Supraclavicular Nodal Irradiation Research Articles

Association of Radiation-Induced Acute Esophagitis With Dosimetric Parameters of Oesophagus in Breast Carcinoma Patients Receiving Supraclavicular Nodal Irradiation.

We conducted this investigation to ascertain the dosimetric properties such as the mean and maximum radiation dosage during radiotherapy as well as the extent of radiation exposure to the esophagus. These factors can potentially impact the development of esophagitis in breast cancer patients undergoing supraclavicular radiation. From January to June 2023, an observational study was conducted at Bangabandhu Sheikh Mujib Medical University in Bangladesh. The patients received radiation therapy (40.05 Gy in 15 parts) to the chest wall and supraclavicular node for three weeks. We were able to guess the following from the dose volume histogram (DVH) data: the length of the esophagus in the treatment area (i.e., the size of the esophagus that was visible on the planning CT scan), the maximum dose (Dmax), the mean dose (Dmean), and the volume of the 10Gy (V10Gy) and 20Gy (V20Gy) doses that were given to the esophagus. During radiotherapy, patients were checked on once a week, and the radiotherapy oncology group was used to evaluate and grade esophagitis Results: Patients with left-sided breast cancer showed a higher Dmean, Dmax, and length of the esophagus compared to those with right-sided breast cancer. Specifically, the Dmean was 6.7 (±2.1) Gy, the Dmax was 39.2 (±1.5) Gy, and the length of the esophagus was 6.1 (±1.2) Gy. Patients with left breast cancer had elevated V10Gy and V20Gy values for the esophagus, but the difference was not statistically significant. The incidence of V10Gy for right-sided breast cancer and left-sided breast cancer was 4.2% (±2.6%) and 19.8% (±9.2%), respectively. The V20Gy was 2.4% (±0.9%) for right-sided breast cancer and 13.09% (±5.0%) for left-sided breast cancer Conclusion: In conclusion, there is a strong association between the mean oesophageal dose and radiation to the left supraclavicular region following surgery in women with breast cancer and acute esophagitis. We can reduce esophageal toxicity by prescribing dose restrictions and performing precise delineation of the esophagus.

Adjuvant medial versus entire supraclavicular lymph node irradiation in high-risk early breast cancer (SUCLANODE): a protocol for a multicenter, randomized, open-label, phase 3 trial

BackgroundSupraclavicular nodal (SCL) irradiation is commonly used for patients with high-risk breast cancer after breast surgery. The Radiation Therapy Oncology Group (RTOG) and European Society for Radiotherapy and Oncology (ESTRO) breast contouring atlases delineate the medial part of the SCL region, while excluding the posterolateral part. However, recent studies have found that a substantial proportion of SCL failures are located in the posterolateral SCL region, outside of the RTOG/ESTRO-defined SCL target volumes. Consequently, many radiation oncologists advocate for enlarging the SCL irradiation target volume to include both the medial and posterolateral SCL regions. Nevertheless, it remains uncertain whether adding the posterolateral SCL irradiation improves survival outcomes for high-risk breast cancer patients.MethodsThe SUCLANODE trial is an open-label, multicenter, randomized, phase 3 trial comparing the efficacy and adverse events of medial SCL irradiation (M-SCLI group) and medial plus posterolateral SCL irradiation (entire SCL irradiation, E-SCLI group) in high-risk breast cancer patients who underwent breast conserving-surgery or mastectomy. Patients with pathological N2-3b disease following initial surgery, or clinical stage III or pathological N1-3b if receiving neoadjuvant systemic therapy, are eligible and randomly assigned (1:1) to M-SCLI group and E-SCLI group. Stratification is by chemotherapy sequence (neoadjuvant vs. adjuvant), T stage (T3-4 vs. T1-2), N stage (N1-2 vs. N3), and ER status (positive vs. negative). Other radiation volumes are identical in the two arms, including breast/chest wall, undissected axillary lymph node, and internal mammary node. Advanced intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT), or tomotherapy techniques are recommended. Both hypofractionated and conventional fractionation schedules are permitted. The primary end point is invasive disease-free survival, and secondary end points included overall survival, SCL recurrence, local-regional recurrence, distance recurrence, safety outcome, and patient-reported outcomes. The target sample size is 1650 participants.DiscussionThe results of the SUCLANODE trial will provide high-level evidence regarding whether adding posterolateral SCL irradiation to medial SCL target volume provides survival benefit in patients with high-risk breast cancer.Trial registrationClinicalTrials.gov Identifier: NCT05059379. Registered 28 September 2021, https://www.clinicaltrials.gov/ct2/show/NCT05059379.

