End Of Radiotherapy Research Articles

Abstract PO-091: Does volumetric-modulated arc therapy improve anal cancer treatment outcome and reduce toxicity: A single institution experience

Abstract Introduction: Anal cancer (AC) is a relatively rare malignancy that can have poor prognosis if not treated at an early stage. It is difficult to conduct phase 3 clinical trials due to the low incidence rate. Standard treatment of locally advanced AC has been almost always concurrent chemotherapy and radiation therapy for several decades. In recent years, volumetric-modulated arc therapy (VMAT) has emerged as a new technology designed to reduce toxicities. The purpose of this retrospective study is to share our experience in eighteen years to see if this innovative treatment has translated into a better outcome for AC patients. Methods: This study was approved by our institution’s Research Ethics Board (REB). All electronic medical records (EMR) of patients with anal canal, anal or peri-anal malignancies who were seen between January 2002 and December 2019 were reviewed. We were using conventional radiation therapy (CRT) until 2012 when we adopted VMAT as standard radiation modality for definitive treatment of patients with locally advanced AC. We excluded melanoma, lymphoma, and adenocarcinoma of the rectum involving anal canal. Squamous cell carcinoma of the anal canal involving rectum or colon was included in the study. A total of 182 consecutive patients meet the selection criteria for analysis. Patient demographics, treatment modalities, survival and toxicity data were recorded. Kaplan-Meier survival curves and life tables using SPSS software were generated to compare outcome of patients that received VMAT versus CRT starting from the end of radiation therapy, i.e. not from date of diagnosis as some other studies in the literature. Results: Median age of our cohort was 61 years (33-98), 116 (64%) were female, majority (72%) were locally advanced stage 2 or 3 (AJCC-7), 4% were HIV positive, 62% were squamous cell carcinoma, 86% received radiotherapy, including 45% VMAT and 40% CRT, 74% received 45 Gy or higher dose, 49% had surgery, and 72% had chemotherapy. Median follow up was 29 months. The 3/5 year overall survival (OS) are 60%/47%, and the 3/5 year local control (LC) are 73%/67%, respectively. Within the sub-groups that received radiation treatment, VMAT had a higher 3/5 year OS of 68%/49%, versus CRT at 54%/45%, p<0.05 and p=0.34, respectively. The 3/5 year LC was not significantly different, 69%/60% versus 74%/71% (p=0.28 and p=0.15, respectively). There was no treatment related death and 20% had Grade 3-4 acute toxicity. Late toxicity analysis was not reliable because of the nature of this retrospective study with no consistent long-term follow up toxicity data available in EMR. The rate of diverting colostomy is high (29.7%), but mostly done prior to treatment due to obstruction. Conclusions: AC treatment outcome in our institution is comparable to published historical data. Our findings support the use of VMAT for localized AC with better OS and similar LC. Large prospective randomized controlled trials are needed to evaluate the benefit of reducing late toxicities from VMAT comparing to CRT. Citation Format: Ming Pan, Nitin Rai. Does volumetric-modulated arc therapy improve anal cancer treatment outcome and reduce toxicity: A single institution experience [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-091.

Hematological toxicity in patients with solid malignant tumors treated with radiation – Temporal analysis, dose response and impact on survival

PurposeTo describe the kinetics of the peripheral blood components after radiotherapy, to examine radiation exposure vs. End-of-Radiation-Therapy (EoRT) counts and to associate the EoRT lymphocyte count with death and cancer treatment failure. Materials and methodsCohort study of patients who received curative intent radiotherapy for solid tumor diagnoses from 2009-2016 at Rigshospitalet, Copenhagen and had available 3D radiation exposure data. We illustrated peripheral blood count kinetics within 12 months before and after radiotherapy start and analyzed the impact of the irradiated body volume. We investigated overall survival and cancer treatment failure according to EoRT lymphopenia using Cox regression analyses. ResultsWe analyzed 4055 patients with both pre-treatment and EoRT platelet counts and 2318 patients who also had neutrophil and lymphocyte counts. Only the lymphocyte decline after radiotherapy start was clinically relevant and remained low one year after radiotherapy. The higher the volume of the body exposed to radiation, the lower the EoRT blood counts. Female gender (p < 0.001), number of fractions (p = 0.010), dose-volume (p < 0.001) and concomitant use of chemotherapy, particularly the platinum compounds (p < 0.001) were independently associated with a lower EoRT lymphocyte count. Patients with head and neck cancer had the lowest EoRT lymphocyte count. Patients with lymphopenia had a higher risk of death in the year after radiotherapy, compared with patients with no lymphopenia. ConclusionRadiation schemes with fewer fractions and radiation techniques allowing reduction of the volume of the body exposed to radiation could be expected to better preserve patients’ immune function.

