G. Fallone

Association of DNA Repair and Steroid Metabolism Gene Polymorphisms with Clinical Late Toxicity in Patients Treated with Conformal Radiotherapy for Prostate Cancer

Objective: To explore the possible relationship between single nucleotide polymorphisms (SNP) in candidate genes encoding DNA damage recognition/repair/response and steroid metabolism proteins with respect to clinical radiation toxicity in a retrospective cohort of patients previously treated with three-dimensional conformal radiotherapy (3-DCRT) for prostate cancer. Experimental Design: One hundred twenty-four patients with prostate cancer underwent 3-DCRT at our institution between September 1996 and December 2000. Of these, 83 consented for follow-up of blood sampling and SNP analysis. Twenty-eight patients were documented as having experienced grade ≥2 late bladder or rectal toxicity (scoring system of Radiation Therapy Oncology Group) on at least one follow-up visit. We analyzed 49 SNPs in BRCA1, BRCA2, ESR1, XRCC1, XRCC2, XRCC3, NBN, RAD51, RAD52, LIG4, ATM, BCL2, TGFB1, MSH6, ERCC2, XPF, NR3C1, CYP1A1, CYP2C9, CYP2C19, CYP3A5, CYP2D6, CYP11B2, and CYP17A1 genes using the Pyrosequencing technique. Results: Significant univariate associations with late rectal or bladder toxicity (grade ≥2) were found for XRCC3 (A>G 5′ untranslated region NT 4541), LIG4 (T>C Asp568Asp), MLH1 (C>T, Val219Ile), CYP2D6*4 (G>A splicing defect), mean rectal and bladder dose, dose to 30% of rectum or bladder, and age <60 years. On Cox multivariate analysis, significant associations with toxicity were found for LIG4 (T>C, Asp568Asp), ERCC2 (G>A, Asp711Asp), CYP2D6*4 (G>A, splicing defect), mean bladder dose >60 Gy, and dose to 30% of rectal volume >75 Gy. Conclusions: In this study, we identified SNPs in LIG4, ERCC2, and CYP2D6 genes as putative markers to predict individuals at risk for complications arising from radiation therapy in prostate cancer.

Experimental Validation of the Eclipse AAA Algorithm

The present study evaluates the performance of a newly released photon‐beam dose calculation algorithm that is incorporated into an established treatment planning system (TPS). We compared the analytical anisotropic algorithm (AAA) factory‐commissioned with “golden beam data” for Varian linear accelerators with measurements performed at two institutions using 6‐MV and 15‐MV beams. The TG‐53 evaluation regions and criteria were used to evaluate profiles measured in a water phantom for a wide variety of clinically relevant beam geometries. The total scatter factor (TSF) for each of these geometries was also measured and compared against the results from the AAA. At one institute, TLD measurements were performed at several points in the neck and thoracic regions of a Rando phantom; at the other institution, ion chamber measurements were performed in a CIRS inhomogeneous phantom. The phantoms were both imaged using computed tomography (CT), and the dose was calculated using the AAA at corresponding detector locations. Evaluation of measured relative dose profiles revealed that 97%, 99%, 97%, and 100% of points at one institute and 96%, 88%, 89%, and 100% of points at the other institution passed TG‐53 evaluation criteria in the outer beam, penumbra, inner beam, and buildup regions respectively. Poorer results in the inner beam regions at one institute are attributed to the mismatch of the measured profiles at shallow depths with the “golden beam data.” For validation of monitor unit (MU) calculations, the mean difference between measured and calculated TSFs was less than 0.5%; test cases involving physical wedges had, in general, differences of more than 1%. The mean difference between point measurements performed in inhomogeneous phantoms and Eclipse was 2.1% (5.3% maximum) and all differences were within TG‐53 guidelines of 7%. By intent, the methods and evaluation techniques were similar to those in a previous investigation involving another convolution–superposition photon‐beam dose calculation algorithm in another TPS, so that the current work permitted an independent comparison between the two algorithms for which results have been provided. PACS number: 87.53.Dq

Acute Toxicity in High-Risk Prostate Cancer Patients Treated With Androgen Suppression and Hypofractionated Intensity-Modulated Radiotherapy

