Nodal Irradiation Research Articles

PO-2355 Internal guidelines to reduce lymph-node contour variability for total marrow/lymph node irradiation

PO-2355 Internal guidelines to reduce lymph-node contour variability for total marrow/lymph node irradiation

OC-0260 Delayed tumor draining lymph node irradiation to maximize radioimmunotherapy combinations

OC-0260 Delayed tumor draining lymph node irradiation to maximize radioimmunotherapy combinations

PO-1264 Risk stratification for internal mammary lymph node irradiation based on dynamic MRI vessel imaging

PO-1264 Risk stratification for internal mammary lymph node irradiation based on dynamic MRI vessel imaging

SP-0195 Margins and elective nodal irradiation in PORT - How much do they matter?

SP-0195 Margins and elective nodal irradiation in PORT - How much do they matter?

PD-0230 One week hypofractionated breast radiotherapy acute toxicity with SIB and regional nodal irradiation

PD-0230 One week hypofractionated breast radiotherapy acute toxicity with SIB and regional nodal irradiation

PO-1513 The Roach formula and elective nodal irradiation for prostate cancer in the era of PSMA PET imaging

PO-1513 The Roach formula and elective nodal irradiation for prostate cancer in the era of PSMA PET imaging

PO-1296 Regional Nodal Irradiation in N+Breast cancer with complete pathologic response?- Clinical practice

PO-1296 Regional Nodal Irradiation in N+Breast cancer with complete pathologic response?- Clinical practice

PO-2257 An evaluation of IGRT strategies in N1 prostate cancer patients receiving nodal irradiation

PO-2257 An evaluation of IGRT strategies in N1 prostate cancer patients receiving nodal irradiation

PO-1454 SBRT for prostate cancer with or without Elective Nodal Irradiation

PO-1454 SBRT for prostate cancer with or without Elective Nodal Irradiation

SGRT-based DIBH radiotherapy practice for right-sided breast cancer combined with RNI: A retrospective study on dosimetry and setup accuracy.

We retrospectively studied the dosimetry and setup accuracy of deep inspiration breath-hold (DIBH) radiotherapy in right-sided breast cancer patients with regional nodal irradiation (RNI) who had completed treatment based on surface-guided radiotherapy (SGRT) technology by Sentinel/Catalyst system, aiming to clarify the clinical application value and related issues. Dosimetric indicators of four organs at risk (OARs), namely the heart, right coronary artery (RCA), right lung, and liver, were compared on the premise that the planning target volume met dose-volume prescription requirements. Meanwhile, the patients were divided into the edge of the xiphoid process (EXP), sternum middle (SM), and left breast wall (LBW) groups according to different positions of respiratory gating primary points. The CBCT setup error data of the three groups were contrasted for the treatment accuracy study, and the effects of different gating window heights on the right lung volume increases were compared among the three groups. Compared with free breath (FB), DIBH reduced the maximum dose of heart and RCA by 739.3±571.2 cGy and 509.8±403.8 cGy, respectively (p<0.05). The liver changed the most in terms of the mean dose (916.9±318.9 cGy to 281.2±150.3 cGy, p<0.05). The setup error of the EXP group in the anterior-posterior (AP) direction was 3.6±4.5mm, which is the highest among the three groups. The right lung volume increases in the EXP, SM, and LBW groups were 72.3%, 69.9%, and 67.2%, respectively (p=0.08), and the corresponding breath-holding heights were 13.5±3.7mm, 10.3±2.4mm, and 9.6±2.8mm, respectively (p<0.05). SGRT-based DIBH radiotherapy can better protect the four OARs of right-sided breast cancer patients with RNI. Different respiratory gating primary points have different setup accuracy and breath-hold height.