A Risk Prediction Model by LASSO for Radiation-Induced Xerostomia in Patients With Nasopharyngeal Carcinoma Treated With Comprehensive Salivary Gland-Sparing Helical Tomotherapy Technique.

ObjectiveThis study aimed to develop a least absolute shrinkage and selection operator (LASSO)-based multivariable normal tissue complication probability (NTCP) model to predict radiation-induced xerostomia in patients with nasopharyngeal carcinoma (NPC) treated with comprehensive salivary gland–sparing helical tomotherapy technique.Methods and MaterialsLASSO with the extended bootstrapping technique was used to build multivariable NTCP models to predict factors of patient-reported xerostomia relieved by 50% and 80% compared with the level at the end of radiation therapy within 1 year and 2 years, R50-1year and R80-2years, in 203 patients with NPC. The model assessment was based on 10-fold cross-validation and the area under the receiver operating characteristic curve (AUC).ResultsThe prediction model by LASSO with 10-fold cross-validation showed that radiation-induced xerostomia recovery could be predicted by prognostic factors of R50-1year (age, gender, T stage, UICC/AJCC stage, parotid Dmean, oral cavity Dmean, and treatment options) and R80-2years (age, gender, T stage, UICC/AJCC stage, oral cavity Dmean, N stage, and treatment options). These prediction models also demonstrated a good performance by the AUC.ConclusionThe prediction models of R50-1year and R80-2years by LASSO with 10-fold cross-validation were recommended to validate the NTCP model before comprehensive salivary gland–sparing radiation therapy in patients with NPC.

Impact of radiotherapy in head and neck regions on periodontal and oral hygiene conditions

Objective: Evaluate the influence of head and neck radiotherapy dose on periodontal tissue for to understanding of its adverse effects, and consequently to propose strategies to reduce its severity. Methodology: An observational, longitudinal and prospective study with intraoral clinical examinations performed before radiotherapy (T0) and immediately after the end of radiation therapy. The clinical data collected regarding oral and periodontal hygiene conditions were visible plaque index (VPI), gingival bleeding index (GBI), probing depth (PD), gingival recession area, clinical attachment level (CAL), degree of mobility and presence or absence of suppuration. In addition, data such as radiation dose, fractionation and duration of radiotherapy were reported. Results: Fourteen patients were evaluated, of which 11 had periodontitis after the radiotherapy, and 9 had poor oral hygiene conditions after the radiotherapy. Seven of the 11 subjects with periodontitis presented tumors in the oral cavity. There was a decrease in visible plaque index (VPI) and gingival bleeding index (GBI). The research was unable to establish a significant association between radiation therapy and oral hygiene condition and periodontitis. Conclusion: Poor oral hygiene conditions predominated in the sample, which can be associated with the presence of debilitating conditions. Direct radiation on the oral cavity may have an influence on the development of periodontitis. The development of gingivitis only and periodontitis was not influenced by dose, fraction or duration of radiotherapy in the study period.

Evaluation of an interocclusal acrylic block for prevention of post radiation trismus

Aim: The aim of this study is to evaluate the efficacy of an interocclusal acrylic bite block as a preventative and conservative tool to prevent or minimize post radiation trismus in an effort to improve the quality of life of irradiated patients. Patients and Methods: Twenty patients with confirmed newly diagnosed head and neck cancer planned for radiation therapy, were selected. A custom-made inter occlusal acrylic splint was fabricated for each patient before radiation therapy started. Physiotherapy - using the acrylic block and assisted range of motion exercises - were instructed for the patients during the first 12 months following end of radiation therapy. Maximum interincisal openings were recorded prior to initiation of radiation therapy and then readings were taken monthly after completion of radiation therapy for 12 months. Results: All patients except one have shown decrease in inter incisal openings. The decrease was statistically insignificant and non-of the patients included in this study exhibited trismus. Conclusion: In this observational study the use of the inter occlusal acrylic block has shown promise in preventing post radiation trismus in addition to being cost effective. Further studies with more standardization and randomization are required to further prove the efficacy of this method.

