ABSTRACT
BACKGROUND: For cancer patient populations worldwide, the synchronous scale-up of diagnostics and treatments yields meaningful gains in survival and quality of life. Among advanced cancer therapies, radiotherapy (RT) and theranostics are key to achieving practical, high-quality, and personalized precision medicine - targeting disease manifestations of individual patients and broad populations, alike. Aiming to learn from one another across different world regions, the six country vignettes presented here depict both challenges and victories in de novo establishment or improvement of RT and theranostics infrastructure. METHODS: The International Atomic Energy Agency (IAEA) convened global RT and theranostics experts from diverse world regions and contexts to identify relevant challenges and report progress in their own six countries: Belgium, Brazil, Costa Rica, Jordan, Mongolia, and South Africa. These accounts are collated, compared, and contrasted herein. RESULTS: Common challenges persist which could be more strategically assessed and addressed. A quantifiable discrepancy entails personnel. The estimated radiation oncologists (ROs), nuclear medicine physicians (NMPs), and medical physicists (MPs for RT and nuclear medicine) per million inhabitants in the six collective countries respectively range between 2.69-38.00 ROs, 1.00-26.00 NMPs, and 0.30-3.45 MPs (Table 1), reflecting country-to-country inequities which largely match World Bank country-income stratifications. CONCLUSION: Established goals for RT and nuclear medicine advancement worldwide have proven elusive. The pace of progress could be hastened by enhanced approaches such as more sustainably phased implementation; better multinational networking to share lessons learned; routine quality and safety audits; as well as capacity building employing innovative, resource-sparing, cutting-edge technologic approaches. Bodies such as ministries of health, professional societies, and the IAEA shall serve critical roles in convening and coordinating more innovative RT and theranostics translational research, including expanding nuanced global database metrics to inform, reach, and potentiate milestones most meaningfully. POLICY SUMMARY: Aligned with WHO 25×25 NCDs target; WHA70.12 and WHA76.5 resolutions.
Subject(s)
Neoplasms , Humans , Neoplasms/radiotherapy , South Africa , Jordan , Brazil , Costa Rica , Precision Medicine , Radiotherapy , Theranostic NanomedicineABSTRACT
OBJECTIVE: Initiating postoperative radiotherapy (PORT) within 6 weeks (42 days) of surgery is the first and only Commission on Cancer (CoC) approved quality metric for head and neck squamous cell carcinoma (HNSCC). No study has systematically reviewed nor synthesized the literature to establish national benchmarks for delays in starting PORT. DATA SOURCES: Following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, we performed a systematic review of PubMed, Scopus, and CINAHL. REVIEW METHODS: Studies that described time-to-PORT or PORT delays in patients with HNSCC treated in the United States after 2003 were included. Meta-analysis of proportions and continuous measures was performed on nonoverlapping datasets to examine the pooled frequency of PORT delays and time-to-PORT. RESULTS: Thirty-six studies were included in the systematic review and 14 in the meta-analysis. Most studies utilized single-institution (n = 17; 47.2%) or cancer registry (n = 16; 44.4%) data. Twenty-five studies (69.4%) defined PORT delay as >6 weeks after surgery (the definition utilized by the CoC and National Comprehensive Cancer Network Guidelines), whereas 4 (11.1%) defined PORT delay as a time interval other than >6 weeks, and 7 (19.4%) characterized time-to-PORT without defining delay. Meta-analysis revealed that 48.6% (95% confidence interval [CI], 41.4-55.9) of patients started PORT > 6 weeks after surgery. Median and mean time-to-PORT were 45.8 (95% CI, 42.4-51.4 days) and 47.4 days (95% CI, 43.4-51.4 days), respectively. CONCLUSION: Delays in initiating guideline-adherent PORT occur in approximately half of patients with HNSCC. These meta-analytic data can be used to set national benchmarks and assess progress in reducing delays.
