Tumor volume and local control in primary radiotherapy of nasopharyngeal carcinoma

DW-MRI-Guided Dose Escalation Improves Local Control of Locally Advanced Nasopharyngeal Carcinoma Treated with Chemoradiotherapy

Background

Nasopharyngeal carcinoma (NPC) is one of the most highly radiosensitive malignancies; however, some locally advanced NPC patients experienced local recurrence even though they received aggressive treatment regimens. Defining the tumor volume precisely is important to escalate the total dose required for the primary tumor. In this study, we aimed to investigate the feasibility and efficacy of dose escalation guided by DW-MRI in patients with locally advanced NPC.

Patients and Methods

A total of 230 patients with locally advanced NPC treated with intensive modulated radiotherapy (IMRT) at Sichuan Cancer Hospital between January 2010 and January 2015 were enrolled in this retrospective study. All the patients were treated with all-course of simultaneous integrated boost-IMRT. DW-MRI-guided dose escalation with 2.2–2.5 Gy/F, qd for 1–3 days or 1.2–1.5 Gy/F, bid for 1–3 days were prescribed to 123 patients. Survival and complication of the patients were evaluated, and multivariate analysis was performed.

Results

The median follow-up of patients in the DW-MRI-guided dose-escalation group and the conventional group was 48 months (range 8–88 months) and 52 months (range 6–90 months), respectively. The 5-year overall survival rate, distant metastasis-free survival rate, progression-free survival, and local recurrence-free survival (LRFS) of patients in the dose-escalation group and the conventional group were 88% vs 82.5% (p = 0.244), 86.1% vs 83.3% (p = 0.741), 82.2% vs 76.6% (p = 0.286), and 89.1% vs 80.1% (p = 0.029), respectively. Multivariate analysis showed that dose escalation was independent prognostic factor for LRFS (HR 0.386, 95% CI 0.163–0.909, p = 0.03).

Conclusion

DW-MRI-guided dose escalation is a feasible strategy to improve local control of patients with locally advanced NPC. The treatment-related complications are tolerable.

Effect of relevant factors on radiation-induced nasopharyngeal ulcer in patients with primary nasopharyngeal carcinoma treated with intensity-modulated radiation therapy

OBJECTIVE

To analyze the correlation between relevant factors and radiation-induced nasopharyngeal ulcer (RINU) in primary nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT).

METHODS

Clinical data were collected for 599 patients with newly diagnosed NPC who had completed IMRT. The entire cohort was randomly divided into two subgroups. The relationship between RINU and IMRT dose-volume were statistically analyzed with ROC curves and the Chi-square test. Nutritional status during and after treatment was compared between patients with vs without RINU.

RESULTS

The results obtained showed that dose-volume had no effect on the incidence of RINU (P > .05). Nutrition-related parameters differed significantly between patients with vs without RINU (P < .05).

CONCLUSION

The results obtained show that the incidence of RINU is not related to IMRT dose-volume in the treatment of primary NPC. The incidence of RINU was found to be related to nutritional status during and after radiation therapy.

LEVEL OF EVIDENCE

2a.

Metabolic tumor volume and conformal radiotherapy based on prognostic PET/CT for treatment of nasopharyngeal carcinoma

For patients with nasopharyngeal carcinoma (NPC), prognostic indicators to customize subsequent biologically conformal radiation therapy may be obtained via 2-(fluorine-18)-fluoro-2-deoxy-D-glucose (F-FDG) positron emission tomography/computed tomography (PET/CT). This retrospective study assessed the prognostic significance and feasibility of conformal radiotherapy for NPC, based on F-FDG PET/CT. Eighty-two patients with NPC underwent F-FDG PET/CT prior to intensity-modulated radiation therapy (IMRT). The maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) of the primary tumor were measured, with MTVx based on absolute SUVx values ≥ specific threshold x on each axial image. The cut-off SUVmax and MTV values for predicting 3-year progression-free survival (PFS) were calculated according to a receiver operating characteristic curve. Assessed were correlations between SUVmax and MTV and between threshold x and MTVx, and the MTV percentage of the primary tumor volume at threshold x. The SUVmax and MTV were positively associated, as were MTV and primary tumor volume. Primary tumor volume, SUVmax, and MTV were significant predictors of survival. The 3-year PFS rates for SUVmax ≤8.20 and >8.20 were 91.1% and 73.0%, respectively (P = .027). With furthermore analysis, patients having tumor with smaller MTV had higher 3-year PFS than patients having tumor with larger MTV. The 3-year PFS rate was inversely related to MTV. SUVmax and MTV, derived by PET/CT, are important for assessing prognosis and planning radiotherapy for patients with NPC. Small MTV indicated better 3-year PFS compared with large MTV. For the best therapeutic effect, MTV4.0 was the best subvolume to determine radiotherapy boost.

The impact of the time to start radiation therapy on overall survival in newly diagnosed glioblastoma

PURPOSE

The standard treatment for newly diagnosed glioblastoma includes maximal safe surgical resection followed by concurrent radiation therapy and temozolomide (TMZ) and maintenance TMZ. The impact of time to start radiation therapy (TRT) on overall survival (OS) in glioblastoma patients is controversial. The study aimed to evaluate the impact of TRT on OS in patients diagnosed with glioblastoma who received standard treatment.

METHODS

In this retrospective study, we included patients with confirmed diagnosis of glioblastoma treated from 2011 to 2016. TRT was defined as the time between surgery (biopsy or resection) and the first day of radiation therapy. The endpoint was OS. The patients were divided according to the TRT in three categories: < 30 days, 30-60 days and ≥ 60 days.

RESULTS

A total of 134 patients were included with a mean age of 51.82 years (range 19-78 years). Median TRT was 80 days. On univariate and multivariable analysis, we identified age as the only significant independent predictor for OS. There was no statistically significant negative impact of TRT on OS (p = 0.47).

CONCLUSIONS

There was no clear evidence that delaying post-operative combined chemoradiotherapy negatively impacts OS, not even for TRT longer than 60 days.

Evaluation of Volume of Nasopharyngeal Cancers by the Cavalieri Principle

Prediction of tumor volume using the Cavalieri method may be helpful in management of therapy and evaluation of treatment results. The aim of this study was to adapt the Cavalieri stereological method to magnetic resonance imaging for determining volume of nasopharyngeal cancers and assess changes after treatment using the Cavalieri method. Serial MRI images in the sagittal plane were obtained from a total of 33 patients with nasopharyngeal carcinomas (11 with stage T2, 11 with stage T3, and 11 with stage T4 lesions). The images were analyzed retrospectively before and two months following the cessation of radiochemotherapy for comparison. Average tumor volumes before and after treatment in patients with stage T2 were 21. 5±10.5 cm3 and 2.82±3.43 cm³, respectively (p=0.000). The respective figures were 35.1±19.0 cm3 and 6.27±7.82 cm³ (p=0.000) for stage T3 cases, and 62.8±27.8 cm3 and 11. 6±11.9 cm3 (p=0.000) for stage T4. Post-treatment tumor volumes were statistically reduced when compared to pre-treatment volumes in all stages.

