Description: Available online 20 December 2012 Publication year: 2012 Source: Radiotherapy and Oncology Purpose To present a new method that assesses the delivered maximum dose of different spinal cord sections in head-and-neck cancer treated with intensity-modulated radiation therapy (IMRT). This allows a more accurate estimation of the remaining cord dose tolerance in case of a later re-irradiation treatment planning. Materials and methods The suggested workflow is demonstrated using daily acquired kilo-voltage control-CTs of four head-and-neck cancer patients (118 control-CTs). The local maximum dose inside different cord levels is determined and accumulated for the planning situation and over the treatment course for an IGRT and a non-IGRT approach. Results The approach is suitable to accurately detect and document the delivered maximum dose dependent on the cord levels. The delivered maximum dose differed up to 13% from the planned one in all sections due to setup uncertainties and the applied correction strategy. Conclusion The presented approach facilitates later re-irradiation treatment planning due to detailed documentation of the delivered maximum dose to the spinal cord levels in the primary IMRT. The method also facilitates the interpretation of complex 3D dose information by reducing it to its essentials. This 2D illustration is an aid to orientation for the physician in the re-irradiation planning process.

Description: December 2012 Publication year: 2012 Source: Radiotherapy and Oncology, Volume 105, Issue 3 The field of radiogenomics has evolved substantially over the last few years. Cooperative research groups have been established and high throughput genotyping has become increasingly feasible and affordable. Nevertheless, a number of clinical and dosimetric issues need to be carefully considered in order to fully exploit these new possibilities.

Description: December 2012 Publication year: 2012 Source: Radiotherapy and Oncology, Volume 105, Issue 3 Background and purpose Radiotherapy of thoracic and chest-wall tumors increases the long-term risk of radiation-induced heart disease, like a myocardial infarct. Cancer patients commonly have additional risk factors for cardiovascular disease, such as hypercholesterolemia. The goal of this study is to define the interaction of irradiation with such cardiovascular risk factors in radiation-induced damage to the heart and coronary arteries. Material and methods Hypercholesterolemic and atherosclerosis-prone ApoE −/− mice received local heart irradiation with a single dose of 0, 2, 8 or 16 Gy. Histopathological changes, microvascular damage and functional alterations were assessed after 20 and 40 weeks. Results Inflammatory cells were significantly increased in the left ventricular myocardium at 20 and 40 weeks after 8 and 16 Gy. Microvascular density decreased at both follow-up time-points after 8 and 16 Gy. Remaining vessels had decreased alkaline phosphatase activity (2–16 Gy) and increased von Willebrand Factor expression (16 Gy), indicative of endothelial cell damage. The endocardium was extensively damaged after 16 Gy, with foam cell accumulations at 20 weeks, and fibrosis and protein leakage at 40 weeks. Despite an accelerated coronary atherosclerotic lesion development at 20 weeks after 16 Gy, gated SPECT and ultrasound measurements showed only minor changes in functional cardiac parameters at 20 weeks. Conclusions The combination of hypercholesterolemia and local cardiac irradiation induced an inflammatory response, microvascular and endocardial damage, and accelerated the development of coronary atherosclerosis. Despite these pronounced effects, cardiac function of ApoE −/− mice was maintained.

