Positive Microscopic Margins Research Articles

Postoperative hyperfractionated IMRT with weekly cisplatin for head and neck cancer: phase IIa trial.

Postoperative chemoradiotherapy (POCRT) is the standard treatment for patients with head and neck squamous cell carcinoma (HNSCC) with high-risk features (positive microscopic margins and/or extranodal extensions). We hypothesized that dose escalation using hyperfractionation in intensity-modulated radiotherapy (HF-IMRT) improves POCRT outcomes; however, no prospective trial has assessed the feasibility of POCRT in HF. Therefore, we evaluated the feasibility of POCRT using HF-IMRT. HNSCC patients with positive microscopic margins and/or extranodal extension following surgery were included. HF-IMRT (73.6Gy in 64 fractions twice daily) was administered along with cisplatin at 40mg/m2 once a week for seven cycles during radiotherapy. The primary endpoint was the proportion of patients who completed treatment, which included the planned radiotherapy and the administration of ≥200mg/m2 of cisplatin. Feasibility was defined as the proportion of patients who completed treatment >60% using a one-sided binomial test. Ten patients were registered between October 2021 and April 2023. One patient was excluded because of tumor recurrence before POCRT. The median follow-up time was 18.2months, and the proportion of patients who completed treatment was 88.9%. The median total dose of cisplatin was 240mg/m2. The percentage of patients with grade 3 acute non-hematological adverse events was 77.8%. No patient experienced grade 4 or higher acute adverse events or grade 3 or higher late adverse events. POCRT using HF-IMRT is feasible for achieving adequate cisplatin doses and safe radiotherapy in patients with HNSCC.

Impact of renal cell cancer histology on outcomes of microscopic positive surgical margins and implications on post-surgical follow-up.

519 Background: Positive surgical margins (PSM) are associated with worsened survival outcomes in Renal Cell Carcinoma (RCC). Current AUA guidelines recommend intensified post-surgical follow-up and clinical vigilance in patients with PSM. We sought to evaluate outcomes of different RCC-histologies with microscopic-PSM. Methods: We performed a retrospective analysis of patients undergoing partial nephrectomy (PN) or radical nephrectomy (RN) for RCC who had microscopic-PSM. The cohort was divided according to RCC-Histology [Chromophobe-RCC (chRCC); Clear Cell-RCC (ccRCC); Papillary-RCC (pRCC) for descriptive and survival analyses. Primary outcome was all-cause mortality (ACM)/overall survival (OS). Secondary outcome was cancer-specific mortality (CSM)/cancer-specific survival (CSS). Cox proportional hazards multivariable analysis (MVA) was used to elucidate predictive factors for ACM and CSM. Kaplan-Meier Analysis (KMA) was performed to analyze 5-year OSS and CSS. Results: A total of 8100 patients were analyzed, and we identified 312 patients with microscopic-PSM [26 (8.3%), 236 (75.6%), and 50 (16.0%) of patients had chRCC, ccRCC, and pRCC respectively]. Cox-regression revealed ccRCC to be associated with worsened ACM (versus chRCC [referent] HR=7.8, p=0.042), and worsened CSM (versus chRCC [referent] HR=2.97, p=0.033); pRCC did not demonstrate worsened ACM (p=0.148) and CSM (p=0.201). Comparing chRCC, ccRCC, and pRCC, KMA revealed a 5-year OS of 91%, 87%, and 63%, (p=0.024) and 5-year CSS of 93%, 86%, and 65%. KMA comparing microscopic-PSM versus negative surgical margins (NSM) noted no significant difference in 5-year OS for chRCC (85% vs. 86%, p=0.365) or pRCC (80% vs. 84%, p=0.952), but significantly lower 5-year OS in microscopic-PSM in ccRCC (77% vs. 85%, p<0.001). Conclusions: In patients with microscopic-PSM, we noted significant differences according to histology, with ccRCC being associated with significantly worsened survival and mortality outcomes when compared to chRCC and pRCC; microscopic-PSM was also associated with significantly worsened survival compared to NSM in ccRCC, but not chRCC and pRCC. Microscopic-PSM can be considered to represent a higher risk subgroup in ccRCC but not chRCC or pRCC. Intensified post-surgical follow up compared to NSM patient is appropriate in ccRCC, while microscopic-PSM in chRCC and pRCC can be followed similarly to NSM patients with the same histology.