Standardized tumor volume: an independent prognostic factor in advanced nasopharyngeal carcinoma

The study evaluated the prognostic effect of standardized tumor volume in patients with advanced nasopharyngeal carcinoma (NPC) treated with concurrent chemoradiotherapy. Between Jan 1, 2009 and December 30, 2012, 143 patients diagnosed with NPC in UICC stage III–IVb by histopathology were enrolled in the study. These patients underwent intensity-modulated radiotherapy combined with concurrent chemotherapy. The three-dimensional images of tumor volume were reconstructed automatically by the treatment planning system. SGTVnx was calculated based on GTVnx/person’s volume. SGTVnd was calculated based on GTVnd/person’s volume. SGTVnx was significantly associated with the 5-year overall survival (OS), disease-free survival (DFS), DMFS, and LRFS rates in univariate and multivariate analyses. Although SGTVnd was associated with the 5-year OS, DFS, and DMFS rates, it was not an independent prognostic factor for LRFS. In receiver operating characteristic (ROC) curve analysis, 1.091 and 0.273 were determined as the cut-off points for SGTVnx and SGTVnd, respectively. The 5-year OS, DFS, DMFS, and LRFS rates for patients with a SGTVnx > 1.091 vs. SGTVnx ≤ 1.091 was 65.4% vs. 93.4% (P < 0.001), 65.2% vs. 94.8% (P < 0.001), 71.4% vs. 97.4% (P < 0.001), and 84.8% vs. 97.3% (P = 0.003), respectively, for SGTVnd > 0.273 vs. SGTVnd ≤ 0.273 was 70.3% vs. 96.5% (P < 0.001), 70.1% vs. 94.8% (P < 0.001), 77.5% vs. 98.2% (P < 0.001), and 88.5% vs. 96.6% (P = 0.049), respectively. UICC stage grouping, T classification, N classification, and sex were not found to be independent prognostic factors for NPC. Standardized tumor volume was an independent prognostic factor for NPC that might improve the current NPC TNM classification system and provide new clinical evidence for personalized treatment strategies.

Modeling tumor control probability for spatially inhomogeneous risk of failure based on clinical outcome data

PURPOSE

Objectives of this work are (1) to derive a general clinically relevant approach to model tumor control probability (TCP) for spatially variable risk of failure and (2) to demonstrate its applicability by estimating TCP for patients planned for photon and proton irradiation.

METHODS AND MATERIALS

The approach divides the target volume into sub-volumes according to retrospectively observed spatial failure patterns. The product of all sub-volume TCP_i values reproduces the observed TCP for the total tumor. The derived formalism provides for each target sub-volume i the tumor control dose (D_50,i) and slope (γ_50,i) parameters at 50% TCP_i. For a simultaneous integrated boost (SIB) prescription for 45 advanced head and neck cancer patients, TCP values for photon and proton irradiation were calculated and compared. The target volume was divided into gross tumor volume (GTV), surrounding clinical target volume (CTV), and elective CTV (CTVE). The risk of a local failure in each of these sub-volumes was taken from the literature.

RESULTS

Convenient expressions for D_50,i and γ_50,i were provided for the Poisson and the logistic model. Comparable TCP estimates were obtained for photon and proton plans of the 45 patients using the sub-volume model, despite notably higher dose levels (on average +4.9%) in the low-risk CTVE for photon irradiation. In contrast, assuming a homogeneous dose response in the entire target volume resulted in TCP estimates contradicting clinical experience (the highest failure rate in the low-risk CTVE) and differing substantially between photon and proton irradiation.

CONCLUSIONS

The presented method is of practical value for three reasons: It (a) is based on empirical clinical outcome data; (b) can be applied to non-uniform dose prescriptions as well as different tumor entities and dose-response models; and (c) is provided in a convenient compact form. The approach may be utilized to target spatial patterns of local failures observed in patient cohorts by prescribing different doses to different target regions. Its predictive power depends on the uncertainty of the employed established TCP parameters D₅₀ and γ₅₀ and to a smaller extent on that of the clinically observed pattern of failure risk.

Prognostic value and predictive threshold of tumor volume for patients with locally advanced nasopharyngeal carcinoma receiving intensity-modulated radiotherapy

Background

Gross target volume of primary tumor (GTV-P) is very important for the prognosis prediction of patients with nasopharyngeal carcinoma (NPC), but it is unknown whether the same is true for locally advanced NPC patients treated with intensity-modulated radiotherapy (IMRT). This study aimed to clarify the prognostic value of tumor volume for patient with locally advanced NPC receiving IMRT and to find a suitable cut-off value of GTV-P for prognosis prediction.

Methods

Clinical data of 358 patients with locally advanced NPC who received IMRT were reviewed. Receiver operating characteristic (ROC) curves were used to identify the cut-off values of GTV-P for the prediction of different endpoints [overall survival (OS), local relapse-free survival (LRFS), distant metastasis-free survival (DMFS), and disease-free survival (DFS)] and to test the prognostic value of GTV-P when compared with that of the American Joint Committee on Cancer T staging system.

Results

The 358 patients with locally advanced NPC were divided into two groups by the cut-off value of GTV-P as determined using ROC curves: 219 (61.2%) patients with GTV-P ≤46.4 mL and 139 (38.8%) with GTV-P >46.4 mL. The 3-year OS, LRFS, DMFS, and DFS rates were all higher in patients with GTV-P ≤46.4 mL than in those with GTV-P > 46.4 mL (all P < 0.05). Multivariate analysis indicated that GTV-P >46.4 mL was an independent unfavorable prognostic factor for patient survival. The ROC curve verified that the predictive ability of GTV-P was superior to that of T category (P < 0.001). The cut-off values of GTV-P for the prediction of OS, LRFS, DMFS, and DFS were 46.4, 57.9, 75.4 and 46.4 mL, respectively.

Conclusion

In patients with locally advanced NPC, GTV-P >46.4 mL is an independent unfavorable prognostic indicator for survival after IMRT, with a prognostic value superior to that of T category.

The influence of human papillomavirus on nasopharyngeal carcinoma in Japan

OBJECTIVE

Although Japan is a non-endemic area with nasopharyngeal carcinoma (NPC), the proportion of WHO type I NPC in Japan are different from that in non-endemic areas such as North America and Europe. Recently, it is said that not only Epstein-Barr virus (EBV) but also human papillomavirus (HPV) has an influence on NPC in non-endemic areas. The aim of this study is to clarify the influence of HPV on NPC in Japan.

METHODS

Paraffin-embedded tumor specimens were available for 59 patients with NPC diagnosed between 1996 and 2015. We detected the virus status by p16 immunohistochemistry, HPV PCR, and in situ hybridization for Epstein-Barr virus (EBV)-encoded RNA. Kaplan-Meier curves were used to compare the overall survival by viral status.

RESULTS

Among the 59 patients, 49 (83%) were EBV-positive/HPV-negative, 2 (3%) were EBV-positive/HPV-positive, and 8 (16%) were EBV-negative/HPV-negative. All HPV-positive NPCs were co-infected with EBV. There were no significant differences between the overall survival in the three groups (p=0.111).

CONCLUSION

In Japan, HPV was detected in a few patients with NPC, and we suggest that HPV has no influence on NPC carcinogenesis in this population.

Prognostic nomogram for refining the prognostication of the proposed 8th edition of the AJCC/UICC staging system for nasopharyngeal cancer in the era of intensity-modulated radiotherapy

BACKGROUND

The objective of this study was to develop a nomogram for refining prognostication for patients with nondisseminated nasopharyngeal cancer (NPC) staged with the proposed 8th edition of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) staging system.

METHODS

Consecutive patients who had been investigated with magnetic resonance imaging, staged with the proposed 8th edition of the AJCC/UICC staging system, and irradiated with intensity-modulated radiotherapy from June 2005 to December 2010 were analyzed. A cohort of 1197 patients treated at Fujian Provincial Cancer Hospital was used as the training set, and the results were validated with 412 patients from Pamela Youde Nethersole Eastern Hospital. Cox regression analyses were performed to identify significant prognostic factors for developing a nomogram to predict overall survival (OS). The discriminative ability was assessed with the concordance index (c-index). A recursive partitioning algorithm was applied to the survival scores of the combined set to categorize the patients into 3 risk groups.

