Clinical Acceptability of Automatically Generated Elective Lymph Node Volumes for Head and Neck Cancer Patients

PURPOSE/OBJECTIVE(S)

Manual contouring of head and neck lymph node levels is a time-intensive process prone to provider-specific variation. The purpose of this work is to generate a clinical segmentation tool while minimizing the amount of manual effort required by physicians to develop training datasets and review contours. Here we investigate an approach to curate, develop, and clinically validate an auto-contouring model for standard cervical lymph node volumes in the head and neck using a publicly available deep learning architecture. This model updates our previously validated tool to reflect modern practices in lymph node segmentation.

MATERIALS/METHODS

With the assistance of a resident physician, five radiation oncologists manually contoured individual lymph node levels on CT scans for three separate patients treated definitively with radiation or chemoradiation for oropharynx cancer, resulting in 15 unique ground truth cases. These cases were then used to train an nnUnet deep-learning model to generate automated contours for 32 additional cases. These 32 cases were reviewed, manually edited, and used to create the final model. Finally, the model was used to generate contours on the original 15 CT scans (testing cohort), and providers compared these automated contours with the ground-truth (manual) contours. Two blinded studies were performed. In a double-blinded fashion, providers were first asked to select which set of contours they would prefer to use in clinical practice as a starting point for actual cases. Second, they scored each contour on a Likert scale (1-5) to indicate clinical acceptability, ranging from completely unusable to usable without modification.

RESULTS

Across all lymph node levels (IA, IB, II, III, IV, V, RP), average Dice Similarity Coefficient ranged from 0.77 to 0.89 for AI vs manual contours in the testing cohort. These AI and manual lymph node contours were reviewed by 5 physicians each, resulting in 525 preference scores. Across all lymph nodes, the AI contour was superior to or equally preferred to the manual contours at rates ranging from 75% to 91% in the first blinded study. In the second blinded study, physician preference for the manual vs AI contour was statistically different for only the RP contours (p < 0.01). Thus, there was not a significant difference in clinical acceptability for nodal levels I-V for manual versus AI contours. Across all physician-generated contours, 82% were rated as usable with stylistic to no edits, and across all AI-generated contours, 92% were rated as usable with stylistic to no edits.

CONCLUSION

An approach to generate clinically acceptable automated contours for cervical lymph node levels in the head and neck was demonstrated. Furthermore, for nodal levels I-V, there was no significant difference in clinical acceptability in manual vs AI contours. Because we were able to generate and validate a model for each lymph node level individually, the output is applicable to a complete range of disease in which cervical lymph nodes are treated.

Proton Based Stereotactic Radiotherapy for Skull Base Patients: Dosimetric Comparison to 4 Modern Radiation Treatment Modalities

PURPOSE/OBJECTIVE(S)

Re-irradiation with ablative doses to a smaller target volume and strict critical structure constraint is a challenge for modern radiation planning and delivery systems. Several advanced radiation treatment techniques can be used for fractionated stereotactic ablative radiosurgery (FSRS) in select patients with unresectable recurrent head and neck tumors. In this study, in order to better understand the dosimetry advantage of each technique, we compare the stereotactic treatment plans of our new small spot size Hitachi proton treatment unit to those of CyberKnife stereotactic radiosurgery (CK), Gamma Knife radiosurgery (GK), volumetric modulated arc therapy (VMAT), and MR Linac radiotherapy (MRL).

MATERIALS/METHODS

Ten FSRS skull base patients treated at our institution using VMAT (n = 5) or GK (n = 5) techniques. Intensity-modulated proton therapy (IMPT) plans were created in Raystation using Monte Carlo dose calculation algorithm. VMAT, CK, GK and MRL plans were generated in RayStation, Accuray Precision, Leksell Gamma Plan, and Monaco treatment planning systems, separately. Planning goals were to achieve the best target coverage of prescribed dose without compromising the critical organs at risk dose volume constraints of the clinical treatment plans. Plans were compared based on percent CTV coverage, Paddick conformity index (PCI), gradient index (GI, V50/V100), dose homogeneity index (HI, (D2-D98)/D50), low dose bath volume (LDBV, ratio of total volume irradiated between 20% and 50% prescription dose and the target volume), beam-on-time (BOT), and mean/maximum doses to brainstems.

RESULTS

The median target volume was 15.5 cm3 (range 1.0 - 36.23 cm3). The prescription was 45 Gy in 5 fractions for VMAT patients, and 21 - 27 Gy in 3 fractions for GK patients. The comparison of the treatment plans of these 5 delivery modalities was shown in table. All techniques achieved comparable CTV coverage. GI was superior for GK plans and outstanding in CK and IMPT plans. IMPT plans were also outstanding in regard to BOT and PCI. Significantly improved HI, LDBV and brainstem mean doses were achieved in IMPT plans. For adjacent brainstem and other OARs, maximum doses were comparable among all techniques.

CONCLUSION

In these five advanced radiation therapy modalities, proton therapy SBRT showed dosimetric advantage over other modalities to spare nearby OARs without sacrifice of target coverage. Further studies are needed to utilize this clinical benefit and investigate plan robustness.

Definitive Radiotherapy for Oligometastatic and Oligoprogressive Thyroid Cancer

PURPOSE/OBJECTIVE(S)

Local consolidative radiotherapy (LCT) for oligometastatic disease is a promising paradigm improving outcomes for various malignancies but has been underexplored for metastatic thyroid cancer. We hypothesize that LCT to distant sites with definitive RT doses can yield favorable outcomes and defer systemic therapy escalation for these patients.

MATERIALS/METHODS

We reviewed 96 thyroid cancer patients who received 175 LCT courses from 2010-2022 to 228 metastatic sites, including: thorax (45%), bone (40%), brain (6%), head/neck (5%), and abdomen (3%). Common prescriptions were 50-55Gy/4-5fxs or 56-70Gy/8-10fxs for lung; 52.5-60Gy/15fxs for mediastinum; and 18-24Gy/1fx or 27-30Gy/3fxs for bone. RECIST v1.1 and CTCAE v5.0 were used to define progression and toxicities, respectively. Outcomes were evaluated via Kaplan-Meier and associations examined via Cox proportional hazards modeling.

RESULTS

Median age was 63 years (range: 26-92), with 62 oligometastatic cases (total 1-5 sites) and 34 oligoprogressive (with 1-5 growing sites). Primary disease was controlled in all patients, with 39% receiving post-op RT and 66% prior RAI. Histologies included papillary (40%), anaplastic (25%), follicular (12%), medullary (9%), Hurthle (7%), and poorly-differentiated (7%). Median time from initial diagnosis to LCT was 3 yrs (IQR 1-8), and median follow-up from 1st LCT was 21 mos (IQR 9-51). Patients received an average 2 LCT courses (range 1-8) treating 1-4 sites. Median survival (OS) from 1st LCT was 9 yrs (95% CI = 5-14). On multivariable analysis (MVA), worse OS was associated with anaplastic histology (HR 4.6, p<.01), but longer OS was associated with prior RAI (HR 0.33, p = .02) and oligometastatic disease (HR 0.3, p = .01). For anaplastic histology, median OS was 1.2 years vs. 9.3 years for non-anaplastic; 3-yr OS was 36% vs. 88% (log-rank, p<.01). Five-year OS for oligometastatic cases was 75% vs 53% for oligoprogressive (log-rank, p = .04). Median progression free survival (PFS) from 1st LCT was 15.5 mos (95% C I = 11-20). On MVA for all LCT courses, time to any progression (TTP) was negatively associated with anaplastic histology (HR 1.7, p = .02) and 2nd or higher LCT course (HR 1.45, p = .05), but favorably associated with thoracic site (HR 0.49, p<.01). Following later LCT courses, median TTP was 11 mos vs 17 mos for initial LCT course (log-rank, p = .03). After LCT to lung/chest, TTP was 18.6 mos vs 9.5 mos for non-thoracic sites (log-rank, p<.01). Only 6% of failures occurred at previously treated lesions. Most LCT courses (67%) were without ongoing chemotherapy, while 25% entailed continuing the same regimen and 9% had planned treatment post-RT. There were 2 Grade 3 toxicities (pneumonitis and esophagitis) and no Grade 4-5 events.

