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Purpose@#This study aims to determine the association between pre- and postoperative radiotherapy (PORT) circulating tumor DNA (ctDNA) dynamics and oncological outcomes in patients with residual triple-negative breast cancer who underwent surgery after neoadjuvant chemotherapy (NAC). @*Materials and Methods@#Between March 2019 and July 2020, 11 nonmetastatic patients with residual disease who underwent surgery after NAC were prospectively enrolled. In each patient, tumor specimens obtained during surgery and blood samples collected at three time points during PORT (T0: pre-PORT, T1: 3 weeks after PORT, T2: 1 month after PORT) were sequenced, targeting 38 cancer-related genes. Disease-free survival (DFS) was evaluated and the association between DFS and ctDNA dynamics was analyzed. @*Results@#At T0, ctDNA was detected in three (27.2%) patients. The ctDNA dynamics were as follows: two showed a decreasing ctDNA variant allele frequency (VAF) and reached zero VAF at T2, while one patient exhibited an increasing VAF during PORT and maintained an elevated VAF at T2. After a median follow-up of 48 months, two patients experienced distant metastasis without any locoregional failures. All failures occurred in patients with ctDNA positivity at T0 and a decreased VAF after PORT. The 4-year DFS rates according to the T0 ctDNA status were 67% (positive ctDNA) and 100% (negative ctDNA) (p=0.032). @*Conclusion@#More than a quarter of the patients with residual disease after post-NAC surgery exhibited pre-PORT ctDNA positivity, and ctDNA positivity was associated with poor DFS. For patients with pre-PORT ctDNA positivity, the administration of a more effective systemic treatment should be considered.
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Purpose@#Hypofractionated radiotherapy (HypoRT) has recently been implemented in patients with glioblastoma (GBM) receiving concurrent temozolomide. Lymphopenia during treatment (LDT) is considered an important prognostic factor of clinical outcomes for GBM. We aimed to investigate the outcomes of HypoRT. @*Materials and Methods@#Among 223 patients with GBM, 145 and 78 were treated with conventionally fractionated RT (ConvRT, 60 Gy in 30 fractions) and HypoRT (58.5 Gy in 25 fractions), respectively. To balance characteristics between the two groups, propensity score matching (PSM) was performed. @*Results@#Patients in the HypoRT group were older and had smaller tumors than those in the ConvRT group (p0.05). Multivariable analysis before PSM revealed that ≥grade 2 LDT at 6 months was associated with inferior outcomes. Subsequent analysis demonstrated that HypoRT significantly reduced the rate of ≥grade 2 LDT at 6 months post-RT before and after PSM. @*Conclusion@#HypoRT with 58.5 Gy in 25 fractions could provide comparable oncologic outcomes and significantly reduce the ALC changes. In addition, HypoRT decreased the LDT. Further investigation should be warranted to suggest the significance of reduced LDT through HypoRT affecting survival outcomes.
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Purpose@#Data on subsequent arm lymphedema (SAL) after salvage treatment for locoregional recurrence (LRR) of breast cancer are limited. We conducted a study to evaluate the risk of SAL in patients with LRR. @*Methods@#We reviewed the data of patients with breast cancer who had LRR and were initially diagnosed between January 2003 and December 2017. Among the 214 patients who received curative salvage treatment, most had local (n = 125, 57.9%), followed by regional (n = 73, 34.1%), and locoregional (n = 16, 7.9%) recurrences. A competing risk analysis considering the factors of death and a second LRR were performed to exclude potential malignant lymphedema. We used the Fine-Gray subdistribution hazards model to estimate the hazard ratio (HR) for comparing the risk of SAL. @*Results@#With a median follow-up duration of 41.4 months (interquartile range, 25.6–65.1), 51 patients (23.8%) experienced SAL with a median interval of 9.9 months after treatment.The two-year cumulative incidence of SAL was 12.7%. Among the 18 patients with initial lymphedema, nine (50.0%) developed SAL. Multivariate analysis revealed that a history of lymphedema (HR, 4.61; p < 0.001) and taxane-based salvage chemotherapy (HR, 2.38; p = 0.009) were significantly associated with SAL development. @*Conclusion@#Salvage treatment for LRR-induced SAL was performed in 24% of the patients.A history of initial lymphedema and salvage taxane-based chemotherapy increases the risk of developing SAL. Therefore, close surveillance for the incidence of SAL is required in patients opting for salvage treatment for LRR.
