Contralateral Neck Research Articles

Patterns of Failure and Clinical Outcomes of Post-operative Buccal Mucosa Cancers Treated with Ipsilateral Radiation Therapy

Loco-regional failure in carcinoma buccal mucosa (BM) after radical resection and adjuvant radiotherapy (RT) generally entails a bad prognosis. Usually, adjuvant RT (if indicated), is delivered to tumor bed and bilateral neck nodes. However, selected patients could be treated with ipsilateral RT to tumor bed and neck nodes (IL-RT). Literature on patterns of failure in this group of patients is sparse. We aimed to analyse the failure patterns and survival outcome in these cohort of patients treated at our institute. Eighty patients of post-operative BM cancers treated with IL-RT from June 2013 to May 2017 were included in this retrospective analysis. RT dose was 60-66 Gray in 30-33 fractions over 6-6.5 weeks delivered by linear accelerator using 3-dimensional conformal radiotherapy techniques. All outcomes were evaluated from the time of registration. Local, regional and loco-regional control was defined as time from registration to failure in tumor bed, regional nodes or both, respectively. Disease free survival (DFS) and overall survival (OS) were defined as time from registration to failure at any site (local, regional or distant) and death from any cause, respectively. Kaplan Meier method was used for all outcome analysis. The median age was 45.5 years (range 30-80). Patient characteristics are described in table 1. Median RT completion time and the overall treatment time were 6.2 weeks (range 5.9-7.1) and 11.6 weeks (range 8.5-19), respectively. 62 patients received 60 Gy, one patient 64 Gy and the rest received 66 Gy. The median follow-up time was 24.4 months (range 5-54.2).The 2-year local, regional and loco-regional control rates were 91.9%, 87.6% and 80.5%, respectively. The 2-year DFS and 2-year OS rates were 76.4% and 82.8%, respectively. The crude rates of failures at primary site, ipsilateral and contralateral neck were 12.5%, 12.5% and 3.7%, respectively. All patients with contralateral neck recurrence had N2 disease. Five patients (6.25%) had distant failures. Sixteen patients (20%) died of cancer and 2 patients died of non-malignant causes. The incidence of contralateral recurrence in BM cancer patients treated with primary surgery and adjuvant IL-RT is low. BM cancer with 1-3 risk factors may be treated with IL-RT, except, patients with N2 nodal status, who are at higher risk of contralateral regional recurrence.Abstract MO_23_2678; Table 1Patient CharacteristicsDistributionGender (Male: Female)75: 5T stage (T1: T2: T3: T4)10%: 43%: 26%: 21%N stage (N0: N1: N2)63%: 19%: 18%Overall TNM stage (I: II: III: IV) (As per AJCC 7th edition)5%: 30%: 23%: 42%Risk factors for post-operative RT (>pT3: pN+: PNI: LVI: Close margins: Tumor thickness)*52: 40: 18: 24: 13: 55Number of risk factors for post-op RT (1: 2: 3: >4)10%: 60%: 17.5%: 12.5%Grade (1: 2: 3)42: 34: 4*The total may not add up to 100% because of presence of multiple factors. Abbreviations: RT=Radiotherapy; PNI=Peri-neural invasion; LVI=Lympho-vascular invasion Open table in a new tab

Identifying risk factors for recurrence of papillary thyroid cancer in patients who underwent modified radical neck dissection

BackgroundPapillary thyroid cancer (PTC) patients with ipsilateral neck metastatic lymph node (LN) and those with contralateral neck metastatic LN belong to N1b. Only a few studies have reported on comparisons with regard to laterality of metastatic lateral LN. The aim of this study was to evaluate predictive factors for contralateral neck LN metastasis and to determine prognostic factors for recurrence in PTC patients with N1b.MethodsThis retrospective study reviewed the medical records of 390 PTC patients who underwent total thyroidectomy and central LN dissection plus ipsilateral or bilateral modified radical neck dissection (MRND) between January 2004 and December 2012.ResultsDuring a median follow-up of 81 (range, 6–156) months, 84 patients had a recurrence in any lesion. Male gender, a main tumor of more than 2 cm, number of metastatic central LN, number of harvested and metastatic lateral LN, total LN ratio, multifocality, bilaterality, and gross ETE had significance in the patients who underwent bilateral MRND. In multivariate analysis according to recurrence, patients with LN ratio > 0.44 in the central compartment (hazard ratio [HR], 1.890; 95% confidence interval [CI], 1.124–3.178; p = 0.015), LN ratio > 0.29 in the lateral compartment (HR, 2.351; 95% CI, 1.477–3.743; p < 0.001), and multifocality (HR, 1.583; 95% CI, 1.030–2.431; p = 0.036) were associated with worse RFS. However, the type of MRND was statistically significant only in univariate analysis.ConclusionsRecurrence in N1b PTC patients is predicted by central neck LN ratio > 0.44, lateral neck LN ratio > 0.29, and multifocality of tumors. We suggest that patients with these factors should receive short-term follow-up using image modalities like ultrasonography and computed tomography.