CONCLUSION

With high local control rates and minimal toxicity, LCT can be a feasible strategy to defer systemic therapy escalation for oligometastatic and oligoprogressive thyroid cancer.

Disease Control and Toxicity Outcomes after Intraoperative HDR Brachytherapy for Neck Recurrences in Patients Previously Irradiated Head and Neck Cancer

PURPOSE/OBJECTIVE(S)

Despite recent advances in local and systemic therapies for head and neck squamous cell carcinomas (HNSCC), the most common types of treatment failure remain local and regional. Patients with HNSCC also have a higher risk of developing secondary head and neck tumors due to a field cancerization phenomenon. Treatment of these recurrences poses a challenge, particularly in patients having previously received full dose external beam radiotherapy (EBRT) to the head and neck region. This study evaluates the clinical outcomes of intraoperative Harrison-Anderson-Mick applicator (HAM) HDR brachytherapy (BT) after salvage neck dissection for neck recurrences in patients previously irradiated for HNSCC.

MATERIALS/METHODS

All patients having received HAM BT for HNSCC neck recurrences at a single institution were identified. Demographic, treatment, disease control and toxicity data were collected retrospectively. Toxicity was graded as per Common Terminology Criteria for Adverse events version 5. The Kaplan Meier method was used to assess overall survival (OS) and ipsilateral regional control (IRC) from the time of HAM BT.

RESULTS

Nineteen patients with regional recurrence of HNSCC were treated with HAM BT Ir-192 between July 2006 and June 2022, with a median follow-up for survival of 51.4 months (range: 2.5-186.7). The median BT dose was 12.5 Gy delivered intraoperatively at 5 mm tissue depth/1 cm from source. Fifteen patients (78.9%) also received postoperative EBRT to a median dose of 46 Gy in 23 fractions and 13 (68.4%) received systemic therapy. Six patients (31.6%) developed ipsilateral neck recurrences (4 who had adjuvant EBRT and 2 who did not), 2 patients had primary site recurrences and 5 patients developed distant metastases. In terms of acute toxicity, 4 patients had grade 3 dysphagia requiring feeding tube (FT) placement and one patient required surgical intervention for wound necrosis. In terms of late toxicity, 2 additional patients required FT placement and 1 was able to have it removed. No grade 4+ late toxicities were noted. The IRC at the site of HAM BT at 1 year was 71.5% and 63.6% at 5 years. The 1-year OS was 81.3% and 5-year OS was 40.9%.

CONCLUSION

Intraoperative HAM BT resulted in favorable rates of IRC with acceptable toxicity in the reirradiation setting for HNSCC.

Long-term outcomes of modern multidisciplinary management of sinonasal cancers: The M. D. Anderson experience

PURPOSE

To report long-term outcomes of modern radiotherapy for sinonasal cancers.

METHODS AND MATERIALS

A retrospective analysis of patients with sinonasal tumors treated with intensity-modulated radiotherapy or proton therapy. Multivariate analysis was used to determine predictive variables of progression free survival (PFS) and overall survival (OS).

RESULTS

Three hundred and eleven patients were included, with median follow-up of 75 months. The most common histologies were squamous cell (42%), adenoid cystic (15%), and sinonasal undifferentiated carcinoma (15%). Induction chemotherapy was administered to 47% of patients; 68% had adjuvant radiotherapy. Ten-year local control, regional control, distant metastasis free survival, PFS, and overall survival rates were 73%, 88%, 47%, 32%, and 51%, respectively. Age, non-nasal cavity tumor site, T3-4 stage, neck dissection, and radiation dose were predictive of PFS, while age, non-nasal cavity tumor site, T3-4 stage, positive margins, neck dissection, and use of neoadjuvant chemotherapy were predictive of OS. There was a 13% rate of late grade ≥3 toxicities.

CONCLUSION

This cohort of patients with sinonasal cancer treated with modern radiotherapy demonstrates favorable disease control rate and acceptable toxicity profile.

Stereotactic body ablative radiotherapy for reirradiation of small volume head and neck cancers is associated with prolonged survival: Large, single-institution, modern cohort study

BACKGROUND

Recurrent head and neck cancer has poor prognosis. Stereotactic body radiotherapy (SBRT) may improve outcomes by delivering ablative radiation doses.

METHODS

We reviewed patients who received definitive-intent SBRT reirradiation at our institution from 2013 to 2020. Patterns of failure, overall survival (OS), and toxicities were analyzed.

RESULTS

One hundred and thirty-seven patients were evaluated. The median OS was 44.3 months. The median SBRT dose was 45 Gy and median target volume 16.9 cc. The 1-year local, regional, and distant control was 78%, 66%, and 83%, respectively. Systemic therapy improved regional (p = 0.004) and distant control (p = 0.04) in nonmetastatic patients. Grade 3+ toxicities were more common at mucosal sites (p = 0.001) and with concurrent systemic therapy (p = 0.02).

CONCLUSIONS

In a large cohort of SBRT reirradiation for recurrent, small volume head and neck cancers, a median OS of 44.3 months was observed. Systemic therapy improved regional and distant control. Toxicities were modulated by anatomic site and systemic therapy.

Work Outcomes after Intensity-Modulated Proton Therapy (IMPT) versus Intensity-Modulated Photon Therapy (IMRT) for Oropharyngeal Cancer

Purpose

We compared work outcomes in patients with oropharyngeal cancer (OPC), randomized to intensity-modulated proton (IMPT) versus intensity-modulated photon therapy (IMRT) for chemoradiation therapy (CRT).

Patients and Methods

In 147 patients with stage II-IVB squamous cell OPC participating in patient-reported outcomes assessments, a prespecified secondary aim of a randomized phase II/III trial of IMPT (n = 69) versus IMRT (n = 78), we compared absenteeism, presenteeism (i.e., the extent to which an employee is not fully functional at work), and work productivity losses. We used the work productivity and activity impairment questionnaire at baseline (pre-CRT), at the end of CRT, and at 6 months, 1 year, and 2 years. A one-sided Cochran-Armitage test was used to analyze within-arm temporal trends, and a χ² test was used to compare between-arm differences. Among working patients, at each follow-up point, a 1-sided Wilcoxon rank-sum test was used to compare work-productivity scores.

