Targeted Natural Killer Cell-Based Adoptive Immunotherapy for the Treatment of Patients with NSCLC after Radiochemotherapy: A Randomized Phase II Clinical Trial.

PURPOSE: Non-small cell lung cancer (NSCLC) is a fatal disease with poor prognosis. A membrane-bound form of Hsp70 (mHsp70) which is selectively expressed on high-risk tumors serves as a target for mHsp70-targeting natural killer (NK) cells. Patients with advanced mHsp70-positive NSCLC may therefore benefit from a therapeutic intervention involving mHsp70-targeting NK cells. The randomized phase II clinical trial (EudraCT2008-002130-30) explores tolerability and efficacy of ex vivo-activated NK cells in patients with NSCLC after radiochemotherapy (RCT). PATIENTS AND METHODS: Patients with unresectable, mHsp70-positive NSCLC (stage IIIa/b) received 4 cycles of autologous NK cells activated ex vivo with TKD/IL2 [interventional arm (INT)] after RCT (60-70 Gy, platinum-based chemotherapy) or RCT alone [control arm (CTRL)]. The primary objective was progression-free survival (PFS), and secondary objectives were the assessment of quality of life (QoL, QLQ-LC13), toxicity, and immunobiological responses. RESULTS: The NK-cell therapy after RCT was well tolerated, and no differences in QoL parameters between the two study arms were detected. Estimated 1-year probabilities for PFS were 67% [95% confidence interval (CI), 19%-90%] for the INT arm and 33% (95% CI, 5%-68%) for the CTRL arm (P = 0.36, 1-sided log-rank test). Clinical responses in the INT group were associated with an increase in the prevalence of activated NK cells in their peripheral blood. CONCLUSIONS: Ex vivo TKD/IL2-activated, autologous NK cells are well tolerated and deliver positive clinical responses in patients with advanced NSCLC after RCT.

Definitive, intensity modulated tomotherapy with a simultaneous integrated boost for prostate cancer patients - Long term data on toxicity and biochemical control.

AIM: To report long-term data regarding biochemical control and late toxicity of simultaneous integrated boost intensity modulated radiotherapy (SIB-IMRT) with tomotherapy in patients with localized prostate cancer. BACKGROUND: Dose escalation improves cancer control after curative intended radiation therapy (RT) to patients with localized prostate cancer, without increasing toxicity, if IMRT is used. MATERIALS AND METHODS: In this retrospective analysis, we evaluated long-term toxicity and biochemical control of the first 40 patients with intermediate risk prostate cancer receiving SIB-IMRT. Primary target volume (PTV) 1 including the prostate and proximal third of the seminal vesicles with safety margins was treated with 70 Gy in 35 fractions. PTV 2 containing the prostate with smaller safety margins was treated as SIB to a total dose of 76 Gy with 2.17 Gy per fraction. Toxicity was evaluated using an adapted CTCAE-Score (Version 3). RESULTS: Median follow-up of living patients was 66 (20-78) months. No late genitourinary toxicity higher than grade 2 has been reported. Grade 2 genitourinary toxicity rates decreased from 58% at the end of the treatment to 10% at 60 months. Late gastrointestinal (GI) toxicity was also moderate, though the prescribed PTV Dose of 76 Gy was accepted at the anterior rectal wall. 74% of patients reported any GI toxicity during follow up and no toxicity rates higher than grade 2 were observed. Grade 2 side effects were reported by 13% of the patients at 60 months. 5-year freedom from biochemical failure was 95% at our last follow up. CONCLUSION: SIB-IMRT using daily MV-CT guidance showed excellent long-term biochemical control and low toxicity rates.

Clinical outcome after high-precision radiotherapy for skull base meningiomas: Pooled data from three large German centers for radiation oncology.

