Programmed Death Ligand-1 and Tumor Burden Score Dictate Treatment Responses in Patients with Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma

BACKGROUND

The significance of tumor burden for survival is unknown for patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC). The purpose of our study was to evaluate the prognostic impact of programmed death ligand-1 (PD-L1) and tumor burden score (TBS) in patients with R/M HNSCC.

PATIENTS AND METHODS

R/M HNSCC patients who were treated with cisplatin, 5-fluorouracil plus cetuximab (EPF) or pembrolizumab (PPF) as first-line treatment were included in our study. PD-L1 and TBS were estimated and correlated with treatment responses. Kaplan-Meier curves were plotted for outcomes estimation.

RESULTS

A total of 252 R/M HNSCC patients were included, with 126 high tumor burden (HTB) and 126 low tumor burden (LTB) patients. Median progression-free survival (PFS) was 7.1 months in LTB and 3.9 months in HTB (p < 0.001) and median overall survival (OS) was 14.2 months in LTB and 9.2 months in HTB (p = 0.001). Patients with LTB had better PFS and OS than those with HTB independent of PD-L1 status. Subgroup analysis showed HTB patients treated with EPF had better survival than those treated with PPF, regardless of PD-L1 expression. For LTB PD-L1 positive patients, there was a longer survival with PPF than EPF, while for LTB PD-L1 negative patients, survival was similar between PPF and EPF. Multivariate analysis exhibited that tumor burden was significantly correlated with OS.

CONCLUSIONS

Tumor burden is significantly correlated with survival in patients with R/M HNSCC. PD-L1 and TBS should be taken into consideration to determine first-line treatment.

A Novel Prognostic Model Using Pan-Immune-Inflammation Value and Programmed Death Ligand 1 in Patients with Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma Receiving Immune Checkpoint Inhibitors: A Retrospective Multicenter Analysis

BACKGROUND

Little is known regarding the prognostication of the Pan-Immune-Inflammation Value (PIV) in patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC).

OBJECTIVES

This study aimed to investigate the prognostic role of PIV in patients with R/M HNSCC receiving immune checkpoint inhibitors (ICI).

PATIENTS AND METHODS

Patients who were diagnosed to have R/M HNSCC and treated with ICI were reviewed retrospectively. The cutoff value of PIV was set at the median. Patients were stratified into high PIV and low PIV. Kaplan-Meier curves were estimated for progression-free survival (PFS) and overall survival (OS).

RESULTS

A total of 192 patients were included in our study for oncologic outcomes evaluation. For the total population, the median PFS was 5.5 months and OS was 18.2 months. After stratification by PIV, median PFS was 11.7 months in the low PIV and 2.8 months in the high PIV groups (p < 0.001). The median OS was 21.8 months in the low PIV and 11.5 months in the high PIV groups (p < 0.001). Multivariate analysis demonstrated that PIV and PD-L1 were independent predictors associated with survival. A prognostic model using both PIV and PD-L1 was constructed. The median PFS was 12.2, 6.4, and 3.0 months for patients with risk scores of 0, 1, and 2, respectively (p < 0.001). The median OS was 23.7, 18.1, and 11.4 months for patients with risk scores of 0, 1, and 2, respectively (p < 0.001).

CONCLUSIONS

PIV is a prognostic biomarker in patients with R/M HNSCC treated with ICI. A prognostic model using PIV and PD-L1 could provide outcome prediction and risk stratification.

Prognostic impact of cortactin in patients with hypopharyngeal cancer and its role for tegafur-uracil maintenance after adjuvant chemoradiotherapy

The prognosis of patients with hypopharyngeal cancer (HPC) remains poor. Our study aims to investigate the prognostic impact of cortactin in patients with HPC and its role for tegafur-uracil (UFUR) maintenance after adjuvant chemoradiotherapy (CRT). Patients who were diagnosed to have HPC and underwent laryngopharyngectomy followed by adjuvant CRT were enrolled into our study. Immunohistochemical staining was performed for cortactin evaluation. Kaplan-Meier curves were depicted for recurrence-free survival (RFS) and overall survival (OS). A total of 157 patients were enrolled into our study. After stratified by cortactin, 53 patients were cortactin (+) and 104 patients were cortactin (-). The median RFS was 86.7 months in cortactin (-) and 10.2 months in cortactin (+) (P < 0.001). The median OS was 93.4 months in cortactin (-) and 16.9 months in cortactin (+) (P < 0.001). Patients were further classified according to UFUR maintenance or not after adjuvant CRT. In cortactin (+) patients, the median RFS and OS were 13.6 months versus 7.0 months (P = 0.006) and 24.0 months versus 10.0 months (P < 0.001) in UFUR (+) and UFUR (-), respectively. In cortactin (-) patients, the median RFS and OS were 96.0 months versus 72.2 months (P = 0.262) and 98.5 months versus 105.0 months (P = 0.665) in UFUR (+) and UFUR (-), respectively. Cortactin has a significantly impact in HPC patients. UFUR maintenance provided survival benefits in patients with cortactin (+) after adjuvant CRT.

Using machine learning algorithm to analyse the hypothyroidism complications caused by radiotherapy in patients with head and neck cancer

Machine learning algorithms were used to analyze the odds and predictors of complications of thyroid damage after radiation therapy in patients with head and neck cancer. This study used decision tree (DT), random forest (RF), and support vector machine (SVM) algorithms to evaluate predictors for the data of 137 head and neck cancer patients. Candidate factors included gender, age, thyroid volume, minimum dose, average dose, maximum dose, number of treatments, and relative volume of the organ receiving X dose (X: 10, 20, 30, 40, 50, 60 Gy). The algorithm was optimized according to these factors and tenfold cross-validation to analyze the state of thyroid damage and select the predictors of thyroid dysfunction. The importance of the predictors identified by the three machine learning algorithms was ranked: the top five predictors were age, thyroid volume, average dose, V50 and V60. Of these, age and volume were negatively correlated with thyroid damage, indicating that the greater the age and thyroid volume, the lower the risk of thyroid damage; the average dose, V50 and V60 were positively correlated with thyroid damage, indicating that the larger the average dose, V50 and V60, the higher the risk of thyroid damage. The RF algorithm was most accurate in predicting the probability of thyroid damage among the three algorithms optimized using the above factors. The Area under the receiver operating characteristic curve (AUC) was 0.827 and the accuracy (ACC) was 0.824. This study found that five predictors (age, thyroid volume, mean dose, V50 and V60) are important factors affecting the chance that patients with head and neck cancer who received radiation therapy will develop hypothyroidism. Using these factors as the prediction basis of the algorithm and using RF to predict the occurrence of hypothyroidism had the highest ACC, which was 82.4%. This algorithm is quite helpful in predicting the probability of radiotherapy complications. It also provides references for assisting medical decision-making in the future.