Nodal failure patterns and utility of elective nodal irradiation in submandibular gland carcinoma treated with postoperative radiotherapy - a multicenter experience

BackgroundThe patterns of nodal relapse in submandibular gland carcinoma (SMGC) patients treated with postoperative radiotherapy (PORT) remain unclear. This study aims to investigate the nodal failure patterns and the utility of elective nodal irradiation (ENI) in SMGC patients undergoing PORT.MethodsWe retrospectively enrolled 65 SMGC patients who underwent PORT between 2000 and 2014. The nodal failure sites in relation to irradiation fields and pathological parameters were analyzed. ENI regions were categorized into three bilateral echelons (first, levels I–II; second, level III; and third, levels IV–V). Extended ENI was defined as coverage of at least the immediately adjacent uninvolved echelons bilaterally; otherwise, limited ENI was administered.ResultsThirty patients (46%) were stage III–IV, and 18 (28%) were pN+. Neck irradiation included limited (72%) and extended ENI (28%). With a median follow-up of 79 months, 11 patients (17%) developed nodal failures (ipsilateral, N = 6; contralateral, N = 7), 7 (64%) of whom relapsed in the adjacent uninvolved echelons. We identified pN+ (P = 0.030), extranodal extension (ENE, P = 0.002), pT3–4 (P = 0.021), and lymphovascular invasion (LVI, P = 0.004) as significant predictors of contralateral neck recurrence. Extended ENI significantly improved regional control (RC) in patients with pN+ (P = 0.003), ENE (P = 0.022), pT3–4 (P = 0.044), and LVI (P = 0.014), and improved disease-free survival (DFS) in patients with pN+ (P = 0.034). For patients with ≥2 coincident adverse factors, extended ENI significantly increased RC (P < 0.001), distant metastasis-free survival (P = 0.019), and DFS (P = 0.007); conversely, no nodal recurrence was observed in patients without these adverse factors, even when only the involved echelon was irradiated.ConclusionsNodal failure is not uncommon in SMGC patients treated with PORT if pN+, ENE, pT3–4, and LVI are present. Extended ENI should be considered, particularly in patients with multiple pathological adverse factors.

Optimal timing of fluorine-18-fluoromisonidazole positron emission tomography/computed tomography for assessment of tumor hypoxia in patients with head and neck squamous cell carcinoma.

The aim of this study was to identify the optimal timing of fluorine-18-fluoromisonidazole (F-MISO) PET/CT imaging to assess hypoxia in patients with head and neck squamous cell carcinoma. Eighteen patients underwent pretreatment F-MISO PET/CT imaging after providing written informed consent. PET scans were acquired at 1, 3, and 5 h after injection of the radionuclide. The mean standardized uptake value (SUV) within a spherical region of interest placed on the contralateral neck musculature at the level of the largest tumor dimension was labeled as background. A value 1.5 times the background was deemed the threshold for significant hypoxia. Using this threshold, volumetric regions of interest encompassing the tumor were placed and hypoxic tumor volume (HTV) was generated for the primary tumor. Repeated-measures analysis of variance was used to compare the F-MISO PET/CT metrics across the three time-points. The volume of the primary tumor was also correlated with HTV. The mean SUV of the background decreased consistently over time, resulting in increased focality of F-MISO uptake in the tumor tissues. Analysis of variance showed statistically significant differences in the mean SUV measurements of the background between the 1-h and the 3-h time-points (P=0.034) as well as the 1-h and the 5-h time-points (P=0.034). In parallel, the mean HTV increased from 1.72 cm at 1 h after injection to 6.52 cm at 3 h and further to 7.24 cm at 5 h, with a statistically significant difference between the 1-h and the 3-h scans (P=0.023) and the 1-h and the 5-h scans (P=0.023). There was a moderately good positive correlation between gross tumor volume on planning computed tompography (CT) and HTV at 3 h on the F-MISO scan (Pearson's correlation co-efficient 'r'=+0.753; P<0.0001). The contrast resolution of F-MISO PET/CT scans in head and neck squamous cell carcinoma is suboptimal with early image acquisition, but improves significantly after delayed imaging. Increasing volume of tumor at the primary site is associated with an increase in hypoxia.

