The impact of primary tumor volume on local control for oropharyngeal squamous cell carcinoma treated with radiotherapy

Importance of tumor volume, overall treatment time and fractionation sensitivity for p16-positive and p16-negative oropharyngeal tumors

BACKGROUND

Analyses of clinical outcomes following radiotherapy (RT) have advanced our understanding of fundamental radiobiological characteristics in head and neck squamous cell carcinoma (HNSCC). Low fractionation sensitivity appears to be a common feature, as well as susceptibility to changes in overall treatment time (OTT). Large tumors should be harder to cure if a successful RT requires the sterilization of all clonogenic cells. Congruently, primary tumor volume has proven to be an important parameter. However, most findings come from an era when p16-negative HNSCC was the dominant tumor type. HPV-associated, p16-positive, oropharyngeal tumors (OPSCC) are more radiosensitive and have better outcome. The current study aims to investigate the role of primary tumor volume, OTT and estimate α/ β -ratio for p16-positive OPSCC, and to quantify the differences in radiosensitivity depending on p16-status.

METHODS

A cohort of 523 patients treated with RT was studied using a tumor control probability (TCP)-model that incorporates primary tumor volume (V) raised to an exponent c, OTT and α/ β -estimation. The significance of V was also investigated in Cox-regression models.

RESULTS

In the p16-positive cohort (n = 433), the volume exponent c was 1.44 (95%CI 1.06-1.91), compared to 0.90 (0.54-1.32) for p16-negative tumors (n = 90). Hazard ratios per tumor volume doubling were 2.37 (1.72-3.28) and 1.83 (1.28-2.62) for p16-positive and p16-negative, respectively. The estimated α/ β -ratio was 9.7 Gy (-2.3-21.6), and a non-significant daily loss of 0.30 Gy (-0.17-0.92) was found. An additional dose of 6.8 Gy (interquartile range 4.8-9.1) may theoretically counteract the more radioresistant behavior of p16-negative tumors.

CONCLUSION

Primary tumor volume plays a crucial role in predicting local tumor response, particularly in p16-positive OPSCC. The estimated α/β-ratio for p16-positive oropharyngeal tumors aligns with previous HNSCC studies, whereas the impact of prolonged OTT was slightly less than previously reported. The differences in radiosensitivity depending on p16-status were quantified. The findings should be validated in independent cohorts.

Primary tumor volume and prognosis for patients with p16-positive and p16-negative oropharyngeal squamous cell carcinoma treated with radiation therapy

BACKGROUND

The prescribed radiation dose to patients with oropharyngeal squamous cell carcinoma (OPSCC) is standardized, even if the prognosis for individual patients may differ. Easy-at-hand pre-treatment risk stratification methods are valuable to individualize therapy. In the current study we assessed the prognostic impact of primary tumor volume for p16-positive and p16-negative tumors and in relationship to other prognostic factors for outcome in patients with OPSCC treated with primary radiation therapy (RT).

METHODS

Five hundred twenty-three OPSCC patients with p16-status treated with primary RT (68.0 Gy to 73.1 Gy in 7 weeks, or 68.0 Gy in 4.5 weeks), with or without concurrent chemotherapy, within three prospective trials were included in the study. Local failure (LF), progression free survival (PFS) and overall survival (OS) in relationship to the size of the primary gross tumor volume (GTV-T) and other prognostic factors were investigated. Efficiency of intensified RT (RT with total dose 73.1 Gy or given within 4.5 weeks) was analyzed in relationship to tumor volume.

RESULTS

The volume of GTV-T and p16-status were found to be the strongest prognostic markers for LF, PFS and OS. For p16-positive tumors, an increase in tumor volume had a significantly higher negative prognostic impact compared with p16-negative tumors. Within a T-classification, patients with a smaller tumor, compared with a larger tumor, had a better prognosis. The importance of tumor volume remained after adjusting for nodal status, age, performance status, smoking status, sex, and hemoglobin-level. The adjusted hazard ratio for OS per cm³ increase in tumor volume was 2.3% (95% CI 0-4.9) for p16-positive and 1.3% (95% 0.3-2.2) for p16-negative. Exploratory analyses suggested that intensified RT could mitigate the negative impact of a large tumor volume.

CONCLUSIONS

Outcome for patients with OPSCC treated with RT is largely determined by tumor volume, even when adjusting for other established prognostic factors. Tumor volume is significantly more influential for patients with p16-positive tumors. Patients with large tumor volumes might benefit by intensified RT to improve survival.

Does Tumor Volume Have a Prognostic Role in Oropharyngeal Squamous Cell Carcinoma? A Systematic Review and Meta-Analysis

The aim of this study was to assess the prognostic value of tumor volume in oropharyngeal squamous cell carcinoma (OPSCC). The study was performed according to the PRISMA guidelines. A total of 1417 patients with a median age of 59.3 years (IQR 57.5−60) were included. The combined Hazard Ratios (HRs) for overall survival (OS) were 1.02 (95% CI, 0.99−1.05; p = 0.21) for primary tumor volume (pTV) and 1.01 (95% CI, 1.00−1.02; p = 0.15) for nodal tumor volume (nTV). Regarding locoregional control (LRC), the pooled HRs were 1.07 (95% CI, 0.99−1.17; p = 0.10) for pTV and 1.02 (95% CI, 1.01−1.03; p < 0.05) for nTV. Finally, the pooled HRs for disease-free survival (DFS) were 1.01 (95% CI, 1.00−1.03; p < 0.05) for pTV and 1.02 (95% CI, 1.01−1.03; p < 0.05) for nTV. In conclusion, pTV and nTV seem not to behave as reliable prognostic factors in OPSCC.

Altered fractionation diminishes importance of tumor volume in oropharyngeal cancer: Subgroup analysis of ARTSCAN-trial

BACKGROUND

A large tumor volume negatively impacts the outcome of radiation therapy (RT). Altered fractionation (AF) can improve local control (LC) compared with conventional fractionation (CF). The aim of the present study was to investigate if response to AF differs with tumor volume in oropharyngeal cancer.

METHODS

Three hundred and twenty four patients with oropharyngeal cancer treated in a randomized, phase III trial comparing CF (2 Gy/d, 5 d/wk, 7 weeks, total dose 68 Gy) to AF (1.1 Gy + 2 Gy/d, 5 d/wk, 4.5 weeks, total dose 68 Gy) were analyzed.

RESULTS

Tumor volume had less impact on LC for patients treated with AF. There was an interaction between tumor volume and fractionation schedule (P = .039). This differential response was in favor of CF for small tumors and of AF for large tumors.

CONCLUSION

AF diminishes the importance of tumor volume for local tumor control in oropharyngeal cancer.

CT-based volumetric tumor growth velocity: A novel imaging prognostic indicator in oropharyngeal cancer patients receiving radiotherapy

OBJECTIVES

Volumetric tumor growth velocity (TGV) reflects in vitro tumor aggressiveness, but its prognostic value has not been investigated in vivo. We examined the prognostic impact of TGV on oncologic outcomes in patients with oropharyngeal squamous cell cancer (OSCC).

MATERIALS AND METHODS

101 OSCC patients with two pretreatment CTs with time gap of 2 or more weeks treated at a single institution between 2004 and 2008 were identified. Primary tumor and nodal targets were segmented in scans. Linear growth rates were calculated. Recursive partitioning analysis (RPA) identified cut point associated with outcomes.

