Model-based Segmentation and Fusion of 3D Computed Tomography and 3D Ultrasound of the Eye for Radiotherapy Planning

Computed Tomography (CT) represents the standard imaging modality for tumor volume delineation for radiotherapy treatment planning of retinoblastoma despite some inherent limitations. CT scan is very useful in providing information on physical density for dose calculation and morphological volumetric information but presents a low sensitivity in assessing the tumor viability. On the other hand, 3D ultrasound (US) allows a highly accurate definition of the tumor volume thanks to its high spatial resolution but it is not currently integrated in the treatment planning but used only for diagnosis and follow-up. Our ultimate goal is an automatic segmentation of gross tumor volume (GTV) in the 3D US, the segmentation of the organs at risk (OAR) in the CT and the registration of both modalities. In this paper, we present some preliminary results in this direction. We present 3D active contour-based segmentation of the eye ball and the lens in CT images; the presented approach incorporates the prior knowledge of the anatomy by using a 3D geometrical eye model. The automated segmentation results are validated by comparing with manual segmentations. Then, we present two approaches for the fusion of 3D CT and US images: (i) landmark-based transformation, and (ii) object-based transformation that makes use of eye ball contour information on CT and US images.

A phase 2 randomized trial of radiotherapy (RT) plus panitumumab compared to chemoradiotherapy in patients with unresected, locally advanced squamous cell carcinoma of the head and neck (SCCHN): interim pooled safety analysis

Background: Panitumumab (pmab), a fully human monoclonal antibody against the epidermal growth factor receptor (EGFR), is indicated as monotherapy for treatment of metastatic colorectal cancer. This ongoing study is designed to assess the efficacy and safety of pmab in combination with radiotherapy (PRT) compared to chemoradiotherapy (CRT) as initial treatment of unresected, locally advanced SCCHN (ClinicalTrials.gov Identifier: NCT00547157). Methods: This is a phase 2, open-label, randomized, multicenter study. Eligible patients (pts) were randomized 2:3 to receive cisplatin 100 mg/m2 on days 1 and 22 of RT or pmab 9.0 mg/kg on days 1, 22, and 43. Accelerated RT (70 to 72 Gy − delivered over 6 to 6.5 weeks) was planned for all pts and was delivered either by intensity-modulated radiation therapy (IMRT) modality or by three-dimensional conformal (3D-CRT) modality. The primary endpoint is local-regional control (LRC) rate at 2 years. Key secondary endpoints include PFS, OS, and safety. An external, independent data monitoring committee conducts planned safety and efficacy reviews during the course of the trial. Results: Pooled data from this planned interim safety analysis includes the first 52 of the 150 planned pts; 44 (84.6%) are male; median (range) age is 57 (33−77) years; ECOG PS 0: 65%, PS 1: 35%; 20 (39%) pts received IMRT, and 32 (61%) pts received 3D-CRT. Fifty (96%) pts completed RT, and 50 pts received RT per protocol without a major deviation. The median (range) total RT dose administered was 72 (64−74) Gy. The most common grade _ 3 adverse events graded using the CTCAE version 3.0 are shown (Table). Conclusions: After the interim safety analysis, CONCERT-2 continues per protocol. Study enrollment is estimated to be completed by October 2009.

From radiobiology to technology: what is changing in radiotherapy for prostate cancer.

In the last decades, new technologies have been introduced in the daily clinical practice of the radiation oncologist: 3D-Conformal radiotherapy (RT) became almost universally available, thereafter, intensity modulated RT (IMRT) gained large diffusion, due to its potential impact in improving the clinical outcomes, and more recently, helical and volumetric arc IMRT with image-guided RT are becoming more and more diffused and used for prostate cancer patients. The conventional dose-fractionation results to be the best compromise between the efficacy and the safety of the treatment, but combining new techniques, modern RT allows to overcame one of the major limits of the 'older' RT: the impossibility of delivering higher total doses and/or high dose/fraction. The evidences regarding radiobiology, clinical and technological evolution of RT in prostate cancer have been reported and discussed.

