Postmastectomy Patients Research Articles

Immediate Breast Cancer Reconstruction with or without Dermal Matrix or Synthetic Mesh Support: A Review and Network Meta-Analysis.

The use of acellular dermal matrices (ADMs) and synthetic mesh as part of implant-based breast reconstruction (IBBR) has been widely adopted. The authors investigated the clinical efficacy and safety of human ADM (HADM), xenograft ADM (XADM), and synthetic mesh as part of IBBR in postmastectomy patients as compared with previous standard implant reconstruction techniques using only a submuscular pocket for coverage. A systematic search for randomized controlled trials and observational studies was performed. A frequentist network meta-analysis was conducted using the R packages netmeta and Shiny. Thirty-one of 2375 studies identified met the predefined inclusion criteria. Traditional submuscular placement (no ADM or mesh) had fewer overall complications compared with HADM [OR, 0.51; credible interval (CrI), 0.34 to 0.74], but there was no significant difference between no ADM or mesh and XADM (OR, 0.63; CrI, 0.29 to 1.32) or synthetic mesh (OR, 0.77; CrI, 0.44 to 1.30). No one treatment was superior with regards to implant loss. No ADM or mesh was associated with fewer infectious complications than HADM (OR, 0.6; CrI, 0.39 to 0.89). Both no ADM or mesh (OR, 0.45; CrI, 0.27 to 0.75) and XADM (OR, 0.46; CrI, 0.23 to 0.88) had reduced seroma compared with HADM. Selecting the appropriate IBBR should evaluate effectiveness, adverse events, and cost. Although it is difficult to select a universal ideal IBBR, evaluation using this network analysis may help guide both physicians and patients in their choice of procedure, especially in the case of HADM, which in this study was shown to be significantly predisposed to complications of infection and seroma. Randomized data are required comparing XADM versus synthetic meshes, given the similar risk profiles but significant cost discrepancy between the techniques.

Comparison of the Thermal Reaction of Patients after Conserving Procedures and after Mastectomy to the Radiation Dose Obtained during Radiotherapy

The main aim of the study was to compare the temperature response of the body to the dose received during breast cancer radiotherapy. The control group consisted of 50 healthy volunteers. They underwent one thermographic examination and compared the temperatures between the left and right breasts. The research group consisted of 50 patients. Based on the treatment plan, the area PTV and isodose was marked on the thermograms. Five thermographs were performed in each patient (before radiotherapy and in each week of treatment). A qualitatively similar increase in mean temperature during treatment was observed in both subgroups in the analyzed areas. The highest increase in temperature was obtained in the third week of treatment. Compared with the value before treatment, the increase in the mean temperature in PTV in patients after partial surgery was 0.78 °C, these values are statistically significant p = 0.000055. In the case of post-mastectomy patients, 0.8 °C was obtained, these values are statistically significant p = 0.00369. In addition, strong correlation was calculated between isodoses read from treatment plans and isotherms obtained from the analysis of thermal images. In post-mastectomy patients for PTV r = 0.77, 30 Gy r = 0.94, 20 Gy r = 0.96, and 10 Gy r = 0.75. For patients after partial surgery for PTV r = 0.74, 30 Gy r = 0.89, 20 Gy r = 0.83, and 10 Gy r = 0.89. Infrared thermography seems to be a useful method of assessing the thermal response of the body to the dose received during radiotherapy of breast cancer and may be a clinically useful method of assessing the early skin response to radiation.

Patients with Shoulder Dysfunction After Mastectomy Can Benefit from Nurse-Assisted Home-Based Range of Motion Exercises

