NTCP modelling of xerostomia after radiotherapy for oropharyngeal cancer using the PRO-CTCAE and CTCAE scoring systems at different time-points post-RT

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.

Tumor volume as a predictor of survival in advanced laryngeal cancer treated with total laryngectomy

BACKGROUND

Recent literature shows that tumor volume (TV) in T3 laryngeal squamous cell carcinoma (LSCC) is associated with response to radiation therapy. The aim of this study was to evaluate the effect of TV on survival outcomes in patients undergoing total laryngectomy (TL).

METHODS

One hundred and seventeen patients with LSCC undergoing TL between 2013 and 2020 at the University of Florida were included. TV was measured using a previously validated method on preoperative-CT scans. Multivariable CoxPH models for overall survival (OS) and disease-specific survival (DSS), metastasis-free survival (MFS), and recurrence-free survival (RFS) were developed with TV.

RESULTS

Mean age was 61.5 years and 81.2% were male. Higher TV was associated with decreased OS, MFS, DSS, and RFS with adjusted hazard ratios 1.02 (95%CI: 1.01, 1.03), 1.01, (95%CI: 1.00, 1.03), 1.03 (95%CI: 1.01, 1.06), and 1.02 (95%CI: 1.00, 1.03) respectively. TV >7.1 cc had worse prognoses.

CONCLUSIONS

TV appears associated with decreased survival in LSCC treated with TL.

Human Papillomavirus-Negative Oropharyngeal Cancer Survival Outcomes Based on Primary Treatment: National Cancer Database Analysis

OBJECTIVE

To compare survival outcomes between primary surgery and primary radiation therapy (RT) in patients with human papillomavirus (HPV)-negative oropharyngeal squamous cell carcinoma (OPSCC).

STUDY DESIGN

A retrospective observational cohort study.

SETTING

National Cancer Database.

METHODS

A National Cancer Database review was conducted of 2635 patients with HPV-negative OPSCC who underwent surgery or RT ± chemotherapy between 2010 and 2014. Univariate analysis was performed on all variables and entered into a multivariate model. The main outcome was overall survival (OS).

RESULTS

A total of 2635 patients with HPV-negative OPSCC were organized into 4 groups based on cancer staging. In group 1 (T1-2 N0-1; n = 774), up-front surgery had significantly better 5-year OS (76.2%) than RT (56.8%; adjusted hazard ratio [aHR], 1.76; P = .009; 95% CI, 1.15-2.69) and chemoradiation therapy (CRT; 69.5%; aHR, 1.56; P = .019; 95% CI, 1.08-2.26). In group 2 (T3-4 N0-1; n = 327), no significant difference existed between surgery and CRT (5-year OS, 51.3% vs 52.4%; aHR, 0.96; P = .88; 95% CI, 0.54-1.69). In group 3a (T1-2 N2-3; n = 807), surgery with adjuvant treatment showed significantly better 5-year OS than CRT (78.6% vs 68.8%; aHR, 1.51; P = .027; 95% CI, 1.05-2.18). In group 3b (T3-4 N2-3; n = 737), surgery with adjuvant treatment was not statistically associated with better 5-year OS as compared with CRT (61.0% vs 43.7%; aHR, 1.53; P = .06; 95% CI, 0.98-2.39).

CONCLUSION

Primary surgery may provide improved survival outcomes in many cases of HPV-negative OPSCCs. These data should be used in weighing treatment options and may serve as a basis to better delineate treatment algorithms for HPV-negative disease.

Woody hardness classification impact on salvage laryngectomy functional outcomes

PURPOSE

Post-radiation therapy salvage surgeries are challenging for surgeons due to tissue fibrosis. The woody hardness classification is valuable in differentiating the degree of neck stiffness, but its clinical utility has not been evaluated. We applied it to patients undergoing salvage laryngectomy to study the impact of woody hardness on postoperative outcomes.

MATERIALS AND METHODS

A retrospective observational study was performed on patients undergoing salvage laryngectomy between 2014 and 2019. Patients were assigned into the A (extremely woody hard), B (moderately woody hard), or C (mildly woody hard) woody hardness class. The primary outcome was pharyngoesophageal stricture development. Secondary outcomes included time to pharyngoesophageal stricture, pharyngocutaneous fistula development, time to pharyngocutaneous fistula, development of post-operative complications, and tracheoesophageal puncture complications.

