Postoperative Intensity-modulated Radiotherapy Research Articles

Implementation of intensity-modulated radiotherapy for head and neck cancers in routine practice

PurposeTo report on patterns of relapse following implementation of intensity-modulated radiotherapy and subsequent changes in practice in a tertiary care centre. Patients and methodsBetween 2008 and 2011, 188 consecutive patients (mean age 59 years old) received intensity-modulated radiotherapies with curative intent for squamous cell carcinomas of the oral cavity (17.5%), oropharynx (43%), hypopharynx (21%), larynx (14%), sinonasal cavities (6%), nasopharynx (1.5%) at the university hospital of Besançon. There were stage I and II 9%, III 24.5%, IV 66.5%. One hundred and thirty-eight underwent exclusive intensity-modulated radiotherapy, 50 underwent postoperative intensity-modulated radiotherapy, 174 had concurrent chemotherapy, 57 had induction chemotherapy. Dynamic intensity-modulated radiotherapy with static fields was performed for all patients using sequential irradiation in 174 patients and simultaneous integrated boost irradiation in 14 patients. ResultsWith a median follow-up was 27.5 months, there was 79% of locoregional failures occurred in the 95% isodose. Two-year overall survival, disease-free, local failure-free and locoregional failure-free survival rates were73%, 60%, 79% and 72%, respectively. Prognostic factors for disease-free survival were stage (IV vs. I–III) with a relative risk of 1.7 [1.1–2.8] (P=0.02) and T stage with 1.6 [1.04–2.5] (P=0.03). ConclusionThe current series showed similar patterns of failure as in other tertiary care centres. We did not identify intensity-modulated radiotherapy specific relapse risks.

Radiotherapy Characteristics and Outcomes for Head and Neck Carcinoma of Unknown Primary vs T1 Base-of-Tongue Carcinoma

Transoral robotic surgery- or transoral laser microsurgery-assisted lingual tonsillectomy may improve the identification rate of hidden base-of-tongue (BOT) carcinoma presenting as head or neck carcinoma of unknown primary (CUP) site. To evaluate the potential impact of lingual tonsillectomy in CUP site by comparing differences in radiotherapy volumes, dosimetry, and clinical outcomes for CUP site and T1-category BOT carcinoma. Retrospective study of 115 patients treated at a tertiary cancer center between January 1, 2005, and December 31, 2013, that included patients with BOT carcinoma (category T1N1-3M0) and CUP site (category T0N1-3M0) with known p16 status. Fifty-four patients with T1-category BOT carcinoma (50 [92.6%] p16-positive) were treated with definitive intensity-modulated radiotherapy (IMRT), including 34 (63%) who received concurrent chemotherapy. Sixty-one patients with CUP site (38 [62.3%] p16-positive) received definitive (42 [68.9%]) or postoperative (19 [31.1%]) IMRT, including 22 (36%) who received concurrent chemotherapy. Definitive or postoperative IMRT, with or without concurrent chemotherapy. Characteristics of mucosal clinical target volume (CTV-T), nodal CTV, and organ-at-risk dosimetry; local, regional, and distant control; cause-specific and overall survival; and Radiation Therapy Oncology Group grade 3 or higher late toxic effects. Of 115 participants, 104 (90.4%) were male; mean (SD) age was 59 (10) years. High-dose CTV-T was prescribed in all 54 patients with BOT carcinoma and 23 (37.7%) with CUP site (effect size [Δ], 62%; 95% CI, 50%-74%). Low-dose CTV-T included mucosal pharyngeal sites outside the oropharynx in no patients with BOT carcinoma and 26 (42.6%) (95% CI, 30%-54%) with CUP site, with greater low-dose CTV-T volume in CUP site than BOT carcinoma (113 vs 84 cm3; Δ, 30 cm3; 95% CI, 10-49 cm3). Bilateral neck irradiation was used in 53 of 54 patients (98.1%) with BOT carcinoma and 46 of 61 (75.4%) with CUP site (Δ, 23%; 95% CI, 12% to 34%). Patients with BOT carcinoma received a higher maximum dose to the mandible (71 vs 67.2 Gy; Δ, 3.8 Gy; 95% CI, 1.6 to 6 Gy), with a nonsignificantly higher maximum dose (66.1 vs 62.8 Gy; 3.2 Gy; 95% CI, -0.1 to 6.5 Gy) and lower mean dose to the larynx (43.8 vs 47.1 Gy; 3.3 Gy; 95% CI, -0.3 to 6.9 Gy). There were no significant differences in local control, regional control, distant control, cause-specific survival, and overall survival between the BOT carcinoma and CUP site groups stratified by p16 status. Grade 3 Radiation Therapy Oncology Group late toxic effects occurred in 2 patients (3.3%) with CUP site (both neck fibrosis) and 5 (9.3%) with BOT carcinoma (2 neck fibrosis, 2 osteoradionecrosis, and 1 dysphagia). Intensity-modulated radiotherapy for CUP site or T1-category BOT carcinoma had similar clinical outcomes. Identifying hidden BOT primary carcinoma with novel approaches (eg, transoral robotic surgery and transoral laser microsurgery) may lead to changes in the radiotherapy target volume and dose prescription. Studies are needed to investigate the effect of these differences on quality of life and functional outcomes.

