S. Adeberg

Histology of non-small cell lung cancer predicts the response to stereotactic body radiotherapy

BACKGROUND AND PURPOSEnTo investigate the prognostic impact of different histological subtypes of non-small cell lung cancer (NSCLC) on outcome following stereotactic body radiotherapy (SBRT) for NSCLC patients.nnnMATERIALS AND METHODSnWe analyzed 126 consecutive patients with early-stage adenocarcinoma or squamous cell carcinoma treated with SBRT from 2004 to 2016. Adenocarcinoma patients were further sub-classified as high-risk or low-risk tumors.nnnRESULTSnWith a median follow-up time of 22months, 2-year overall survival (OS), local (LC), and distant control (DC) were 68%, 90% and 79%, respectively. For LC, histologic subtype was identified as major independent prognostic factor (p=0.033): while LC was 81% for squamous cell carcinoma patients, LC was significantly improved for high-risk and even more non-high-risk adenocarcinoma patients with 96% and 100%, respectively (p=0.026). The negative prognostic impact of the histologic subtype squamous cell carcinoma was not evident when patients received SBRT with higher total doses in EQD2 (2Gy equivalent dose): if patients were treated with a total dose in EQD2≥150Gy, no significant difference in LC for histologic subtypes was detected anymore (p=0.355).nnnCONCLUSIONnIn the current study, histologic subtypes of NSCLC predicted local control probabilities following SBRT. Prospective, multi-center studies are needed to evaluate the prognostic impact of histology and consecutively the need for SBRT dose adaptation.

Impact of 18F-FET PET on Target Volume Definition and Tumor Progression of Recurrent High Grade Glioma Treated with Carbon-Ion Radiotherapy

High-precision radiotherapy (HPR) of recurrent high grade glioma (HGG) requires accurate spatial allocation of these infiltrative tumors. We investigated the impact of 18F-FET PET on tumor delineation and progression of recurrent HGG after HPR with carbon ions. T1 contrast enhanced MRI and 18F-FET-PET scans of 26 HGG patients were fused with radiotherapy planning volumes. PET-positive (PET+) tumor volumes using different isocontours (I%) were systematically investigated and compared with MRI-derived gross tumor volumes (GTV). Standardized uptake ratios (SUR) were further correlated with GTV and tumor progression patterns. In grade IV glioma, SURu2009>u20092.92 significantly correlated with poor median overall survival (6.5 vs 13.1 months, pu2009=u20090.00016). We found no reliable SUR cut-off criteria for definition of PET+ volumes. Overall conformity between PET and MRI-based contours was low, with maximum conformities between 0.42–0.51 at I40%. The maximum sensitivity and specificity for PET+ volumes outside of GTV predicting tumor progression were 0.16 (I40%) and 0.52 (I50%), respectively. In 75% of cases, FLAIR hyperintense area covered over 80% of PET+ volumes. 18F-FET-PET derived SUR has a prognostic impact in grade IV glioma. The value of substantial mismatches between MRI-based GTV and PET+ volumes to improve tumor delineation in radiotherapy awaits further validation in randomized prospective trials.

Establishing stereotactic body radiotherapy with flattening filter free techniques in the treatment of pulmonary lesions - initial experiences from a single institution

BackgroundStereotactic body radiotherapy (SBRT) using flattening filter free (FFF)-techniques has been increasingly applied during the last years. However, clinical studies investigating this emerging technique are still rare. Hence, we analyzed toxicity and clinical outcome of pulmonary SBRT with FFF-techniques and performed dosimetric comparison to conventional techniques using flattening filters (FF).Materials and methodsBetween 05/2014 and 06/2015, 56 consecutive patients with 61 pulmonary lesions were treated with SBRT in FFF-mode. Central lesions received 8u2009×u20097.5xa0Gy delivered to the conformally enclosing 80xa0%-isodose, while peripheral lesions were treated with 3u2009×u200915xa0Gy, prescribed to the 65xa0%-isodose. Early and late toxicity (after 6xa0months) as well as initial clinical outcomes were evaluated. Furthermore, [deleted] plan quality and efficiency were evaluated by analyzing conformity, beam- on and total treatment delivery times in comparison to plans with FF-dose application.ResultsMedian follow-up time was 9.3xa0months (range 1.5–18.0xa0months). Early toxicity was low with only 5 patients (8.9xa0%) reporting CTCAE 2° or higher side-effects. Only one patient (1.8xa0%) was diagnosed with radiation-induced pneumonitis CTCAE 3°, while 2 (3.6xa0%) patients suffered from pneumonitis CTCAE 2°. After 6xa0months, no toxicity greater than CTCAE 2° was reported. 1-year local progression-free survival, distant progression-free survival and overall survival were 92.8xa0%, 78.0xa0%, and 94.4xa0%, respectively. While plan quality was similar for FFF- and FF-plans in respect to conformity (pu2009=u20090.275), median beam-on time as well as total treatment time were significantly reduced for SBRT in FFF-mode compared to FF-mode (pu2009≤u20090.001, pu2009≤u20090.001).ConclusionsPatient treatment with SBRT using FFF-techniques is safe and provides promising clinical results with only modest toxicity at significantly increased dose delivery speed.