PURPOSE: To evaluate outcome in patients with base of skull meningiomas treated with modern high precision radiation therapy (RT) techniques. PATIENTS AND METHODS: 927 patients from three centers were treated with either radiosurgery or fractionated high-precision RT for meningiomas. Treatment planning was based on CT and MRI following institutional guidelines. For radiosurgery, a median dose of 13 Gy was applied, for fractionated treatments, a median dose of 54 Gy in 1.8 Gy single fractions was prescribed. Follow-up included a clinical examination as well as contrast-enhanced imaging. All patients were followed up prospectively after radiotherapy in the three departments within a strict follow-up regimen. The median follow-up time was 81 months (range 1-348 months). RESULTS: Median local control was 79 months (range 1-348 months). Local control (LC) was 98% at 1 year, 94% at 3 years, 92% at 5 years and 86% at 10 years. There was no difference between radiosurgery and fractionated RT. We analyzed the influence of higher doses on LC and could show that dose did not impact LC. Moreover, there was no difference between 54 Gy and 57.6 Gy in the fractionated group. Side effects were below 5% in both groups without any severe treatment-related complications. DISCUSSION: Based on the pooled data analysis this manuscript provides a large series of meningiomas of the skull base treated with modern high precision RT demonstrating excellent local control and low rates of side effects. Such data support the recommendation of RT for skull base meningiomas in the interdisciplinary tumor board discussions. The strong role of RT must influence treatment recommendations keeping in mind the individual risk-benefit profile of treatment alternatives.

Increased cell survival and cytogenetic integrity by spatial dose redistribution at a compact synchrotron X-ray source.

X-ray microbeam radiotherapy can potentially widen the therapeutic window due to a geometrical redistribution of the dose. However, high requirements on photon flux, beam collimation, and system stability restrict its application mainly to large-scale, cost-intensive synchrotron facilities. With a unique laser-based Compact Light Source using inverse Compton scattering, we investigated the translation of this promising radiotherapy technique to a machine of future clinical relevance. We performed in vitro colony-forming assays and chromosome aberration tests in normal tissue cells after microbeam irradiation compared to homogeneous irradiation at the same mean dose using 25 keV X-rays. The microplanar pattern was achieved with a tungsten slit array of 50 µm slit size and a spacing of 350 µm. Applying microbeams significantly increased cell survival for a mean dose above 2 Gy, which indicates fewer normal tissue complications. The observation of significantly less chromosome aberrations suggests a lower risk of second cancer development. Our findings provide valuable insight into the mechanisms of microbeam radiotherapy and prove its applicability at a compact synchrotron, which contributes to its future clinical translation.

Tangential Field Radiotherapy for Breast Cancer-The Dose to the Heart and Heart Subvolumes: What Structures Must Be Contoured in Future Clinical Trials?

BACKGROUND AND PURPOSE: The aim of the present study was to evaluate if it is feasible for experienced radiation oncologists to visually sort out patients with a large dose to the heart. This would facilitate large retrospective data evaluations. And in case of an insufficient visual assessment, to define which structures should be contoured and which structures can be skipped as their dose can be derived from other easily contoured structures for future clinical trials. MATERIAL AND METHODS: Planning CTs of left-sided breast cancer patients treated with 3D-conformal radiotherapy by tangential fields were visually divided into two groups: with an estimated high dose (HiD) and with an estimated low dose (LoD) to the heart. For 46 patients (22 HiD and 24 LoD), the heart, the left ventricle, the left anterior descending artery (LAD), the right coronary artery, and the ramus circumflexus were contoured. A helper structure (HS) around the LAD was generated in order to consider if contouring uncertainties of the LAD could be acceptable. We analyzed the mean dose (Dmean), the maximum dose, the V10, V20, V30, V40, and the length of the LAD that received 20 and 40 Gy. RESULTS: The two groups had a significant different Dmean of the heart (p < 0.001). The average Dmean to the heart was 4.0 ± 1.3 Gy (HiD) and 2.3 ± 0.8 Gy (LoD). The average Dmean to the LAD was 26.2 ± 7.4 Gy (HiD) and 13.0 ± 7.5Gy (LoD) with a very strong positive correlation between Dmean LAD and Dmean HS in both groups. The Dmean heart is not a good surrogate parameter for the dose to the LAD since it might underestimate clinically significant doses in 1/3 of the patients in LoD group. CONCLUSION: A visual assessment of the dose to the heart could be reliable if performed by experienced radiation oncologists. However, the Dmean heart is not always a good surrogate parameter for the dose to the LAD or for the Dmean to the left ventricle. Thus, if specific late toxicities are evaluated, we strongly recommend contouring of the specific heart substructures as a heart Dmean is not highly specific.

Optic toxicity in radiation treatment of meningioma: a retrospective study in 213 patients.