Results

Patient characteristics in IMPT versus IMRT arms were similar. In the IMPT arm, within-arm analysis demonstrated that an increasing proportion of patients resumed working after IMPT, from 60% (40 of 67) pre-CRT and 71% (30 of 42) at 1 year to 78% (18 of 23) at 2 years (P = 0.025). In the IMRT arm, the proportion remained stable, with 57% (43 of 76) pre-CRT, 54% (21 of 39) at 1 year, and 52% (13 of 25) working at 2 years (P = 0.47). By 2 years after CRT, the between-arm difference between patients who had IMPT and those who had IMRT trended toward significance (P = 0.06). Regardless of treatment arm, among working patients, the most severe work impairments occurred from treatment initiation to the end of CRT, with significant recovery from absenteeism, presenteeism, and productivity impairments by the 2-year follow-up (P < 0.001 for all). Higher magnitudes of recovery from absenteeism (at 1 year, P = 0.05; and at 2 years, P = 0.04) and composite work impairment scores (at 1 year, P = 0.04; and at 2 years, P = 0.04) were seen in patients treated with IMPT versus those treated with IMRT.

Conclusion

In patients with OPC receiving curative CRT, patients randomized to IMPT demonstrated increasing work and productivity recovery trends. Studies are needed to identify mechanisms underlying head and neck CRT treatment causing work disability and impairment.

Defining the dose-volume criteria for laryngeal sparing in locally advanced oropharyngeal cancer utilizing split-field IMRT, whole-field IMRT and VMAT

PURPOSE

To determine the optimal dose-volume constraint for laryngeal sparing using three commonly employed intensity modulated radiation therapy (IMRT) approaches in patients with oropharyngeal cancer treated to the bilateral neck.

MATERIALS AND METHODS

Thirty patients with stage II-IVA oropharynx cancers received definitive radiotherapy with split-field IMRT (SF-IMRT) to the bilateral neck between 2008 and 2013. Each case was re-planned using whole-field IMRT (WF-IMRT) and volumetric modulated arc therapy (VMAT) and plan quality metrics and dose to laryngeal structures was evaluated. Two larynx volumes were defined and compared on the current study: the Radiation Therapy Oncology Group (RTOG) larynx as defined per the RTOG 1016 protocol and the MDACC larynx defined as the components of the larynx bounded by the superior and inferior extent of the thyroid cartilage.

RESULTS

Target coverage, conformity, and heterogeneity indices were similar in all techniques. The RTOG larynx mean dose was lower with WF-IMRT than SF-IMRT (22.1 vs 25.8 Gy; P < 0.01). The MDACC larynx mean dose was 17.5 Gy ± 5.4 Gy with no differences between the 3 techniques. WF-IMRT and VMAT plans were associated with lower mean doses to the supraglottic larynx (42.1 vs 41.2 vs 54.8 Gy; P < 0.01) and esophagus (18.1 vs 18.2 vs 36 Gy; P < 0.01).

CONCLUSIONS

Modern whole field techniques can provide effective laryngeal sparing in patients receiving radiotherapy to the bilateral neck for advanced oropharyngeal cancers.

SUMMARY

We evaluated laryngeal dose in patients with locally advanced oropharyngeal cancer treated to the bilateral neck using split-field IMRT (SF-IMRT), whole-field IMRT (WF-IMRT) and volumetric arc therapy (VMAT). All three techniques provided good sparing of laryngeal structures and were able to achieve a mean larynx dose < 33 Gy. There were no significant differences in dose to target structures or non-laryngeal organs at risk among techniques.

Neurologic sequelae following radiation with and without chemotherapy for oropharyngeal cancer: Patient reported outcomes study

BACKGROUND

There is little data describing neurocognitive late sequelae in patients treated for oropharyngeal cancer.

METHODS

Using PROs, scores for "numbness/tingling" and "difficulty remembering" were assessed. Wilcoxon testing was utilized to compare mean assessment scores (1-10) between treatment subgroups.

RESULTS

Four-hundred ninety-seven patients were evaluated and 267 (54%) received chemotherapy. The mean score for numbness/tingling for patients receiving radiation alone was 0.99 and for each chemotherapy subgroup were: Induction chemotherapy (IC), 1.35 (n = 99); concurrent chemotherapy (CCRT), 1.04 (n = 111) and IC + CCRT, 2.48 (n = 57); 30% of patients who received IC + CCRT had scores ≥5. The mean scores for difficulty remembering were XRT: 1.44, chemotherapy: 1.45, and IC + CCRT subgroup: 2.42.

CONCLUSIONS

The symptom burden related to peripheral neuropathy and cognitive complaints was minimal. A minority of patients reported high burdens. Particularly, 30% of patients receiving IC + CCRT described moderate to severe numbness/tingling.

Evaluation of the accuracy of deformable image registration on MRI with a physical phantom

Background and purpose

Magnetic resonance imaging (MRI) has gained popularity in radiation therapy simulation because it provides superior soft tissue contrast, which facilitates more accurate target delineation compared with computed tomography (CT) and does not expose the patient to ionizing radiation. However, image registration errors in commercial software have not been widely reported. Here we evaluated the accuracy of deformable image registration (DIR) by using a physical phantom for MRI.

Methods and materials

We used the “Wuphantom” for end‐to‐end testing of DIR accuracy for MRI. This acrylic phantom is filled with water and includes several fillable inserts to simulate various tissue shapes and properties. Deformations and changes in anatomic locations are simulated by changing the rotations of the phantom and inserts. We used Varian Velocity DIR software (v4.0) and CT (head and neck protocol) and MR (T1‐ and T2‐weighted head protocol) images to test DIR accuracy between image modalities (MRI vs CT) and within the same image modality (MRI vs MRI) in 11 rotation deformation scenarios. Large inserts filled with Mobil DTE oil were used to simulate fatty tissue, and small inserts filled with agarose gel were used to simulate tissues slightly denser than water (e.g., prostate). Contours of all inserts were generated before DIR to provide a baseline for contour size and shape. DIR was done with the MR Correctable Deformable DIR method, and all deformed contours were compared with the original contours. The Dice similarity coefficient (DSC) and mean distance to agreement (MDA) were used to quantitatively validate DIR accuracy. We also used large and small regions of interest (ROIs) during between‐modality DIR tests to simulate validation of DIR accuracy for organs at risk (OARs) and propagation of individual clinical target volume (CTV) contours.

Results

No significant differences in DIR accuracy were found for T1:T1 and T2:T2 comparisons (P > 0.05). DIR was less accurate for between‐modality comparisons than for same‐modality comparisons, and was less accurate for T1 vs CT than for T2 vs CT (P < 0.001). For between‐modality comparisons, use of a small ROI improved DIR accuracy for both T1 and T2 images.

Conclusion

The simple design of the Wuphantom allows seamless testing of DIR; here we validated the accuracy of MRI DIR in end‐to‐end testing. T2 images had superior DIR accuracy compared with T1 images. Use of small ROIs improves DIR accuracy for target contour propagation.