Updated 4-Year Results for NRG Oncology/RTOG 0921: A Phase 2 Study of Postoperative Intensity Modulated Radiation Therapy With Concurrent Cisplatin and Bevacizumab Followed by Carboplatin and Paclitaxel for Patients With Endometrial Cancer

Updated 4-Year Results for NRG Oncology/RTOG 0921: A Phase 2 Study of Postoperative Intensity Modulated Radiation Therapy With Concurrent Cisplatin and Bevacizumab Followed by Carboplatin and Paclitaxel for Patients With Endometrial Cancer

Patterns of failure after postoperative intensity-modulated radiotherapy for locally advanced and recurrent head and neck cancer.

To evaluate the feasibility of postoperative intensity-modulated radiotherapyfor head and neck cancer by investigating the patterns of failure after this therapy. A retrospective chart review was performed. Between March 2006 and December 2013, 122 consecutive patients with head and neck squamous cell carcinoma were treated by surgery followed by postoperative intensity-modulated radiotherapy. In regard to the site of the primary tumor, 59 (48%) patients had cancer of the oral cavity, 31 (26%) patients had cancer of the hypopharynx, 14 (11%) patients had cancer of the oropharynx, 10 (8%) patients had cancer of the larynx and 8 (7%) patients had cancer of unknown primary. The median follow-up period of the surviving patients was 54 months (range, 25-115). Concurrent chemotherapy was administered in 76 patients (62%). The median prescribed radiation dose was 66 Gy. The 3-year overall survival, progression-free survival, distant metastasis free survival and loco-regional control rates were 59%, 48%, 52.4% and 71%, respectively. Of the 122 patients, 32 developed loco-regional recurrence as the initial recurrence, including in-field recurrence in 26 patients, marginal recurrence in five patients and out-field recurrence in seven patients. Of the five patients with marginal recurrence, four have had two or more surgeries before the intensity-modulated radiotherapy and three had oral cavity cancer. Severe adverse events were not frequent, occurring at a frequency of <5%, except for mucositis. No severe toxicities associated with the flap reconstruction were observed either. Postoperative intensity-modulated radiotherapy appears to be effective and feasible for patients with head and neck squamous cell carcinoma.

Clinical outcome of intensity modulated radiotherapy for carcinoma showing thymus-like differentiation.

PurposeTo evaluate the efficacy and toxicity of adjuvant intensity-modulated radiotherapy (IMRT) after surgery for carcinoma showing thymus-like differentiation (CASTLE).MethodsBetween September 2008 and June 2015, 14 CASTLE patients were retrospectively enrolled. The clinical features, treatment procedure and clinical outcomes were reviewed. All patients received postoperative IMRT. The radiation doses ranged from 56Gy/28 fractions to 66Gy/33 fractions. Treatment-related toxicities were graded by National Cancer Institute Common Toxicity Criteria (NCI-CTC) version 3.0.ResultsAfter a median follow-up period of 42 months, only one patient suffered local recurrence and distant metastasis. The most frequently seen acute toxicities were mucositis and dermatitis (grade 1-2). No grade 3-4 toxicities were observed.ConclusionsAlthough based upon a small series of consecutively treated patients, our study showed that adjuvant IMRT provides satisfactory local-regional control for CASTLE, with acceptable toxicities. Further studies are still warranted to clarify our findings.