Platinum Plus Tegafur-Uracil versus Platinum Alone during Concurrent Chemoradiotherapy in Patients with Nonmetastatic Nasopharyngeal Carcinoma: A Propensity-Score-Matching Analysis

Concurrent chemoradiotherapy (CCRT) with a cisplatin-based regimen is the standard treatment for patients with nasopharyngeal carcinoma (NPC). Our study was a propensity-score-matching analysis and it aimed to investigate the oncologic outcomes of platinum plus tegafur−uracil versus platinum alone during CCRT in patient with nonmetastatic NPC. Patients with pathologic confirmed NPC in 2018−2022 were reviewed. Patients treated with platinum plus tegafur−uracil (CCRT-UP) or platinum alone (CCRT-P) during CCRT were recruited into this study. A propensity-score-matching analysis was conducted to diminish the selection bias. The recurrence-free survival (RFS) and overall survival (OS) were presented with Kaplan−Meier curves. The treatment-related adverse effects (AEs) were recorded according to the National Cancer Institute’s Common Terminology Criteria V3.0. A total of 44 patients with CCRT-UP and 44 patients with CCRT-P were identified after propensity score matching. The median RFS was not reached (NR) in the CCRT-UP group, and it was 12.5 months in the CCRT-P group (p < 0.001). The median OS was NR in the CCRT-UP group, and it was 15.9 months in the CCRT-P group (p < 0.001). The overall response rate and disease-control rate were insignificant between the CCRT-UP and CCRT-P groups. A subgroup analysis showed that the median OS was significantly longer in the CCRT-UP group than in the CCRT-P group, regardless of the clinical stage. A multivariate analysis exhibited that CCRT-UP was independently correlated with survival. The grade 3−4 AEs were insignificant between the CCRT-UP and CCRT-P arms. CCRT-UP had better RFS and OS in nonmetastatic NPC patients with similar toxic profiles. Further larger-scaled prospective randomized control trials are warranted to validate our conclusions.

5-Methoxytryptophan Sensitizing Head and Neck Squamous Carcinoma Cell to Cisplatitn Through Inhibiting Signal Transducer and Activator of Transcription 3 (STAT3)

Head and neck squamous cell carcinoma (HNSCC) is a common cancer of the oral cavity. Cisplatin (CDDP) is the ideal chemo-radiotherapy used for several tumor types, but resistance to the drug has become a major obstacle in treating patients with HNSCC. 5-methoxytryptophan (5-MTP), a 5-methoxyindole metabolite of tryptophan metabolism, reduces inflammation-mediated proliferation and metastasis. This study aimed to assess the anti-oral cancer activity of 5-MTP when used alone or in combination with CDDP. Results showed that CDDP dose dependently reduced the growth of SSC25 cells but not 5-MTP. The combination of CDDP and 5-MTP exerted additional inhibitory effect on the growth of SSC25 cells by attenuating the phosphorylation of STAT3. In the 4-nitroquinoline-1-oxide-induced oral cancer mouse model, 5-MTP sensitized the reduction effect of CDDP on tumorigenesis, which restricted the tongue tissue in hyperkeratotic lesion rather than squamous cell carcinoma. The combination of CDDP and 5-MTP may be a potent therapeutic strategy for HNSCC patients with radiotherapy.

Tegafur-Uracil versus 5-Fluorouracil in Combination with Cisplatin and Cetuximab in Elderly Patients with Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma: A Propensity Score Matching Analysis

Simple Summary

Elderly patients with recurrent or metastatic head and neck squamous cell carcinoma are a unique subset because they are at increased risks of miserable prognosis. Although cisplatin, 5-fluorouracil plus cetuximab (EXTREME) is the most commonly used regimen, chemotherapy de-escalation strategy was suggested in elderly patients due to toxicity. Herein, an oral tegafur–uracil is usually substituted for 5-fluorouracil and combined with cisplatin plus cetuximab (UPEx) as a novel agent for elderly patients with recurrent or metastatic head and neck squamous cell carcinoma. The median progression-free survival was 5.4 months in UPEx and 5.8 months in EXTREME (p = 0.451). The median overall survival was 10.8 months in UPEx and 10.2 months in EXTREME (p = 0.807). Grade 3/4 adverse events were much fewer in UPEx than in EXTREME (p < 0.001). Our study demonstrated that UPEx is effective with improving safety profiles. We suggested UPEx might be a better treatment option for elderly patients with recurrent or metastatic head and neck squamous cell carcinoma.

Abstract

There are increasing incidences of elderly patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC). However, the treatment is not yet established. We conducted a propensity score matching analysis to evaluate the efficacy and safety of tegafur–uracil versus 5-fluorouracil in combination with cisplatin plus cetuximab in elderly patients with R/M HNSCC. Elderly patients with R/M HNSCC treated with cetuximab-containing chemotherapy were recruited into this study. In order to reduce the selection bias, propensity score matching was performed. Kaplan–Meier curves were plotted for progression-free survival (PFS) and overall survival (OS). Toxicities were graded according to the National Cancer Institute’s Common Terminology Criteria V3.0. After propensity sore matching, 54 patients with tegafur–uracil, cisplatin plus cetuximab (UPEx), and 54 patients with 5-fluorouracil, cisplatin plus cetuximab (EXTREME) were identified. The median PFS was 5.4 months in UPEx and 5.8 months in EXTREME (p = 0.451). The median OS was 10.8 months in UPEx and 10.2 months in EXTREME (p = 0.807). The overall response rate (ORR) and disease control rate (DCR) were insignificant in both arms, accounting for 61% versus 59% (p = 0.680) and 72% versus 70% (p = 0.732) in the UPEx arm and the EXTREME arm, respectively. A multivariate analysis showed that age and ECOG PS were, independently, predictors. Grade 3/4 adverse events were much fewer in UPEx than in EXTREME (p < 0.001). Both cetuximab-containing chemotherapies are effective in elderly patients with R/M HNSCC. Safety profiles are improved when tegafur–uracil is substituted for 5-fluorouracil. Further prospective studies are warranted to validate our conclusions.