A comparison of acute patient-reported outcomes in breast cancer patients with and without regional nodal irradiation using the ESAS and PRFS tool

Regional nodal irradiation (RNI) is commonly administered in patients with breast cancer with node-positive disease to prevent cancer recurrence. The purpose of this study is to identify whether RNI is associated with greater acute symptom burden from baseline to 1 to 3months post completion of radiotherapy (RT) when compared to localized RT. Patient and treatment characteristics were collected prospectively for breast cancer patients with and without RNI from February 2018 to September 2020. The Edmonton Symptom Assessment System (ESAS) and Patient-Reported Functional Status (PRFS) tool were completed by patients at baseline, weekly during RT, and at a 1- to 3-month follow-up visit. The Wilcoxon rank-sum or Fisher exact tests were used to compare variables between patients with or without RNI. A total of 781 patients were included in the analysis. Baseline symptom reporting was similar between cohorts, with the exception of PRFS scores (p = 0.0023), which were worse in patients receiving RNI. Across all time points, differences in outcomes between cohorts were minimal, except for lack of appetite (p = 0.03) and PRFS scores (p = 0.049), which were significantly aggravated in patients treated with RNI. There is insufficient evidence to suggest that RNI is associated with greater symptom burden as assessed with the ESAS. Further research should be conducted over a longer time period to determine the impact of late effects of RNI on patient-reported symptoms.

Risk of Radiation Dermatitis in Patients With Skin of Color Who Undergo Radiation to the Breast or Chest Wall With and Without Regional Nodal Irradiation

Acute radiation dermatitis (ARD) is common after radiation therapy for breast cancer, with data indicating that ARD may disproportionately affect Black or African American (AA) patients. We evaluated the effect of skin of color (SOC) on physician-reported ARD in patients treated with radiation therapy. We identified patients treated with whole breast or chest wall ± regional nodal irradiation or high tangents using 50 Gy in 25 fractions from 2015 to 2018. Baseline skin pigmentation was assessed using the Fitzpatrick scale (I=light/pale white to VI=black/very dark brown) with SOC defined as Fitzpatrick scale IV to VI. We evaluated associations among SOC, physician-reported ARD, late hyperpigmentation, and use of oral and topical treatments for RD using multivariable models. A total of 325 patients met eligibility, of which 40% had SOC (n=129). On multivariable analysis, Black/AA race and chest wall irradiation had a lower odds of physician-reported grade 2 or 3 ARD (odds ratio [OR], 0.110; 95% confidence interval [CI], 0.030-0.397; P=.001; OR, 0.377; 95% CI, 0.161-0.883; P=.025), whereas skin bolus (OR, 8.029; 95% CI, 3.655-17.635; P=0) and planning target volume D0.03cc (OR, 1.001; 95% CI, 1.000-1.001; P=.028) were associated with increased odds. On multivariable analysis, SOC (OR, 3.658; 95% CI, 1.236-10.830; P=.019) and skin bolus (OR, 26.786; 95% CI, 4.235-169.432; P=0) were associated with increased odds of physician-reported late grade 2 or 3 hyperpigmentation. There was less frequent use of topical steroids to treat ARD and more frequent use of oral analgesics in SOC versus non-SOC patients (43% vs 63%, P < .001; 50% vs 38%, P=.05, respectively). Black/AA patients exhibited lower odds of physician-reported ARD. However, we found higher odds of late hyperpigmentation in SOC patients, independent of self-reported race. These findings suggest that ARD may be underdiagnosed in SOC when using the physician-rated scale despite this late evidence of radiation-induced skin toxicity.

Abstract CT157: Combination of nivolumab with standard of care in the management of grade group 5 prostate cancer: Interim analysis of a phase II trial