C-Reactive Protein is a Poor Marker of Baseline Inflammation in Prostate Cancer and Response to Radiotherapy or Androgen Ablation

C-Reactive Protein (CRP) is an acute phase reactant used as a general marker for inflammation. There is some evidence that elevated levels are associated with increased risk of prostate cancer development, PSA, Gleason score, and decreased response to chemotherapy and radiotherapy (RT). Available literature largely focuses on pre-therapeutic levels as a prognostic marker. We seek to establish whether CRP levels reflect inflammation caused by prostate cancer before and in response to RT with or without prior androgen ablation (AA). This study included 209 patients who had a CBC, PSA, and CRP taken at up to four different time points. Labs were performed prior to AA via leuprolide injection (pre-AA), up to one week prior to RT (pre-RT), during the final week of RT (post-RT), and 3 months following RT completion (FU). Prior to RT, 33% of patients had received prior prostatectomy and 50.7% had received AA. Radiation fields included pelvic lymph nodes in 82% of patients. For comparisons at each time point, CRP had a significant relationship with WBCs pre-AA (p-value = 0.0050), pre-RT (p-value = 0.0170), and post-RT (p-value = 0.0113), but not at FU (p = .096). CRP had no significant relationship with PSA at any time points. For those who did or did not receive AA, pre-RT mean PSA was significantly lower (2.3 vs 5.4, p-value = 0.0072) while CRP was not. Pre-AA, pre-RT, and post-RT CRP levels were not significantly related to FU-PSA. No CRP levels were associated with risk groups. Only PSA significantly changed from pre-AA to pre-RT (p-value<0.0001). PSA, WBCs, and lymphocytes significantly decreased from pre-RT to post-RT, with significant recovery from post-RT to FU (p-value<0.0001 for all six comparisons), though still with overall significant change from pre-RT to FU (p-value = 0.0054, p-value<0.0001, p-value<0.0001, respectively). CRP did not significantly change during any period, nor significantly relate to changes in WBCs or PSA. There was a significant difference between the treated vs. untreated lymph node groups in post-RT lymphocytes (p-value<0.0001), FU-lymphocytes (p-value<0.0001), post-RT-WBCs (p-value = 0.0004), and FU-WBCs (p-value = 0.0141). CRP was not significantly different between these groups. Our results demonstrate a lack of clinical utility for CRP as a marker of the inflammatory effects of prostate cancer. It has no correlation with PSA levels or trends, before or after radiation therapy, with or without androgen ablation. It does not change with significant PSA decrease after androgen ablation and corresponding decrease in cancer activity. It does not change at the end of radiation therapy despite significant changes in lymphocytes and WBCs. It does not change with 3-month follow-up to correspond with either significant recovery of lymphocytes and WBCs or a decrease of radiation-induced inflammation.

Diagnosis and treatment of radiation intestinal injury: current status and perspectives

Radiation intestinal injury (RII) refers to the intestinal complication resulting from radiation therapy of pelvic, abdominal or retroperitoneal tumor, which involves the small intestine, colon and rectum. Although the advances in radiotherapy technology have decreased the injury of adjacent tissues, 90% of the patients receiving radiotherapy have acute symptoms, the quality of life is affected due to gastrointestinal symptoms in 50% of patients, and 20%-40% of patients have moderate to severe symptoms. Based on the pathological stage, characteristics and clinical manifestations, RII can be divided into acute and chronic types, generally 3 to 6 months as the cutoff in clinical history. The main preventions of RII include reducing the radiation doses and narrowing the exposure fields. Acute RII is characterized by mucosal inflammation and self-limitation, and its treatment includes symptomatic and nutritional management. As the chronic ischemia and fibrosis in chronic RII are irreversible, bowel resection is the ideal treatment. The surgical indications for chronic RII are grade 3 and 4 intestinal injuries, including obstruction, bleeding, intestinal necrosis, perforation, and fistula. The current surgical procedure is definitive intestinal resection with stage I or II gastrointestinal reconstruction. The optimal time for definitive surgery is still controversial. Based on our experiences, 1 year after the end of radiation therapy is optimal. Under the circumstances of emergency surgery, severe malnutrition, abdominal infection, extensive intestinal injury, and abdominal adhesions that cannot be mobilized, ostomy and abdominal drainage are recommended, and definitive surgery can be considered after the return to enteral nutrition and extinction of intestinal inflammation. Preoperative setting of ureteral catheter, imaging assessment of colorectal position and iliac vascular injury, and preoperative nutritional support can reduce the risk of systemic complications effectively.