Thyroid function post supraclavicular lymph node irradiation in patients with breast cancer

INTRODUCTION: In East Africa, the estimated incidence of breast cancer is second only to cervical cancer. Supraclavicular irradiation post-modified mastectomy is crucial to breast cancer management, as it improves local control and overall survival. However, this is associated with adverse effects, including hypothyroidism (HT), which is usually under-reported. This study aim was to evaluate radiation-induced thyroid gland functional changes following treatment of supraclavicular lymph nodes in breast cancer patients.METHODS: This was a prospective descriptive study of patients with breast cancer from May 1, 2017, to May 30, 2018. Pre and post-treatment TSH, fT4, and fT3 values were compared using a Wilcoxon signed-rank test.RESULTS: A total of 42 patients were recruited for this study, with a mean age of 55.7 years (32-71). The mean baseline TSH level was 2.90 (±6.37), with a normal range of 0.27-4.2 uIU/mL. The mean T4 and T3 level were 15.77 (±4.83), with normal ranges of 10.16-22 pmol/l for T4, and 3.46 (±6.22), with a normal range of 1.06-3.3 nmol/l for T3. A Wilcoxon signed-rank test indicated that there was a statistically significant increase in mean TSH levels over baseline when measured at three, six-, and nine-months post-treatment, with p-values of 0.0047, 0.0002, and <0.0001, respectively. In total, four patients (10%) had thyroid function tests outside the normal ranges. Zero patients developed clinical HT during the time period studied.CONCLUSION: As hypothesized, supraclavicular radiation led to subclinical HT, but the incidence of clinical HT over time remains unknown.

Radiation-induced esophagitis in patients with breast cancer receiving supraclavicular nodal irradiation: A retrospective observational study

ABSTRACT JOURNAL/crsat/04.03/02201859-202306020-00006/figure1/v/2023-08-03T140821Z/r/image-tiff Background: Radiotherapy is an important treatment modality for locally advanced breast cancer and includes irradiation of the chest wall and supraclavicular nodes, with or without the axilla. Since the esophagus is close to the supraclavicular nodes, patients may experience acute radiation esophagitis during treatment which decreases their quality of life. Objective: To identify the dosimetric parameters of the esophagus which may affect the occurrence of esophagitis in patients with breast cancer who received supraclavicular nodal irradiation. Materials and Methods: This was a single-center retrospective observational study carried out from January 2021 to June 2022 at Father Muller Medical College Hospital, Mangalore, India. We enrolled patients with histologically proven breast cancer, who had received post-mastectomy radiation to the chest wall and supraclavicular nodes to a dose of 50 Gy in 25 fractions, 2 Gy per fraction, 5 fractions per week with 6 MV photon linear accelerator by intensity modulated radiation therapy. Toxicities were recorded every week. The parameters documented included the mean esophageal dose, maximum dose to the esophagus, and length of the esophagus within the treatment area. Results: We enrolled 25 patients with infiltrating ductal carcinoma of the breast who had undergone mastectomy and received neoadjuvant or adjuvant chemotherapy. The median age was 53 years (IQR, 44.5-63.5). Esophagitis (any grade) was noted in 18 of the 25 patients (72%). Grade 2 esophagitis developed in all 6 patients (100%) who had received a mean esophageal dose >20 Gy, and in none of the 19 (0%) who received a dose <20 Gy; P < 0.001. The development of esophagitis was not significantly associated with the esophageal length included in the treating area (P = 0.62), the maximum dose to the esophagus (P = 0.09), V10 (P = 0.49), or V20 (P = 1). The esophageal mean dose (Dmean) was the sole predictive factor for the development of esophagitis; P = 0.04. Conclusion: In patients with breast cancer receiving post-mastectomy radiation to the chest wall and supraclavicular area, the mean esophageal radiation dose is the only factor that correlates with the development of esophageal toxicity. Thus, esophageal toxicity can be reduced by prescribing dose constraints to the esophagus, thereby potentially improving the quality of life of patients.

