Should Stereotactic Radiosurgery Be Considered for Salvage of Intracranial Recurrence after Prophylactic Cranial Irradiation or Whole Brain Radiotherapy in Small Cell Lung Cancer? A Population-Based Analysis and Literature Review.

BACKGROUND: Prophylactic cranial irradiation (PCI) improves survival and prevents intracranial recurrence (IR) in limited stage (LS) and extensive stage (ES) small cell lung cancer (SCLC). However, despite PCI, IR affects 12%-45%, and limited data exist regarding salvage brain reirradiation (ReRT). We performed a population-based review of IR in SCLC. METHODS: Demographic, treatment, and outcome data of consecutive patients (N = 371) with SCLC assessed at a tertiary cancer centre (01/2013-12/2015) were abstracted, and summary statistics calculated. Kaplan-Meier estimates and univariate and multivariate analysis (MVA) via the Cox proportional hazard model were performed. RESULTS: Median age was 66.1 years, and 59.8% were Eastern Cooperative Oncology Group (ECOG) performance status 0-2. Median survival was 24 months (95% CI 18.3-29.7 months) for LS (N = 103) and 7 months (95% CI 6.1-7.9 months) for ES (N = 268). 72 of 103 patients with LS and 97 of 214 of those with ES received PCI. 54 of 268 ES presented with brain metastases (BM) of whom 46 of 54 received whole brain RT (WBRT). 18.9% (32/169) recurred post-PCI (13 LS; 19 ES) and 30.4% (14/46) recurred after WBRT. Of those who recurred/progressed after cranial RT, 56.5% (26/46) had <5 BM, 39.1% had no extracranial disease, and 50% were ECOG 0-2. In retrospect, 17 of 46 would have been candidates for salvage stereotactic radiosurgery: 13 post-PCI and 4 post-WBRT. CONCLUSIONS: This cohort challenges commonly held beliefs that IR is always diffuse, associated with clinical deterioration, and synchronous with systemic failure. Approximately 1 in 3 SCLC patients with IR after PCI or WBRT appear clinically appropriate for salvage stereotactic radiosurgery.

Evolution of the Radiation Therapist Role in a Multidisciplinary Palliative Radiation Oncology Clinic.

BACKGROUND: Palliative radiation therapists (PRTs) have been integrated in varying capacities into outpatient palliative radiation therapy (RT) services across Canada for over 2 decades. At our institution, PRTs have developed an essential role over 11 years within a palliative radiation oncology (PRO) clinic that focuses on integrating symptom management with radiation oncology assessment for palliative RT. PRTs have had direct clinical, technical, research, and administrative involvement as the clinic evolved from a pilot in 2007 supporting one half-day per week to the current model of five full clinical days. METHODS: Using collaborative reflection, we explored the PRTs' experience and insight. Twelve PRTs who contributed to the PRO clinic for varying lengths of time from 2007 through to 2016 were invited to participate in the development of a collective expression of the PRT experience. Seven PRTs consented to completing an electronic survey consisting of fifteen open-ended questions regarding individual roles and perspectives relating to our PRO clinic. Survey answers were enhanced by semistructured interviews when needed for clarification. Responses were contextualized within the operational changes to our multidisciplinary clinical model, from pilot to integrated service. RESULTS/DISCUSSION: Five respondents answered all of the questions. From the narratives, PRT roles and responsibilities were outlined and their insights and reflections included to contextualize clinical changes. Four phases of the clinic were identified and elucidated. Beginning in January 2007, three PRTs staffed a multidisciplinary clinical pilot one half-day per week for single-fraction, symptomatic bone metastases. The clinic has now evolved through various iterations to the current model with four PRTs sharing a "navigator" role with two registered nurses five full clinic days per week. The range of PRT experiences, responsibilities, and challenges encountered reflected specific clinical and operational conditions. CONCLUSION: As our clinical service model evolved from short-term pilot to fully integrated departmental service, so did the PRT role. PRTs contributing to RT as part of a multidisciplinary model support and advance nontraditional involvement in the holistic care of patients with advanced cancer.

Low-Activity Radioactive Iodine Therapy for Thyroid Carcinomas Exhibiting Nodal Metastases and Extrathyroidal Extension May Lead to Early Disease Recurrence.