In this retrospective evaluation, we correlated radiation dose parameters with occurrence of optical radiation-induced toxicities. 213 meningioma patients received radiation between 2000 and 2013. Radiation dose and clinical data were extracted from planning systems and patients' files. The range of follow-up period was 2-159 months (median 75 months). Median age of patients was 60 years (range 23-86). There were 163 female and 50 male patients. In 140 cases, at least one of the neuro-optic structures (optic nerves and chiasm) was inside the irradiated target volumes. We found 15 dry eye (7 %) and 24 cataract (11.2 %) cases. Median dose to affected lachrymal glands was 1.47 Gy and median dose to affected lenses was 1.05 Gy. Age and blood cholesterol level in patients with cataract were significantly higher. Patients with dry eye were significantly older. Only two patients with visual problems attributable to radiation treatment were seen. They did not have any risk factors. Maximum and median delivered doses to neuro-optic structures were not higher than 57.30 and 54.60 Gy respectively. Low percentages of cases with radiation induced high grade optic toxicities show that modern treatment techniques and doses are safe. In very few patients with optic side effects, doses to organs at risk were higher than the defined constraint doses. This observation leads to the problem of additional risk factors coming into play. The role of risk factors and safety of higher radiation doses in high grade meningiomas should be investigated in more comprehensive studies.

Study of Preoperative Radiotherapy for Sarcomas of the Extremities with Intensity-Modulation, Image-Guidance and Small Safety-margins (PREMISS).

BACKGROUND: The aim of the trial is to demonstrate that with the use of modern IMRT/IGRT and reduction of safety margins postoperative wound complications can be reduced. METHODS/ DESIGN: The trial is designed as a prospective, monocentric clinical phase II trial. The treatment is performed with helical IMRT on the Tomotherapy HiArt System© or with RapidArc© IMRT as available. All treatments are performed with 6 MV photons and daily online CT-based IGRT. A dose of 50 Gy in 2 Gy single fractions (5 fractions per week) is prescribed. Restaging including MRI of the primary tumor site as well as CT of the thorax/abdomen is planned 4 weeks after RT. PET-examinations or any other imaging can be performed as required clinically. In cases of R1 resection, brachytherapy is anticipated in the 2nd postoperative week. Brachytherapy catheters are implanted into the tumor bed depending on the size and location of the lesion. Surgery is planned 5-6 weeks after completion of neoadjuvant RT. All patients are seen for a first follow-up visit 2 weeks after wound healing is completed, thereafter every 3 months during the first 2 years. The endpoints of the study are evaluated in detail during the first (2 weeks) and second (3 months) follow-up. Functional outcome and QOL are documented prior to treatment and at year 1 and 2. Treatment response and efficacy will be scored according to the RECIST 1.1 criteria. A total patient number of 50 with an expected 20% rate of wound complications were calculated for the study, which translates into a 95% confidence interval of 10.0-33.7% for wound complication rate in a binomial distribution. DISCUSSION: The present study protocol prospectively evaluates the use of IMRT/IGRT for neoadjuvant RT in patients with soft tissue sarcomas of the extremity with the primary endpoint wound complications, which is the major concern with this treatment sequence. Besides complications rates, local control rates and survival rates, as well as QOL, functional outcome and treatment response parameters (imaging and pathology) are part of the protocol. The data of the present PREMISS study will enhance the current literature and support the hypothesis that neoadjuvant RT with IMRT/IGRT offers an excellent risk-benefit ratio in this patient population. TRIAL REGISTRATION: NCT01552239.

Simultaneous integrated vs. sequential boost in VMAT radiotherapy of high-grade gliomas.

BACKGROUND: In 20 patients with high-grade gliomas, we compared two methods of planning for volumetric-modulated arc therapy (VMAT): simultaneous integrated boost (SIB) vs. sequential boost (SEB). The investigation focused on the analysis of dose distributions in the target volumes and the organs at risk (OARs). METHOD: After contouring the target volumes [planning target volumes (PTVs) and boost volumes (BVs)] and OARs, SIB planning and SEB planning were performed. The SEB method consisted of two plans: in the first plan the PTV received 50 Gy in 25 fractions with a 2-Gy dose per fraction. In the second plan the BV received 10 Gy in 5 fractions with a dose per fraction of 2 Gy. The doses of both plans were summed up to show the total doses delivered. In the SIB method the PTV received 54 Gy in 30 fractions with a dose per fraction of 1.8 Gy, while the BV received 60 Gy in the same fraction number but with a dose per fraction of 2 Gy. RESULTS: All of the OARs showed higher doses (Dmax and Dmean) in the SEB method when compared with the SIB technique. The differences between the two methods were statistically significant in almost all of the OARs. Analysing the total doses of the target volumes we found dose distributions with similar homogeneities and comparable total doses. CONCLUSION: Our analysis shows that the SIB method offers advantages over the SEB method in terms of sparing OARs.