RESULTS

Fifty-one patients were included in the study: Class A 1 patient, Class B 30 patients, and Class C 20 patients. The single Class A patient was grouped with the Class B patients. The development of a pharyngoesophageal stricture shows consistent negative association with woody hardness despite most analyses not reaching statistical significance. These associations are robust to a number of confounding variables in multivariate logistic and time to event analyses. Furthermore, the time to event analysis controlling for squamous cell carcinoma diagnosis led to a statistically significant association between woody hardness (i.e., A/B higher risk) and time to stricture (HR=5, p=0.02).

CONCLUSIONS

This study suggests that this classification may be useful in predicting pharyngoesophageal stricture formation in salvage laryngectomy patients and could be used to implement stricture preventive measures.

Metastatic Squamous Cell Carcinoma to the Cervical Lymph Nodes From an Unknown Primary Cancer: Management in the HPV Era

Background

Patients with metastases in the lymph nodes of the neck and no obvious primary tumor, neck cancer with unknown primary (NCUP), represent a management challenge. A majority of patients have metastatic squamous cell carcinoma (SCC), although other histologies do occur.

Methods

We comprehensively reviewed the literature, compared available guidelines, and conferred with an international team of experts.

Results

Positron emission tomography-computed tomography (PET-CT) and fine needle aspiration (FNA) under ultrasound guidance increase accuracy of diagnosis. Immunohistochemistry (IHC), determination of human papilloma virus (HPV) status, by p16 staining or by in situ hybridization (ISH), and next-generation gene sequencing can guide us regarding probable primary sites and tumor biology. Narrow Band Imaging (NBI) has been introduced for the early detection of subtle mucosal lesions. Direct laryngoscopy (DL) and tonsillectomy have long been procedures used in the search for a primary site. More recently, TransOral Robotic Surgery (TORS) or Transoral LASER Microsurgery (TLM) have been introduced for lingual tonsillectomy.

Conclusions

New technologies have been developed which can better detect, diagnose, and treat occult primary tumors. Decisions regarding therapy are based on the primary tumor site (if discovered) and N stage. Options include neck dissection with or without postoperative adjuvant therapy, primary irradiation, or combined chemotherapy with irradiation. The preferred treatment of patients whose primary remains unidentified is controversial.

Plasma Circulating Tumor HPV DNA for the Surveillance of Cancer Recurrence in HPV-Associated Oropharyngeal Cancer

PURPOSE

Plasma circulating tumor human papillomavirus DNA (ctHPVDNA) is a sensitive and specific biomarker of human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC). We investigated whether longitudinal monitoring of ctHPVDNA during post-treatment surveillance could accurately detect clinical disease recurrence.

METHODS AND MATERIALS

A prospective biomarker clinical trial was conducted among patients with nonmetastatic HPV-associated (p16-positive) OPSCC. All patients were treated with curative-intent chemoradiotherapy (CRT). Patients underwent a 3-month post-CRT positron emission tomography/computed tomography scan and were thereafter clinically evaluated every 2-4 months (years 1-2), then every 6 months (years 3-5). Chest imaging was performed every 6 months. Blood specimens were collected every 6-9 months for analysis of plasma ctHPVDNA using a multianalyte digital polymerase chain reaction assay. The primary endpoint was to estimate the negative predictive value (NPV) and positive predictive value (PPV) of ctHPVDNA surveillance.

RESULTS

One hundred fifteen patients were enrolled, and 1,006 blood samples were analyzed. After a median follow-up time of 23 months (range, 6.1-54.7 months), 15 patients (13%) developed disease recurrence. Eighty-seven patients had undetectable ctHPVDNA at all post-treatment time points, and none developed recurrence (NPV, 100%; 95% CI, 96% to 100%). Twenty-eight patients developed a positive ctHPVDNA during post-treatment surveillance, 15 of whom were diagnosed with biopsy-proven recurrence. Sixteen patients had 2 consecutively positive ctHPVDNA blood tests, 15 of whom developed biopsy-proven recurrence. Two consecutively positive ctHPVDNA blood tests had a PPV of 94% (95% CI, 70% to 99%). Median lead time between ctHPVDNA positivity and biopsy-proven recurrence was 3.9 months (range, 0.37-12.9 months).

CONCLUSION

Detection of ctHPVDNA in two consecutive plasma samples during post-treatment surveillance has high PPV and NPV for identifying disease recurrence in patients with HPV-associated oropharyngeal cancer and may facilitate earlier initiation of salvage therapy.