Correction: Risk factors and prognostic analysis of microscopic positive esophageal margins after radical surgery for proximal gastric cancer

Correction: Risk factors and prognostic analysis of microscopic positive esophageal margins after radical surgery for proximal gastric cancer

Risk factors and prognostic analysis of microscopic positive esophageal margins after radical surgery for proximal gastric cancer.

Proximal gastric cancer has been on the rise worldwide in recent years. A positive surgical margin may result in incomplete tumor and affect the prognosis of patients. This study aims to analyse the risk factors for and prognosis associated with microscopic positive esophageal margins (R1 resection) after radical surgery for proximal gastric cancer patients. This was a retrospective analysis of 316 patients with proximal gastric cancer who underwent surgical resection at the Department of Gastrointestinal Surgery of Hengshui People's Hospital from January 2013 to June 2018. Patients were divided into the R1 group (n = 24) and R0 group (n = 292) according to the esophageal margin status. Differences in clinicopathological characteristics and prognosis between the two groups were compared. Tumor location at the esophagogastric junction, Borrmann type 3/4, Lauren diffuse/mixed type, margin distance < 3cm, pT4 stage, and vascular invasion were identified as independent risk factors for positive esophageal margins in proximal gastric cancer patients (all P < 0.05). The 5-year overall survival rate was significantly lower in the R1 group than in the R0 group (45.8% vs. 64.2%, P < 0.05). Subgroup analysis revealed that the 5-year overall survival rate was significantly lower in the R1 group in the pT2-3 and pN0 stages (P < 0.05), while there was no significant difference in the pT4 and pN(+) stages (P > 0.05). Multivariate Cox regression analysis revealed that Borrmann type, Lauren type, pT stage, pN stage, and lymphovascular invasion were independent risk factors affecting the prognosis of patients with proximal gastric cancer (all P < 0.05), while esophageal margin status was not an independent risk factor affecting prognosis (P > 0.05). Positive esophageal margins in proximal gastric cancer are associated with various clinicopathological factors and lead to a worse prognosis in patients with pT2-3 and pN0 stages but do not affect the prognosis of patients with pT4 and pN(+) stages.

Endoscopic resection for esophageal granular cell tumors: report of 62 cases

BackgroundTo analyze the clinical manifestations, endoscopic features, pathological features, endoscopic resection, and prognosis of esophageal granular cell tumors (GCTs).MethodsThe present study retrospectively analyzed and followed up the clinical data of 62 patients diagnosed with esophageal GCTs who underwent endoscopic resection at Zhongshan Hospital of Fudan University between July 2007 and March 2022. The clinicopathological features, endoscopic diagnosis, and treatment experience of esophageal GCT patients were summarized.ResultsAmong the 62 patients with esophageal GCT, there were 34 males and 28 females, with an average age of 49.3 ± 11.7 years. Only 11 patients had symptoms, such as epigastric discomfort, regurgitation or dysphagia. One patient had multiple lesions, and the rest had single lesions, totaling 63 lesions. Most lesions (53/63) were located in the median and lower esophagus, the diameters ranged from 3 to 22 mm. The endoscopic morphology of the GCTs was molar, flat, hemispherical, or irregular submucosal protuberance. Endoscopic ultrasound (EUS) was performed in 38 cases, most cases (31/38) were hypoechoic, and 32 cases were appeared as homogeneous lesions. There were no complications during or after the endoscopic operations, and the en bloc resection rate was 100%. The negative rate of microscopic incisional margin was 63.5% (40/63). No patients developed recurrence during the follow-up period. The follow-up duration was 21–197 months (100.5 months for average).ConclusionEsophageal GCT is a rare disease with no obvious symptoms and a good prognosis. Endoscopic resection is a safe and effective method of diagnosis and treatment for esophageal GCTs. A microscopic positive tumor margin may not increase the rate of recurrence.

