Yee-Min Jen

Paediatric head CT scan and subsequent risk of malignancy and benign brain tumour: a nation-wide population-based cohort study.

Background:To evaluate the possible association between paediatric head computed tomography (CT) examination and increased subsequent risk of malignancy and benign brain tumour.Methods:In the exposed cohort, 24 418 participants under 18 years of age, who underwent head CT examination between 1998 and 2006, were identified from the Taiwan National Health Insurance Research Database (NHIRD). Patients were followed up until a diagnosis of malignant disease or benign brain tumour, withdrawal from the National Health Insurance (NHI) system, or at the end of 2008.Results:The overall risk was not significantly different in the two cohorts (incidence rate=36.72 per 100 000 person-years in the exposed cohort, 28.48 per 100 000 person-years in the unexposed cohort, hazard ratio (HR)=1.29, 95% confidence interval (CI)=0.90–1.85). The risk of benign brain tumour was significantly higher in the exposed cohort than in the unexposed cohort (HR=2.97, 95% CI=1.49–5.93). The frequency of CT examination showed strong correlation with the subsequent overall risk of malignancy and benign brain tumour.Conclusions:We found that paediatric head CT examination was associated with an increased incidence of benign brain tumour. A large-scale study with longer follow-up is necessary to confirm this result.

Squamous cell carcinoma of the buccal mucosa: An aggressive cancer requiring multimodality treatment

In our clinical practice, we have observed a high incidence of locoregional failure in squamous cell carcinoma (SCC) of the buccal mucosa. We analyze our treatment results of this cancer and compare these results with those in the literature. We intend to define the pattern and incidence of failure of buccal cancer and provide information for the design of a better multimodality treatment.

Etiology of Vocal Cord Paralysis

Objective: Vocal cord paralysis (VCP) is a sign of a certain underlying disease, a diagnosis which can be attributed to various causes. This study intends to analyze the contemporary etiology of VCP in a tertiary medical center. Materials and Methods: A retrospective review of medical records from June 2000 to December 2004 of hospitalized patients with VCP was done to determine the etiology. Results: Two hundred and ninety-one patients with a determined etiology were identified, consisting of 176 males and 115 females. Unilateral VCP was present in 259 patients, while 32 presented with bilateral VCP. The causes were surgical in 40.2%, neoplastic in 29.9%, idiopathic in 10.7%, traumatic in 8%, central in 3.8%, radiation-induced in 3.4%, inflammatory in 2%, cardiovascular in 1.7% and other causes in 0.3% of the cases. Thyroidectomy represented the most common surgery for VCP and was the cause in 57 patients. Lung cancer was responsible for 34 cases and was the most common neoplastic etiology. In males, neoplasm was the most common cause occurring in 63 of 176 males, whereas surgery was most frequent in 59 of 115 females. Conclusion: Surgical trauma, mainly thyroidectomy, is the most common cause of VCP in hospitalized patients. The possibility of a neoplasm must be ruled out before VCP is labeled idiopathic. A benign thyroid tumor could also cause VCP. Besides, radiation-induced cranial nerve paralysis in head and neck cancer may play a significant role.

DOSE ESCALATION USING TWICE-DAILY RADIOTHERAPY FOR NASOPHARYNGEAL CARCINOMA: DOES HEAVIER DOSING RESULT IN A HAPPIER ENDING?