Background: Shoulder dysfunction is very common after mastectomy, and there is also less follow-up for physiotherapy services among patients with mastectomy. Objective: A study was conducted to determine the role of nurse-assisted home-based range of motion (ROM) exercises in patients with shoulder dysfunction after mastectomy. Methods: A pre- and post-interventional study design was used to collect data from 30 post-mastectomy patients. The subjects were selected on a voluntary basis. Informed consent was obtained from post-mastectomy patients who were discharged from different oncology hospitals in Pakistan prior to their inclusion in this study. After obtaining a baseline measurement, the patients were supervised with nurse-assisted ROM exercises at home. The nurse-assisted home-based ROM exercise program was designed for such patients, and the patients were followed-up for up to 1 month. The total duration of the study was 1 year from August 2015 to August 2016. Post-intervention measurement was performed at the patients’ home. The difference in terms of pain reduction and ROM improvement at the shoulder joint was recorded using goniometric measurements and the 100 mm visual analogue scale (VAS). Results: The mean age of the 30 subjects was 39.83 ± 5.89. The mean ROM of shoulder flexion before the exercise program was 106.03°, which improved to 133.93° after 1 month of the exercise program. The mean ROM of shoulder abduction before treatment was 94.83°, which improved to 127.13° after 1 month of supervised exercise program. The mean ROM of shoulder rotation before the exercise program was 127.53°, which improved to 152.03° after 1 month of the exercise program. Conclusion: The nurse-assisted home-based shoulder ROM exercise program is effective in terms of improving the range of motion and reducing pain at the shoulder joint in post-mastectomy patients.

Adjuvant alternative cytokine-induced killer cell combined with natural killer cell immunotherapy improves the prognosis of post-mastectomy breast cancer.

Breast cancer is one of the most common cancers in women. Triple-negative breast cancer (TNBC) has a significantly worse prognosis due to the lack of endocrine receptors including estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). In this study, we investigated adjuvant cellular immunotherapy (CIT) in patients with post-mastectomy breast cancer. We enrolled 214 post-mastectomy breast cancer patients, including 107 patients in the control group (who received chemotherapy/radiotherapy/endocrine therapy) and the other 107 patients in the CIT group (who received chemotherapy/radiotherapy/endocrine therapy and subsequent immune cell infusion). Of these 214 patients, 54 had TNBC, including 26 patients in the control group and 28 patients in the CIT group. Survival analysis showed that the overall survival rate of patients treated with cellular immunotherapy was higher than that of patients who were not treated with CIT. Compared to those who received cytokine-induced killer (CIK) cells alone, the patients who received CIK combined with natural killer (NK) cell immunotherapy showed the best overall survival rate. In subgroup analyses, adjuvant CIT significantly improved the overall survival of patients in the TNBC subgroup and the patients who were aged over 50 years. Our study indicates that adjuvant CIK cell combined with NK cell treatment is an effective therapeutic strategy to prolong the survival of post-mastectomy patients, particularly for TNBC patients and those who are aged over 50 years.

Dosimetric Influence of Normalization Points on Post Mastectomy Chest Wall Teletherapy

Background: Many advanced radiotherapy techniques had been employed in breast cancer teletherapy, purposely to significantly reduce dose to organs at risk (heart and lungs) with marginal or no compromise in planning target volume (PTV). Majority of used techniques yielded rewarding results in developed countries where facilities, manpower and skills are available. In Nigeria, significant number of post mastectomy breast cancer patients received chest wall irradiation using manual hand planning, therefore, the dose distributions to target volume and organs at risk (OAR) were uncertain. Sokoto centre being the first in the country to use treatment planning system (TPS) focused on identifying planning skills (normalization points) with good 95% dose coverage to PTV, and minimizing dose to OAR. Methods: Eighteen post mastectomy patients (ten rights and eight lefts chest walls) were simulated via computed tomography scan (CT-scan) in supine position with breast board and fudicial markers to demarcate tumour bed borders. Planning target volume (PTV chest walls) and OAR were contoured from the acquired CT images and bi-tangential portals were applied. The energy used from Elekta précised Linac was 6 MV, and dose of 50Gy in 25# was prescribed to each patient. The Upper 1/3rd normalization point (UNP), Lower 1/3rd (LNP) and Inter-field (INP) were sequentially applied as dose normalization points on each planning CT image, dose to PTV and OAR were evaluated using Clarkson and pencil beam calculation algorithms. Statistical analysis was conducted using SPSS Software to study dose distributions of the normalization points. Results: Patients simulated were between the ages of 29-56yrs with mean age of 42yrs. The mean percentage doses from normalization points on left chest walls ranged between 81.7-107.7% to PTV, 13.3-17.8% to the lung and 5.5-6.8% to the heart, the reported hot spots were between 110.7 to 141.5%. Similarly, the mean doses from normalization points on the right chest walls ranged between 81.5-108.8% for PTV, 17.8-23.5% to the lung and 2.7-3.7% to the heart, with hot spots of 108.8-137.9%. The statistical differences using independent-t- test for the normalization points on both left and right chest walls shows p-value < 5%. Conclusion: The three normalization points influenced dose distribution to PTV and OAR differently. The UNP and LNP showed a desired dosimetry with marginal compromise in 95% PTV coverage compared to INP.