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Background@#/Aim: Patients with large (>5 cm) hepatocellular carcinoma (HCC) have limited treatment options, thus necessitating the identification of prognostic factors and the development of predictive tools. This study aimed to identify prognostic factors and to construct a nomogram to predict survival outcomes in patients with large HCC. @*Methods@#A cohort of 438 patients, who were diagnosed with large HCC at a tertiary hospital between 2015 and 2018, was analyzed. Cox proportional hazards models were used to identify key prognosticators of overall survival (OS), and an independent set of prognostic factors was used to develop a nomogram. The discrimination and calibration abilities of the nomogram were assessed and internal validation was performed using cross-validation and bootstrapping methods. @*Results@#During a median follow-up of 9.3 months, the median OS was 9.9 months, and the 1-year OS rate was 43.9%. Multivariable Cox regression analysis revealed that performance status, modified albumin-bilirubin grade, tumor size, extent of portal vein tumor thrombosis, and initial treatment significantly affected OS. The newly developed nomogram incorporating these variables demonstrated favorable accuracy (Harrell’s concordance index, 0.807). @*Conclusions@#The newly developed nomogram facilitated the estimation of individual survival outcomes in patients with large HCC, providing an acceptable level of accuracy.
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Historical conventional fractionated radiation therapy (RT) for breast cancer consisted of 1.8–2.0 Gy per fraction with a total dose of 45–60 Gy over 5–7 weeks. Based on radiobiological characteristics, a low α/β is suspected of breast cancer resulting in sensitivity to higher dose per fraction (2.5–3.0 Gy). Over the past 10 years, multiple clinical trials support the application of shorter treatment regimen with hypofractionated RT (HypoRT). Recently, ultra-HypoRT with 5 fractions showed favorable outcomes. Although the safety and efficacy of HypoRT has been supported by high-quality randomized trials, there are still some worries and doubts around HypoRT from radiation oncologists. However, the radiation oncology community have now reached an important timepoint for adopting HypoRT during the COVID-19 pandemic. The aim of this review is to provide an overview of HypoRT in breast cancer based on prospective randomized trials and discuss the special consideration regarding HypoRT.
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Optic pathway glioma (OPG) is a rare tumor located in optic nerve, optic tract, or optic chiasm. Treatment options for OPG include surgery, radiation therapy (RT), and chemotherapy. Although RT may provide favorable long-term outcomes in manner of either adjuvant or salvage aim, chemotherapy-first approach is increasingly performed due to possible late effects of RT. Proton beam RT may allow normal tissue sparing of radiation exposure compared to conventional X-ray treatment. Therefore, proton beam RT is expected to reduce complications from RT. This review discusses the recent updates on oncologic outcomes of OPG, late toxicities following RT, and compares the outcomes between X-ray treatment and proton beam RT.