Outcomes of patients with nasopharyngeal carcinoma treated with intensity-modulated radiotherapy

Nasopharyngeal cancer shows a good response to intensity-modulated radiotherapy. However, there is no clear evidence for the benefits of routine use of image-guided radiotherapy. The purpose of this study was to perform a retrospective investigation of the treatment outcomes, treatment-related complications and prognostic factors for nasopharyngeal cancer treated with intensity-modulated radiotherapy and image-guided radiotherapy techniques. Retrospective analysis was performed on 326 consecutive nasopharyngeal cancer patients treated between 2004 and 2015. Potentially significant patient-related and treatment-related variables were analyzed. Radiation-related complications were recorded. The 5-year overall survival and disease-free survival rates of these patients were 77.9% and 70.5%, respectively. Age, AJCC (American Joint Committee on Cancer) stage, retropharyngeal lymphadenopathy, treatment interruption and body mass index were independent prognostic factors for overall survival. Age, AJCC stage, retropharyngeal lymphadenopathy, image-guided radiotherapy and body mass index were independent prognostic factors for disease-free survival. In conclusion, intensity-modulated radiotherapy significantly improves the treatment outcomes of nasopharyngeal cancer. With the aid of image-guided radiotherapy, the advantage of intensity-modulated radiotherapy might be further amplified.

PI3k inhibitors (BKM120 and BYL719) as radiosensitizers for head and neck squamous cell carcinoma during radiotherapy

Approximately 500,000 new cases of head and neck squamous cell carcinoma (HNSCC) are reported annually. Radiation therapy is an important treatment for oral squamous cell carcinoma (OSCC). The survival rate of patients with HNSCC remained low (50%) in decades because of radiation therapy failure caused by the radioresistance of HNSCC cells. This study aimed to identify PI3K inhibitors that can enhance radiosensitivity. Results showed that pan-Phosphoinositide 3-kinases (PI3K) inhibitor BKM120 and class I α-specific PI3K inhibitor BYL719 dose-dependently reduced the growth of OSCC cells but not that of radioresistant OML1-R cells. The combination treatment of BKM120 or BYL719 with radiation showed an enhanced inhibitory effect on OSCC cells and radioresistant OML1-R cells. Furthermore, the enhanced inhibitory effect of the combination treatment was confirmed in patient-derived OSCC cells. The triple combination treatment of mTOR inhibitor AZD2014 and BKM120 or AZD2014 and BYL719 with radiation showed a significantly enhanced inhibitory effect on radioresistant OML1-R cells. These results suggest that the PI3K inhibitors are potential therapeutic agents with radiosensitivity for patients with OSCC.

Haemorrhage rates of ruptured and unruptured brain arteriovenous malformation after radiosurgery: a nationwide population-based cohort study

OBJECTIVES

The present nationwide population-based cohort study aims to assess the effectiveness of gamma knife radiosurgery (GKS) on ruptured and unruptured brain arteriovenous malformations (AVMs) by evaluating the haemorrhage rates.

DESIGN

A nationwide, retrospective cohort study.

SETTING

Taiwan National Health Insurance Research Database (NHIRD).

PARTICIPANTS

An observational study of 1515 patients who were diagnosed with brain AVMs between 1997 and 2013 from the Taiwan NHIRD.

PRIMARY OUTCOME AND SECONDARY OUTCOME MEASURES

We performed a survival analysis using the Kaplan-Meier method. Multivariate Cox proportional hazards regression models were used to explore the relationship between treatment modalities (GKS vs non-GKS) and haemorrhage, adjusted for age and sex.

RESULTS

The GKS and non-GKS groups included 317 and 1198 patients, respectively. Patients in the GKS group (mean±SD, 33.08±15.48 years of age) tended to be younger than those in the non-GKS group (37.40±17.62) (p<0.001). The 15-year follow-up revealed that the rate of bleeding risk was lower in the GKS group than in the non-GKRS group (adjusted HR (aHR) 0.61; 95% CI 0.40 to 0.92). The bleeding risk of ruptured AVMs was significantly lower in GKS group than in the non-GKS group (aHR 0.34; 95% CI 0.19 to 0.62). On the other hand, the bleeding risk of unruptured AVMs was higher in the GKS group than in the non-GKS group (aHR 1.95; 95% CI 1.04 to 3.65). In the unruptured AVM group, the incidence of bleeding was significantly higher among patients in the GKS group that were of >40 years of age (aHR 3.21; 95% CI 1.12 to 9.14).

CONCLUSIONS

GKS is safe and it reduces the risk of haemorrhage in patients with ruptured AVMs. The administration of GKS to patients with unruptured AVMs who are above the age of 40 years old male might increase the risk of haemorrhage.

Calibration of Gafchromic EBT Film Using the Microtek ScanMaker 9800XL Plus Flatbed Scanner with a Modified One Red-Channel after Three-Channel Method

Purpose:

Using the Microtek ScanMaker 9800XL Plus (9800XL⁺) flatbed scanner, a method is presented to accurately calibrate EBT film, which cannot be calibrated simply using a general three-channel method because of the nonhomogeneous scanning.

Materials and Methods:

Through the percentage-depth-dose method, 6-MV photon beams with two different monitor units were delivered to eight EBT2 films, each of which was tightly sandwiched in a 30-cm cubic polystyrene phantom and positioned parallel to the central axis of the beam. Before and after irradiation, all films were scanned using the Microtek 9800XL⁺ scanner and the pixel values (PVs) were measured along the central axis of the beam on the film and fitted to the corresponding depth doses. Before calibration, the irradiated film image was first modified using a template matrix, which was generated using the prescanned background images. Then, a modified one red-channel after three-channel method was used to calibrate the film.

Results:

Without a template matrix, the three-channel method cannot be used because the PVs do not correspond to a rational fitting form. Using the proposed method, the difference between the fitted dose and the delivered dose is <2%. The green channel, and not the red, is found to have the largest dynamic range.

Conclusion:

The proposed technique allows the use of the three-channel method to calibrate film using a Microtek 9800XL⁺ scanner.