Abstract Survival outcomes of grade group 5 (GG5) prostate cancer (PCa) after standard of care therapy (SOC) remain poor. Evidence suggest that high dose rate brachytherapy (HDR) and androgen depravation therapy (ADT) can serve as immune modulators. We hypothesize that the combination of HDR, ADT, and immune checkpoint inhibitors (ICI) may synergize to improve immune response and disease control. Here we report an interim analysis of a single-center single-arm phase II trial exploring this novel combination therapy with nivolumab for GG5 PCa. Patients were enrolled from 9/2018 to 4/2021 and required to have GG5 PCa with &amp;gt; 30% positive cores and receive ICI plus SOC regimen, comprising ADT, external beam RT (EBRT), and HDR. ICI (240 mg) was administered every 2 weeks for 4 doses beginning 4 weeks prior to HDR. HDR consisted of two 1150 cGy implants. EBRT followed HDR and consisted of 4500 cGy in 25 fractions. Total ADT length and elective nodal radiotherapy were per physician discretion. Biopsies were taken at time of diagnosis, HDR, and 1-month post HDR. Biopsy tumor samples underwent genomic profiling. Major pathologic response (MPR) was defined as &amp;lt; 17% positive cores. Wilcoxon test and Area Under the Curve (AUC) Receiver Operating Characteristics (ROC) curves were used for statistical analyses. Toxicity was evaluated according to CTCAE v5.0. The historic control cohort consisted of all patients treated with SOC between 1/2013 to 11/2021 and met all study inclusion/exclusion criteria. Cox regression was used to calculate 2-year (2Y) risk of metastasis with censorship at 24 months (m). Median follow up (mFUP) defined from diagnostic biopsy. Of 34 patients who received 2 or more doses of ICI, 1 patient (3%) experienced a dose limiting toxicity of autoimmune hepatitis (AH). The incidence of all grade 3 toxicity related to ICI at 3 and 6 months were both 3% (n=1; AH and QT prolongation, respectively). There was no grade 4+ toxicity at 3 m, nor any grade 3+ toxicity at 6 m. Two subjects were withdrawn from study, leaving 32 evaluable for clinical outcomes. mFUP of ICI cohort was 32 m with a 2Y PSA failure rate of 6%. CD8A, STING, ANPEP, and multiple immune signatures were associated with an early MPR (p &amp;lt; 0.05) with ICI. The Ricketts_Immunosuppression genomic signature strongly correlated with MPR to ICI (AUC = 0.7, p = 0.01). The control cohort consisted of 59 patients with a mFUP of 35 m and a 2Y PSA failure rate of 19%. ICI demonstrated an 88% reduction in 2Y risk of metastasis compared to controls (HR = 0.12, 95% CI, 0.02 - 1.0, p = 0.05). Combination of ICI with SOC for GG5 PCa is safe and associated with a clinically significant improvement in disease control. Key genomic features were identified to predict for early MPR to ICI. Ricketts_Immunosuppression was identified as a potential biomarker for ICI-sensitive tumor subtypes. Final analyses are anticipated in late 2023. Clinical trial information: NCT03543189. Citation Format: John Michael Bryant, Maria Sandoval, Ryan Putney, Corrado Caslini, Shivanshu Awasthi, Esther Katende, Angelina Fink, Syeda Mahrukh H Naqvi, Youngchul Kim, Jingsong Zhang, Jong Park, Amparo Serna, Julio Pow-Sang, Michael Poch, Roger Li, Brandon Manley, Arash Naghavi, Javier Torres-Roca, G. Daniel Grass, Sungjune Kim, Kujtim Latifi, Dylan Hunt, Peter A. Johnstone, Jasreman Dhillon, Rohit Jain, Daniel Fernandez, Kosj Yamoah. Combination of nivolumab with standard of care in the management of grade group 5 prostate cancer: Interim analysis of a phase II trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT157.

The Axillary Lateral Vessel Thoracic Junction Is Not an Organ at Risk for Breast Cancer–Related Lymphedema

Breast-cancer related lymphedema (BCRL) is a treatment complication that significantly reduces patient quality of life. Regional nodal irradiation (RNI) may increase the risk of BCRL. Recently, a region of the axilla known as the axillary-lateral thoracic vessel juncture (ALTJ) was identified as a potential organ-at-risk (OAR). Here, we set to validate whether radiation dose to the ALTJ is associated with BCRL. We identified patients with stage II-III breast cancer treated with adjuvant RNI from 2013-2018, excluding those with BCRL pre-radiation. We defined BCRL as difference in arm circumference between the ipsilateral and contralateral limb >2.5 cm at any 1 encounter or ≥2 cm on ≥2 visits. All patients suspected of having BCRL at routine follow-up visits were referred to physical therapy for confirmation. The ALTJ was retrospectively contoured, and dose metrics were collected. Cox proportional hazards regression models were used to test the association between clinical and dosimetric parameters with the development of BCRL. Population includes 378 patients with median age 53 years, median body mass index (BMI) 28.4 kg/m2, 71% underwent mastectomy, and median 18 axillary nodes removed. Median follow-up was 70 months (IQR, 55-89.7 months). BCRL developed in 101 patients at a median of 18.9 months (IQR, 9.9-32.4 months) with a corresponding 5-year cumulative incidence BCRL of 25.8%. On multivariate analysis, none of the ALTJ metrics were associated with BCRL risk. Only increasing age, increasing BMI, and increasing number of nodes, were associated with a higher risk of developing BCRL The 6-year LRR rate is 3.2%, axillary recurrence rate is 1.7%, and isolated axillary recurrence rate is 0%. The ALTJ is not validated as a critical OAR for reducing BCRL risk. Until such an OAR is discovered, the axillary PTV should not be modified or dose reduced in efforts to reduce BCRL.