Target volume coverage in clinically designed radiotherapy plan of post-mastectomy adjuvant radiotherapy of breast cancer patients in comparison with radiation therapy oncology group-based contoured plan: A dosimetric study.

Conventional field radiotherapy based on anatomical landmarks has been the traditional treatment for breast cancer. Having proven efficacy, it is still the current standard of treatment. The Radiation Therapy Oncology Group (RTOG) has published guidelines for contouring target volumes in postmastectomy patients. The impact of this guideline in the current clinical practice is less known; hence, we have analyzed dose-volume histograms (DVHs) for these plans and compared them with the proposed treatment plans to treat RTOG-defined targets. RTOG consensus definitions were used to contour the target volumes in 20 previously treated postmastectomy patients. The prescription was 42.4 Gy in 16 fractions. DVHs were generated from clinically designed plans that had actually been delivered to each patient. For comparing dose to target volumes, new plans were generated with the goal of covering 95% of volume to 90% of prescribed dose. In RTOG contoured Group, coverage improved for the supraclavicular (V90 = 83 vs. 94.9%, P < 0.05) and chest wall (V90 = 89.8 vs. 95.2%, P < 0.05). Axillary nodal coverage improved for Level-1(V90 = 80.35 vs. 96.40%, P < 0.05), Level-II (V90 = 85.93 vs. 97.09%, P < 0.05) and Level III (V90 = 86.67 vs. 98.6%, P < 0.05). The dose to the ipsilateral lung is increased (V20 = 23.87 vs. 28.73%, P < 0.05). Low dose to heart is increased in left-sided cases (V5 = 14.52 vs. 16.72%, P < 0.05) while same in right-sided cases. The study shows that radiotherapy using the RTOG consensus guidelines improves coverage to target volumes with a nonsignificant increase in normal organ dose compared to that based on anatomical landmarks.

Nursing Implementation of Acute Pain Management in Post Mastectomy Surgery Patients

Background: Surgery is a potential or actual threat to a person's integrity, both biopsychosocial and spiritual. One of the treatments for breast cancer is surgery, either tumor removal or mastectomy. The problem that often arises in postoperative patients is pain, which can affect the patient's overall condition. Purpose: The purpose of this study was to determine the effect of pain management with deep breath relaxation therapy on the post operative mammae pain scale. Methods: This case study design uses a descriptive method. The sampling method used was purposive sampling with 2 respondents, namely post-mastectomy patients in the Surgical Room of Muhammadiyah Hospital Palembang, in March 2022. The case study data were taken using interviews, observations and physical examinations carried out descriptively and presented in a narrative manner Results: After implementing acute post-mastectomy pain management with deep breathing relaxation therapy in both case study subjects for 3 days there was a 3 point reduction in pain scale, in patient 1 from pain scale 6 to pain scale 3, in patient 2 from pain scale 5 to a pain scale of 2, and both case study subjects were able to move and fulfill basic needs independently. Conclusion: Acute pain management with deep breathing relaxation therapy can reduce pain scale and help patients move quickly.