An innovative method to acquire the location of point A for cervical cancer treatment by HDR brachytherapy

Brachytherapy of local cervical cancer is generally accomplished through film‐based treatment planning with the prescription directed to point A, which is invisible on images and is located at a high‐dose gradient area. Through a standard reconstruction method by digitizing film points, the location error for point A would be 3 mm with a condition of 30° curvature tandem, which is 10° away from the gantry rotation axis of a simulator, and has an 8.7 cm interval between the flange and the isocenter. To reduce the location error of the reconstructed point A, this paper proposes a method and demonstrates its accuracy. The Cartesian coordinates of point A were derived by acquiring the locations of the cervical os (tandem flange) and a dummy seed located in the tandem above the flange. To verify this analytical method, ball marks in a commercial “Isocentric Beam Checker” were selected to simulate the two points A, the os, and the dummies. The Checker was placed on the simulator couch with its center ball coincident with the simulator isocenter and its rotation axis perpendicular to the gantry rotation axis. With different combinations of the Checker and couch rotation angles, the orthogonal films were shot and all coordinates of the selected points were reconstructed through the treatment planning system and compared with that calculated through the analytical method. The position uncertainty and the deviation prediction of point A were also evaluated. With a good choice of the reference dummy point, the position deviations of point A obtained through this analytical method were found to be generally within 1 mm, with the standard uncertainty less than 0.5 mm. In summary, this new method is a practical and accurate tool for clinical usage to acquire the accurate location of point A for the treatment of cervical cancer patient.

PACS number(s): 87.55.km

Calibration of EBT2 film using a red-channel PDD method in combination with a modified three-channel technique

PURPOSE

Ashland Inc. EBT2 and EBT3 films are widely used in quality assurance for radiation therapy; however, there remains a relatively high degree of uncertainty [B. Hartmann, M. Martisikova, and O. Jakel, "Homogeneity of Gafchromic EBT2 film," Med. Phys. 37, 1753-1756 (2010)]. Micke et al. (2011) recently improved the spatial homogeneity using all color channels of a flatbed scanner; however, van Hoof et al. (2012) pointed out that the corrected nonuniformity still requires further investigation for larger fields. To reduce the calibration errors and the uncertainty, the authors propose a new red-channel percentage-depth-dose method in combination with a modified three-channel technique.

METHODS

For the ease of comparison, the EBT2 film image used in the authors' previous study (2012) was reanalyzed using different approaches. Photon beams of 6-MV were delivered to two different films at two different beam on times, resulting in the absorption doses of ranging from approximately 30 to 300 cGy at the vertical midline of the film, which was set to be coincident with the central axis of the beam. The film was tightly sandwiched in a 30(3)-cm(3) polystyrene phantom, and the pixel values for red, green, and blue channels were extracted from 234 points on the central axis of the beam and compared with the corresponding depth doses. The film was first calibrated using the multichannel method proposed by Micke et al. (2010), accounting for nonuniformities in the scanner. After eliminating the scanner and dose-independent nonuniformities, the film was recalibrated via the dose-dependent optical density of the red channel and fitted to a power function. This calibration was verified via comparisons of the dose profiles extracted from the films, where three were exposed to a 60° physical wedge field and three were exposed to composite fields, and all of which were measured in a water phantom. A correction for optical attenuation was implemented, and treatment plans of intensity modulated radiation therapy and volumetric modulated arc therapy were evaluated.

RESULTS

The method described here demonstrated improved accuracy with reduced uncertainty. The relative error compared with the measurements of a water phantom was less than 1%, and the overall calibration uncertainty was less than 2%. Verification tests revealed that the results were close to those of the authors' previous study, and all differences were within 3%, except those with a high-dose gradient. The gamma pass rates (2%/2 mm) of the treatment plan evaluated using the method described here were greater than 99%, and no obvious stripe patterns were observed in the dose-difference maps.

CONCLUSIONS

Spatial homogeneity was significantly improved via the calibration method described here. This technique is both convenient and time-efficient because it does not require cutting the film, and only two exposures are necessary.

Geometric error of cervical point A calculated through traditional reconstruction procedures for brachytherapy treatment

Brachytherapy used in local cervical cancer is still widely based on 2D standard dose planning with the prescription to point A, which is invisible on imaging and located at a high‐dose gradient. In this study, the geometric location error of point A was investigated. It is traditionally reconstructed in the treatment planning system after carefully digitizing the point marks that were previously drawn on the orthogonal radiographs into the system. Two Cartesian coordinates of point A were established and compared. One was built up based on the geometric definition of point A and would be taken as the true coordinate, while the other was built up through traditional clinical treatment procedures and named as the practical coordinate. The orthogonal film reconstruction technique was used and the location error between the practical and the true coordinate introduced from the variations of, first, the angle between the tandem and the simulator gantry rotation axis, and second, the interval between the tandem flange and the simulator isocenter, was analyzed. The location error of point A was higher if the tandem was rotated away from the gantry rotation axis or if the location of the tandem flange was set away from the isocenter. If a tandem with a 30° curvature was rotated away from the gantry rotation axis 10° in the anterior–posterior (AP) view, and there was an 8.7 cm interval between the flange and the isocenter, the location error of point A would be 3 mm without including other errors from simulator calibration, data input, patient setup, and movements. To reduce the location error of point A calculated for traditional reconstruction procedures, it is suggested to move the couch or patient to make the mid‐point of two points A near the isocenter and the tandem in the AP view parallel to the gantry rotation axis as much as possible.

PACS number: 87.55.km

The role of radiotherapy in the treatment of hepatocellular carcinoma with portal vein tumor thrombus

The aim of this study was to evaluate the role of radiotherapy in the treatment of hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVT) and to determine the prognostic factors for overall survival. Altogether, 106 patients with HCC and PVT referred for radiotherapy between 2004 and 2009 were retrospectively reviewed. A total of 60 Gy in 30 daily fractions was delivered with intensity-modulated radiotherapy techniques. Patient-related and treatment-related factors were analyzed to evaluate their prognostic significance for the overall survival rate. Complete response was noted in 10 patients and partial response in 55 patients. The liver lesions had become resectable after the completion of radiotherapy in 12 patients, and surgery was subsequently performed. One or two courses of transarterial chemoembolization (TACE) were administered to 19 patients following radiotherapy. The 1-year and 2-year overall survival rates were 34.7% and 11%, respectively, and the median survival was 7 months for the entire cohort of patients. Post-radiotherapy treatment modality, response to radiotherapy and JIS score were demonstrated as independent prognostic factors for overall survival (P = 0.003, P < 0.001, P < 0.001, respectively). For patients who received surgical intervention after radiotherapy, the median survival was 30 months and the 2-year overall survival rate was 67%. Radiotherapy achieved a 61.5% objective response rate and prolonged survival in patients with PVT. The liver tumors had become resectable after radiotherapy in 11% of patients. Our results suggested that radiotherapy could offer survival benefits and should be considered as a treatment option for patients with PVT. Radiotherapy could also be considered as a preoperative treatment modality in patients with HCC and PVT.