Impact of postoperative intensity-modulated radiation therapy (IMRT) on the rate of bowel obstruction in gynecologic malignancy

ObjectiveThe purpose was to determine the potential impact of IMRT on the rate of bowel obstruction (BO), in patients with gynecologic malignancies undergoing postoperative pelvic RT. MethodsWe performed a retrospective review of all patients with endometrial or cervical cancer who received postoperative pelvic RT at our institution from 2000 to 2012. Patients who received definitive or palliative RT, or those with BO due to disease progression, were excluded. Standard two-sided statistical tests were used to evaluate for associated risk factors. Kaplan-Meier, Log rank and Cox proportional hazards regression analysis tests were performed for actuarial analysis. ResultsA total of 224 patients were identified, 120 (54%) received postoperative pelvic IMRT and 104 (46%) 3-dimentional (3-D) RT. Median follow-up time was 67months. BO was grade 1 (asymptomatic) in 2/228 (0.9%), grade 2 (conservative management) in 4 (1.8%), and grade 3≥ in 4 (1.8%). Overall, the 5-year actuarial rate of BO was 4.8%. The 5-year rate of BO in the IMRT group was 0.9% compared to 9.3% for 3-D RT (p=0.006). Patients with BMI≥30kg/m2 were less likely to develop BO (2.6% vs. 8.3; p=0.03). On multivariate analysis, only IMRT retained its significance as an independent predictor of less BO (p=0.022). ConclusionsThe use of postoperative IMRT for cervical and endometrial cancer was associated with significant reduction in the rate of bowel obstruction. This difference maintained its statistical significance on multivariate analysis. Such finding if confirmed by others will help further solidify the benefit of IMRT in gynecologic cancers.

Possible contribution of IMRT in postoperative radiochemotherapy for rectal cancer: analysis on 1798 patients by prediction model.

The evidence for adjuvant therapy in locally advanced rectal cancer after TME surgery is sparse. The aim of this study was to identify predicting factors of overall survival (OS) in these patients and combine them into a nomogram for individualized treatment. 1798 patients with pathologically staged II/III rectal adenocarcinoma treated by radical TME surgery from a single center's database were reviewed. The nomogram was derived by Cox proportional hazards regression. Its performance was assessed by concordance index and calibration curve in internal validation with bootstrapping. Pooled Cox model analysis identified age, sex, grade of histology, pathological T and N stage, residual tumor, concurrent radiochemotherapy (RTCT), adjuvant chemotherapy cycles (CT), radiotherapy (RT) unexpected interruption days and intensity-modulated radiation therapy (IMRT) as significant covariates for 5-year OS (P<0.05). Postoperative RTCT, CT and IMRT all improved OS. The proposed model can predict 5-year OS with a C-index of 0.7105. IMRT significantly benefited OS in multivariate analysis (p=0.0441).In conclusion, our nomogram can predict 5-year OS after TME surgery for locally advanced rectal cancer with simple and effective advantage. This model may provide not only baseline OS estimate but also a tool for candidates selecting of adjuvant treatment in prospective studies.

Postoperative radiotherapy combined with concurrent paclitaxel-nedaplatin chemotherapy for esophageal cancer: a preliminary study

Objective To investigate the safety and preliminary effect of postoperative intensity-modulated radiotherapy (IMRT) combined with concurrent weekly paclitaxel-nedaplatin chemotherapy for patients with esophageal squamous cell carcinoma. Methods A total of 52 patients who were treated from 2010 to 2013 were enrolled. The clinical target volume of IMRT included tumor beds and corresponding lymphatic drainage regions at high risk, and the total radiotherapy dose was 50-60 Gy, 2.0 Gy/fraction, 5 fractions per week. The concurrent chemotherapy consisted of nedaplatin 25 mg/m2 on D1 and paclitaxel 45-50 mg/m2 on D1 and was repeated every week during radiotherapy. Common Terminology Criteria for Adverse Events 4.0 was used to evaluate adverse events, and the Kaplan-Meier method was used for survival analysis. Results All the patients had good tolerance to the treatment, and 51 patients (98%) completed radiotherapy according to the scheduled regimen. The median number of chemotherapy cycles was 4, and 42 patients (81%) completed ≥3 cycles of chemotherapy. Most adverse events were of grade 1-2, and grade 3 adverse events were leucopenia (29%), radiation esophagitis (10%), and anastomotic stenosis (4%). One patient (2%) experienced grade 5 gastroesophageal bleeding. Of all the patients, the median survival time was 38.7 months, and the 1-, 2-, 3-, and 4-year overall survival rates were 83%, 64%, 51%, and 38%, respectively. The overall recurrence rate was 46.2%, and the locoregional recurrence rate and distant metastasis rate were 15% and 37%, respectively. Conclusions Postoperative IMRT combined with concurrent weekly paclitaxel-nedaplatin chemotherapy for patients with esophageal squamous cell carcinoma is safe and effective, and large-scale prospective randomized studies are needed. Key words: Esophageal neoplasms/radiochemotherapy; Radiochemotherapy, concurrent; Efficacy; Security