Risk Factors and Complications of Abdominally Based Breast Reconstruction: A Comparative Analysis of 13,587 Patients

INTRODUCTION: Autologous breast reconstruction is most commonly abdominally based. Deep inferior epigastric perforator (DIEP), pedicled transverse rectus abdominis musculocutaneous (pTRAM), and free transverse rectus abdominus musculocutaneous (fTRAM) flaps subject a patient to significant abdominal wall morbidity. A comparative analysis of DIEP, pTRAM, and fTRAM flaps for breast reconstructions is necessary to understand major risk factors for adverse outcomes. The purpose of this study is to determine the safety and advantages of a DIEP vs pedicled TRAM vs fTRAM flap for breast reconstruction. METHODS: Admitted patients with a DIEP or pTRAM or fTRAM breast flap were analyzed using the National Inpatient Sample database, 2005–2014. Demographics, clinical data, and outcomes were collected. The relationship between mortality and predictors was assessed using a stratified analysis and multivariable logistic regression model. RESULTS: A total of 13,587 patients with DIEP, fTRAM, or pTRAM breast flap reconstruction were analyzed. Patients with a fTRAM were the most likely to experience a complication, followed by DIEP and then pTRAM. The most common complication for all groups was hemorrhage, most common in DIEP flaps. However, DIEP flap reconstructions were performed with shorter hospital stays. This group also exhibited the highest rates of thrombosis compared with pTRAM and fTRAM flaps. Conversely, the DIEP group had the lowest rates of postoperative infections, dehiscence, and pulmonary embolism. There were no significant differences in flap type used in the breast reconstruction between survived and deceased patients. CONCLUSION: These data support the DIEP flap as the chosen flap for autologous breast reconstruction in postmastectomy patients.

Association of 21-gene recurrence score and locoregional recurrence in early breast cancer patients.

The 21-gene recurrence score (RS) assay has been validated to predict the risk of disease-free survival in estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative early breast cancer patients. However, its relation with locoregional recurrence (LRR) risk is unclear. This study aimed to explore the ability of RS to predict LRR risk. Consecutive ER-positive, HER2-negative, pT1, pN0-1, and M0 early breast cancer patients were analyzed retrospectively. According to RS, patients were divided into low- (RS < 18), intermediate- (RS 18-30), and high-risk (RS ⩾ 31) groups. The primary endpoint was LRR. Subgroup analysis was conducted according to different nodal statuses and surgery types. A total of 1558 patients were enrolled: 354 (22.7%), 788 (50.6%), and 416 (26.7%) patients in the low-, intermediate-, and high-risk groups, respectively. The median follow-up time was 53 months, and 2, 8, and 14 LRR events were observed in the low-, intermediate-, and high-risk groups, respectively (P= 0.004). Both univariate (P= 0.009) and multivariate (P= 0.010) analyses demonstrated that 21-gene RS was correlated with LRR. Compared to low-risk patients, high-risk patients were at greater risk of LRR (HR 5.75, 95% CI 1.30-25.31, P= 0.021). Among pN0 (P= 0.033), pN1 (P= 0.049) and postmastectomy patients (P= 0.012), 21-gene RS remained predictive of the risk of LRR. The 21-gene RS assay was significantly associated with the risk of LRR in ER-positive, HER2-negative early breast cancer patients. Among patients with different nodal statuses and patients receiving mastectomy, RS remained predictive of the risk of LRR.

Does it Always have to be the Abdomen? Alternative Flaps in Autologous Breast Reconstruction

[English] Deep inferior epigastric artery perforator (DIEP) or muscle-sparing transverse rectus abdominis muscle (ms-TRAM) flaps remain the gold standard for autologous reconstruction in post-mastectomy patients, although many women may not be candidates for abdominally based free tissue transfer. In this scenario, there are several other donor site options based from the thigh (transverse and diagonal upper gracilis flaps, profunda artery perforator flap, lateral thigh flap), trunk (lumbar artery perforator flap), and buttock (superior and inferior gluteal artery perforator flaps). This article will provide insight into the history, relevant anatomy, surgical technique and novel applications (neurotization) for alternative flaps in autologous breast reconstruction.

Association between the cardiac contact distance and the maximum dose at the left anterior descending coronary artery in post mastectomized patients.