RESULTS

A multivariate analysis showed that age, gross primary tumor volume, and lactate dehydrogenase were independent prognostic factors for OS in addition to the stage group. The OS nomogram based on all these factors had a statistically higher bias-corrected c-index than prognostication based on the stage group alone (0.712 vs 0.622, P <.01). These results were consistent for both the training cohort and the validation cohort. Patients with <135 points were categorized as low-risk, patients with 135 to <160 points were categorized as intermediate-risk, and patients with ≥160 points were categorized as high-risk. Their 5-year OS rates were 92%, 84%, and 58%, respectively.

CONCLUSIONS

The proposed nomogram could improve prognostication in comparison with the TNM stage group. This could aid in risk stratification for individual NPC patients. Cancer 2016;122:3307-3315. © 2016 American Cancer Society.

Prognostic value of the distance between the primary tumor and brainstem in the patients with locally advanced nasopharyngeal carcinoma

BACKGROUND

Brainstem dose limitations influence radiation dose reaching to tumor in the patients with locally-advanced nasopharyngeal cancer (NPC).

METHODS

A retrospective analysis of the prognostic value of the distance between the primary tumor and brainstem (Dbs) in 358 patients with locally-advanced NPC after intensity-modulated radiation therapy (IMRT). Receiver operating characteristic (ROC) curves were used to identify the cut-off value to analyze the impact of Dbs on tumor dose coverage and prognosis.

RESULTS

The three-year overall survival (OS), local relapse-free survival (LRFS), distant metastasis-free survival (DMFS), and disease-free survival (DFS) were 88.8 vs. 78.4% (P = 0.007), 96.5 vs. 91.1% (P = 0.018), 87.8 vs. 79.3% (P = 0.067), and 84.1 vs. 69.6% (P = 0.002) for the patients with the Dbs > 4.7 vs. ≤ 4.7 mm, respectively. ROC curves revealed Dbs (4.7 mm) combined with American Joint Committee on Cancer (AJCC) T classification had a significantly better prognostic value for OS (P < 0.05).

CONCLUSIONS

Dbs (≤ 4.7 mm) is an independent negative prognostic factor for OS/LRFS/DFS and enhances the prognostic value of T classification in the patients with locally-advanced NPC.

Relationships between Tumor Volume and Lymphatic Metastasis and Prognosis in Early Oral Tongue Cancer

Objectives

Although T stage is an important prognostic tool for oral tongue cancer, it fails to define the depth of invasion and true three-dimensional volume of primary tumors. The purpose of this paper is to determine the relations between tumor volume and lymph node metastasis and survival in early oral tongue cancer.

Methods

Forty-seven patients with T1-2 tongue cancer were included. Tumor volumes were measured by the computerized segmentation of T2-weighted magnetic resonance imaging.

Results

The overall average tumor volume was 27.7 cm³ (range, 1.4 to 60.1 cm³). A significant positive correlation was found between tumor volume and pathological T stage, depth of invasion, and cervical lymph node metastasis (P<0.001, P<0.001, and P=0.002, respectively). When the tumor volume exceeded 20 cm³, the cervical metastasis rate increased to 69.2%. The overall 5-year disease specific survival rate was 80%. There was a statistically significant association between large tumor volume (≥20 cm³) and the 5-year disease-specific survival (P=0.046).

Conclusion

Tumor volume larger than 20 cm³ was associated with greater risk cervical lymph node metastasis and poor 5-year disease-specific survival rate in early oral tongue cancer patients.

Prognostic value of tumor volume for patients with nasopharyngeal carcinoma treated with concurrent chemotherapy and intensity-modulated radiotherapy

PURPOSE

We aimed to analyze prognostic factors in patients with nasopharyngeal carcinoma (NPC) treated with concurrent chemotherapy and intensity-modulated radiotherapy (IMRT); in addition, we aimed to elucidate the value of primary gross tumor volume (GTVp) in predicting prognosis of patients.

METHODS

Between February 2001 and December 2008, 321 patients with NPC treated with concurrent chemotherapy and IMRT were analyzed retrospectively. GTVp was calculated from treatment planning computed tomography scans. A receiver operating characteristics (ROC) curve was used to determine the best cutoff point of GTVp.

RESULTS

The 5-year local failure-free survival (LFFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) for NPC patients were 93.8, 80.1, 73.0, and 83.7 %, respectively. Univariate and multivariate analyses indicated that GTVp had exhibited a statistically significant correlation with LFFS, DMFS, DFS, and OS (P < 0.05, all), whereas T classification was not an independent prognostic factor. According to ROC curve analysis, 49 and 19 mL were determined as the cutoff points of GTVp for local control and distant metastasis, respectively. Based on this, 321 patients were divided into three volume subgroups. LFFS, DMFS, DFS, and OS demonstrated significant differences among patients in different volume subgroups (P < 0.001, all) and were superior to T classification for predicting prognosis of NPC patients.

CONCLUSIONS

Primary gross tumor volume is an independent prognostic factor in local control, distant metastasis, disease-free survival, and overall survival in NPC. An adjusted TNM staging system that includes GTVp as a quantitative indicator to evaluate prognosis is warranted.

Staging of nasopharyngeal carcinoma--the past, the present and the future

This article reviews the evolution of the International Union Against Cancer/American Joint Committee on Cancer staging system for nasopharyngeal carcinoma. With the increasing availability of newer imaging methods, more sophisticated radiotherapy techniques and rapidly evolving molecular assays, we also examine newer clinical features that might have impact on staging. A new version of the staging system taking into account of some of these factors is also proposed.

Prognostic significance of maximum primary tumor diameter in nasopharyngeal carcinoma

Background

To evaluate the prognostic value of maximum primary tumor diameter (MPTD) in nasopharyngeal carcinoma (NPC).

Methods

Three hundred and thirty-three consecutive, newly-diagnosed NPC patients were retrospectively reviewed. Kaplan-Meier analysis and the log-rank test were used to estimate overall survival (OS), failure-free survival (FFS), distant metastasis-free survival (DMFS) and local relapse-free survival (LRFS). Cox proportional hazards regression analysis was used to assess the prognostic value of MPTD.

Results

Median follow-up was 66 months (range, 2–82 months). Median MPTD in stage T1, T2, T3 and T4 was 27.9, 37.5, 45.0 and 61.3 mm, respectively. The proportion of T1 patients with a MPTD ≤ 30 mm was 62.3%; 72% and 62.9% of T2 and T3 patients had a MPTD > 30–50 mm, and 83.5% of T4 patients had a MPTD > 50 mm. For patients with a MPTD ≤ 30 mm, > 30–50 mm and > 50 mm, the 5-year OS, FFS, DMFS and LRFS rates were 85.2%, 74.2% and 56.3% (P < 0.001); 87%, 80.7% and 62.8% (P < 0.001); 88.7%, 86.4% and 72.5% (P = 0.003); and 98.2%, 93.2% and 86.3% (P = 0.012), respectively. In multivariate analysis, MPTD was a prognostic factor for OS, FFS and DMFS, and the only independent prognostic factor for LRFS. For T3-T4 patients with a MPTD ≤ 50 mm and > 50 mm, the 5-year OS, FFS and DMFS rates were 70.4% vs. 58.4% (P = 0.010), 77.5% vs. 65.2% (P = 0.013) and 83.6% vs. 73.6% (P = 0.047), respectively. In patients with a MPTD ≤ 30 mm, 5-year LRFS in T1, T2, T3 and T4 was 100%, 100%, 88.9% and 100% (P = 0.172).

Conclusions

Our data suggest that MPTD is an independent prognostic factor in NPC, and incorporation of MPTD might lead to a further refinement of T staging.

Prognostic significance of tumor volume in patients with nasopharyngeal carcinoma undergoing intensity-modulated radiation therapy

BACKGROUND

This study was undertaken to analyze the correlation between primary gross tumor volume (GTVp) and prognosis in patients with nasopharyngeal carcinoma (NPC) undergoing intensity-modulated radiation therapy (IMRT).