Contribution of PaTrin-2 in Radiotherapy with Temozolomide for the Treatment of Glioblastoma Expressing MGMT

Purpose/Objective(s): Current standard treatment of glioblastoma is radiotherapy (RT) concomitant with temozolomide (TMZ), an alkylating agent. O6-methylguanine-DNA methyltransferase (MGMT) expression is a major mechanism of resistance to Proceedings of the alkylating agent chemotherapy, and MGMT gene promoter methylation (present in 30-45 % of tumors) has been shown to be predictive for tumor response to TMZ therapy. MGMT, an exhaustible repair protein can be depleted by specific inhibitors such as O6- benzylguanine or the non-toxic O6-(4-bromothenyl)guanine (PaTrin-2). Here we have studied the efficacy of the combination of TMZ, RT, and PaTrin-2 to improve the treatment outcome in glioblastoma expressing MGMT. Materials/Methods: 3 glioblastoma lines were chosen: LN18 and T98G expressing MGMT and U251 lacking MGMT expression. A shRNA approach was used to selectively and permanently knockdown level of MGMT in LN18 line. Cells were treated with 10 mM PaTrin-2. After 2 h, various concentrations of TMZ were added, cells were incubated for 24 h, and clonogenic assays were performed. After the same PaTrin-2 pretreatment and 100 mM TMZ exposure, cells were plated 4 h before irradiation with increasing RT doses of up to 6 Gy. Clonogenic survival was assessed after 14 days. Results: Western blot analysis confirmed that reduction of MGMT expression was achieved in LN18A1 expressing MGMT-targeting shRNA. The shRNA non-targeting control sequence did not influenceMGMTprotein level (LN18NT). PaTrin-2 showed no toxicity at 10 mMon the 5 cell lines. TMZ induced up to 70 and 97%of cell death on LN18A1 and U251, respectively, but was not toxic up to 50 mMfor T98G, LN18, and LN18NT. Up to 53%increased TMZ toxicity was observed on the 5 cell lines when treated with the 2 drugs. Irradiation of the 5 lines treated or not with PaTrin-2 showed no survival difference at any irradiation dose. When LN18A1 and U251 cells were irradiated post TMZ treatment, an up to 2.5 and 139.4 fold increase in toxicity, respectively, was observed compared to un-pretreated controls. By contrast, TMZ pretreatment did not increase irradiation toxicity on T98G, LN18, and LN18NT. When cells were incubated with PaTrin-2 and TMZ before the irradiation, up to 3.7, 3.9, 5.8, 6.6 and 348.5 fold increase in toxicity was observed compared to controls on LN18, LN18NT, LN18A1, T98G and U251, respectively. Conclusions: We present here results of TMZ and PaTrin-2 combination ± RT on glioblastoma lines. U251 and LN18A1 cells were much more sensitive to TMZ than LN18, LN18NT, and T98G. PaTrin-2 enhanced the toxicity of TMZ on the MGMT expressing glioblastoma lines. RT further increased TMZ and PaTrin-2 efficacy. These results are encouraging for the treatment of patients with glioblastoma expressing MGMT who have the worst prognosis and respond poorly to RT combined with TMZ.

Current developments in the radiotherapy approach to elderly and frail patients with glioblastoma multiforme.

The benefit of postoperative radiotherapy (RT) has been demonstrated in elderly patients aged 65 years or older with glioblastoma multiforme. Hypofractionated RT schedules can reduce the time and morbidity of treatment while maintaining comparable survival outcomes to lengthy conventional RT. Current international randomized clinical trials are studying the optimized hypofractionated RT regimens, hypofractionated RT in comparison with temozolomide chemotherapy and hypofractionated RT in comparison with the same RT plus temozolomide. Given the guarded prognosis of the elderly and frail patients, quality of life and side effects of treatment should be closely examined. As more than half of cancers in the world occur in developing countries, hypofractionated RT could be better utilized as a cost-effective treatment for this group of patients.

Cancers du sein : comment associer l'hormonothérapie et la radiothérapie en situation adjuvante ? [How to combine hormonotherapy and radiation treatment in adjuvant breast cancer ?]