Description: December 2012 Publication year: 2012 Source: Radiotherapy and Oncology, Volume 105, Issue 3 Purpose Our previous study reveals bone marrow transplantation (BMT) recruits host marrow-derived myelomonocytic cells to radiation-injured intestine, enhancing stromal proliferation, leading secondarily to epithelial regeneration. In this study, we propose BMT ameliorates intestinal damage via paracrine mechanisms. Materials and methods Angiogenic cytokines within the intestinal mucosa of mice after whole body irradiation (WBI) with or without BMT were measured by cytokine array and ELISA. BM conditioned medium (BMCM) with or without treatment with neutralizing antibodies to angiogenic cytokines were continuously infused into mice for three days after radiation. Carrageenan was used to deplete myelomonocytic cells of mice. Results BMT increased VEGF, bFGF and other angiogenic and chemotactic cytokines in the intestinal mucosa within 24 h after WBI. Infusion of BMCM ameliorated radiation-induced intestinal damage with improved stromal activity and prolonged survival of mice. Neutralization of bFGF, PDGF and other angiogenic cytokines within BMCM abolished the mitigating effect to the intestine. Pretreatment of carrageenan to recipient mice reversed some of the cytokine levels, including VEGF, bFGF and IGF within the intestinal mucosa after BMT. Conclusions Our result suggests BMT recruits host myelomonocytic cells and enhances intestinal stroma proliferation after radiation by secreting cytokines enhancing angiogenesis and chemotaxis. Host myelomonocytic cells further uplift the paracrine effect to enhance intestinal mucosal recovery.

Description: December 2012 Publication year: 2012 Source: Radiotherapy and Oncology, Volume 105, Issue 3

Description: Available online 28 November 2012 Publication year: 2012 Source: Radiotherapy and Oncology Background and purpose Characterization of radiotherapy activity and its trend over time. Gathering of parameters for future planning of our resources, applicable to similar population areas. Performing a clinical audit of appropriate use of radiotherapy. Material and methods Analysis of 9782 patients treated between 1998 and 2008. Descriptive statistics of pathologies and social/demographic characteristics. Intention of treatment. The rate of radiotherapy utilization was estimated and compared with those considered optimal. Rate of reirradiation. Results The average global rate of radiotherapy utilization for the period was 32.7%. It increased by 23% between 1998 and 2008, while the population of the area rose by 1.04%, equaling an average 1.13 irradiations/1000 inhabitants/year. Radiation treatment has increased by 13.6, 2.3, 1.6 and 1.06 times in patients with prostate, breast, rectal and lung cancer, respectively. Eight percent of radiotherapy treatments involve concurrent chemotherapy. The proportion of treatments with palliative intent was 18.2%. The overall underutilization of radiation therapy in our environment was an estimated 13.4%. Conclusions The grade of adequacy of radiation rates in relation with scientific evidence was globally considered suboptimal, especially in lung cancer. There was an upward trend of irradiation in breast and prostate cancer, tending toward rates considered optimal.

Description: Available online 27 November 2012 Publication year: 2012 Source: Radiotherapy and Oncology Purpose To investigate the pattern of lymph node spread on magnetic resonance lymphography (MRL) in prostate cancer patients and compare this pattern to the clinical target volume for elective pelvis irradiation as defined by the radiation therapy oncology group (RTOG-CTV). Methods and materials The charts of 60 intermediate and high risk prostate cancer patients with non-enlarged positive lymph nodes on MRL were reviewed. Positive lymph nodes were assigned to a lymph node region according to the guidelines for delineation of the RTOG-CTV. Five lymph node regions outside this RTOG-CTV were defined: the para-aortal, proximal common iliac, pararectal, paravesical and inguinal region. Results Fifty-three percent of the patients had an MRL-positive lymph node in a lymph node region outside the RTOG-CTV. The most frequently involved aberrant sites were the proximal common iliac, the pararectal and para-aortal region, which were affected in 30%, 25% and 18% respectively. Conclusion More than half of the patients had an MRL-positive lymph node outside the RTOG-CTV. To reduce geographical miss while minimizing the toxicity of radiotherapy, image based definition of an individual target volume seems to be necessary.