Role of membrane Hsp70 in radiation sensitivity of tumor cells.

BACKGROUND: The major stress-inducible heat shock protein 70 (Hsp70) is frequently overexpressed in the cytosol and integrated in the plasma membrane of tumor cells via lipid anchorage. Following stress such as non-lethal irradiation Hsp70 synthesis is up-regulated. Intracellular located Hsp70 is known to exert cytoprotective properties, however, less is known about membrane (m)Hsp70. Herein, we investigate the role of mHsp70 in the sensitivity towards irradiation in tumor sublines that differ in their cytosolic and/or mHsp70 levels. METHODS: The isogenic human colon carcinoma sublines CX(+) with stable high and CX(-) with stable low expression of mHsp70 were generated by fluorescence activated cell sorting, the mouse mammary carcinoma sublines 4 T1 (4 T1 ctrl) and Hsp70 knock-down (4 T1 Hsp70 KD) were produced using the CRISPR/Cas9 system, and the Hsp70 down-regulation in human lung carcinoma sublines H1339 ctrl/H1339 HSF-1 KD and EPLC-272H ctrl/EPLC-272H HSF-1 KD was achieved by small interfering (si)RNA against Heat shock factor 1 (HSF-1). Cytosolic and mHsp70 was quantified by Western blot analysis/ELISA and flow cytometry; double strand breaks (DSBs) and apoptosis were measured by flow cytometry using antibodies against γH2AX and real-time PCR (RT-PCR) using primers and antibodies directed against apoptosis related genes; and radiation sensitivity was determined using clonogenic cell surviving assays. RESULTS: CX(+)/CX(-) tumor cells exhibited similar cytosolic but differed significantly in their mHsp70 levels, 4 T1 ctrl/4 T1 Hsp70 KD cells showed significant differences in their cytosolic and mHsp70 levels and H1339 ctrl/H1339 HSF-1 KD and EPLC-272H ctrl/EPLC-272H HSF-1 KD lung carcinoma cell sublines had similar mHsp70 but significantly different cytosolic Hsp70 levels. γH2AX was significantly up-regulated in irradiated CX(-) and 4 T1 Hsp70 KD with low basal mHsp70 levels, but not in their mHsp70 high expressing counterparts, irrespectively of their cytosolic Hsp70 content. After irradiation γH2AX, Caspase 3/7 and Annexin V were up-regulated in the lung carcinoma sublines, but no significant differences were observed in H1339 ctrl/H1339 HSF-1 KD, and EPLC-272H ctrl/EPLC-272H HSF-1 KD that exhibit identical mHsp70 but different cytosolic Hsp70 levels. Clonogenic cell survival was significantly lower in CX(-) and 4 T1 Hsp70 KD cells with low mHsp70 expression, than in CX+ and 4 T1 ctrl cells, whereas no difference in clonogenic cell survival was observed in H1339 ctrl/H1339 HSF-1 KD and EPLC-272H ctrl/ EPLC-272H HSF-1 KD sublines with identical mHsp70 but different cytosolic Hsp70 levels. CONCLUSION: In summary, our results indicate that mHsp70 has an impact on radiation resistance.

The importance of surrounding tissues and window settings for contouring of moving targets.