A light field-based method to adjust rounded leaf end MLC position for split shape dose calculation correction in a radiation therapy treatment planning system

We present an analytical and experimental study of split shape dose calculation correction by adjusting the position of the round leaf end position in an intensity-modulated radiation therapy treatment planning system. The precise light field edge position (Xtang.p ) was derived from 50% of the central axis dose created by nominal light field using geometry and mathematical methods. Leaf position (Xmlc.p), defined in the treatment planning system for monitor unit calculation, could be derived from Xtang.p. Offset (correction) could be obtained by the position corresponding to 50% of the central axis dose minus the Xmlc.p position. For SSD from 90 cm to 120 cm at 6 MV and 10 MV, the 50% dose position was located outside of Xmlc,p in the MLC leaf position range of +8 cm to -8 cm, where the offset correction positively increased, whereas the offset correction negatively increased when the MLC leaf position was in the range of -12 cm to -8 cm and +20 cm to +8 cm when the 50% position was located inside Xmlc,p. The monitor unit calculation could provide underdosage or overdosage of 7.5% per mm without offset correction. Calibration could be performed at a certain SSD to fit all SSD offset corrections. With careful measurement and an accurate offset correction, it is possible to achieve the dose calculation with 0.5% error for the adjusted MLC leaf edge location in the treatment planning system.

Radiotherapy for head and neck cancer

Treatment for patients with head and neck cancer requires a multidisciplinary approach. Radiotherapy is employed as a primary treatment or as an adjuvant to surgery. Each specific subsite dictates the appropriate radiotherapy techniques, fields, dose, and fractionation scheme. Quality of life is also an important issue in the management of head and neck cancer. The radiation-related complications have a tremendous impact on the quality of life. Modern radiotherapy techniques, such as intensity-modulated radiotherapy and image-guided radiotherapy, can offer precise radiation delivery and reduce the dose to the surrounding normal tissues without compromise of target coverage. In the future, efforts should be made in the exploration of novel strategies to improve treatment outcome in patients with head and neck cancer.

A conceptual design of rotating board technique for delivering total skin electron therapy

PURPOSE

This study presents a novel technique in which a uniform radiation dose to the whole body, soles, and scalp vertex can be achieved in one electron beam treatment fraction.

METHODS

The patient was treated at a machine with a home-made rotating board. The patients were treated in two groups in the prone and supine positions by leaning onto an inner rotational board in the prone and supine positions. Each group can further be separated into two subgroups using tilting and rotational positions for treatment.

RESULTS

One of the beams was directed 15.5 degrees upward and 15.5 degrees downward from the horizontal axis to provide a field size of as large as 200 cm in height and 140 cm in width. An incline angle of 31.5 degrees anteriorly (forward) or posteriorly (backward) of the outer frame at an angle rotated 60 degrees clockwise or counterclockwise to the inner frame was found to be most appropriate. The output for the rotating board total skin electron therapy (RB-TSET) was 0.046 cGy/MU at ISD of 350 cm. The beam characteristics of the RB-TSET depth dose curves were R50 = 2.48 cm, dmax = 0.7 cm, E0 = 5.78 MeV, and Rp = 3.4 cm.

CONCLUSIONS

The RB-TSET technique presented in this study is able to deliver a uniform radiation dose to the patient's skin surface, the scalp vertex, and soles of the feet all at one time, eliminating the trouble of having to further irradiate these two regions separately when using the Stanford six field technique.

Dose Escalation for Patients With Locally Advanced Nasopharyngeal Carcinoma Treated With Radiotherapy Alone

OBJECTIVES

The local control of patients with locally advanced nasopharyngeal carcinoma is still unsatisfactory. This prospective study was designed to evaluate the treatment outcomes and treatment-related complications of patients with locally advanced nasopharyngeal carcinoma treated with escalated radiation doses.

METHODS

A total of 118 consecutive patients with T4 classification (1992 American Joint Committee on Cancer staging system), histology-proven nonmetastatic nasopharyngeal carcinoma were treated with radiotherapy alone between 1992 and 1997 in a medical center in southern Taiwan. Thirty-two of them were enrolled into a prospective study of dose escalation and were irradiated to a total of 81 Gy. The other 86 patients received a total of 70.2 Gy. Potentially significant patient-related and treatment-related parameters were analyzed for their prognostic significance. Radiation-related complications were recorded and analyzed.

RESULTS

The 5-year local progression-free rates were 61%, and 61% for patients receiving 70.2 Gy and 81 Gy, respectively (P > 0.05). The incidences of xerostomia, hearing impairment, and temporal radionecrosis were significantly higher for those receiving 81 Gy. The 5-year complication-free rates of patients receiving 70.2 Gy and 81 Gy were 14% versus 2% for xerostomia (P = 0.0070), 50% versus 30% for hearing impairment (P = 0.0198), and 91% versus 82% for temporal radionecrosis (P = 0.0400).

CONCLUSIONS

For patients with locally advanced nasopharyngeal carcinoma treated with radiotherapy alone, dose escalation to 81 Gy failed to show benefits on local control rate. Higher radiation doses contribute to a higher incidence of radiation-related complications.

Treatment outcomes of patients with AJCC stage IVC nasopharyngeal carcinoma: benefits of primary radiotherapy

BACKGROUND

There is no agreement on the optimal management of patients initially presenting with metastatic nasopharyngeal carcinoma. This study was performed to investigate the treatment outcomes and to assess whether radiotherapy to the primary tumors has survival benefits.