Treatment-related toxicity using prostate bed versus prostate bed and pelvic lymph node radiation therapy following radical prostatectomy: A national population-based study

Purpose There is debate about the effectiveness and toxicity of pelvic lymph node (PLN) irradiation in addition to prostate bed radiotherapy when used to treat disease recurrence following radical prostatectomy. We compared toxicity from radiation therapy (RT) to the prostate bed and pelvic lymph nodes (PBPLN-RT) with prostatebed only radiation therapy (PBO-RT) following radical prostatectomy. Methods and Materials Patients with prostate cancer who underwent post-prostatectomy RT between 2010 and 2016 were identified by using the National Prostate Cancer Audit (NPCA) database. Follow-up data was available up to December 31, 2018. Validated outcome measures, based on a framework of procedural and diagnostic codes, were used to capture ≥Grade 2 gastrointestinal (GI) and genitourinary (GU) toxicity. An adjusted competing-risks regression analysis estimated subdistribution hazard ratios (sHR). A sHR > 1 indicated a higher incidence of toxicity with PBPLN-RT than with PBO-RT. Results 5-year cumulative incidences in the PBO-RT (n = 5,087) and PBPLNRT (n = 593) groups was 18.2% and 15.9% for GI toxicity, respectively. For GU toxicity it was 19.1% and 20.7%, respectively. There was no evidence of difference in GI or GU toxicity after adjustment between PBO-RT and PBPLN-RT (GI: adjusted sHR, 0.90, 95% CI, 0.67–1.19; P = 0.45); (GU: adjusted sHR, 1.19, 95% CI, 0.99–1.44; P = 0.09). Conclusions This national population-based study found that including PLNs in the radiation field following radical prostatectomy is not associated with a significant increase in rates of ≥Grade 2 GI or GU toxicity at 5 years.

Impact of the Extremities Positioning on the Set-Up Reproducibility for the Total Marrow Irradiation Treatment

Total marrow (lymph node) irradiation (TMI/TMLI) delivery requires more time than standard radiotherapy treatments. The patient's extremities, through the joints, can experience large movements. The reproducibility of TMI/TMLI patients' extremities was evaluated to find the best positioning and reduce unwanted movements. Eighty TMI/TMLI patients were selected (2013-2022). During treatment, a cone-beam computed tomography (CBCT) was performed for each isocenter to reposition the patient. CBCT-CT pairs were evaluated considering: (i) online vector shift (OVS) that matched the two series; (ii) residual vector shift (RVS) to reposition the patient's extremities; (iii) qualitative agreement (range 1-5). Patients were subdivided into (i) arms either leaning on the frame or above the body; (ii) with or without a personal cushion for foot positioning. The Mann-Whitney test was considered (p < 0.05 significant). Six-hundred-twenty-nine CBCTs were analyzed. The median OVS was 4.0 mm, with only 1.6% of cases ranked < 3, and 24% of RVS > 10 mm. Arms leaning on the frame had significantly smaller RVS than above the body (median: 8.0 mm/6.0 mm, p < 0.05). Using a personal cushion for the feet significantly improved the RVS than without cushions (median: 8.5 mm/1.8 mm, p < 0.01). The role and experience of the radiotherapy team are fundamental to optimizing the TMI/TMLI patient setup.

Multi-Institutional Clinical Outcomes of Biopsy Gleason Grade Group 5 Prostate Cancers Treated With Contemporary High-Dose Radiation and Long-Term Androgen Deprivation Therapy