Subject(s)
Head and Neck Neoplasms , Humans , United States , Squamous Cell Carcinoma of Head and Neck , Radiotherapy, Adjuvant , Head and Neck Neoplasms/radiotherapy , Head and Neck Neoplasms/surgeryABSTRACT
BACKGROUND: Aligned with the NCCN Clinical Practice Guidelines in Oncology for Head and Neck Cancers, in November 2021 the Commission on Cancer approved initiation of postoperative radiation therapy (PORT) within 6 weeks of surgery for head and neck cancer (HNC) as its first and only HNC quality metric. Unfortunately, >50% of patients do not commence PORT within 6 weeks, and delays disproportionately burden racial and ethnic minority groups. Although patient navigation (PN) is a potential strategy to improve the delivery of timely, equitable, guideline-adherent PORT, the national landscape of PN for this aspect of care is unknown. MATERIALS AND METHODS: From September through November 2022, we conducted a survey of health care organizations that participate in the American Cancer Society National Navigation Roundtable to understand the scope of PN for delivering timely, guideline-adherent PORT for patients with HNC. RESULTS: Of the 94 institutions that completed the survey, 89.4% (n=84) reported that at least part of their practice was dedicated to navigating patients with HNC. Sixty-eight percent of the institutions who reported navigating patients with HNC along the continuum (56/83) reported helping them begin PORT. One-third of HNC navigators (32.5%; 27/83) reported tracking the metric for time-to-PORT at their facility. When estimating the timeframe in which the NCCN and Commission on Cancer guidelines recommend commencing PORT, 44.0% (37/84) of HNC navigators correctly stated ≤6 weeks; 71.4% (60/84) reported that they did not know the frequency of delays starting PORT among patients with HNC nationally, and 63.1% (53/84) did not know the frequency of delays at their institution. CONCLUSIONS: In this national landscape survey, we identified that PN is already widely used in clinical practice to help patients with HNC start timely, guideline-adherent PORT. To enhance and scale PN within this area and improve the quality and equity of HNC care delivery, organizations could focus on providing better education and support for their navigators as well as specialization in HNC.
Subject(s)
Head and Neck Neoplasms , Patient Navigation , Humans , Ethnicity , Minority Groups , Head and Neck Neoplasms/therapy , Combined Modality TherapyABSTRACT
PURPOSE: This study aims at determining the parameter values of three normal tissue complication probability (NTCP) models for the contralateral parotid gland, contralateral submandibular gland (SMG) and contralateral salivary glands regarding the endpoint of xerostomia 6-24 months after radiotherapy for oropharynx cancer. METHODS: The treatment and outcome data of 231 patients with favorable risk, HPV-associated oropharyngeal squamous cell carcinoma are analyzed. 60 Gy intensity modulated radiotherapy was delivered to all the patients. The presence and severity of xerostomia was recorded (pre- and post- radiotherapy) by the PRO-CTCAE and the CTCAE scoring systems. In both scoring systems, patients with a change in symptom severity (from baseline) of ≥ 2 were considered responders. RESULTS: Xerostomia was observed in 61.3 %, 39.2 %, 28.6 % and 27.0 % of the patients based on the PRO-CTCAE scoring system at 6-, 12-, 18- and 24-months post-RT, respectively. The AUCs of the contralateral salivary glands ranged between 0.58-0.64 in the LKB model with the gEUD ranging between 20.3 Gy and 24.7 Gy. CONCLUSIONS: Based on the PRO-CTCAE scores, mean dose < 22 Gy, V50 < 10 % for the contralateral salivary glands and mean dose < 18 Gy, V45 < 10 % for the contralateral parotid were found to significantly reduce by a factor of 2-3 the risk for radiation induced xerostomia that is observed at 6-24 months post-RT, respectively. Also, gEUD < 22 Gy to the contralateral salivary glands and < 18 Gy to the contralateral parotid was found to significantly reduce the risk for radiation induced xerostomia that is observed at 6-24 months post-RT by 2.0-2.3 times.
