Prognostic value of tumor volumetry data of routine imaging data in a head and neck cancer registry

Prognosticating Gross Tumor Volume in Head-and-Neck Cancer - Redefining Gross Tumor Volume Beyond Contouring

Purpose

Precision radiotherapy (RT) requires accurate delineation of gross tumor volumes (GTVs) for targeted dose delivery. Volumetric measurement of this GTV can predict the treatment outcomes. This volume has been limited for mere contouring and its potential as the prognostic factor is less explored.

Materials and Methods

The data of 150 patients with oropharynx, hypopharynx, and larynx cancer undergoing curative intensity-modulated RT and weekly cisplatin between April 2015 and December 2019 were retrospectively evaluated. GTV-P (primary), GTV-N (nodal), and GTV-P+N were defined, and volumetric parameters were generated. Volume thresholds were defined as per the receiver operating characteristics, and the prognostic value of these tumor volumes (TVs) with respect to treatment outcomes was analyzed.

Results

All patients completed 70 Gy, median chemotherapy cycles were six. Mean GTV-P, GTV-N, and GTV-P+N were 44.5 cc, 13.4 cc, and 57.9 cc, respectively. Oropharynx constituted 45% of cases. Forty-nine percent had Stage III disease. Sixty-six percent had complete response (CR). As per the defined cutoff values, GTV-P <30cc, GTV-N <4 cc, and GTV-P+N <50 cc had better CR rates with P < 0.05 (82.6% vs. 51.9%; 74% vs. 58.4% and 81.5% vs. 47.8%, respectively). At median follow-up of 21.4 months, overall survival (OS) was 60% and median OS was 32.3 months. The median OS in patients with GTV-P <30 cc, GTV-N <4 cc, and GTV-P+N <50 cc was better with P < 0.05 (59.2 vs. 21.4; 59.2 vs. 22.2, and 59.2 vs. 19.8 months, respectively).

Conclusion

GTV should not just be limited for contouring but its role as an important prognostic factor has to be recognized.

Semi-Automatic Volumetric and Standard Three-Dimensional Measurements for Primary Tumor Evaluation and Response to Treatment Assessment in Pediatric Rhabdomyosarcoma

Current prognostic classification of rhabdomyosarcoma in children requires precise measurements of the tumor. The purpose of the study was to compare the standard three-dimensional (3D) measurements with semi-automatic tumor volume measurement method concerning assessment of the primary tumor size and the degree of response to treatment for rhabdomyosarcoma in children. Magnetic Resonance Imaging data on 31 children with treated rhabdomyosarcoma based on the Cooperative Weichteilsarkom Studiengruppe (CWS) guidance was evaluated. Tumor sizes were measured by two methods: 3D standard measurements and semi-automatic tumor volume measurement (VOI) at diagnosis, and after 9 and 17/18 weeks of the induction chemotherapy. Response to treatment and prediction values were assessed. The tumor volume medians calculated using VOI were significantly higher in comparison with those calculated using the 3D method both during the diagnosis as well as after 9 weeks of the chemotherapy and during the 17-18th week of the treatment. The volume measurements based on the generalized estimating equations on the VOI method were significantly better than the 3D method (p = 0.037). The volumetric measurements alone can hardly be considered an unequivocal marker used to make decisions on modification of the therapy in patients with rhabdomyosarcoma.

Specific growth rates calculated from CTs in patients with head and neck squamous cell carcinoma: a retrospective study performed in Austria

OBJECTIVE

To provide data on specific growth rates (SGRs) of primary tumours (PT-SGR) and largest pathological cervical lymph nodes (LN-SGR) for head and neck squamous cell carcinoma (HNSCC). To explore PT-SGR's and LN-SGR's correlation with selected biomarkers epidermal growth factor receptor (EGFR), Ki67 and CD44.

DESIGN AND SETTING

Retrospective study performed at a tertiary oncological referral centre in Innsbruck, Austria.

PARTICIPANTS

Adult patients with incident HNSCC treated with primary radiotherapy (RT) or radiochemotherapy (RCT).

OUTCOME MEASURES

Volumes of the primary tumour (PT-volume) and largest pathological cervical lymph node (LN-volume) were measured in CT scans obtained at time of diagnosis and subsequent planning CTs immediately prior to RT or RCT. SGRs were calculated assuming an exponential growth function. PT-SGR's and LN-SGR's correlation with EGFR, Ki67 and CD44 were explored.