PURPOSE To report acute toxicity resulting from radiotherapy (RT) dose escalation and hypofractionation using intensity-modulated RT (IMRT) treatment combined with androgen suppression in high-risk prostate cancer patients. METHODS AND MATERIALS Sixty patients with a histological diagnosis of high-risk prostatic adenocarcinoma (having either a clinical Stage of > or =T3a or an initial prostate-specific antigen [PSA] level of > or =20 ng/ml or a Gleason score of 8 to 10 or a combination of a PSA concentration of >15 ng/ml and a Gleason score of 7) were enrolled. RT prescription was 68 Gy in 25 fractions (2.72 Gy/fraction) over 5 weeks to the prostate and proximal seminal vesicles. The pelvic lymph nodes and distal seminal vesicles concurrently received 45 Gy in 25 fractions. The patients were treated with helical TomoTherapy-based IMRT and underwent daily megavoltage CT image-guided verification prior to each treatment. Acute toxicity scores were recorded weekly during RT and at 3 months post-RT, using Radiation Therapy Oncology Group acute toxicity scales. RESULTS All patients completed RT and follow up for 3 months. The maximum acute toxicity scores were as follows: 21 (35%) patients had Grade 2 gastrointestinal (GI) toxicity; 4 (6.67%) patients had Grade 3 genitourinary (GU) toxicity; and 30 (33.33%) patients had Grade 2 GU toxicity. These toxicity scores were reduced after RT; there were only 8 (13.6%) patients with Grade 1 GI toxicity, 11 (18.97%) with Grade 1 GU toxicity, and 5 (8.62%) with Grade 2 GU toxicity at 3 months follow up. Only the V60 to the rectum correlated with the GI toxicity. CONCLUSION Dose escalation using a hypofractionated schedule to the prostate with concurrent pelvic lymph node RT and long-term androgen suppression therapy is well tolerated acutely. Longer follow up for outcome and late toxicity is required.

A treatment planning study comparing helical tomotherapy with intensity-modulated radiotherapy for the treatment of anal cancer

PURPOSE A planning study to compare helical tomotherapy (HT) and intensity-modulated radiotherapy (IMRT) for the treatment of anal canal cancer. MATERIALS AND METHODS Sixteen (8 males and 8 females) patients with anal cancer previously treated radically were identified. HT and IMRT plans were generated and dosimetric comparisons of the plans were performed. The planning goals were to deliver 54Gy to the tumor (PTV(54Gy)) and 48Gy to the nodes at risk (PTV(Node)) in 30 fractions. RESULTS PTVs: HT plans were more homogeneous for both men and women. Male patients: HT vs. IMRT: D(max): 55.87+/-0.58 vs. 59.17+/-3.24 (p=0.036); D(min): 52.91+/-0.36 vs. 44.09+/-6.84 (p=0.012); female patients: HT vs. IMRT: D(max): 56.14+/-0.71 vs. 59.47+/-0.81 (p=0.012); D(min): 52.36+/-0.87 vs. 50.97+/-1.42 (p=0.028). OARs: In general, HT plans delivered a lower dose to the peritoneal cavity, external genitalia and the bladder and IMRT plans resulted in greater sparing of the pelvic bones (iliac crest/femur) for both men and women. Iliac crest/femur: the difference was significant only for the mean V10Gy of iliac crest in women (p< or =0.012). External genitalia: HT plans achieved better sparing in women compared to men (p< or =0.046). For men, the mean doses were 18.96+/-3.17 and 15.72+/-3.21 for the HT and IMRT plan, respectively (p< or =0.017). Skin: both techniques achieved comparable sparing of the non-target skin (p=NS). CONCLUSIONS HT and IMRT techniques achieved comparable target dose coverage and organ sparing, whereas HT plans were more homogeneous for both men and women.