Subject(s)
Head and Neck Neoplasms , Oropharyngeal Neoplasms , Radiotherapy, Intensity-Modulated , Xerostomia , Humans , Radiotherapy Dosage , Xerostomia/etiology , Xerostomia/diagnosis , Xerostomia/pathology , Oropharyngeal Neoplasms/radiotherapy , Parotid Gland , Radiotherapy, Intensity-Modulated/adverse effects , Head and Neck Neoplasms/complications , ProbabilityABSTRACT
BACKGROUND: Patients with locally advanced head and neck squamous cell cancer (HNSCC) are treated with surgery followed by adjuvant (chemo) radiotherapy or definitive chemoradiation, but recurrence rates are high. Immune checkpoint blockade improves survival in patients with recurrent/metastatic HNSCC; however, the role of chemo-immunotherapy in the curative setting is not established. METHODS: This phase 2, single-arm, multicenter study evaluated neoadjuvant chemo-immunotherapy with carboplatin, nab-paclitaxel, and durvalumab in patients with resectable locally advanced HNSCC. The primary end point was a hypothesized pathologic complete response rate of 50%. After chemo-immunotherapy and surgical resection, patients received study-defined, pathologic risk adapted adjuvant therapy consisting of either durvalumab alone (low risk), involved field radiation plus weekly cisplatin and durvalumab (intermediate risk), or standard chemoradiation plus durvalumab (high risk). RESULTS: Between December 2017 and November 2021, 39 subjects were enrolled at three centers. Oral cavity was the most common primary site (69%). A total of 35 of 39 subjects underwent planned surgical resection; one subject had a delay in surgery due to treatment-related toxicity. The most common treatment-related adverse events were cytopenias, fatigue, and nausea. Post treatment imaging demonstrated an objective response rate of 57%. Pathologic complete response and major pathologic response were achieved in 29% and 49% of subjects who underwent planned surgery, respectively. The 1-year progression-free survival was 83.8% (95% confidence interval, 67.4%-92.4%). CONCLUSIONS: Neoadjuvant carboplatin, nab-paclitaxel, and durvalumab before surgical resection of HNSCC were safe and feasible. Although the primary end point was not met, encouraging rates of pathologic complete response and clinical to pathologic downstaging were observed.
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Purpose: Pretreatment quality assurance (QA) of treatment plans often requires a high cognitive workload and considerable time expenditure. This study explores the use of machine learning to classify pretreatment chart check QA for a given radiation plan as difficult or less difficult, thereby alerting the physicists to increase scrutiny on difficult plans. Methods and Materials: Pretreatment QA data were collected for 973 cases between July 2018 and October 2020. The outcome variable, a degree of difficulty, was collected as a subjective rating by physicists who performed the pretreatment chart checks. Potential features were identified based on clinical relevance, contribution to plan complexity, and QA metrics. Five machine learning models were developed: support vector machine, random forest classifier, adaboost classifier, decision tree classifier, and neural network. These were incorporated into a voting classifier, where at least 2 algorithms needed to predict a case as difficult for it to be classified as such. Sensitivity analyses were conducted to evaluate feature importance. Results: The voting classifier achieved an overall accuracy of 77.4% on the test set, with 76.5% accuracy on difficult cases and 78.4% accuracy on less difficult cases. Sensitivity analysis showed features associated with plan complexity (number of fractions, dose per monitor unit, number of planning structures, and number of image sets) and clinical relevance (patient age) were sensitive across at least 3 algorithms. Conclusions: This approach can be used to equitably allocate plans to physicists rather than randomly allocate them, potentially improving pretreatment chart check effectiveness by reducing errors propagating downstream.