Incidence and predictive factors of radiation‐induced hypothyroidism in breast cancer patients who receive supraclavicular lymph nodes irradiation: A prospective study

AbstractPurposeThis paper aimed to assess the incidence of radiotherapy‐induced hypothyroidism (RIHT) in breast cancer patients and correlate it with different factors.MethodsPatients with nonmetastatic breast cancer who received supraclavicular lymph node irradiation as a part of adjuvant radiotherapy from October 2019 to July 2020 were recruited and followed up for 18 months. All patients underwent three‐dimensional conformal radiotherapy and underwent computed tomography simulation. The levels of serum thyroid‐stimulating hormone (TSH), free triiodothyronine and free thyroxine levels were assessed at baseline (before starting radiotherapy) and 9,12, and 18 months after radiotherapy using immunochemilluminescence. Univariate and multivariate analyses were performed to identify significant factors associated with developing hypothyroidism.ResultsTwenty patients out of 96 (20.8%) developed hypothyroidism. Baseline TSH (cutoff value >1.42 μIU/ml) was significantly correlated with hypothyroidism.ConclusionRoutine thyroid function tests assessment is recommended for all breast cancer patients at baseline and after radiotherapy.

Hypothyroidism after Modern Photon or Proton Supraclavicular Nodal Irradiation for Breast Cancer

<h3>Purpose/Objective(s)</h3> Hypothyroidism is associated with supraclavicular nodal irradiation (SNI) for breast cancer. Clinical and dosimetric characteristics affecting the risk of hypothyroidism have yet to be fully elucidated. This work sought to identify patient characteristics, technique factors, and thyroid dosimetric parameters that are associated with developing hypothyroidism in patients treated with SNI. <h3>Materials/Methods</h3> Medical records and treatment plans of 328 patients receiving postmastectomy radiotherapy including SNI at a single institution from 2015-2021 were reviewed; patients with a diagnosis of hypothyroidism or prior ipsilateral irradiation were excluded. Thyroid contours were standardized, and medial borders of SNI volume were reviewed. For patients not receiving 25 fractions, thyroid dosimetrics were normalized using biologic effective dose with an alpha/beta ratio of 3. Associations of hypothyroidism with patient/treatment characteristics (age, side, chemotherapy use, pre-SNI thyroid volume, fractionation, technique) and thyroid dosimetrics (V500, V1000, V2000, V2600, V3000, V4500 cGy) were evaluated using univariate Cox proportional hazard models. <h3>Results</h3> Forty-seven patients had a diagnosis of hypothyroidism prior to SNI, leaving 281 evaluable patients. Median patient age was 50 years, interquartile range (IQR) 42-60 years; 1% completed bilateral SNI, 53% left, 47% right; 67% received neoadjuvant chemotherapy, 33% adjuvant chemotherapy, 19% no chemotherapy; median thyroid volume was 9.7 cc, IQR 6.7-13.3 cc; 90% were prescribed 25 fractions, 10% 15 or 16 fractions; 67% underwent proton therapy, 30% 3D conformal, 3% volumetric modulated arc. At a median follow-up of 3.6 years, the cumulative incidence of hypothyroidism was 6.2% and 7.8% at 2 and 5 years, respectively. Ninety-seven (35%) of patients had completed thyroid function tests. On univariate analysis, only smaller thyroid volume was significantly associated with an increased risk of hypothyroidism (hazard ratio (HR) 0.23 per 10 cc, 95% confidence interval (CI) 0.07-0.83, p=0.02). Thyroid V500 cGy (median 57%, IQR 49-69%) approached but did not reach significance (HR 1.23 per 10%, 95% CI 0.99-1.63, p=0.06). Fourteen (5%) patients had died at last follow-up. <h3>Conclusion</h3> In a cohort of patients treated with modern radiotherapy techniques, rates of clinically apparent hypothyroidism after SCI were low, and most events occurred within the first two years. No thyroid dosimetric parameters were associated with the development of hypothyroidism, possibly due to a limited number of events.

Entire vs. Medial Supraclavicular Nodal Irradiation for Patients with High-Risk Node-Positive Breast Cancer