L'hormonoradiothérapie concomitante est utilisée depuis plusieurs années en pratique clinique quotidienne dans les cancers localement évolués de la prostate. Le transfert de ce concept en pathologie mammaire a été très peu rapporté dans la littérature, mais semble pourtant licite devant l'hormonodépendance fréquente des cancers du sein et la synergie potentielle de ces deux armes thérapeutiques. En situation adjuvante, deux stratégies sont actuellement utilisées : la prescription d'un inhibiteur de l'aromatase d'emblée ou après un délai plus ou moins long de tamoxifène. En pratique, ces molécules peuvent donc interagir avec la radiothérapie adjuvante. Les études rétrospectives récemment publiées n'ont pas mis en évidence de différence significative sur l'incidence des évènements, notamment locorégionaux, de l'association concomitante ou séquentielle du tamoxifène à la radiothérapie. La toxicité de l'association reste discutable en termes de fibroses sous-cutanée et pulmonaire. Il semble que le tamoxifène aggraverait les séquelles postradiques uniquement chez les patientes prédisposées à souffrir d'effets tardifs de la radiothérapie et identifiées par un test prédictif biologique. La prudence reste donc encore de mise du moins pour ces patientes. Cet article détaille les avantages et les risques de l'utilisation concomitante de la radiothérapie et de l'hormonothérapie adjuvantes des cancers localisés du sein. Combined radiation and hormone therapies have become common clinical practice in recent years for locally-advanced prostate cancers. The use of such concomitant therapy in the treatment of breast disease has been infrequently reported in the literature, but seems justified given the common hormonal dependence of breast cancer and the potential synergistic effect of these two treatment modalities. As adjuvant therapy, two strategies are used in daily clinical practice: upfront aromatase inhibitors or sequentially after a variable delay of tamoxifen. These molecules may, thus, interact with radiotherapy. Retrospectives studies recently published did not show any differences in terms of locoregional recurrences between concurrent or sequential radiohormonotherapy. Lung and skin fibroses due to concurrent treatment are still under debate. Nevertheless, late side effects appeared to be increased by such a treatment, particularly in hypersensitive patients identified at risk by the lymphocyte predictive test. Concurrent radiohormonotherapy should, thus, be delivered cautiously at least for these patients. This article details the potent advantages and risks of concurrent use of adjuvant hormonotherapy and radiotherapy in localized breast cancers.

Dynamic changes in brain functional connectivity during concurrent dual-task performance.

This study investigated the spatial, spectral, temporal and functional proprieties of functional brain connections involved in the concurrent execution of unrelated visual perception and working memory tasks. Electroencephalography data was analysed using a novel data-driven approach assessing source coherence at the whole-brain level. Three connections in the beta-band (18-24 Hz) and one in the gamma-band (30-40 Hz) were modulated by dual-task performance. Beta-coherence increased within two dorsofrontal-occipital connections in dual-task conditions compared to the single-task condition, with the highest coherence seen during low working memory load trials. In contrast, beta-coherence in a prefrontal-occipital functional connection and gamma-coherence in an inferior frontal-occipitoparietal connection was not affected by the addition of the second task and only showed elevated coherence under high working memory load. Analysis of coherence as a function of time suggested that the dorsofrontal-occipital beta-connections were relevant to working memory maintenance, while the prefrontal-occipital beta-connection and the inferior frontal-occipitoparietal gamma-connection were involved in top-down control of concurrent visual processing. The fact that increased coherence in the gamma-connection, from low to high working memory load, was negatively correlated with faster reaction time on the perception task supports this interpretation. Together, these results demonstrate that dual-task demands trigger non-linear changes in functional interactions between frontal-executive and occipitoparietal-perceptual cortices.

The essential role of radiotherapy in the treatment of Merkel cell carcinoma: a study from the Rare Cancer Network.