ABSTRACT
PURPOSE: Head and neck cancer (HNC) treatment results in morbidity impacting quality of life (QOL) in survivorship. This analysis evaluated changes in oral health-related QOL (OH-QOL) up to 2 years after curative intent radiation therapy (RT) for HNC patients and factors associated with these changes. METHODS: 572 HNC patients participated in a multicenter, prospective observational study (OraRad). Data collected included sociodemographic, tumor, and treatment variables. Ten single-item questions and 2 composite scales of swallowing problems and senses problems (taste and smell) from a standard QOL instrument were assessed before RT and at 6-month intervals after RT. RESULTS: The most persistently impacted OH-QOL variables at 24 months included: dry mouth; sticky saliva, and senses problems. These measures were most elevated at the 6-month visit. Aspects of swallowing were most impacted by oropharyngeal tumor site, chemotherapy, and non-Hispanic ethnicity. Problems with senses and dry mouth were worse with older age. Dry mouth and sticky saliva increased more among men and those with oropharyngeal cancer, nodal involvement, and use of chemotherapy. Problems with mouth opening were increased by chemotherapy and were more common among non-White and Hispanic individuals. A 1000 cGy increase in RT dose was associated with a clinically meaningful change in difficulty swallowing solid food, dry mouth, sticky saliva, sense of taste, and senses problems. CONCLUSIONS: Demographic, tumor, and treatment variables impacted OH-QOL for HNC patients up to 2 years after RT. Dry mouth is the most intense and sustained toxicity of RT that negatively impacts OH-QOL of HNC survivors. GOV IDENTIFIER: NCT02057510; first posted February 7, 2014.
Subject(s)
Head and Neck Neoplasms , Oropharyngeal Neoplasms , Xerostomia , Male , Humans , Quality of Life , Head and Neck Neoplasms/radiotherapy , Saliva , Xerostomia/epidemiology , Xerostomia/etiologyABSTRACT
OBJECTIVES: Stereotactic body radiation therapy (SBRT) can improve therapeutic ratios and patient convenience, but delivering higher doses per fraction increases the potential for patient harm. Incident learning systems (ILSs) are being increasingly adopted in radiation oncology to analyze reported events. This study used an ILS coupled with a Human Factor Analysis and Classification System (HFACS) and barriers management to investigate the origin and detection of SBRT events and to elucidate how safeguards can fail allowing errors to propagate through the treatment process. METHODS: Reported SBRT events were reviewed using an in-house ILS at 4 institutions over 2014-2019. Each institution used a customized care path describing their SBRT processes, including designated safeguards to prevent error propagation. Incidents were assigned a severity score based on the American Association of Physicists in Medicine Task Group Report 275. An HFACS system analyzed failing safeguards. RESULTS: One hundred sixty events were analyzed with 106 near misses (66.2%) and 54 incidents (33.8%). Fifty incidents were designated as low severity, with 4 considered medium severity. Incidents most often originated in the treatment planning stage (38.1%) and were caught during the pretreatment review and verification stage (37.5%) and treatment delivery stage (31.2%). An HFACS revealed that safeguard failures were attributed to human error (95.2%), routine violation (4.2%), and exceptional violation (0.5%) and driven by personnel factors 32.1% of the time, and operator condition also 32.1% of the time. CONCLUSIONS: Improving communication and documentation, reducing time pressures, distractions, and high workload should guide proposed improvements to safeguards in radiation oncology.
Subject(s)
Radiation Oncology , Radiosurgery , Humans , Health Facilities , LearningABSTRACT
PURPOSE: Localized amyloidosis is a condition characterized by deposits of fibrillary proteins confined to a single organ. The most common subtype is amyloid light chain amyloidosis, which is caused by secretion of amyloidogenic light chain by a monoclonal population of plasma cells. We present a review and discussion of the literature in the context of a case presentation of localized amyloid light chain amyloidosis of the nasopharynx treated with radiation alone. METHODS AND MATERIALS: We reviewed literature relevant to this topic from 1970 to the present. Relevant studies, reports, and articles were summarized in table form. RESULTS: Surgical resection has historically been the primary therapeutic modality for these patients, with radiation being reserved for recurrent lesions or for those unfit for surgery. Although the data are limited to small retrospective series, radiation has been shown to provide good control with mild toxicity that is as good as or better than surgery. Doses range from 20 to 45 Gy, conventionally fractionated. There is no known risk of progression to systemic disease without local therapy. CONCLUSIONS: We recommend local therapy for symptomatic patients after systemic disease has been excluded. We generally recommend radiation in the setting of recurrent lesions, unacceptable toxicity with surgery, poor surgical candidates, and as the initial modality in select patients (elderly individuals with bothersome but nonobstructive lesions).