Description: Available online 2 November 2012 Publication year: 2012 Source: Radiotherapy and Oncology Purpose This study quantifies pulmonary radiation toxicity in patients who received proton therapy for esophagus cancer. Materials/methods We retrospectively studied 100 esophagus cancer patients treated with proton therapy. The linearity of the enhanced FDG uptake vs. proton dose was evaluated using the Akaike Information Criterion (AIC). Pneumonitis symptoms (RP) were assessed using the Common Toxicity Criteria for Adverse Events version 4.0 (CTCAEv4). The interaction of the imaging response with dosimetric parameters and symptoms was evaluated. Results The RP scores were: 0 grade 4/5, 7 grade 3, 20 grade 2, 37 grade 1, and 36 grade 0. Each dosimetric parameter was significantly higher for the symptomatic group. The AIC winning models were 30 linear, 52 linear quadratic, and 18 linear logarithmic. There was no significant difference in the linear coefficient between models. The slope of the FDG vs. proton dose response was 0.022 for the symptomatic and 0.012 for the asymptomatic ( p = 0.014). Combining dosimetric parameters with the slope did not improve the sensitivity or accuracy in identifying symptomatic cases. Conclusions The proton radiation dose response on FDG PET/CT imaging exhibited a predominantly linear dose response on modeling. Symptomatic patients had a higher dose response slope.

Description: November 2012 Publication year: 2012 Source: Radiotherapy and Oncology, Volume 105, Issue 2 Purpose To investigate the accuracy of surface imaging for monitoring intrafraction motion purposes in frameless stereotactic body radiotherapy (SBRT) of lung cancer by comparison with cone-beam computed tomography (CBCT). Materials and methods Thirty-six patients (18 males, 18 females) were included. During each fraction, three CBCT scans were acquired; CBCT1: before treatment, CBCT2: after correction for tumor misalignment, and CBCT3: after treatment. Intrafraction motion was derived by registering CBCT2 and CBCT3 to the mid-ventilation planning CT scan. Surfaces were captured concurrently with CBCT acquisitions. Retrospectively, for each set of surfaces, an average surface was created: Surface1, Surface2, and Surface3. Subsequently, Surface3 was registered to Surface2 to assess intrafraction motion. For the differences between CBCT- and surface-imaging-derived 3D intrafraction motions, group mean, systematic error, random error and limits of agreement (LOA) were calculated. Results Group mean, systematic and random errors were smaller for females than for males: 0.4 vs. 1.3, 1.3 vs. 3.1, and 1.7 vs. 3.3 mm respectively. For female patients deviations between CBCT-tumor- and 3D-surface-imaging-derived intrafraction motions were between −3.3 and 4.3 mm (95% LOA). For male patients these were substantially larger: −5.9–9.5 mm. Conclusion Surface imaging is a promising technology for monitoring intrafraction motion purposes in SBRT for female patients.

Description: November 2012 Publication year: 2012 Source: Radiotherapy and Oncology, Volume 105, Issue 2 Purpose To assess the clinical relevance of a semiautomatic CT-based ensemble segmentation method, by comparing it to pathology and to CT/PET manual delineations by five independent radiation oncologists in non-small cell lung cancer (NSCLC). Materials and methods For 20 NSCLC patients (stages Ib–IIIb) the primary tumor was delineated manually on CT/PET scans by five independent radiation oncologists and segmented using a CT based semi-automatic tool. Tumor volume and overlap fractions between manual and semiautomatic-segmented volumes were compared. All measurements were correlated with the maximal diameter on macroscopic examination of the surgical specimen. Imaging data are available on www.cancerdata.org . Results High overlap fractions were observed between the semi-automatically segmented volumes and the intersection (92.5 ± 9.0, mean ± SD) and union (94.2 ± 6.8) of the manual delineations. No statistically significant differences in tumor volume were observed between the semiautomatic segmentation (71.4 ± 83.2 cm 3 , mean ± SD) and manual delineations (81.9 ± 94.1 cm 3 ; p = 0.57). The maximal tumor diameter of the semiautomatic-segmented tumor correlated strongly with the macroscopic diameter of the primary tumor ( r = 0.96). Conclusions Semiautomatic segmentation of the primary tumor on CT demonstrated high agreement with CT/PET manual delineations and strongly correlated with the macroscopic diameter considered as the “gold standard”. This method may be used routinely in clinical practice and could be employed as a starting point for treatment planning, target definition in multi-center clinical trials or for high throughput data mining research. This method is particularly suitable for peripherally located tumors.