The Impact Of Radiotherapy On Cosmetic Results And Dose Distribution After Immediate Breast Reconstruction

Objective:1To observe breast cosmetic results of short-term andlong-term differences in patients with or without radiotherapy after immediatebreast reconstruction.2To study the dose distribution of organs at risk (OAR)in patients with immediate breast reconstruction.Methods: Between February2007to July2012,54breast cancer patientswere enrolled into this study. They all received breast reconstruction aftermastectomy at the Fourth Hospital, Hebei Medical University, of which22patients received postoperative radiotherapy. All the patients met the followingcriteria:(1) Female;(2) Immediate breast reconstruction (dilator implantation)/(silica gel prosthesis implantation) after mastectomy at the Fourth Hospital,Hebei Medical University;(3) Pathologically confirmed cancer;(4) Thehistory of receiving neoadjuvant chemotherapy or chemotherapy;(5) Patientswith stable mental state had breast reconstruction requirements and fullyunderstood practical consequences of reconstructive surgery. According toreceiving adjuvant postoperative radiotherapy or not, the patients were dividedinto two groups: Radiotherapy group (22cases) and non-radiotherapy group(32cases). In the radiotherapy group, three-dimensional conformalradiotherapy (3DCRT) or intensity modulated radiotherapy (IMRT) was givenafter mastectomy and immediate breast reconstruction (dilator implantation)and in the non-radiotherapy group; no radiotherapy was given aftermastectomy and immediate breast reconstruction (dilator implantation or silicagel prosthesis implantation). In the radiotherapy group,15patients weretreated with3DCRT and7patients with IMRT. All radiotherapy patients werepositioned on a customized supine breast board and received computedtomography (CT) simulation. The clinical target volume (CTV) included thewhole reconstruction breasts、chest wall and supraclavicular region and not the pectoralis major and ribs. The OARs such as heart, liver, lung and thecontralateral breast were outlined at the same time. The dose of4500-5040cGy/23-25was given to the target. The cosmetic results of thereconstruction breast were compared and evaluated between the two groups.2.The dose distribution of ipsilateral lung, heart and contralateral breast weredescribed in the22patients with radiotherapy.Results:(1) The median age was38years (range21-50). Primary tumorlocated on left breast in32patients and right side22patients. There were17patients in stage I,31patients in stage II and6patients in stage Ⅲ.(2) In theradiotherapy group, the Cosmetic result was excellent in11cases (50%), goodin7cases (31.8%), common in2cases (9.1%), poor in2cases (9.1%)respectively; and in the non-radiotherapy group, it was excellent in21cases(65.6%), good in6cases (18.8%), common in3cases (9.4%),2cases(6.3%)respectively. No significant difference was found between the twogroups (P=0.313).(3) Analysis of possible related factors on cosmetic results:1) Age: The patients were divided into two groups of no older than35or olderthan35years. There was significant difference in the cosmetic effect betweenthe two groups (P=0.017)， which was better in the yonger group.2)Chemotherapy with or without paclitaxel before radiotherapy: no significantdifference was found between the two groups for cosmetic effect,(P=0.550).3)Radiotherapy technique: The cosmetic result was excellent or good in11patients (73.3%) for the15patients with3DCRT and100%for the7patientswith IMRT, which was better for IMRT than3DCRT.4) The interval betweensurgery and radiotherapy: The median interval was5.5months (1.5-7.5months), and13patients started radiotherapy more than5months after surgery.There was no statistical significance in the cosmetic results between the twogroups (P=0.601).5) Preservation of nipple and areola: Seven patients werewith the preservation of nipple and areola, and15patients without. There wasno statistical significance in the cosmetic results between the two groups(P=0.378).(4) The overall median follow-up time was21months (1-43months). All patients were alive to the last follow-up day except that one patient died of rectal cancer. Two patients had distant metastsis in theradiotherapy group and4patients had failures in the non-radiotherapy group(2with local recurrence and2with distant metastasis). No significantdifference was found between two groups in progression-free survival (P=0.676).2Radiotherapy dose distribution of OARs：The mean dose andmaximum dose of ipsilateral lung were1179.5cGy and1884.2cGyrespectively for all22patients with radiotherapy. The mean and maximumminimum V5were48.2%and83.5%respectively;48.2%and74.4%for V20;15.2%and31.8%for V30of ipsilateral lung respectively. The mean value andmaximum value of V1for contralateral breast were46.5%and94.0%respectively;11.2%and57.7%respectively for V5of contralateral breast.There were14patients with left-sided breast cancer. The mean dose andmaximum dose of the heart were861.9cGy and1527.0cGy respectively. Andthe mean value and maximum value were7.5%and31.8%respectively forV30of the heart.Conclusions:1The radiotherapy has no significant impact on cosmetic results forbreast cancer patients after immediate breast reconstruction. Radiotherapyafter immediate breast reconstruction had no significant effect for skin andprosthesis, and they have similar cosmetic results with not radiotherapy group.And radiotherapy can reduce failures of breast cancer patients aftermastectomy and breast reconstruction.2The interval between surgery and radiotherapy, chemotherapy withpaclitaxel, preservation of nipple and areola has no significant association withthe cosmetic results after radiotherapy. Age more than35and IMRT conferbetter cosmetic effect than younger patients and3DCRT respectively.3The ipsilateral lung, contralateral breast and heart will be irradiated incertain dose and volume.