Real-World Experience of Clinical Outcomes of Microscopic Margin Positivity After Radical Gastrectomy from a Tertiary Cancer Center in Northeast India

Surgical resection for gastric adenocarcinoma (GAC) remains the only potentially curative treatment, and the use of neoadjuvant and adjuvant therapy improves survival in patients with advanced gastric cancer. Margin-positive resection is a known poor prognostic factor. A retrospective observational study of patients undergoing radical gastrectomy of any type for GAC was done at a tertiary care cancer center in Northeast India. The study included patients who were operated on from 1 January 2017 to 31 December 2021 (5 years), and they were followed up to 31 March 2024. A total of 172 patients underwent gastrectomy of any type for GAC during the study period of which 13 patients were found to have microscopic positive (R1) histopathological margin (7.6%). The median age of the patients with positive margins was 48 years (range 27 to 69 years). The male-to-female ratio was 9:4. Ten patients (77%) had poorly differentiated or signet-ring cell carcinoma. The distal margin was the most frequent margin which was positive (84.6%). Neoadjuvant chemotherapy was used in only 23.1% patients. At the end of our study period, only 1 patient out of 13 patients was alive. Median disease-free survival (DFS) was 16.2 months (95% confidence interval 1.2 to 31.1 months). Median overall survival (OS) was 20.2 months (95% confidence interval 9.3 to 31.2 months). Patients who have microscopic positive margins after gastrectomy are found to have a high incidence of poorly differentiated or signet-ring cell carcinoma.

358. IMPLICATIONS ON OVERALL SURVIVAL FROM POSITIVE CIRCUMFERENTIAL RESECTION MARGINS IN OESOPHAGEAL CANCER PATIENTS AT A TERTIARY REFERRAL CENTRE IN ENGLAND

Abstract Background The oesophagogastric (OG) tertiary referral centre at our Trust was established in March 2009.It caters to a catchment population of approximately 1.6 million. Oesophageal cancer is a morbid disease contributing to 18% of cancer mortalities worldwide. Involvement of circumferential resection margin (CRM) is an indicator of poor prognosis. The aim was to calculate the microscopic positive resection rate in patients undergoing resections for oesophageal cancers, assess disease free survival (DFS) and overall survival (OS) in this cohort. Methods Patients undergoing oesophageal resections for cancer at our OG unit who satisfied the inclusion criteria - age&amp;gt;18, operation with curative intent, adenocarcinoma and squamous cell cancer with a microscopic positive resection margin (R1) were included. Data was collected from the electronic patient record (Quadramed). Retrospective analysis was performed using MS Excel and IBM SPSS statistics Ver 27. Results A total of 640 oesophageal cancer resections performed between April 2009 - March 2023, who satisfied the inclusion criteria were included. Median age at surgery was 66 years. The R1 rate was 40% in our cohort (R0:R1 =380:260). Male to female ratio in the R1 cohort was 4:1. 98% (255 patients) had T3/T4 disease. 47.7% (124 patients developed recurrence. Of these, 83.8% (104 patients) developed distant metastasis and 16.2 %(20 patients) had locoregional metastasis. Median time to recurrence was 12 months and disease-free survival was also12 months. The OS at one year of 81% (140/260) was comparable to national data. Conclusion We conclude that locally advanced tumour staged T3 and above is the most likely cause for higher rate of CRM positivity. Other factors that could contribute is the lack of serosal layer in the oesophagus and the practise of ex situ removal of nodes from the main specimen in theatre which could potentially lead to stripping of the adventitia thus making the CRM falsely R1 during pathological staging. The R1 status however does not seem to affect the overall survival rate.

Total laparoscopic radical resection of hilar cholangiocarcinoma: preliminary experience of a single center

BackgroundThe aim of this study was to describe our preliminary experience in the procedure of laparoscopic radical resection of hilar cholangiocarcinoma and to evaluate its feasibility, safety, and clinical efficacy.MethodsA retrospective analysis was conducted on 44 patients with hilar cholangiocarcinoma who underwent laparoscopic surgery at our hospital from August 2019 to September 2023. Clinical data were collected from these patients, including 13 cases of Bismuth type I, 17 cases of Bismuth type II, 5 cases of Bismuth type IIIa, and 9 cases of Bismuth type IIIb.ResultsLaparoscopic radical resection of hilar cholangiocarcinoma was successfully performed in 38 patients (86.3%). Among the remaining patients, 3 required vascular reconstruction to complete radical surgery and were converted to laparotomies, while 3 others underwent T-tube drainage only due to unresectable metastases. The median operation time was 285 min (range, 190–450), and the median estimated blood loss was 360 mL (range, 260–1200). The postoperative hospital stay duration was 14.3 ± 3.6 days. No perioperative mortality was observed. Postoperative pathological examination revealed negative microscopic margins (R0) in 39 cases and positive microscopic margins (R1) in 2 cases. Postoperative complications occurred in 8 patients (18.1%), with 4 cases (9.0%) of Grade I, 3 cases (6.8%) of Grade II, 1 case (2.2%) of Grade IIIa, and no Grade IIIb or IV complications. The median overall survival for patients who underwent radical R0 resection was 30.4 months (range, 5.3–43.6). The Disease-free survival rates were 73.6% at 1 year, 61.2% at 2 years, and 40.1% at 3 years.ConclusionTotal laparoscopic radical resection of hilar cholangiocarcinoma can be performed safely, feasibly, and effectively by experienced surgeons after an accurate preoperative evaluation.