SPECT/CT-guided elective nodal irradiation for head and neck cancer: Estimation of clinical benefits using NTCP models

Background and purposeThe great majority of patients with lateralized head and neck squamous cell carcinoma (HNSCC) treated with radiotherapy routinely undergo bilateral elective nodal irradiation (ENI), even though the incidence of contralateral regional failure after unilateral ENI is low. Excluding the contralateral neck from elective irradiation could reduce radiation-related toxicity and improve quality-of-life. The current study investigated the dosimetric benefits of a novel approach using lymph drainage mapping by SPECT/CT to select patients for unilateral ENI. Patients and methodsForty patients with lateralized cT1-3N0-2bM0 HNSCC underwent lymph drainage mapping. Two radiation plans were made; the real plan with which patients were actually treated (selective SPECT/CT-guided plan irradiating the ipsilateral neck ± any contralateral draining level); and the virtual plan (standard plan according to institutional guidelines, as if the same patient would have been treated bilaterally). Radiation doses to clinically important organs-at-risk were compared between the two plans. We used five normal tissue complication probability (NTCP) models to predict the clinical benefits of this approach. ResultsMedian dose reductions to the contralateral parotid gland, contralateral submandibular gland, glottic larynx, supraglottic larynx, constrictor muscle and thyroid gland were 19.2, 27.3, 11.4, 9.7, 12.1 and 18.4 Gy, respectively. Median NTCP reductions for xerostomia, contralateral parotid function, dysphagia, hypothyroidism and laryngeal edema were 20%, 14%, 10%, 20% and 5% respectively. ConclusionsSelective SPECT/CT-guided ENI results in significant dose reductions to various organs-at-risk and corresponding NTCP values, and will subsequently reduce the incidence and severity of different troublesome radiation-related toxicities and improve quality-of-life.

SPECT/CT-guided lymph drainage mapping for the planning of unilateral elective nodal irradiation in head and neck squamous cell carcinoma.

To investigate the feasibility of lymph drainage mapping (LDM) using SPECT/CT to help select head and neck cancer (HNSCC) patients for unilateral elective neck irradiation (ENI). Patients with lateralized HNSCC treated with radiotherapy routinely undergo bilateral ENI, despite the incidence of contralateral regional failure being relatively low even after unilateral ENI. We hypothesized that patients with a lateralized tumor without visible lymph drainage to the contralateral neck have an extremely low risk of contralateral involved nodes. Excluding the contralateral neck from elective irradiation will reduce radiation-induced toxicity and improve quality-of-life. Fifty-five patients with lateralized cT1-3N0-2bM0 HNSCC not crossing the midline underwent LDM. Radiolabeled 99mTc-nanocolloid was injected in 4-5 depots around and in the primary tumor. Lymph drainage patterns were visualized using planar scintigraphy and SPECT/CT after 4h. We report on the incidence of contralateral drainage, the location of draining areas, and the size of underlying nodes. Lymphatic drainage was successfully visualized in 54 patients (98%). In 11 patients (20%) with visible contralateral drainage, 14 draining areas (16 nodes; median volume 0.50cc, diameter 8.0mm) were identified. Neck levels with contralateral drainage were level II (88%), III (25%), and IV (13%). Contralateral drainage was significantly higher in T3 compared to T1-2 tumors (45 and 14%, respectively, P = 0.035). SPECT/CT-guided LDM is feasible and can be used to guide unilateral ENI in HNSCC patients in prospective studies. In addition, the anatomical confidence in visualization of contralateral drainage indicates a potential for ENI limited to draining levels alone.