RESULTS

Median follow-up was 59months (range 7-118). Median primary TGV was 0.65% increase per day (range 0-9.37%). RPA identified TGV cut point associated with local control (LC) of 1% per day. Patients with higher TGV had decreased 5-year LC (73% vs. 98%, p=0.0004), distant control (DC, 62% vs. 91%, p=0.0007), and overall survival (OS, 38% versus 93%, p<0.0001). In multivariate analysis including demographics, tumor stage, subsite, and treatment factors, TGV⩾1% per day independently predicted worsened LC (p = 0.02), DC (p = 0.003), and OS (p < 0.0001). However, this TGV cutoff was not significantly predictive of LC, DC, or OS for a subset of presumed HPV-positive patients.

CONCLUSION

OSCC TGV⩾1% per day is a substantive negative prognostic indicator for disease control and overall survival, particularly in HPV non-associated tumors. This novel CT-based volumetric assessment of TGV suggests a simple methodology for risk stratification of patients.

Spatially Fractionated GRID Radiation Treatment of Advanced Neck Disease Associated with Head and Neck Cancer

Advanced nodal disease associated with head and neck cancer warrants aggressive, often multi-modality therapy to maximize local-regional control. The expansion of a novel treatment paradigm developed by our institution includes the addition of a single-fraction of high dose spatially-fractionated radiation (GRID) to a conventional course of treatment.

Between 1995 and 2002 a series of 27 patients (median age 65) with bulky N2-3 disease were treated. Median nodal tumor size was 7 cm. Two groups of patients were evaluated. Group 1 (N=14) patients received a median neck dose 69 Gy (range 54–79 Gy) plus GRID treatment. Group 2 (N=13) patients received a median neck dose of 59 Gy (range 54–72 Gy) plus GRID treatment followed by planned neck dissection. Patients were evaluated for local-regional control, pathological response, survival, and morbidity.

Median time to follow-up for Group 1 was 10 months (range 3–44 months). Neck control was 93%. Disease specific survival was 50%. Morbidity was limited to soft-tissue related damage and was mild. Median time to follow-up for Group 2 was 38 months (range 5–116 months). Pathologic complete response rate was 85%. Overall neck control rate was 92%. Disease specific survival was 85%. Surgical morbidity was limited to three wound healing complications.

GRID treatment may be safely added to conventional treatment management of locally advanced neck disease related to cancer with acceptable morbidity. It may improve pathologic complete response rates in those patients who undergo planned neck dissection, possibly leading to improved survival. In patients with inoperable bulky disease, addition of GRID enhances local-regional control.

External validation of sTWEAK as a prognostic noninvasive biomarker for head and neck squamous cell carcinoma

BACKGROUND

The main purpose of this study was to validate the prognostic significance of tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) in head and neck squamous cell carcinoma (HNSCC) using an independent cohort.

METHODS

Data were evaluated from 153 patients with HNSCC in stages III to IV, who received radiotherapy (RT) or chemoradiotherapy. We quantified soluble TWEAK (sTWEAK) in pretreatment samples using enzyme-linked immunosorbent assay.

RESULTS

The classification tree revealed a cutoff value of 322 pg/mL for sTWEAK to be ideal for discriminating between patients' disease control. Kaplan-Meier curves indicate that the disease-free survival rate in patients with high sTWEAK was significantly higher than in patients with low levels (p = .006, log-rank test). An independent link was identified between low sTWEAK and poor clinical outcome in Cox regression multivariate analysis (hazard ratio = 1.866; 95% confidence interval [CI] = 1.114-3.125; p = .001).

CONCLUSION

Our study highlights the significance of this noninvasive biomarker in the discrimination according to the disease control achieved by patients who received a nonsurgical organ-preservation treatment. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1358-E1363, 2016.

Early volume variation of positive lymph nodes assessed by in-room mega voltage CT images predicts risk of loco-regional relapses in head and neck cancer patients treated with intensity-modulated radiotherapy

BACKGROUND

We investigated the possibility to early identify non-responding patients based on FDG-PET positive lymph nodes (PNs) volume variation assessed with in-room images.

MATERIAL AND METHODS

Twenty-seven head and neck cancer patients with at least one pre-treatment PNs were retrospectively analyzed; they received 54 Gy, 66 Gy, 69 Gy in 30 fractions on precautionary lymph nodal (N), primary (T) and PET positive (BTV) planning target volumes (PTVs), respectively with Helical TomoTherapy (SIB approach). PNs volume changes during treatment were assessed based on megavoltage computed tomography (MVCT) used for image guidance as ratio between volumes at fractions 10/20/30 and at first fraction. Data on T, N and M relapses (rT, rN, rM) were collected for all patients. The difference of PNs volume changes, during treatment, between patients with versus without relapses was tested (Mann-Whitney test). The impact of shrinkage on the corresponding survival curves (Cox proportional-hazard regression), dividing between no/moderate versus large shrinkage (based on ROC curve best cut-off value) was also investigated.

RESULTS

Median follow-up was 27.4 m (3.7-108.9). The numbers for rT, rN, rM were 5, 4, 6, respectively. Differences in PNs shrinkage were found between patients with and without rT/rN at all considered timing [fr 20, rT: 0.56 vs. 1.07 (median), p = 0.06; rN: 0.57 vs. 1.25, p = 0.07]. Differences were lower for rM. Survival curves provide high hazard ratios (HR) between PNs changes and rT/rN at all considered timing [fr 20, rT: best cut-off = 0.58, HR 5.1 (95% CI 0.5-49.4), p = 0.12; rN: best cut-off = 0.98, HR 14.9 (1.6-142.9), p = 0.01].

CONCLUSION

A limited shrinkage of PNs during treatment is associated with poorer outcome in terms of T/N relapses. The early variation of PNs observed on in-room images may provide useful information about the individual response with potential application in guiding an early adaptation of the treatment.

Predicting oropharyngeal tumor volume throughout the course of radiation therapy from pretreatment computed tomography data using general linear models

PURPOSE

The purpose of this work was to develop and evaluate the accuracy of several predictive models of variation in tumor volume throughout the course of radiation therapy.

METHODS

Nineteen patients with oropharyngeal cancers were imaged daily with CT-on-rails for image-guided alignment per an institutional protocol. The daily volumes of 35 tumors in these 19 patients were determined and used to generate (1) a linear model in which tumor volume changed at a constant rate, (2) a general linear model that utilized the power fit relationship between the daily and initial tumor volumes, and (3) a functional general linear model that identified and exploited the primary modes of variation between time series describing the changing tumor volumes. Primary and nodal tumor volumes were examined separately. The accuracy of these models in predicting daily tumor volumes were compared with those of static and linear reference models using leave-one-out cross-validation.

RESULTS

In predicting the daily volume of primary tumors, the general linear model and the functional general linear model were more accurate than the static reference model by 9.9% (range: -11.6%-23.8%) and 14.6% (range: -7.3%-27.5%), respectively, and were more accurate than the linear reference model by 14.2% (range: -6.8%-40.3%) and 13.1% (range: -1.5%-52.5%), respectively. In predicting the daily volume of nodal tumors, only the 14.4% (range: -11.1%-20.5%) improvement in accuracy of the functional general linear model compared to the static reference model was statistically significant.