RESULTS

In 123 patients, mean interval between diagnostic and planning CT was 29±21 days. PT-SGR was 1.8±1.8% (mean±SD) per day and was positively correlated with EGFR, Ki67 and CD44 expression (p=0.02; p=0.02; p=0.03). LN-SGR was 1.7±2.0% per day and increased with larger initial LN-volume, was lower in laryngeal cancer (p=0.003) and slowed down with time. LN-SGR was not correlated with EGFR, Ki67 or CD44 expression in primary tumours (p>0.12). New cartilage or bone infiltration occurred in 10 patients and new central lymph node necrosis in 8 patients.

CONCLUSIONS

HNSCCs are fast-growing tumours for which treatment must not be delayed. Clinical tumour growth rates are influences by EGFR, KI67 and CD44 expression.

Prognostic value of tumor volume in patients with head and neck squamous cell carcinoma treated with primary surgery

BACKGROUND

Tumor volume in head and neck squamous cell carcinoma (HNSCC) was mainly measured in nonsurgically treated patients. We analyzed the influence of tumor volume on complete response (CR), overall survival (OS), and clear surgical margins also in primarily surgically treated patients.

METHODS

In contrast-enhanced CTs, the tumor volumes of patients with incident HNSCC were measured.

RESULTS

The tumor volumes of 259 patients were measured, of which 125 patients (48%) underwent primary surgery and 102 patients (84%) had clear margins. The tumor volume was not an independent factor for CR at the primary tumor site. Risk of death increased by 1.4% per mL of tumor volume (95% confidence interval [CI] 0.8%-2.0%; P < .001). The OS was better in patients treated with primary surgery, if the tumor volume was ≤12 mL (P < .001). Risk of involved margins increased by 4.5% per mL of tumor volume (95% CI 0.9%-8.3%; P = .003). The predicted probability of clear margins was ≥80% in tumor volumes ≤ 16 mL.

CONCLUSION

The tumor volume had an impact on CR, OS, and clear margins. The tumor volume may also aid in selecting HNSCC treatment.

Approximation of head and neck cancer volumes in contrast enhanced CT

Background

Tumor volume may serve as a predictor of response to radiochemotherapy (RCT) in head and neck squamous cell carcinoma (HNSCC). Computer assisted tumor volumetry requires time-consuming slice-by-slice manual or semi-automated segmentation. We questioned how accurately primary tumor and suspect cervical lymph node (LN) volumes can be approximated by the maximum tumor diameters in three dimensions.

Methods

In contrast-enhanced diagnostic CT scans of 74 patients with incident advanced HNSCC, manual slice-by-slice segmentation volumetry of primary tumor, total- and largest suspect cervical LN served as the reference method. In the same scans, maximum orthogonal diameters were measured using the distance measurement tool in standard visualization software in axial and coronal sections. From these diameters, approximate volumes were calculated using the cubic and ellipsoid formula. A second segmentation volumetry was performed in contrast enhanced radiotherapy-planning CT scans obtained prior to primary concurrent RCT 24 days (+/− 13 days) following the initial diagnostic CT scans. Intraclass correlation coefficients and Bland-Altman analyses were used to compare results.

Results

Slice-by-slice manual segmentation volumetry of primary and LN volumes revealed a lognormal distribution and ranged from 0 to 86 ml and 0 to 129 ml, respectively. Volume approximations in diagnostic CT scans with the ellipsoid formula resulted in an −8 % underestimation of tumor volumes (95 % CI −14 % to −1 %; p = 0.022) and an −18 % underestimation of suspect cervical LN volumes (95 % CI −25 % to −12 %; p = 0.001). Inter rater intraclass correlation for primaries was 0.95 (95 % CI +0.92 to +0.97; p = 0.001), and intra rater intraclass correlation was 0.99 (95 % CI +0.98 to +0.99; p = 0.001). The cubic formula resulted in pronounced overestimation of primary and LN volumes. Primary tumor volumes obtained by the second segmentation volumetry in radiotherapy-planning CT scans obtained on average 24 days following the initial volumetry resulted in larger primary tumor volumes (mean bias +28 %, 95 % CI +14 % to +41 %; p = 0.001). Tumor volume increase correlated with time between the diagnostic and planning CTs (r = 0.24, p = 0.05) and was approximately 1 % per day.

Discussion

Ellipsoid approximations of tumor and lymph node volumes in HNSCC using maximum orthogonal diameters underestimates volumes based on segmentation in multiple slices. Due to time difference and safety margins, segmented volumes in radiotherapy-planning CT scans tend to be larger than in diagnostic CT scans.

Conclusion

Ellipsoid approximations of tumor and lymph node volumes in HNSCC are easily available from diagnostic CT scans. Volume estimates are applicable over a wide range of tumor and LN sizes and may be useful in clinical decision-making and oncologic research.