BACKGROUND: The application of radioactive iodine in differentiated thyroid carcinomas has become more selective in an attempt to decrease morbidity. While ablative success has been documented, it is less clear how changes in radioactive iodine treatment strategies will influence long-term recurrence rates for patients with larger tumors and adverse pathological features, including extrathyroidal extension and nodal metastases. METHODS: Patients diagnosed between 1995 and 2008 with differentiated thyroid carcinoma treated with thyroidectomy followed by radioactive iodine treatment were eligible. All patients were followed for a minimum of five years using a standardized follow-up protocol requiring both biochemical and imaging assessments for recurrent disease (n = 219). Patients were stratified by initial radioactive iodine activity, and disease-free survival was calculated using the Kaplan-Meier method, with significant differences defined by the log-rank test. RESULTS: In this cohort, 46% of patients had clinical metastases and 74% had primary tumors >1.5 cm. Patients who had recurrences were more likely to present with extrathyroidal extension (p = 0.002) and lymph node metastases at diagnosis (p < 0.001). Patients presenting with both extrathyroidal extension and lymph node metastases had a significantly worse time to progression if treated with <1850 MBq radioactive iodine compared to those patients treated with >1850 MBq (25 months vs. 121 months; p = 0.004). The use of lower-activity radioactive iodine ablative therapy was associated with more early recurrences (p = 0.003). Being aged younger or older than 45 years did not impact the time to recurrence nor did the use of level 6 dissection. On multivariate analysis, lymph node metastases at diagnosis and multiple applications of radioactive iodine were linked to increased risk of recurrence. Patients with neither, or only one, adverse pathologic feature had excellent outcomes, regardless of initial ablative activity, with <10% of patients recurring over a 10-year time span. CONCLUSIONS: Recurrent disease in differentiated thyroid carcinoma is more common in patients treated with low-activity radioactive iodine in patients with lymph node metastases and extrathyroidal extension. These recurrences typically occur within four years of initial treatment. Patients lacking both of these risk factors treated with low radioactive iodine activity (<1850 MBq) have excellent outcomes, even after 10 years.

Human papillomavirus in oropharyngeal cancer in Canada: analysis of 5 comprehensive cancer centres using multiple imputation.

BACKGROUND: The incidence of oropharyngeal cancer has risen over the past 2 decades. This rise has been attributed to human papillomavirus (HPV), but information on temporal trends in incidence of HPV-associated cancers across Canada is limited. METHODS: We collected social, clinical and demographic characteristics and p16 protein status (p16-positive or p16-negative, using this immunohistochemistry variable as a surrogate marker of HPV status) for 3643 patients with oropharyngeal cancer diagnosed between 2000 and 2012 at comprehensive cancer centres in British Columbia (6 centres), Edmonton, Calgary, Toronto and Halifax. We used receiver operating characteristic curves and multiple imputation to estimate the p16 status for missing values. We chose a best-imputation probability cut point on the basis of accuracy in samples with known p16 status and through an independent relation between p16 status and overall survival. We used logistic and Cox proportional hazard regression. RESULTS: We found no temporal changes in p16-positive status initially, but there was significant selection bias, with p16 testing significantly more likely to be performed in males, lifetime never-smokers, patients with tonsillar or base-of-tongue tumours and those with nodal involvement (p < 0.05 for each variable). We used the following variables associated with p16-positive status for multiple imputation: male sex, tonsillar or base-of-tongue tumours, smaller tumours, nodal involvement, less smoking and lower alcohol consumption (p < 0.05 for each variable). Using sensitivity analyses, we showed that different imputation probability cut points for p16-positive status each identified a rise from 2000 to 2012, with the best-probability cut point identifying an increase from 47.3% in 2000 to 73.7% in 2012 (p < 0.001). INTERPRETATION: Across multiple centres in Canada, there was a steady rise in the proportion of oropharyngeal cancers attributable to HPV from 2000 to 2012.

Dose-escalated Hypofractionated Intensity-modulated Radiation Therapy With Concurrent Chemotherapy for Inoperable or Unresectable Non-Small Cell Lung Cancer.

