E. Rivin del Campo

Comparison between the ICRU rectal point and modern volumetric parameters in brachytherapy for locally advanced cervical cancer

PURPOSE The implementation of image-guided brachytherapy in cervical cancer raises the problem of adapting the experience acquired with 2D brachytherapy to this technique. The GEC-ESTRO (Groupe européen de curiethérapie - European Society for Radiotherapy and Oncology) has recommended reporting the dose delivered to the rectum in the maximally exposed 2 cm(3) volume, but so far, the recommended dose constraints still rely on 2D data. The aim of this study was to evaluate the relationship between the doses evaluated at the ICRU rectal point and modern dosimetric parameters. MATERIAL AND METHODS For each patient, dosimetric parameters were generated prospectively at the time of dosimetry and were reported. For analysis, they were converted in 2 Gy equivalent doses using an α/β ratio of 3 with a half-time of repair of 1.5 hours. RESULTS The dosimetric data from 229 consecutive patients treated for locally advanced cervical cancer was analyzed. The mean dose calculated at ICRU point (DICRU) was 55.75 Gy ± 4.15, while it was 59.27 Gy ± 6.16 in the maximally exposed 2 cm(3) of the rectum (P=0.0003). The D2 cm(3) was higher than the DICRU in 78% of the cases. The mean difference between D2 cm(3) and DICRU was 3.53 Gy ± 4.91. This difference represented 5.41% ± 7.40 of the total dose delivered to the rectum (EBRT and BT), and 15.49% ± 24.30 of the dose delivered when considering brachytherapy alone. The two parameters were significantly correlated (P=0.000001), and related by the equation: D2 cm(3)=0.902 × DICRU + 0.984. The r(2) coefficient was 0.369. CONCLUSION In this large cohort of patients, the DICRU significantly underestimates the D2 cm(3). This difference probably results from the optimization process itself, which consists in increasing dwell times above the ICRU point in the cervix. Considering these findings, caution must be taken while implementing image-guided brachytherapy and dose escalation.

What to expect from immediate salvage hysterectomy following concomitant chemoradiation and image-guided adaptive brachytherapy in locally advanced cervical cancer.

PURPOSE Concomitant chemoradiation followed by brachytherapy is the standard treatment for locally advanced cervical cancers. The place of adjuvant hysterectomy remains unclear but tends to be limited to incomplete responses to radiotherapy or local relapse. The aim was to analyse the benefit from immediate salvage surgery following radiation therapy in incomplete responders. METHODS Among the patients with locally advanced cervical cancer treated with concomitant chemoradiation followed by 3D image-guided adaptive brachytherapy and hysterectomy, cases with genuine macroscopic remnant, defined as at least 1cm in width, were identified. Their clinical data and outcomes were retrospectively reviewed and compared to the patients treated with the same modalities. RESULTS Fifty-eight patients were included, with a median follow-up of 4.2 years. After hysterectomy, 9 patients had macroscopic residual disease, 10 microscopic and the remaining 39 patients were considered in complete histological response. The 4-year overall survival and disease-free survival rates were significantly decreased in patients with macroscopic residual disease: 50 and 51% versus 92% and 93%, respectively. Intestinal grades 3-4 toxicities were reported in 10.4% and urinary grades 3-4 in 8.6% in the whole population without distinctive histological features. Planning aims were reached in only one patient with macroscopic residuum (11.1%). In univariate analysis, overall treatment time (>55 days) and histological subtype (adenocarcinomas or adenosquamous carcinomas) appeared to be significant predictive factors for macroscopic remnant after treatment completion (P=0.021 and P=0.017, respectively). In multivariate analysis, treatment time was the only independent factor (P=0.046, odds ratio=7.0). CONCLUSIONS Although immediate salvage hysterectomy in incomplete responders provided a 4-year disease-free survival of 51%, its impact on late morbidity is significant. Efforts should focus on respect of treatment time and dose escalation. Adenocarcinoma might require higher high-risk clinical target volume planning aims.

Mise au pointRadiothérapie axillaire prophylactique des cancers du seinProphylactic axillary radiotherapy for breast cancer

Adjuvant radiotherapy, after breast conserving surgery or mastectomy for breast cancer, improves overall survival while decreasing the risk of recurrence. However, prophylactic postoperative radiotherapy of locoregional lymph nodes for breast cancer, particularly of the axillary region, is still controversial since the benefits and the risks due to axillary irradiation have not been well defined. To begin with, when performing conformal radiotherapy, volume definition is crucial for the analysis of the risk-benefit balance of any radiation treatment. Definition and contouring of the axillary lymph node region is discussed in this work, as per the recommendations of the European Society for Radiotherapy and Oncology (ESTRO). Axillary recurrences are rare, and the recent trend leads toward less aggressive surgery with regard to the axilla. In this literature review we present the data that lead us to avoid adjuvant axillary radiotherapy in pN0, pN0i+ and pN1mi patients even without axillary clearance and to perform it in some other situations. Finally, we propose an update about the potential toxicity of adjuvant axillary irradiation, which is essential for therapeutic decision-making based on current evidence, and to guide us in the evolution of our techniques and indications of axillary radiotherapy.