Subject(s)
Amyloidosis , Humans , Aged , Retrospective Studies , Amyloidosis/radiotherapyABSTRACT
Purpose: To determine the relationship between mean oral cavity (OC) dose (treated as a singular organ at risk) to patient reported xerostomia and dysgeusia. In addition, we will examine the relationship between oral cavity substructure doses to patient reported xerostomia and dysgeusia. All patients were treated in the setting of deintensification (60 Gy). Methods and Materials: In the study, 184 and 177 prospectively enrolled patients for de-escalated chemoradiotherapy (CRT) for human papillomavirus (HPV)-positive oropharyngeal cancer submitted PROs at 6 and 12 months, respectively using Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events questionnaire. Patient's OC consisting of the following substructures were segmented: oral tongue, base of tongue, floor of mouth, hard and soft palate, cheek mucosa, and upper and lower lip mucosa. Ordinal logistic regression (no/mild vs moderate vs severe/very severe symptoms) was used to compare organs at risk dosimetry to patient reported xerostomia and dysgeusia at 6 and 12 months. Multivariate ordinal logistic regression models were generated. Results: Mean dose to the contralateral parotid (P = .04), OC (P = .04), and baseline patient reported xerostomia (P = .009) were significantly associated with xerostomia severity at 6 months. Only baseline xerostomia (P = .02) and mean dose to the contralateral submandibular gland (P = .0001) were significantly associated with xerostomia severity at 12 months. The only significant factor related to dysgeusia at either time point was mean dose to the OC at 12 months (P = .009). On examining substructures, the mean dose to the floor of mouth was implicated for the dose relationship to 6-month xerostomia (P = .04), and the oral tongue was found to be implicated for the relationship for 12-month dysgeusia (P = .04). Conclusions: The mean dose to the OC was found to relate to xerostomia symptoms at 6 months post-CRT and dysgeusia symptoms at 12 months post-CRT. The mean dose to the floor of mouth and oral tongue appeared to drive this relationship for xerostomia and dysgeusia symptoms, respectively. This work suggests the floor of mouth and oral tongue should be prioritized during planning over the rest of the OC. The effect of OC dose relative to other salivary structures for xerostomia appeared to depend on time post-CRT.
Subject(s)
Stroke , Humans , Radiotherapy Dosage , Radiotherapy, Adjuvant , Retrospective Studies , Stroke/epidemiology , Stroke/etiologyABSTRACT
Chart checking is a time intensive process with high cognitive workload for physicists. Previous studies have partially automated and standardized chart checking, but limited studies implement data-driven approaches to reduce cognitive workload for quality assurance processes. This study aims to evaluate feature selection methods to improve the interpretability and transparency of machine learning models in predicting the degree of difficulty for a pretreatment physics chart check. We compare chi-square, mutual information, feature importance thresholding, and greedy feature selection for four different classifiers. Random forest has the highest performance with SMOTE oversampling using mutual information for feature selection (accuracy 84.0%, AUC 87.0%, precision 80.0%, recall 80.0%). This study demonstrates that feature selection methods can improve model interpretability and transparency.