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Purpose@#Larynx-preserving surgery (LPS) have recently gained popularity and achieved comparable oncologic outcomes to conventional radical surgery for localized hypopharyngeal cancer (HPC). In the current study, the role of LPS has been assessed thoroughly in comparison with upfront radiation therapy (RT). @*Materials and Methods@#We retrospectively reviewed 185 candidates for LPS with cT1-2 disease; 59 patients underwent upfront LPS while 126 patients received upfront RT, respectively. Oncological and functional outcomes were investigated and compared. @*Results@#Following LPS, safe margin (≥ 5 mm) was achieved in 37.3% of patients. Overall, better clinical outcomes at 5 years were achieved following upfront LPS than those following upfront RT: overall survival (OS) (72.7% vs. 59.0%, p=0.045), disease-free survival (DFS) (59.8% vs. 45.0%, p=0.039), and functional laryngeal preservation (100% vs. 89.7%, p=0.010). Although similar outcomes were observed in patients with cT1 disease, better 5-year DFS was achieved following upfront LPS in patients with cT2 disease (57.0% vs. 36.4%, p=0.023) by virtue of better local control. Despite frequent cN2-3 disease in upfront LPS group, comparable outcomes were observed between upfront RT and LPS group. However, multivariable analyses revealed that performance status and double primary cancer diagnosed within 6 months of HPC diagnosis affected OS significantly, while treatment modality per se did not. @*Conclusion@#Although upfront LPS could provide better local control than upfront RT in patients with cT2 disease, overall outcomes were comparable following either modality. Treatment selection of larynx-preserving approach for HPC should be individualized based on tumor and patient factors.
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Purpose@#The optimal timing for radiotherapy (RT) after incomplete transarterial chemoembolization (TACE) remains unclear. This study investigated the optimal timing to initiate RT after incomplete TACE in patients with Barcelona Clinic Liver Cancer stage B hepatocellular carcinoma. @*Materials and Methods@#This study included 116 lesions in 104 patients who were treated with RT after TACE between 2001 and 2016. The time interval between the last TACE session and RT initiation was retrospectively analyzed. The optimal cut-off time interval that maximized the difference in local failure-free rates (LFFRs) was determined using maximally selected rank statistics. @*Results@#The median time interval was 26 days (range: 2–165 days). At a median follow-up of 18 months (range: 3–160 months), the median overall survival was 18 months. The optimal cut-off time interval appeared to be 5 weeks; using this cut-off, 65 and 39 patients were classified into early and late RT groups, respectively. Early RT group had a significantly poorer Child-Pugh class and higher alpha-fetoprotein levels compared to late RT group. Other characteristics, including tumor size (7 cm vs. 6 cm; p=0.144), were not significantly different between the groups. The 1-year LFFR was significantly higher in the early RT group than in the late RT group (94.6% vs. 70.8%; p=0.005). On multivariate analysis, early RT was identified as an independent predictor of favorable local failure-free survival (hazard ratio: 3.30, 95% confidence interval: 1.50–7.29; p=0.003). @*Conclusion@#The optimal timing for administering RT after incomplete TACE is within 5 weeks. Early administration of RT is associated with better local control.
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Purpose@#This study aimed to identify the prognostic value of early metabolic response assessed using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) during radiation therapy (RT) for cervical cancer. @*Materials and Methods@#We identified 116 patients treated with definitive RT, including FDG-PET/CT–guided intracavitary brachytherapy, between 2009 and 2018. We calculated parameters including maximum (SUVmax) and mean standardized uptake values (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for baseline FDG-PET/CT (PETbase) and image-guided brachytherapy planning FDG-PET/CT (PETIGBT). Multivariable analyses of disease-free survival (DFS) and overall survival (OS) were performed. @*Results@#We observed a time-dependent decrease in PET parameters between PETbase and PETIGBT; ΔSUVmax, ΔSUVmean, ΔMTV, and ΔTLG were 65%, 61%, 78%, and 93%, respectively. With a median follow-up of 59.5 months, the 5-year DFS and OS rates were 66% and 79%, respectively. Multivariable analysis demonstrated that ΔSUVmax ≥ 50% was associated with favorable DFS (hazard ratio [HR], 2.56; 95% confidence interval [CI], 1.14 to 5.77) and OS (HR, 5.14; 95% CI, 1.55 to 17.01). Patients with ΔSUVmax ≥ 50% (n=87) showed better DFS and OS than those with ΔSUVmax 50%, can help improve survival outcome predictions for patients with cervical cancer treated with definitive RT.