AIM: The aim of the study was to assess the importance of surrounding tissues for the delineation of moving targets in tissue-specific phantoms and to find optimal settings for lung, soft tissue, and liver tumors. MATERIALS AND METHODS: Tumor movement was simulated by a water-filled table tennis ball (target volume, TV). Three phantoms were created: corkboards to simulate lung tissue (lung phantom, LunPh), animal fat as fatty soft tissue (fatty tissue phantom, FatPh), and water enhanced with contrast medium as the liver tissue (liver phantom, LivPh). Slow planning three-dimensional compute tomography images (3D-CTs) were acquired with and without phantom movements. One-dimensional tumor movement (1D), three-dimensional tumor movement (3D), as well as a real patient's tumor trajectories were simulated. The TV was contoured using two lung window settings, two soft-tissue window settings, and one liver window setting. The volumes were compared to mathematical calculated values. RESULTS: TVs were underestimated in all phantoms due to movement. The use of soft-tissue windows in the LivPh led to a significant underestimation of the TV (70.8% of calculated TV). When common window settings [LunPh + 200 HU/-1,000 HU (upper window/lower window threshold); FatPh: + 240 HU/-120 HU; LivPh: + 175 HU/+ 50 HU] were used, the contoured TVs were: LivPh, 84.0%; LunPh, 93.2%, and FatPh, 92.8%. The lower window threshold had a significant impact on the size of the delineated TV, whereas changes of the upper threshold led only to small differences. CONCLUSION: The decisive factor for window settings is the lower window threshold (for adequate TV delineation in the lung and fatty-soft tissue it should be lower than density values of surrounding tissue). The use of a liver window should be considered.

Heat Shock Protein 70 (Hsp70) Peptide Activated Natural Killer (NK) Cells for the Treatment of Patients with Non-Small Cell Lung Cancer (NSCLC) after Radiochemotherapy (RCTx) - From Preclinical Studies to a Clinical Phase II Trial.

Heat shock protein 70 (Hsp70) is frequently overexpressed in tumor cells. An unusual cell surface localization could be demonstrated on a large variety of solid tumors including lung, colorectal, breast, squamous cell carcinomas of the head and neck, prostate and pancreatic carcinomas, glioblastomas, sarcomas and hematological malignancies, but not on corresponding normal tissues. A membrane (m)Hsp70-positive phenotype can be determined either directly on single cell suspensions of tumor biopsies by flow cytometry using cmHsp70.1 monoclonal antibody or indirectly in the serum of patients using a novel lipHsp70 ELISA. A mHsp70-positive tumor phenotype has been associated with highly aggressive tumors, causing invasion and metastases and resistance to cell death. However, natural killer (NK), but not T cells were found to kill mHsp70-positive tumor cells after activation with a naturally occurring Hsp70 peptide (TKD) plus low dose IL-2 (TKD/IL-2). Safety and tolerability of ex vivo TKD/IL-2 stimulated, autologous NK cells has been demonstrated in patients with metastasized colorectal and non-small cell lung cancer (NSCLC) in a phase I clinical trial. Based on promising clinical results of the previous study, a phase II randomized clinical study was initiated in 2014. The primary objective of this multicenter proof-of-concept trial is to examine whether an adjuvant treatment of NSCLC patients after platinum-based radiochemotherapy (RCTx) with TKD/IL-2 activated, autologous NK cells is clinically effective. As a mHsp70-positive tumor phenotype is associated with poor clinical outcome only mHsp70-positive tumor patients will be recruited into the trial. The primary endpoint of this study will be the comparison of the progression-free survival of patients treated with ex vivo activated NK cells compared to patients who were treated with RCTx alone. As secondary endpoints overall survival, toxicity, quality-of-life, and biological responses will be determined in both study groups.

Stereotactic radiation therapy for liver metastases: factors affecting local control and survival.

PURPOSE: To report on outcome and toxicity of stereotactic body radiotherapy (SBRT) for liver metastases in patients not eligible for surgery. METHODS: From 2000 to 2009, 74 patients with 91 liver metastases from different primaries have been treated with SBRT at our institution. Median planning target volume was 123 ccm (range: 10.6-1074 ccm). Treatment consisted of 3-5 fractions with 5-12.5 Gy/ fraction prescribed to the surrounding 60-95% isodose with daily image guidance. Regular follow-up included CT or MRI imaging until tumor progression. RESULTS: Median local recurrence-free interval was 23 months with a local control rate of 74.7%, 48.3% and 48.3% after 1, 2 and 3 years. Only minimum biologically effective dose (BED) to gross tumor volume (GTV) remained as independent significant factor for local control in multivariate analysis. No local recurrences were observed in lesions (n = 12) which received a minimal BED to the GTV of 120 Gy. Including 26 local recurrences, 67 patients (91%) showed disease progression after SBRT with a median time of 5 months. Median overall survival was 27 months with survival rates of 77%, 30% and 27% at 1, 3 and 5 years. On multivariate analysis only GTV volume remained as independent significant prognostic factor for overall survival (p = 0.002). No grade 3 to 5 acute toxicity and no grade 4 or 5 late toxicity occurred. CONCLUSION: SBRT for liver metastases was well tolerated in this non-selected patient cohort and yielded good local control despite the considerable size of most lesions treated. Long-term survival is possible after SBRT.