An evaluation of the Clarity 3D ultrasound system for prostate localization

The purpose of this study is to evaluate the accuracy and precision of the Clarity 3D ultrasound system to track prostate gland positional variations due to setup error and organ motion. Seventeen patients (n=17) undergoing radical external beam radiation therapy for localized prostate cancer were studied. Subsequent to initial reference ultrasound and planning CT scans, each patient underwent seven repeat weekly tracking CT and ultrasound (US) scans during the course of treatment. Variations in the location of the prostate between reference and tracking scans were measured. Differences reported by CT and ultrasound scans are compared. Ultrasound tracking was initially performed clinically by a group of trained general users. Retrospective prostate localization was then performed by a trained dedicated user upon the original raw data set and also a reduced data set derived from the original by an expert user from Resonant Medical. Correlation accuracy between ultrasound and CT shifts acquired and delineated by a pool of trained general users was deemed unacceptable for radiotherapy purposes. A mean discrepancy between CT and US localizations of greater than 10 mm, with a 5 mm or greater discrepancy rate of nearly 90%, was observed. Retrospective analysis by a dedicated user of both the original and Resonant Medical reduced data sets yielded mean CT‐Us discrepancies of 8.7 mm and 7.4 mm, respectively. Unfortunately, the 5 mm or greater CT‐US discord rate for these retrospective analyses failed to drop below 80%. The greatest disparity between CT and ultrasound was consistently observed in the superior–inferior direction, while greatest agreement was achieved in the lateral dimension. Despite an expert reanalysis of the original data, the Clarity ultrasound system failed to deliver an acceptable level of geometric accuracy required for modern radiotherapy purposes. PACS numbers: 8755ne, 87.56Da, 87.63dh

Phase I study of hypofractionated intensity modulated radiation therapy with concurrent and adjuvant temozolomide in patients with glioblastoma multiforme

PurposeTo determine the safety and efficacy of hypofractionated intensity modulated radiation therapy (Hypo-IMRT) using helical tomotherapy (HT) with concurrent low dose temozolomide (TMZ) followed by adjuvant TMZ in patients with glioblastoma multiforme (GBM).Methods and materialsAdult patients with GBM and KPS > 70 were prospectively enrolled between 2005 and 2007 in this phase I study. The Fibonacci dose escalation protocol was implemented to establish a safe radiation fractionation regimen. The protocol defined radiation therapy (RT) dose level I as 54.4 Gy in 20 fractions over 4 weeks and dose level II as 60 Gy in 22 fractions over 4.5 weeks. Concurrent TMZ followed by adjuvant TMZ was given according to the Stupp regimen. The primary endpoints were feasibility and safety of Hypo-IMRT with concurrent TMZ. Secondary endpoints included progression free survival (PFS), pattern of failure, overall survival (OS) and incidence of pseudoprogression. The latter was defined as clinical or radiological suggestion of tumour progression within three months of radiation completion followed by spontaneous recovery of the patient.ResultsA total of 25 patients were prospectively enrolled with a median follow-up of 12.4 months. The median age at diagnosis was 53 years. Based on recursive partitioning analysis (RPA) criteria, 16%, 52% and 32% of the patients were RPA class III, class IV and class V, respectively. All patients completed concurrent RT and TMZ, and 19 patients (76.0%) received adjuvant TMZ. The median OS was 15.67 months (95% CI 11.56 - 20.04) and the median PFS was 6.7 months (95% CI 4.0 – 14.0). The median time between surgery and start of RT was 44 days (range of 28 to 77 days). Delaying radiation therapy by more than 6 weeks after surgery was an independent prognostic factor associated with a worse OS (4.0 vs. 16.1 months, P = 0.027). All recurrences occurred within 2 cm of the original gross tumour volume (GTV). No cases of pseudoprogression were identified in our cohort of patients. Three patients tolerated dose level I with no dose limiting toxicity and hence the remainder of the patients were treated with dose level II according to the dose escalation protocol. Grade 3–4 hematological toxicity was limited to two patients and one patient developed Grade 4 Pneumocystis jiroveci pneumonia.ConclusionHypo-IMRT using HT given with concurrent TMZ is feasible and safe. The median OS and PFS are comparable to those observed with conventional fractionation. Hypofractionated radiation therapy offers the advantage of a shorter treatment period which is imperative in this group of patients with limited life expectancy.

Combined treatment of human MCF-7 breast carcinoma with antibody, cationic lipid and hyaluronic acid using ex vivo assays.