Patient reported outcomes in patients with head and neck cancer treated with concurrent chemoradiation with weekly versus bolus cisplatin.

Patient Reported Outcome (PRO) data comparing bolus (B-CP) with weekly (W-CP) cisplatin concurrent with radiation are lacking. We performed a retrospective study comparing PRO among 99 patients with head and neck radiation, 26% who received concurrent B-CP and 73% treated with W-CP. W-CP patients had a higher Charlson comorbidity index (CCI) (P = .004). There were no differences in median cisplatin dose, PROs, percutaneous endoscopic gastrostomy (PEG) dependence or hospitalization between arms. Patients with a greater decline in their self-reported dysphagia score were more often PEG dependent at the end of radiation therapy (P = .03). There was also a trend toward PEG dependence with a higher maximum dysphagia score and greater change in aspiration score (P = .06). The maximum decline in white cell count and absolute neutrophil count were greater in the W-CP group (P = .04, P = .01). Both B-CP and W-CP are well tolerated. PROs do not suggest a benefit to W-CP.

Age-stratified clinical performance and survival of patients with IDH-wildtype glioblastoma homogeneously treated by radiotherapy with concomitant and maintenance temozolomide

ObjectiveIsocitrate dehydrogenase (IDH)-wildtype glioblastomas are the most malignant glial tumours. Median survival is only 14–16 months after diagnosis, with patients aged ≥ 65 years reportedly showing worse outcome. This study aimed to further evaluate the prognostic role of age in a homogenously treated patient cohort.MethodsThe study includes 132 IDH-wildtype glioblastoma patients treated between 2013 and 2017 with open resection followed by radiotherapy with concomitant and maintenance temozolomide. Patients were dichotomized into a non-elderly (< 65 years) and an elderly (≥ 65 years) group. Extent of resection and the O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status were determined for each tumour. Clinical and radiological follow-up data were obtained at 6 weeks after the end of radiation therapy and thereafter in 3-month intervals. Progression-free survival (PFS) and overall survival (OS) were evaluated in univariate and multivariate cox regression analyses.ResultsThe elderly group consisted of 58 patients (median age: 70.5 years) and the non-elderly group of 74 patients (median age: 55 years). Median pre- and postoperative operative Karnofsky Performance Scale (KPS), Eastern Cooperative Oncology Group (ECOG) score and National Institutes of Stroke Scale (NIHSS) were not significantly different between the groups, but KPS and ECOG scores became significantly worse in the elderly group at 6 weeks after termination of radiation therapy. Neither PFS nor OS differed significantly between the age groups. Patients with MGMT promoter-methylated tumours survived longer.ConclusionElderly patients in good pre- and postoperative clinical conditions may show similar outcome as younger patients when treated according to standard of care. However, elderly patients may suffer more frequently from clinical deterioration following chemoradiotherapy. In both age groups, MGMT promoter methylation was linked to longer PFS and OS.

Dental status of patients with squamous cell carcinoma of the oropharyngeal region

Purpose of the study . To evaluate changes in the oral cavity in patients with squamous cell carcinoma of the oropharyngeal region after radiation therapy. Materials and methods. The study included 70 patients with oropharyngeal squamous cell carcinoma. All patients underwent external beam radiation therapy. We used dose fractionation mode: 5 fractions per week, single focal dose — 2G. The severity of oral mucositis was assessed using the RTOG evaluation scale. Results . Patients with carcinoma of the oropharyngeal region before the start of the main treatment had pathology of hard tooth tissues (CPU-14.62±1.08), gingival inflammation (PMA-41.71±4.98), periodontal inflammation (CPITN-2.54±0.62). After the end of radiation therapy, oral mucositis was detected in all patients (100%). We found changes in the negative side for all indicators of dental status indices compared to primary CPUs-15.26±0.90; CPITN-3.36±0.58; PMA-49.75±5.28 (p<0.05). Clinical signs of oral mucositis begin to appear as early as 7 days after the start of radiation therapy, RTOG=1,5. After 3 weeks, patients develop severe mucosal lesions with fibrinous plaque and severe pain syndrome (RTOG=3.0), requiring intensive drug therapy (p<0.05). Conclusion . In connection with the early appearance of post-radiation oral mucositis, preventive and therapeutic measures to improve the regeneration.