METHODS

Between February 2001 and December 2006, 305 patients with NPC treated with IMRT were analyzed retrospectively. GTVp was calculated from treatment planning CT scans.

RESULTS

Univariate and multivariate analyses indicated that GTVp had a statistically significant correlation to local control, distant metastasis, and overall survival in patients with NPC, whereas T classification was not an independent prognostic factor. Among patients classified with N0-1 and N2-3, there were significant differences in the rates of distant metastasis between those with GTVp smaller and larger than 25 mL (p < .001 and p = .002, respectively).

CONCLUSIONS

GTVp is highly significant in evaluating local control, distant metastasis, and overall survival of patients with NPC treated with IMRT. Therefore, it is recommended that GTVp be included in the new TNM classification system.

Preclinical imaging of therapy response using metabolic and apoptosis molecular imaging

PURPOSE

Early after therapy, 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG) imaging is not always reliable due to the influx of inflammatory cells while apoptosis imaging offers a direct and early measurement of therapy effects. This study uses an improved apoptosis probe ((99m)Tc-hAnxA5) in combination with [(18)F]FDG imaging to evaluate therapy response.

PROCEDURES

Daudi tumor tissue was implanted in the spleen of SCID mice. Treatment was performed with adriamycin and cyclophosphamide. Sequential [(18)F]FDG-positron emission tomography (PET) was acquired over 6 days and (99m)Tc-hAnxA5-SPECT was performed before and 1 day after therapy.

RESULTS

On day 1, therapy induced apoptosis was visualized with (99m)Tc-hAnxA5 without a measurable change in [(18)F]FDG uptake. [(18)F]FDG uptake decreased significantly on day 3 and was even more pronounced on day 6.

CONCLUSION

In this preclinical model, (99m)Tc-hAnxA5 imaging was able to detect apoptosis before metabolic changes were measured. These results confirm the value of apoptosis imaging for therapy response and give more insight in [(18)F]FDG imaging and its parameters to evaluate response.

Prognostic significance of tumor volume in nasopharyngeal carcinoma

OBJECTIVE

To investigate the prognostic significance of primary and residual tumor volume in nasopharyngeal carcinoma.

METHODS

56 patients were included in the study. Diameters of tumors were measured from CT and MR film hardcopies. Diameter-based measurements were computed as an ellipsoid (V=4/3·π·d1·d2·d3) to calculate diameter-based volume. It was investigated whether primary tumor volume provided prognostic information about local regional recurrence free survival (LRRFS), disease free survival (DFS), distant metastasis free survival (DMFS) and overall survival (OS) by monovariant and multivariant analysis. Kaplan-Meier survival analysis method and log-rank test were used to estimate survival analysis (95% confidence interval). Cox regression test was used for two variant and multivariant survival analysis. Statistical Package for Social Sciences (SSSP) 10.0 for Windows programme was used for data analysis.

RESULTS

In the multivariate analysis, in the patients with tumor volume more than 60ml, local regional recurrence more frequently developed. The relationship between tumor volume and local regional recurrence was found significant (p=0.053). In the monovariate analysis, primary tumor volume was found to be a significant predictive value on DFS and DMFS. In the patients with tumor volume below 20ml, DFS was 60%, whereas in the patients with tumor volume above 60ml, DFS was 0% (p=0.007). The prevalence were 68% and 0% in the patients group that had tumor volume below 30ml and above 60ml respectively. DMSF ratios in the patients with primary tumor volume below 20ml and above 60ml were 86.67% and 33.3% respectively. The residual tumor volume (RTV) at first control after treatment was found to be a significant prognostic factor on LRRFS (p=0.03).

CONCLUSION

The foundation of new T staging systems that consists of PTV that was found as an independent prognostic factor alone in multivariate statistical analysis may precede better prediction of prognosis and more appropriate treatment of patients having different prognostic factors. RTV in the first control after treatment was a significant prognostic factor on LRRFS.

Significance of primary tumor volume and T-stage on prognosis in nasopharyngeal carcinoma treated with intensity-modulated radiation therapy

OBJECTIVE

The aim of this study was to evaluate the effect of the primary tumor volume on prognosis in nasopharyngeal carcinoma treated with intensity-modulated radiation therapy.

METHODS

Between August 2003 and April 2005, 112 patients with Stage I-IVB nasopharyngeal carcinoma treated by intensity-modulated radiation therapy were included. Measurement of the primary tumor volume was based on contrast-enhanced computed tomography scans before treatment. A receiver operating characteristics curve was used to determine the best cut-off point of the primary tumor volume.

RESULTS

The mean primary tumor volume for 112 patients with nasopharyngeal carcinoma was 33.9 ± 28.7 ml. Within the framework of UICC T-staging, all patients were divided into four groups according to the primary tumor volume. We call it the volume stage (V1 <15.65 ml, V2 = 15.65-24.25 ml, V3 = 24.25-50.55 ml and V4 >50.55 ml). The 5-year overall survival rates for V1, V2, V3 and V4 were 88.5, 83.3, 82.4 and 54.5% (P = 0.014), respectively. The cumulative survival curves for V1, V2 and V3 were very close, but clearly separated from V4. In addition, Cox proportional hazards regression model analysis showed that a primary tumor volume >50 ml was an independent risk factor for radiotherapy (risk ratio = 3.485, P = 0.025).

CONCLUSIONS

This study demonstrated that the primary tumor volume had significantly impacted on the prognosis of patients with nasopharyngeal carcinoma. We proposed that the primary tumor volume should be considered as an additional stage indicator in the new revision of the clinical stage of nasopharyngeal carcinoma.

Primary tumor volume is an independent predictor of outcome within pT4a-staged tongue carcinoma

Background

We evaluated the heterogeneity of primary tumor volume (PTV) within tumors of the same pT4a-staged tongue carcinoma and to elucidate the effects of PTV on treatment outcomes in patients with pT4a-staged tongue carcinoma.

Methods

Fifty-eight patients with newly diagnosed pT4a-staged tongue carcinoma who received surgery were enrolled onto this study. Magnetic resonance imaging–derived PTV was measured by the summation-of-area technique.

Results

The mean PTV was 24.55 ml, with a range of 5.32 to 119.64 ml. The receiver operating characteristic curve was applied, and the optimal cutoff volume was 23 ml. Large PTV was associated with a significantly poor disease-specific survival (P = 0.010) by the log rank test. The Cox regression model also revealed that large PTV (P = 0.026) and positive lymphatic node metastasis (P = 0.004) were statistically significant in the prognosis of T4a-staged tongue carcinoma.

Conclusions

A substantial variation of PTV was present within the same pT4a-staged tongue carcinoma, and PTV represented an important prognostic factor. In the light of these findings, we suggest that taking the PTV into account in pT4a-staged tongue carcinoma would better refine the newest revised T classification, and the treatment strategies may be different.