PURPOSE To present our experience using a twice-daily radiotherapy (RT) technique, including hyperfractionated and accelerated-hyperfractionated RT, on nasopharyngeal carcinoma (NPC) patients. The dose to the primary tumor was increased in the hope that local control could be increased without the cost of increased late complications. We analyzed acute and late complications and local control and compared the results with the results of NPC patients treated during the same period using conventional once-daily RT. METHODS AND MATERIALS Between October 1991 and July 1998, 222 histologically confirmed, Stage M0, previously unirradiated NPC patients completed RT at our hospital. Most patients had American Joint Committee on Cancer (AJCC) 1992 Stage III and IV disease. Among them, 88 received altered fractionated, twice-daily RT; 76 patients received hyperfractionated RT and 12 accelerated-hyperfractionated RT. The remaining 134 patients received a conventional once-daily regimen. Hyperfractionated RT was delivered using 120 cGy b.i.d. separated by 6-h intervals throughout the course. For the accelerated-hyperfractionated patients, 160 cGy b.i.d. was given, also at 6-h intervals. The median dose in the twice-daily group was 7810 cGy (range 6840-8200). In the once-daily regimen, RT was delivered using 180-200 cGy q.d. The median tumor dose to the primary tumor was 7000 cGy (range 6560-8100) given during about 8 weeks. The median follow-up time was 70.5 and 72 months for the twice-daily and once-daily groups, respectively. RESULTS The incidence of acute toxicities was higher in the twice-daily group with more severe mucositis and moist desquamation than in the once-daily group. Both groups had a similar incidence of late complications, except for 3 cases of temporal lobe necrosis in the twice-daily group, all in patients treated with 160 cGy. No difference was noted in recurrence-free local control between the two groups when the individual T stage was compared using AJCC 1992 or 1997 criteria (p = 0.51 and 0.59, respectively). The 5-year local control rate for T1-3 (AJCC 1997) was 93.2% for the twice-daily group and 86.4% for the once-daily group (p = 0.45). In Stage T4 (AJCC 1997) patients, the local control rate dropped drastically to 43.5% and 36.9% for the twice-daily and once-daily groups, respectively. The overall neck control rate at 5 years was 87.3% and 80.3% for the twice-daily and once-daily patients, respectively (p = 0.16). The overall locoregional control rate was 82.7% for the twice-daily group and 66.6% for the once-daily group. The difference was again not statistically significant, but showed a tendency in favor of the twice-daily regimen (p = 0.055). Locoregional failure occurred mainly in Stage T4 patients with central nervous invasion for whom local control was particularly poor, with a failure rate of about 60%. CONCLUSION The present data suggest that NPC patients can be safely treated using a 120-cGy twice-daily program with a 6-h interval up to 8000 cGy. The accelerated-hyperfractionated technique is not recommended. A large discrepancy in local control between patients with T1-3 and T4 disease was noted. For T1-3 disease, an excellent local control rate >90% was achieved using the twice-daily regimen. In contrast, failure in the T4 patients was as high as 55% in the twice-daily group and reached 65% in the once-daily group. More rigorous treatment is needed using either additional dose escalation or other strategies for T4 NPC patients. With a dose escalation of 1000 cGy using 120-cGy twice-daily RT, a trend toward better locoregional control and disease-specific survival was noted in the twice-daily group. Whether this difference was truly the result of an increased dose needs additional confirmation in studies with larger patient numbers.

Ruptured internal carotid pseudoaneurysm in a nasopharyngeal carcinoma patient with skull base osteoradionecrosis

Nasopharyngeal carcinoma (NPC) is a major head and neck cancer with a relatively high incidence of about 5.4 per 100,000 persons in Taiwan. The primary treatment of NPC has been external radiotherapy (RT). Now with combined chemotherapy and intracavity brachytherapy, more patients enjoy a longer survival. However, radiation-induced morbidity, including xerostomia, chronic otitis media, chronic paranasal sinusitis, temporal lobe necrosis, cranial neuropathy, carotid stenosis, palatal perforation, and brainstem damage, increases with more aggressive treatment. The development of skull base osteoradionecrosis (ORN) has been reported. Rupture of irradiated great vessels is an uncommon complication, and it tends to occur in the carotid artery in patients with cancer of the head and neck. Sudden and massive hemorrhage is usually unexpected and fatal, particularly when it occurs in the nasopharynx, and it is one of the most dreaded post-RT complications among NPC patients. We describe the first published and successfully managed report of a case involving skull base ORN with a ruptured internal carotid pseudoaneurysm (PA) in NPC after irradiation.