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Objective@#The Korean Radiation Oncology Group conducted a nationwide questionnaire survey to evaluate the patterns of clinical practice for patients with cervical cancer receiving definitive radiation therapy (RT) in South Korea. @*Methods@#Practicing radiation oncologists from 93 centers in South Korea were administered a questionnaire survey via e-mail. The survey focused on demographic characteristics, diagnostic evaluation, indications for definitive RT, RT techniques, RT field and dose prescription, lymph node (LN) boost RT, brachytherapy, and chemotherapy. @*Results@#The response rate was 62.4% (58/93 institutions). Of the 2,134 patients treated at the radiation oncology department in 2019, 48.8% underwent definitive RT. The selection of patients for definitive concurrent chemoradiation therapy and RT field, and RT dose prescription varied greatly. The upper border of the pelvis was commonly used as the bony landmark for external beam RT (81%–88% of respondents). Most (96.6%) centers performed LN boost RT with median total doses of 59 Gy and 59.2 Gy for pelvic and retroperitoneal LN, respectively. With 50% of the centers offering brachytherapy, image-guided brachytherapy and volume-based prescription were applied in 48.3% and 37.9%, respectively. Upfront concurrent chemoradiation therapy with varying prescription doses was considered by 60.4% respondents in cases of supraclavicular LN metastasis. @*Conclusion@#Most differences were noted in the indications for treatment, RT field, and prescription dose. This finding can serve as a reference for establishing practical RT guidelines for the management of locally advanced cervical cancer.
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Objective@#Unlike cervical squamous cell carcinoma, there are no consensus criteria for serum tumor markers in cervical adenocarcinoma. This study aimed to identify the prognostic value of preoperative carbohydrate antigen 125 (CA125) levels in cervical adenocarcinoma patients with adverse pathologic features. @*Methods@#A total of 105 patients who underwent radical hysterectomy followed by adjuvant radiotherapy (RT) or concurrent chemoradiation therapy were included. Locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), and overall survival (OS) were evaluated using the Cox proportional hazard regression model. @*Results@#Using a cutoff value of 50 U/mL, 83 and 22 patients had low- and high-CA125, respectively. Patients with high-CA125 had a larger tumor size, more frequent parametrial extension, and more frequent lymph node metastasis than those with low-CA125. During a median follow-up of 59.3 (interquartile range, 32.7–97.8) months, patients with high-CA125 showed inferior 5-year LRFS, DMFS, and OS rates compared to those with low-CA125 (38.5% vs. 70.0%; 37.0% vs. 69.4%; 43.6% vs. 78.1%, respectively, all p<0.05). In multivariable analysis, the high-CA125 remained significant prognostic factor for LRFS, DMFS, and OS (all p<0.05). Furthermore, 12 patients with high-CA125 at recurrence exhibited lower 5-year OS rates than 21 patients with low-CA125 at recurrence (0.0% vs. 51.3%, p=0.003). @*Conclusion@#In this retrospective analysis, the serum CA125 level at diagnosis and recurrence was related to the extent of disease and prognosis of cervical adenocarcinoma with adverse pathologic features. A CA125 level of ≥50 U/mL may be a prognostic surrogate marker for cervical adenocarcinoma in patients with the presence of adverse factors.
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Purpose@#The optimal timing for radiotherapy (RT) after incomplete transarterial chemoembolization (TACE) remains unclear. This study investigated the optimal timing to initiate RT after incomplete TACE in patients with Barcelona Clinic Liver Cancer stage B hepatocellular carcinoma. @*Materials and Methods@#This study included 116 lesions in 104 patients who were treated with RT after TACE between 2001 and 2016. The time interval between the last TACE session and RT initiation was retrospectively analyzed. The optimal cut-off time interval that maximized the difference in local failure-free rates (LFFRs) was determined using maximally selected rank statistics. @*Results@#The median time interval was 26 days (range: 2–165 days). At a median follow-up of 18 months (range: 3–160 months), the median overall survival was 18 months. The optimal cut-off time interval appeared to be 5 weeks; using this cut-off, 65 and 39 patients were classified into early and late RT groups, respectively. Early RT group had a significantly poorer Child-Pugh class and higher alpha-fetoprotein levels compared to late RT group. Other characteristics, including tumor size (7 cm vs. 6 cm; p=0.144), were not significantly different between the groups. The 1-year LFFR was significantly higher in the early RT group than in the late RT group (94.6% vs. 70.8%; p=0.005). On multivariate analysis, early RT was identified as an independent predictor of favorable local failure-free survival (hazard ratio: 3.30, 95% confidence interval: 1.50–7.29; p=0.003). @*Conclusion@#The optimal timing for administering RT after incomplete TACE is within 5 weeks. Early administration of RT is associated with better local control.