Induction chemotherapy with paclitaxel and cisplatin followed by radiotherapy for larynx organ preservation in advanced laryngeal and hypopharyngeal cancer offers moderate late toxicity outcome (DeLOS-I-trial)

A prospective multicenter phase-II trial (12 centers) was performed by the German larynx organ preservation group (DeLOS) to evaluate the effect of induction chemotherapy (ICHT) with paclitaxel/cisplatin (TP), followed by accelerated-hyperfractionated (concomitant boost) radiotherapy (RT) in responders. The trial was focused on larynx preservation, tumor control, survival, salvage surgery and late toxicity in patients with advanced larynx/hypopharynx carcinoma eligible for total laryngectomy (LE). Seventy-one patients (40 larynx, 87.5% St. III, IV; 31 hypopharynx, 93.4% St. III, IV) were enrolled into the study and treated with ICHT (200 mg/m(2) paclitaxel, 100 mg/m(2) cisplatin; day 1, 22) according to the DeLOS protocol. Patients with complete or partial tumor response proceeded to RT (69.9 Gy in 5.5 weeks). Non-responders received a LE followed by postoperative RT (56-70 Gy in 5.5-7 weeks). The response rate to ICHT for larynx cancer was 69.6% (7.1% complete, 62.5% partial response) and for hypopharyngeal cancer was 84.3% (6.9% complete, 77.4% partial response). Overall survival after 36 months was 60.3% (95% CI, 48.4-72.2%), after 42 months was 56.5% (95% CI, 44.2-68.8%). Laryngectomy-free survival was as follows: after 36 months, 43.0% (95% CI, 30.9-55.0%); after 42 months, 41.3% (95% CI, 29.3-53.3%). Both parameters did not show different outcomes after distinguishing larynx from hypopharynx. LE was indicated in 15 non-responders after ICHT. Five of the 15 non-responders refused the laryngectomy. Two of the five received RT instead and had no evidence of disease 42 months after RT. Late toxicity (dysphagia III, IV LENT SOMA score in laryngectomy-free survivors: after 6 months, 1.8%; 12 months, 11.4%; 18 months, 14.5%; 24 months, 8.1%; 36 months, 16%) and salvage surgery (4 pharyngocutaneous fistulas in 27 operations) were tolerable. In a large portion of patients eligible for LE, the larynx could be preserved with satisfying functional outcome. Good responders after ICHT had also a good general outcome with relatively rare severe late toxicities. Due to a slight increase of relevant late dysphagia, functional outcome regarding swallowing and tracheotomy free breathing should be more focused in future larynx organ preservation trials.

Primary tumor volume of nasopharyngeal carcinoma: significance for recurrence and survival

BACKGROUND

Primary tumor volume (PTV) is known to be a significant prognostic factor in malignant tumor. There have been several studies of nasopharyngeal carcinoma (NPC) relating tumor volume to treatment outcome. Our study was designed to evaluate the effect of PTV on treatment outcomes in NPC treated with radiotherapy (RT)/concurrent chemoradiotherapy (CCRT) or CCRT with adjuvant chemotherapy.

METHODS

We retrospectively reviewed 100 cases with newly diagnosed NPC who were treated with RT/CCRT or CCRT with adjuvant chemotherapy from 2002 to 2006. Magnetic resonance imaging-derived PTV was calculated using the summation-of-area technique. Kaplan-Meier plots and the log-rank test were used to estimate tumor recurrence (locoregional, distant, or both) and overall survival. Cox proportional hazards regression analysis was used to assess the prognostic impact of PTV.

RESULTS

The median PTV was 12.94 mL. PTV remained an independent prognostic factor for distant metastasis (hazard ratio [HR], 1.04; p=0.03), for any relapse (HR, 1.04; p=0.02), and for overall survival (HR, 1.09; p<0.001) in multivariate analysis. In the large tumor volume group (PTV>15 mL), patients' metastasis-free survival rates, with and without adjuvant chemotherapy, were 100% and 68.3%, respectively (p=0.002). Their 3-year recurrence-free survival rates, with and without adjuvant chemotherapy, were 94.1% and 69.6%, respectively (p=0.006). In the small tumor volume group (PTV <or= 15 mL), this phenomenon was not observed.

CONCLUSION

PTV had a close relationship with survival rates and recurrence rates in patients with NPC. The large tumor volume group (PTV>15 mL) was associated with more recurrence and poor survival rate, and it was suggested that these high-risk patients should benefit from CCRT followed by adjuvant chemotherapy.

Prognostic impact of primary tumor volume in patients with nasopharyngeal carcinoma treated by definitive radiation therapy

OBJECTIVES/HYPOTHESIS

Tumor burden has been confirmed as one of the important indicators in disease control after treatment for various types of malignancies. This report aims to document the value of the primary tumor volume of nasopharyngeal carcinoma [gross tumor volume of the primary site (GTV-P)] in predicting the treatment outcome after high-dose definitive radiation therapy.

STUDY DESIGN

A total of 154 patients with nasopharyngeal carcinoma were prospectively treated with accelerated hyperfractionated radiotherapy alone to a total dose of 78 Gy/60 fractions/6 weeks (biological effective dose = 88.2 Gy).

METHODS

Patients were assessed for local control, disease-free survival and distant failure free survival. The GTV-P was calculated by summation of area technique after delineation of the primary tumor contours on computed tomography images.

RESULTS

The median GTV-P was 14.5 mL for T1, 23.3 mL for T2, 35.8 mL for T3, and 50.9 mL for T4 diseases (P < .05). With a median follow-up of 61 months, the 5-year local failure-free rate, disease-free survival and distant failure-free survival rates were 89.4% versus 48.9% (P = .002), 56.6% versus 0% (P = .001), and 66.9% versus 16.5% (P = .0001), respectively, for patients whose GTV-P were < or =60 mL and >60 mL. Multivariate analysis revealed that GTV-P is an independent prognostic factorfor local control (hazard ratio = 3.568, P = .035). There fore, the GTV-P was significantly associated with the treatment outcome after high-dose radiation delivered in accelerated hyperfractionated schedule for nasopharyngeal cancer patients.

CONCLUSIONS

Tumor volume is a reliable indicator for supplementing the T classification of the Tumor, Node, Metastasis staging system for predicting local control after definite radiation therapy.

Nasopharyngeal carcinoma

Imaging plays an important role in the staging of nasopharyngeal carcinoma. Accurate staging is necessary, as the treatment is directly dependent on stage. Clinical examination provides information on mucosal involvement but is unable to determine the deep extension or the presence of skull base invasion or intracranial spread. The intent of this manuscript is to provide information of the specific imaging findings that will directly affect the stage and treatment of nasopharyngeal carcinoma as well as post-treatment complications.

Primary tumor volume of nasopharyngeal carcinoma: significance for survival

OBJECTIVES

To elucidate the effect of primary tumor volume (PTV) on treatment outcomes in patients with nasopharyngeal carcinoma (NPC) who were treated with radiotherapy or concurrent chemoradiotherapy. The TNM staging system developed by American Joint Committee of Cancer (AJCC) is universally used and accepted but its prediction of prognosis in NPC receives a lot of challenge. Primary tumor volume had been reported to have close relationship with prognosis of head and neck cancer. We may predict prognosis of NPC with PTV.

METHODS

From 1999 to 2006, 91 patients with newly diagnosed NPC who were treated with radiotherapy or CCRT were enrolled in the study. Computed tomography-derived or magnetic resonance-derived primary tumor volume was calculated. The correlation between AJCC disease stage, primary tumor volume and disease-specific survival were analyzed. Multivariate analyses using the Cox proportional hazard model was performed.

RESULTS

The median primary tumor volume for the whole series was 11.39 ml (range 1.25-166.58 ml). The median primary tumor volume was 2.69 ml in T1 disease, 10.14 ml in T2 disease, 15.41 ml in T3 disease, and 26.69 ml in T4 disease. Hazard ratio increased with tumor volume, ranging from 5.91 (95% confidence interval (95% CI) 1.13-26.43) for tumor volumes between 20 ml and 40 ml, and 15.72 (95% CI, 3.82-61.05) for tumor volumes >40 ml. With both tumor volume and T classification in the same Cox regression model, only tumor volume remained statistically significant in the prognosis of NPC.

CONCLUSION

Primary tumor volume has closer relationship with survival rates of patients with NPC. Calculation of primary tumor volume may be further considered to improve the current staging system.

Primary tumor volume calculation as a predictive factor of prognosis in nasopharyngeal carcinoma

CONCLUSIONS

Primary tumor volume (PTV) has a close relationship with survival rates of patients with nasopharyngeal carcinoma (NPC) who were treated with concurrent chemoradiotherapy (CCRT) or radiotherapy. Besides the current AJCC staging system, measurement of PTV may be needed to predict prognosis of NPC and adjust treatment strategy.

