Impact of the method chosen for the analysis of recurrences after radiotherapy for head and neck cancers: volume-based, point-based and combined methods

Intensity modulated radiation therapy for head and neck is a complex technique. Inappropriate delineation and/or dose distribution can lead to recurrences. Analysis of these recurrences should lead to improve clinical practice. For several years, different methods of analysis have been described. The purpose of this review is to describe these different methods and to discuss their advantages and limitations. The first published methods used a volume-based approach studying the entire volume of recurrence according to initial target volumes, or dose distribution. The main limitation of these methods was that the volume of recurrence studied was dependent on the delay in diagnosis of that recurrence. Subsequently, other methods used point-based approaches, conceptualizing recurrence either as a spherical expansion from a core of radioresistant cells (center of mass of recurrence volume) or using a more clinical approach, taking into account tumor expansion pathways. More recently, more precise combined methods have been described, combining the different approaches. The choice of method is decisive for conclusions on the origin of recurrence.

Outcome of postmastectomy radiotherapy after primary systemic treatment in patients with clinical T1-2N1 breast cancer

PURPOSE

The role of postmastectomy radiotherapy following primary systemic treatment in patients with clinical T1-2N1 breast cancer remains a controversial issue. The purpose of this study was to evaluate the benefit of postmastectomy radiotherapy following primary systemic treatment.

PATIENTS AND METHODS

Between 2005 and 2012, in two independent institutions, female patients with T1-2N1 breast cancer receiving primary systemic treatment followed by mastectomy and lymph node dissection because bad response, then treated with or without chest wall and regional lymph node irradiation have been studied retrospectively. The patients received normofractionated radiotherapy using 3D conformal photons or electron techniques. Locoregional recurrence-free survival, distant metastasis-free survival and disease-free survival were calculated using Kaplan-Meier method. Univariate analysis of potential prognostic factors was performed using log-rank test.

RESULTS

Eighty-eight patients have been studied. Of them, 75 patients received postmastectomy radiotherapy. At surgery, 53 patients achieved ypN0. Median follow-up was 67 months. Postmastectomy radiotherapy significantly improved locoregional recurrence-free survival, with a 5-year rate of 96.9% versus 78.6% in the group that did not have postmastectomy radiotherapy. In the subgroup of 53 patients achieving ypN0, postmastectomy radiotherapy improved locoregional recurrence-free survival (a 5-year rate of 94.7% vs. 72.9%), distant metastasis-free survival (a 5-year rate of 92.8% vs. 75%) and disease-free survival (a 5-year rate of 92.9% vs. 62.5%). By univariate analysis, postmastectomy radiotherapy was the only significant prognostic factor affecting locoregional recurrence-free survival.

CONCLUSIONS

For patients with clinical T1-2N1 disease, postmastectomy radiotherapy could significantly improve locoregional recurrence-free survival after primary systemic treatment and be even more therapeutic in the subgroup of patients with good response for primary systemic treatment by improving locoregional recurrence-free, distant metastasis-free and disease-free survival. Larger prospective studies are needed to confirm our findings.

[Relapse and alteration of results in orthognathic surgery]

Orthognathic surgery is a surgical technique that provides normalization of the face and occlusion. Some malocclusions are particularly unstable, such as maxillary transversal deficits, and anterior open bite. Many factors are implicated in the stability of surgical results. Indeed, facial balance largely depends on functions that could be the cause of unstable results, despite a good anatomical correction. Breathing, swallowing, chewing disorders and more largely alteration of the functional matrix may be sources of instability. These dysfunctions are the first cause of relapse. Others constitutional factors can also be involved in relapse. Understanding oro-facial functions and rules determining cranial and maxillo-facial balance is mandatory for the surgeon to ensure a long-term stability of procedures.