CONCLUSIONS

A general linear model and a functional general linear model trained on data from a small population of patients can predict the primary tumor volume throughout the course of radiation therapy with greater accuracy than standard reference models. These more accurate models may increase the prognostic value of information about the tumor garnered from pretreatment computed tomography images and facilitate improved treatment management.

The role of tumor volume in radiotherapy of patients with head and neck cancer

The assumption that the larger tumor contains a higher number of clonogenic cells what may deteriorate prognosis of patients treated with RT has been confirmed in many clinical studies. Significant prognostic influence of tumor volume (TV) on radiotherapy (RT) outcome has been found for tumors of different localizations including patients with head and neck cancer (HNC). Although TV usually is a stronger prognostic factor than T stage, commonly used TNM classification system dose not incorporate TV data. The aim of the paper is to refresh clinical data regarding the role of TV in RT of patients with HNC. At present somehow new meaning of TV could be employed in the aspect of modern RT techniques and combined treatment strategies. For larger TV more aggressive treatment options may be considered. In modern RT techniques escalated dose could be provided highly conformal or RT can be combined with systemic treatment increasing therapeutic ratio. In the study several reports estimating prognostic value of TV for patients with HNC treated with RT has been reviewed.Due to substantially various reported groups of patients as to tumor site, stage of disease or treatment strategies, precise cut-off value could not be establish in general, but the significant association between TV and treatment outcome had been found in almost all studies. There is a strong suggestion that TV should supplement clinical decision in the choice of optimal treatment strategy for patients with HNC.

Impact of primary tumor volume on local control after definitive radiotherapy for head and neck cancer

BACKGROUND

The impact of primary tumor volume (pTV) on local control after definitive radiotherapy (RT) for head and neck squamous cell carcinoma (HNSCC) is unclear.

METHODS

Pertinent literature was reviewed to address the impact of pTV on local control after definitive RT for HNSCC.

RESULTS

Reproducibility of pTV calculations is probably influenced by interobserver variability and may be reduced by relying on experienced observers. The impact of pTV on local control after definitive RT is probably influenced by primary site. A relatively limited impact of pTV on local control after RT for oropharyngeal squamous cell carcinomas (SCCs) might be attributable to human papillomavirus (HPV) positivity.

CONCLUSION

pTV may be a useful parameter to select patients for treatment with definitive RT, particularly for those with laryngeal SCCs. Patients with high-volume primary cancers, in which the probability of local control with a functional larynx is low, are likely better treated with surgery.

Volumetric stratification of cT4 stage head and neck cancer

BACKGROUND

Locoregionally advanced stage head and neck cancer (HNC) is known for unfavorable outcome with only ~ 40-50% 3-year overall survival (OS). Clinical T4 stage includes a wide range of tumor burden. The lack of further nonsurgical subgrouping of cT4 stage makes intercenter outcome of irradiated cohorts difficult. Aim of this analysis was to further stratify cT4 stage HNC using volumetric staging.

MATERIAL AND METHODS

Between January 2002 and January 2013, a total of 201 cT4 stage squamous cell cancer (SCC) HNC patients referred to our center for curative definitive radiation were consecutively irradiated. Radiation was performed using modulated techniques. Total gross tumor volumes (tGTV: primary+nodal tumor volume) of all patients have retrospectively been stratified using a prospectively evaluated volumetric staging system which bases on 3 cut-offs (15/70/130 ml), translating into 4 prognostic subgroups [V1: 1-15 ml (n=15), V2: 16-70 ml (108), V3: 71-130 ml (62), V4: >130 ml (16)]. OS, disease-free survival (DFS), locoregional control (LRC), and distant metastasis-free survival (DMFS) rates were calculated.

RESULTS

The mean/median follow-up was 31/23 months (range 1-116 months). The 3-year OS, DFS, LRC, and DMFS rates of the entire cohort were 63, 44, 48, and 77%, respectively. Volumetric staging revealed its potential to prognostically statistically significantly divide the cT4 cohort into 4 volume subgroups (V1/2/3/4): OS: 90%/72%/58%/18%; DFS: 83%/50%/39%/10%; LRC: 81%/53%/47%/15%; DMFS: 93%/90%/70%/41%, all p<0.0001.

CONCLUSION

Volumetric staging allowed a highly statistically significant stratification of cT4 HNC stages into prognostic subgroups, which offers the chance of better intercenter comparability of irradiated advanced stage HNC cohorts.

Dynamic contrast-enhanced MR imaging predicts local control in oropharyngeal or hypopharyngeal squamous cell carcinoma treated with chemoradiotherapy

The role of pretreatment dynamic contrast-enhanced perfusion MR imaging (DCE-PWI) and diffusion-weighted MR imaging (DWI) in predicting the treatment response of oropharyngeal or hypopharyngeal squamous cell carcinoma (OHSCC) to chemoradiation remains unclear. We prospectively investigated the ability of pharmacokinetic parameters derived from pretreatment DCE-PWI and DWI to predict the local control of OHSCC patients treated with chemoradiation. Between August, 2010 and March, 2012, patients with untreated OHSCC scheduled for chemoradiation were eligible for this prospective study. DCE-PWI and DWI were performed in addition to conventional MRI. The relationship of local control with the following clinical and imaging variables was analyzed: the hemoglobin level, T-stage, tumor location, gross tumor volume, maximum standardized uptake value, metabolic tumor volume and total lesion glycolysis on FDG PET/CT, transfer constant (K^trans), volume of blood plasma and volume of extracellular extravascular space on DCE-PWI, and apparent diffusion coefficient on DWI of the primary tumor. The patients were also divided into a local control group and a local failure group, and their clinical and imaging parameters were compared. There were 58 patients (29 with oropharynx squamous cell carcinoma [SCC] and 29 with hypopharynx SCC) with successful pretreatment DCE-PWI and DWI available for analysis. After a median follow-up of 18.2 months, 17 (29.3%) participants had local failure, whereas the remaining 41 patients achieved local control. Univariate analysis revealed that only the K^trans value was significantly associated with local control (P = 0.03). When the local control and local failure groups were compared, significant differences were observed in K^trans and the tumor location (P = 0.01 and P = 0.04, respectively). In the multivariable analysis, only K^trans was statistically significant (P = 0.04). Our results suggest that pretreatment K^trans may help predict the local control in OHSCC patients treated with chemoradiation.

Tumor volume reduction rate measured during adaptive definitive radiation therapy as a potential prognosticator of locoregional control in patients with oropharyngeal cancer

BACKGROUND

The purpose of this study was to evaluate the prognostic significance of the tumor volume reduction rate (TVRR) measured during adaptive definitive radiation therapy (RT) in patients with oropharyngeal cancer.

METHODS

We reviewed the RT records of 59 patients with oropharyngeal cancer who were treated with definitive RT with or without concurrent chemotherapy between January 2006 and October 2010. Adaptive replanning was performed in all patients during RT. The pre-RT and mid-RT gross tumor volumes (GTVs) of the primary and the metastatic lymph nodes were measured and analyzed for their possible impacts on locoregional control.