Long-term outcome after highly advanced single-dose or fractionated radiotherapy in patients with vestibular schwannomas - pooled results from 3 large German centers.

PURPOSE: To evaluate long-term clinical outcome and determine prognostic factors for local-control, hearing preservation and cranial nerve toxicity in 449 patients treated for 451 vestibular schwannomas (VS) with radiosurgery (n=169; 38%) or fractionated stereotactic radiotherapy (FSRT; n=291; 62%). METHODS AND MATERIALS: 245 patients were male (55%), and 204 were female (45%). Median age was 60 years (range 17-88 years). Median tumor diameter was 15mm. For FSRT, a median dose of 57.6Gy in median single doses of 1.8Gy was applied. For SRS, median dose was 13Gy. The median follow-up time was 67 months. RESULTS: Local control was 97% at 36 months, 95% at 60 months, and 94% at 120 months with no difference between FSRT and SRS (p=0.39). "Useful hearing" was present 46%. After RT, "useful hearing" was preserved in 85% of the patients. Loss of useful hearing was observed in the FSRT group in 14%, and in the SRS group in 16% of the patients. For patients treated with SRS ⩽13Gy, useful hearing deterioration was 13%. For trigeminal and facial nerve toxicity, there was no difference between FSRT and SRS. CONCLUSION: Supported by this large multicentric series, both SRS and FSRT can be recommended for the treatment of VS. SRS application is limited by tumor size, and is associated with a steep dose-response-curve. When chosen diligently based on tumor volume, pre-treatment characteristics and volume-dependent dose-prescription in SRS (⩽13Gy), both treatments may be considered equally effective.

Stereotactic body radiotherapy for centrally located stage I NSCLC: a multicenter analysis.

PURPOSE: The purpose of this work is to analyze patterns of care and outcome after stereotactic body radiotherapy (SBRT) for centrally located, early-stage, non-small cell lung cancer (NSCLC) and to address the question of potential risk for increased toxicity in this entity. METHODS AND MATERIALS: A total of 90 patients with centrally located NSCLC were identified among 613 cases in a database of 13 German and Austrian academic radiotherapy centers. The outcome of centrally located NSCLC was compared to that of cases with peripheral tumor location from the same database. RESULTS: Patients with central tumors most commonly presented with UICC stage IB (50 %), while the majority of peripheral lesions were stage IA (56 %). Average tumor diameters were 3.3 cm (central) and 2.8 cm (peripheral). Staging PET/CT was available for 73 and 74 % of peripheral and central tumors, respectively. Biopsy was performed in 84 % (peripheral) and 88 % (central) of cases. Doses varied significantly between central and peripheral lesions with a median BED10 of 72 Gy and 84 Gy, respectively (p < 0.001). Fractionation differed as well with medians of 5 (central) and 3 (peripheral) fractions (p < 0.001). In the Kaplan-Meier analysis, 3-year actuarial overall survival was 29 % (central) and 51 % (peripheral; p = 0.004) and freedom from local progression was 52 % (central) and 84 % (peripheral; p < 0.001). Toxicity after treatment of central tumors was low with no grade III/IV and one grade V event. Mortality rates were 0 and 1 % after 30 and 60 days, respectively. CONCLUSION: Local tumor control in patients treated with SBRT for centrally located, early-stage NSCLC was favorable, provided ablative radiation doses were prescribed. This was, however, not the case in the majority of patients, possibly due to concerns about treatment-related toxicity. Reported toxicity was low, but prospective trials are needed to resolve the existing uncertainties and to establish safe high-dose regimens for this cohort of patients.

11C-Choline PET/pathology image coregistration in primary localized prostate cancer.