RARE-40. OUTCOMES AFTER PROTON THERAPY FOR SKULL-BASE CHORDOMA: A PROSPECTIVE STUDY

We evaluated treatment outcomes following definitive or adjuvant high-dose, image-guided proton therapy in 91 patients with skull-base chordoma enrolled on a prospective outcomes tracking protocol and treated between February 2007 and February 2018. The median age was 53 years (range, 22–78 years). Patients received passively scattered 3-dimensional conformal proton therapy to a median dose of 73.8 GyRBE (range, 69.6–75.6 GyRBE). Two patients received a component of intensity-modulated radiotherapy. Seventy percent (n=64) were men and 30% (n=27) were woman. Eighty-two percent (n=75) of patients had macroscopic disease at the time of radiotherapy; 18% (n=16) had undergone a macroscopic gross total resection. Overall survival, cause-specific survival, local control, and RT-related grade 3 toxicity-free survival were calculated. Proton therapy-related toxicities were scored using CTCAE v4.0. With a median follow-up of 3.7 years (range, 0.2–10 years), 26 patients experienced disease recurrence, including 26 local, 0 regional, and 1 distant recurrence. The median time to local progression was 2.2 years (range, 0.4–7.0 years). At the time of last follow-up, 66 patients were alive (56 with no evidence of disease progression) and 25 were deceased (18 with disease progression). There were no acute grade 3 toxicities related to the radiation therapy. The 4-year actuarial rates of overall survival, cause-specific survival, local control, and radiation therapy-related grade 3 toxicity-free survival were 83%, 87%, 76% and 83%, respectively. Definitive or adjuvant high-dose passively scattered 3-dimensional conformal proton therapy for skull-base chordoma provides acceptable local control, comparing favorably to historic photon data, with no acute grade ≥3 radiation-related toxicity and an acceptable rate of grade ≥3 late toxicity. Further follow-up of this cohort is necessary to better characterize long-term disease control and late toxicities.

Phase II Trial of De-Intensified Chemoradiotherapy for Human Papillomavirus-Associated Oropharyngeal Squamous Cell Carcinoma

PURPOSE

To report the results of a phase II clinical trial of de-intensified chemoradiotherapy for patients with human papillomavirus-associated oropharyngeal squamous cell carcinoma.

MATERIALS AND METHODS

Major inclusion criteria were (1) having American Joint Committee on Cancer (AJCC) 7th edition T0-T3, N0-N2c, M0 (AJCC 8th edition T0-T3, N0-N2, M0), (2) being p16 positive, and (3) reporting minimal or remote smoking history. Treatment was limited to 60 Gy intensity-modulated radiotherapy with concurrent intravenous cisplatin 30 mg/m2 once per week. Patients with T0-T2 N0-1 (AJCC 7th edition) did not receive chemotherapy. All patients had a 10- to 12-week post-treatment positron emission tomography/computed tomography to assess for neck dissection. The primary end point was 2-year progression-free survival. Secondary end points included 2-year local-regional control, distant metastasis-free survival and overall survival, and patient-reported outcomes (European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire and the patient-reported outcomes version of the Common Terminology Criteria for Adverse Events).

RESULTS

One hundred fourteen patients were enrolled (median follow-up of 31.8 months), with 81% having a minimum follow-up of 2 years. Eighty percent of patients had 10 or fewer tobacco pack-years. Two-year local-regional control, distant metastasis-free survival, progression-free survival, and overall survival were as follows: 95%, 91%, 86%, and 95%, respectively. Mean pre- and 2-year post-treatment European Organisation for Research and Treatment of Cancer quality of life scores were as follows: global, 79/84 (lower worse); swallowing, 8/9 (higher worse); and dry mouth, 14/45 (higher worse). Mean pre- and 2-year post-treatment patient-reported outcomes version of the Common Terminology Criteria for Adverse Events scores (0 to 4 scale, higher worse) were as follows: swallowing, 0.5/0.7, and dry mouth, 0.4/1.3. Thirty-four percent of patients required a feeding tube (median, 10.5 weeks; none permanent). There were no grade 3 or higher late adverse events.

CONCLUSION

Clinical outcomes with a de-intensified chemoradiotherapy regimen of 60 Gy intensity-modulated radiotherapy with concurrent low-dose cisplatin are favorable in patients with human papillomavirus-associated oropharyngeal squamous cell carcinoma. Neither neoadjuvant chemotherapy nor routine surgery is needed to obtain favorable results with de-escalation.

Rapid Clearance Profile of Plasma Circulating Tumor HPV Type 16 DNA during Chemoradiotherapy Correlates with Disease Control in HPV-Associated Oropharyngeal Cancer

PURPOSE

To identify a profile of circulating tumor human papilloma virus (HPV) DNA (ctHPVDNA) clearance kinetics that is associated with disease control after chemoradiotherapy (CRT) for HPV-associated oropharyngeal squamous cell carcinoma (OPSCC).

