemotherapy for esophageal cancer

BACKGROUND AND PURPOSE

For definitive radiochemotherapy, 5-fluorouracil/cisplatin protocols have been considered the standard of care for esophageal carcinoma over the last 2 decades. By contrast, most patients treated at the University Hospital, LMU Munich, Germany, received 5-fluorouracil/mitomycin C. The objective of this retrospective analysis was to determine the value of 5-fluorouracil/mitomycin-C-based therapy.

PATIENTS AND METHODS

Tumor stage, treatment received, and outcome data of patients treated for esophageal cancer between 1982 and 2007 were collected; endpoint of the analysis was overall survival.

RESULTS

298 patients with inoperable cancer of the esophagus were identified (16.8% adenocarcinoma, 77.5% squamous cell carcinoma). At diagnosis, 61.7% (184/298) had UICC stage III-IV, 54.4% (162/298) positive lymph nodes, and 26.5% (79/298) metastatic disease. 74.5% of all patients (222/298) received radiation doses between 55 and 65 Gy, 65.8% (196/298) were subjected to concomitant chemotherapy. The median follow-up period (patients alive) was 4.1 years. A significant increase of overall survival (p < 0.0001) in the radiochemotherapy versus the radiotherapy-alone group was observed. 52% (102/196) in the 5-fluorouracil/ mitomycin C group had tumor stages comparable to the RTOG 85-01 study cohort (T1-3 N0-1 M0). The median survival in this subgroup was 18.2 months, 3- and 5-year survival rates were 22.7% (21/102) and 15.0% (13/102), respectively.

CONCLUSION

Despite being nominally inferior to platinum-based radiochemotherapy, the overall survival rates are in a similar range. Thus, the mitomycin-C-based radiochemotherapy approach may considered to be as effective as the standard therapy. However, there is no randomized trial available in order to prove the equality.

Neoadjuvant chemoradiation therapy with capecitabine (X) plus cetuximab (C), and external beam radiotherapy (RT) in locally advanced rectal cancer (LARC): ABCSG trial R03

4109

Background: Pre-operative chemoradiation is a standard treatment for LARC. X and C are synergistic with radiotherapy and active in colorectal neoplasms. This phase II multicenter trial was designed to assess the feasability and tolerability of a preoperative combination of X, C, plus RT in patients with LARC. Secondary endpoints were downstaging-rate and induction of complete pathological response (CPR). Only patients (pts.) with MRT-documented T3/T4-tumours were included. Methods: Pts. with potentially resectable cT4 or cT3 LARC (lower/mid rectum) were enrolled. Chemoradiotherapy consisted of X (825mg/sqm twice daily on RT-days weeks 1–4), C (400mg/sqm loading dose once per week, 200mg/sqm weekly x 4) and pelvic RT 3D conformation technique (1.8Gy/day, 45Gy total). Surgery was performed 28–42 days after completion of RT. Results: 31 pts. were enrolled, median age was 61 years (range 41 to 80), PS 0: 22 pts. (71%), PS 1: 8 pts. (26%), PS 2: 1 pt. (3%). 21 pts. (68%) presented with cT4, 10 pts. (32%) with cT3 tumors. 25 pts. (81%) had positive lymph nodes (LN) by imaging, 2 pts. were LN-negative, 4 pts. (13%) are not evaluable for N-stage. 28 pts (90%) are available for evaluation of toxicity and efficacy. Treatment with X and C plus RT was well tolerated, in only 4 pts. grade 3 toxicity was observed: acneiform skin rash 2 pts (7%), diarrhea 3 pts (11%), 1 pt. (4%) suffered from grade 4 diarrhea. Median dose intensity of X and C was >95% during the entire treatment period. Tumor downstaging was observed in 14 pts. (50%) total, 12/19 (63%) T4 tumours and 2/9 (22%) T3 tumors responded. While no patient achieved a CPR, in 14 pts. a lymph node clearing (ypN0) was observed. Conclusions: The combination of capecitabine and cetuximab plus radiotherapy is a well tolerated preoperative treatment regime for LARC (cT3/4). The main toxicity consisted of diarrhea. The combination is effective in the primary tumor as well as in the lymph nodes, both with possible impact on therapy outcome.