Clinical Outcome of Patients with Gastric, Duodenal, or Rectal Neuroendocrine Tumors after Incomplete Endoscopic Resection.

Objectives: Our aim was to investigate the clinical outcome of patients with well-differentiated gastric, duodenal, and rectal neuroendocrine tumors after treatment with incomplete endoscopic resection due to the finding of microscopic positive resection margins (R1). Methods: This is a retrospective analysis of consecutive patients with type 1 gastric, non-ampullary non-functioning duodenal, or rectal neuroendocrine neoplasms with positive R1 margins after endoscopic resection. The rate of tumor recurrence and progression-free survival were considered to be the study's main endpoints. Statistical analysis was performed using MedCalc® v.17 software and a p-value of <0.05 was considered significant. A Cox proportional-hazard regression was performed to identify risk factors for disease recurrence/progression. Results: After evaluating 110 patients, a total of 58 patients were included in the final analysis (15 gastric NENs, 12 duodenal NENs, and 31 rectal NENs). After evidence of endoscopic R1 resection had been gathered, 26 patients (44.8%) underwent an endoscopic/surgical extension of the previous resection. Tumor progression (all local recurrences) occurred in five out of fifty-eight patients (8.6%) with a median PFS of 36 months. There were no tumor-related deaths. G2 grading and the gastric primary tumor site were the only features significantly associated with the risk of recurrence of the disease (HR: 11.97 [95% CI: 1.22-116.99], HR: 12.54 [95% CI: 1.28-122.24], respectively). Conclusions: Tumor progression rarely occurs in patients with microscopic positive margin excision (R1) after endoscopic resection and does not seem to affect patients' clinical outcomes.

Oncologic Outcomes of Salvage Abdominoperineal Resection for Anal Squamous Cell Carcinoma Initially Managed with Chemoradiation.

Background: Abdominoperineal resection (APR) has been advocated for persistent or recurrent disease after failure of chemoradiation (CRT) for anal squamous cell cancer (SCC). Treatment with salvage APR can potentially achieve a cure. This study aimed to analyze oncological outcomes for salvage APR in a recent time period at a comprehensive cancer center. Methods: A retrospective review of all patients who underwent APR for biopsy-proven persistent or recurrent anal SCC between 1 January 2007 and 31 December 2020 was performed. Patients with stage IV disease at the time of initial diagnosis and patients with missing data were excluded. Univariate analysis was used with a chi-square test for categorical variables, and non-parametric tests were used for continuous variables. Kaplan-Meier survival analysis was performed to evaluate disease-specific (DSS), post-APR local recurrence-free (RFS), and disease-free survival (DFS). Results: A total of 96 patients were included in the analysis: 39 (41%) with persistent disease and 57 (59%) with recurrent SCC after chemoradiation had been completed. The median follow-up was 22 months (IQR 11-47). Forty-nine patients (51%) underwent extended APR and/or pelvic exenteration. Eight (8%) patients developed local recurrence, 30 (31%) developed local and distant recurrences, and 16 (17%) developed distant recurrences alone. The 3-year DSS, post-APR local recurrence-free survival, and disease-free survival were 53.8% (95% CI 43.5-66.5%), 54.5% (95% CI 44.4-66.8%), and 26.8% (95% CI 18.6-38.7%), respectively. In multivariate logistic regression analysis, positive microscopic margin (OR 10.0, 95% CI 2.16-46.12, p = 0.003), positive nodes in the surgical specimen (OR 9.19, 95% CI 1.99-42.52, p = 0.005), and lymphovascular invasion (OR 2.61 95% CI 1.05-6.51, p = 0.04) were associated with recurrence of disease. Gender, indication for APR (recurrent vs. persistent disease), HIV status, extent of surgery, or type of reconstruction did not influence survival outcomes. Twenty patients had targeted tumor-sequencing data available. Nine patients had PIK3CA mutations, seven of whom experienced a recurrence. Conclusions: Salvage APR for anal SCC after failed CRT was associated with poor disease-specific survival and low recurrence-free survival. Anal SCC patients undergoing salvage APR should be counseled that microscopic positive margins, positive lymph nodes, or the presence of lymphovascular invasion in the APR specimen are prognosticators for disease relapse. Our results accentuate the necessity for additional treatment strategies for the ongoing treatment challenge of persistent or recurrent anal SCC after failed CRT.