A Multicenter Phase 2 study of Hypofractionated Stereostatic Boost in Intermediate Risk Prostate Carcinoma: A 5-Year Analysis of the CKNO-PRO Trial

The aim of this analysis was to assess the 5-year tolerance and survival in patients undergoing hypofractionated stereotactic boost after external beam radiation therapy (EBRT) for intermediate-risk prostate cancer. Between August 2010 and April 2013, 76 patients with intermediate-risk prostate carcinoma were included in the study. A first course delivered 46 Gy using conventional fractionation. The second course delivered a boost of 18 Gy (3 × 6 Gy) within 10 days using stereotactic body radiation therapy (SBRT). Gastrointestinal and genitourinary toxicities were assessed according to the National Cancer Institute's Common Terminology Criteria for Adverse Events v4.0. Secondary outcome measures were overall, biochemical relapse-free, and relapse-free survival; prostate-specific antigen kinetics; and patient functional status (urinary and sexual) according to the International Index of Erectile Function and International Prostate Symptom Score questionnaires. Sixty patients (79%) were treated by CyberKnife and 16 (21%) by linear accelerator. Median follow-up was 62 months (range, 29-69). The cumulative incidence of genitourinary and gastrointestinal grade ≥2 toxicities at month 60 after the end of radiation therapy was 1.4% (95% confidence interval [CI], 0.1%-6.6%) and 9.3% (95% CI, 4.1%-17.1%), respectively. Biochemical relapse-free and relapse-free survival rates at 5 years were 87.4% (95% CI, 77.1%-93.2%) and 86.2% (95% CI, 75.8-92.3), respectively. The mean (standard deviation) prostate-specific antigen variation within 3 months and 5 years post-radiation therapy was -1.20 ng/mL/mo (0.79) and -1.30 ng/mL/y (1.05), respectively. There was no significant difference between the International Prostate Symptom quality of life score between inclusion and month 60. For the International Index of Erectile Function, there was a significant difference between inclusion and month 60 (P = .005), with a higher proportion of severe/noninterpretable disorders at 60 months. The results of the trial demonstrate that the EBRT and SBRT combination is well tolerated and yields good efficacy results. These data provide a good basis for comparing EBRT and brachytherapy boost to EBRT and SBRT boost in future prospective studies.

ES01.04 Immunotherapy, Radiotherapy and Chemotherapy Combination: A Potential New Standard?

ES01.04 Immunotherapy, Radiotherapy and Chemotherapy Combination: A Potential New Standard?

P14.126 radiation-induced optic neuropathy

Abstract BACKGROUND Optic neuropathy is an inflammation of the optic nerve leading to a rapidly progressive visual loss. Most frequent etiologies are multiple sclerosis, vasculitides, and infections. In the context of tumorous pathology, optic neuropathy can occur due to meningeal infiltration, tumoral compression, or antitumor therapeutics (radiation therapy, some targeted cancer therapies, and checkpoint inhibitors). In the current study, we examine radiation-induced optic neuropathy (RION), which is the most frequent among optic neuropathies caused by antitumor therapeutics. MATERIAL AND METHODS We present the cases of 3 patients who experienced RION. For each patient, we collected data on age, type of tumor, date and modalities of radiation-therapy, starting date of visual loss, ophthalmologic description, MRI images, treatment, and clinical and radiological evolution. RESULTS The three patients were aged 57 to 68 years old at the time of NORI. They had irradiation between 2013 and 2018. Two patients had proton therapy and one had whole brain irradiation. The visual loss occurred between seven and twelve months after the end of radiation therapy. In all patients the symptoms were bilateral and the loss of vision was rapidly worsened until culminating in almost total blindness. The MRI abnormalities were consistent with retrobulbar optic neuritis. The visual loss remained severe despite the treatment administered. High dose steroids had no clinical effect. Bevacizumab enabled a discrete subjective visual improvement in one patient, but a worsening of visual loss in another. Hyperbaric oxygen therapy had no clinical effect but was undertaken three months after the starting date of visual loss which is probably too late for efficiency. Interestingly one patient was treated with an anti-IL6 antibody (tocilizumab). It was administered in order to avoid fibrosis formation, which is the ultimate condition of the inflammatory process. The rationale is that radiation-induced opening of the bood-brain-barrier and destruction of endothelial and glial cells lead to reparation process through microglia activation. In-vitro studies showed an increased secretion of IL-6 (and other pro-inflammatory cytokines) by the activated microglia. Our patient could not experience benefit from tocilizumab, but the treatment was administered four months after the starting date of visual loss and fibrosis was probably already formed. CONCLUSION These cases are consistent with existing literature. The risk is mostly due to the total dose and dose per fraction of the irradiation and the prognosis is very poor with no efficient treatment at the present time. Anti-IL6 antibody could be an interesting treatment if administered at an early stage, but a future prospective clinical trial would be needed to clinically validate this hypothesis.