No significant financial relationships to disclose.

Job stress and job satisfaction of physicians, radiographers, nurses and physicists working in radiotherapy: a multicenter analysis by the DEGRO Quality of Life Work Group

BACKGROUND

Ongoing changes in cancer care cause an increase in the complexity of cases which is characterized by modern treatment techniques and a higher demand for patient information about the underlying disease and therapeutic options. At the same time, the restructuring of health services and reduced funding have led to the downsizing of hospital care services. These trends strongly influence the workplace environment and are a potential source of stress and burnout among professionals working in radiotherapy.

METHODS AND PATIENTS

A postal survey was sent to members of the workgroup "Quality of Life" which is part of DEGRO (German Society for Radiooncology). Thus far, 11 departments have answered the survey. 406 (76.1%) out of 534 cancer care workers (23% physicians, 35% radiographers, 31% nurses, 11% physicists) from 8 university hospitals and 3 general hospitals completed the FBAS form (Stress Questionnaire of Physicians and Nurses; 42 items, 7 scales), and a self-designed questionnaire regarding work situation and one question on global job satisfaction. Furthermore, the participants could make voluntary suggestions about how to improve their situation.

RESULTS

Nurses and physicians showed the highest level of job stress (total score 2.2 and 2.1). The greatest source of job stress (physicians, nurses and radiographers) stemmed from structural conditions (e.g. underpayment, ringing of the telephone) a "stress by compassion" (e.g. "long suffering of patients", "patients will be kept alive using all available resources against the conviction of staff"). In multivariate analyses professional group (p < 0.001), working night shifts (p = 0.001), age group (p = 0.012) and free time compensation (p = 0.024) gained significance for total FBAS score. Global job satisfaction was 4.1 on a 9-point scale (from 1 - very satisfied to 9 - not satisfied). Comparing the total stress scores of the hospitals and job groups we found significant differences in nurses (p = 0.005) and physicists (p = 0.042) and a borderline significance in physicians (p = 0.052).In multivariate analyses "professional group" (p = 0.006) and "vocational experience" (p = 0.036) were associated with job satisfaction (cancer care workers with < 2 years of vocational experience having a higher global job satisfaction). The total FBAS score correlated with job satisfaction (Spearman-Rho = 0.40; p < 0.001).

CONCLUSION

Current workplace environments have a negative impact on stress levels and the satisfaction of radiotherapy staff. Identification and removal of the above-mentioned critical points requires various changes which should lead to the reduction of stress.

"Augmented reality" in conventional simulation by projection of 3-D structures into 2-D images: a comparison with virtual methods

BACKGROUND AND PURPOSE

In this study, a new method is introduced, which allows the overlay of three-dimensional structures, that have been delineated on transverse slices, onto the fluoroscopy from conventional simulators in real time.

PATIENTS AND METHODS

Setup deviations between volumetric imaging and simulation were visualized, measured and corrected for 701 patient isocenters.

RESULTS

Comparing the accuracy to mere virtual simulation lacking additional X-ray imaging, a clear benefit of the new method could be shown. On average, virtual prostate simulations had to be corrected by 0.48 cm (standard deviation [SD] 0.38), and those of the breast by 0.67 cm (SD 0.66).

CONCLUSION

The presented method provides an easy way to determine entity-specific safety margins related to patient setup errors upon registration of bony anatomy (prostate 0.9 cm for 90% of cases, breast 1.3 cm). The important role of planar X-ray imaging was clearly demonstrated. The innovation can also be applied to adaptive image-guided radiotherapy (IGRT) protocols.