AimsThis multicentric retrospective study reports long-term clinical outcomes of non-metastatic grade group 5 prostate cancers treated with external beam radiotherapy (EBRT) alone with long-term androgen deprivation therapy (ADT). Materials and methodsPatients treated across 19 institutions were studied. The key endpoints that were evaluated were 5-year biochemical recurrence-free survival (bRFS), metastases-free survival (MFS), overall survival, together with EBRT-related acute and late toxicities. The impact of various prognostic factors on the studied endpoints was analysed using univariate and multivariate analyses. ResultsAmong the 462 patients, 88% (405) had Gleason 9 disease and 31% (142) had primary Gleason pattern 5. A prostate-specific membrane antigen positron emission tomography-computed tomography scan was used for staging in 33% (153), 80% (371) were staged as T3/T4 and 30% (142) with pelvic nodal disease. The median ADT duration was 24 months; 66% received hypofractionated EBRT and 71.4% (330) received pelvic nodal irradiation. With a median follow-up of 56 months, the 5-year bRFS, MFS and overall survival were 73.1%, 77.4% and 90.5%, respectively. Primary Gleason pattern 5 was associated with worse bRFS, MFS and overall survival with hazard ratios of 0.51 (95% confidence interval 0.35 to 0.73, P < 0.001), 0.64 (95% confidence interval 0.43 to 0.96, P = 0.031) and 0.52 (95% confidence interval 0.28 to 0.97, P = 0.040), respectively, whereas pelvic nodal disease was associated with worse bRFS (hazard ratio 0.67, 95% confidence interval 0.46 to 0.98, P = 0.039) and MFS (hazard ratio 0.56, 95% confidence interval 0.37 to 0.85, P = 0.006). The acute and late radiation-related toxicities were low overall and pelvic nodal irradiation was associated with higher toxicities. ConclusionContemporary EBRT and long-term ADT led to excellent 5-year clinical outcomes and low rates of toxicity in this cohort of non-metastatic grade group 5 prostate cancers. Primary Gleason pattern 5 and pelvic node disease portends inferior clinical outcomes.

MP32-11 FACTORS THAT PREDICT EARLY SALVAGE CYSTECTOMY POST-TRIMODAL THERAPY: RESULTS OF A MULTI-INSTITUTIONAL CANADIAN COHORT

You have accessJournal of UrologyCME1 Apr 2023MP32-11 FACTORS THAT PREDICT EARLY SALVAGE CYSTECTOMY POST-TRIMODAL THERAPY: RESULTS OF A MULTI-INSTITUTIONAL CANADIAN COHORT Landan Macdonald, Ronald Kool, Gautier Marcq, Girish Kulkarni, Rodney Breau, Bobby Shayegan, Michael Kim, Ionut Busca, Hamidreza Abdi, Michael Uy, Mark Dawidek, Gagan Fervaha, Fabio Cury, Nimira Alimohamed, Jonathan Izawa, Claudio Jeldres, Robert Siemens, Peter Black, Wassim Kassouf, and Ricardo Rendon Landan MacdonaldLandan Macdonald More articles by this author , Ronald KoolRonald Kool More articles by this author , Gautier MarcqGautier Marcq More articles by this author , Girish KulkarniGirish Kulkarni More articles by this author , Rodney BreauRodney Breau More articles by this author , Bobby ShayeganBobby Shayegan More articles by this author , Michael KimMichael Kim More articles by this author , Ionut BuscaIonut Busca More articles by this author , Hamidreza AbdiHamidreza Abdi More articles by this author , Michael UyMichael Uy More articles by this author , Mark DawidekMark Dawidek More articles by this author , Gagan FervahaGagan Fervaha More articles by this author , Fabio CuryFabio Cury More articles by this author , Nimira AlimohamedNimira Alimohamed More articles by this author , Jonathan IzawaJonathan Izawa More articles by this author , Claudio JeldresClaudio Jeldres More articles by this author , Robert SiemensRobert Siemens More articles by this author , Peter BlackPeter Black More articles by this author , Wassim KassoufWassim Kassouf More articles by this author , and Ricardo RendonRicardo Rendon More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003265.11AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Trimodal therapy (TMT) is an alternative to radical cystectomy for the treatment of muscle-invasive bladder cancer (MIBC) in well selected patients. Rates of recurrence and non-response to TMT have been reported to be up to 30%. Salvage radical cystectomy (sRC) is an option for patients with persistent or recurrent disease. Patient characteristics that predict success with sRC are not well defined. We report the outcomes of patients undergoing sRC from a multi-institutional Canadian cohort. METHODS: Patients who underwent sRC post-TMT were identified retrospectively from the TMT Canadian Collaboration. This collaboration includes patients treated at 14 Canadian Institutions. Patient characteristics, histopathology findings, and survival outcomes were evaluated. Patients undergoing sRC were grouped into immediate (within 6 months post-TMT) and delayed sRC (more than 6 months post-TMT). RESULTS: There were 864 patients included in this series, of which 64 underwent sRC. Of those, 17 underwent immediate sRC, and 47 delayed sRC. Patients who had an immediate salvage were more likely to be younger, male, have a higher tumor and nodal stage, variant histology, hydronephrosis and radiation to bladder only compared to those who underwent a delayed sRC (Table 1). Most patients underwent PLND (86%) with a median nodal count of 9 (4-16). Most patients underwent an ileal conduit (96.9%), and most had a negative margin (81.2%). The median overall survival (OS) for the entire cohort was 89 months. The OS between immediate and delayed sRC was 20 months and 129 months respectively. CONCLUSIONS: sRC is feasible and has acceptable oncological outcomes. Patients who undergo delayed sRC have a much better prognosis compared to those who underwent immediate sRC. This highlights the importance of patient selection when deciding between treatment options. Patients with higher T and N stage, variant histology, hydronephrosis and treated with radiation only are at an increased risk for early salvage. Source of Funding: This project has been supported by the Canadian Bladder Cancer Information System Collaborative (CBCIS) and Bladder Cancer Canada. CBCIS has received unrestricted grants or in-kind support from Bladder Cancer Canada, Merck, Roche, Astra Zeneca, Pfizer/EMD Serono, Seagen, and Bristol-Myers Squibb. There is no direct role or influence from this funding on this work. © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e444 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Landan Macdonald More articles by this author Ronald Kool More articles by this author Gautier Marcq More articles by this author Girish Kulkarni More articles by this author Rodney Breau More articles by this author Bobby Shayegan More articles by this author Michael Kim More articles by this author Ionut Busca More articles by this author Hamidreza Abdi More articles by this author Michael Uy More articles by this author Mark Dawidek More articles by this author Gagan Fervaha More articles by this author Fabio Cury More articles by this author Nimira Alimohamed More articles by this author Jonathan Izawa More articles by this author Claudio Jeldres More articles by this author Robert Siemens More articles by this author Peter Black More articles by this author Wassim Kassouf More articles by this author Ricardo Rendon More articles by this author Expand All Advertisement PDF downloadLoading ...

