Adrienn Cserháti

Role of systemic therapy in the development of lung sequelae after conformal radiotherapy in breast cancer patients

PURPOSE To analyze the risk of radiogenic lung damage in breast cancer patients after conformal radiotherapy and different forms of systemic treatment. METHODS AND MATERIALS In 328 patients receiving sequential taxane-based chemotherapy, concomitant hormone therapy (tamoxifen or aromatase inhibitors), or no adjuvant systemic therapy, symptomatic and asymptomatic lung sequelae were prospectively evaluated via the detection of visible CT abnormalities, 3 months or 1 year after the completion of the radiotherapy. RESULTS Significant positive associations were detected between the development of both pneumonitis and fibrosis of Grade 1 and patient age, ipsilateral mean lung dose, volume of the ipsilateral lung receiving 20 Gy, and irradiation of the regional lymph nodes. In multivariate analysis, age and mean lung dose proved to be independent predictors of early (odds ratio [OR] = 1.035, 95% confidence interval [CI] 1.011-1.061 and OR = 1.113, 95% CI 1.049-1.181, respectively) and late (OR = 1.074, 95% CI 1.042-1.107 and OR = 1.207, 95% CI 1.124-1.295, respectively) radiogenic lung damage, whereas the role of systemic therapy was significant in the development of Grade 1 lung fibrosis (p = 0.01). Among the various forms of systemic therapy, tamoxifen increased the risk of late lung sequelae (OR = 2.442, 95% CI 1.120-5.326, p = 0.025). No interaction was demonstrated between the administration of systemic therapy and the other above-mentioned parameters as regards the risk of radiogenic lung damage. CONCLUSIONS Our analyses demonstrate the independent role of concomitant tamoxifen therapy in the development of radiogenic lung fibrosis but do not suggest such an effect for the other modes of systemic treatment.

Individualized positioning for maximum heart protection during breast irradiation

Abstract Background. Prone positioning has been found feasible and appropriate for the reduction of radiation exposure of the lungs, but its effects on the heart dose remain controversial. Individual anatomical features were sought for the selection of optimal treatment positioning. Material and methods. In 138 left-sided breast cancer cases awaiting postoperative whole-breast radiotherapy, conformal radiotherapy plans were generated in both prone and supine positions. Results. The radiation doses to the left anterior descending coronary artery (LAD) and heart in the two positions differed individually, and were strongly related to the body mass index (BMI). Image fusion of the CT scans revealed that prone positioning was detrimental if the heart was situated distant from the chest wall in the supine position, but moved to the chest wall in the prone position. For characterization of the geography of the heart and the breast, the median distance between the LAD and the chest wall (dmedian), and the heart area included in the radiation field on a single CT scan at the middle of the heart in the supine position (Aheart) proved most appropriate. Conclusion. A validated statistical model, utilizing the BMI, dmedian and Aheart, permits individualized positioning for maximum heart protection.

A prospective study of supine versus prone positioning and whole-body thermoplastic mask fixation for craniospinal radiotherapy in adult patients

PURPOSE To evaluate neuroaxis irradiation for adults in the supine position using head body thermoplastic mask fixation, from the aspects of dose distribution, patient comfort and set-up accuracy. METHODS AND MATERIALS Nine of the 12 adult patients were positioned for craniospinal axis irradiation in both prone and supine positions. After mask fixation and planning CTs in both positions, a questionnaire relating to the comfort was completed. The doses to the target and to the organs at risk of the 3D conformal plans in the supine and prone positions were compared. Portal images of all 12 patients irradiated in the supine position were evaluated, the van Herk formulas being used to calculate the systemic and random errors. RESULTS No significant difference was found between the prone and supine positions target coverage, the dose homogeneity and the dose to the organs at risk. The supine position was considered more comfortable by the patients (scores of 2.8 versus 4.29), with a vector random error of 3.27 mm, and a systematic error of 0.32 mm. The largest random set-up error was observed in the lateral direction: 4.83 mm. CONCLUSIONS The more comfortable supine position is recommended for craniospinal irradiation in adult patients. Whole-body thermoplastic mask immobilization provides excellent repositioning accuracy.

Radiation dose to the nodal regions during prone versus supine breast irradiation

Background Prone positioning for breast radiotherapy is preferable when the aim is a reduction of the dose to the ipsilateral lung or the heart in certain left-sided cases. Materials and methods In 100 breast cancer cases awaiting postoperative whole-breast radiotherapy, conformal radiotherapy plans were prospectively generated in both prone and supine positions. The axillary nodal region (levels I–III) and internal mammary (IM) lymph-node region in the upper three intercostal spaces were retrospectively contoured. The mean doses to the nodal regions and the volume receiving 25 Gy (V25Gy), V45Gy, and V47.5Gy were compared between the two treatment positions. Results In most cases, the doses to axillary levels I–III and the IM lymph nodes were inadequate, regardless of the treatment position. The nodal doses were significantly lower in the prone than in the supine position. The radiation doses to levels II–III and IM nodes were especially low. The V45Gy and V47.5Gy of the level I axillary lymph nodes were 54.6% and 40.2%, respectively, in the supine, and 3.0% and 1.7%, respectively, in the prone position. In the supine position, only 17 patients (17%) received a mean dose of 45 Gy to the axillary level I nodes. Conclusion The radiation dose to the axillary and IM lymph nodes during breast radiotherapy is therapeutically insufficient in most cases, and is significantly lower in the prone position than in the supine position.

Broken venous catheter straddling in the pulmonary artery

The 49-year old male patient received eight cycles of adjuvant XELOX chemotherapy after the removal of a colon cancer of stage Dukes C. At the beginning of the oncological therapy, a portacath was implanted with the aim of easy vein access. Four years after the termination of the chemotherapy, routine CT showed that the tube of the portacath was missing at the reservoir side, but a 10 cm long catheter was drifted in the 2 branches of the pulmonary artery at the bifurcation. By retrospective viewing, the catheter suffered refraction during the follow-up period, and remained so for 1.5 years before detection. Vigilance should be practiced for the appropriate follow-up or the removal of the port when it is no longer needed.