EXPERIMENTAL DESIGN

A multi-institutional prospective biomarker trial was conducted in 103 patients with (i) p16-positive OPSCC, (ii) M0 disease, and (iii) receipt of definitive CRT. Blood specimens were collected at baseline, weekly during CRT, and at follow-up visits. Optimized multianalyte digital PCR assays were used to quantify ctHPVDNA (types 16/18/31/33/35) in plasma. A control cohort of 55 healthy volunteers and 60 patients with non-HPV-associated malignancy was also analyzed.

RESULTS

Baseline plasma ctHPVDNA had high specificity (97%) and high sensitivity (89%) for detecting newly diagnosed HPV-associated OPSCC. Pretreatment ctHPV16DNA copy number correlated with disease burden, tumor HPV copy number, and HPV integration status. We define a ctHPV16DNA favorable clearance profile as having high baseline copy number (>200 copies/mL) and >95% clearance of ctHPV16DNA by day 28 of CRT. Nineteen of 67 evaluable patients had a ctHPV16DNA favorable clearance profile, and none had persistent or recurrent regional disease after CRT. In contrast, patients with adverse clinical risk factors (T4 or >10 pack years) and an unfavorable ctHPV16DNA clearance profile had a 35% actuarial rate of persistent or recurrent regional disease after CRT (P = 0.0049).

CONCLUSIONS

A rapid clearance profile of ctHPVDNA may predict likelihood of disease control in patients with HPV-associated OPSCC patients treated with definitive CRT and may be useful in selecting patients for deintensified therapy.

Detection of Distant Metastases in Head and Neck Cancer: Changing Landscape

As head and neck squamous cell carcinoma (HNSCC) patients with distant metastases (DM) were generally treated only palliatively, the value of screening for DM was usually limited to attempts to avoid extensive locoregional treatment when DM were present pretreatment. Recently, the concept of treating oligometastases, e.g., by metastatectomy or stereotactic body radiotherapy, has been reintroduced for HNSCC and may cause a change in the treatment paradigm. Although whole body ¹⁸F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) combined with computed tomography (CT; WB-FDG-PET/CT) is still the mainstay diagnostic technique, there is a growing body of evidence supporting implementation of whole body magnetic resonance imaging (WB-MRI) as an important diagnostic technique for screening for DM. Also, FDG-PET/MRI may become a valuable technique for the detection of DM in HNSCC patients. Because the yield of examinations for detection of DM is too low to warrant routine screening of all HNSCC patients, only patients with high risk factors should be selected for intense screening for DM. Clinical and histopathological risk factors are mainly related to the extent of lymph node metastases. Risk for development of DM may also be assessed by molecular characterization of the primary tumor using genomic and proteomic technologies and radiomics. More research is needed to develop a new protocol for screening for DM after introduction of the concept of treating oligometastases in HNSCC.

Dose-volume toxicity modeling for de-intensified chemo-radiation therapy for HPV-positive oropharynx cancer

BACKGROUND AND PURPOSE

The aim is to determine the radiobiological parameters of four popular normal tissue complication probability (NTCP) models that describe the dose-response relations of salivary glands and pharyngeal constrictors to the severity of patient reported xerostomia and dysphagia, respectively 6 and 12months post chemo-radiotherapy, furthermore, to evaluate the goodness-of-fit of the NTCP models for different combinations of glands and constrictors.

MATERIAL AND METHODS

Forty-three patients were treated on a prospective multi-institutional phase II study (ClinicalTrials.gov, NCT01530997) assessing the efficacy of de-intensified chemoradiotherapy in patients with favorable risk, HPV-associated oropharyngeal squamous cell carcinoma. All patients received 60Gy intensity modulated radiotherapy with concurrent weekly intravenous cisplatinum. All patients reported severity of their xerostomia and dysphagia (pre- and post-treatment) using the patient reported outcome version of the CTCAE (PRO-CTCAE). A change in severity (from baseline) of ≥2 was considered clinically meaningful. The Lyman-Kutcher-Burman (LKB), Relative Seriality (RS), Logit, and Relative Seriality Logit (RSL) NTCP models were used to fit the patients' dose/volume data to changes in PRO-CTCAE severity of xerostomia and dysphagia (from baseline to 6 and 12months post-treatment). The correlation of the models with the patient outcomes was performed for different combinations of salivary glands and different sections of pharyngeal constrictors. The goodness-of-fit of the different models was assessed through the area under the receiver operating characteristic curve (AUC), maximum of the log-likelihood function, normal error distribution and Akaike information criterion (AIC).