OBJECTIVES

We conducted a retrospective study to elucidate the effect of PTV on treatment outcomes in patients with NPC who were treated with CCRT or radiotherapy.

PATIENTS AND METHODS

A total of 66 patients with newly diagnosed NPC were enrolled in this study. Computed tomography (CT)-derived or magnetic resonance imaging (MRI)-derived PTV was calculated. The correlation between AJCC disease stage, PTV, and disease-specific survival was analyzed. Correlations between different prognostic factors were assessed using a Cox regression model.

RESULTS

The median PTV for the whole series was 12.01 ml (range 1.25-166.58 ml). The median PTV was 3.45 ml in T1 disease, 7.96 ml in T2 disease, 17.95 ml in T3 disease, and 64.73 ml in T4 disease. Disease stage and T stage carried no prognostic significance (p=0.25 and p =0.30, respectively). Four categories of PTV (<12.5 ml, 12.5-25 ml, 25-50 ml and >50 ml) had prognostic significance (p=0.02). Survival analysis demonstrated a significant difference in overall survival with larger tumor volume (risk ratio 5.447; p=0.044).

Tumour volume measurement in head and neck cancer

Tumour volume is a significant prognostic factor in the treatment of malignant head and neck tumours. Studies of laryngeal and pharyngeal tumours have shown tumour volume to be an important predictor for tumour recurrence. Some studies (for instance nasopharyngeal carcinoma) have shown through multivariate modelling that tumour volume is a dominant covariate that overwhelms T stage, N stage and stage group. The results of these studies have prompted several investigators to suggest the inclusion of tumour volume as an additional prognostic factor in future revisions of the TNM staging system. This paper briefly reviews the TNM system as a staging tool, the measurement of tumour volume and how tumour volume could possibly be incorporated in the system or used as an additional prognostic factor.

[Accelerated hyperfractionated radiotherapy with concurrent chemotherapy in locally advanced nasopharyngeal carcinomas]

BACKGROUND

The excellent results yielded by hyperfractionated and accelerated radiotherapy associated with concurrent chemotherapy in locally advanced oropharyngeal and hypopharyngeal carcinomas led to investigation of this therapeutic regimen in nasopharyngeal carcinomas also.

METHODS

Thirty-five patients with stage III and IV nasopharyngeal carcinomas received accelerated hyperfractionated radiotherapy with concurrent chemotherapy (5-FU, mitomycin C + leucovorin). In the first 3 weeks of treatment five 2-Gy doses per week were delivered to the primary tumour and regional lymph nodes. The fractionation was then accelerated, with 1.4 Gy given twice daily until a total dose of 72 Gy had been administered.

RESULTS

The overall objective response rate was 100%. The median follow-up period was 71 months. Salvage surgery of the lymph nodes was performed in 10 patients, revealing vital tumour tissue in 6 of these. The actuarial 5-year local control rate was 64% (95%CI: 47-81%), while overall actuarial survival at 5 years was 70% (95%CI: 53-86%).

CONCLUSION

Hyperfractionated accelerated radiotherapy with concurrent chemotherapy is effective and feasible in locally advanced nasopharyngeal carcinoma.

The relationship between nasopharyngeal carcinoma tumor volume and TNM T-classification: a quantitative analysis

Recent findings show that tumor volume is a significant prognostic factor for the treatment of nasopharyngeal carcinoma (NPC). The inclusion of tumor volume as an additional prognostic factor in the UICC TNM classification system was suggested; however, how tumor volume could possibly be incorporated is still unexplored. In this paper, we report a quantitative analysis on the relationship between NPC tumor volume and T-classification, using the data from 206 NPC patients. By T-classification and semi-automatic tumor volume measurement, the difference in tumor volumes among the various TNM T-classification groups was examined. In addition, a statistics-based analysis scheme, which used the T-classification as the "gold standard", was proposed to classify NPC tumors into volume-based groups to explore the possible links. The results show that NPC tumor volume has positive correlation with advancing T-classification groups and significant difference existed in the distribution of T-classification among various volume-based groups (P < 0.001). By the proposed statistical scheme, tumor volume could be included as an additional prognostic factor in the TNM framework, following validation studies.

Dose–response relationship of nasopharyngeal carcinoma above conventional tumoricidal level: A study by the Hong Kong nasopharyngeal carcinoma study group (HKNPCSG)

BACKGROUND AND PURPOSE

To define the dose-response relationship of nasopharyngeal carcinoma (NPC) above the conventional tumoricidal dose level of 66 Gy when the basic radiotherapy (RT) course was given by the 2D Ho's technique.

PATIENTS AND METHODS

Data from all five regional cancer centers in Hong Kong were pooled for this retrospective study. All patients (n = 2426) were treated with curative-intent RT with or without chemotherapy between 1996 and 2000 with the basic RT course using the Ho's technique. The primary endpoint was local control. The prognostic significance of dose-escalation ('boost') after 66 Gy, T-stage, N-stage, use of chemotherapy, sex and age (< or =40 years vs >40 years) was studied. Both univariate and multivariate analyses were performed.

RESULTS

On multivariate analysis, T-stage (P < 0.01; hazard ratio [HR], 1.58) and optimal boost (P = 0.01; HR, 0.34) were the only significant factors affecting local failure for the whole study population, and for the population of patients treated by radiotherapy alone, but not for patients who also received chemotherapy. The following were independent determinants of local failure for patient groups with different T-stages treated by radiotherapy alone: use of a boost in T1/T2a disease (P = 0.01; HR, 0.33); use of a boost (P < 0.01; HR, 0.60) and age (P = 0.01; HR, 1.02) in T3/T4 tumors. Among patients with T2b tumors treated by radiotherapy alone and given a boost, the use of a 20 Gy-boost gave a lower local failure rate than a 10 Gy-boost. There was no apparent excess mortality attributed to RT complications.

CONCLUSIONS

Within the context of a multi-center retrospective study, dose-escalation above 66 Gy significantly improved local control for T1/T2a and T3/4 tumors when the primary RT course was based on the 2D Ho's technique without additional chemotherapy. 'Boosting' in NPC warrants further investigation. Caution should be taken when boosting is considered because of possible increase in radiation toxicity.

Correlation between MR imaging–derived nasopharyngeal carcinoma tumor volume and TNM system

PURPOSE

To measure nasopharyngeal carcinoma tumor volume based on magnetic resonance images using a validated semiautomated measurement methodology and correlate tumor volume with TNM T classification.

METHODS AND MATERIALS

The study population consisted of 206 consecutive nasopharyngeal carcinoma patients who had magnetic resonance imaging staging scans. Tumor volume was measured using a semisupervised knowledge-based fuzzy clustering algorithm. Patients were divided into 4 groups according to TNM T classification. The difference in tumor volumes among the various TNM T-classification groups was examined.

RESULTS

The mean tumor volume in each T-classification group is as follows: T1, 8.6 mL +/- 5.0 (standard deviation [SD]); T2, 18.1 mL +/- 8.1 (SD); T3, 25.8 mL +/- 14.1 (SD); and T4, 36.2 mL +/- 18.9 (SD). The mean tumor volume increased significantly with advancing T classification (p < 0.0001). Tumor volume in a more advanced T group was significantly larger than that in an adjacent early T group (p < 0.01).

CONCLUSION

Validated magnetic resonance imaging-based tumor volume shows positive correlation between tumor volume and advancing T-classification groups. It may be possible to incorporate tumor volume as an additional prognostic factor into the existing TNM system.