The clinical information on the relationship between the cardiac contact distance (CCD), the maximum dose (Dmax) delivered to the left anterior descending (LAD) coronary artery and the mean heart dose has mostly focused on patients with breast-conserving surgery (BCS), being scarce in postmastectomy patients. The aim of this study is to determine the association between the CCD and the Dmax delivered to the LAD. The secondary objective was to evaluate the dosimetric results of comparing three-dimensional conformal radiotherapy (3D-CRT) to intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) techniques for post mastectomized breast cancer patients with irradiation to the left chest wall. 53 cases of women who received adjuvant standard fractionated postmastectomy radiotherapy (PMRT) were used. Three types of plans were created for each patient: 3D-CRT, seven equidistant IMRT fields, and four partial VMAT arcs. Correlations were evaluated using Pearson's correlation coefficient. Plans made with IMRT and VMAT showed improved homogeneity and conformity. Associations between CCD and Dmax to LAD were positive for all three plan types. Compared to 3D-CRT, the modulated intensity plans obtained better dose homogeneity and conformity to the target volume. The LAD and heart doses were significantly lower for IMRT and VMAT plans. The CCD can be used as a predictor of the maximum and mean doses of the LAD. Modulated intensity techniques allow for better dose distribution and dose reduction to the heart and LAD.

Prospective study to compare the dose distribution and acute toxicity of three-dimentional conformal radiation therapy with intensity-modulated radiation therapy for post-mastectomy radiotherapy in carcinoma breast

Though adjuvant radiotherapy has an established role in the treatment of carcinoma breast, there is concern regarding irradiation to heart and lung, more on left sided disease. Intensity Modulated Radiation Therapy (IMRT) modulates the intensity of the radiation beams with better accuracy, sparing surrounding normal organs. But it increases integral dose to normal healthy tissues compared to 3-Dimensional Conformal Radiation Therapy (3DCRT). So, our study was aimed at comparing the dosimetry and acute toxicity profile of 3DCRT and IMRT in post-mastectomy patients. In study arm patients received radiotherapy with IMRT and in control arm with 3DCRT, radiation dose being 50 Gy in 25 fractions for 5 weeks for both the arms. We compared the dosimetric data for Planning Target Volume (PTV) and Organ At-risk (OAR) by both techniques along with acute toxicity profile. Dosimetric parameter of PTV coverage V95 and V107 were significantly better in IMRT than 3DCRT (p-value &lt;0.0001). IMRT showed better homogeneity index (0.14 Gy vs 0.26 Gy) and conformity index was also better for IMRT (0.94 Gy vs 0.74 Gy, p-value 0.0028). The mean value of heart V25 in left sided disease was significantly lower in IMRT than 3DCRT (22.59 and 25.64, p value 0.01). V20 of ipsilateral lung was numerically less in IMRT though not significant (31.44 vs 35.3). But low dose volume was significantly more in IMRT, as seen by higher V5 of heart and ipsilateral lung. To conclude, IMRT has better PTV coverage and better sparing of organs at risk with more homogenous and conformal plans than 3DCRT. Keywords: adjuvant radiotherapy; IMRT; 3DCRT; carcinoma breast

Mode of Detection of Second Events in Routine Surveillance of Early Stage Breast Cancer Patients

IntroductionNCCN and ASCO guidelines recommend breast cancer (BC) follow-up to include clinical breast examination (CBE) every 6 months and annual mammography (AM) for 5 years. Given limited data to support CBE, we evaluated the modes of detection (MOD) of BC-events in a contemporary practice. MethodsWe conducted a retrospective review of registry patients with early stage BC (DCIS, Stage I or II) diagnosed between 2010 and 2015 with at least 5 years of follow-up. Second events were defined as malignant (contralateral primary, ipsilateral breast tumor recurrence (IBTR), chest wall recurrence, regional node recurrence or distant relapse) or benign. MOD was categorized as patient complaint, clinical examination or breast imaging. ResultsSixty-three of 351 BC patients experienced second events. 15 had BC malignant events, including 4 distant disease, 5 contralateral primary, and 3 IBTR. 7/8 of IBTR and contralateral primary BC were AM detected. Patient complaints identified 4/4 distant relapses. Clinical exam identified 2/2 chest wall recurrences in post-mastectomy patients. ConclusionsOnly 2.8% (10/351) of early stage BC patients experienced recurrence during 5 years of follow-up. AM was the predominate MOD of both IBTR and new contralateral primary following breast conserving therapy. Patient complaints prompted evaluation for distant disease. Provider CBE was MOD in only 2/351, 0.6% 95% CI (2.1%-0.1%) of patients as chest wall recurrences postmastectomy. Given modern enhancements to imaging and lower recurrence rates, this data encourages the reassessment of guidelines for every 6-month CBE and provides basis to study telehealth in survivorship care.