RESULTS

The dose/volume metrics of the combined contralateral (parotid+submandibular) glands appear to correlate best with xerostomia, at both 6- and 12-months. Among the different sections of pharyngeal constrictors, the dose/volume metrics of the superior pharyngeal constrictors appear to correlate best with dysphagia at 6months. The AUC values ranged from 0.72 to 0.85 in the case of xerostomia and 0.73 to 0.74 in the case of dysphagia over the different models. The four NTCP models showed similar goodness-of-fit. The differences in AIC between the different models were less than 2 and ranged within 0.7 and 0.8 in the cases of xerostomia and dysphagia, respectively. The calculated parameters of the LKB model were D₅₀=26.9Gy, m=0.63, n=1.0 for the combined contralateral glands at 12months and D₅₀=62.0Gy, m=0.10, n=0.49 for the superior pharyngeal constrictors at 6months.

CONCLUSIONS

The values of the parameters of four NTCP models were determined for salivary glands and pharyngeal constrictors. All four models could fit the clinical data equally well. The NTCP predictions of the combined contralateral glands and superior pharyngeal constrictors showed the best correlation with the patient reported outcomes of xerostomia and dysphagia, respectively.

Comparison of Patient- and Practitioner-Reported Toxic Effects Associated With Chemoradiotherapy for Head and Neck Cancer

IMPORTANCE

Agreement between patient- and practitioner-reported toxic effects during chemoradiotherapy for head and neck cancer is unknown.

OBJECTIVE

To compare patient-reported symptom severity and practitioner-reported toxic effects among patients receiving chemoradiotherapy for head and neck cancer.

DESIGN, SETTING, AND PARTICIPANTS

Forty-four patients participating in a phase 2 trial of deintensified chemoradiotherapy for oropharyngeal carcinoma were included in the present study (conducted from February 8, 2012, to March 2, 2015). Most treatment (radiotherapy, 60 Gy, with concurrent weekly administration of cisplatin, 30 mg/m2) was administered at academic medical centers. Included patients had no prior head and neck cancers, were 18 years or older, and had a smoking history of 10 pack-years or less or more than 10 pack-years but 30 pack-years or less and abstinent for the past 5 years. Cancer status was untreated human papillomavirus or p16-positive squamous cell carcinoma of the oropharynx or unknown head and neck primary site; and cancer staging was category T0 to T3, category N0 to N2c, M0, and Eastern Cooperative Oncology Group performance status 0 to 1. Baseline, weekly, and posttreatment toxic effects were assessed by physicians or nurse practitioners using National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE), version 4.0. Patient-reported symptom severity was measured using the Patient-Reported Outcomes version of the CTCAE (PRO-CTCAE). Descriptive statistics were used to characterize raw agreement between CTCAE grades and PRO-CTCAE severity ratings.

INTERVENTIONS

Baseline, weekly, and posttreatment toxic effects assessed using CTCAE, version 4.0, and PRO-CTCAE.

MAIN OUTCOMES AND MEASURES

Raw agreement indices between patient-reported toxic effects, including symptom frequency, severity, and interference with daily activities (score range, 0 [none] to 4 [very severe]), and practitioner-measured toxic effects, including swallowing, oral pain, and hoarseness (score range, 1 [mild] to 5 [death]).

RESULTS

Of the 44 patients included in the analysis (39 men, 5 women; mean [SD] age, 61 [8.4] years), there were 327 analyzable pairs of CTCAE and PRO-CTCAE symptom surveys and no treatment delays due to toxic effects. Patient-reported and practitioner-reported symptom severity agreement was high at baseline when most symptoms were absent but declined throughout treatment as toxic effects increased. Most disagreement was due to lower severity of toxic effects reported by practitioners (eg, from 45% agreement at baseline to 27% at the final week of treatment for pain). This was particularly noted for domains that are not easily evaluated by physical examination, such as anxiety and fatigue (eg, severity of fatigue decreased from 43% at baseline to 12% in the final week of treatment).

CONCLUSIONS AND RELEVANCE

Practitioner-reported toxic effects are lower than patient self-reports during head and neck chemoradiotherapy. The inclusion of patient-reported symptomatic toxic effects provides information that can potentially enhance clinical management and improve data quality in clinical trials.

Dosimetric Predictors of Patient-Reported Xerostomia and Dysphagia With Deintensified Chemoradiation Therapy for HPV-Associated Oropharyngeal Squamous Cell Carcinoma

PURPOSE/OBJECTIVE(S)

To estimate the association between different dose-volume metrics of the salivary glands and pharyngeal constrictors with patient reported severity of xerostomia/dysphagia in the setting of deintensified chemoradiation therapy (CRT).