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Purpose@#This study aimed to identify the prognostic value of early metabolic response assessed using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) during radiation therapy (RT) for cervical cancer. @*Materials and Methods@#We identified 116 patients treated with definitive RT, including FDG-PET/CT–guided intracavitary brachytherapy, between 2009 and 2018. We calculated parameters including maximum (SUVmax) and mean standardized uptake values (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for baseline FDG-PET/CT (PETbase) and image-guided brachytherapy planning FDG-PET/CT (PETIGBT). Multivariable analyses of disease-free survival (DFS) and overall survival (OS) were performed. @*Results@#We observed a time-dependent decrease in PET parameters between PETbase and PETIGBT; ΔSUVmax, ΔSUVmean, ΔMTV, and ΔTLG were 65%, 61%, 78%, and 93%, respectively. With a median follow-up of 59.5 months, the 5-year DFS and OS rates were 66% and 79%, respectively. Multivariable analysis demonstrated that ΔSUVmax ≥ 50% was associated with favorable DFS (hazard ratio [HR], 2.56; 95% confidence interval [CI], 1.14 to 5.77) and OS (HR, 5.14; 95% CI, 1.55 to 17.01). Patients with ΔSUVmax ≥ 50% (n=87) showed better DFS and OS than those with ΔSUVmax 50%, can help improve survival outcome predictions for patients with cervical cancer treated with definitive RT.
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Objective@#Kallikrein 5 (KLK5), which is frequently observed in normal cervico-vaginal fluid, is known to be related to prognosis in several solid tumors. We investigated the prognostic significance of KLK5 in uterine cervical cancer using tumor tissue microarray and immunohistochemistry staining. @*Methods@#We analyzed samples of 165 patients with uterine cervical cancer who received definitive radiation therapy between 2004 and 2012. We divided patients into two groups stratified by their KLK5 activity by immunohistochemistry staining: negative/weak (0–1+) (n=120 patients) and moderate/strong (2–3+) group (n=45 patients). Patient and tumor characteristics, patterns of failure, and survival outcomes were compared. Univariable and multivariable analyses were performed to identify prognostic factors. @*Results@#Patients with KLK5 2–3+ were younger (median: 52 vs. 60 years) and had frequent paraaortic lymph node involvement (40.0% vs. 18.3%) than those with KLK5 0–1+. With a median follow-up of 60.8 (interquartile range, 47.5–77.9) months, patients with KLK5 2–3+ had inferior 5-year locoregional recurrence-free survival and distant metastasis-free survival of 61.7% (vs. 77.5% in KLK5 0–1+ group) and 59.4% (vs. 72.8% in the KLK5 0–1+ group), respectively (all p<0.05). KLK5 2–3+ expression retained its significance after adjusting for other well-known prognostic factors of tumor size and stage in multivariable analysis. @*Conclusions@#KLK5 overexpression is associated with the aggressiveness of cervical cancer and may underlie the diminished response to conventional treatments. Therefore, KLK5 could be a reliable prognostic factor in cervical cancer.