RESULTS

After the median follow-up period of 41.3 months (range, 9.3-73.5 months) for survivors, there were 10 treatment failures (8 locoregional recurrences and 2 distant metastases). The locoregional control rate at 3 years in all the patients was 84.1%. The mean pre-RT and mid-RT total GTVs were 27.5 cm(3) (±17.9 cm(3) ) and 16.9 cm(3) (±12.1 cm(3) ), and the mean GTV reduction rate was 37.9% (±22.6%), respectively. The patients who achieved locoregional control had a higher TVRR than those with locoregional failure (p = .010), and those with the TVRR >35% achieved significantly higher locoregional control at 3 years (94.4% vs 72.4%; p = .018). On multivariate analysis when adjusted with other clinical prognostic factors, the TVRR was found to be a significant factor affecting the locoregional control (hazard ratio = 0.136; 95% confidence interval = 0.022-0.852; p = .033).

CONCLUSION

The TVRR measured during adaptive RT proved a significant prognosticator on locoregional disease control in patients with oropharyngeal cancer, based on which a few therapeutic modifications may be considered.

Predicting recurrence after radiotherapy in head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Radiotherapy is a mainstay of treatment, either alone for early stage tumors or combined with chemotherapy for late stage tumors. An overall 5-year survival rate of around 50% for HNSCC demonstrates that treatment is often unsuccessful. Prediction of outcome is, therefore, aimed at sparing patients from ineffective and toxic treatments on the one hand, and indicating more successful treatment modalities on the other. Both functional and genetic assays have been developed to predict intrinsic radiosensitivity, hypoxia, and repopulation rate. Few, however, have shown consistent correlations with outcome across multiple studies. Messenger RNA and microRNA profiling show promise for predicting hypoxia, whereas epidermal growth factor receptor expression combined with other measures of tumor differentiation grade shows promise for predicting repopulation rate. Intrinsic radiosensitivity assays have not proven useful to date, although development of repair protein foci assays indicates promise from preclinical studies. Assays for cancer stem cell content have shown promise in several clinical studies. In addition, 2 assays showing robustness as predictors for outcome in HNSCC are human papilloma virus status and epidermal growth factor receptor expression. Neither these nor stem cell assays, however, can as yet reliably indicate alternative and better treatments for poor prognosis patients. It would be of great value to have assays that predict the benefit for an individual from combining new molecularly targeted agents with radiotherapy to increase response, in particular those that exploit tumor mutations to provide tumor specificity. Predictive assays are being developed for detecting defects in repair pathways for single- and double-strand DNA breaks, which should allow selection of drugs targeting the appropriate backup pathway, thus exploiting the concept of synthetic lethality. This is one of the most promising areas for prediction, both currently and in the future.

The value of tumor diameter in predicting prognosis of oropharynx cancer treated with chemoradiation

OBJECTIVES

The tumor node metastasis (TNM) system is the most widely used staging system for cancers of the oropharynx, yet is known to omit key prognostic indicators. Tumor volume has been shown in other head and neck sites to add predictive power but is not as useful in the oropharynx. This study investigates the value of other methods in quantifying tumor burden.

METHODS

Treatment plans of oropharyngeal cancer patients treated non-operatively were retrospectively reviewed. Potential prognostic factors including TNM, demographics, smoking history, and various tumor dimensions were analyzed.

RESULTS

Records identified 93 patients treated with definitive concurrent chemoradiation who had at least one year of follow-up and a clear GTV contour on the original treatment plan. On univariate analysis, tumor diameter and tumor volume showed a significant relationship to overall and disease-free survival. Tumor stage, age and smoking history showed significance in regard to overall survival. On multivariate analysis tumor diameter showed independent significance but not TNM or tumor volume.

CONCLUSION

Our method of measuring tumor diameter has independent prognostic significance in the oropharynx where GTV has shown questionable value.

Definitive Radiotherapy versus Postoperative Radiotherapy of Patients with Oro- and Hypopharyngeal Cancer: Impact of Prognostic Factors

Purpose. To compare the impact of prognostic factors of patients treated with definitive radio(chemo)therapy versus patients treated with surgery and postoperative radiotherapy for squamous cell carcinoma of the oro- and hypopharynx. Patients and Methods. 162 patients treated with definitive radiotherapy and 126 patients treated with postoperative radiotherapy were retrospectively analysed. The impact of the prognostic factors gender, age, total tumor volume (TTV), pre-radiotherapy hemoglobin level (Hb-level), tumor site, T- and N-classification, radiotherapy interruptions >5 days, radiotherapy versus simultaneous radiochemotherapy, R-status and time interval between surgery and radiotherapy were investigated. Results. The median follow-up time for the censored patients treated with definitive radio(chemo)therapy was 28.5 months and for postoperative radiotherapy 36.5 months. On univariate analysis, the TTV, Hb-level, and simultaneous radiochemotherapy had a significant impact on the survival of patients treated with definitive radio(chemo)therapy. For patients treated with postoperative radiotherapy, only the TTV showed a statistical trend for the survival (P = 0.13). On multivariate analysis, the TTV and simultaneous radiochemotherapy maintained their statistical significance for patients treated with definitive raditherapy, and the TTV, the statistical trend for patients treated with postoperative radiotherapy (P = 0.19). Conclusions. The TTV was the predominant prognostic factor for both, patients treated with definitive or postoperative radiotherapy.

Intensity-modulated radiation therapy in oropharyngeal carcinoma: effect of tumor volume on clinical outcomes

PURPOSE

To analyze the effect of primary gross tumor volume (pGTV) and nodal gross tumor volume (nGTV) on treatment outcomes in patients treated with definitive intensity-modulated radiation therapy (IMRT) for oropharyngeal cancer (OPC).

METHODS AND MATERIALS

Between September 1998 and April 2009, a total of 442 patients with squamous cell carcinoma of the oropharynx were treated with IMRT with curative intent at our center. Thirty patients treated postoperatively and 2 additional patients who started treatment more than 6 months after diagnosis were excluded. A total of 340 patients with restorable treatment plans were included in this present study. The majority of the patients underwent concurrent platinum-based chemotherapy. The pGTV and nGTV were calculated using the original clinical treatment plans. Cox proportional hazards models and log-rank tests were used to evaluate the correlation between tumor volumes and overall survival (OS), and competing risks analysis tools were used to evaluate the correlation between local failure (LF), regional failure (RF), distant metastatic failure (DMF) vs. tumor volumes with death as a competing risk.

RESULTS

Median follow-up among surviving patients was 34 months (range, 5-67). The 2-year cumulative incidence of LF, RF and DF in this cohort of patients was 6.1%, 5.2%, and 12.2%, respectively. The 2-year OS rate was 88.6%. Univariate analysis determined pGTV and T-stage correlated with LF (p < 0.0001 and p = 0.004, respectively), whereas nGTV was not associated with RF. On multivariate analysis, pGTV and N-stage were independent risk factors for overall survival (p = 0.0003 and p = 0.0073, respectively) and distant control (p = 0.0008 and p = 0.002, respectively).

CONCLUSIONS

In this cohort of patients with OPC treated with IMRT, pGTV was found to be associated with overall survival, local failure, and distant metastatic failure.

Can FDG PET predict radiation treatment outcome in head and neck cancer? Results of a prospective study

Purpose

In head and neck cancer (HNC) various treatment strategies have been developed to improve outcome, but selecting patients for these intensified treatments remains difficult. Therefore, identification of novel pretreatment assays to predict outcome is of interest. In HNC there are indications that pretreatment tumour ¹⁸F-fluorodeoxyglucose (FDG) uptake may be an independent prognostic factor. The aim of this study was to assess the prognostic value of FDG uptake and CT-based and FDG PET-based primary tumour volume measurements in patients with HNC treated with (chemo)radiotherapy.