Fatal Radiation Pneumonitis: Literature Review and Case Series

PurposeFatal radiation pneumonitis is a rare event. In recent years, higher incidences of grade 5 pneumonitis have been reported. Based on 3 cases in our clinic, a literature review was performed to assess specific clinical features and risk factors for fatal pneumonitis. Methods and MaterialsThree patients with nonsmall cell lung cancer were treated with conventionally fractionated radiation therapy, 2 with volumetric modulated arc therapy and one with intensity modulated radiation therapy. All 3 patients had high volumes of 5 Gy in the total lung and contralateral lungs. Patients died of pneumonitis between 2 and 5 months after the end of radiation therapy. A literature review focused on grade 5 pneumonitis was performed for conventionally fractioned and stereotactic radiation therapy for lung cancer. ResultsPatients with grade 5 pneumonitis develop symptoms sooner than lower grade pneumonitis. Symptoms often do not respond to steroid treatment or return after steroid taper. Imaging features extend beyond the high dose area and involve the contralateral lung. Dosimetric risk factors include both low dose and high dose lung volumes. For patients undergoing stereotactic radiation therapy interstitial lung disease has been described as a risk factor. ConclusionsDespite decades of investigating radiation pneumonitis, the question of the optimum dose distribution in the lung, a large dose to a small volume versus a small dose to a large volume, is still unresolved. When both low and high dose lung volume constraints are followed, the risk for grade 5 pneumonitis has been shown to be low even with intensity modulated radiation therapy and concurrent chemotherapy. In addition to dose factors, underlying clinical and radiographic parameters play an important role for the development of grade 5 pneumonitis.

Lymphocyte Count Kinetics, Factors Associated with the End-of-Radiation-Therapy Lymphocyte Count, and Risk of Infection in Patients with Solid Malignant Tumors Treated with Curative-Intent Radiation Therapy

Lymphopenia has been associated with poor outcomes in patients with cancer. We sought to describe the lymphocyte kinetics in patients who received radiation therapy; to identify factors associated with the end-of-radiation-therapy (EoRT) lymphocyte count; and to determine the association of radiation therapy-induced lymphopenia with subsequent infection. Patients with solid malignant tumors treated at the Department of Oncology at Rigshospitalet, University of Copenhagen, Denmark, were included if they had received their first external beam radiation therapy with curative intent from January 2005 to December 2016 and had pretreatment and EoRT lymphocyte counts measured. Factors associated with the EoRT lymphocyte count were identified using regression analyses. The risk of subsequent infection was estimated using Cox proportional hazards regression. We included 3920 patients. More patients had lymphopenia (<1000 cells/μL) at EoRT than at pretreatment (67.1% vs 14.9%; P < .001). Patients who received schemes with higher intensities (equivalent dose in 2-Gy fractions [EQD2] >65 Gy) in shorter time (<25 days) had a higher predicted EoRT lymphocyte count than patients who received schemes delivering EQD2 of 50 to 65 Gy in 25 to 45 days (1439 cells/μL, 95% confidence interval [1293-1585] vs 784 [754-814]). Radiation to multiple sites and concomitant chemotherapy use, particularly platinum compounds versus none, were associated with a lower EoRT lymphocyte count (698 [655-742] vs 852 [833-870]; and 612 [565-659] vs 937 [909-964], respectively). Patients with EoRT lymphopenia grade ≥3 (<500 cells/μL) had a higher risk of infection in the 3 months after radiation therapy (hazard ratio, 2.15 [95% confidence interval, 1.53-3.02]; P < .001), compared with patients with an EoRT lymphocyte count >1000 cells/μL. The lymphocyte count declined during radiation therapy. Short duration schemes (<25 days), despite high total radiation dose (EQD2 >65 Gy), were associated with a higher EoRT lymphocyte count, whereas radiation to multiple sites and concomitant chemotherapy were associated with a lower count. EoRT lymphopenia was associated with an increased risk of infection.