METHODS

From 1993 to 2001, 806 consecutive patients with histology-proven nasopharyngeal carcinoma were registered at our department. Among them, 125 patients had distant metastases and fulfilled the criteria for stage IVC of the 1997 American Joint Committee on Cancer staging system. Tumor histology according to the World Health Organization classification was Type 2 in 67 patients and Type 3 in 58 patients. The most common site of initial metastasis was bone. A total of 28 patients refused any treatment, 39 received chemotherapy alone and 58 had radiotherapy to the primary tumor sites alone.

RESULTS

The 1 year overall survival rates were 25, 36 and 48% for patients with no treatment, chemotherapy and radiotherapy, respectively. In multivariate analysis, age of diagnosis and treatment modality were confirmed as independent prognostic factors for overall survival.

CONCLUSIONS

Based on our results, radiotherapy to the primary tumor sites could be considered for patients with stage IVC nasopharyngeal carcinoma. A combination of radiotherapy and chemotherapy might have potential survival benefits. Further randomized prospective study is necessary to explore the optimal treatment strategy.

Treatment outcomes and late complications of 849 patients with nasopharyngeal carcinoma treated with radiotherapy alone

PURPOSE

The objective of this study was to describe the treatment outcomes and treatment-related complications of nasopharyngeal carcinoma (NPC) patients treated with radiotherapy alone.

METHODS AND MATERIALS

Retrospective analysis was performed on 849 consecutive NPC patients treated between 1983 and 1998 in our institution. Potentially significant patient-related and treatment-related variables were analyzed. Radiation-related complications were recorded.

RESULTS

The 5-year overall and disease-free survival rates of these patients were 59% and 52%, respectively. Advanced parapharyngeal space (PPS) invasion showed stronger prognostic value than PPS invasion. Multiple neck lymph node (LN) involvement was demonstrated to be one of the most powerful independent prognostic factors among all LN-related parameters. External beam radiation dose more than 72 Gy was associated with significantly higher incidence of hearing impairment, trismus, and temporal lobe necrosis.

CONCLUSIONS

We recommend that the extent of PPS should be clarified and stratified. Multiple neck LN involvement could be integrated into the N-classification in further revisions of the American Joint Committee on Cancer stage. Boost irradiation is not suggested for node-negative necks. For node-positive necks, boost irradiation is indicated and a longer interval between initial and boost irradiation would reduce the incidence of neck fibrosis without compromising the neck control rate.

Treatment outcomes and prognostic factors of patients with supratentorial low-grade oligodendroglioma

PURPOSE

Oligodendroglioma is a relatively rare central nervous system tumor. Currently, surgical intervention is the mainstay of treatment, and the role of postoperative radiotherapy (RT) remains a subject of controversy. The objective of this study was to investigate the prognostic factors, evaluate the treatment outcomes, and assess whether postoperative RT has a benefit on local control and overall survival rates.

METHODS AND MATERIALS

This was a retrospective review of 52 consecutive adult patients with supratentorial low-grade oligodendrogliomas diagnosed at our institution between September 1980 and September 1998. Thirty-two received postoperative RT. Data were analyzed retrospectively to survey the significant prognostic factors for local control and overall survival.

RESULTS

The 5-year overall and progression-free survival rate was 80% and 67%, respectively. Twenty-five patients experienced local disease progression during the follow-up period. In multivariate analysis, postoperative RT and age at diagnosis showed independent prognostic significance for overall survival. For progression-free survival, postoperative RT was the only independent prognostic factor.

CONCLUSION

On the basis of the results of this study, we recommend considering postoperative RT as one of the standard adjuvant treatment modalities for patients with supratentorial low-grade oligodendroglioma, regardless of the extent of surgical resection. The optimal treatment strategy to maximize the treatment outcome should still be explored.

Intensity-modulated radiotherapy versus conventional three-dimensional conformal radiotherapy for boost or salvage treatment of nasopharyngeal carcinoma

PURPOSE

To compare intensity-modulated radiotherapy (IMRT) and conventional three-dimensional conformal radiotherapy (3D-CRT) for the boost treatment of new-onset nasopharyngeal carcinoma (NPC) or the salvage treatment of locally recurrent NPC.

METHODS AND MATERIALS

Between January 14 and February 23, 2000, 5-field 3D-CRT treatment plans were generated for 14 consecutive NPC patients using the ADAC Pinnacle planning system in Chang Gung Memorial Hospital, Kaohsiung, Taiwan. The planning data of these patients were later transferred to Memorial Sloan-Kettering Cancer Center, where new IMRT plans, also using 5-7 radiation fields were created for each patient using an inverse treatment planning system. The IMRT and 3D-CRT plans were compared for all 14 patients. The relationship between the anatomic shapes and locations of targets and the results of different plans were studied.

RESULTS

Target doses were more homogeneous in IMRT plans. The average maximal brainstem dose (D(05), the dose received by 5% of the brainstem volume) decreased from 30.9% of the prescription dose with 3D-CRT to 15.3% and 14.7% with 5- and 7-field IMRT, respectively (p = 0.004 and 0.003, respectively, compared with 3D-CRT, paired Student's t test). Five anatomic factors were found that predicted greater benefits with IMRT. These factors were (1) vertical length of target >7 cm, (2) minimal distance between target and brainstem <0.1 cm, (3) maximal AP overlap of target and brainstem >0.6 cm, (4) maximal AP overlap of target and spinal cord >1 cm, and (5) vertical overlap of target and eyes >0 cm. For the 7 patients with at least 1 of these 5 anatomic factors, the benefits achieved by IMRT planning would have been greater than the benefits for the other 7 patients (p = 0.005, Fisher's exact test).

CONCLUSION

For boost or salvage treatment of NPC, lower normal tissue doses and more homogeneous target doses were achieved with IMRT plans. For NPC patients with at least 1 of the 5 anatomic factors, IMRT is highly recommended.

Postoperative radiation therapy for medulloblastoma--high recurrence rate in the subfrontal region

PURPOSE

To investigate the treatment results and analyze the prognostic factors for patients with medulloblastoma (MB) treated by surgery and postoperative radiation therapy (RT).

METHODS AND MATERIALS

Thirty-five patients of MB receiving surgery followed by RT from February 1986 to September 1999 were reviewed. Their median age was 12 years with a slight male predominance. Twenty-four (69%) patients had total resection of tumor. Most (86%) cases received craniospinal irradiation (CSI). Adequate dose (craniospinal dose > 30 Gy and posterior fossa dose > or = 50 Gy) was given in 26 (74%) patients.