Methods

A total of 77 patients with stage II–IV HNC who were eligible for definitive (chemo)radiotherapy underwent coregistered pretreatment CT and FDG PET. The gross tumour volume of the primary tumour was determined on the CT (GTV_CT) and FDG PET scans. Five PET segmentation methods were applied: interpreting FDG PET visually (PET_VIS), applying an isocontour at a standardized uptake value (SUV) of 2.5 (PET_2.5), using fixed thresholds of 40% and 50% (PET_40%, PET_50%) of the maximum intratumoral FDG activity (SUV_MAX) and applying an adaptive threshold based on the signal-to-background (PET_SBR). Mean FDG uptake for each PET-based volume was recorded (SUV_mean). Subsequently, to determine the metabolic volume, the integrated SUV was calculated as the product of PET-based volume and SUV_mean. All these variables were analysed as potential predictors of local control (LC), regional recurrence-free survival (RRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS) and overall survival (OS).

Results

In oral cavity/oropharynx tumours PET_VIS was the only volume-based method able to predict LC. Both PET_VIS and GTV_CT were able to predict DMFS, DFS and OS in these subsites. Integrated SUVs were associated with LC, DMFS, DFS and OS, while SUV_mean and SUV_MAX were not. In hypopharyngeal/laryngeal tumours none of the variables was associated with outcome.

Conclusion

There is no role yet for pretreatment FDG PET as a predictor of (chemo)radiotherapy outcome in HNC in daily routine. However, this potential application needs further exploration, focusing both on FDG PET-based primary tumour volume, integrated SUV and SUV_MAX of the primary tumour.

Pretreatment prognostic factors of survival in patients with locally advanced nonmetastatic squamous cell carcinoma of the head and neck treated with radiation therapy with or without concurrent chemotherapy

BACKGROUND

Identification of pretreatment prognostic factors influencing overall survival (OS) in locally advanced squamous cell carcinoma of the head and neck is an important issue in head and neck oncology.

METHODS

A total of 289 patients were treated with standard fraction or hyperfractionated radiation therapy with or without concurrent low-dose daily chemotherapy.

RESULTS

Gender (P = 0.43) and age (P = 0.26) did not influence OS whereas Karnofsky Performance Status (KPS) (P < 0.0001), T stage (P < 0.0001), and N stage (P < 0.0001) did. Stage grouping was another factor that influenced OS (P < 0.001). Patients with larynx and nasopharynx fared better than those with other primaries (P = 0.0153). Finally, treatment significantly influenced OS. Multivariate analysis showed that KPS, T and N stage, and treatment were independent prognosticators of OS.

CONCLUSIONS

KPS, T and N stage, and treatment are independent prognosticators of OS in patients with locally advanced squamous cell carcinoma of the head and neck treated with radiation therapy with or without concurrent low-dose daily chemotherapy.

Volumetric staging (VS) is superior to TNM and AJCC staging in predicting outcome of head and neck cancer treated with IMRT

The UICC classification (TNM) represents the validated standard tool to describe tumor extent and includes prognostic information on the probability of disease control. The American Joint Committee on Cancer (AJCC) stage grouping is based on the evaluation of treatment and outcome. Gross tumor volume (GTV) might be more relevant than pure description (TNM) or stage grouping as prognostic factor for local control in head and neck cancer (HNC). Based on the observation of GTV-correlated outcome in our initial HNC patient cohort treated with IMRT, we tested the hypothesis that the GTV is the most reliable predictive tool in HNC outcome. A GTV based volumetric staging system (VS) was introduced, using two volumetric cut-off values (15 and 70 cm3). VS, TNM, and AJCC stages were assessed and correlated with outcome following primary radiation in 172 HNC patients. Analyses were based on Kaplan-Meier survival curves. VS proved to be superior to the TNM/AJCC in predicting outcome. In addition, VS enabled to stratify high- and low-risk patients in advanced TN stages. GTV represented the most important prognostic indicator in HNC treated with IMRT and is recommended to be considered for therapeutic decisions and estimation of outcome.

Response and progression-free survival in oropharynx squamous cell carcinoma assessed by pretreatment perfusion CT: comparison with tumor volume measurements

BACKGROUND AND PURPOSE

Perfusion CT (PCT) provides a rapid, reliable, and non-invasive technique for assessing tumor vascularity. The purpose of this study was to assess whether pretreatment dynamic perfusion CT (PCT) may predict response to induction chemotherapy and midterm progression-free survival (PFS) in advanced oropharynx squamous cell carcinoma (SCCA) and to compare the results with those derived by tumor volume measurements.

MATERIALS AND METHODS

Nineteen patients underwent routine contrast-enhanced CT (CECT), pretreatment PCT, and conventional endoscopy. Tumor response was determined according to radiologic (RECIST) criteria. The PCT parameters, tumor volume, radiologic response, and PFS were analyzed with use of Cox-proportional hazards model, receiver operating characteristic (ROC), and Kaplan-Meier analysis.

RESULTS

The baseline blood flow (BF), blood volume (BV), and permeability surface area product (PS) were significantly higher, whereas mean transit time (MTT) was significantly lower in the responders than in the nonresponders (P < or = .002). BV showed 100% sensitivity, MTT and PS had the highest specificity (100%), and BF showed 84.2% sensitivity and 66.7% specificity for prediction of tumor response after induction chemotherapy. The pretreatment tumor volume correlated with PFS in the pooled patients group (r = 0.4; P < .0001), whereas postinduction tumor volume correlated significantly with PFS in the responders and nonresponders (r = 0.22-0.64; P < or = .006). Pretreatment tumor volume (P = .0001) and BF (P = .001) were significant predictors for PFS.

CONCLUSIONS

Pretreatment PCT parameters may predict response after induction chemotherapy. Tumor volume and BF values may predict PFS in patients with advanced oropharyngeal SCCA.

An evaluation of the variability of tumor-shape definition derived by experienced observers from CT images of supraglottic carcinomas (ACRIN protocol 6658)

PURPOSE

Accurate target definition is considered essential for sophisticated, image-guided radiation therapy; however, relatively little information has been reported that measures our ability to identify the precise shape of targets accurately. We decided to assess the manner in which eight "experts" interpreted the size and shape of tumors based on "real-life" contrast-enhanced computed tomographic (CT) scans.

METHODS AND MATERIALS

Four neuroradiologists and four radiation oncologists (the authors) with considerable experience and presumed expertise in treating head-and-neck tumors independently contoured, slice-by-slice, his/her interpretation of the precise gross tumor volume (GTV) on each of 20 sets of CT scans taken from 20 patients who previously were enrolled in Radiation Therapy Oncology Group protocol 91-11.

RESULTS

The average proportion of overlap (i.e., the degree of agreement) was 0.532 (95% confidence interval 0.457 to 0.606). There was a slight tendency for the proportion of overlap to increase with increasing average GTV.

CONCLUSIONS

Our work suggests that estimation of tumor shape currently is imprecise, even for experienced physicians. In consequence, there appears to be a practical limit to the current trend of smaller fields and tighter margins.

Head and neck cancer: how imaging predicts treatment outcome

Sophisticated imaging methods, such as computed tomography, magnetic resonance imaging and positron emission tomography, play an increasingly important role in the management of head and neck cancer. Pretreatment imaging findings have predictive value for patient outcome, independently from the currently used TNM classification, and may be used to tailor treatment to the individual patient. Based on per-treatment imaging, individualised replanning during radiotherapy may ameliorate tumour control rates and reduce toxic effects to normal tissues. Early posttreatment imaging studies contain important prognostic information, and allow selection of patients for further treatment or watchful waiting.