Should we customize PTV expansions for BMI? Daily cone beam computerized tomography to assess organ motion in postoperative endometrial and cervical cancer patients

AimA single-institution review assessing patient characteristics contributing to daily organ motion in postoperative endometrial and cervical cancer patients treated with intensity-modulated radiotherapy (IMRT). BackgroundThe Radiation Therapy Oncology Group has established consensus guidelines for postoperative pelvic IMRT, recommending a 7mm margin on all three axes of the target volume. Materials and methodsDaily shifts on 457 radiation setups for 18 patients were recorded in the x axis (lateral), y axis (superior–inferior) and z axis (anterior–posterior); daily positions of the planning tumor volume were referenced with the initial planning scan to quantify variations. ResultsOf the 457 sessions, 85 (18.6%) had plan shifts of at least 7mm in one of the three dimensions. For obese patients (body mass index [BMI]≥30), 75/306 (24.5%) sessions had plan shifts ≥7mm. Odds of having a shift ≥7mm in any direction was greater for obese patients under both univariate (OR 4.227, 95% CI 1.235–14.466, p=0.021) and multivariate (OR 5.000, 95% CI 1.341–18.646, p=0.016) analyses (MVA). Under MVA, having a BMI≥30 was associated with increased odds of shifts in the anterior–posterior (1.173mm, 95% CI 0.281–2.065, p=0.001) and lateral (2.074mm, 95% CI 1.284–2.864, p<0.000) directions but not in the superior–inferior axis (0.298mm, 95% CI −0.880 to 1.475, p=0.619) exceeding 7mm. ConclusionsBased on these findings, the standard planned tumor volume expansion of 7mm is less likely to account for daily treatment changes in obese patients.

Proposed definition of the vaginal cuff and paracolpium clinical target volume in postoperative uterine cervical cancer

PurposeThe aim of this study was to develop an appropriate definition for vaginal cuff and paracolpium clinical target volume (CTV) for postoperative intensity modulated radiation therapy in patients with uterine cervical cancer. Methods and materialsA working subgroup was organized within the Radiation Therapy Study Group of the Japan Clinical Oncology Group to develop a definition for the postoperative vaginal cuff and paracolpium CTV in December 2013. The group consisted of 5 radiation oncologists who specialized in gynecologic oncology and a gynecologic oncologist. A comprehensive literature review that included anatomy, surgery, and imaging fields was performed and was followed by multiple discreet face-to-face discussions and e-mail messages before a final consensus was reached. ResultsDefinitions for the landmark structures in all directions that demarcate the vaginal cuff and paracolpium CTV were decided by consensus agreement of the working group. A table was created that showed boundary structures of the vaginal cuff and paracolpium CTV in each direction. ConclusionsA definition of the postoperative cervical cancer vaginal cuff and paracolpium CTV was developed. It is expected that this definition guideline will serve as a template for future radiation therapy clinical trial protocols, especially protocols involving intensity modulated radiation therapy.

The Next Generation of Mesothelioma Surgeons Roundtable Discussion

DR. PASS: The topic for this roundtable discussions for Seminars in Thoracic and Cardiovascular Surgery is going to be surgery for mesothelioma. Our participants are Joe Friedberg, University of Maryland; Andrea Wolf, Icahn School of Medicine at Mount Sinai; David Rice, MD Anderson Cancer Center; and Wickii Vigneswaran, Loyola University Health System. All 4 of these surgeons were trained and are presently at high volume mesothelioma centers. Drs. Wolf and Friedberg were trained by Dr. Sugarbaker. Dr. Vigneswaran was trained at Mayo, and performed a large volume of surgical cases at the University of Chicago where he has a lot of cases that are both surgical as well as medical. Dr. Rice practices at MD Anderson and was one of the innovators of postoperative intensity-modulated radiotherapy (IMRT).