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 &lt;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.

Dose-Volume Predictors for Radiation Esophagitis in Patients With Breast Cancer Undergoing Hypofractionated Regional Nodal Radiation Therapy

Our objective was to assess the incidence and dose-volume predictors of radiation esophagitis (RE) in patients with breast cancer undergoing hypofractionated regional nodal irradiation. Eligible patients who received intensity modulated radiation therapy (RT) at the chest wall, the supraclavicular/infraclavicular fossa, level II axilla, and/or the internal mammary chain after mastectomy were included. The prescribed dose was 43.5 Gy in 15 fractions. RE was evaluated weekly during RT and at 1 and 2 weeks, followed by 3 and 6 months after RT, and was graded according to National Cancer Institute Common Toxicity Criteria for Adverse Events, version 3.0. The esophagus was contoured from the lower border level of the cricoid cartilage to the lower margin of the aortic arch. Esophageal total volume, mean dose, maximum dose, and the relative volumes (RV) and absolute volumes (AV) receiving at least 5 to 45 Gy by 5-Gy increments (RV5-RV45 and AV5-AV45) were evaluated. Univariable and multivariable logistic regression analyses were performed to determine risk factors for RE, and receiver operating characteristic curves were obtained to identify the thresholds of esophageal dosimetric parameters. In total, 298 patients were included between May 8, 2020, and January5,2022 (minimum post-RT follow-up: 6 months). Grade 2 and 3 RE incidence was 40.9% (122/298) and 0.3% (1/298), respectively. No grade 4 or 5 RE was observed. Esophageal RV20-RV40 and AV35-AV40 were significantly associated with the risk of grade ≥2 RE after adjusting for tumor laterality and internal mammary nodal irradiation. RV25 and AV35 were optimum dose-volume predictors for grade ≥2 RE at thresholds 20% for RV25 (35.9% vs 60.9%; P=.04) and 0.27 mL for AV35 (31.0% vs 54.6%; P=.04). RE is common in patients with breast cancer undergoing hypofractionated regional nodal irradiation. Maintaining the upper esophageal V25 at <20% and V35 at <0.27 mL may decrease the risk of RE.