The effective targeting of malignant cell surface antigens is essential in cancer therapy. Resistance to treatment and rapid invasion of cancer cells are the main causes of cancer mortality. Despite intense research efforts, treatments often have demonstrated insufficient outcomes in clinical applications. The aim of the present study was to determine whether combined administration of monoclonal antibody (Herceptin, trastuzumab) and anti-HER-2 (clone CB11) with hyaluronic acid (HA) and lipoplex (containing lipofectamine (LipA) and plasmid DNA) can produce a synergistic reaction to increase the therapeutic effect of monoclonal antibodies. To assess the treatment response, we cultured a 3-D MCF-7 cell line overexpressing HER-2 and CD44 receptors. The high density 3-D cell aggregation in the hollow fiber bioreactor (HFB) used for the cell culture was monitored with the use of proton magnetic resonance imaging ((1)H MRI). In addition, matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) was used in combination with HPLC (high performance liquid chromatography) to evaluate structural changes in the proteins contained in treated cells. The study showed that incorporation of antibodies into targeted lipoplex results in more efficient delivery of the complex to tumor cells. The viability of cells decreased mostly due to cellular uptake of lipoplex and binding of the antibodies to the cellular surface receptor. The data also demonstrate that HA could be used to enhance treatment efficacy of trastuzumab and anti-HER-2 (clone CB11) in breast cancer cell cultures.

Derivatives of thiocolchicine and its applications to CEM cells treatment using 19F magnetic resonance ex vivo.

It was shown, that cultured ex vivo human T-Lymphoblastoid (CEM) cells respond to synthesized thiocolchicine and fluorine thiocolchicine derivatives. The preparation of derivatives with substitution at C-3 and C-7 is described. All compounds were used at concentration from 1 nM to 1000 nM. Inhibitory effects of these compounds were examined in the three-dimensional (3-D) culture and cells morphology during treatment was monitored using 9.4 T MRI system. We performed studies of these compounds in CEM cells ex vivo using 1H and 19F Magnetic Resonance Imaging (MRI), 19F Magnetic Resonance Spectroscopy (MRS), High Performance Liquid Chromatography coupled with Ultra Violet (HPLC-UV) and Electron Impact Mass Spectrometry (EIMS). The results of the multi-technique approach are consistent with the fact that the new derivatives are more efficient than colchicine and thiocolchicine ex vivo.

The application of 19F magnetic resonance ex vivo imaging of three-dimensional cultured breast cancer cells to study the effect of δ-tocopherol

The aim of this study was to determine the role of delta-tocopherol in breast cancer cell growth ex vivo. Human gland mammary adenocarcinoma (MCF-7) and human T-lymphoblastoid (CEM) cells were cultured in the presence of delta-tocopherol at various concentrations (0-750 microM) for 5 days. We have grown 3D ex vivo breast cancer cell cultures in the hollow fiber bioreactor (HFBR). (19)F magnetic resonance imaging (MRI) was used to evaluate oxygen concentration in the cell suspension and thus its viability.

Tumour xenograft detection through quantitative analysis of the metabolic profile of urine in mice

The metabolic content of urine from NIH III nude mice (n = 22) was analysed before and after inoculation with human glioblastoma multiforme (GBM) cancer cells. An age- and gender-matched control population (n = 14) was also studied to identify non-tumour-related changes. Urine samples were collected daily for 6 weeks, beginning 1 week before cell injection. Metabolite concentrations were obtained via targeted profiling with Chenomx Suite 5.1, based on nuclear magnetic resonance (NMR) spectra acquired on an Oxford 800 MHz cold probe NMR spectrometer. The Wilcoxon rank sum test was used to evaluate the significance of the change in metabolite concentration between the two time points. Both the metabolite concentrations and the ratios of pairs of metabolites were studied. The complicated inter-relationships between metabolites were assessed through partial least-squares discriminant analysis (PLS-DA). Receiver operating characteristic (ROC) curves were generated for all variables and the area under the curve (AUC) calculated. The data indicate that the number of statistically significant changes in metabolite concentrations was more pronounced in the tumour-bearing population than in the control animals. This was also true of the ratios of pairs of metabolites. ROC analysis suggests that the ratios were better able to differentiate between the pre- and post-injection samples compared to the metabolite concentrations. PLS-DA models produced good separation between the populations and had the best AUC results (all models exceeded 0.937). These results demonstrate that metabolomics may be used as a screening tool for GBM cells grown in xenograft models in mice.