Metastatic neck node: a straying journey to diagnosis

&lt;p class="abstract"&gt;Squamous cell carcinoma of lung is most commonly associated with smoking. Its metastasis to contralateral neck node as the first presenting symptom is very rare. Tuberculosis (TB) and cancer of lung have causal relationship. There may also be coexistence of another neoplasm around the time of diagnosis of primary neoplasm. We present a case report of an 80 years old man who presented with a contralateral metastatic neck node. He was diagnosed to have coexistent lung cancer and pulmonary TB. In this journey towards diagnosis, the findings suggestive of tubercular larynx might have been a sequel of pulmonary TB.&lt;/p&gt;

Submandibular gland sparing when irradiating neck level IB in the treatment of oral squamous cell carcinoma

Patients with oral squamous cell carcinoma (OSqCCA) frequently require postoperative radiation (PORT), which may include contralateral level IB within the clinical target volume (CTV). The submandibular gland (SMG) is typically included within the level IB CTV; however, the SMG does not contain lymph nodes or lymphatic vessels. We hypothesized that level IB could be adequately irradiated while sparing the SMG to reduce xerostomia. Twelve patients with OSqCCA receiving PORT, which included the contralateral level IB within the planning target volume (PTV), were retrospectively reviewed and replanned using volumetric modulated arc therapy. CTV contouring, including contralateral level IB, was in accordance with the consensus contouring atlas but excluded the SMG. The contralateral neck PTVs were planned to 54 Gray (Gy) (PTV54). Dose requirements were per Radiation Therapy Oncology Group-1008: PTV54 D95% >54 Gy, with an allowable variation of >48.6 Gy. The dose constraint for the SMG was mean dose ≤39 Gy based on published dose-effect data for the SMGs. Mean SMG and PTV54 doses were 38.5 Gy and 56.3 Gy, respectively. Median PTV54 D95% was 53.0 Gy (range 52.5 to 54.6 Gy), with all cases meeting our allowable coverage goal. When assessing the portion of the PTV associated with level IB only (PTV_IB), mean PTV_IB dose was 54.4 Gy and median PTV_IB D95% was 43.3 Gy (range 42.5 to 52.2). Median D95% to CTV_IB was 50.2 Gy. SMG sparing resulted in 10% to 20% underdosing of the part of the PTV corresponding to level IB, as a portion of the PTV lies within the SMG. The SMG can be spared to a mean dose ≤39 Gy with slight underdosing of the surrounding PTV where the PTV overlaps with the SMG. Clinical trials evaluating SMG sparing are warranted.

Carbon nanoparticles guide contralateral central neck dissection in patients with papillary thyroid cancer.

The treatment of contralateral central neck lymph node metastasis is controversial in patients with papillary thyroid cancer. The present study reports the use of carbon nanoparticles (CNs) as lymph node tracers and discusses the potential role of predicting contralateral central neck metastasis is evaluated, so as to guide contralateral central neck dissection (CND). A total of 70 consecutive patients with papillary thyroid cancer were enrolled in the present study. All patients underwent a total or near-total thyroidectomy plus bilateral CND, during which CNs were used as a lymph node tracer. Of the 70 enrolled patients, 51 (72.86%) were confirmed to have lymph node metastasis in the central neck, 50 (71.43%) patients in the ipsilateral central neck and 14 (20.00%) in the contralateral central neck. A total of 579 (84.90%) lymph nodes were stained black by CNs. Of the 193 metastatic lymph nodes, 168 were located in the ipsilateral central compartment and the other 25 in the contralateral central compartment. A total of 147 (76.17%) metastatic lymph nodes were stained black. A total of 21 metastatic lymph nodes were found in the contralateral central compartment, 4 metastatic lymph nodes of contralateral central compartment were not black-stained. The sensitivity and specificity of CNs for contralateral metastasis was 84 and 25%, respectively. Contralateral central lymph node metastasis was significantly associated with extrathyroid extension and the presence of ipsilateral central neck lymph node metastasis. Together, the results of the present study reveal that CNs might accurately predict contralateral central lymph nodes metastasis and could be used to direct CND.

(OA29) Low Rate of Contralateral Neck Failure in T1-2N2B TONSIL PATIENTS Treated With Ipsilateral Neck Radiation