Reassessment of the role of induction chemotherapy for head and neck cancer

Head and neck cancers are a complex group of diseases defined by variations in histological features, anatomical location, and cause. Once the realm of surgeons and radiation oncologists, the treatment of locally advanced disease now involves medical oncologists. Major developments include primary chemoradiotherapy for unresectable disease and organ preservation, the addition of chemotherapy to adjuvant radiotherapy, improvement in surgical and radiation techniques, and biological therapies. Concomitant chemoradiotherapy consistently improves locoregional control. However, control of distant metastases is poor, resulting in an increasing proportion of deaths from systemic recurrence. Given this shift in site of recurrence, therapeutic strategies to suppress distant metastases may be the next goal for further improvement of survival. One approach that merits reassessment is the use of induction chemotherapy in the setting of locally advanced disease--both resectable and unresectable. In this review we summarise data for the use of induction chemotherapy to define better which patients will likely benefit from this approach now and which questions are important in the design of future clinical trials.

Prognostic influence of retropharyngeal lymph node metastasis in squamous cell carcinoma of the oropharynx

PURPOSE

To investigate the impact of involvement of retropharyngeal lymph nodes on the prognosis of squamous cell carcinoma of the oropharynx.

METHODS AND MATERIALS

The pretreatment computed tomographic scans of 208 patients with squamous cell carcinoma of the oropharynx were reviewed for the presence of metastatic retropharyngeal lymph nodes. All patients were treated at the Leuven department between 1984 and 2003: by radiotherapy alone in 84.1% of patients, by surgery with postoperative radiotherapy in 11.5%, and by concomitant chemoradiotherapy in 4.4%. Retropharyngeal node involvement was present in 34 (16%) patients. The influence on recurrence (local and regional), distant metastasis, and survival was retrospectively analyzed. Median follow-up was 47 months (3.9 years), and results were analyzed for 201 patients.

RESULTS

At 5 years, patients with retropharyngeal adenopathy had significantly more regional recurrences (45% vs. 10%, p = 0.004). Involvement of retropharyngeal lymph nodes significantly (relative risk 4.29 [95% confidence interval 3.33-5.25], p = 0.01) and independently predicted regional recurrence in multivariate analysis. Disease-specific survival was significantly lower in the retropharyngeal node positive group (38% vs. 58%, p = 0.03).

CONCLUSIONS

Retropharyngeal node involvement has a negative impact on the prognosis of squamous cell cancer of the oropharynx. Patients are particularly at risk for regional recurrence, resulting in worse disease-specific survival. Retropharyngeal node involvement should be taken into account in designing the treatment plan for these patients.

Radical Radiotherapy in Head and Neck Squamous Cell Carcinoma: An Analysis of Prognostic and Therapeutic Factors

AIMS

Head and neck squamous cell carcinoma (HNSCC) continues to be a leading cancer in developing countries. Definitive radiation therapy either primary or as postoperative adjuvant is offered to most patients. We aimed to identify prognostic and therapeutic factors that affect locoregional control and survival in patients undergoing radical radiotherapy for head and neck squamous cell cancers.

MATERIALS AND METHODS

A retrospective analysis of 568 previously untreated patients with squamous head and neck cancers, who received radical radiotherapy between 1990 and 1996, using local control, locoregional control and disease-free survival (DFS) as outcome measures.

RESULTS

With a median follow-up of 18 months for living patients, the 5-year local control, locoregional control and DFS for all 568 patients were 53%, 45% and 41%, respectively, for all stages combined. The 5-year local control, locoregional control and DFS as per the American Joint Committee on Cancer stage grouping were 78%, 70% and 70%; 64%, 59% and 57%; 51%, 42% and 37%; and 40%, 27% and 22% from stages I to IV, respectively, with highly significant P values. Patients receiving higher doses (> or = 66 Gy) had a significantly better outcome compared with lower doses. The 5-year local control (59% vs 48%, P = 0.0015), locoregional control (47% vs 41%; P = 0.0043) and DFS (44% vs 37%; P = 0.0099) were significantly better in patients receiving > or = 66 Gy. Site of primary also affected outcome significantly, with oral cavity lesions faring badly.

CONCLUSION

Tumour stage remains the most important factor affecting outcome in radical radiotherapy of HNSCC. A definite dose-response relationship exists with higher total doses, leading to better local control, locoregional control and DFS in all stages. Site of primary affects outcome too, with laryngeal primaries doing well and oral cavity cancers faring the worst.

What the clinician wants to know: surgical perspective and ultrasound for lymph node imaging of the neck

Imaging of lymph node metastases in the neck can have two major indications: (1) prognosis and assisting with choice of treatment; (2) staging and detection of clinically occult metastases in different levels of the neck. Both indications are discussed. The role and limitations of US and US-guided fine-needle aspiration cytology are also reviewed.

Predictive factors of local-regional recurrences following parotid sparing intensity modulated or 3D conformal radiotherapy for head and neck cancer

BACKGROUND AND PURPOSE

Predictive factors for local-regional (LR) failures after parotid-sparing, Intensity modulated (IMRT) or 3D conformal radiotherapy for head and neck (HN) cancers were assessed.

PATIENTS AND METHODS

One hundred and fifty-eight patients with mostly stages III-IV HN squamous cell carcinoma underwent curative bilateral neck irradiation aimed at sparing the parotid glands. Patient, tumor, and treatment factors were analyzed as predictive factors for LR failure.

RESULTS

Twenty-three patients had LR recurrence (19 in-field and four marginal). No differences were found in the doses delivered to the PTVs of patients with or without in-field recurrences. In univariate analysis, tumor site was highly predictive for LR failure in both postoperative and definitive RT patients. In postoperative RT patients, pathologic tumor size, margin status, extracapsular extension (ECE) and number of lymph node metastases, were also significantly predictive. Multivariate analysis showed tumor site (oropharynx vs. other sites) to be a significant predictor in all patients, and involved margins and number of involved lymph nodes in postoperative patients.

CONCLUSIONS

Clinical rather than dosimetric factors predicted for LR failures in this series, and were similar to those reported following standard RT. These factors may aid in the selection of patients for studies of treatment intensification using IMRT.

Impact of tumor control and presence of visible necrosis in head and neck cancer patients treated with radiotherapy or radiochemotherapy

PURPOSE

Tumor volume after the lymph node involvement is one of the most important single prognostic factor in patients of head and neck cancers treated with radiotherapy. We have recently demonstrated that the hypoxic subvolume is more important than the total tumor volume. We therefore propose the hypothesis that the presence of visible necrosis might be an important factor for cure by radiotherapy in squamous cell cancers of the head and neck.

METHODS

A total of 51 patients with locally advanced inoperable (T3-4 or N2-3) squamous cell cancers of the head and neck (mean age 57 years, range 41-75 years) were prospectively investigated with regard to a possible impact of tumor volume. All patients received CT examination of the head and neck according to a standardized protocol (spiral CT, contrast enhancement after automatic injection), and the total tumor volume was calculated as the sum of volumes of all visible macroscopic tumor sites. Poorly perfused and necrotic areas (no contrast enhancement) within macroscopic tumor sites were also calculated. Patients were then treated with accelerated-hyperfractionated radiotherapy in about 6 weeks. Seventeen patients were treated with only radiation. Patients without contraindications to cisplatin chemotherapy received cisplatin chemotherapy or a combination of cisplatin and paclitaxel (N=34). The allocation of patients to certain treatment regimens was based on individual decisions in each case and not randomized.