RESULTS

The median survival duration was 48 months. The 5-year and 10-year overall survival rates were 63% and 40%, respectively. Univariate analysis revealed that stage, shunt surgery, RT dose, and protracted RT course were significant factors in predicting overall survival (OS), disease-free survival (DFS), and/or posterior fossa control (PFC). Multivariate analysis showed that RT dose affected OS and PFC independently, stage influenced OS and DFS, while protracted RT course impacted DFS. A total of 20 cases developed disease relapse. The median time to relapse was 18 months. The posterior fossa (10 cases) was the most common site of first failure, followed by the subfrontal lobe (7 cases), spine (6 cases), and other areas (4 cases).

CONCLUSION

Our results were compatible with others, except that more subfrontal relapses were found. Surgical resection followed by standard dose and adequate margin of CSI are recommended as the mainstays of treatment.

Attenuation of radiation dose by the skull base bone in patients with nasopharyngeal carcinoma: clinical importance

PURPOSE

To measure the degree of attenuation of radiation dose by the skull base bone in patients with nasopharyngeal carcinoma (NPC) and to study its clinical importance.

MATERIALS AND METHODS

Isodose distribution in 11 patients with NPC who received bilaterally opposed large-field irradiation (1.8 Gy per fraction) was studied with a three-dimensional treatment planning system with tissue inhomogeneity correction. Also studied were the sites of local tumor recurrence in 37 patients with NPC and skull base destruction (>/=0.5 cm) or intracranial invasion treated with radiation therapy from January 1989 to December 1992. Regression analyses were performed.

RESULTS

In the dosimetric study, the low-dose areas (<1.65 Gy) were located at the level of the skull base in all 11 patients. A significantly positive correlation between the maximum width of the skull base bone and the low-dose volume (<1.65 Gy) was demonstrated (P =.003, linear regression). In the clinical study, local tumor recurrence was noted in 18 patients (49%). The sites of local recurrence included skull base in 16 patients (43%) and nasopharynx in six patients (16%). Wider skull base bone was a significant predictor of skull base recurrence after radiation therapy (P =.03, logistic regression).

CONCLUSION

Herein demonstrated is the inadequacy of the radiation dose over the skull base due to attenuation by the skull base bone. The relationship between width of skull base bone and skull base tumor recurrence also is established.

Multivariate analysis of pulmonary fibrosis after electron beam irradiation for postmastectomy chest wall and regional lymphatics: evidence for non-dosimetric factors

BACKGROUND AND PURPOSE

To evaluate the factors associated with pulmonary fibrosis after postmastectomy electron beam irradiation of chest wall and regional lymphatics in patients with breast cancer.

MATERIALS AND METHODS

From July 1987 through July 1994, 109 women with stage II and III breast cancer receiving modified radical mastectomies were managed by postoperative electron beam irradiation. Doses of 46 to 50.4 Gy were delivered to the chest wall covered with bolus, internal mammary nodes, supraclavicular nodes and axillary lymph nodes via 12 or 15 MeV single portal electron beam. Seventeen patients received additional 10-16 Gy surgical scar boost via 9 MeV electron beam. Comparison of pre-treatment and post-treatment chest X-ray films were used to monitor the development of pulmonary fibrosis.

RESULTS

Only Grade 1 radiation-induced late pulmonary toxicity was noted in 33 patients (29%). Twenty-six patients (24%) developed pulmonary fibrosis under unbolused chest wall. Lung fibrosis under bolused chest wall was noted in 11 patients (10%). Statistical difference (P<0.01) was noted between the incidence of fibrosis in these two sites. In multivariate analysis of lung fibrosis under unbolus-covered chest wall, the independent prognostic factors are low body mass index (BMI) (P<0.01), tamoxifen taking (P=0.03), and no treatment interruption (P=0.03). No independent factor was associated with lung fibrosis under bolus-covered chest wall in multivariate analysis.

CONCLUSIONS

In the analysis of pulmonary fibrosis induced by unbolused electron beam, BMI rather than body weight and body height is a strong prognostic factor. Tamoxifen and short overall time can predispose the development of lung fibrosis.

Concomitant boost radiation therapy for inoperable non-small-cell lung cancer: preliminary report of a prospective randomized study

PURPOSE

The radiation therapy results for patients with inoperable non-small-cell lung cancer (NSCLC) have been disappointing. Tumor dose escalation using concomitant boost technique (CBT) has been shown to improve local control in a few prospective studies. This trial was carried out to prospectively assess the radiation response and acute toxicity of CBT in comparison to the conventional treatment technique (CTT).

METHODS AND MATERIALS

Ninety-seven consecutive eligible patients were entered in this prospective clinical trial between November 1994 and February 1998. Patients were randomized to receive either CBT (43 patients) or CTT (54 patients) radiation therapy. These patients either refused chemotherapy or were judged as unsuitable for chemotherapy. Patients in the CBT group received 46.8 Gy in 26 fractions using large fields that encompassed the gross and occult disease. A concomitant boost of 18.2 Gy (0.7 Gy per fraction) was delivered to the gross disease using small fields with 1.5-cm margins. The small fields were treated concurrently with the large fields and the total dose to the tumor area was 65 Gy in 26 fractions. Patients in the CTT group received 70.8 Gy in 38 fractions. The acute toxicity between each group was compared. The response rate was analyzed and compared by treatment group, gender, age, stage, histology, initial Karnofsky performance score (KPS), severity of acute toxicity, and maximum body weight loss (MBWL) during treatment course.

RESULTS

The demographic parameters such as sex, age, and stage were evenly distributed in each treatment group. The majority of these patients had Stage IIIA and IIIB disease. Overall median treatment times were 39 days for the CBT group of patients and 62 days for the CTT group. No treatment-related mortality was found. There were 2 patients in the CTT group with acute RTOG Grade 3 lung toxicity, and no Grade 3 lung or esophageal toxicity was observed in CBT group. The response rates, assessed by radiographic images, were 69.8% and 48.1% for the CBT and CTT patients, respectively. Univariate and multivariate analysis revealed that patients in the CBT group, patients with better KPS, and patients with more severe acute toxicity had a higher response rate.