Effect of Bee Venom phonophoresis on shoulder dysfunction post-mastectomy

Background: Breast cancer survivors frequently experience shoulder pain and decreased range of motion, making their daily activities more difficult. No previous studies have established the results of bee venom phonophoresis in the treatment of shoulder dysfunction post-mastectomy. Therefore, this work aimed to evaluate if bee venom phonophoresis has beneficial effects on improving the shoulder pain, dysfunction, and range of motion in post-mastectomy patients. Methods: This randomized controlled trial was carried out between November 2021 and April 2022. Forty female patients aging from 40-to 65 years suffering from shoulder dysfunction 3 to 6 months following modified radical mastectomy were randomly divided into two equal-sized groups: a study group (Group A) who received bee venom phonophoresis with pulsed ultrasound around the shoulder and a control group (Group B) who received pulsed ultrasound around the shoulder only. Three consecutive weeks of three sessions per week were devoted to the intervention program. Patients in both groups received their medical care and selected exercise program (shoulder circles figure, arm lifts figure, wand exercise figure, wall climbing&amp; corner wall stretch).

Risk Factors Associated With Postmastectomy Breast Cancer Lymphedema: A Multicenter Retrospective Analysis.

Lymphedema is an edematous condition that afflicts the postmastectomy breast cancer population, with diminished quality of life with substantial financial costs. The factors predictive of postmastectomy lymphedema development in breast cancer patients are unknown. The objective was to evaluate the trends over time in lymphedema development and the risk factors predictive of lymphedema-related events within 2 years of mastectomy. Using the New York Statewide Planning and Research Cooperative System multicenter deidentified database from 2010 to 2016, a total of 65,543 breast cancer postmastectomy female patients (mean age, 59 ± 20 years) were identified across 177 facilities. The breast cancer patients were followed for any 2-year postmastectomy lymphedema-related events. A multivariable model identified predictors of 2-year lymphedema using eligible variables involving demographics, comorbidities, and complications. Elixhauser score was defined as a comorbidity index based on International Classification of Diseases codes used in hospital settings. Overall, 5.2% (n = 3409) of the breast cancer postmastectomy patients experienced a lymphedema-related event within 2 years of initial surgery. Over time, 2-year postmastectomy lymphedema rates have more than doubled from 4.62% in 2010 to 9.75% in 2016 (P < 0.001). Two-year postmastectomy lymphedema rates varied significantly by mastectomy procedure type: 5.69% of the mastectomy-only procedures, 5.96% of the mastectomies with lymph node biopsies, and 7.83% of the mastectomies with lymph node dissections (P < 0.0001). Full mastectomies had a greater 2-year lymphedema rate of 7.31% when compared with partial mastectomies with 2.79% (P < 0.0001). The top predictive risk factors for a lymphedema-related event included higher Elixhauser score, prolonged hospitalization for mastectomy, more recent mastectomy procedure, obesity, younger age, non-Asian race, Medicaid insurance, and hypertension (all P's < 0.01). Although more recent postmastectomy lymphedema rates may not be as high as historical estimates, the 2-year postmastectomy lymphedema rates have more than doubled from 2010 to 2016 requiring further elucidation as well as continued focus on treatment. Furthermore, risk factors were identified that predispose postmastectomy breast cancer patients to developing lymphedema. Given these findings, perioperative screening seems warranted to proactively identify, educate, and monitor postmastectomy patients at greatest risk of future lymphedema development.

Localization of Chronic Pain in Postmastectomy Patients: A Prospective Comparison Between Patients With and Without Breast Reconstruction.