Radiothérapie axillaire prophylactique des cancers du sein

Adjuvant radiotherapy, after breast conserving surgery or mastectomy for breast cancer, improves overall survival while decreasing the risk of recurrence. However, prophylactic postoperative radiotherapy of locoregional lymph nodes for breast cancer, particularly of the axillary region, is still controversial since the benefits and the risks due to axillary irradiation have not been well defined. To begin with, when performing conformal radiotherapy, volume definition is crucial for the analysis of the risk-benefit balance of any radiation treatment. Definition and contouring of the axillary lymph node region is discussed in this work, as per the recommendations of the European Society for Radiotherapy and Oncology (ESTRO). Axillary recurrences are rare, and the recent trend leads toward less aggressive surgery with regard to the axilla. In this literature review we present the data that lead us to avoid adjuvant axillary radiotherapy in pN0, pN0i+ and pN1mi patients even without axillary clearance and to perform it in some other situations. Finally, we propose an update about the potential toxicity of adjuvant axillary irradiation, which is essential for therapeutic decision-making based on current evidence, and to guide us in the evolution of our techniques and indications of axillary radiotherapy.

Implementation of the global risk analysis in pulsed-dose rate brachytherapy: methods and results.

PURPOSE To report the application of the global risk analysis (GRA) in the pulsed-dose rate (PDR) brachytherapy workflow. MATERIAL AND METHODS Analyses were led by a multidisciplinary working group established within the unit with the guidance of a quality engineer. First, a mapping of hazardous situations was developed as a result of interactions between the patient workflow for a treatment using PDR brachytherapy split into 51 sub-phases with a comprehensive list of the hazards that he/she faces (44). Interactions, when relevant, were sorted by level of priority: to be treated immediately, secondarily (the group is not entitled to treat the situation), or later (safe situation). Secondly, for each high priority dangerous situation, scenarios were developed to anticipate their potential consequences. Criticality was assessed, using likelihood and severity scales and a matrix, which allocated risks into categories: acceptable (C1), tolerable under control (C2) and unacceptable (C3). Then, corrective actions were proposed and planned when relevant, after assessment of their feasibility with a scale of effort. Finally, the criticality of the scenarios was reevaluated, taking into account the implementation of these actions, leading to a residual risk mapping, which could trigger additional proposals of actions. RESULTS Two thousand one hundred and eighty-four potential interactions between the list of hazards and the workflow were analyzed. Mapping of dangerous situations identified 213 relevant interactions, from which 61 were considered with high priority. One hundred and twenty-six scenarios were generated: 68 with a low criticality (74.3%), 58 with an intermediate score (25.7%). No scenario with the highest criticality was individualized. Twenty-one corrective actions were planned. Mapping of residual risk resulted in the disappearance of most C2 risks, leaving 5 C2 scenarios (4%), for which four monitoring indicators were implemented in addition to the corrected actions decided on. CONCLUSION The implementation of the GRA appeared feasible, and led to implement 21 corrective actions, based on scenarios and not on incidents.

An uncommon cause of dysuria solved by "boom-boom" radiotherapy.

BACKGROUND Chronic lymphocytic leukaemia is a common disease affecting the hematopoietic organs. The disease remains classically indolent for years preceding a blast crisis. However, the disease can affect all parts of the body. We report here an unusual localization. CASE PRESENTATION A 72-year-old man was followed for 2 years for an indolent chronic lymphocytic leukaemia while he presented a rapidly progressive dysuria. Prostate biopsies were performed concluding to a prostate involvement by the chronic lymphocytic leukaemia. In the absence of progression according to RAI staging system and Binets classification, he was treated with local low-dose radiotherapy, twice 2 Gy, allowing for a rapid resolution of the symptoms. No systemic treatment was introduced, and 1 year after the completion of his treatment, he is still under watchful waiting strategy for his chronic lymphocytic leukaemia. CONCLUSION Low-dose radiotherapy is an underused effective strategy in indolent lymphoma. In this case, urinary symptoms from a prostate involvement were relieved non-invasively at low cost.

OC-0129: Image-guided adaptive brachytherapy in cervical cancer: towards a personalization of planning aims

not received. SP-0128 Patient reported quality of life with IGABT in cervical cancer R.A. Nout, K. Kirchheiner, K. Tanderup, J.C. Lindegaard, R. Pötter Leiden University Medical Center (LUMC), Department of Radiotherapy, Leiden, The Netherlands Comprehensive Cancer Center Medical University of Vienna/General Hospital of Vienna, Department of Radiation Oncology, Vienna, Austria Aarhus University Hospital, Department of Oncology,