Treatment of advanced oropharyngeal carcinomas generally entails bilateral radiation therapy. However, multiple single institutional retrospective studies have demonstrated low rates of contralateral neck failure in patients treated with radiation to the primary tumor and ipsilateral neck for well-lateralized tonsil cancer with N0-N2a (up to 1 lymph node, LN) disease. Avoidance of the contralateral neck results in both decreased acute and long-term side effects from treatment, however this reduction in radiation field must be balanced against the possibility of increased local recurrence There is little data specifically examining the possibility of omission of contralateral neck radiation in tonsil patients with N2b disease (>1 small LN). The purpose of our study is to review the institutional experiences at The University of Cincinnati and the University of Texas, MD Anderson Cancer Center in treating patients specifically with T1-T2N2b squamous cell carcinoma of the tonsil with ipsilateral neck irradiation to evaluate the rates of contralateral neck failure and assess treatment-related toxicities. We retrospectively reviewed the records of patients with squamous cell carcinoma of the tonsil who received definitive radiation between 1999 and 2017 at The MD Anderson Cancer Center and The University of Cincinnati. A total of 86 patients with T1-T2N2b were included and all other T and N stages were excluded. Of the 86 patients, 57 patients were p16+, 2 were p16 negative, and 27 had unknown p16 status. The rate of contralateral neck failure was determined. Radiation-related acute and late toxicities were documented. Of the 86 patients treated with ipsilateral radiation, 2 patients failed in the contralateral neck, for an absolute contralateral neck failure rate of 2.5%. One patient failed in the contralateral neck 3.6 months after treatment and the other patient failed in the contralateral neck at 21.1 months. There were no other contralateral failures after 21.1 months. The median follow-up was 78.7 months (range 3.4 – 205 months). Both of the contralateral neck failures were successfully salvaged. One patient underwent a salvage neck dissection followed by adjuvant ipsilateral neck radiotherapy and the other was salvaged with contralateral neck radiation. There were two patients with disease recurrence within the treatment field; one patient had persistent disease at the end of treatment and the second patient was found to have an in-field recurrence at 9 months. 33% received concurrent chemotherapy and 15% received induction chemotherapy. 7% required a feeding tube at the end of treatment. The contralateral neck failure rate in T1-T2N2b tonsil patients treated with ipsilateral neck RT is low. Feeding tube requirement is also low compared to historical controls from randomized trials (ranging from 15-50%). Moreover, both of the patients in our study who recurred within the contralateral neck were successfully salvaged. As multiple ongoing studies attempt to de-escalate treatment in the HPV+ oropharyngeal cancer population to reduce morbidities of treatment, our data supports decreasing the treatment volume in an effort to minimize toxicity. Ipsilateral neck irradiation should be considered in patients with well-lateralized T1-T2N2b tonsillar cancer, particularly those that are HPV+.

(OA31) Patterns of Failure for Oral Cavity Squamous Cell Carcinoma Patients Receiving Post-Operative Radiotherapy +/- Chemotherapy

To analyze patterns of failure and evaluate treatment outcomes for oral cavity cancer patients undergoing surgery and post-operative intensity-modulated radiotherapy (IMRT) with or without chemotherapy. We performed an analysis on patients with stage I-IVB oral cavity squamous cell carcinoma, treated with curative intent using primary surgery followed by radiotherapy +/- chemotherapy at our institution. When patients were treated with surgical flap reconstruction (pedicle or free flap), our institutional convention was to provide full coverage of the original tumor bed without requiring high dose coverage of the entire reconstruction graft. We analyzed patient survival as well as local and regional patterns of failure. This study was approved by our institutional review board. Survival data was available for 99 of 100 eligible patients, treated between 2000-2016, with median follow-up time of 39.4 months. The median survival for the entire cohort was 92.5 months (range 1.5-111.8). The 2-year overall survival, local control, and loco-regional control was 70%, 85% and 79%, respectively. The primary sites represented in this study were: oral tongue (43%), floor of mouth (18%), alveolus and hard palate (16%), retromolar trigone (12%) and lip (2%). Oral tongue (44.3%) and floor of mouth (18.6%) accounted for the majority of recurrences. Recurrence within the primary tumor bed alone was the most common pattern of failure (10 out of 26, 38.5%), while primary and ipsilateral neck recurrence occurred in 5 patients (19.2%) and 4 occurred in the contralateral neck alone (15.4%). On logistic regression, tumor grade, degree of alcohol use, floor of mouth primary, N2b nodal stage, and external beam dose were associated with recurrence (either local, regional or both) (p <0.05). Smoking pack-years approached significance (p = 0.06). Over half of the cohort (62 patients) had pedicle or free flaps to reconstruct the primary tumor bed, with 14 local failures. All failures occurred at the interface between the tumor bed and grafted tissue, with no failures beyond this interface. The loco-regional control rate following post-operative IMRT +/- chemotherapy in patients with oral cavity cancer in this series approaches 80%. The majority of patients who fail have a component of recurrence within the primary tumor bed. Routine treatment of the entire flap reconstruction may require large volume irradiation of normal tissues within the oral cavity with resultant toxicity. With a predominant failure pattern for oral cavity tumors within or directly adjacent to the original tumor bed, and rare recurrence within the flap reconstruction donor tissue itself, there is rationale to limit routine coverage of the entire flap particularly for aspects distant from the primary tumor. This is the approach we have used at our institution for 27 years with very low rates of tumor recurrence within flap reconstruction tissues.