EXPERIMENTAL MODELS OF RADIATION-INDUCED CYSTITIS IN LABORATORY ANIMALS (LITERATURE REVIEW)

Over the past 20 years, there has been a trend towards an increase in cancer morbidity in most states, in particular in the US and Russia, for a number of localizations, for example, prostate cancer, uterus, rectum and bladder cancer [6]. These localizations require radiation therapy at least as a part of multi-modal approach, or, quite often, as an independent method of treatment. However, frequency of acute radiation cystitis, according to current publications, after irradiation of the pelvis, remains high 5 to 80% for 100 days)/ Frequency of late radiation complications, which can occur from 3 months after the end of radiation therapy up to 20 years ranges from 5 to 50% [1, 2, 4, 5, 8]. There is a need for randomized, controlled trials to determine standards in the treatment of this formidable complication of radiation therapy. Models of radiation-induced cystitis in animals are being developed to study possible ways of treatmentб but they are either not easy to reproduce, do not imitate treatment regimes in humans to full extent, or cause unnecessary suffering to experimental animals [18]. Authors suggested new model of radiation-induced cystitisclosely resembling regimes used in real patients [7].

Abstract P3-12-04: Analysis of radiation dose to the shoulder by treatment technique and correlation with patient reported outcomes in patients receiving regional nodal irradiation

Abstract Background: Shoulder/arm morbidity is a late complication of breast cancer treatment. Postmastectomy radiation therapy (PMRT)/regional nodal irradiation (RNI) increases dose to the muscles and soft tissues of the shoulder and upper neck and back. Most patients are treated with 3D conformal radiation therapy (3DCRT) or Intensity modulated radiation therapy (IMRT). Here, we set to analyze the impact of 3DCRT vs. IMRT on radiation dose to the shoulder, and to retrospectively explore the relationship of treatment technique on long term patient-reported outcomes in the subset of patient who had completed the quick Disabilities of the Arm, Shoulder, and Hand (q-DASH) questionnaire. Materials/Methods: We identified consecutive patients in our department treated with PMRT/RNI for curative intent from 2013-2016. We excluded patients treated for recurrent disease, those with metastatic disease, and those with unresected disease in the supraclavicular (SCV) fossa and/or axillary apex requiring a radiation boost to that area. We contoured the shoulder as all of the muscles/soft tissue/bone from 2 cm above the ipsilateral SCV planning target volume (PTV) to the cranial aspect of the breast or chestwall PTV. No planning constraints were set for the shoulder since this was retrospectively contoured. We used the dose volume histogram to determine the volume of shoulder receiving at least 5 Gy, 10 Gy,...,50 Gy (V5-V50, respectively). We identified patients that completed a q-DASH questionnaire ≥6 months from the end of PMRT/RNI. Descriptive statistics were used to summarize the shoulder dose and q-DASH values. Differences between groups were assessed by the t-test or chi-square test with p&amp;lt;0.05 considered significant. Results: We found 237 patients treated with PMRT/RNI with median age of 52 y (IQR 44-60 y), 75% treated with mastectomy, 85% had axillary lymph node dissection (ALND), median of 18 nodes removed (IQR 12-26). All patients received 50 Gy/25 fractions. A total of 68 patients (28.7%) were treated with IMRT. IMRT significantly reduced the V20-V50 to the shoulder vs. 3DCRT (e.g., V45Gy=21.7 mL vs. 208.4 mL, p&amp;lt;0.0001). Of the 237 patients, 66 had completed a q-DASH at least 6 months from the end of radiation therapy (median, 14.5 months). Patients that completed the q-DASH vs. not were similar in age (p=0.29), number of nodes removed (p=0.17), use of ALND (p=0.13), use of chemotherapy (p=0.49) and use of mastectomy (p=0.22). The median (IQR) and mean (SD) q-DASH were 20.5 (6.8-38.6) and 24.3 (20.2) for all patients; 20.5 (9.1-38.6) and 24.1 (19.4) for the 53 mastectomy patients; 18.2 (4.5-45.5) and 25.2 (24.2) for the 13 lumpectomy patients. Most patients (N=49) were treated with 3DCRT. Compared to patients treated with 3DCRT, IMRT patients had a trend towards lower q-DASH mean scores: 16.9 vs. 26.9, p=0.077. Conclusion: In summary, we found that IMRT reduces radiation dose to the shoulder and is associated with a trend towards reduced q-DASH scores at least 6 months after PMRT/RNI in a subset of our cohort. These results support prospective evaluation of IMRT as a technique to reduce shoulder morbidity in breast cancer patients receiving PMRT/RNI. Citation Format: Bazan JG, Dicostanzo D, Hock K, Healy E, Beyer S, White JR. Analysis of radiation dose to the shoulder by treatment technique and correlation with patient reported outcomes in patients receiving regional nodal irradiation [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-12-04.