Subject(s)
Radiation Oncology , Engineering , Machine LearningABSTRACT
PURPOSE: To assess the impact of prospectively sparing the parotid ducts via MRI sialography on patient reported xerostomia for those receiving definitive radiotherapy (RT) for oropharyngeal squamous cell carcinoma. METHODS AND MATERIALS: Thirty-eight patients with oropharynx cancer to be treated with definitive RT underwent pre-treatment MRI sialograms to localize their parotid ducts. The parotid ducts were maximally spared during treatment planning. Patients reported symptoms (PRO-CTCAE and QLQ-H&N35) were collected at 6 and 12 months post-RT and compared to a historical cohort who underwent conventional parotid gland mean dose sparing. Regression models were generated using parotid and submandibular gland doses with and without incorporating the dose to the parotid ducts to determine the impact of parotid duct dose on patient reported xerostomia. RESULTS: At 6 months post-RT, 12/26 (46%) patients reported ≥moderate xerostomia when undergoing parotid ductal sparing compared to 43/61 (70%) in the historical cohort (p = 0.03). At 12 months post-RT, 8/22 (36%) patients reported ≥moderate xerostomia when undergoing parotid ductal sparing compared to 34/68(50%) in the historical cohort (p = 0.08). Using nested logistic regression models, the mean parotid duct dose was found to significantly relate to patient reported xerostomia severity at 6 months post-RT (p = 0.04) and trended towards statistical significance at 12 months post-RT (p = 0.09). At both 6 and 12 months post-RT, the addition of mean parotid duct dose significantly improved model fit (p < 0.05). CONCLUSIONS: MRI sialography guided parotid duct sparing appears to reduce the rates of patient-reported xerostomia. Further, logistic regression analysis found parotid duct dose to be significantly associated with patient reported xerostomia. A significant improvement in model fit was observed when adding mean parotid duct dose compared to models that only contain mean parotid gland dose and mean contralateral submandibular gland dose.
Subject(s)
Head and Neck Neoplasms , Xerostomia , Head and Neck Neoplasms/diagnostic imaging , Head and Neck Neoplasms/radiotherapy , Humans , Magnetic Resonance Imaging , Parotid Gland/diagnostic imaging , Patient Reported Outcome Measures , Prospective Studies , Sialography , Xerostomia/diagnosis , Xerostomia/etiology , Xerostomia/prevention & controlABSTRACT
OBJECTIVE: The aim of this study was to determine whether quantitative methods could aid in the evaluation of post-treatment head and neck scans, particularly taking human papillomavirus status into account. METHODS: Clinical readings of positron emission tomography/computed tomography scans as well as standardized uptake value (SUV)max (and other metrics) of nodes visible on PET conducted on a total of 172 patients with head and neck squamous cell cancer were examined. Locoregional recurrence at 2 years was assessed. In total 88 of these patients had close enough follow-up to determine whether individual nodes were positive or negative, and 233 nodes on these patients were compared to surgical pathology notes or follow-up (if no path was available). RESULTS: General negative predictive value (NPV) of complete response was 93% and an equivocal response was 89%; focusing on nodal recurrence, NPV was found to be 97% and positive predictive value (PPV) 46% if equivocal reads were treated as negative and NPV 98% and PPV 16% if equivocal reads were treated as positive. Using SUVmax of the hottest node with a cutoff of 3.4 gave NPV 97% and PPV 26%; a direct re-read (using 2 observers) gave NPV 98% and PPV 32% if equivocal reads were treated as negative, and NPV 99% and PPV 18% if equivocal reads were treated as positive. Using other first-order radiomics data such as SD and skewness did not improve this. CONCLUSIONS: Quantitative data such as SUVmax does not show additional value over qualitative evaluation of response to chemoradiation in head and neck tumors.
