Impact of the New ESTRO-ACROP Target Volume Delineation Guideline on Breast-Related Complications after Implant-Based Reconstruction and Postmastectomy Radiotherapy

PURPOSE/OBJECTIVE(S)

The European Society for Radiotherapy and Oncology Advisory Committee in Radiation Oncology Practice (ESTRO-ACROP) recently updated a new target volume delineation guideline for postmastectomy radiotherapy (PMRT) after implant-based reconstruction. This study aimed whether this change has impact on breast-related complications.

MATERIALS/METHODS

We retrospectively reviewed patients who underwent PMRT after mastectomy with tissue expander or permanent implant insertion from 2016 to 2021. In total, 412 patients were included; 277 received RT by the new ESTRO-ACROP target delineation (ESTRO-T), and 135 received RT by conventional target delineation (CONV-T). The primary endpoint was comparison between the target groups of major breast-related complication, including infection, capsular contracture, deformity and necrosis requiring re-operation or re-hospitalization during follow-up after RT or delayed implant replacement. Complications were evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0., and capsular contracture was graded by the Baker Classification.

RESULTS

The median follow-up was 29.5 months (range, 0.3-76.8). The 1-, 2-, and 3-year incidence rates of major breast-related complication were 5.7%, 10.0%, and 11.6% in the ESTRO-T group, and 8.2%, 13.8%, and 14.7% in the CONV-T groups; it did not show a difference between the groups (P = 0.55). In multivariate analyses, target delineation is not significantly associated with the major complications (hazard ratio [HR] = 0.93; P = 0.83, Table 1). There was no significant difference between the ESTRO-T and CONV-T groups in the incidence of any breast-related complications (3-year cumulative incidence, 37.3% vs. 29.4%, respectively; P = 0.28). Symptomatic RT-induced pneumonitis rates were 2.7% in the ESTRO-T group (7 patients) and 2.2% in the CONV-T group (3 patients). Only one local recurrence event occurred in the ESTRO-T group, which was within the ESTRO-target volume.

CONCLUSION

Target volume delineation according to the new ESTRO-ACROP guideline did not reduce the risk of major or any breast-related complications. As the dosimetric benefits of heart and lung have been reported, further analyses with long-term follow-up are necessary to evaluate whether it could be connected to better clinical outcomes.

Complications of distraction lengthening in the hand

This study examined the features of 16 complications from 51 distraction lengthenings in the hands of 43 patients. From 1996 to 2006, 24 metacarpals and 27 phalanges were lengthened at a rate of 0.5 and 0.25 mm/day, respectively, using a callus distraction technique. The indications were congenital (33 cases in 27 patients) and traumatic (18 cases in 16 patients) deformities. The average percentage lengthening in the phalanges and metacarpals was 62% (16 mm) and 63% (34 mm), respectively. The distraction rates in the phalanges and metacarpals were 69 and 52 days/cm, respectively. The overall complication rate was 31%. Major complications requiring secondary procedures were non-union (one case), fracture (one case), premature union (one case), angulations (two cases) and dislodgment of pins (two cases). The minor complications encountered were delayed callus formation (four cases), joint stiffness (four cases) and soft tissue thinning (one case). Traumatic deformities had more complications than the congenital ones (nine of 18 cases and seven of 33 cases, respectively). The phalanges had a higher rate of complication than the metacarpals (11 of 27 cases and four of 24 cases, respectively). Most patients with complications except for two children with dislodgment were as satisfied with the final results as those without complications. Although callus distraction in the hand requires a long treatment period and has a relatively high rate of complication, it appears to be effective in achieving adequate bone length. A high level of patient compliance and prompt management of complications by an experienced surgeon are essential for achieving good results.