RESULTS

In patients treated with radiation alone, 12/17 (71%) got recurrence whereas in patients treated with radiation plus cisplatin, only 14/34 (41%) recurred (P=0.05). The 2-year overall survival was for radiation alone versus radiation plus cisplatin 0% vs. 62% (P<0.0008). Tumors with smaller amount of necrosis (necrosis volume<4 cm3) had a good prognosis irrespective of type of treatment (radiation alone or radiation plus cisplatin). However, patients with tumors with a larger amount of necrosis (necrosis volume> or =4 cm3) had a significantly better outcome if they were treated with radiation plus cisplatin as compared to patients treated with radiation alone. In a multi-variate analysis using a Cox-regression model the type of treatment (radiotherapy plus versus without cisplatin) was the only independent prognostic factor for event-free survival (P<0.03) in the whole group.

CONCLUSIONS

In this non-randomized retrospective investigation with limited sample size, radiation plus cisplatin was superior to radiation alone. This resulted mainly from a higher efficacy of the radiochemotherapy regimen in patients with large and especially necrotic tumors. The prognostic and predictive impact of visible necrosis should be further evaluated.

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.

CT-based analysis of malignant tumor volume and localization: a preliminary study

The purpose of this study was to correlate 3D-CT (3D computed tomography) volume measurements of malignant tumors with the response to treatment, and to observe bone invasion in these lesions applying a specific imaging protocol. We analyzed 17 individuals with maxillofacial malignant lesions who were submitted to spiral CT (2D-CT). The original data were transferred to an independent workstation using a 3D volume rendering package software, which was used by two examiners to obtain area and volume measurements of the lesions, independently, three times each, prior to and after treatment. The segmentation protocol was applied for the assessment of bone involvement. The difference between imaging and gold standard values was not considered significant (p > 0.05). Regarding bone invasion, three false-negatives were obtained using MPR-CT (multiplanar reconstruction) and no false-negatives were obtained using the 3D segmentation protocol. The use of 3D-CT may be a differential and important factor for expanding options regarding the localization, dimension, and clarification of lesion components.

Semi-quantitative assessment of oral cavity squamous cell carcinoma using201 TI SPECT for evaluating effectiveness of preoperative radiotherapy

The aim of this study is to reveal the usefulness of semi-quantitative assessment using 201Tl chloride (Tl) single photon emission computed tomography (SPECT) (Tl SPECT) to evaluate the effectiveness of radiotherapy in 15 patients with oral cavity squamous cell carcinma (SCC). Fifteen patients were diagnosed with SCC by biopsy. All 15 patients enrolled in this study were planned to undergo preoperative radiotherapy with or without chemotherapy using carboplatin (CBDCA) and received reduction operation. Tl SPECTs were performed 15 minutes after intravenous administration of 111 MBq 201Tl chloride. Regions of Interest (ROI) were set up around tumor (T), and non-lesion (N) at the part of contralateral scalp at the height of the cerebellum. The ratios of mean counts in ROI of the tumor to those in non-lesion were measured as pre- and post-treatment T/N ratios (pre T/N, post T/N). Furthermore, reduction rate (RR) was obtained by calculating [(pre T/N - post T/N)/(pre T/ N)] x 100%. Each parameter (pre T/N, post T/N, and RR) was compared to histopathological grade of surgical specimen based on the Oboshi and Shimosato classification (grade I-IV). RR showed significantly higher values in grade III and IV than in grade I and II (p = 0.0008). In conclusion, semi-quantitative assessment using Tl SPECT, especially calculating RR, is useful to evaluate the effectiveness of preoperative radiotherapy.

Prognostic impact of tumor volumetry in patients with locally advanced head-and-neck carcinoma (non-nasopharyngeal) treated by radiotherapy alone or combined radiochemotherapy in a randomized trial

PURPOSE

Tumor volume (TV) is one of the main reported factors determining the outcome of treatment in head-and-neck carcinomas. In this study, the prognostic impact of TV was explored in the context of a randomized trial with the patients assigned to receive standard radiotherapy (RT) alone or RT plus platinum compounds (RT alone, RT plus cisplatin, or RT plus carboplatin).

METHODS AND MATERIALS

The tumor outlines were traced and digitized on each pretreatment CT slice for each of the 101 patients studied. Taking into account the magnification factor of the scan and CT slice thickness, a computer with specifically designed software calculated the TV in cubic centimeters.

RESULTS

The median overall survival for the whole group of patients was 21.6 months (95% confidence interval, 13.0-30.2) and the 3-year survival rate was 40%. The addition of platinum compounds to RT (Groups 2 and 3) significantly improved the survival rate (RT alone vs. RT plus cisplatin, hazard ratio 0.36, p = 0.002; RT alone vs. RT plus carboplatin, hazard ratio 0.53, p = 0.029). In univariate analysis, the most significant parameters for survival were treatment group, total gross tumor volume (TGTV), complete response, nodal GTV, primary GTV, and performance status. In multivariate analysis, treatment group, TGTV, gender, and primary site were independent prognostic factors for survival. A prognostic threshold of 22.8 cm(3) was detected for TGTV. Patients with a TGTV of <22.8 cm(3) were more likely to achieve a complete response and had a median survival of 45.3 months, and those with a TGTV >22.8 cm(3) had a median survival of 12.3 months (log-rank test, p = 0.0102).

CONCLUSION

The prognostic significance of the TGTV was confirmed and a cutoff value of 22.8 cm(3) derived. Our data indicated that locally advanced head-and-neck carcinomas should not be treated by standard (once-daily) RT alone. Tumor size and disease subsite should be taken into account in future randomized trials to increase their statistical power.

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.

Tumor volume as determined by computed tomography predicts local control in hypopharyngeal squamous cell carcinoma treated with primary surgery

Computed tomography reliably evaluates hypopharyngeal squamous cell carcinomas (SCC) regarding the infiltration of specific anatomic structures and tumor volumes, both of which have been shown to be predictors of local control in patients treated with radiation therapy alone. However, an association of specific infiltrated structures and/or tumor volume with local control has not been investigated for surgical treatment; thus, we determined relationships of various infiltrated anatomic structures and tumor volume with local control in patients with hypopharyngeal SCC treated with primary surgery. In 45 hypopharyngeal SCC, tumor volumes were measured by pretreatment CT, and extent of tumor infiltration was determined by postoperative pathologic examination. All patients had clinical follow-up for recurrent tumor at the primary site. Statistical analysis basically consisted of chi-square and U-tests. Local control rate was 84.4% (38 of 45). Tumor volume was significantly associated with local control (p=0.004). Six of 16 (38%) patients with tumor volumes > or =8.1 cm3 (mean) had a local recurrence, which is significantly (p=0.003) more compared with 1 of 29 (3%) in the group of patients with volumes <8.1 cm3. Among all evaluated anatomic structures, only a tendency for significant association with local control was found for tumor involvement of the tonsils and the extralaryngeal soft tissues. The determination of tumor volumes by CT helps predict local control in patients with hypopharyngeal SCC treated with primary surgery.