Quantifying the accuracy of deformable image registration for cone-beam computed tomography with a physical phantom

PURPOSE

Kilo-voltage cone-beam computed tomography (CBCT) is widely used for patient alignment, contour propagation, and adaptive treatment planning in radiation therapy. In this study, we evaluated the accuracy of deformable image registration (DIR) for CBCT under various imaging protocols with different noise and patient dose levels.

METHODS

A physical phantom previously developed to facilitate end-to-end testing of the DIR accuracy was used with Varian Velocity v4.0 software to evaluate the performance of image registration from CT to CT, CBCT to CT, and CBCT to CBCT. The phantom is acrylic and includes several inserts that simulate different tissue shapes and properties. Deformations and anatomic changes were simulated by changing the rotations of both the phantom and the inserts. CT images (from a head and neck protocol) and CBCT images (from pelvis, head and "Image Gently" protocols) were obtained with different image noise and dose levels. Large inserts were filled with Mobil DTE oil to simulate soft tissue, and small inserts were filled with bone materials. All inserts were contoured before the DIR process to provide a ground truth contour size and shape for comparison. After the DIR process, all deformed contours were compared with the originals using Dice similarity coefficient (DSC) and mean distance to agreement (MDA). Both large and small volume of interests (VOIs) for DIR volume selection were tested by simulating a DIR process that included whole patient image volume and clinical target volumes (CTV) only (for CTVs propagation).

RESULTS

For cross-modality DIR registration (CT to CBCT), the DSC were >0.8 and the MDA were <3 mm for CBCT pelvis, and CBCT head protocols. For CBCT to CBCT and CT to CT, the DIR accuracy was improved relative to the cross-modality tests. For smaller VOIs, the DSC were >0.8 and MDA <2 mm for all modalities.

CONCLUSIONS

The accuracy of DIR depends on the quality of the CBCT image at different dose and noise levels.

Prospective quantitative quality assurance and deformation estimation of MRI-CT image registration in simulation of head and neck radiotherapy patients

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MRI-CT deformable image registration was not superior to rigid registration.

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Dice similarity coefficients were 0.65, 0.62, and 0.63 for deformable registrations.

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Dice similarity coefficient was 0.63 for rigid registration.

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Registration quality was superior in muscle and gland compared to bone and vessel.

Background

MRI-guided radiotherapy planning (MRIgRT) may be superior to CT-guided planning in some instances owing to its improved soft tissue contrast. However, MR images do not communicate tissue electron density information necessary for dose calculation and therefore must either be co-registered to CT or algorithmically converted to synthetic CT. No robust quality assessment of commercially available MR-CT registration algorithms is yet available; thus we sought to quantify MR-CT registration formally.

Methods

Head and neck non-contrast CT and T2 MRI scans acquired with standard treatment immobilization techniques were prospectively acquired from 15 patients. Per scan, 35 anatomic regions of interest (ROIs) were manually segmented. MRIs were registered to CT rigidly (RIR) and by three commercially available deformable registration algorithms (DIR). Dice similarity coefficient (DSC), Hausdorff distance mean (HD mean) and Hausdorff distance max (HD max) metrics were calculated to assess concordance between MRI and CT segmentations. Each DIR algorithm was compared to DIR using the nonparametric Steel test with control for individual ROIs (n = 105 tests) and for all ROIs in aggregate (n = 3 tests). The influence of tissue type on registration fidelity was assessed using nonparametric Wilcoxon pairwise tests between ROIs grouped by tissue type (n = 12 tests). Bonferroni corrections were applied for multiple comparisons.

Results

No DIR algorithm improved the segmentation quality over RIR for any ROI nor all ROIs in aggregate (all p values >0.05). Muscle and gland ROIs were significantly more concordant than vessel and bone, but DIR remained non-different from RIR.

Conclusions

For MR-CT co-registration, our results question the utility and applicability of commercially available DIR over RIR alone. The poor overall performance also questions the feasibility of translating tissue electron density information to MRI by CT registration, rather than addressing this need with synthetic CT generation or bulk-density assignment.

Optimizing laryngeal sparing with intensity modulated radiotherapy or volumetric modulated arc therapy for unilateral tonsil cancer

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Early stage tonsillar cancers may be treated with unilateral neck radiotherapy (RT).

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We performed a dosimetric study comparing three common radiotherapy modalities.

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No significant differences in target coverage existed between all plans.

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Laryngeal doses were reduced using whole-field intensity modulated RT and VMAT.

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Shorter treatment times and required monitor units were also associated with VMAT.

Background and purpose

Minimizing radiation dose exposure to nearby organs is key to limiting clinical toxicities associated with radiotherapy. Several treatment modalities such as split- or whole-field intensity-modulated radiotherapy (SF-IMRT, WF-IMRT) and volumetric modulated arc therapy (VMAT) are being used to treat tonsillar cancer patients with unilateral neck radiotherapy. Herein, we provide a modern dosimetric comparison of all three techniques.

Materials and methods

Forty patients with tonsillar cancer treated with definitive, ipsilateral neck SF-IMRT were evaluated. Each patient was re-planned with WF-IMRT and VMAT techniques, and doses to selected organs-at-risk (OARs) including the larynx, esophagus, and brainstem were compared.

Results

No significant differences in target coverage existed between plans; however, the heterogeneity index improved using WF-IMRT and VMAT relative to SF-IMRT. Compared to SF-IMRT, WF-IMRT and VMAT plans had significantly lower mean doses to the supraglottic larynx (31 Gy, 18.5 Gy, 17 Gy; p < 0.01), the MDACC-defined larynx (13.4 Gy, 10.5 Gy, 9.8 Gy; p < 0.01), and RTOG-defined larynx (15.8 Gy, 12.1 Gy, 11.1 Gy; p < 0.01), respectively. Mean esophageal dose was lowest with SF-IMRT over WF-IMRT and VMAT (5.9 Gy, 12.2 Gy, 11.1 Gy; p < 0.01) but only in the absence of lower neck disease. On average, VMAT plans had shorter treatment times and required less monitor units than both SF-IMRT and WF-IMRT.

Conclusion

In the setting of unilateral neck radiotherapy, WF-IMRT and VMAT plans can be optimized to significantly improve dose sparing of critical structures compared to SF-IMRT. VMAT offers additional advantages of shorter treatment times and fewer required monitor units.

Long-term quality of life after definitive treatment of sinonasal and nasopharyngeal malignancies

OBJECTIVE

To evaluate long-term global and site-specific health-related quality of life (HRQoL) in patients treated for sinonasal and nasopharyngeal malignancies.

STUDY DESIGN

Cross-sectional.

METHODS

One hundred fourteen patients with sinonasal and nasopharyngeal malignancies received surgery, radiation, systemic chemotherapy, or a combination thereof, with curative intent. Validated global ([EuroQol-5D] Visual Analogue Scale [EQ-5D VAS]) and disease-specific instruments (MD Anderson Symptom Inventory-Head and Neck [MDASI-HN], Anterior Skull Base Questionnaire [ASBQ]) were administered to patients who were both free of disease and had completed treatment at least 12 months previously. Associations between instruments, instrument domains, and specific clinical parameters were analyzed.