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Objective@#Kallikrein 5 (KLK5), which is frequently observed in normal cervico-vaginal fluid, is known to be related to prognosis in several solid tumors. We investigated the prognostic significance of KLK5 in uterine cervical cancer using tumor tissue microarray and immunohistochemistry staining. @*Methods@#We analyzed samples of 165 patients with uterine cervical cancer who received definitive radiation therapy between 2004 and 2012. We divided patients into two groups stratified by their KLK5 activity by immunohistochemistry staining: negative/weak (0–1+) (n=120 patients) and moderate/strong (2–3+) group (n=45 patients). Patient and tumor characteristics, patterns of failure, and survival outcomes were compared. Univariable and multivariable analyses were performed to identify prognostic factors. @*Results@#Patients with KLK5 2–3+ were younger (median: 52 vs. 60 years) and had frequent paraaortic lymph node involvement (40.0% vs. 18.3%) than those with KLK5 0–1+. With a median follow-up of 60.8 (interquartile range, 47.5–77.9) months, patients with KLK5 2–3+ had inferior 5-year locoregional recurrence-free survival and distant metastasis-free survival of 61.7% (vs. 77.5% in KLK5 0–1+ group) and 59.4% (vs. 72.8% in the KLK5 0–1+ group), respectively (all p<0.05). KLK5 2–3+ expression retained its significance after adjusting for other well-known prognostic factors of tumor size and stage in multivariable analysis. @*Conclusions@#KLK5 overexpression is associated with the aggressiveness of cervical cancer and may underlie the diminished response to conventional treatments. Therefore, KLK5 could be a reliable prognostic factor in cervical cancer.
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OBJECTIVES: In our institutional experience, involved-field radiation therapy (IFRT) yields favorable outcomes in patients with recurrent epithelial ovarian cancer (EOC). This retrospective study aimed to investigate the clinical benefits of IFRT in this patient population. METHODS: Among patients treated with IFRT for recurrent EOC between 2010 and 2017, 61 patients with 90 treatments were included. IFRT encompassed all treatable lesions identified via imaging studies with 10–15-mm margins. Prescribed doses were ≥45 Gy (equivalent dose in 2 Gy/fraction). RESULTS: Patients were followed up for a median of 19.0 (Interquartile range, 8.6–34.9) months after IFRT. The 2-year in-field control, progression-free survival, and overall survival (OS) rates were 42.7%, 24.2%, and 78.9%, respectively. Fifty-three IFRT sessions (58.9%) were followed by systemic chemotherapy, and the median chemotherapy-free interval (CFI) was 10.5 (95% confidence interval=7.3–13.7) months. A higher carbohydrate antigen-125 (CA-125) level correlated with a worse 2-year OS (69.2% vs. 91.0%; p=0.001) and shorter median CFI (4.7 vs. 11.9 months; p12 months. For patients with a normal CA-125 level and/or platinum-sensitive tumor, IFRT prolonged CFI regardless of pre-existing carcinomatosis, gross tumor volume, and number of treatment sites. CONCLUSION: Our early experience demonstrates the safety and feasibility of IFRT as an effective salvage therapy and enables a “chemotherapy holiday” in selected recurrent EOC settings. The CA-125 value before IFRT (within normal range) and/or platinum sensitivity could be used as selection criteria for IFRT.
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Humans , CA-125 Antigen , Carcinoma , Disease-Free Survival , Drug Therapy , Ovarian Neoplasms , Patient Selection , Platinum , Retrospective Studies , Salvage Therapy , Tumor BurdenABSTRACT
PURPOSE: Early hypopharyngeal squamous cell carcinoma (HPSCC) is a rarely diagnosed disease, for which the optimal treatment has not been defined yet. We assessed patterns of failure and outcomes in early HPSCC treated with various therapeutic approaches to identify its optimal treatment. MATERIALS AND METHODS: Thirty-six patients with stage I (n = 10) and II (n = 26) treated between January 1992 and March 2014 were reviewed. Patients received definitive radiotherapy (RT) (R group, n = 10), surgery only (S group, n = 19), or postoperative RT (PORT group, n = 7). All patients in both the R and PORT groups received elective bilateral neck irradiation. In the S group, 7 patients had ipsilateral and 8 had bilateral dissection, while 4 patients had no elective dissection. RESULTS: At a median follow-up of 48 months, the 5-year locoregional control (LRC) rate was 65%. Six patients had local failure, 1 regional failure (RF), 3 combined locoregional failures, and 2 distant failures. There was no difference in 5-year LRC among the R, S, and PORT groups (p = 0.17). The presence with a pyriform sinus apex extension was a prognosticator related to LRC (p = 0.01) in the multivariate analysis. Patients with a bilaterally treated neck showed a trend toward a lower RF rate (p = 0.08). CONCLUSION: This study shows that patients with early stage HPSCC involving the pyriform sinus apex might need a tailored approach to improve LRC. Additionally, our study confirms elective neck treatment might have an efficacious role in regional control.