PURPOSE: To evaluate the role of postoperative radiotherapy (RT) in Merkel cell carcinoma (MCC). METHODS AND MATERIALS: A retrospective multicenter study was performed in 180 patients with MCC treated between February 1988 and September 2009. Patients who had had surgery alone were compared with patients who received surgery and postoperative RT or radical RT. Local relapse-free survival (LRFS), regional relapse-free survival (RRFS), and distant metastasis-free survival (DMFS) rates were assessed together with disease-free survival (DFS), cancer-specific survival (CSS), and overall survival (OS) rates. RESULTS: Seventy-nine patients were male and 101 patients were female, and the median age was 73 years old (range, 38-93 years). The majority of patients had localized disease (n = 146), and the remaining patients had regional lymph node metastasis (n = 34). Forty-nine patients underwent surgery for the primary tumor without postoperative RT to the primary site; the other 131 patients received surgery for the primary tumor, followed by postoperative RT (n = 118) or a biopsy of the primary tumor followed by radical RT (n = 13). Median follow-up was 5 years (range, 0.2-16.5 years). Patients in the RT group had improved LRFS (93% vs. 64%; p < 0.001), RRFS (76% vs. 27%; p < 0.001), DMFS (70% vs. 42%; p = 0.01), DFS (59% vs. 4%; p < 0.001), and CSS (65% vs. 49%; p = 0.03) rates compared to patients who underwent surgery for the primary tumor alone; LRFS, RRFS, DMFS, and DFS rates remained significant with multivariable Cox regression analysis. However OS was not significantly improved by postoperative RT (56% vs. 46%; p = 0.2). CONCLUSIONS: After multivariable analysis, postoperative RT was associated with improved outcome and seems to be an important component in the multimodality treatment of MCC.

Radiotherapy suppresses angiogenesis in mice through TGF-betaRI/ALK5-dependent inhibition of endothelial cell sprouting.

BACKGROUND: Radiotherapy is widely used to treat cancer. While rapidly dividing cancer cells are naturally considered the main target of radiotherapy, emerging evidence indicates that radiotherapy also affects endothelial cell functions, and possibly also their angiogenic capacity. In spite of its clinical relevance, such putative anti-angiogenic effect of radiotherapy has not been thoroughly characterized. We have investigated the effect of ionizing radiation on angiogenesis using in vivo, ex vivo and in vitro experimental models in combination with genetic and pharmacological interventions. PRINCIPAL FINDINGS: Here we show that high doses ionizing radiation locally suppressed VEGF- and FGF-2-induced Matrigel plug angiogenesis in mice in vivo and prevented endothelial cell sprouting from mouse aortic rings following in vivo or ex vivo irradiation. Quiescent human endothelial cells exposed to ionizing radiation in vitro resisted apoptosis, demonstrated reduced sprouting, migration and proliferation capacities, showed enhanced adhesion to matrix proteins, and underwent premature senescence. Irradiation induced the expression of P53 and P21 proteins in endothelial cells, but p53 or p21 deficiency and P21 silencing did not prevent radiation-induced inhibition of sprouting or proliferation. Radiation induced Smad-2 phosphorylation in skin in vivo and in endothelial cells in vitro. Inhibition of the TGF-beta type I receptor ALK5 rescued deficient endothelial cell sprouting and migration but not proliferation in vitro and restored defective Matrigel plug angiogenesis in irradiated mice in vivo. ALK5 inhibition, however, did not rescue deficient proliferation. Notch signaling, known to hinder angiogenesis, was activated by radiation but its inhibition, alone or in combination with ALK5 inhibition, did not rescue suppressed proliferation. CONCLUSIONS: These results demonstrate that irradiation of quiescent endothelial cells suppresses subsequent angiogenesis and that ALK5 is a critical mediator of this suppression. These results extend our understanding of radiotherapy-induced endothelial dysfunctions, relevant to both therapeutic and unwanted effects of radiotherapy.

Decrease in hemoglobin levels following surgery influences the outcome in head and neck cancer patients treated with accelerated postoperative radiotherapy.

AIM: To assess the influence of hemoglobin (Hb) levels in locally advanced head and neck cancer (LAHNC) patients treated with surgery and postoperative radiotherapy (PORT). MATERIAL AND METHODS: Pre- and postoperative Hb levels were collected in 79 patients treated with surgery followed by accelerated PORT for LAHNC. Median follow-up was 52 months (range 12-95 months). RESULTS AND DISCUSSION: Four-year overall survival (OS) rate was 51%. Neither pre- nor postoperative Hb level (&lt;120 or 130 g/l in women or men, respectively) influenced the outcome. However, when Hb decrease between pre- and postoperative Hb values was taken into account, 4-year OS was significantly higher in patients with Hb difference less than 38 g/l (quartile value) compared with those with Hb decrease 38 g/l or more (61% versus 16%, P = 0.008). CONCLUSION: Decrease in Hb level by more than 38 g/l after surgery secondary to blood loss influences the outcome when postoperative RT is indicated.