CONCLUSION

This study demonstrates that concomitant boost radiation therapy is tolerable, and produces a superior response rate than conventional radiation therapy for patients with inoperable NSCLC. The length of treatment was reduced from 38 to 26 treatment days, almost a 30% reduction.

Oral glutamine to alleviate radiation-induced oral mucositis: a pilot randomized trial

PURPOSE

To evaluate the influence of oral glutamine on radiation-induced oral mucositis in the radiotherapy of head and neck cancer.

METHODS AND MATERIALS

From July 1997 through June 1998, 17 patients with head and neck cancer receiving primary or adjuvant irradiation were randomized to either glutamine suspension (16 g in 240 ml normal saline) (n = 8) or placebo (normal saline) (n = 9) arm. Patients were instructed to swish the test solutions (30 ml) four times per day. All patients received half-mouth irradiation at least. Patients were treated 1.8 Gy per fraction daily, 5 days a week. We evaluated the grading of oral mucositis daily fraction at each day of treatment until 45 Gy/25 fractions. World Health Organization (WHO) step analgesic medication and body weight change were compared between the two arms.

RESULTS

The duration of objective oral mucositis > or = Grade 1 (p = 0.0097), Grade 2 (p = 0.0232), and Grade 3 (p = 0.0168) was shorter in the glutamine arm. Mean maximum grade of objective oral mucositis was less severe in the glutamine arm (1.6 vs. 2.6) (p = 0.0058). Glutamine did not reduce the duration and severity of subjective oral mucositis except for duration > or = Grade 3 (p = 0.0386). In the analysis of mean maximum WHO step of analgesic medication, there was no statistical difference (p = 0.5374) between the two arms. Mean body weight change was also not significantly different (p = 0.8070).

CONCLUSIONS

Oral glutamine may significantly reduce the duration and severity of objective oral mucositis during radiotherapy. It may shorten the duration of > or = Grade 3 subjective mucositis.

Postoperative radiotherapy for supratentorial malignant gliomas

From January 1988 to December 1996, sixty-five patients with histologically confirmed supratentorial malignant gliomas were treated with postoperative radiation therapy in our department. They were subjected to this analysis according to different clinical and pathologic parameters. The overall 1-year, 2-year survival rate was 57% and 23%, respectively. With univariate analysis, age, postoperative Karnofsky performance status, duration of symptoms, multiplicity of lesions and the extent of surgery were identified as significant prognostic factors. With multivariate analysis, postoperative Karnofsky performance status and the extent of surgery continued to show independent prognostic significance on overall survival.

Radiation therapy in primary central nervous system lymphoma

BACKGROUND

Treatment of primary central nervous system lymphoma (PCNSL) in Chinese individuals has rarely been reported. Therefore, this article presents our experience in managing PCNSL with radiotherapy.

METHODS

A thorough review was made of the medical records of 13 patients diagnosed with PCNSL at Kaohsiung Chang Gung Memorial Hospital from 1988 through 1997. The clinical characteristics, treatment modalities, and results were analyzed as well.

RESULTS

Thirteen patients diagnosed with PCNSL were identified, of which 10 cases originated in the brain whereas three were of spinal origin. Seven of the patients were man and six were women, with a mean age of 54.9 +/- 13.1 years (range 29 to 74 years). Diffuse large cell lymphoma (11 cases) was the most common histology. Limb weakness (11 cases) and headache (7 cases) were the most common complaints at presentation. Nine patients received radiation therapy alone and four patients received radiation therapy plus chemotherapy after surgical resection or biopsy. Follow-up computed tomography (CT) scans 3 to 4 months after the completion of radiotherapy revealed that nine patients (69%) had a complete response and four (31%) had a partial response. Local recurrence occurred in five patients (56%) treated with radiation therapy alone and in one patient (25%) treated with combined modalities. The overall actuarial survival rate was 54% at 2 years and 27% at 5 years.

CONCLUSION

Results in this study indicate that the initial response to radiotherapy is satisfactory. However, a local relapse frequently occurs. Future considerations should focus on new modes of treatment, such as three-dimensional conformal radiation therapy for dose escalation or a combination of chemotherapy and radiotherapy.

Postoperative radiotherapy in early stage carcinoma of the uterine cervix: treatment results and prognostic factors

PURPOSE

The objective was to investigate the effect of pathologic parameters and other variables on treatment outcome for patients with International Federation of Gynecology and Obstetrics (FIGO) stage IB, IIA cervical carcinoma, as well as to assess the morbidities attributable to radical surgery combined with postoperative radiotherapy.

MATERIALS AND METHODS

Between January 1980 and June 1994, 179 women with FIGO stage IB, IIA carcinoma of the uterine cervix were treated with radical hysterectomy and postoperative irradiation. The median follow-up of alive patients was 6.8 years. All patients received 44-60 Gy external irradiation. One hundred fifty-nine patients received 3-10 Gy intracavitary brachytherapy. The data were analyzed for overall survival, disease-free survival, pelvic control, and treatment-related complications.

RESULTS

The 5-year overall survival rate, disease-free survival rate, and pelvic control rate for the 179 patients were 72, 74, and 90%, respectively. The 5-year overall survival rate was 81% for patients without pelvic lymphadenopathy and 53% for those with pelvic lymphadenopathy (P = 0.0000). Other independent prognostic factors for overall survival included tumor differentiation and the interval between operation and initiation of radiotherapy. For the endpoint of disease-free survival, pelvic lymph node status, tumor differentiation, the duration of interruption of radiotherapy, and the interval between operation and radiotherapy were of independent prognostic significance. As pelvic control was concerned, the 5-year pelvic control rate was 90% and only the duration of interruption of radiotherapy was noted as an independent predictor of pelvic control. Distant metastases were noted in 43 patients (24%); the most common sites were lung (10%), liver (6%), and bone (6%). The overall 5-year intestinal and urinary complication-free rate was 66 and 82%, respectively. The overall incidence of grade 3 or above late rectal and urinary sequelae was 10%. For patients sustaining leg lymphedema after radiotherapy, there was higher incidence of severe leg cellulitis which warranted antibiotics treatment.

CONCLUSION

These prognostic factors should be considered in patient counseling and treatment planning. Based on these factors, a more aggressive treatment to improve survival in these subsets of high-risk patients might be justified. New therapeutic regimens and modalities aimed to overcome treatment failure should be investigated.