PURPOSE: The local control of inoperable non-small cell lung cancer (NSCLC) using standard radiotherapy (RT) doses is inadequate. Dose escalation is a potential strategy to improve the local control for patients with NSCLC; however, the optimal dose required for local control in this setting is unknown. METHODS AND MATERIALS: Patients with unresectable or inoperable stage II/III NSCLC with ECOG≤1 received 48 Gy in 20 daily fractions using intensity-modulated radiotherapy, followed by 1 of 3 boost dose levels: 16.8 Gy/7 (cumulative 2 Gy equivalent dose [EQD2]≅76 Gy/38), 20.0 Gy/7 (EQD2≅84 Gy/42), and 22.7 Gy/7 (EQD2≅92 Gy/46). Two cycles of cisplatin/etoposide chemotherapy were given concurrent with RT. The maximum tolerated dose was defined as the dose at which ≥30% experienced dose-limiting toxicity (any NCIC Common Terminology for Adverse Events V3.0 grade 3 or higher acute toxicity). RESULTS: Twelve patients completed treatment with a median follow-up of 22 months (range, 7 to 48). The median age was 72 (range, 54 to 80) and 50% of patients had adenocarcinoma. Five, 3, and 4 patients were treated on dose levels 1, 2, and 3, respectively. No dose-limiting toxicity was observed. One-year local progression-free survival and overall survival estimates were 81% and 58%, respectively. CONCLUSIONS: Hypofractionated intensity-modulated radiotherapy was well tolerated and provided meaningful local control for patients with locally advanced inoperable NSCLC. The maximum tolerated dose of RT in this setting lies beyond an EQD2 of 92 Gy/46 and further dose escalation in this setting is warranted.

Supporting Patients With Incurable Cancer: Backup Behavior in Multidisciplinary Cross-Functional Teams.

Caring for patients with incurable cancer presents unique challenges. Managing symptoms that evolve with changing clinical status and, at the same time, ensuring alignment with patient goals demands specific attention from clinicians. With care needs that often transcend traditional service provision boundaries, patients who seek palliation commonly interface with a team of providers that represents multiple disciplines across multiple settings. In this case study, we explore some of the dynamics of a cross-disciplinary approach to symptom management in an integrated outpatient radiotherapy service model. Providers who care for patients with incurable cancer must rely on one another to secure delivery of the right services at the right time by the right person. In a model of shared responsibilities, flexibility in who does what and when can enhance overall team performance. Adapting requires within-team and between-team monitoring of task and function execution for any given patient. This can be facilitated by a common understanding of the purpose of the clinical team and an awareness of the particular circumstances surrounding care provision. Backup behavior, in which one team member steps in to help another meet an expectation that would otherwise not be fulfilled, is a supportive team practice that may follow naturally in high-functioning teams. Such team processes as these have a place in the care of patients with incurable cancer and help to ensure that individual provider efforts more effectively translate into improved palliation for patients with unmet needs.

The changing incidence of human papillomavirus-associated oropharyngeal cancer using multiple imputation from 2000 to 2010 at a Comprehensive Cancer Centre.

INTRODUCTION: Human papillomavirus (HPV) is a risk and prognostic factor for oropharyngeal cancer (OPC). Determining whether the incidence of HPV-associated OPC is rising informs health policy. METHODS: HPV status was ascribed using p16 immunohistochemistry in 683/1474 OPC patients identified from the Princess Margaret Hospital's Cancer Registry (from 2000 to 2010). Missing p16 data was estimated using multiple (n=100) imputation (MI) and validated using an independent OPC cohort (n=214). Non-OPC head and neck squamous cell carcinoma (HNSCC) (n=3262) were also used for time-trend comparison. Regression was used to compare HNSCC subsets and time-trends. The c-index was used to measure the predictive ability of MI. RESULTS: The incidence of OPC rose from 23.3% of all HNSCC in 2000 to 31.2% in 2010 (p=0.002). In the subset of OPC tested for p16, there was no change in p16 positivity over time (p=0.9). However, p16 testing became more frequent over time (p<0.0001), but was nonetheless biased, favouring never-smokers [OR 1.87 (95% CI 1.29-2.70)] and tumors of the tonsil [OR 2.30 (1.52-3.47)] or base-of-tongue [OR 1.72 (1.10-2.70)]. These same factors were also associated with p16-positivity [ORs 3.22 (1.27-8.16), 7.26 (3.50-15.1), 5.83 (2.70-12.7), respectively]. Following MI and normalization, the proportion of OPC that was p16-associated rose from 39.8% in 2000 to 65.0% in 2010, p=0.002, fully explaining the rise in OPC in our patient population. CONCLUSION: The rise in HNSCC referrals seen from 2000 to 2010 at our institution was driven primarily by p16-associated OPC. MI was necessary to derive reliable conclusions when cases with missing data are considerable.