RESULTS

The median age was 55 years. The mean EQ-5D VAS, MDASI-22 composite score, and ASBQ score were 74 (standard deviation [SD] 21), 48 (SD 36), and 130 (SD 27), respectively. The most frequently reported high-severity items in MDASI-HN were dry mouth and difficulty tasting food. The most frequently reported high-severity items in ASBQ were difficulty with smell and nasal secretions. Advanced Tumor (T) classification was associated with worse overall ASBQ sum score (P = 0.02). ASBQ performance at home and MDASI-HN drowsy symptom items independently predicted worse global HRQoL as measured by the EQ-5D VAS (P < 0.001).

CONCLUSION

Global HRQoL for survivors of sinonasal and nasopharyngeal malignancies after multimodality treatment approximates that of the U.S. population for the same age group. ASBQ and MDASI-HN correlate well with global HRQoL outcomes as measured by EQ-5D VAS. MDASI-HN and ASBQ elicited unique symptoms, highlighting the complex symptom burden experienced by these patients. Further studies should identify patients predisposed to reduced long-term QOL.

LEVEL OF EVIDENCE

3 Laryngoscope, 130:86-93, 2020.

Two-year prevalence of dysphagia and related outcomes in head and neck cancer survivors: An updated SEER-Medicare analysis

BACKGROUND

The aim of the study was to examine prevalence of dysphagia at the population level in head and neck cancer (HNC) survivors.

METHODS

Surveillance, Epidemiology, and End Results-Medicare claims among 16 194 patients with HNC (2002-2011) were analyzed to estimate 2-year prevalence of dysphagia, stricture, and aspiration pneumonia, and derive treatment- and site-specific estimates.

RESULTS

Prevalence of dysphagia, stricture, pneumonia, and aspiration pneumonia was 45.3% (95% confidence interval [CI]: 44.5-46.1), 10.2% (95% CI: 9.7-10.7), 26.3% (95% CI: 25.6-26.9), and 8.6% (95% CI: 8.2-9.1), respectively. Dysphagia increased by 11.7% over the 10-year period (P < .001). Prevalence was highest after chemoradiation and multimodality therapy.

CONCLUSION

Comparing to published rates using similar methodology the preceding decade (1992-1999), prevalence of dysphagia based on claims data was similar in 2002-2011 in this study. These results suggest persistence of dysphagia as a highly prevalent morbidity, even in the decade in which highly conformal radiotherapy and minimally invasive surgeries were popularized.

Magnetic Resonance-based Response Assessment and Dose Adaptation in Human Papilloma Virus Positive Tumors of the Oropharynx treated with Radiotherapy (MR-ADAPTOR): An R-IDEAL stage 2a-2b/Bayesian phase II trial

BACKGROUND

Current standard radiotherapy for oropharynx cancer (OPC) is associated with high rates of severe toxicities, shown to adversely impact patients' quality of life. Given excellent outcomes of human papilloma virus (HPV)-associated OPC and long-term survival of these typically young patients, treatment de-intensification aimed at improving survivorship while maintaining excellent disease control is now a central concern. The recent implementation of magnetic resonance image - guided radiotherapy (MRgRT) systems allows for individual tumor response assessment during treatment and offers possibility of personalized dose-reduction. In this 2-stage Bayesian phase II study, we propose to examine weekly radiotherapy dose-adaptation based on magnetic resonance imaging (MRI) evaluated tumor response. Individual patient's plan will be designed to optimize dose reduction to organs at risk and minimize locoregional failure probability based on serial MRI during RT. Our primary aim is to assess the non-inferiority of MRgRT dose adaptation for patients with low risk HPV-associated OPC compared to historical control, as measured by Bayesian posterior probability of locoregional control (LRC).

METHODS

Patients with T1-2 N0-2b (as per AJCC 7th Edition) HPV-positive OPC, with lymph node <3 cm and <10 pack-year smoking history planned for curative radiotherapy alone to a dose of 70 Gy in 33 fractions will be eligible. All patients will undergo pre-treatment MRI and at least weekly intra-treatment MRI. Patients undergoing MRgRT will have weekly adaptation of high dose planning target volume based on gross tumor volume response. The stage 1 of this study will enroll 15 patients to MRgRT dose adaptation. If LRC at 6 months with MRgRT dose adaptation is found sufficiently safe as per the Bayesian model, stage 2 of the protocol will expand enrollment to an additional 60 patients, randomized to either MRgRT or standard IMRT.

DISCUSSION

Multiple methods for safe treatment de-escalation in patients with HPV-positive OPC are currently being studied. By leveraging the ability of advanced MRI techniques to visualize tumor and soft tissues through the course of treatment, this protocol proposes a workflow for safe personalized radiation dose-reduction in good responders with radiosensitive tumors, while ensuring tumoricidal dose to more radioresistant tumors. MRgRT dose adaptation could translate in reduced long term radiation toxicities and improved survivorship while maintaining excellent LRC outcomes in favorable OPC.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT03224000; Registration date: 07/21/2017.

Intensity-Modulated Proton Therapy Adaptive Planning for Patients with Oropharyngeal Cancer

Purpose

The authors aimed to illustrate the potential dose differences to clinical target volumes (CTVs) and organs-at-risk (OARs) volumes after proton adaptive treatment planning was used.

Patients and Methods

The records of 10 patients with oropharyngeal cancer were retrospectively reviewed. Each patient's treatment plan was generated by using the Eclipse treatment planning system. Verification computed tomography (CT) scan was performed during the fourth week of treatment. Deformable image registrations were performed between the 2 CT image sets, and the CTVs and major OARs were transferred to the verification CT images to generate the adaptive plan. We compared the accumulated doses to CTVs and OARs between the original and adaptive plans, as well as between the adaptive and verification plans to simulate doses that would have been delivered if the adaptive plans were not used.

Results

Body contours were different on planning and week-4 verification CTs. Mean volumes of all CTVs were reduced by 4% to 8% (P ≤ .04), and the volumes of left and right parotid glands also decreased (by 11% to 12%, P ≤ .004). Brainstem and oral cavity volumes did not significantly differ (all P ≥ .14). All mean doses to the CTV were decreased for up to 7% (P ≤ .04), whereas mean doses to the right parotid and oral cavity increased from a range of 5% to 8% (P ≤ .03), respectively.

Conclusion

Verification and adaptive planning should be recommended during the course of proton therapy for patients with head and neck cancer to ensure adequate dose deliveries to the planned CTVs, while safe doses to OARs can be respected.

Patterns of locoregional failure following post-operative intensity-modulated radiotherapy to oral cavity cancer: quantitative spatial and dosimetric analysis using a deformable image registration workflow

Background

We sought to identify spatial/dosimetric patterns of failure for oral cavity cancer patients receiving post-operative IMRT (PO-IMRT).

Methods

Two hundred eighty-nine OCC patients receiving PO-IMRT were retrospectively reviewed from 2000 to 2012. Diagnostic CT documenting recurrence (rCT) was co-registered with planning CT (pCT) using a validated deformable image registration software. Manually segmented recurrent gross disease (rGTV) was deformed to co-registered pCTs. Mapped rGTVs were compared dosimetrically to planned dose and spatially to planning target volumes using centroid-based approaches. Failures types were classified using combined spatial/dosimetric criteria: A (central high-dose), B (peripheral high-dose), C (central intermediate/low-dose), D (peripheral intermediate/low-dose), and E (extraneous-dose).