Risk Factors for Microscopic Disease Positivity at Ileocolic Resection Margins for Crohn's Disease.

Interest in microscopic margin positivity during surgical resection of medical-refractory Crohn's disease has been renewed with multiple recent studies showing an association between microscopic margin positivity with disease recurrence. Our aim was to determine risk factors for microscopic margin disease positivity following ileocolic resection (ICR). A prospectively-maintained database of patients with Crohn's disease undergoing ICR at a tertiary-referral center was queried. Margin positivity was defined as the presence of cryptitis, erosion, transmural inflammation with lymphoid aggregates, or architectural distortion at either ileal (proximal) or colonic (distal) margins. Amongst 584 patients, 97 patients had a positive microscopic margin (17%) of which 46% had a positive proximal margin, 17% had a positive distal margin, and 13% had both positive and distal margins. Using multivariable logistic regression analysis, index ICR was associated with less odds of positive margin (odds ratio [OR] 0.46, 95% confidence interval [CI] 0.24-0.89, p=0.02), and granuloma presence was associated with increased odds (OR 2.26, 95% CI 1.23-4.21, p=0.01). We found that repeat ileocolic resection and granuloma presence were predictors of microscopic margin disease.

Prognostic impact of positive microscopic margins (R1 resection) in patients with GIST (gastrointestinal stromal tumours): Results of a multicenter European study

Prognostic impact of positive microscopic margins (R1 resection) in patients with GIST (gastrointestinal stromal tumours): Results of a multicenter European study

Clinical and pathological factors associated with survival in patients with pancreatic cancer who receive adjuvant therapy after neoadjuvant therapy: A retrospective multi-institutional analysis

Clinical and pathological factors associated with survival in patients with pancreatic cancer who receive adjuvant therapy after neoadjuvant therapy: A retrospective multi-institutional analysis

A feasibility randomised-controlled-trial testing the use of indocyanine-green fluorescence image-guidance in liver surgery compared to standard liver surgery alone in reducing microscopic positive tumour margin Resection rate: the I-FIGS study

A feasibility randomised-controlled-trial testing the use of indocyanine-green fluorescence image-guidance in liver surgery compared to standard liver surgery alone in reducing microscopic positive tumour margin Resection rate: the I-FIGS study

In Vivo Lens Dosimetry in a Case of En Face Electron Adjuvant Radiotherapy for Cutaneous Nasal Bridge Basal Cell Carcinoma: A Case Report

"Radiation therapy represents one of the main treatment modalities for basal cell carcinoma (BCC), the most common type of skin cancer. The proximity of organs at risk (OARs) increases the risk of side effects. Treatment planning system (TPS) estimates the absorbed dose, but the real value can be determined only by in vivo dosimetry. We measured the absorbed dose at the lenses’ level in a case who received electron irradiation for a resected BCC with positive microscopic margins, located at the bridge of the nose. The thermoluminescent eye lens dosimeters (TLD) were placed under the lead protections. We compared the measured dose with the values estimated by TPS. The treatment involved delivering 50 Gy in 25 fractions. A Monaco 5.11 Treatment Planning System (TPS) was used to plan treatment with a 9 MeV electron field and a 10x10 cm applicator at a 100 cm Source-to-Skin Distance (SSD). Customized lead layers and circular lead blocks were used for protection. The TPS estimated maximum doses of 5.87 Gy for the left lens, and 2.70 Gy for the right lens, respectively. After measuring the doses for the first three fractions by TLD, we calculated that maximum dose for the left lens would get to 0.55 Gy, and to 0.30 Gy for the right lens. In this case report we show that irradiation for a BCC localised at the bridge of the nose is possible with proper shielding and can be safely delivered, without exposing the patient to long- term side effects"