<h3>Purpose/Objective(s)</h3> We aimed to examine whether elective inclusion of the posterolateral supraclavicular node (SCL) region to the standard medial SCL target volume improves survival outcomes in patients with high-risk node-positive breast cancer undergoing regional nodal irradiation (RNI). <h3>Materials/Methods</h3> We retrospectively reviewed 544 consecutive women with high-risk breast cancer treated with postoperative chest wall/breast and RNI in our center from 1/2015-12/2016. High-risk features were defined as clinical or pathological stage N2-3b disease. Patients were classified into standard medial supraclavicular nodal irradiation (M-SCLI) group and the entire supraclavicular nodal irradiation (E-SCLI) group, which included both the medial and posterolateral SCL region. Disease-free survival (DFS) and overall survival (OS) curves were analyzed by the Kaplan-Meier method and compared using the log-rank test. Propensity-score matching (PSM) and multivariate cox regression analysis were used to evaluate the effect of SCL irradiation target volume on survival outcomes. <h3>Results</h3> The median follow-up time is 64.2 months (range, 6.2-82.6). In the entire cohort, the 5-year DFS rates were 78.5% in the M-SCLI group and 78.8% in the E-SCLI group(P=0.772), and the 5-year OS rates were 92.2% and 90.0% (P=0.210), respectively. Similarly, in the matched cohort, there was no significant difference between the M-SCLI and E-SCLI groups for 5-year DFS (78.2% vs. 77.7%, P=0.892) and OS (92.1% vs. 87.6%, P=0.071). Multivariate analysis demonstrated that E-SCLI was not independently prognostic for DFS (HR 0.80; 95%CI, 0.51 to 1.27; P=0.350) and OS (HR, 1.52; 95%CI, 0.79 to 2.94; P=0.212). The rate of SCL recurrence was low in both groups. <h3>Conclusion</h3> E-SCLI does not appear to be associated with improved DFS and OS in high-risk node-positive breast cancer. This study suggests that M-SCLI should remain standard for most node-positive breast cancer patients (≤N3b disease).

Effect and Toxicity of Bilateral Supraclavicular Lymph Node Irradiation on Stage III Lower Thoracic Esophageal Cancer After Radical Surgery

Surgery is the most important treatment for patients with lower thoracic esophageal squamous cell carcinoma (LTEC). Treatment failures, especially loco-regional recurrence involving mediastinal, abdominal, and supraclavicular lymph nodes area, are common after radical esophagectomy. Post-operative radiotherapy (PORT) has been demonstrated to benefit patients with stage III disease. However, whether bilateral supraclavicular lymph node radiotherapy should be included in the clinical target volume (CTV) remains unclear for those patients with lower thoracic esophageal cancer. So, we aim to explore whether PORT including the bilateral supraclavicular region can reduce the recurrence of supraclavicular lymph node, prolong overall survival and control distant metastasis in patients with stage III LTEC. We retrospectively analyzed 79 patients with stage III LTEC who had undergone radical surgery and PORT between 2010 and 2014. Among these patients, 51 patients received PORT which CTV excluding the bilateral supraclavicular lymph node region (Group A), and the remaining 28 patients received PORT which CTV including the supraclavicular region (Group B). Clinical outcomes (including local control, survival time, side-effects and prognostic factors) were analyzed with SPSS 25.0. Follow-up to August 2016, the 1-, 2-, and 3-year supraclavicular lymph nodes metastasis rates were 15.7%, 41.2%, 45.1% in Group A, 10.7%, 10.7%, 10.7% in Group B. The median overall survival (OS) of Group A and Group B were 25 and 24.5 months respectively. Univariate and multivariate analysis indicated that radiotherapy to the supraclavicular region decreased supraclavicular lymph node recurrence (p = 0.007/0.016, respectively) but did not prolong OS (p = 0.273/0.324) or control distant metastasis (p = 0.760/0.804). Our data also indicated that PORT including the supraclavicular region was not associated with the increase of radiotherapy-related complications (all p > 0.05). PORT including the bilateral supraclavicular region can reduce the recurrence of supraclavicular lymph node in patients with stage III LTEC without increase of treatment-related toxicities. However, PORT including bilateral supraclavicular region failed to prolong OS or control distant metastasis. Further prospective studies are warranted.

Supraclavicular Recurrence in Completely Resected (y)pN2 Non-Small Cell Lung Cancer: Implications for Postoperative Radiotherapy