Effects of radiotherapy with concomitant and adjuvant temozolomide versus radiotherapy alone on survival in glioblastoma in a randomised phase III study: 5-year analysis of the EORTC-NCIC trial.

BACKGROUND: In 2004, a randomised phase III trial by the European Organisation for Research and Treatment of Cancer (EORTC) and National Cancer Institute of Canada Clinical Trials Group (NCIC) reported improved median and 2-year survival for patients with glioblastoma treated with concomitant and adjuvant temozolomide and radiotherapy. We report the final results with a median follow-up of more than 5 years. METHODS: Adult patients with newly diagnosed glioblastoma were randomly assigned to receive either standard radiotherapy or identical radiotherapy with concomitant temozolomide followed by up to six cycles of adjuvant temozolomide. The methylation status of the methyl-guanine methyl transferase gene, MGMT, was determined retrospectively from the tumour tissue of 206 patients. The primary endpoint was overall survival. Analyses were by intention to treat. This trial is registered with Clinicaltrials.gov, number NCT00006353. FINDINGS: Between Aug 17, 2000, and March 22, 2002, 573 patients were assigned to treatment. 278 (97%) of 286 patients in the radiotherapy alone group and 254 (89%) of 287 in the combined-treatment group died during 5 years of follow-up. Overall survival was 27.2% (95% CI 22.2-32.5) at 2 years, 16.0% (12.0-20.6) at 3 years, 12.1% (8.5-16.4) at 4 years, and 9.8% (6.4-14.0) at 5 years with temozolomide, versus 10.9% (7.6-14.8), 4.4% (2.4-7.2), 3.0% (1.4-5.7), and 1.9% (0.6-4.4) with radiotherapy alone (hazard ratio 0.6, 95% CI 0.5-0.7; p<0.0001). A benefit of combined therapy was recorded in all clinical prognostic subgroups, including patients aged 60-70 years. Methylation of the MGMT promoter was the strongest predictor for outcome and benefit from temozolomide chemotherapy. INTERPRETATION: Benefits of adjuvant temozolomide with radiotherapy lasted throughout 5 years of follow-up. A few patients in favourable prognostic categories survive longer than 5 years. MGMT methylation status identifies patients most likely to benefit from the addition of temozolomide. FUNDING: EORTC, NCIC, Nélia and Amadeo Barletta Foundation, Schering-Plough.

External beam radiotherapy ± chemotherapy in the treatment of anal canal cancer: a single-institute long-term experience on 100 patients.

One-hundred patients treated with curative radiotherapy (RT) ± chemotherapy (CT) for an anal canal carcinoma (T1-4N0-3M0) were retrospectively analyzed. Five- and 10-year local control (LC) rates were 73% and 67%, respectively. Acute and late G3-G4 toxicity rates were 32% and 12%, respectively. Two patients underwent a colostomy for a G4 anal toxicity. This study confirms the outcomes of RT ± CT in the treatment of anal canal cancer. Concomitant CT and LC statistically influenced Overall Survival and Colostomy-Free Survival. CT also statistically reduced the risk of nodal relapse. High rates of acute skin toxicity impose tailored volumes and techniques of irradiation.

Mikrovaskulär anastomosierte Transplantate : Verwendung in der Kopf-Hals-Region nach Bestrahlung und Gefäßdepletion [Grafts with microvascular anastomosis : Their use in the head and neck region following radiotherapy and vessel depletion].

Surgical tumor removal is often the treatment of choice in patients with head and neck squamous cell carcinoma. Depending on the extent of tumor resection, large defects are often produced in the individual head and neck regions, necessitating reconstructive surgery to avoid further functional impairment. In principle, this decision depends on the size and location of the defect, the aesthetic importance of the region and the functional significance of the area to be replaced. Reconstructive free flap procedures in patients who have undergone radiotherapy or exhibit vessel depletion in the neck due to multiple previous surgical interventions are particularly challenging. In order to ensure the best possible outcomes of surgical oncology therapies under difficult circumstances, this paper discusses the important factors and variables that can increase the success rate of microvascular grafts in irradiated or multiply resected patients.