Bladder dose-volume parameters are associated with urinary incontinence after postoperative intensity modulated radiation therapy for prostate cancer

PurposeUrinary incontinence is a potential side effect of prostatectomy and intensity modulated radiation therapy (IMRT) for prostate cancer. There are limited data on dosimetric parameters that may predict for poor continence recovery in men who receive postoperative IMRT. Methods and materialsEighty-seven men with nonmetastatic prostate cancer who underwent prostatectomy followed by adjuvant (13%) or salvage (87%) IMRT were identified. The Expanded Prostate Cancer Index composite questionnaire was prospectively collected at baseline, 6 weeks, and 6, 12, 18, 24, 36, and 48 months post-IMRT. Relevant critical structures were contoured and dose-volume metrics collected. The primary endpoint was urinary continence global score. Longitudinal analysis using a generalized estimating equation model was performed. ResultsThere was no statistically significant change in Expanded Prostate Cancer Index composite urinary continence global scores over time as compared with baseline (all P > .05). In univariate analysis, bladder volume receiving 70 Gy (V70 Gy) and penile bulb V70 Gy were associated with urinary continence (odds ratio, 0.82; P < .05). In a multivariable model that included body mass index, distance between vesicourethral junction and genitourinary diaphragm, time from surgery, use of antihypertensive medications, age, diabetes, and bladder V70 Gy, only bladder V70 Gy (odds ratio, 0.82; P = .03) was associated with outcome. After 2 years, there was a significant difference in global score for those with V70 Gy < 42.27 versus ≥42.27 mL (all P < .05 at 2 and 3 years post-IMRT). ConclusionThere was no significant change in patient-reported urinary continence scores after postprostatectomy IMRT. Bladder V70 Gy was independently associated with a decrease in urinary continence scores. Further evaluation is necessary to optimize quality of life in these men.

An assessment of interfractional bladder, rectum and vagina motion in postoperative cervical cancer based on daily cone-beam computed tomography.

Interfractional variations of the bladder, rectum and vagina may affect the accuracy of postoperative intensity-modulated radiotherapy in patients with cervical cancer. This study aimed to assess the interfractional variations with daily kV cone-beam computed tomography (CBCT). All the patients were instructed to control the filling status of the bladder and rectum. CBCT images were obtained daily after set-up and the bladder, rectum and vagina were contoured on each CBCT scan. All the contours were transferred to the planning CT following image fusion. Interfractional variations in pelvic organs were assessed with CBCT based on two reference lines, which were identified as A (the midsaggital line across the superior border of pubic symphysis) and B (a parallel line 1.5 cm above line A). The mean volume (range) of the bladder and rectum was 156.5 (1.7-626.5) and 48.2 (11.3-139.7) ml, respectively. The uniform planning target volume (PTV) margin of 10 mm failed to encompass the vagina in 17.3 and 18.1% of the fractions on lines A and B, respectively. The motion of the vagina (standard deviation) was 0.3 (0.3) and 0.1 (0.5) cm on lines A and B, respectively. The anteroposterior dimension and position of the vagina were significantly affected by the filling status of the bladder (P<0.05), but not by that of the rectum. Although instructions were given, the interfractional variations of the vagina and other pelvic organs were significant, which may exceed the uniform PTV margin; therefore, more effective methods to decrease these variations should be investigated.

Long term results of postoperative Intensity-Modulated Radiation Therapy (IMRT) in the treatment of Squamous Cell Carcinoma (SCC) located in the oropharynx or oral cavity.

BackgroundTo report our long-term results with postoperative intensity-modulated radiation therapy (IMRT) in patients suffering from squamous-cell carcinoma (SCC) of the oral cavity or oropharynx.MethodsSeventy five patients were retrospectively analyzed. Median age was 58 years and 84 % were male. 76 % of the primaries were located in the oropharynx. Surgery resulted in negative margins (R0) in 64 % of the patients while 36 % suffered from positive margins (R1). Postoperative stages were as follows: stage1:4 %, stage2:9 %, stage3:17 %, stage4a:69 % with positive nodes in 84 %. Perineural invasion (Pn+) and extracapsular extension (ECE) were present in 7 % and 29 %, respectively. All patients received IMRT using the step-and-shoot approach with a simultaneously integrated boost (SIB) in 84 %. Concurrent systemic therapy was applied to 53 patients, mainly cisplatin weekly.ResultsMedian follow-up was 55 months (5–150). 13 patients showed locoregional failures (4 isolated local, 4 isolated neck, 5 combined) transferring into 5-year-LRC rates of 85 %. Number of positive lymph nodes (n > 2) and presence of ECE were significantly associated with decreased LRC in univariate analysis, but only the number of nodes remained significant in multivariate analysis. Overall treatment failures occurred in 20 patients (9 locoregional only, 7 distant only, 4 combined), transferring into 3-and 5-year-FFTF rates of 77 % and 75 %, respectively. The 3-and 5-year-OS rates were 80 % and 72 %, respectively. High clinical stage, high N stage, number of positive nodes (n > 2), ECE and Pn1 were significantly associated with worse FFTF and OS in univariate analysis, but only number of nodes remained significant for FFTF in multivariate analysis. Maximum acute toxicity was grade 3 in 64 % and grade 4 in 1 %, mainly hematological or mucositis/dysphagia. Maximum late toxicity was grade 3 in 23 % of the patients, mainly long-term tube feeding dependency.ConclusionPostoperative IMRT achieved excellent LRC and good OS with acceptable acute and low late toxicity rates. The number of positive nodes (n > 2) was a strong prognostic factor for all endpoints in univariate and the only significant factor for LRC and FFTF in multivariate analysis. Patients with feeding tubes due to postoperative complications had an increased risk for long-term feeding tube dependency.