PURPOSE: The aim of this study was to develop a methodology for the comparison of pathology specimens after prostatectomy (post-S) with PET images obtained before surgery (pre-S). This method was used to evaluate the merit of (11)C-choline PET/CT for delineation of gross tumour volume (GTV) in prostate cancer (PC). METHODS: In 28 PC patients, (11)C-choline PET/CT was performed before surgery. PET/CT data were coregistered with the pathology specimens. GTV on PET images (GTV-PET) was outlined automatically and corrected manually. Tumour volume in the prostate (TVP) was delineated manually on the pathology specimens. Based on the coregistered PET/pathology images, the following parameters were assessed: SUVmax and SUVmean in the tumoral and nontumoral prostate (NP), GTV-PET (millilitres) and TVP (millilitres). RESULTS: PET/pathology image coregistration was satisfactory. Mean SUVmax in the TVP was lower than in the NP: 5.0 and 5.5, respectively (p = 0.093). Considering the entire prostate, SUVmax was located in the TVP in two patients, in the TVP and NP in 12 patients and exclusively in NP in 14 patients. Partial overlap the TVP and GTV-PET was seen in 71% of patients, and complete overlap in 4%. CONCLUSION: PET/pathology image coregistration can be used for evaluation of different imaging modalities. (11)C-Choline PET failed to distinguish tumour from nontumour tissue.

Long-term outcomes of trimodality treatment for squamous cell carcinoma of the esophagus with cisplatin and/or 5-FU: more than 20 years' experience at a single institution.

PURPOSE: The purpose of this article is to report the outcome of neoadjuvant radiochemotherapy (N-RCT) + surgery in patients with squamous cell carcinoma of the esophagus at a single institution. METHODS: We retrospectively reviewed data from patients who were referred to our department for N-RCT. From 1988­2011, 103 patients were treated with N-RCT with cisplatin and/or 5-fluorouracil (5-FU). Group 1: (n = 55) from 1988­2006 with 39.6­40 Gy and 5-FU with (n = 17) or without cisplatin (n = 38). Group 2: from 2003­2010 with 44­45 Gy and 5-FU with (n = 40) or without cisplatin (n = 8). All patients underwent radical resection with reconstruction according to tumor location and 2-field lymph node dissection. The degree of histomorphologic regression was defined as grade 1a (pCR, 0 % residual tumor), grade 1b (pSTR, < 10 % residual tumor), grade 2 (10­50 % residual tumor), and grade 3 (> 50 % residual tumor). RESULTS: Median follow-up time from the start of N-RCT was 100 months (range 2­213 months). The median overall survival (OS) for the whole cohort was 42 months and the 5-year OS was 45 ± 5 %. In the multivariate analysis, worse ECOG performance status (p < 0.001), weight loss > 10 % before the start of the N-RCT (p = 0.025), higher pT category (p = 0.001), and grade 2/3 pathologic remission (p < 0.001) were significantly associated with a poor OS. PCR and pSTR rates for group 1 were 36 % and 18 % compared to 53 % and 22 % for group 2 (p = 0.011). There was a tendency for a better outcome in group 2 patients without statistical significance. The 5-year OS, disease-free survival and recurrent-free survival were 36 ± 7 %, 35 ± 6, and 36 ± 7 % for group 1 and 55 ± 7, 49 ± 7, and 53 ± 7 in group 2 (p = 0.117, p = 0.124, and p = 0.087). There was no significant difference between the two groups considering the postoperative morbidity and mortality. CONCLUSION: Higher radiation doses and more use of simultaneous cisplatin lead to higher pathologic response rates to N-RCT and may be associated with better survival outcomes. Prospective controlled trials are needed to assess the true value of intensified N-RCT regimens.

Radiosensitization of wildtype p53 cancer cells by the MDM2-inhibitor PXN727 is associated with altered heat shock protein 70 (Hsp70) levels.

The oncoprotein MDM2 (murine double minute 2) is often overexpressed in human tumors and thereby attenuates the function of the tumor suppressor p53. In this study, we investigated the effects of the novel MDM2-inhibitor PXN727 on p53 activation, cell proliferation, cell cycle distribution and radiosensitivity. Since the localization of heat shock protein 70 (Hsp70) exerts different effects on radioresistance of tumor cells, we investigated the impact of PXN727 on intracellular, membrane, and secreted Hsp70 levels. We could show that PXN727 exerts its effects on wildtype p53 (HCT116 p53⁺/⁺, A549) but not p53 depleted (HCT116 p53⁻/⁻) or mutated (FaDu) tumor cells. PXN727 activates p53, induces the expression of p21, reduces the proportion of cells in the radioresistant S-phase and induces senescence. Radiosensitivity was significantly increased by PXN727 in HCT116 p53⁺/⁺ tumor cells. Furthermore, PXN727 causes a downregulation of Hsp70 membrane expression and an upregulated secretion of Hsp70 in wildtype p53 tumor cells. Our data suggest that re-activation of p53 by MDM2-inhibition modulates Hsp70 membrane expression and secretion which might contribute to the radiosensitizing effect of the MDM2-inhibitor PXN727.