Validation of a one-page patient-reported Charlson comorbidity index questionnaire for upper aerodigestive tract cancer patients.

OBJECTIVES: Cancer patients have a wide range of comorbidities that are important confounders for biomarker and clinical studies of prognosis and outcome. Comorbidities can be captured using the Charlson Comorbidity Index (CCI) through abstraction of medical records, but patient-reported outcome (PRO) questionnaires have also been used. The objective was to validate the PRO-CCI in a head and neck cancer (HNC) population, and to assess its level of agreement with the standard (std-CCI) method of chart review. METHODS: A one-page PRO-CCI was compared with the std-CCI obtained through independent abstraction in 882 HNC patients (2007-2010). Kappa statistics and associated measures (p(pos) and p(neg)) were used to assess agreement. Discrepancy for each comorbid illness was evaluated. Proportional hazard models compared the association of std-CCI and PRO-CCI with overall survival (OS). Adjustments were made and a modified PRO-CCI was re-evaluated in a new cohort of upper aerodigestive tract cancers patient. RESULTS: PRO-CCI was higher than the std-CCI (p < 0.0001). After adjustment, having at least two comorbidities according to either the std-CCI [HR 1.97 (1.38-2.80)] or the PRO-CCI [HR 1.62 (1.18-2.24)] was prognostic. Of the most prevalent comorbidities, agreement was high for most of the CCI elements (kappa 0.76-0.93), but poorest agreement for connective tissue disease (kappa = 0.29, p(pos) = 43%, p(neg) = 84%) and COPD (kappa = 0.48, p(pos) = 53%, p(neg) = 95%). When the connective tissue disease question was modified, agreement of this item improved (kappa = 0.47, p(pos) = 50%). CONCLUSION: PRO-CCI can be an easy and effective tool in prognostic and outcomes research in HNC patients.

Stereotactic radiosurgery for retreatment of gross perineural invasion in recurrent cutaneous squamous cell carcinoma of the head and neck.

OBJECTIVES: To report outcomes, failure patterns, and toxicity after stereotactic radiosurgery (SRS) for recurrent head and neck cutaneous squamous cell carcinoma with gross perineural invasion (GPNI). METHODS: Ten patients who received SRS as part of retreatment for recurrent head and neck cutaneous squamous cell carcinoma with GPNI were included. All patients exhibited clinical and radiologic evidence of GPNI before SRS. Previous treatments included surgery alone in 3 patients and surgery with adjuvant external beam radiotherapy (EBRT) in 7 patients. Retreatment included SRS alone in 2 and EBRT boosted with SRS in 8 patients. Magnetic resonance images were obtained every 3 to 6 months after SRS to track failure patterns. RESULTS: At a median 22-month follow-up, the 2-year progression-free and overall survival rates were 20% and 50%, respectively. Seven patients exhibited local failures, all of which occurred outside both SRS and EBRT fields. Five local failures occurred in previously clinically uninvolved cranial nerves (CNs). CN disease spreads through 3 distinct patterns: among different branches of CN V; between CNs V and VII; and between V1 and CNs III, IV, and/or VI. Five patients experienced side effects potentially attributable to radiation. CONCLUSIONS: Although there is excellent in-field control with this approach, the rate of out-of-field failures remains unacceptably high. We found that the majority of failures occurred in previously clinically uninvolved CNs often just outside treatment fields. Novel treatment strategies targeting this mode of perineural spread are needed.

Prognostic value of metabolic tumor volume and velocity in predicting head-and-neck cancer outcomes.