METHODS AND MATERIALS

Forty-five patients were treated on a phase 2 study assessing the efficacy of deintensified CRT for favorable-risk, HPV-associated oropharyngeal squamous cell carcinoma. Patients received 60 Gy intensity modulated radiation therapy with concurrent weekly cisplatin (30 mg/m²), and reported the severity of their xerostomia/dysphagia (before and after treatment) using the patient-reported outcome version of the Common Terminology Criteria for Adverse Events (CTCAE) (PRO-CTCAE). Individual patient dosimetric data of the contralateral parotid and submandibular glands and pharyngeal constrictors were correlated with changes in PRO-CTCAE severity. A change in severity (from baseline) of ≥2 was considered clinically meaningful. Associations between dose-volume metrics and patient outcomes were assessed with receiver operating characteristic (ROC) curve and logistic regression model.

RESULTS

Six months after CRT, patients reporting <2 change in xerostomia severity (n=14) had an average D_mean = 22 ± 9 Gy to the sum of the contralateral glands (parotid + submandibular) compared with the patients reporting ≥2 change (n=21), who had an average D_mean = 34 ± 8 Gy. V15 to V55 for the combined contralateral glands showed the strongest association with xerostomia (area under the curve [AUC] = 0.83-0.86). Based on the regression analysis, a 20% risk of toxicity was associated with V15 = 48%, V25 = 30%, and D_mean=21 Gy. Six months after CRT, patients reporting <2 change in dysphagia severity (n=26) had an average V55 = 76 ± 13 (%) to the superior pharyngeal constrictor compared with the patients reporting ≥2 change in severity (n=9), who had average V55 = 89 ± 13 (%). V55to V60 had the strongest association with dysphagia (AUC = 0.70-0.75). Based on the regression analysis, a 20% risk of toxicity was associated with V55 = 78%, V60 = 40%. The findings at 12 months were similar.

CONCLUSIONS

After deintensified CRT, the rate of patient-reported xerostomia/dysphagia appears to be associated with the V15 of the combined contralateral salivary glands and V55 to V60 of the superior pharyngeal constrictors.

Phase 2 Trial of De-intensified Chemoradiation Therapy for Favorable-Risk Human Papillomavirus-Associated Oropharyngeal Squamous Cell Carcinoma

PURPOSE

To perform a prospective, multi-institutional, phase 2 study of a substantial decrease in concurrent chemoradiation therapy (CRT) intensity as primary treatment for favorable-risk, human papillomavirus-associated oropharyngeal squamous cell carcinoma.

METHODS AND MATERIALS

The major inclusion criteria were: (1) T0 to T3, N0 to N2c, M0; (2) human papillomavirus or p16 positive; and (3) minimal/remote smoking history. Treatment was limited to 60 Gy intensity modulated radiation therapy with concurrent weekly intravenous cisplatinum (30 mg/m(2)). The primary study endpoint was pathologic complete response (pCR) rate based on required biopsy of the primary site and dissection of pretreatment positive lymph node regions, regardless of radiographic response. Power computations were performed for the null hypothesis that the pCR rate is 87% and n=40, resulting in a type 1 error of 14.2%. Secondary endpoint measures included physician-reported toxicity (Common Toxicity Terminology for Adverse Events, CTCAE), patient-reported symptoms (PRO-CTCAE), and modified barium swallow studies.

RESULTS

The study population was 43 patients. The pCR rate was 86% (37 of 43). The incidence of CTCAE grade 3/4 toxicity and PRO-CTCAE severe/very severe symptoms was as follows: mucositis 34%/45%, general pain 5%/48%, nausea 18%/52%, vomiting 5%/34%, dysphagia 39%/55%, and xerostomia 2%/75%. Grade 3/4 hematologic toxicities were 11%. Thirty-nine percent of patients required a feeding tube for a median of 15 weeks (range, 5-22 weeks). There were no significant differences in modified barium swallow studies before and after CRT.

CONCLUSIONS

The pCR rate with decreased intensity of therapy with 60 Gy of IMRT and weekly low-dose cisplatinum is very high in favorable-risk oropharyngeal squamous cell carcinoma, with evidence of decreased toxicity compared with standard therapies. ClinicalTrials.gov ID: NCT01530997.