Background: The clinical value and delineation of clinical target volume (CTV) of postoperative radiotherapy (PORT) in completely resected (y)pN2 non-small cell lung cancer (NSCLC) remain controversial. Investigations specifically focusing on the cumulative incidence and prognostic significance of initial disease recurrence at the supraclavicular region (SCR) in this disease population are seldom reported.Methods: Consecutive patients with curatively resected (y)pN2 NSCLC who received adjuvant chemotherapy from January 2013 to December 2018 at our cancer center were retrospectively examined. Disease recurrence at the surgical margin, ipsilateral hilum, and/or mediastinum was defined as loco-regional recurrence (LRR). Disease recurrence beyond LRR and SCR, was defined as distant metastasis (DM). Overall survival (OS1 and OS2) were calculated from surgery and disease recurrence to death of any cause, in the entire cohort and in patients with recurrent disease, respectively.Results: Among the 311 patients enrolled, PORT without elective supraclavicular nodal irradiation (ESRT) was performed in 94 patients and neoadjuvant chemotherapy was administered in 31 patients. With a median follow-up of 26 months, 203 patients developed recurrent disease, including 27 SCRs, among which 16 were without DM and 22 involved the ipsilateral supraclavicular region. The 1, 3, and 5-year cumulative incidence of SCR were 6.53, 13.0, and 24.7%, respectively. Chosen DM as a competing event, cN2, ypN2, not receiving lobectomy, and negative expression of CK7 were significantly associated with SCR using the univariate competing risk analysis, while ypN2 was identified as the only independent risk factor of SCR (p = 0.012). PORT significantly reduced LRR (p = 0.031) and prolonged OS1 (p = 0.018), but didn't impact SCR (p = 0.254). Pattern of failure analyses indicated that the majority of LRRs developed within the actuarial or virtual CTV of PORT, and 15 of the 22 ipsilateral SCRs could be covered by the virtual CTV of proposed ESRT. In terms of OS2, patients who developed SCR but without DM had intermediate prognosis, compared with those who had DM (p = 0.009) and those who had only LRR (p = 0.048).Conclusions: SCR is not uncommon and has important prognostic significance in completely resected (y)pN2 NSCLC. The clinical value of PORT and ESRT in such patients need to be further investigated.

Impact of Regional Nodal Irradiation and Hypofractionated Whole-Breast Radiation on Long-Term Breast Retraction and Poor Cosmetic Outcome in Breast Cancer Survivors

PurposeWe performed a prospective longitudinal study to determine predictors of long-term breast asymmetry in breast cancer patients treated with breast-conserving surgery and whole-breast external-beam radiotherapy (XRT). Patients and MethodsA total of 109 patients with stage 0 to III breast cancer treated with breast-conserving surgery followed by conventional (50 Gy plus boost) or hypofractionated (39.9 Gy with simultaneous integrated boost of 48 Gy) XRT were enrolled onto 2 studies of XRT-induced skin toxicity before (baseline), during, and 1 year after XRT. Using baseline and 1-year post-XRT photographs, breast asymmetry was objectively quantified by calculating the percentage breast retraction assessment (pBRA), with larger values indicating more asymmetry. Skin thickness ratio (STRA) values were calculated using ultrasound images. Univariate and multivariate analyses were conducted to determine the relationship among STRA-, patient-, tumor-, and treatment-related factors, and pBRA. ResultsSeventy-one patients (65%) had more breast asymmetry (positive change in pBRA) 1 year after XRT relative to baseline. Only pre-XRT STRA was associated with a higher pre-XRT baseline pBRA in multivariate analysis (P = .02). Larger breast volume, baseline pBRA, conventionally fractionated (vs. hypofractionated) XRT, supraclavicular nodal irradiation, and higher STRA at 1 year predicted for higher long-term pBRA in the multivariate model (all P < .05). Breast volume and supraclavicular nodal irradiation were associated with the largest changes in breast asymmetry (all P < .05). ConclusionThis prospective longitudinal study confirmed the known impact of breast volume, surgery, and XRT on breast asymmetry. We also found that supraclavicular nodal irradiation and conventionally fractionated XRT are associated with worse cosmetic outcome 1 year after XRT.

Radiation-induced oesophagitis in breast cancer: Factors influencing onset and severity for patients receiving supraclavicular nodal irradiation.

The aim of this study was to determine dosimetric factors, such as mean dose and oesophageal length, which may influence the incidence and severity of oesophagitis in breast cancer patients receiving radiotherapy to the supraclavicular nodes. This was a single-arm prospective observational study. Toxicity grading was undertaken twice weekly to determine the onset of grade 2 oesophagitis in consecutive patients prescribed IMRT to the breast or chest wall and supraclavicular fossa (SCF) nodes. Recorded variables included mean and maximum doses to the oesophagus, oesophageal length and pharynx length within the treatment area. Multivariate logistic regression and Fishers' exact test were used with a 0.05 significance level to compare the onset of grade 2 oesophagitis with these variables. A total of 77 patients were included in the study. Twenty-four (31%) patients reported grade 2 oesophagitis. There was a higher incidence of grade 2 oesophagitis in patients receiving a mean oesophageal dose of ≥31Gy compared to those receiving <31Gy (18/24 versus 6/24, respectively, P=0.025). There was a significant difference in the onset of grade 2 toxicity in patients who had ≥1cm of pharynx included in SCF fields compared with those with <1cm (15/24 versus 9/24, respectively, P=0.0116). The odds ratios for developing grade 2 oesophagitis were 3.2 (95% CI=1.05-9.62, P=0.04) for a mean dose of ≥31Gy and 3.4 (95% CI=1.19-9.5, P=0.022) for ≥1cm of pharynx in the SCF field. By limiting the mean dose to the irradiated oesophagus to <31Gy during the planning process and ensuring that <1cm of pharynx is included in the radiation field, oesophageal toxicity may be minimised.