Chronic radiation enteritis

Radiation enteritis is an iatrogenic disease of the intestines caused by radiation therapy. Two entities, chronic and acute radiation enteritis, are described. The acute symptoms (abdominal pain, loss of appetite, diarrhea) develop within the first hours or days after radiation therapy and can be treated medically. Chronic radiation enteritis leads to a chronic sub-obstructive and/or malabsorption syndrome developing at least two months after the end of radiation therapy. Cases occurring 30 post-radiation are reported. Treatment is surgical with extended resection of all involved elements of the digestive tract and ileocolonic anastomosis in healthy zones. The diagnosis is confirmed by the anatomopathology report of fibrous intestinal lesions associated with obliterating arterial lesions.

Evaluation of Quality of Life and Psychological Response in Recurrent and Metastatic Tumors Treated with Palliative Radiotherapy

Objective: We evaluated the effects of palliative radiotherapy for cancer recurrence or metastasis on patient QOL and psychophysiology. Materials and Methods: Sixty seven patients who received palliative radiotherapy between 2014 and 2015 were enrolled. Patient diseases were bone metastasis in 51 patients, lymph node metastasis in 7 patients, brain metastasis in 2 patients, local recurrence in 3 patients, and others in 4 patients. Median irradiated dose was 30 Gy in 10 fractions for palliative radiotherapy. We used the questionnaires EORTC-QLQ-C30 and EORTC-QLQ-C15-PAL to evaluate patient QOL and the Hospital Anxiety and Depression Scale to evaluate patient mental healthcare at the start and at the end of radiotherapy. Results: As compared to scores at the start of radiotherapy, at the end of radiotherapy, NRS and face scale significantly decreased. On the other hand, Eastern Cooperative Oncology Group Performance Status did not show any changes during palliative radiotherapy. In functional scales, average scores of RF2 and EF also improved. In symptom scales, average scores of FA, PA, and SL improved. In bone metastasis group, global health status/QOL, PA, and SL significantly improved. There was relationship between anxiety improvement and QOL improvement after palliative radiotherapy. Nausea and vomiting scores of EORTC-QLQ-C15-PAL were associated with the irradiated volume of palliative radiotherapy for pelvic region. Conclusion: Patient QOL of was improved by palliative radiotherapy regardless of PS. The possibility of palliative radiotherapy having a positive influence on patient psychophysiology was also suggested in younger age.

The experience of breast cancer survivors’ participation in important activities during and after treatments

Introduction This study compares breast cancer survivors’ experiences of participating in activities important to them, both during and after breast cancer treatment. Method Eight survivors between the ages of 41 and 60 years with Stage I, II, or III breast cancer who had been treated consecutively with surgery, chemotherapy, and radiation therapy were recruited for the study. Participants completed the Activity Card Sort-modified and a semi-structured interview at the end of radiation therapy and 6 months post treatment. Findings Interpretative phenomenological analysis was used to analyze the transcripts. The themes identified differed at each time point. At the end of treatment, themes were (a) personal and treatment stress changes activity participation, (b) strategies increase activity participation, (c) fatigue, fear of infection or other side effects reduces activity participation, (d) family and friends assist with completing activities, and (e) plans for participating in activities after treatment ends. At 6 months post treatment, themes were: (a) emotions influence activity participation, (b) activities after cancer have changed, and (c) side effects influence activity participation. Conclusions During treatment, survivors may be focusing more on “needed” activities; later on, survivors may want to participate in leisure activities, including ones that they have been wanting to pursue.