PURPOSE: We previously showed that metabolic tumor volume (MTV) on positron emission tomography-computed tomography (PET-CT) predicts for disease recurrence and death in head-and-neck cancer (HNC). We hypothesized that increases in MTV over time would correlate with tumor growth and biology, and would predict outcome. We sought to examine tumor growth over time in serial pretreatment PET-CT scans. METHODS AND MATERIALS: From 2006 to 2009, 51 patients had two PET-CT scans before receiving HNC treatment. MTV was defined as the tumor volume ≥ 50% of maximum SUV (SUV(max)). MTV was calculated for the primary tumor, nodal disease, and composite (primary tumor + nodes). MTV and SUV velocity were defined as the change in MTV or SUV(max) over time, respectively. Cox regression analyses were used to examine correlations between SUV, MTV velocity, and outcome (disease progression and overall survival). RESULTS: The median follow-up time was 17.5 months. The median time between PET-CT scans was 3 weeks. Unexpectedly, 51% of cases demonstrated a decrease in SUV(max) (average, -0.1 cc/week) and MTV (average, -0.3 cc/week) over time. Despite the variability in MTV, primary tumor MTV velocity predicted disease progression (hazard ratio 2.94; p = 0.01) and overall survival (hazard ratio 1.85; p = 0.03). CONCLUSIONS: Primary tumor MTV velocity appears to be a better prognostic indicator of disease progression and survival in comparison to nodal MTV velocity. However, substantial variability was found in PET-CT biomarkers between serial scans. Caution should be used when PET-CT biomarkers are integrated into clinical protocols for HNC.

On-board imaging validation of optically guided stereotactic radiosurgery positioning system for conventionally fractionated radiotherapy for paranasal sinus and skull base cancer.

PURPOSE: To evaluate the positioning accuracy of an optical positioning system for stereotactic radiosurgery in a pilot experience of optically guided, conventionally fractionated, radiotherapy for paranasal sinus and skull base tumors. METHODS AND MATERIALS: Before each daily radiotherapy session, the positioning of 28 patients was set up using an optical positioning system. After this initial setup, the patients underwent standard on-board imaging that included daily orthogonal kilovoltage images and weekly cone beam computed tomography scans. Daily translational shifts were made after comparing the on-board images with the treatment planning computed tomography scans. These daily translational shifts represented the daily positional error in the optical tracking system and were recorded during the treatment course. For 13 patients treated with smaller fields, a three-degree of freedom (3DOF) head positioner was used for more accurate setup. RESULTS: The mean positional error for the optically guided system in patients with and without the 3DOF head positioner was 1.4 ± 1.1 mm and 3.9 ± 1.6 mm, respectively (p <.0001). The mean positional error drifted 0.11 mm/wk upward during the treatment course for patients using the 3DOF head positioner (p = .057). No positional drift was observed in the patients without the 3DOF head positioner. CONCLUSION: Our initial clinical experience with optically guided head-and-neck fractionated radiotherapy was promising and demonstrated clinical feasibility. The optically guided setup was especially useful when used in conjunction with the 3DOF head positioner and when it was recalibrated to the shifts using the weekly portal images.

Head and neck cancer-specific survival based on socioeconomic status in Asians and Pacific Islanders.

BACKGROUND: Lower socioeconomic status (SES) has been linked to higher incidence of head and neck cancer (HNC) and lower survival. However, little is known about the effect of SES on HNC survival in Asians and Pacific Islanders (APIs). This study's purpose was to examine the effect of SES on disease-specific survival (DSS) and overall survival (OS) in APIs with HNC using population-based data. METHODS: A total of 53,544 HNC patients (4,711 = APIs) were identified from the California Cancer Registry from 1988 to 2007. Neighborhood (block-group-level) SES, based on composite Census 1990 and 2000 data, was calculated for each patient based on address at diagnosis, categorized into statewide quintiles, and collapsed into 2 groups for comparison (low SES = quintiles 1-3; high SES = quintiles 4-5). DSS and OS were computed by the Kaplan-Meier method. Adjusted hazards ratios (HR) were estimated using Cox proportional hazards regression models. RESULTS: Among APIs, lower neighborhood SES was significantly associated with poorer DSS (HR range for oral cavity, oropharynx, or larynx/hypopharynx cancer, 1.07-1.34) and OS (HR, 1.13-1.37) after adjusting for patient and tumor characteristics. Lower SES was significantly associated with poorer survival in API with all HNC sites combined: DSS HR: 1.26 (95% confidence interval [CI], 1.08-1.48) and OS HR, 1.30 (95% CI, 1.16-1.45). CONCLUSIONS: Neighborhood SES was associated with longer DSS and OS in API with HNC. The effect of SES on HNC survival should be considered in future studies, and particular attention should be paid to clinical care of lower-SES HNC patients.