The Effect of Regional Node Irradiation on the Thyroid Gland in the Breast Cancer Patients: The Clinical Significance of Optimization of Radiation Target Volume

Although current international consensus recommends considering regional node irradiation (RNI) even in high-risk early-stage breast cancer, the risk of radiotherapy (RT)-related late toxicities including radiation-induced-hypothyroidism (RIH) has been neglected so far. Here, we investigated the long-term contribution of RNI on the risk of RIH and whether optimizing RT target volumes for supraclavicular (SCV) lymph node could minimize its risk. We identified 4,073 patients who received adjuvant RT after surgery for breast cancer between 2007 and 2016 at a single institution. Patients were divided into three groups by the volume of regional RT field: no RNI (n=2,468), low SCV-RNI (cranial border at the subclavian artery according to ESTRO guideline, n=215), and standard-RNI (cranial border at the cricoid cartilage according to RTOG atlas, n=1,390). Development of subclinical or biochemical RIH was evaluated by medical chart review. The incidences of hypothyroidism were compared among three groups, and the dosimetric analysis was performed to estimate the Dmean to the thyroid in randomly-sampled matching patients (n = 200). At a median of 60 months (range, 5.2-140.2), 89 patients (2.2%) developed RIH (1.5% subclinical, 0.7% biochemical). The time interval from RT to detection of hypothyroidism was mean 30.2±24.0 months, and the 3- and 5-year rates were 1.3% and 2.2%. Patients with RNI had a significantly higher rate of hypothyroidism than patients without RNI (3.4% vs. 1.4%, P<.001). In RNI group (n = 1,605), low SCV-RNI was significantly associated with lowered risk of hypothyroidism than standard-RNI (0.5% vs. 3.8%, P<.001). After adjusting all confounders, standard-RNI was the only independent risk factor for development of RIH (vs. low SCV, HR 1.46, 95% CI, 1.05-2.03). In the dosimetric analysis, mean radiation dose to the thyroid was significantly lowered in low SCV-RNI group than standard-RNI group (2.9±1.9 Gy vs. 9.3±8.4 Gy P<.001). Standard supraclavicular lymph node irradiation increased the risk of newly developed hypothyroidism. However, optimization of RT target volume could reduce the lifelong RIH risk, which further supports adoption of smaller volume for supraclavicular lymph node in breast cancer with limited nodal tumor burden.

Breast board combined with a thermoplastic head mask immobilization can improve the reproducibility of the treatment setup for breast cancer patients receiving whole breast and supraclavicular nodal region irradiation

Objective To quantify the setup errors measured with kV cone-beam CT (CBCT) using breast board with or without a thermoplastic head mask in breast cancer patients who received whole breast and supraclavicular nodal region irradiation. Clinical target volume (CTV) to planning target volume (PTV) in 3 directions were also calculated. Methods The study included thirty patient receiving both whole breast and supraclavicular nodal region irradiation on Elekta Versa HD linear accelerators (Elekta Oncology Systems, Crawley, UK) between June 2016 and January 2018.The setup error data were retrospectively analyzed. All the patients were immobilized in the supine position on a breast board system (Carbon fibre breast board, Civco, Iowa, USA) with both arms raised. Twenty of the patients added an extra thermoplastic head mask to immobilize the neck. A CBCT scan was taken before treatment at the first 3 to 5 fractions and then once every week. Registration with the planning CT was performed and adjusted to match the target volume of the supraclavicular nodal region and the cervical vertebra by experienced medical staff, the position of the arms and the breast were also considered. For all patients the couch shifts in left-right (x), superior-inferior (y), anterior-posterior (z) were recorded. Statistical analysis included two-tails significance tests (t-Student and Manne-Whitney test for means, χ2 test for variances). Population of the two groups was compared in terms of distribution of the mean shift (systematic error) and their standard deviations (random error). Van Herk′s setup margin defined as MPTV=2.5Σ+ 0.7δ was calculated in patients with or without mask immobilization. Results Altogether, 56 images and 109 images were acquired in breast board only group and head mask group, respectively. Shifts of the breast board only group and the head mask group in x, y, z were 0.212±0.174 cm vs.0.272±0.242 cm (P=0.070); 0.364±0.246 cm vs.0.242±0.171 cm (P=0.001); 0.423±0.302 cm vs.0.364±0.269 cm (P=0.204). Proportion of the shift less than 5 mm in the breast board only group and the head mask group were 91.07% vs. 85.32%(P=0.294); 67.86% vs.89.91%(P=0.001); 67.86% vs.74.31%(P=0.381). The CTV to PTV margin in x, y, z were 0.645 cm, 0.981 cm, 1.317 cm in breast board only group and 0.873 cm, 0.709 cm, 0.961 cm in head mask group, respectively. Setup error in the x direction was significantly correlated with BMI (P=0.001). Conclusions For the alignment and immobilization of patients who received whole breast and supraclavicular nodal region irradiation, using a breast board in combination of a thermoplastic head mask may significantly help to reduce the shift variance in superior-inferior direction compared to using breast board only. The anterior-posterior error is relatively large, other immobilization device or patient alignment methods are needed to be further explored to improve the accuracy. Key words: Breast neoplasms/radiotherapy; Setup error; Cone-beam CT