Semi-automated brain tumor and edema segmentation using MRI

PURPOSE

Manual segmentation of brain tumors from magnetic resonance images is a challenging and time-consuming task. A semi-automated method has been developed for brain tumor and edema segmentation that will provide objective, reproducible segmentations that are close to the manual results. Additionally, the method segments non-enhancing brain tumor and edema from healthy tissues in magnetic resonance images.

METHODS AND MATERIALS

In this study, a semi-automated method was developed for brain tumor and edema segmentation and volume measurement using magnetic resonance imaging (MRI). Some novel algorithms for tumor segmentation from MRI were integrated in this medical diagnosis system. We exploit a hybrid level set (HLS) segmentation method driven by region and boundary information simultaneously, region information serves as a propagation force which is robust and boundary information serves as a stopping functional which is accurate. Ten different patients with brain tumors of different size, shape and location were selected, a total of 246 axial tumor-containing slices obtained from 10 patients were used to evaluate the effectiveness of segmentation methods.

RESULTS

This method was applied to 10 non-enhancing brain tumors and satisfactory results were achieved. Two quantitative measures for tumor segmentation quality estimation, namely, correspondence ratio (CR) and percent matching (PM), were performed. For the segmentation of brain tumor, the volume total PM varies from 79.12 to 93.25% with the mean of 85.67+/-4.38% while the volume total CR varies from 0.74 to 0.91 with the mean of 0.84+/-0.07. For the segmentation of edema, the volume total PM varies from 72.86 to 87.29% with the mean of 79.54+/-4.18% while the volume total CR varies from 0.69 to 0.85 with the mean of 0.79+/-0.08. The HLS segmentation method perform better than the classical level sets (LS) segmentation method in PM and CR.

CONCLUSIONS

The results of this research may have potential applications, both as a staging procedure and a method of evaluating tumor response during treatment, this method can be used as a clinical image analysis tool for doctors or radiologists.

Prognostic value of tumor volume in nasopharyngeal carcinoma

Tumor bulk has been recognized as an important prognostic factor in the treatment of malignancy. The purpose of the present study is to investigate the prognostic value of tumor volume in nasopharyngeal carcinoma. Sixty patients with nasopharyngeal carcinoma were included in this study. Tumor contour was outlined on each of the computed tomography (CT) images using an image analyzer. The primary tumor volume (PTV) and nodal tumor volume (NTV) were calculated by a summation-of-areas technique, and the maximal perimeter of primary tumor (MPP) was measured. The loco-regional control rates and disease-specific survival rates were analyzed according to several variables. The patients had a 5-year local control rate of 75.5%, 5-year nodal control rate of 74.6%, and 5-year disease-specific survival rate of 60.2%. Large PTV ( > 30 cm3) was associated with a significantly lower local control (p=0.005). Large NTV ( > 5 cm3) was associated with a significantly lower nodal control (p=0.019) and lower disease-specific survival (p=0.046). Large MPP ( > 18 cm) was associated with a significantly lower local control (p=0.017). In multivariate analysis, the PTV and NTV were found to be independent factors in predicting the local (p=0.015) and nodal (p=0.039) control, respectively. The NTV (p=0.012) and cranial nerve involvement (p=0.009) were factors that predicted disease-specific survival. Our results suggest that the estimation of tumor volume may identify a subgroup of patients with a greater risk of loco-regional failure and can be used to refine the current staging system.

Nasopharyngeal Carcinoma Tumor Volume Measurement1

Tumor volume was measured in 69 patients with nasopharyngeal carcinoma. On transverse nonenhanced T1-weighted and gadolinium-enhanced T1-weighted magnetic resonance (MR) images, segmentation was performed by means of seed growing and knowledge-based fuzzy clustering methods. Data were compared with those collected with the manual tracing method and analyzed for interoperator variance and interobserver reliability. There was no significant difference between the volumes determined with manual tracing or semiautomated segmentation (P >.05). On the volume level, Pearson correction coefficients were close for both the manual tracing and semiautomated methods. Significant differences in interoperator variance existed between the two methods on the pixel level (P <.05). Compared with manual tracing, the semiautomated method helped reduce interoperator variance and obtain higher interobserver reliability. Findings in the current study validate the use of semiautomated volume measurement methods for nasopharyngeal carcinoma.

Tongue carcinoma: tumor volume measurement

PURPOSE

To validate the semiautomated methods of tongue carcinoma tumor volume measurement by comparing the conventional manual trace method with 2 semiautomated computer methods: seed growing and region deformation.

MATERIALS AND METHODS

The study population consisted of 16 patients with histology-proven tongue carcinoma. Two head-and-neck radiologists independently measured the tumor volume demonstrated on pretreatment T2-weighted magnetic resonance data sets. The tumor volumes were measured using manual tracing and semiautomated seed growing and region deformation algorithm. Data were recorded for analysis of interoperator variance and interobserver reliability at volume and pixel levels.

RESULTS

There was no significant difference between the manually traced volume and semiautomated segmentation volumes for both operators. No significant difference was found in interobserver variance among the 3 methods at volume level. However, there was significant difference between manual tracing and semiautomated segmentation methods in interobserver reliability at pixel level.

CONCLUSION

The semiautomated methods could achieve satisfactory segmentation results. They could also reduce interoperator variance and obtain a higher interobserver reliability. This study validates the use of semiautomated volume measurement methods for tongue carcinoma.

Primary tumor volume of nasopharyngeal carcinoma: prognostic significance for local control

PURPOSE

To study the prognostic significance of primary tumor volume on local control of nasopharyngeal carcinoma.

METHODS AND MATERIALS

Between 1998 and 2001, 308 consecutive patients with nasopharyngeal carcinoma treated with radical intent were staged with MRI. On the basis of the extent of tumor infiltration outlined by a diagnostic radiologist, the gross tumor volume of the primary and involved retropharyngeal nodes (GTV-P) was delineated by a radiation oncologist for three-dimensional conformal radiotherapy to the nasopharyngeal region using the Helax-TMS Planning System. All patients were treated with 2 Gy daily to a total dose of 70 Gy in 6-7 weeks. Additionally, chemotherapy was given to 128 patients (42%).

RESULTS

The median GTV-P for the whole series was 22 cm(3) (range, 1.4-218 cm(3)). Although the GTV-P varied substantially within each T stage, the overall correlation between these two parameters was strongly significant (p <0.01), with the median GTV-P 2.7 cm(3) for T1, 13.2 cm(3) for T2, 28.1 cm(3) for T3, and 65.5 cm(3) for T4. With a median follow-up of 1.9 years (range, 0.1-3.9 years), the 3-year local failure-free rate was 87%. The 3-year local failure-free rate was 97% for patients with a GTV-P <15 cm(3) compared with 82% for those with a GTV-P > or =15 cm(3) (p <0.01). On multivariate analysis (with T stage as a covariate), GTV-P remained an independent prognostic factor for the local failure-free rate (hazard ratio, 1.01; 95% confidence interval, 1.00-1.02; p <0.01).

CONCLUSION

Our data suggested that GTV-P is a strongly significant factor for predicting local control of nasopharyngeal carcinoma. The risk of local failure was estimated to increase by 1% for every 1 cm(3) increase in primary tumor volume.

Tumor volume is not an independent prognostic factor in early-stage nasopharyngeal carcinoma treated by radiotherapy alone

PURPOSE

To determine whether the tumor volume can predict the treatment outcome in early-stage nasopharyngeal carcinoma (NPC) treated by radiotherapy alone.

METHODS AND MATERIALS

The pretreatment CT scans of 116 patients with American Joint Committee on Cancer Stage I-II NPC treated by radiotherapy alone were retrospectively reviewed. The clinician outlined the tumor extent. The primary tumor volume (PTV) and nodal volume (NV) were then calculated by a summation-of-areas technique. The PTV and NV were correlated with locoregional control, distant failure, and survival. The median follow-up time was 105 months.