Analysis of lymph node metastasis for hypopharyngeal carcinoma based on computed tomography

Objective To explore the pattern of lymph node metastasis and provide guidance for the delineation of clinical target volume for patients diagnosed with hypopharyngeal squamous cell carcinoma (HSCC). Methods A total of 123 patients who were initially diagnosed with HSCC by electrolaryngoscope and computed tomography (CT) of the head and neck in Shandong Tumor Hospital between 2014 and 2017 were recruited in this study. The lymph node metastasis was evaluated based on the diagnostic criteria of CT scan. The lymphatic metastasis ratio (LMR) at each node level was calculated. Analysis of variance (ANOVA) and χ2 test were used to analyze the relationship between LMR and primary tumors. Results Among 123 patients, primary tumors were originated from the pyriform sinus (PS) in 101 cases (82.1%), posterior pharyngeal wall (PPW) in 15(12.2%) and postcricoid (PC) in 7(5.7%), respectively. The overall LMR was calculated as 84.6%(n=104), in detail, 84.2% for patients with primary tumors originating from PS, 93.3% for those from PPW and 71.4% for patients from PC, respectively. For PS-derived tumors, the ipsilateral neck LMR at the level Ⅰa, Ⅰb, Ⅱa, Ⅱb, Ⅲ, Ⅳ, Ⅴ, Ⅵa, Ⅵb, and Ⅶ was 0, 3.0%, 66.3%, 42.6%, 46.5%, 10.9%, 5.0%, 2.0%, 7.9%, and 11.9%, respectively, and 0, 0, 14.9%, 5.0%, 3.0%, 2.0%, 0, 0, 3.0%, and 2.0% for the contralateral neck. For PPW tumors, the ipsilateral neck LMR at the level Ⅰa, Ⅰb, Ⅱa, Ⅱb, Ⅲ, Ⅳ, Ⅴ, Ⅵa, Ⅵb, and Ⅶ was 6.7%, 6.7%, 66.7%, 46.7%, 46.7%, 20.0%, 0, 13.3%, 33.3%, and 60.0%, respectively, and 6.7%, 6.7%, 33.3%, 26.7%, 20.0%, 20.0%, 0, 0, 13.3%, and 33.3% for the contralateral neck. For PC tumors, the ipsilateral neck LMR at the level Ⅱa, Ⅱb, Ⅲ, Ⅳ, Ⅴ and Ⅵb was 71.4%, 28.6%, 14.3%, 14.0%, 14.0%, and 14.3%, respectively, and the LMR at the level Ⅱa was 14.3% for the contralateral neck. No lymph node metastasis occurred in other lymph node levels. The mean levels of lymph node metastasis for the T1-T4 stage tumors were 2.4, 1.9, 2.2, 3.3 with statistical significance (P=0.023), and 2.2, 4.5 and 1.6 for patients with the tumors originated from PS, PPW and PC (P=0.000). The PPW invasion was significantly correlated with the level Ⅶ metastasis (P=0.000), and PC or esophageal invasion was intimately correlated with the level Ⅵ metastasis (P=0.002 and 0.001). Conclusions The most common lymphatic metastasis includes ipsilateral neck Ⅱa, Ⅲ, and Ⅱb, whereas the level Ⅰ and Ⅴ are rarely observed. For PPW-derived tumors, the LMR at the level Ⅶ is up to 60.0%. The incidence of PC or esophageal invasion enhances the risk of level Ⅵ lymph node metastasis. Key words: Hypopharyngeal carcinoma; Lymph node; Clinical target volume

Reducing Radiation Treatment Volumes in the N0 Contralateral Neck for HPV-Positive Oropharynx Patients

Reducing Radiation Treatment Volumes in the N0 Contralateral Neck for HPV-Positive Oropharynx Patients

Contralateral neck metastases in lateralised, resectable advanced stage oropharyngeal squamous cell carcinoma-Results of 57 patients undergoing bilateral selective neck dissection.