Monitoring PAI-1 and VEGF levels in 6 human squamous cell carcinoma xenografts during fractionated irradiation.

PURPOSE: Previous studies have shown that the plasminogen activator inhibitor type-1 (PAI-1) and vascular endothelial growth factor (VEGF) are regulated by hypoxia and irradiation and are involved in neoangiogenesis. The aim of this study was to determine in vivo whether changes in PAI-1 and VEGF during fractionated irradiation could predict for radiation resistance. METHODS AND MATERIALS: Six xenografted tumor lines from human squamous cell carcinomas (HSCC) of the head and neck were irradiated with 0, 3, 5, 10, and 15 daily fractions of 2 Gy. The PAI-1 and VEGF antigen levels in tumor lysates were determined by enzyme-linked immunosorbent assay kits. The amounts of PAI-1 and VEGF were compared with the dose to cure 50% of tumors (TCD(50)). Colocalization of PAI-1, pimonidazole (hypoxia), CD31 (endothelium), and Hoechst 33342 (perfusion) was examined by immunofluorescence. RESULTS: Human PAI-1 and VEGF (hVEGF) expression levels were induced by fractionated irradiation in UT-SCC-15, UT-SCC-14, and UT-SCC-5 tumors, and mouse VEGF (msVEGF) was induced only in UT-SCC-5 tumors. High hVEGF levels were significantly associated with radiation sensitivity after 5 fractions (P=.021), and high msVEGF levels were significantly associated with radiation resistance after 10 fractions (P=.007). PAI-1 staining was observed in the extracellular matrix, the cytoplasm of fibroblast-like stroma cells, and individual tumor cells at all doses of irradiation. Colocalization studies showed PAI-1 staining close to microvessels. CONCLUSIONS: These results indicate that the concentration of tumor-specific and host-specific VEGF during fractionated irradiation could provide considerably divergent information for the outcome of radiation therapy.

Do we need daily image-guided radiotherapy by megavoltage computed tomography in head and neck helical tomotherapy? The actual delivered dose to the spinal cord.

PURPOSE: To quantify the actual delivered dose to the cervical spinal cord with different image-guided radiotherapy (IGRT) approaches during head and neck (HN) cancer helical tomotherapy. METHODS AND MATERIALS: Twenty HN patients (HNpts) treated with bilateral nodal irradiation were analyzed. Daily megavoltage computed tomography MVCT) scans were performed for setup purposes. The maximum dose on the planning CT scan (plan-Dmax) and the magnitude and localization of the actual delivered Dmax (a-Dmax) were analyzed for four scenarios: daily image-guided radiotherapy (dIGRT), twice weekly IGRT (2×WkIGRT), once weekly IGRT (1×WkIGRT), and no IGRT at all (non-IGRT). The spinal cord was recontoured on 236 MVCTs for each scenario (total, 944 fractions), and the delivered dose was recalculated for each fraction (fx) separately. RESULTS: Fifty-one percent of the analyzed fx for dIGRT, 56% of the analyzed fx for the 2×WkIGRT, 62% of the analyzed fx for the 1×WkIGRT, and 63% of the analyzed fx for the non-IGRT scenarios received a higher a-Dmax than the plan-Dmax. The median increase of dose in these fx was 3.3% more for dIGRT, 5.8% more for 2×WkIGRT, 10.0% more for 1×WkIGRT, and 9.5% more for non-IGRT than the plan-Dmax. The median spinal cord volumes receiving a higher dose than the plan-Dmax were 0.02 cm³ for dIGRT, 0.11 cm³ for 2×WkIGRT, 0.31 cm³ for 1×WkIGRT, and 0.22 cm³ for non-IGRT. Differences between the dIGRT and all other scenarios were statistically significant (p < 0.05). CONCLUSIONS: Compared to the Dmax of the initial plan, daily IGRT had the smallest increase in dose. Furthermore, daily IGRT had the lowest proportion of fractions and the smallest volumes affected by a dose that was higher than the planned dose. For patients treated with doses close to the tolerance dose of the spinal cord, we recommend daily IGRT. For all other cases, twice weekly IGRT is sufficient.