Lymphadenectomy in women with endometrial cancer: aspiration and reality from a radiation oncologist's point of view

BackgroundTo investigate the meaning of lymphadenectomy (LNE) in women with endometrial cancer (EC) for clinical outcome and secondly to determine the impact of the method of adjuvant radiotherapy (RT) on survival as well as to define prognostic factors.Methods322 patients (pts) underwent adjuvant RT for endometrioid EC at our department from 2004 until 2012 and were included in this retrospective study. Chi-square test, LogRank test and Cox regression were used for statistical analyses.ResultsMedian age at diagnosis: 66xa0years. FIGO stages: FIGO I 69.4xa0%, FIGO II 15.3xa0%, FIGO III 14.5xa0%, FIGO IV 0.9xa0%. Surgical staging: 30.6xa0% pelvic/paraaortic LNE, 45xa0% sole pelvic LNE, 8.8xa0% sampling of suspicious lymph nodes, 15.6xa0% no LNE. Adjuvant chemotherapy (ChT): 3.2xa0%. Sole intravaginal brachytherapy (IVB): 60.2xa0%. IVBu2009+u2009external beam radiotherapy (EBRT): 39.8xa0%. 5-year local recurrence free survival (LRFS): 90.6xa0%, distant metastases free survival (DMFS): 89.8xa0%, overall survival (OS):79.3xa0%. In multivariate analysis age (pu2009=u2009.007), pT stage (pu2009=u2009.029), lymph node status (pu2009=u2009.003), grading (pu2009=u2009.011) and lymphovascular space invasion (LVSI; pu2009=u2009.008) remained as independent prognostic factors for OS. Resection status (pu2009=u2009.01) and LVSI (pu2009=u2009.014) were independent prognostic factors for LRFS and LVSI (pu2009=u2009.008) was the only independent prognostic factor for DMFS. There was no statistically significant survival benefit from LNE in LRFS (pu2009=u2009.561), DMFS (pu2009=u2009.981) or OS (pu2009=u2009.791). 5-year LRFS in stage I and II: 96.0 and 82.9xa0% after sole IVB, 90.8 and 81.6xa0% after combined IVB/EBRT (pu2009=u2009.105; pu2009=u2009.970). 5-year OS rates for stage I and II: 86.5 and 71.3xa0% after sole IVB, 84.2 % and 69.2xa0% after combined IVB/EBRT (pu2009=u2009.153; pu2009=u2009.619).ConclusionComprehensive surgical staging is rarely performed and may be omitted in women with endometrioid EC in stages I-II. Sole IVB delivers equally good local control as combined IVB/EBRT in pts with FIGO stage I and II disease. LVSI deserves more attention as a prognostic factor and these pts may require a combined local and systemic therapy.

Parenchymal and Functional Lung Changes after Stereotactic Body Radiotherapy for Early-Stage Non-Small Cell Lung Cancer—Experiences from a Single Institution

Introduction This study aimed to evaluate parenchymal and functional lung changes following stereotactic body radiotherapy (SBRT) for early-stage non-small cell lung cancer (NSCLC) patients and to correlate radiological and functional findings with patient and treatment characteristics as well as survival. Materials and methods Seventy patients with early-stage NSCLC treated with SBRT from 2004 to 2015 with more than 1u2009year of CT follow-up scans were analyzed. Incidence, morphology, severity of acute and late lung abnormalities as well as pulmonary function changes were evaluated and correlated with outcome. Results Median follow-up time was 32.2u2009months with 2-year overall survival (OS) of 83% and local progression-free survival of 88%, respectively. Regarding parenchymal changes, most patients only developed mild to moderate CT abnormalities. Mean ipsilateral lung dose (MLD) in biological effective dose and planning target volume size were significantly associated with maximum severity score of parenchymal changes (pu2009=u20090.014, pu2009<u20090.001). Furthermore, both maximum severity score and MLD were significantly connected with OS in univariate analysis (pu2009=u20090.043, pu2009=u20090.025). For functional lung changes, we detected significantly reduced total lung capacity, forced expiratory volume in 1u2009s, and forced vital capacity (FVC) parameters after SBRT (pu2009≤u20090.001). Multivariate analyses revealed SBRT with an MLDu2009≥u20099.72u2009Gy and FVC reduction ≥0.54u2009L as independent prognostic factors for inferior OS (pu2009=u20090.029, pu2009=u20090.004). Conclusion SBRT was generally tolerated well with only mild toxicity. For evaluating the possible prognostic impact of MLD and FVC reduction on survival detected in this analysis, larger prospective studies are truly needed.