Contralateral neck metastases in lateralised, resectable advanced stage oropharyngeal squamous cell carcinoma-Results of 57 patients undergoing bilateral selective neck dissection.

Oropharynx-directed ipsilateral irradiation for p16-positive squamous cell carcinoma involving the cervical lymph nodes of unknown primary origin.

The purpose of this study was to present our findings on the use of limited-field, oropharynx-directed ipsilateral irradiation for p16-positive squamous cell carcinoma of unknown primary origin. Between April 2011 and January 2016, 25 patients with a histological diagnosis of p16-positive squamous cell carcinoma were selectively irradiated to the ipsilateral oropharynx and cervical neck for tumors of unknown primary origin. The dose to the oropharynx ranged from 54-60 Gy (median 60 Gy) in 30-33 fractions. Concurrent cisplatin-based chemotherapy was administered to 8 patients (32%). The actuarial 2-year estimates of locoregional control, progression-free survival, and overall survival were 91%, 87%, and 92%, respectively. One patient failed in the contralateral neck. There was no grade 3 + toxicity in either the acute or late setting. Oropharynx-directed, ipsilateral radiation results in disease control that compares favorably with historical controls treated by comprehensive mucosal and bilateral neck radiation.

Sparing the Submandibular Gland (SMG) When Treating Neck Level IB in Oral Squamous Cell Carcinoma (OSqCCA)

Patients with OSqCCA frequently have the ipsilateral SMG resected at neck dissection and require post-operative radiation (PORT) bilaterally. Contralateral level IB is often at risk and is included within the low risk clinical target volume (CTV). The NRG contouring atlas includes the SMG within the level IB target contour, and such inclusion is common practice. However, the lymphatic system develops prior to encapsulation of the parotid but after encapsulation of the submandibular and sublingual glands. At completion of embryogenesis, the parotid has lymph nodes and lymphatics within the capsule, whereas the submandibular and sublingual glands do not. Consequentially, surgical series report no metastases within the SMG even when level IB is involved. The SMG provides ≈ 66% of unstimulated saliva and SMG doses relate to xerostomia, as such, we hypothesized we could treat level IB while sparing the SMG without comprising target coverage. Twelve patients with OSqCCA undergoing neck dissection with indications for PORT including the contralateral level IB within the planning target volume (PTV) were retrospectively reviewed and re-planned. Neck nodal volume (CTVs) contouring, including level IB, were in accordance with the NRG contouring atlas but excluded the SMG. PTVs consisted of 3 mm uniform expansions of CTVs. The contralateral neck PTVs were planned to 54 Gy (PTV54). Dose requirements were per RTOG 1008: goal PTV54 D95%> 54 Gy, with an allowable variation of >48.6 Gy. The dose constraint for the SMG was mean dose < 39 Gy, found previously to preserve SMG saliva (Murdoch-Kinch CA et al, IJROBP 2008). Treatment plans were created utilizing volumetric modulated arc therapy. Pearson correlation coefficients assessed linear dependence between variables. Mean SMG volume was 8.6 cc and mean dose was 38.9 Gy (interquartile rage [IQR] 38.3-39.0). Mean PTV54 dose was 56.3 Gy (IQR 56.1-56.4). Median PTV54 D95% was 53.0 Gy (range 52.5-54.6 Gy), with all cases meeting our pre-specified allowable coverage goal. When assessing the portion of the PTV associated with level IB only (PTV_IB), mean PTV_IB dose was 53.7 Gy and median PTV_IB D95% was 43.3 Gy (range 42.5-44.8). Median D95% to CTV_IB was 50.2 Gy. SMG sparing resulted in an approximate 10-20% underdosing of the part of the PTV corresponding to level IB, as a small portion of the PTV volume lies within the SMG (the portion underdosed). The PTV54 D95%(Gy) was not correlated with PTV54 volume or SMG volume (both p >0.7), and PTV_IB D95%(Gy) was not correlated with PTV_IB or SMG volume (both p>0.15). The SMG can be spared to a mean dose < 39 Gy without compromising PTV coverage in patients receiving contralateral PORT including level IB for OSqCCA, with slight underdosing of the level IB PTV where it overlaps with the SMG. These principles also apply to cases where bilateral levels IB are targeted with intact SMGs.