Vestibular Apparatus Dysfunction after External Beam Radiation Therapy for Head and Neck Cancers

Objectives:

Radiation therapy (RT) for head and neck cancers (HNC) may be associated with vestibular dysfunction (VD). The goal of this study is to examine the post-RT incidence of VD in HNC patients receiving RT +/- chemotherapy (chemo) and its association with patient and treatment related factors.

Methods:

Pre and post-RT records of 376 HNC patients were retrospectively assessed for the presence of possible VD. Dose received by vestibular apparatus was estimated using the CT-based treatment plan for the patient. Uni- and multivariate analyses evaluated the association between various variables and incidence of VD.

Results:

Subjective vertigo or dizziness was reported in 53(14.5%) patients over a median time of 16 months (range 0 to 36 months). Abnormal elecronystagmography was observed in 41 of 49 (83.6%) tested patients: 24 (48.9%) bithermal caloric stimulation, 8 (16.3%) sinusoidal tracking, and 5 (10.2%) with both. Doses received by vestibular apparatus varied between 45 to 80 Gy. Vestibular RT dose was significantly associated with VD ( P < 0.05), but age (>60), gender, fractionation were not. Use of chemo was marginally associated with VD ( P = 0.056).

Conclusions:

Radiation dose to the vestibular apparatus appears to be the primary determinant of VD in HNC patients treated with RT. Further prospective investigation is needed to better understand the effects of RT and chemo-RT on vestibular apparatus.

Hypofractionated passively scattered proton radiotherapy for low- and intermediate-risk prostate cancer is not associated with post-treatment testosterone suppression

Background.

To investigate post-treatment changes in serum testosterone in low- and intermediate-risk prostate cancer patients treated with hypofractionated passively scattered proton radiotherapy.

Material and methods.

Between April 2008 and October 2011, 228 patients with low- and intermediate-risk prostate cancer were enrolled into an institutional review board-approved prospective protocol. Patients received doses ranging from 70 Cobalt Gray Equivalent (CGE) to 72.5 CGE at 2.5 CGE per fraction using passively scattered protons. Three patients were excluded for receiving androgen deprivation therapy (n = 2) or testosterone supplementation (n = 1) before radiation. Of the remaining 226 patients, pretreatment serum testosterone levels were available for 217. Of these patients, post-treatment serum testosterone levels were available for 207 in the final week of treatment, 165 at the six-month follow-up, and 116 at the 12-month follow-up. The post-treatment testosterone levels were compared with the pretreatment levels using Wilcoxon's signed-rank test for matched pairs.

Results.

The median pretreatment serum testosterone level was 367.7 ng/dl (12.8 nmol/l). The median changes in post-treatment testosterone value were as follows: +3.0 ng/dl (+0.1 nmol/l) at treatment completion; +6.0 ng/dl (+0.2 nmol/l) at six months after treatment; and +5.0 ng/dl (0.2 nmol/l) at 12 months after treatment. None of these changes were statistically significant.

Conclusion.

Patients with low- and intermediate-risk prostate cancer treated with hypofractionated passively scattered proton radiotherapy do not experience testosterone suppression. Our findings are consistent with physical measurements demonstrating that proton radiotherapy is associated with less scatter radiation exposure to tissues beyond the beam paths compared with intensity-modulated photon radiotherapy.

Phase II study of palifermin and concurrent chemoradiation in head and neck squamous cell carcinoma

PURPOSE

Acute mucositis is a dose-limiting toxicity of concurrent chemoradiotherapy regimens for locally advanced head and neck cancer. Palifermin (a recombinant human keratinocyte growth factor; DeltaN23-KGF) stimulates the proliferation and differentiation of mucosal epithelium to reduce mucositis in patients receiving intensive therapy for hematologic cancers. This study assessed the efficacy and safety of palifermin in patients receiving concurrent chemoradiotherapy for advanced head and neck squamous cell carcinoma.

PATIENTS AND METHODS

In a phase II trial, standard radiotherapy was delivered in daily 2-Gy fractions to 70 Gy, or hyperfractionated radiotherapy was delivered in 1.25-Gy fractions twice daily to 72 Gy, over 7 weeks. Chemotherapy included cisplatin 20 mg/m(2) for 4 days and continuous-infusion fluorouracil 1,000 mg/m(2)/d for 4 days on weeks 1 and 5 of irradiation. Patients were randomly assigned 2:1 to palifermin 60 microg/kg or placebo once weekly for 10 doses. A follow-up trial evaluated long-term survival.

RESULTS

Sixty-seven patients received palifermin and 32 received placebo. The median duration of grade >or= 2 mucositis was 6.5 and 8.1 weeks in the palifermin and placebo groups, respectively (P = .157). Palifermin appeared to reduce mucositis, dysphagia, and xerostomia during hyperfractionated radiotherapy (n = 40) but not standard radiation therapy (n = 59). Adverse events were similar between treatment groups. Palifermin did not alter tumor response or survival.