Intensity modulated radiotherapy with concurrent chemotherapy for larynx preservation of advanced resectable hypopharyngeal cancer

BackgroundTo analyze the rate of larynx preservation in patients of locally advanced hypopharyngeal cancer treated with intensity modulated radiotherapy (IMRT) plus concurrent chemotherapy, and compare the results with patients treated with primary surgery.MethodsBetween January 2003 and November 2007, 14 patients were treated with primary surgery and 33 patients were treated with concurrent chemoradiotherapy (CCRT) using IMRT technique. Survival rate, larynx preservation rate were calculated with the Kaplan-Meier method. Multivariate analysis was conducted for significant prognostic factors with Cox-regression method.ResultsThe median follow-up was 19.4 months for all patients, and 25.8 months for those alive. The 5-year overall survival rate was 33% and 44% for primary surgery and definitive CCRT, respectively (p = 0.788). The 5-year functional larynx-preservation survival after IMRT was 40%. Acute toxicities were common, but usually tolerable. The rates of treatment-related mucositis (≥ grade 2) and pharyngitis (≥ grade 3) were higher in the CCRT group. For multivariate analysis, treatment response and cricoid cartilage invasion strongly correlated with survival.ConclusionsIMRT plus concurrent chemotherapy may preserve the larynx without compromising survival. Further studies on new effective therapeutic agents are essential.

TWICE-PER-DAY FRACTIONATED HIGH VERSUS CONTINUOUS LOW DOSE RATE INTRACAVITARY THERAPY IN THE RADICAL TREATMENT OF CERVICAL CANCER: A NONRANDOMIZED COMPARISON OF TREATMENT RESULTS

PURPOSE To compare the efficacy of two twice-per-day fractionated high dose rate (HDR) brachytherapies with a historical control group treated with low dose rate (LDR) brachytherapy for cervical cancer patients. METHODS AND MATERIALS From 1985 to 1988, 92 patients with cancer of the cervic were treated by remote-controlled, HDR brachytherapy, six fractions of 7 Gy per fraction (42 Gy) at point A (HDR-6). Fifty-seven patients were treated with four fractions of 8 Gy per fraction (32 Gy) at point A (HDR-4). A twice-per-day program was used for all HDR patients by two split courses. As a historical control, treatment results of 259 patients treated with LDR brachytherapy (40 Gy in two split courses) were compared with those of the two HDR regimens. All patients received whole pelvic external irradiation, 36-45 Gy (mostly 40 Gy) before brachytherapy. RESULTS Five-year local control rates were not significantly different for the three groups (HDR-6 = 82.0%, HDR-4 = 85.5%, and LDR = 89.5%, respectively). Five-year survival rates were also comparable (67.7%, 77.9%, and 74.1%, respectively). However, late complications were lower in HDR-4 than HDR-6 (11.0% vs. 25.6%). CONCLUSIONS Both 5-year local control and survival rates were comparable among the three groups. However, HDR-4, which was more biologically equivalent to our LDR regimen, showed fewer complications compared to HDR-6. In addition, our twice-per-day schedule shortened the hospital stay.

18F-FDG PET and Combined 18F-FDG–Contrast CT Parameters as Predictors of Tumor Control for Hepatocellular Carcinoma After Stereotactic Ablative Radiotherapy

The application of stereotactic ablative radiotherapy (SABR) to hepatocellular carcinoma (HCC) is emerging. To identify pretreatment prognostic indicators is crucial for patient selection and optimal individual therapy. The aim of this study was to determine whether 18F-FDG PET and a combined 18F-FDG–contrast CT parameter could be useful tools to predict tumor control for patients with HCC treated by SABR. Methods: We retrospectively identified 31 patients (41 tumors) who underwent 18F-FDG PET before SABR between November 2007 and September 2011. 18F-FDG PET parameters were collected as prognostic indicators, including visual PET scale (+/−), maximal standardized uptake value (SUV) of the tumor (TSUVmax), ratio of TSUVmax to maximal normal-liver SUV, ratio of TSUVmax to mean normal-liver SUV, and score combining tumor volume and TSUVmax (CT/18F-FDG PET score). They underwent SABR with a median dose of 42 Gy (ranging from 30 to 50 Gy) in 4–5 fractions. 18F-FDG PET parameters and clinical factors were tested as predictors of tumor control and patient survival. Results: The median follow-up time was 18 mo. Among the parameters examined, TSUVmax and CT/18F-FDG PET score were significantly correlated with tumor control. TSUVmax with a cutoff value of 3.2 was the most significant prognostic indicator. The 4-y control rate was 86.2% in tumors with a TSUVmax of 3.2 or less but only 37.5% in those with a TSUVmax of more than 3.2 (adjusted hazard ratio, 9.40; 95% confidence interval, 1.18–74.76; P = 0.034). CT/18F-FDG PET score (≤4 vs. >4) was also a significant predictor of tumor control after SABR. Tumors with a CT/18F-FDG PET score of more than 4 had a 5.23-fold risk of tumor failure. After adjustment for factors of sex, American Joint Committee on Cancer stage, Cancer of the Liver Italian Program score, and Child–Pugh classification, tumors with a score of more than 4 had a 4.96-fold risk of failure after SABR, compared with tumors with a score of 4 or less. For overall survival, none was statistically significant. Conclusion: The use of 18F FDG PET to predict tumor control is feasible. TSUVmax with a cutoff value of 3.2 is the best prognostic indicator. We suggest that 18F-FDG PET may be a reference for prognostic prediction, patient selection, and radiation dose adjustment for HCC patients treated with SABR.

