Data from a local quality registry are used to model the risk of late xerostomia after radiotherapy for head and neck cancer, based on dosimetric- and clinical variables. Strengths and weaknesses of using quality registry data are explored. Head and neck cancer patients treated with radiotherapy at Karolinska University hospital are entered into a quality registry at routine follow up, recording morbidity according to a modified RTOG/LENT-SOMA scale. Other recorded parameters are performance status, age, gender, tumor location, tumor stage, smoking status, chemotherapy and radiotherapy data, including prescribed dose and organ-at-risk dose. Most patients are entered at several time points, but at variable times after treatment. Xerostomia was modeled based on follow-up data from January 2014 to October 2018, resulting in 753 patients. Two endpoints were considered: maximum grade ≥2 (XERG≥2) or grade ≥3 (XERG≥3) late xerostomia. Univariate Cox regression was used to select variables for two multivariate models for each endpoint, one based on the mean dose to the total parotid volume (Dtot) and one based on the mean dose to the contralateral parotid (Dcontra). Cox regression allows the estimation of the risk of xerostomia at different time points; models were presented visually as nomograms estimating the risk at 9, 12 and 24 months respectively. The toxicity rates were 366/753 (49%) for XERG≥2 and 40/753 (5.3%) for XERG≥3. The multivariate models included several variables for XERG≥2, and dose, concomitant chemotherapy and age were included for XERG≥3. Induction chemotherapy and an increased number of fractions per week showed a protective effect regarding XERG≥2. However, since the causality of these relationships have limited support from previous studies, alternative models without these variables were also presented. The models based on the mean dose to the total parotid volume and the contralateral parotid alone were very similar. Late xerostomia after radiotherapy can be modelled with reasonable predictive power based on registry data; models are presented for different endpoints highly relevant in clinical practice. However, the risk of modeling indirect relationships, given the unavoidably heterogeneous and uncontrolled registry data, needs to be carefully considered in the interpretation of the results.
Abstract Time to surgery after termination of neoadjuvant chemoradiotherapy for esophageal cancer has traditionally been 4–6 weeks. Observational studies have suggested that delay of surgery for up to three months may lead to improved tumor regression and better outcomes. NeoRes II is the first randomized trial to address this in esophageal cancer. No difference in surgical morbidity or mortality between early and delayed surgery was reported in a previous publication from the trial. A multicenter clinical trial with randomized 1:1 allocation of standard time to surgery of 4–6 weeks, or delay of surgery to 10–12 weeks, after termination of chemoradiotherapy. The primary endpoint was complete histological tumor regression in patients with adenocarcinoma. Secondary endpoints included tumor regression grade, tumor free resection margins and overall survival in all patients, and stratified by histological subtype. In total 249 patients were randomized, 204 with adenocarcinoma and 45 with squamous cell carcinoma. There was no significant difference in histological complete response between adenocarcinoma patients allocated to standard time to surgery (20.6%) compared to delayed (25.6%) surgery (P = 0.18). Tumor free resection margin was achieved in 97.4% after standard time to surgery and 97.1% after delayed surgery (P = 1.0). The median follow-up time for survival was 51 months. Delayed time to surgery was associated with a 35% higher overall mortality, hazard ratio 1.35 (95% CI:0.94–1.95), (P = 0.11). No significant difference in complete histological tumor regression or tumor free resection margins comparing standard and delayed time to surgery after chemoradiotherapy was observed. There was a non-significant trend towards inferior overall survival after delayed surgery, suggesting caution in delaying surgery for more than 6 weeks after neoadjuvant chemoradiotherapy.