A feasibility randomized controlled trial testing the use of indocyanine green fluorescence image-guidance in liver surgery compared to standard liver surgery alone in reducing microscopic positive tumor margin resection rate with an embedded qualitative study: the I-FIGS study protocol

Abstract Indocyanine green fluorescence image-guidance (I-FIGS) is gaining global popularity in liver surgery for various applications. However, its true clinical value in reducing microscopic positive margins (R1-resection rate) remains uncertain. To address this, a multi-center randomized controlled trial (RCT) comparing I-FIGS with standard liver surgery is needed. However, due to a lack of essential information on potential R1 reduction rate, sample size, methodology, intervention delivery and patient experience, a feasibility RCT protocol has been developed to determine the viability of conducting a full-scale RCT. The aim of the study is to conduct a feasibility RCT (fRCT) with an embedded qualitative study to gather all the necessary information for a full-scale RCT. Adult patients undergoing elective liver surgery for colorectal liver metastasis (CRLMs), hepatocellular carcinoma (HCC) or peripheral cholangiocarcinoma will be eligible for the study. Forty patients will be randomly assigned to either the control group (standard liver surgery) or the intervention group (standard liver surgery + I-FIGS). Patients in the I-FIGS group will receive intravenous injection of 0.03–0.05 mg/kg indocyanine green (ICG) dye 2–4 hours before the surgery. Data will be collected on demographics, screening, recruitment and retention rates, adherence to study methods, intraoperative details, postoperative histology, and experiences of both surgeons and patients. Interviews will be conducted with selected patients and surgeons to explore their experiences with the intervention. The protocol has been approved by the West-Midlands-Solihull Research Ethics Committee and registered with ClinicalTrials.gov (NCT05616039). The results will be disseminated through academic publications, congresses, newsletters and other platforms.

43843 Risk factors for terminating Mohs micrographic surgery with positive microscopic tumor margins

43843 Risk factors for terminating Mohs micrographic surgery with positive microscopic tumor margins

Epithelial-Myoepithelial Carcinoma of the Nasal Cavity: A Case Report.

Epithelial-myoepithelial carcinoma is an extremely rare tumor of the nasal cavity. We present a case involving a 67-year-old female with symptoms of nasal obstruction and recurrent epistaxis. An investigation with endoscopy and CT was performed. The patient underwent endoscopic surgical resection. Microscopic positive margins were present after extensive resection. The patient underwent radiotherapy utilizing proton therapy and has been disease free for 6 months at follow-up.

The First Cold Atmospheric Plasma Phase I Clinical Trial for the Treatment of Advanced Solid Tumors: A Novel Treatment Arm for Cancer.

Local regional recurrence (LRR) remains the primary cause of treatment failure in solid tumors despite advancements in cancer therapies. Canady Helios Cold Plasma (CHCP) is a novel Cold Atmospheric Plasma device that generates an Electromagnetic Field and Reactive Oxygen and Nitrogen Species to induce cancer cell death. In the first FDA-approved Phase I trial (March 2020-April 2021), 20 patients with stage IV or recurrent solid tumors underwent surgical resection combined with intra-operative CHCP treatment. Safety was the primary endpoint; secondary endpoints were non-LRR, survival, cancer cell death, and the preservation of surrounding healthy tissue. CHCP did not impact intraoperative physiological data (p > 0.05) or cause any related adverse events. Overall response rates at 26 months for R0 and R0 with microscopic positive margin (R0-MPM) patients were 69% (95% CI, 19-40%) and 100% (95% CI, 100-100.0%), respectively. Survival rates for R0 (n = 7), R0-MPM (n = 5), R1 (n = 6), and R2 (n = 2) patients at 28 months were 86%, 40%, 67%, and 0%, respectively. The cumulative overall survival rate was 24% at 31 months (n = 20, 95% CI, 5.3-100.0). CHCP treatment combined with surgery is safe, selective towards cancer, and demonstrates exceptional LRR control in R0 and R0-MPM patients. (Clinical Trials identifier: NCT04267575).

Refining Target Volume Coverage After Parotidectomy for Cutaneous Squamous Cell Carcinoma: Omission of the Cervical Neck From the Radiation Field

Refining Target Volume Coverage After Parotidectomy for Cutaneous Squamous Cell Carcinoma: Omission of the Cervical Neck From the Radiation Field