Stereotactic ablative radiotherapy for unresectable hepatocellular carcinoma patients who failed or were unsuitable for transarterial chemoembolization.

Background The role of stereotactic ablative radiotherapy (SABR) in patients with hepatocellular carcinoma (HCC) who are refractory to or unsuitable for transarterial chemoembolization remains unclear. We examined the efficacy and safety of Cyberknife SABR and its effect on survival in this group of HCC patients. Materials and methods From June 2008 to June 2011, 53 patients with 68 tumors of unresectable HCC were treated using Cyberknife SABR. The tumors measured 1.1–13 cm (median, 4.3 cm). The median prescribed dose was 40 Gy in four to five fractions over 4–5 consecutive working days. Results The median follow-up period was 13.1 months for all patients and 18.1 months for the living patients. Objective responses were observed in 48 of 67 tumors (71.6%), including 22 tumors (32.8%) with complete responses. The 1- and 2-year in-field failure-free rate was 73.3 and 66.8%, respectively. Out-field intrahepatic recurrence was the main cause of treatment failure (28/52 patients). The median survival time was 20.0 months, and the 1- and 2-year overall survival rate was 70.1 and 45.4%, respectively. Multivariable analysis showed that Eastern Cooperative Oncology Group performance status (⩽1 vs. >1) and tumor response (responder vs. nonresponder) were independent prognostic factors for overall survival. Radiation-induced liver disease, including classic and nonclassic types, developed in five patients (9.4%). Other acute toxicities were generally mild and tolerable. Conclusion Our findings supported the feasibility of SABR as a salvage treatment for HCC when transarterial chemoembolization was ineffective or technically unsuitable. Additional efforts to improve the response rate and reduce out-field recurrence are required.

Dosimetric and efficiency comparison of high‐dose radiotherapy for esophageal cancer: volumetric modulated arc therapy versus fixed‐field intensity‐modulated radiotherapy

The aim of this study was to compare high-dose volumetric modulated arc therapy (VMAT) and fixed-field intensity-modulated radiotherapy (ff-IMRT) plans for the treatment of patients with middle-thoracic esophageal cancer. Eight patients with cT2-3N0M0 middle-thoracic esophageal cancer were enrolled. The treatment planning system was the version 9 of the Pinnacle(3) with SmartArc (Philips Healthcare, Fitchburg, WI, USA). VMAT and ff-IMRT treatment plans were generated for each case, and both techniques were used to deliver 50 Gy to the planning target volume (PTV(50)) and then provided a 16-Gy boost (PTV(66)). The VMAT plans provided superior PTV(66) coverage compared with the ff-IMRT plans (P = 0.034), whereas the ff-IMRT plans provided more appropriate dose homogeneity to the PTV(50) (P = 0.017). In the lung, the V(5) and V(10) were lower for the ff-IMRT plans than for the VMAT plans, whereas the V(20) was lower for the VMAT plans. The delivery time was significantly shorter for the VMAT plans than for the ff-IMRT plans (P = 0.012). In addition, the VMAT plans delivered fewer monitor units. The VMAT technique required a shorter planning time than the ff-IMRT technique (3.8 ± 0.8 hours vs. 5.4 ± 0.6 hours, P = 0.011). The major advantages of VMAT plans are higher efficiency and an approximately 50% reduction in delivery time compared with the ff-IMRT plans, with comparable plan quality. Further clinical investigations to evaluate the use of high-dose VMAT for the treatment of esophageal cancer are warranted.