P184 - Thyroid function post supraclavicular lymph node irradiation in patients with breast cancer

P184 - Thyroid function post supraclavicular lymph node irradiation in patients with breast cancer

28P - Breast board combined with a thermoplastic head mask immobilization can improve the reproducibility of the treatment setup for breast cancer patients who received whole breast and supraclavicular nodal region irradiation

28P - Breast board combined with a thermoplastic head mask immobilization can improve the reproducibility of the treatment setup for breast cancer patients who received whole breast and supraclavicular nodal region irradiation

Prognostic Impact of Elective Supraclavicular Nodal Irradiation for Patients with N1 Breast Cancer after Lumpectomy and Anthracycline Plus Taxane-Based Chemotherapy (KROG 1418): A Multicenter Case-Controlled Study.

PurposeThis study was conducted to evaluate the impact of supraclavicular lymph node radiotherapy (SCNRT) on N1 breast cancer patients receiving post-lumpectomy whole-breast irradiation (WBI) and anthracycline plus taxane-based (AT) chemotherapy.Materials and MethodsWe performed a case-control analysis to compare the outcomes of WBI and WBI plus SCNRT (WBI+SCNRT). Among 1,147 patients with N1 breast cancer who received post-lumpectomy radiotherapy and AT-based chemotherapy in 12 hospitals, 542 were selected after propensity score matching. Patterns of failure, disease-free survival (DFS), distant metastasis-free survival (DMFS), and treatment-related toxicity were compared between groups.ResultsA total of 41 patients (7.6%) were found to have recurrence. Supraclavicular lymph node (SCN) failure was detected in three patients, two in WBI and one in WBI+SCNRT. All SCN failures were found simultaneously with distant metastasis. There was no significant difference in patterns of failure or survival between groups. The 5-year DFS and DMFS for patients with WBI and WBI+SCNRT were 94.4% versus 92.6% (p=0.50) and 95.1% versus 94.5% (p=0.99), respectively. The rates of lymphedema and radiation pneumonitis were significantly higher in the WBI+SCNRT than in the WBI.ConclusionWe did not find a benefit of SCNRT for N1 breast cancer patients receiving AT-based chemotherapy.

Mapping patterns of nodal metastases in esophageal carcinoma: rethinking the clinical target volume for supraclavicular nodal irradiation.

To map detail distribution of metastatic supraclavicular (SCV) lymph nodes (LN) in esophageal cancer (EC) patients and determine the precise radiation therapy clinical target volume (CTV). A total of 101 thoracic esophageal carcinoma patients after surgery experienced SCV LN metastasis were retrospectively examined. The SCV region is further divided into four subgroups. Using hand drawings registration, nodes were mapped to a template computed tomogram to provide a visual impression of nodal frequencies and anatomic distribution. In all, 158 nodes were considered to be clinical metastatic in the SCV region in the 101 patients, 74 on the left and 84 on the right. Seven of 158 (4.4%) positive LN were located in group I, 78 of 158 (49.37%) were located in group II, 72 of 158 nodes (45.6%) were located in group III, 1 of 158 (0.63%) located in group IV. According to our results, the SCV group II and group III are considered to be the high risk regions of esophageal squamous cell carcinoma (ESCC) LN metastasis, which were defined as elective nodal irradiation (ENI) areas.