Tumor perfusion rate determined noninvasively by dynamic computed tomography predicts outcome in head-and-neck cancer after radiotherapy

PURPOSE

To investigate the value of CT-determined tumor perfusion as a predictive factor of local and regional failure and cause-specific survival in head-and-neck cancer treated by radiotherapy.

MATERIALS AND METHODS

In 105 patients, the perfusion of a primary head-and-neck squamous cell carcinoma was estimated using dynamic CT. A contrast agent bolus was rapidly injected i.v., while during the first pass a dynamic data acquisition was performed at the level of the largest axial tumor surface. The perfusion in the selected tumor region of interest was calculated by dividing the slope of the tumor-time density curve by the maximal value in arterial density. Primary and nodal tumor volume was calculated from the CT images. All patients were treated by radiotherapy with curative intent; in 15 patients, adjuvant concomitant chemotherapy was administered. Mean follow-up time was 2.2 years. Actuarial (life-table) statistical analysis was done; multivariate analysis was performed using the Cox proportional hazards model.

RESULTS

When the patients were stratified according to the median perfusion value (83.5 mL/min/100 g), those with the lower perfusion rate had a significantly higher local failure rate (p < 0.05). In the multivariate analysis, perfusion rate (p = 0.01) and T category (p = 0.03) were found to be the independent predictors of local failure. Perfusion rate had predictive value regarding neither regional control nor cause-specific survival.

CONCLUSIONS

CT-determined tumor perfusion rate was found to be an independent predictor of local outcome in irradiated head-and-neck cancer. The results of this study confirm the hypothesis that less-perfused tumors respond poorly to radiotherapy.

Parameters that predict local control after definitive radiotherapy for squamous cell carcinoma of the head and neck

PURPOSE

To analyze parameters that may influence the likelihood of local control after definitive radiotherapy for head and neck cancer.

METHODS

Between April 1980 and January 2000, 404 patients were treated with definitive RT alone (358 patients) or combined with adjuvant chemotherapy (46 patients) at our institution and were followed up for 0.25 to 20.25 years (median, 3.5 years.) All living patients were followed up for at least 2 years. All patients had the primary tumor volume calculated on pretreatment CT. End points were local control after RT and local control after RT without a severe late complication. Parameters evaluated in multivariate analyses of these end points included primary site, T stage, primary tumor volume, N stage, histologic differentiation, fractionation schedule, adjuvant chemotherapy, and gender.

RESULTS

The rates of local control and local control without a severe late complication after RT were significantly influenced by primary tumor volume for patients with cancer of the supraglottic larynx and true vocal cord. In contrast, the rates of local control and local control without severe complications for patients with tumors of the oropharynx and hypopharynx were less influenced by tumor volume. Multivariate analysis of the overall population revealed that the only parameter that was significantly related to the probability of local control after RT was T stage. Multivariate analyses stratified by primary site revealed that tumor volume significantly influenced local control for patients with cancers of the supraglottis (p =.0220) and glottis (p =.0042) but not for those with lesions of the tonsillar fossa/posterior tonsillar pillar (p =.0892), base of tongue (p =.9493), anterior tonsillar pillar/soft palate (p =.5909), and hypopharynx (p =.2282).

CONCLUSIONS

The most important parameter that has an impact on local control after RT is T stage. Primary tumor volume also significantly influences the probability of local control in cancers of the supraglottis and glottis.

Altered fractionation and/or adjuvant chemotherapy in definitive irradiation of squamous cell carcinoma of the head and neck

OBJECTIVE

To review the roles of altered fractionation and adjuvant chemotherapy in the treatment of patients with squamous cell carcinomas of the head and neck.

STUDY DESIGN

Review of the pertinent literature.

METHODS

The literature pertaining to altered fractionation and/or adjuvant chemotherapy for patients with squamous cell carcinomas of the head and neck was reviewed to define the optimal combination of radiotherapy and adjuvant chemotherapy.

RESULTS

The efficacy of altered fractionation compared with conventional fractionation depends on the fractionation schedule employed. Some hyperfractionated and accelerated fractionation schedules have resulted in improved locoregional control but no significant improvement in overall survival. In contrast to induction and maintenance chemotherapy, concomitant chemotherapy appears to result in improved locoregional control and survival.

CONCLUSIONS

Altered fractionation and/or concomitant chemotherapy results in improved locoregional control and, in some instances, survival for patients with advanced head and neck cancer. Depending on primary site, the applicability of these aggressive treatment regimens is limited by an enhanced probability of severe complications as tumor volume increases. The optimal combination of these modalities is unclear and will be defined by future prospective trials.

Waiting times for radiotherapy: consequences of volume increase for the TCP in oropharyngeal carcinoma

BACKGROUND AND PURPOSE

Waiting lists for radiotherapy have become longer over the past years. Apart from the psychological distress for the patient we are concerned about tumour growth during this waiting time, which may worsen prognosis. The purpose of this pilot study was to investigate tumour growth in the waiting time and to obtain an indication of its clinical consequences for patients with oropharyngeal carcinoma. A tumour control probability (TCP) model was applied to evaluate consequences for outcome.

METHODS AND MATERIALS

Increase in tumour volume was measured for 13 patients with oropharyngeal carcinoma by outlining the tumour on the diagnostic as well as on the treatment planning CT scan. Waiting time was defined as time between histopathological diagnosis and start of radiotherapy. For each tumour we calculated the increase in tumour volume and the tumour doubling time. The potential increase in TCP was calculated for each tumour for the situation without treatment delay.

RESULTS

The mean increase in tumour volume was 70%. The mean waiting time was 56 days. Expected TCP with incorporation of delay was 47%, without delay it might have been 63-66%.

CONCLUSION

This study shows tumour progression during the time between the diagnostic CT scan and the treatment planning CT scan in oropharyngeal cancer. As a consequence of waiting time, which allows tumour volume increase, there may be an average control loss of 16-19 % for these tumours during the total waiting time before radiotherapy.

The relation of CT-determined tumor parameters and local and regional outcome of tonsillar cancer after definitive radiation treatment

PURPOSE

To investigate the value of CT-derived tumor parameters as predictor of local and regional outcome of tonsillar squamous cell carcinoma treated by definitive radiation therapy.

METHODS AND MATERIALS

The pretreatment CT studies of 112 patients with tonsillar squamous cell carcinoma were reviewed. After redigitizing the films, primary and nodal tumor volume was calculated with the summation-of-areas technique. The nodal CT aspect was graded using a 3-point scale (homogenous, inhomogeneous, and necrotic). Mean follow-up time was 33 months. Actuarial statistical analysis of local and regional outcome was done for each of the covariates; multivariate analysis was performed using Cox's proportional hazards model.

RESULTS

In the actuarial analysis, CT-determined primary tumor volume was significantly correlated with local recurrence rate (p < 0.05) when all patients were considered, but primary tumor volume did not predict local control within the T2, T3, and T4 category. CT-determined nodal volume was significantly related to regional outcome (p < 0.01), but nodal density was not. Total tumor volume was not significantly related to locoregional outcome (p = 0.1). In the multivariate analysis, the T and N categories were the independent predictors of local and regional outcomes, respectively.

CONCLUSION

Compared to other head-and-neck sites, primary and nodal tumor volume have only marginal predictive value regarding local and regional outcome after radiation therapy in tonsillar cancer.