Subject(s)
Humans , Carcinoma, Squamous Cell , Cohort Studies , Follow-Up Studies , Hypopharyngeal Neoplasms , Multivariate Analysis , Neck , Pyriform Sinus , Radiotherapy , Treatment FailureABSTRACT
PURPOSE: This study investigates morphologic change of the rectosigmoid colon using a belly board in prone position and distended bladder in patients with rectal cancer. We evaluate the possibility of excluding the proximal margin of anastomosis from the radiation field by straightening the rectosigmoid colon. MATERIALS AND METHODS: Nineteen patients who received preoperative radiotherapy between 2006 and 2009 underwent simulation in a prone position (group A). These patients were compared to 19 patients treated using a belly board in prone position and a distended bladder protocol (group B). Rectosigmoid colon in the pelvic cavity was delineated on planning computed tomography (CT) images. A total dose of 45 Gy was planned for the whole pelvic field with superior margin of the sacral promontory. The volume and redundancy of rectosigmoid colon was assessed. RESULTS: Patients in group B had straighter rectosigmoid colons than those in group A (no redundancy; group A vs. group B, 10% vs. 42%; p = 0.03). The volume of rectosigmoid colon in the radiation field was significantly larger in group A (56.7 vs. 49.1 mL; p = 0.009). In dose volume histogram analysis, the mean irradiated volume was lower in patients in group B (V45 27.2 vs. 18.2 mL; p = 0.004). In Pearson correlation coefficient analysis, the in-field volume of rectosigmoid colon was significantly correlated with the bladder volume (R = 0.86, p = 0.003). CONCLUSION: Use of a belly board and distended bladder protocol could contribute to exclusion of the proximal margin of anastomosis from the radiation field.
Subject(s)
Humans , Anastomotic Leak , Colon , Prone Position , Radiotherapy , Rectal Neoplasms , Urinary BladderABSTRACT
PURPOSE: This study investigates morphologic change of the rectosigmoid colon using a belly board in prone position and distended bladder in patients with rectal cancer. We evaluate the possibility of excluding the proximal margin of anastomosis from the radiation field by straightening the rectosigmoid colon. MATERIALS AND METHODS: Nineteen patients who received preoperative radiotherapy between 2006 and 2009 underwent simulation in a prone position (group A). These patients were compared to 19 patients treated using a belly board in prone position and a distended bladder protocol (group B). Rectosigmoid colon in the pelvic cavity was delineated on planning computed tomography (CT) images. A total dose of 45 Gy was planned for the whole pelvic field with superior margin of the sacral promontory. The volume and redundancy of rectosigmoid colon was assessed. RESULTS: Patients in group B had straighter rectosigmoid colons than those in group A (no redundancy; group A vs. group B, 10% vs. 42%; p = 0.03). The volume of rectosigmoid colon in the radiation field was significantly larger in group A (56.7 vs. 49.1 mL; p = 0.009). In dose volume histogram analysis, the mean irradiated volume was lower in patients in group B (V45 27.2 vs. 18.2 mL; p = 0.004). In Pearson correlation coefficient analysis, the in-field volume of rectosigmoid colon was significantly correlated with the bladder volume (R = 0.86, p = 0.003). CONCLUSION: Use of a belly board and distended bladder protocol could contribute to exclusion of the proximal margin of anastomosis from the radiation field.