Mapping Patterns of Nodal Metastases in Esophageal Carcinoma: Rethinking the Clinical Target Volume for Supraclavicular Nodal Irradiation

Mapping Patterns of Nodal Metastases in Esophageal Carcinoma: Rethinking the Clinical Target Volume for Supraclavicular Nodal Irradiation

Combined photon-electron beams in the treatment of the supraclavicular lymph nodes in breast cancer: A novel technique that achieves adequate coverage while reducing lung dose

Radiation pneumonitis is a well-documented side effect of radiation therapy for breast cancer. The purpose of this study was to compare combined photon-electron, photon-only, and electron-only plans in the radiation treatment of the supraclavicular lymph nodes. In total, 13 patients requiring chest wall and supraclavicular nodal irradiation were planned retrospectively using combined photon-electron, photon-only, and electron-only supraclavicular beams. A dose of 50Gy over 25 fractions was prescribed. Chest wall irradiation parameters were fixed for all plans. The goal of this planning effort was to cover 95% of the supraclavicular clinical target volume (CTV) with 95% of the prescribed dose and to minimize the volume receiving ≥ 105% of the dose. Comparative end points were supraclavicular CTV coverage (volume covered by the 95% isodose line), hotspot volume, maximum radiation dose, contralateral breast dose, mean total lung dose, total lung volume percentage receiving at least 20Gy (V20Gy), heart volume percentage receiving at least 25Gy (V25Gy). Electron and photon energies ranged from 8 to 18MeV and 4 to 6MV, respectively. The ratio of photon-to-electron fractions in combined beams ranged from 5:20 to 15:10. Supraclavicular nodal coverage was highest in photon-only (mean = 96.2 ± 3.5%) followed closely by combined photon-electron (mean = 94.2 ± 2.5%) and lowest in electron-only plans (mean = 81.7 ± 14.8%, p < 0.001). The volume of tissue receiving ≥ 105% of the prescription dose was higher in the electron-only (mean = 69.7 ± 56.1cm3) as opposed to combined photon-electron (mean = 50.8 ± 40.9cm3) and photon-only beams (mean = 32.2 ± 28.1cm3, p = 0.114). Heart V25Gy was not statistically different among the plans (p = 0.999). Total lung V20Gy was lowest in electron-only (mean = 10.9 ± 2.3%) followed by combined photon-electron (mean = 13.8 ± 2.3%) and highest in photon-only plans (mean = 16.2 ± 3%, p < 0.001). As expected, photon-only plans demonstrated the highest target coverage and total lung V20Gy. The superiority of electron-only beams, in terms of decreasing lung dose, is set back by the dosimetric hotspots associated with such plans. Combined photon-electron treatment is a feasible technique for supraclavicular nodal irradiation and results in adequate target coverage, acceptable dosimetric hotspot volume, and slightly reduced lung dose.

Risk of Radiation Induced Carotid Artery Stenosis in Supraclavicular Lymph Node Irradiation in Breast Cancer Patients

Background: The risk of carotid vessel stenosis is high after radiotherapy (RT) to neck; however, carotid vessels are unavoidable during supraclavicular (SC-RT) in adjuvant treatment of breast cancer (BC). However, carotid vessels RT dose is less well-understood. We aimed to determine the carotid vessels doses received by different techniques for SC-RT. Materials and Methods: Thirty consecutive BC patients were planned to receive SC-RT and breast after breast conserving surgery (BCS) after taking 5 mm image slices on computed tomography (CT) simulation. Organs at risk (OAR) including carotid vessels, lungs, spinal cord alongwith clinical target volume (CTV) for primary tumor and lymph nodes were delineated. Comparative analysis was done between two treatment plans; three-field conformal radiation therapy (3F-CRT) and four field conformal RT (4F-CRT) for CTV and carotid vessels doses. Results: The 4F-CRT was found better than 3F-3DCRT regarding coverage and homogeneity of the CTV volume. The 98% of the CTV was covered by 84% dose in 3F-CRT and 95% in 4F-CRT (p 0.001). The carotid vessels maximum dose in the in 3F-CRT was 54.5 ± 1.3 Gy compared to 51.6 ± 1.3 Gy in 4F-CRT (p 0.014), however the mean dose did not differ significantly (p value 0.8). The ipsilateral lung dose did not differ between the two techniques (p Value 0.9). Conclusion: The 4F-CRT plan was found better than 3F-CRT in CTV coverage with minimal dose to the carotid vessel and without significant higher dose to the ipsilateral lung.