Results

Fifty-four patients with recurrence were analyzed; 26 local recurrence, 19 regional recurrence, and 9 both local and regional recurrence. Median time to recurrence was 4 months (range 0–71). Median rGTVs volume was 3.7 cm³ (IQR 1.4–10.6). For spatial and dosimetric analysis of the patterns of failure, 30 patients (55.5%) were classified as type A (central high-dose). Non-central high dose failures were distributed as follows: 2 (3.7%) type B, 10 (18.5%) type C, 1 (1.8%) type D, and 9 (16.7%) type E. Non-IMRT failure in the matching low-neck field was seen in two patients. No failures were noted at the IMRT-supraclavicular field match-line.

Conclusions

Approximately half of patients with local/regional failure had non-central high dose recurrence. Peripheral high dose misses were uncommon reflecting adequate delineation and dose delivery. Future strategies are needed to reduce types C and E failures.

Electronic supplementary material

The online version of this article (doi:10.1186/s13014-017-0868-y) contains supplementary material, which is available to authorized users.

Clinical outcomes after local field conformal reirradiation of patients with retropharyngeal nodal metastasis

BACKGROUND

The purpose of this study was to present our experience with retropharyngeal node reirradiation using highly conformal radiotherapy (RT).

METHODS

A retrospective screen of 2504 consecutively irradiated patients with head and neck malignancies between 2005 and 2015 identified 19 patients who underwent reirradiation for retropharyngeal node metastasis. Clinical and toxicity outcomes were assessed in these patients.

RESULTS

Thirteen patients (68%) had squamous cell carcinoma. Eleven patients (58%) received conventionally fractionated intensity-modulated radiotherapy (IMRT) or proton therapy, and 8 patients (42%) received single-fractionated or hypofractionated stereotactic RT. Fourteen patients (74%) received chemotherapy. Median follow-up was 14.7 months. The 1-year local control, locoregional control, overall survival, and progression-free survival rates were 100%, 94%, 92%, and 92%, respectively. Three patients (16%) experienced acute grade 3 toxicity and occurred in those treated with IMRT. There was no late grade ≥3 toxicity.

CONCLUSION

Retropharyngeal node reirradiation with conformal therapy is well tolerated and associated with excellent short-term disease control.

Outcomes of oral cavity cancer patients treated with surgery followed by postoperative intensity modulated radiation therapy

OBJECTIVES

Although treatment paradigms have not changed significantly, radiotherapy, surgery, and imaging techniques have improved, leading us to investigate oncologic and survival outcomes for oral cavity squamous cell cancer (OCSCC) patients treated with surgery followed by postoperative IMRT.

MATERIAL AND METHODS

Records of patients with pathological diagnosis of OCSCC treated between 2000 and 2012 were retrospectively reviewed. Patients' demographic, disease, and treatment criteria were extracted. Kaplan-Meier method was used to calculate survival curves.

RESULTS

Two hundred eighty-nine patients were analyzed. Median follow-up was 35months. Two hundred sixty-eight had neck dissections (93%), of which 66% had nodal involvement, and 51% of those positive dissections had extracapsular extension. Forty patients received induction chemotherapy and 107 received concurrent chemotherapy. Median dose to high risk clinical target volume was 60Gy/30 fractions. The 5-year locoregional control and overall survival rates were 76% and 57%, respectively. Tumors with >1.5cm depth of invasion had significantly higher risk of local failure compared with ≤1.5cm (p<0.001). In multivariate analysis, positive and no neck dissection (p=0.01), positive lymphovascular invasion (p=0.006) and >1.5cm depth of invasion (p=0.003) were independent predictors of poorer survival.

CONCLUSIONS

Disease outcomes were consistent with historical data and did not appear compromised by the use of IMRT.

Delayed lower cranial neuropathy after oropharyngeal intensity-modulated radiotherapy: A cohort analysis and literature review

BACKGROUND

The purpose of this study was to examine swallowing-related lower cranial nerve palsy (LCNP) in oropharyngeal cancer (OPC) survivors after intensity-modulated radiotherapy (IMRT).

METHODS

Patients treated with definitive IMRT (66-72 Gy) were pooled from institutional trial databases. Prospective analyses on parent trials included videofluoroscopy, clinical LCNP examination, and questionnaires pre-IMRT, 6 months post-IMRT, 12 months post-IMRT, and 24 months post-IMRT. Time-to-event and incidence of LCNP was estimated with competing risk methods. Literature review (1977-2015) summarized published LCNP outcomes.

RESULTS

Three of 59 oropharyngeal cancer survivors with a minimum 2-year follow-up developed hypoglossal palsy ipsilateral to the index tumor (median latency 6.7 years; range 4.6-7.6 years). At a median of 5.7 years, cumulative incidence of LCNP was 5%. LCNP preceded progressive dysphagia in all cases. Published studies found median incidence of radiation-associated LCNP was 10.5% after NPC, but no OPC cancer-specific estimate.

CONCLUSION

Although uncommon, the potential for late LCNP preceding swallowing deterioration highlights the importance of long-term functional surveillance in OPC survivorship.

Cohort study of oncologic emergencies in patients with head and neck cancer

BACKGROUND

Treatments for head and neck squamous cell carcinoma (HNSCC) are associated with toxicities that lead to emergency department presentation.

METHODS

We utilized data from an ongoing prospective cohort of newly diagnosed, previously untreated patients (N = 298) with HNSCC to evaluate the association between clinical and epidemiologic factors and risk for and frequency of emergency department presentation. Time to event was calculated from the date of treatment initiation to emergency department presentation, date of death, or current date. Frequency of emergency department presentation was the sum of emergency department visits during the follow-up time.

RESULTS

History of hypertension, normal/underweight body mass index (BMI), and probable depression predicted increased risk for emergency department presentation. BMI and severe pain were associated with higher frequency of emergency department presentations.

CONCLUSION

Clinical and epidemiologic factors can help predict patients with HNSCC who will present to the emergency department. Such knowledge may improve treatment-related patient outcomes and quality of life. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1195-1204, 2017.

Recurrent oral cavity cancer: Patterns of failure after salvage multimodality therapy

BACKGROUND

We focused on a cohort of radiation naïve patients who had recurrent oral cavity cancer (recurrent OCC) to assess their outcomes with salvage multimodal therapy.

METHODS

A retrospective single institutional study was performed of patients with recurrent OCC. Disease recurrence and survival outcomes were assessed.

RESULTS

Seventy-eight patients were analyzed. All patients had salvage surgery and intensity-modulated radiotherapy (IMRT) and 74% had chemotherapy. Five-year overall survival, recurrence-free survival, and locoregional control rates were 59%, 60%, and 74%, respectively.

CONCLUSION

Outcomes of radiation naïve patients with recurrent OCC are fair, and seem similar with patients with locally advanced nonrecurrent OCC treated with multimodal therapy. © 2016 Wiley Periodicals, Inc. Head Neck 39: 633-638, 2017.