After breast surgery with or without immediate reconstruction, chronic pain can be a major problem for patients. However, few studies have examined the details of the sites of long-lasting postoperative pain. In this study, we specified the postoperative pain location after breast surgery, including reconstruction, to find ways to improve surgical procedures or provide effective pain relief. The subjects were 205 Japanese women undergoing mastectomy or breast reconstruction with a tissue expander (TE)/implant or a deep inferior epigastric perforator (DIEP) flap. Patients were asked whether they had pain in different parts of the body at 1 year after surgery. Differences were assessed by cross-tabulation and χ2 statistics. Surveys were completed by 157 subjects. Deep inferior epigastric perforator flap cases had significantly more pain and TE/Imp cases had significantly less pain in the medial breast, upper breast, breast upper medial quadrant, and abdomen (P = 0.006, P = 0.006, P < 0.001, P < 0.001, respectively). In the neck area, pain in TE/Imp cases was significantly worse than that in all other patients (P = 0.025). There was no significant difference in chronic pain in any other body regions among the mastectomy only, TE/Imp, and DIEP flap groups. The results of the present study revealed that the localization of prolonged postoperative pain after breast surgery differs depending on the surgical procedure. In DIEP flap reconstruction, there was a marked tendency for pain in the inner and upper chest and in the abdomen, whereas TE/IMP surgery resulted in pain around the neck of the affected side. These findings may help improve surgical methods and establish effective pain relief that focuses on the identified pain areas.

Artificial Intelligence-Based Automated Treatment Planning of Postmastectomy Volumetric Modulated Arc Radiotherapy.

As a useful tool, artificial intelligence has surpassed human beings in many fields. Artificial intelligence-based automated radiotherapy planning strategies have been proposed in lots of cancer sites and are the future of treatment planning. Postmastectomy radiotherapy (PMRT) decreases local recurrence probability and improves overall survival, and volumetric modulated arc therapy (VMAT) has gradually become the mainstream technique of radiotherapy. However, there are few customized effective automated treatment planning schemes for postmastectomy VMAT so far. This study investigated an artificial intelligence based automated planning using the MD Anderson Cancer Center AutoPlan (MDAP) system and Pinnacle treatment planning system (TPS), to effectively generate high-quality postmastectomy VMAT plans. In this study, 20 patients treated with PMRT were retrospectively investigated, including 10 left- and 10 right-sided postmastectomy patients. Chest wall and the supraclavicular, subclavicular, and internal mammary regions were delineated as target volume by radiation oncologists, and 50 Gy in 25 fractions was prescribed. Organs at risk including heart, spinal cord, left lung, right lung, and lungs were also contoured. All patients were planned with VMAT using 2 arcs. An optimization objective template was summarized based on the dose of clinical plans and requirements from oncologists. Several treatment planning parameters were investigated using an artificial intelligence algorithm, including collimation angle, jaw collimator mode, gantry spacing resolution (GSR), and number of start optimization times. The treatment planning parameters with the best performance or that were most preferred were applied to the automated treatment planning method. Dosimetric indexes of automated treatment plans (autoplans) and manual clinical plans were compared by the paired t-test. The jaw tracking mode, 2-degree GSR, and 3 rounds of optimization were selected in all the PMRT autoplans. Additionally, the 350- and 10-degree collimation angles were selected in the left- and right-sided PMRT autoplans, respectively. The uniformity index and conformity index of the planning target volume, mean heart dose, spinal cord D0.03cc, mean lung dose, and V5Gy and V20Gy of the lung of autoplans were significantly better compared with the manual clinical plans. An artificial intelligence-based automated treatment planning method for postmastectomy VMAT has been developed to ensure plan quality and improve clinical efficiency.

P48. A NOVEL APPROACH TO PREDICTING RISK OF NECROSIS USING CLINICAL BREAST MEASUREMENTS

PURPOSE: Skin flap necrosis after mastectomy is a common complication that increases the risk for infection and reconstructive failure. The aim of this study is to identify patients at increased risk of skin flap necrosis using pre-operative breast measurements. METHODS: A retrospective chart review of all patients undergoing immediate breast reconstruction by two surgeons between 2011 and 2021 was performed. Data was collected regarding pre-operative breast measurements such as nipple-notch (NN) distance, nipple-inframammary fold (NF) distance, chest width (CW), breast circumference (BC), and breast height (BH). These characteristics were used to estimate surface area of the breast and incidence of mastectomy skin flap necrosis was recorded. RESULTS: Over a ten-year-period, 536 women were included for a total of 902 breasts. The average age of our cohort was 50 ± 11 and average BMI was 25.9 ± 5.5. When surface area was approximated using either a cone without a base or a half ellipsoid, larger surface area was a significant risk factor for skin necrosis (p=0.027, 0.022, respectively). Larger measurements for NN, NF, CW, BC, and BH were also significant predictors of necrosis (p<0.05). CONCLUSION: Pre-operative breast measurements can be a useful adjunct for predicting skin flap necrosis in post-mastectomy patients. Patients with higher NN, NF, CW, BC, and BH measurements should be counseled that they are at higher risk of skin compromise following mastectomy.