Subject(s)
Head and Neck Neoplasms , Neoplasm Recurrence, Local , Chemoradiotherapy , Fluorodeoxyglucose F18 , Head and Neck Neoplasms/diagnostic imaging , Humans , Neoplasm Recurrence, Local/diagnostic imaging , Positron Emission Tomography Computed Tomography/methods , Positron-Emission Tomography/methods , Radiopharmaceuticals , Retrospective Studies , Squamous Cell Carcinoma of Head and Neck/diagnostic imagingABSTRACT
OBJECTIVE: To compare oncologic outcomes in sinonasal squamous cell carcinoma (SNSCC) treated with standard of care (SOC) definitive therapy, consisting of surgery or chemoradiotherapy, vs induction therapy followed by definitive therapy. STUDY DESIGN: Retrospective review. SETTING: Academic tertiary care hospital. METHODS: The medical records of patients with biopsy-proven SNSCC treated between 2000 and 2020 were reviewed for demographics, tumor characteristics, staging, treatment details, and oncologic outcomes. Patients were matched 1-to-1 by age, sex, and cancer stage according to treatment received. Time-to-event analyses were conducted. RESULTS: The analysis included 26 patients with locally advanced SNSCC who received either induction therapy (n = 13) or SOC (n = 13). Baseline demographics, Charlson Comorbidity Index, and median follow-up time were well balanced. Weekly cetuximab, carboplatin, and paclitaxel were the most common induction regimen utilized. Tolerance and safety to induction were excellent. Objective responses were observed in 11 of 13 patients receiving induction. No difference in disease-free survival was found between the induction and SOC groups at 1 or 3 years. However, when compared with SOC, induction therapy resulted in significant improvement in overall survival at 2 years (100% vs 65.3%, P = .043) and 3 years (100% vs 48.4%, P = .016) following completion of definitive therapy. Two patients in the SOC group developed metastatic disease, as compared with none in the induction group. CONCLUSIONS: Induction therapy was safe and effective. When compared with SOC, induction therapy improved 3-year overall survival.
Subject(s)
Induction Chemotherapy , Paranasal Sinus Neoplasms , Humans , Standard of Care , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Squamous Cell Carcinoma of Head and Neck/pathology , Paranasal Sinus Neoplasms/pathology , Chemoradiotherapy , Paclitaxel , Neoplasm StagingSubject(s)
Head and Neck Neoplasms , Induction Chemotherapy , Albumins , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Carboplatin/therapeutic use , Cetuximab/therapeutic use , Follow-Up Studies , Head and Neck Neoplasms/drug therapy , Humans , Paclitaxel/therapeutic use , Squamous Cell Carcinoma of Head and Neck/drug therapyABSTRACT
PURPOSE: This study aimed to prospectively assess dosimetric and clinical effects of treatment planners having a priori knowledge of the maximum achievable dose sparing for organs at risk (OARs) for patients with oropharynx cancer receiving intensity modulated radiation therapy (RT). METHODS AND MATERIALS: We examined patients with oropharynx cancer who were treated in prospective clinical trials between February 2012 and April 2019 at our institution. A tool generating estimates of maximum achievable dose sparing for OARs (feasibility dose-volume histogram [FDVH]) was used clinically starting July 2016. Patients were divided into 2 cohorts: Before (ie, baseline) and after (ie, FDVH-guided) FDVH. Doses received by various OARs were compared with those estimated to be achievable per FDVH, and that difference was defined as the excess of feasible dose (EFD). Patient-reported outcome (PRO) questionnaires were completed at 3, 6, and 12 months after treatment. The baseline and FDVH-guided cohorts were compared in terms of EFD, plan quality metrics, and post-RT PRO assessments. RESULTS: A total of 139 patients were included in the analysis (60 in the baseline cohort, 79 in the FDVH-guided cohort). The FDVH-guided cohort had lower EFD to the contralateral parotid by 4.1 Gy, the ipsilateral parotid by 10.6 Gy, the larynx by 4.3 Gy, the oral cavity by 1.5 Gy, and the contralateral submandibular gland by 0.4 Gy. Plan quality metrics were similar between the cohorts. Less variation of EFD was seen in the FDVH-guided cohort for the parotid glands and contralateral submandibular gland (P < .05). The average post-RT PROs were better in the FVHD cohort versus baseline (particularly at the 6-month timepoint for dry mouth frequency, sticky saliva, meal enjoyment, severity of pain, and Eating Assessment Tool 10 composite [swallowing]; P < .05). CONCLUSIONS: Use of FDVH was associated with improved and less variable OAR sparing for clinically delivered plans. FDVH-guided patients had improved PROs compared with baseline with a variety of outcomes significantly improved at 6 months after treatment.