6074 Background: Patients with HPV associated squamous cell carcinoma of the oropharynx have a favorable outcome with respect to tumor control and overall survival (OS) after treatment with chemoradiotherapy (CRT). The leading cause of death in these patients is reported to be peripheral metastases. Because of the favorable outcome for these patients, the medical community tries to find methods to ameliorate treatment intensity, mainly in order to reduce long term morbidity. However, between 10 and 15 % of patients relapse locally in the primary tumor as first site of disease failure. Methods: In this multicentre, randomized, controlled, phase II trial 152 patients with locoregionally advanced oropharyngeal cancer were randomized in a 1:1 ratio to either radiotherapy with cetuximab (arm B) versus the same regimen preceded by 2 cycles of induction chemotherapy (IC) with taxotere/cisplatin/5-FU (arm A). To decrease risk of local failure, an escalated radiation (RT) dose of 74.8 Gy was delivered to T3/T4 tumors and to T2 tumors > 3 cm in the base of tongue. Eligibility criteria included patients 18-75 years, ECOG performance status 0-1 and adequate organ functions. Primary endpoint of the study was to compare PFS between the treatment arms, secondary objectives were recurrence pattern, locoregional control, OS and toxicity. Results: PFS at 2 years was 84.2% (95%CI 76.4-92.8) in arm A and 78.4 (95%CI 69.5-88.3) in arm B (p = 0.20). At the time of analysis there were 26 disease failures, 9 in arm A and 17 in arm B. In arm A there were 3 local, 2 regional and 4 distant relapses as first site of recurrence, and in arm B 4, 4 and 9 relapses in corresponding sites. Local relapse rate as first site of failure was low, i.e. in 4.7%. Local failures constituted 7 relapses out of all 26 (27%), and in 4 of these local failures (57%), the escalated dose was given. In arm B, patients who had no IC, there were more than twice as many patients who had distant metastases as first site of relapse compared to arm A (n.s.). No patient who had a response to IC in the primary tumor or in regional lymph nodes, respectively, measured with CT or MRI, of either CR+CR or CR+PR, had any recurrence, local, regional or distant. So, IC could identify 22 out of 73 evaluable patients (30%) in arm A, who never had any recurrence during follow up. Conclusions: A high incidence of distant metastases as first site of failure is recognized while local failure rate is low. However, despite a high RT dose of 74.8 Gy, delivered to the primary tumor, relapses can appear in this site. Radiological response of tumor to IC could identify patients with no tumor relapse, at least within the first years of follow up, possible candidates for de-escalation treatment protocols. Clinical trial information: 2009-013438-26.
The globally dominant treatment with curative intent for locally advanced esophageal squamous cell carcinoma (ESCC) is neoadjuvant chemoradiotherapy (nCRT) with subsequent esophagectomy. This multimodal treatment leads to around 60% overall 5-year survival, yet with impaired post-surgical quality of life. Observational studies indicate that curatively intended chemoradiotherapy, so-called definitive chemoradiotherapy (dCRT) followed by surveillance of the primary tumor site and regional lymph node stations and surgery only when needed to ensure local tumor control, may lead to similar survival as nCRT with surgery, but with considerably less impairment of quality of life. This trial aims to demonstrate that dCRT, with selectively performed salvage esophagectomy only when needed to achieve locoregional tumor control, is non-inferior regarding overall survival, and superior regarding health-related quality of life (HRQOL), compared to nCRT followed by mandatory surgery, in patients with operable, locally advanced ESCC.This is a pragmatic open-label, randomized controlled phase III, multicenter trial with non-inferiority design with regard to the primary endpoint overall survival and a superiority hypothesis for the experimental intervention dCRT with regard to the main secondary endpoint global HRQOL one year after randomization. The control intervention is nCRT followed by preplanned surgery and the experimental intervention is dCRT followed by surveillance and salvage esophagectomy only when needed to secure local tumor control. A target sample size of 1200 randomized patients is planned in order to reach 462 events (deaths) during follow-up.www.ClinicalTrials.gov, identifier: NCT04460352.
ConclusionThe retrospective QA analysis of this prospective SBRT trial showed up to a 32% rate of dosimetric variations with potential impact on tumor control and/or toxicity profile.Use of an IMRT technique and inclusion of SV in the PTV were the major causes of protocol deviations.Integration of prospective RTQA protocols is encouraged for future PCa SBRT clinical trials to prevent and correct protocol violations before start of treatment.