Pathologic Risk Factors Associated With Contralateral Neck Disease in Patients with Tonsil Cancer: Implications on Patient Selection for Unilateral Neck Radiation Therapy

Pathologic Risk Factors Associated With Contralateral Neck Disease in Patients with Tonsil Cancer: Implications on Patient Selection for Unilateral Neck Radiation Therapy

Frequency of bilateral cervical metastases in hypopharyngeal squamous cell carcinoma: a retrospective analysis of 203 cases after bilateral neck dissection.

The decision whether to perform an elective neck dissection in patients with head and neck squamous cell carcinoma and clinically negative lymph nodes (cN0) is made based on the probability of micrometastases in the neck for the given subsite and size of the primary. A retrospective chart review was performed of 203 patients with hypopharyngeal SCC who received a bilateral neck dissection. The frequency of histologically unveiled bilateral neck metastases was determined. A high frequency of contralateral metastases above 20% was detected for all carcinomas affecting the midline and those involving the medial wall of the pyriform sinus except of T1-stages (13%) and a low frequency for laterally located primaries (3%). Ipsilateral nodal status predicted contralateral neck metastases. Bilateral neck dissection should be recommended for primaries affecting the midline and T2-4 tumors involving the medial wall of the pyriform sinus.

Volumetric analysis of olfactory neuroblastoma skull base laterality and implications on neck disease.

To determine if the laterality of primary tumors in patients with olfactory neuroblastoma (ONB) influenced the pattern and development of neck disease. Using a retrospective cohort study design from 1994 to 2015, the primary tumors of patients who either presented with or developed neck disease were volumetrically analyzed using iPlan software (version 3.0.0, BrainLAB, Feldkirchen, Germany) by two independent observers. Agreement of volume-derived sidedness was assessed with a kappa statistic, whereas agreement in volume-derived degree of tumor laterality was evaluated with an intraclass correlation coefficient. A one-sample t test was used to assess the difference in dominant percentage between the two observers. Sixty-one patients with histological diagnosis and treatment of ONB at our institution were identified. Twenty-four patients exhibited neck involvement, 13 of whom could be volumetrically analyzed. Tumors that were greater than 75% eccentric to one side all exhibited contralateral disease, whereas the majority of unilateral neck disease was associated with relatively midline masses. Within the entire cohort, ipsilateral level 2 lymph nodes displayed the highest involvement (83%, 20 of 24), followed by ipsilateral level 1 (54%, 13 of 24), contralateral level 2 (46%, 11 of 24), contralateral level 1 (21%, 5 of 24), and ipsilateral level 3 (21%, 5 of 24). Ipsilateral neck involvement frequently was observed; however, the degree of ONB primary site laterality did not appear to have implications on the development of contralateral neck disease. Therefore, when considering elective therapy to the neck, ONB laterality should not be used to justify unilateral neck treatment. 4. Laryngoscope, 128:864-870, 2018.

Post-operative therapy following transoral robotic surgery for unknown primary cancers of the head and neck

ObjectivesOur primary objective is to describe the post- operative management in patients with an unknown primary squamous cell carcinoma of the head and neck (HNSCC) treated with trans-oral robotic surgery (TORS). Materials & MethodsWe conducted a retrospective multi-institutional case series including all patients diagnosed with an unknown primary HNSCC who underwent TORS to identify the primary site from January 1, 2010 to June 30, 2016. We excluded those with recurrent disease, ≤6months of follow up from TORS, previous history of radiation therapy (RT) to the head and neck, or evidence of primary tumor site based on previous biopsies. Our main outcome measure was receipt of post-operative therapy. ResultsThe tumor was identified in 26/35 (74.3%) subjects. Post-TORS, 2 subjects did not receive adjuvant therapy due to favorable pathology. Volume reduction of RT mucosal site coverage was achieved in 12/26 (46.1%) subjects who had lateralizing tumors, ie. those confined to the palatine tonsil or glossotonsillar sulcus. In addition, for 8/26 (30.1%), the contralateral neck RT was also avoided. In 9 subjects, no primary was identified (pT0); four of these received RT to the involved ipsilateral neck nodal basin only without pharyngeal mucosal irradiation. ConclusionSurgical management of an unknown primary with TORS can lead to deintensification of adjuvant therapy including avoidance of chemotherapy and reduction in RT doses and volume. There was no increase in short term treatment failures. Treatment after TORS can vary significantly, thus we advocate adherence to NCCN guideline therapy post-TORS to avoid treatment-associated variability.