CONCLUSION

Ten once-weekly doses of palifermin at 60 microg/kg were well tolerated. Most patients completed treatment, but palifermin did not reduce the morbidity of concurrent chemotherapy and radiotherapy. Future studies should evaluate higher palifermin doses with longer and more standardized assessment of acute mucositis.

Matching Intensity-Modulated Radiation Therapy to an Anterior Low Neck Field

When using intensity-modulated radiation therapy (IMRT) to treat head and neck cancer with the primary site above the level of the larynx, there are two basic options for the low neck lymphatics: to treat the entire neck with IMRT, or to match the IMRT plan to a conventional anterior "low neck" field. In view of the potential advantages of using a conventional low neck field, it is important to look for ways to minimize or manage the problems of matching IMRT to a conventional radiotherapy field. Treating the low neck with a single anterior field and the standard larynx block decreases the dose to the larynx and often results in a superior IMRT plan at the primary site. The purpose of this article is to review the most applicable studies and to discuss our experience with implementing a technique that involves moving the position of the superior border of the low neck field several times during a single treatment fraction.

Phase I study of 5-fluorouracil and leucovorin by continuous infusion chronotherapy and pelvic radiotherapy in patients with locally advanced or recurrent rectal cancer

PURPOSE

To determine the maximal tolerated dose of chronomodulated 5-fluorouracil (5-FU) and leucovorin (LV) given concurrently with radiotherapy in patients with rectal cancer.

METHODS AND MATERIALS

Forty-five patients with T3, T4 or recurrent rectal cancer received concurrent radiotherapy to a minimal dose of 4500 cGy. Chemotherapy was administered by a programmable pump in chronomodulated fashion, with 62.5% of the total dose given within 7 hours around 9:30 pm. The starting doses were LV at 5 mg/m2/d and 5-FU at 150 mg/m2/d. LV was escalated in 5-mg/m2 increments to 20 mg/m2/d; 5-FU was then escalated in 25 mg/m2 increments to the maximal tolerated dose.

RESULTS

Diarrhea and stomatitis were dose limiting, with Grade 3 or worse toxicity occurring in 16% and 5% of patients, respectively. Thirty-seven patients (84%) received their scheduled dose of radiotherapy (range, 4500-6000 cGy). Thirty-two patients had clinical T3 disease; all were treated with definitive surgery; 23 (71%) underwent sphincter-sparing surgery with complete resection in 28 (87%). Ten patients (31%) had no evidence of tumor in the pathologic specimen.

CONCLUSION

Preoperative chemoradiotherapy in rectal cancer using chronomodulated 5-FU and LV is feasible. The recommended Phase II dose is 5-FU 200 mg/m2 and LV 20 mg/m2 daily for 5 weeks.

Preradiotherapy computed tomography as a predictor of local control in supraglottic carcinoma

PURPOSE

To determine the utility of pretreatment computed tomography (CT) for predicting primary site control in patients with supraglottic squamous cell carcinoma (SCC) treated with definitive radiotherapy (RT).

MATERIALS AND METHODS

Pretreatment CT studies in 63 patients were reviewed. Minimum length of follow-up was 2 years. Local recurrence and treatment complications resulting in permanent loss of laryngeal function were documented. Tumor volume was calculated using a computer digitizer, and pre-epiglottic space (PES) spread was estimated. The data were analyzed using a combination of Fisher's exact test, logistic regression modeling, and multivariate analyses. Five-year local control rates were calculated using the product-limit method.

RESULTS

Local control rates were inversely and roughly linearly related to tumor volume, although there seemed to be a threshold volume at which primary site prognosis diminished. Local control was 89% in tumors less than 6 cm3 and 52% when volumes were > or =6 cm3 (P = .0012). The likelihood of maintaining laryngeal function also varied with tumor volume: 89% for tumors less than 6 cm3 and 40% for tumors > or =6 cm3 (P = .00004). Pre-epiglottic space involvement by tumor of > or =25% was associated with a reduced chance of saving the larynx (P = .0076). Multivariate analyses revealed that only tumor volume independently altered these end points.

CONCLUSION

Pretreatment CT measurements of tumor volume permits stratification of patients with supraglottic SCC treated with RT alone (which allows preservation of laryngeal function) into groups in which local control is more likely and less likely. Pre-epiglottic space spread is not a contraindication to using RT as the primary treatment for supraglottic SCC.