RESULTS

Patients with Stage I disease had a 5-year locoregional control rate of 95% and a disease-specific survival (DSS) rate of 97%; for Stage II disease, the corresponding rates were 81% and 79%. The PTV ranged from 1.3 to 75.5 cm3 (median, 12.6 cm3), with substantial overlap between T1 and T2 disease. The NV ranged from 0 to 35.4 cm(3). Patients with a PTV >15 cm3 had significantly worse local control (5-year control rate, 82% vs. 93%; p = 0.033), but no statistically significant difference was noted in survival (5-year DSS rate, 83% vs. 89%; p = 0.30). The difference in local control was mainly seen in those with T2 disease. Patients with NV >4 cm3 had a greater distant failure rate (5-year distant metastasis-free rate, 72% vs. 90%; p = 0.011) and worse survival (5-year DSS rate, 76% vs. 94%; p = 0.0038). Nodal control was excellent with no difference between a NV of < or =4 cm3 and a NV of >4 cm3 (5-year control rate, 97% vs. 100%). The survival rate was worst in patients with a PTV >15 cm3 and a NV >4 cm3 (5-year DSS rate, 68%) and best in those with a PTV of < or =15 cm3 and a NV of < or =4 cm3 (5-year DSS rate, 92%). Multivariate analysis, however, showed that only parapharyngeal extension (T2b) and N1 stage were independent factors that predicted locoregional control and survival, and N1 stage was the only factor that predicted distant failure.

CONCLUSION

The pretreatment tumor volume has a limited prognostic value in early-stage NPC compared with the usual T and N classification, with Stage T2b and N1 as independent factors that predicted treatment outcome. Within T2 disease, the estimation of tumor volume may identify a subgroup of patients with a greater risk of local failure that warrants more aggressive treatment.

Better prediction of prognosis for patients with nasopharyngeal carcinoma using primary tumor volume

BACKGROUND

Heterogeneity of primary tumor volume within tumors of the same classification indicates a need to elucidate the effects of primary tumor volume on treatment outcomes in patients with nasopharyngeal carcinoma (NPC).

METHODS

From 1994 through 1996, 129 patients with newly diagnosed NPC who were treated with high-dose radiotherapy were enrolled in the study. Computed tomography-derived primary tumor volume was measured using the summation-of-area technique. Correlations between American Joint Committee on Cancer (AJCC) disease stage, primary tumor volume, and disease-specific survival were assessed using a Cox regression model. Cross-validation based on receiver operating characteristic (ROC) curve also was examined.

RESULTS

Compared with the AJCC staging system and the TNM classification system, primary tumor volume was better at determining cumulative survival for patients with NPC. Hazard ratios increased with tumor volume, ranging from 6.68 (95% confidence interval [95% CI], 1.89-23.67) for tumor volumes between 20-40 mL, 18.03 (95% CI, 4.80-67.75) for tumor volumes between 40-60 mL, and 26.06 (95% CI, 7.70-88.20) for tumor volumes > 60 mL. With both tumor volume and T classification in the same Cox regression model, only tumor volume remained statistically significant in the prognosis of NPC. The validation results with ROC curves also revealed that, in predicting patient outcome, primary tumor volume (area under the ROC = 83.33%) was superior to disease stage (area under the ROC = 66.53%) and TNM classification (area under the ROC = 58.61%).

CONCLUSIONS

The incorporation of primary tumor volume may lead to a further refinement of the current AJCC staging system, particularly for patients with large primary tumor volumes (> 60 mL), who require more aggressive treatment. Cancer 2004.

Segmentation and visualization of nasopharyngeal carcinoma using MRI

In this study, a semi-automatic system was developed for nasopharyngeal carcinoma (NPC) tumor segmentation, volume measurement and visualization using magnetic resonance imaging (MRI). Some novel algorithms for tumor segmentation from MRI and inter-slice interpolation were integrated in this medical diagnosis system. This system was applied to 10 MR image data sets of NPC patients and satisfactory results were achieved. This system can be used as a clinical image analysis tool for doctors or radiologists to obtain tumor location from MRI, tumor volume estimation, and 3D information.

Induction chemotherapy with paclitaxel and cisplatin and CT-based 3D radiotherapy in patients with advanced laryngeal and hypopharyngeal carcinomas--a possibility for organ preservation

BACKGROUND

To evaluate the effect of paclitaxel/cisplatin induction chemotherapy (ICHT) and CT-based radiotherapy (RT) on larynx preservation, tumor control, and survival in patients with larynx/hypopharynx carcinoma eligible for total laryngectomy (TL) or TL plus partial pharyngectomy (TLPP).

PATIENTS AND METHODS

Fifty patients eligible for TL or TLPP were enrolled onto a prospective study and treated with ICHT (200 mg/m(2) paclitaxel, 100 mg/m(2) cisplatin; day 1, 22). In patients with complete or partial tumor response RT (69.9 Gy in 5.5 weeks at the gross tumor, 50.4 Gy in the lymphatic drainage; single dose: 1.8 Gy, concomitant boost: 1.5 Gy) was applied. Non-responders had TL/TLPP and RT with total doses adapted to the radicality of tumor resection (56-70 Gy).

RESULTS

The response rate to ICHT was 88% (10% complete, 78% partial response). At a median follow-up period of 25 months the larynx preservation rate was 84%. The 2-year local-regional control rate was 91% and the 2-year overall survival rate was 72.3%. The 3-year estimate to survive with functional larynx is 60%.

CONCLUSION

In a large portion of patients eligible for TL or TLPP the larynx was preserved by paclitaxel/cisplatin ICHT and 3D RT.

[Volume-effect in radiation therapy part one: volume-effect and tumour]

Volume is an important parameter of radiation therapy. Local control is inversely related to tumor size and the complication rate increases with the importance of the irradiated volume. Although the effect of irradiated volume has been widely reported since the beginning of radiotherapy, it has been less studied than other radiation parameters such as dose, fractionation, or treatment duration. One of the first organ system in which the adverse effect of increased volume was well defined is the skin. Over the last twenty years, numerous mathematical models have been developed for different organs. In this report we will discuss the relation between irradiated volume and tumor control. In a second article we will study the impact of irradiated volume on radiation adverse effects.

Does delay in starting treatment affect the outcomes of radiotherapy? A systematic review

PURPOSE

The objective of this study was to synthesize what is known about the relationship between delay in radiotherapy (RT) and the outcomes of RT.

METHODS

A systematic review of the world literature was conducted to identify studies that described the association between delay in RT and the probability of local control, metastasis, and/or survival. Studies were classified by clinical and methodologic criteria and their results were combined using a random-effects model.

RESULTS

A total of 46 relevant studies involving 15,782 patients met our minimum methodologic criteria of validity; most (42) were retrospective observational studies. Thirty-nine studies described rates of local recurrence, 21 studies described rates of distant metastasis, and 19 studies described survival. The relationship between delay and the outcomes of RT had been studied in diverse situations, but most frequently in breast cancer (21 studies) and head and neck cancer (12 studies). Combined analysis showed that the 5-year local recurrence rate (LRR) was significantly higher in patients treated with adjuvant RT for breast cancer more than 8 weeks after surgery than in those treated within 8 weeks of surgery (odds ratio [OR] = 1.62, 95% confidence interval [CI], 1.21 to 2.16). Combined analysis also showed that the LRR was significantly higher among patients who received postoperative RT for head and neck cancer more than 6 weeks after surgery than among those treated within 6 weeks of surgery (OR = 2.89; 95% CI, 1.60 to 5.21). There was little evidence about the impact of delay in RT on the risk of metastases or the probability of long-term survival in any situation.

CONCLUSION

Delay in the initiation of RT is associated with an increase [corrected] in LRR in breast cancer and head and neck cancer. Delays in starting RT should be as short as reasonably achievable.