Analysis of efficacy and prognostic factors of postoperative intensity-modulated radiotherapy with or without chemotherapy in rectal cancer

Objective To explore the efficacy and prognostic factors of postoperative intensity-modulated radiotherapy (IMRT) with or without chemotherapy in rectal cancer. Methods A retrospective analysis was performed on the clinical data of 218 patients with rectal cancer, who underwent postoperative IMRT in our hospital from January 2009 to December 2013.The Kaplan-Meier method was used to calculate survival rate; the log-rank test was used for survival difference analysis and univariate prognostic analysis; the Cox regression model was used for multivariate prognostic analysis. Results The follow-up rate was 97.7%. The 1-and 3-year overall survival rates were 90.8% and 75.2%, respectively, the 1-and 3-year disease-free survival rates were 85.3% and 70.5%, respectively, and the 1-and 3-year locoregional recurrence-free survival rates were 96.7% and 88.1%, respectively. The incidence of grade 3-4 acute adverse reactions was 28.4%, mainly manifested as leukopenia (13.8%) and diarrhea (11.0%). Univariate prognostic analysis showed that preoperative carcinoembryonic antigen (CEA) and CA199 levels, maximum tumor diameter, tumor location, degree of differentiation, depth of tumor invasion, number of lymph node metastases, TNM stage, perineural invasion, surgical procedure, total mesorectal excision, preoperative bowel obstruction, and preoperative anemia were the predictors of survival (P=0.006, 0.000, 0.000, 0.017, 0.000, 0.016, 0.000, 0.011, 0.001, 0.006, 0.037 and 0.010). Multivariate prognostic analysis showed that preoperative CEA level, tumor location, TNM stage, preoperative bowel obstruction, and preoperative anemia were the predictors of survival (P=0.000, 0.000, 0.000, 0.001 and 0.001). Conclusions Postoperative IMRT with or without chemotherapy is an effective method for rectal cancer with mild adverse reactions and high compliance. Preoperative CEA level, tumor position, TNM stage, preoperative bowel obstruction, and preoperative anemia are independent prognostic factors for the overall survival. Key words: Rectal neoplasms/radiochemotherapy; Radiotherapy, intensity-modulated radiotherapy; Prognosis

Impact of Postoperative Intensity Modulated Radiation Therapy (IMRT) on the Rate of Bowel Obstruction in Gynecologic Malignancy

Impact of Postoperative Intensity Modulated Radiation Therapy (IMRT) on the Rate of Bowel Obstruction in Gynecologic Malignancy

Impact of Surgical Margins on Outcomes in Oral Cavity Squamous Cell Carcinoma Following Postoperative Intensity Modulated Radiation Therapy

Impact of Surgical Margins on Outcomes in Oral Cavity Squamous Cell Carcinoma Following Postoperative Intensity Modulated Radiation Therapy

Outcomes of Head and Neck Adenoid Cystic Carcinoma Treated Definitively With Surgery and Postoperative Intensity Modulated Radiation Therapy

Outcomes of Head and Neck Adenoid Cystic Carcinoma Treated Definitively With Surgery and Postoperative Intensity Modulated Radiation Therapy

Analysis of Efficacy and Prognostic Factors of Postoperative Intensity Modulated Radiation Therapy in Rectal Cancer

Analysis of Efficacy and Prognostic Factors of Postoperative Intensity Modulated Radiation Therapy in Rectal Cancer

Patterns of Relapse in Patients With Endometrial Cancer Treated With Postoperative Intensity Modulated Radiation Therapy (IMRT)

Patterns of Relapse in Patients With Endometrial Cancer Treated With Postoperative Intensity Modulated Radiation Therapy (IMRT)