Improved setup and positioning accuracy using a three-point customized cushion/mask/bite-block immobilization system for stereotactic reirradiation of head and neck cancer

The purpose of this study was to investigate the setup and positioning uncertainty of a custom cushion/mask/bite‐block (CMB) immobilization system and determine PTV margin for image‐guided head and neck stereotactic ablative radiotherapy (HN‐SABR). We analyzed 105 treatment sessions among 21 patients treated with HN‐SABR for recurrent head and neck cancers using a custom CMB immobilization system. Initial patient setup was performed using the ExacTrac infrared (IR) tracking system and initial setup errors were based on comparison of ExacTrac IR tracking system to corrected online ExacTrac X‐rays images registered to treatment plans. Residual setup errors were determined using repeat verification X‐ray. The online ExacTrac corrections were compared to cone‐beam CT (CBCT) before treatment to assess agreement. Intrafractional positioning errors were determined using prebeam X‐rays. The systematic and random errors were analyzed. The initial translational setup errors were −0.8±1.3 mm, −0.8±1.6 mm, and 0.3±1.9 mm in AP, CC, and LR directions, respectively, with a three‐dimensional (3D) vector of 2.7±1.4 mm. The initial rotational errors were up to 2.4° if 6D couch is not available. CBCT agreed with ExacTrac X‐ray images to within 2 mm and 2.5°. The intrafractional uncertainties were 0.1±0.6 mm, 0.1±0.6 mm, and 0.2±0.5 mm in AP, CC, and LR directions, respectively, and 0.0∘±0.5°, 0.0∘±0.6°, and −0.1∘±0.4∘ in yaw, roll, and pitch direction, respectively. The translational vector was 0.9±0.6 mm. The calculated PTV margins mPTV(90,95) were within 1.6 mm when using image guidance for online setup correction. The use of image guidance for online setup correction, in combination with our customized CMB device, highly restricted target motion during treatments and provided robust immobilization to ensure minimum dose of 95% to target volume with 2.0 mm PTV margin for HN‐SABR.

PACS number(s): 87.55.ne

Assessing the Quality of a Radiation Oncology Case-Based, Peer-Review Program in an Integrated Academic and Community Cancer Center Network

Purpose:

Academic centers increasingly find a need to define a comprehensive peer-review program that can translate high-quality radiation therapy (RT) to community network sites. In this study, we describe the initial results of a quarterly quality audit program that aims to improve RT peer-review and provider educational processes across community sites.

Materials and Methods:

An electronic tool was used by community-based certified member (CM) sites to enter clinical treatment information about patients undergoing peer review. At least 10% of the patient load for each CM physician was selected for audit on a quarterly basis by expert academic faculty. Quality metrics included the review of the management plan, technical plan, and other indicators. RT was scored as being concordant or nonconcordant with institutional guidelines, national standards, or expert judgment.

Results:

A total of 719 patients were entered into the peer-review database by the first four CM sites. Of 14% of patients audited, 17% (18 of 104) were deemed nonconcordant. Nonconcordance rates were lowest in prevalent disease sites, such as breast (16%), colorectal (14%), and lung (12%), whereas rates were highest in lymphoma (50%), brain (44%), and gynecology (27%). Deficiencies included incomplete staging work-up, incorrect target and normal tissue delineation, and nonadherence to accepted dose-volume constraints.

Conclusion:

Given the high rate of nonconcordance, we recommend prospective, pre-RT peer review of all patients, and, in particular, expert review of patients that are from low-volume or complex disease sites. An integrated approach to peer review holds a promise of improving the quality, safety, and value of cancer therapy in the community setting.

Radiation therapy (with or without neck surgery) for phenotypic human papillomavirus-associated oropharyngeal cancer

BACKGROUND

Favorable outcomes for human papillomavirus-associated oropharyngeal cancer have led to interest in identifying a subgroup of patients with the lowest risk of disease recurrence after therapy. De-intensification of therapy for this group may result in survival outcomes that are similar to those associated with current therapy but with less toxicity. To advance this effort, this study analyzed the outcomes of oropharyngeal cancer patients treated with or without systemic therapy.

METHODS

This was a retrospective study of patients with oropharyngeal cancer treated between 1985 and 2012. The criteria for inclusion were ≤10 pack-years of cigarette smoking and stage III/IVA cancer limited to T1-3, N1-N2b, and T3N0 disease. A survival analysis was performed with the primary endpoint of progression-free survival (PFS).

RESULTS

The cohort included 857 patients. Systemic therapy was given to 439 patients (51%). The median survival was 80 months. The 2-year PFS rate was 91%. When the analysis was limited to 324 patients irradiated without systemic therapy, the 2- and 5-year PFS rates were 90% and 85%, respectively. Furthermore, for these 324 patients, the 5-year PFS rates for T1, T2, and T3 disease were 90%, 83%, and 70%, respectively. The 5-year PFS rate for patients treated with systemic therapy for T3 disease was 77% (P = .07).

CONCLUSIONS

According to the low-risk definition currently established in cooperative trials, the patients had a 2-year PFS rate approximating 90%. When patients who were treated with radiation alone were evaluated, no compromise was observed in this high rate of PFS, which is higher than the 2-year PFS thresholds used in current cooperative trials. Cancer 2016;122:1702-7. © 2016 American Cancer Society.

Disease control and toxicity outcomes for T4 carcinoma of the nasopharynx treated with intensity-modulated radiotherapy

BACKGROUND

Treatment of T4 nasopharyngeal carcinoma (NPC) is challenging because of the proximity of the tumor to the central nervous system. The purpose of this study was to present our evaluation of disease control and toxicity outcomes for patients with T4 NPC treated with intensity-modulated radiation therapy (IMRT) and chemotherapy.

METHODS

The medical records of 66 patients with T4 NPC treated from 2002 to 2012 with IMRT were reviewed. Endpoints included tumor control and toxicity outcomes (Common Terminology Criteria for Adverse Events [CTCAE v4.0]).

RESULTS

Median follow-up was 38 months. Five-year rates of locoregional control, distant metastasis-free survival, progression-free survival (PFS), and overall survival (OS) were 80%, 62%, 57%, and 69%, respectively. Nodal involvement was associated with worse PFS (p = .015). Gross target volume (GTV) volume >100 cm and planning target volume (PTV) volume >400 cm were associated with worse OS (p = .038 and p = .004, respectively). Four patients had significant cognitive impairment, and 9 had MRI evidence of brain necrosis.

CONCLUSION

For patients with T4 NPC treated with IMRT and chemotherapy, survival and locoregional disease control rates have improved; however, late treatment toxicity remains a concern. © 2015 Wiley Periodicals, Inc. Head Neck 38: E925-E933, 2016.

Management of the lymph node-positive neck in the patient with human papillomavirus-associated oropharyngeal cancer

BACKGROUND

The goal of the current study was to assess the rates of recurrence in the neck for patients with lymph node-positive human papillomavirus-associated cancer of the oropharynx who were treated with definitive radiotherapy (with or without chemotherapy).

METHODS

This is a single-institution retrospective study. Methodology included database search, and statistical testing including frequency analysis, Kaplan-Meier tests, and comparative tests including chi-square, logistic regression, and log-rank.