P58. RISK OF POST MASTECTOMY LYMPHEDEMA IN AUTOLOGOUS BREAST RECONSTRUCTION: A MULTI-CENTER 10-YEAR ANALYSIS OF 9,660 PATIENTS STRATIFIED BY FLAP-TYPE AND TIMING OF RECONSTRUCTION

PURPOSE: Following mastectomy, over 20% of women experience lymphedema. Previous studies suggest a possible protective effect of breast reconstruction against lymphedema development. This study analyzes risk of developing post-mastectomy lymphedema following autologous reconstruction by flap-type and temporality using a real-time, federated electronic medical record network (TriNetX Inc, Cambridge, MA). METHODS: 85,776,922 de-identified patient records were retrospectively screened from 2006-2021. 60,157 post-mastectomy patients aged 18-99 met criteria and were allocated into paired cohorts using common procedural terminology codes. Cohorts were then compared to assess lymphedema outcomes relative to timing (immediate vs. delayed) and flap-type (DIEP/TRAM/latissimus). Paired cohorts were compared and stratified by timing of reconstruction. Outcomes were assessed following stringent balancing for age, race, radiation, chemotherapy, hormone therapy, smoking, diabetes, obesity, and axillary lymph node dissection. Post-operative lymphedema rates within 2, 5, and 10-years of mastectomy were analyzed. RESULTS: DIEP and latissimus patients demonstrated significantly decreased risk of lymphedema compared to mastectomy without reconstruction across all time points; DIEP (Risk Ratio (RR): 0.487-0.546, 95% Confidence Interval (95%CI): 0.411-0.651,p<0.001), latissimus (RR:0.567-0.638,95%CI:0.423-0.828],p<0.001). Delayed DIEP was associated with significantly reduced post-mastectomy lymphedema risk versus immediate DIEP reconstruction within 10 years (0.639-0.652[0.459-0.889], p<0.01). CONCLUSION: Our analysis examines the potential protective effect against lymphedema of various approaches to autologous breast reconstruction. Limitations include this study’s retrospective nature and reliance on medical coding. Future prospective studies are warranted to confirm whether autologous breast reconstruction, and specifically delayed DIEPs, may be protective against post-mastectomy lymphedema.

Effective Treatment of Chronic Mastectomy Pain with Intercostal Sensory Neurectomy.

Chronic postmastectomy pain affects up to 40 percent of patients and leads to diminished quality of life and increased risk of opioid dependence. The cause of this pain is incompletely understood; however, one hypothesis is that direct injury to cutaneous intercostal nerves at the time of mastectomy and/or reconstruction leads to chronic pain. As a result, proximal neurectomy of the involved sensory nerve(s) has been suggested to be effective for these patients. The purpose of this study was to determine whether chronic pain in postmastectomy patients can be diagnosed reliably in an office setting and pain reduced by intercostal sensory neurectomy. The authors performed a retrospective review of seven patients with a history of breast surgery and chronic pain who underwent intercostal neurectomy combined with muscle or dermal wrapping of the proximal end of the resected nerve. All patients were diagnosed by history and physical examination, and suspected nerves were further identified with local anesthetic nerve blocks. An average of 3.14 neurectomies were performed per patient (range, one to six). There was a significant reduction in visual analogue scale pain scores following surgery, from 9 preoperatively to 1 postoperatively (p = 0.02). Eighty-six percent of patients were pain-free or "considerably improved" at their latest follow-up appointment (average, 6.14 months). It is concluded that intercostal sensory nerve injury at the time of mastectomy and/or reconstruction can lead to chronic mastectomy pain, which can be easily diagnosed and effectively treated with intercostal neurectomy. Therapeutic, IV.