RESULTS

The cohort consisted of 401 patients with lymph node-positive disease who underwent radiotherapy between January 2006 and June 2012. A total of 388 patients had computed tomography restaging, and 251 had positron emission tomography and/or ultrasound as a component of their postradiation staging. Eighty patients (20%) underwent neck dissection, and 21 patients (26%) had a positive specimen. The rate of neck dissection increased with increasing lymph node stage, and was lower in patients who had positron emission tomography scans or ultrasound in addition to computed tomography restaging. The median follow-up was 30 months. The 2-year actuarial neck recurrence rate was 7% and 5%, respectively, in all patients and those with local control. Lymph node recurrence rates were greater in current smokers (P = .008). There was no difference in lymph node recurrence rates noted between patients who did and those who did not undergo a neck dissection (P = .4) CONCLUSIONS: A treatment strategy of (chemo)radiation with neck dissection performed based on response resulted in high rates of regional disease control in patients with human papillomavirus-associated oropharyngeal cancer.

Outcomes and patterns of care of patients with locally advanced oropharyngeal carcinoma treated in the early 21st century

Background

We performed this study to assess outcomes of patients with oropharyngeal cancer treated with modern therapy approaches.

Methods

Demographics, treatments and outcomes of patients diagnosed with Stage 3- 4B squamous carcinoma of the oropharynx, between 2000 – 2007 were tabulated and analyzed.

Results

The cohort consisted of 1046 patients. The 5- year actuarial overall survival, recurrence-free survival and local-regional control rates for the entire cohort were 78%, 77% and 87% respectively. More advanced disease, increasing T-stage and smoking were associated with higher rates of local-regional recurrence and poorer survival.

Conclusions

Patients with locally advanced oropharyngeal cancer have a relatively high survival rate. Patients’ demographics and primary tumor volume were very influential on these favorable outcomes. In particular, patients with small primary tumors did very well even when treatment was not intensified with the addition of chemotherapy.

Patterns of disease recurrence following treatment of oropharyngeal cancer with intensity modulated radiation therapy

PURPOSE

To report mature results of a large cohort of patients diagnosed with squamous cell carcinoma of the oropharynx who were treated with intensity modulated radiation therapy (IMRT).

METHODS AND MATERIALS

The database of patients irradiated at The University of Texas, M.D. Anderson Cancer Center was searched for patients diagnosed with oropharyngeal cancer and treated with IMRT between 2000 and 2007. A retrospective review of outcome data was performed.

RESULTS

The cohort consisted of 776 patients. One hundred fifty-nine patients (21%) were current smokers, 279 (36%) former smokers, and 337 (43%) never smokers. T and N categories and American Joint Committee on Cancer group stages were distributed as follows: T1/x, 288 (37%); T2, 288 (37%); T3, 113 (15%); T4, 87 (11%); N0, 88(12%); N1/x, 140 (18%); N2a, 101 (13%); N2b, 269 (35%); N2c, 122 (16%); and N3, 56 (7%); stage I, 18(2%); stage II, 40(5%); stage III, 150(19%); and stage IV, 568(74%). Seventy-one patients (10%) presented with nodes in level IV. Median follow-up was 54 months. The 5-year overall survival, locoregional control, and overall recurrence-free survival rates were 84%, 90%, and 82%, respectively. Primary site recurrence developed in 7% of patients, and neck recurrence with primary site control in 3%. We could only identify 12 patients (2%) who had locoregional recurrence outside the high-dose target volumes. Poorer survival rates were observed in current smokers, patients with larger primary (T) tumors and lower neck disease.

CONCLUSIONS

Patients with oropharyngeal cancer treated with IMRT have excellent disease control. Locoregional recurrence was uncommon, and most often occurred in the high dose volumes. Parotid sparing was accomplished in nearly all patients without compromising tumor coverage.

A myeloperoxidase polymorphism associated with reduced risk of lung cancer

Myeloperoxidase (MPO) is a metabolic/oxidative enzyme found in neutrophils and monocytes that contributes to pulmonary carcinogenesis through activation of specific procarcinogens including benzo[a]pyrene intermediates, 4-aminobiphenyl and the arylamines. There is a G-->A polymorphism located in the 5' untranslated region of the MPO gene that may be responsible for reduced transcriptional activity due to the decreased binding affinity for the SP1 transcription factor. Individuals with one or two copies of the A-allele may be afforded protection due to decreased transcriptional activity of MPO and subsequent decreased metabolic activation of procarcinogens. Previous studies have reported a range of protective effects in different ethnic populations. We employed a restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) assay to identify the MPO genotypes in 375 lung cancer cases and 378 healthy controls, all of whom were Caucasian. Our results demonstrate a reduced risk of lung cancer when the A-allele genotypes (G/A+A/A) were combined (odds ratio (OR)=0.66; 95% confidence interval (CI) 0.49-0.90). We also noted a protective effect (OR=0.63; 95% CI 0.45-0.87) in ever smokers with the A-allele genotypes which was not evident in never smokers (OR=1.14; 95% CI 0.42-3.11). We observed an incremental decrease in the protective effects as cigarette pack-years increased. Thus, lightest smokers were provided the greatest protection. When the data were stratified by gender, there was a statistically significant reduced risk of lung cancer among men (OR=0.55; 95% CI 0.36-0.84), but not among women (OR=0.81; 95% CI 0.55-1.26) for the A-allele genotypes. Lastly, an age effect was evident only in men but not women. The protective effects of the A-allele genotypes decreased with increasing age. This report provides further support for the hypothesis that a single nucleotide polymorphism in the MPO gene is a protective factor in lung cancer carcinogenesis.

Association between asbestos exposure, cigarette smoking, myeloperoxidase (MPO) genotypes, and lung cancer risk

BACKGROUND

As observed in tobacco-associated carcinogenesis, genetic factors such as the polymorphic metabolic/oxidative enzyme myeloperoxidase (MPO) could modulate individual susceptibility to asbestos-associated carcinogenesis.

METHODS

RFLP-PCR analysis identified the MPO genotypes in 375 Caucasian lung cancer cases and 378 matched controls. An epidemiological interview elicited detailed information regarding smoking history and occupational history and exposures.

RESULTS

Asbestos exposure was associated with a significantly elevated risk estimate (OR = 1.45; 95% CI 1.04-2.02). On stratified analysis, we found the MPO genotypes modified the effect of asbestos exposure on lung cancer risk. Specifically, G/G carriers who were exposed to asbestos had an odds ratio (OR) of 1.72 (95% CI; 1.09-2.66), while A-allele carriers (G/A + A/A) exposed to asbestos exhibited a reduced OR of 0.89 (95% CI; 0.56-1.44). The OR was further reduced to 0.73 (0.49-1.06) for A-allele carriers not exposed to asbestos. A similar trend was observed for the joint effects between the MPO genotypes and pack-years smoking. Next, all three risk factors (MPO genotypes, asbestos exposure, and smoking) were analyzed simultaneously for joint effects. Heavy smokers with the G/G genotype and a history of asbestos exposure demonstrated a statistically significant elevated risk estimate (OR = 2.19; 95% CI 1.16-4.11), while the A-allele carriers with the same exposure profile were at a lower risk for lung cancer (OR = 1.18; 95% CI 0.58-2.38). The A-allele genotypes demonstrated similar protective effects for the other three exposure profiles.

CONCLUSIONS

For a similar level of exposure to established carcinogens, individuals with the MPO A-allele genotypes appear to have a reduced risk of lung cancer.